WO2022001543A1

WO2022001543A1 - Igbt double-pulse test method and system, igbt control method, and inverter controller

Info

Publication number: WO2022001543A1
Application number: PCT/CN2021/097304
Authority: WO
Inventors: 林川川; 李启国; 蔡仕基; 周梅
Original assignee: 广汽埃安新能源汽车有限公司
Priority date: 2020-06-30
Filing date: 2021-05-31
Publication date: 2022-01-06
Also published as: CN113960437B; CN113960437A

Abstract

An IGBT double-pulse test method and system, an IGBT control method, and an inverter controller. The IGBT double-pulse test method comprises: acquiring data to be verified from an original SOA curve, wherein said data comprises a current to be tested and an original threshold voltage corresponding to said current (S201); on the basis of said current and the original threshold voltage, performing a double-pulse test on an IGBT to be tested, and acquiring a test safety voltage corresponding to said current (S202); and on the basis of said current and the test safety voltage, constructing a verification SOA curve corresponding to said IGBT (S203). The method can ensure that the construction of a verification SOA curve has sufficient test data support and is objective, and the output capability of an IGBT can be better evaluated on the basis of the verification SOA curve, thereby controlling the safe operation of the IGBT.

Description

IGBT双脉冲试验方法及***、IGBT控制方法及逆变器控制器IGBT double pulse test method and system, IGBT control method and inverter controller

本申请要求于2020年06月30日提交中国专利局、申请号为202010613023.5，发明名称为“IGBT双脉冲试验方法及***、IGBT控制方法及逆变器控制器”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。This application claims the priority of the Chinese patent application filed on June 30, 2020 with the application number 202010613023.5 and the invention title is "IGBT double-pulse test method and system, IGBT control method and inverter controller", The entire contents of which are incorporated herein by reference.

技术领域technical field

本申请涉及IGBT应用技术领域，尤其涉及一种IGBT双脉冲试验方法及***、IGBT控制方法及逆变器控制器。The present application relates to the technical field of IGBT applications, and in particular, to an IGBT double-pulse test method and system, an IGBT control method and an inverter controller.

背景技术Background technique

在电动汽车逆变器的应用环境中，由于IGBT所在电路中杂散电感的存在，使得IGBT关断时，IGBT两端会产生尖峰电压，该尖峰电压大于IGBT的耐压时，会导致IGBT损坏。为了避免上述情况发生，可采用硬件和软件两种方式进行保护，在硬件保护方式中，主要通过电压嵌位技术来降低关断尖峰电压；在软件保护方式中，主要通过降低输出电流来降低关断尖峰电压。In the application environment of electric vehicle inverters, due to the existence of stray inductance in the circuit where the IGBT is located, when the IGBT is turned off, a peak voltage will be generated at both ends of the IGBT. When the peak voltage is greater than the withstand voltage of the IGBT, the IGBT will be damaged. . In order to avoid the above situation, two methods of hardware and software can be used for protection. In the hardware protection method, the voltage clamping technology is mainly used to reduce the shutdown peak voltage; in the software protection method, the shutdown peak voltage is mainly reduced by reducing the output current. off spike voltage.

现有软件保护方式中，主要有如下两种控制策略：第一种是将最大输出电流下的电源电压确定为阈值电压，若实时检测到的实测电压大于该阈值电压时，则直接将输出电流降低为0，这种控制策略简单，但牺牲很大的IGBT的安全工作区(Safe Operating Area，简称SOA)。第二种是将最大输出电流下的电源电压确定为阈值电压，通过电源电压确定最大限值电压，若实时检测到的母线电压大于该阈值电压且小于最大限值电压时，则采用线性降电流策略将输出电流降低为0，这种方式仍不能充分利用IGBT的安全工作区，不能充分发挥IGBT的输出能力。并且，上述两种控制策略中，缺乏有效的试验方法和试验数据支撑，无法较好地评估IGBT的输出能力。In the existing software protection methods, there are mainly the following two control strategies: the first one is to determine the power supply voltage under the maximum output current as the threshold voltage, if the measured voltage detected in real time is greater than the threshold voltage, the output current is directly Reduced to 0, this control strategy is simple, but sacrifices the safe operating area (Safe Operating Area, SOA) of a large IGBT. The second is to determine the power supply voltage under the maximum output current as the threshold voltage, and determine the maximum limit voltage through the power supply voltage. If the bus voltage detected in real time is greater than the threshold voltage and less than the maximum limit voltage, a linear current drop is used. The strategy reduces the output current to 0. This method still cannot make full use of the safe working area of the IGBT, and cannot give full play to the output capability of the IGBT. Moreover, in the above two control strategies, there is a lack of effective test methods and test data support, and it is impossible to better evaluate the output capability of the IGBT.

申请内容Application content

本申请实施例提供一种IGBT双脉冲试验方法及***，以解决当前IGBT的安全工作区缺乏有效试验方法及试验数据支撑，无法较好地评估IGBT的输出能力的问题。The embodiments of the present application provide an IGBT double-pulse test method and system to solve the problem that the current safe working area of the IGBT lacks an effective test method and test data support, and the output capability of the IGBT cannot be well evaluated.

本申请实施例提供一种IGBT控制方法及逆变器控制器，以解决当前IGBT控制逻辑简单，无法充分利用IGBT的安全工作区的问题。The embodiments of the present application provide an IGBT control method and an inverter controller, so as to solve the problem that the current IGBT control logic is simple and the safe working area of the IGBT cannot be fully utilized.

本申请提供一种IGBT双脉冲试验方法，包括：The application provides an IGBT double-pulse test method, including:

从原始SOA曲线中获取待验证数据，所述待验证数据包括待测电流和与所述待测电流相对应的原始阈值电压；Obtain the data to be verified from the original SOA curve, the data to be verified includes the current to be measured and the original threshold voltage corresponding to the current to be measured;

基于所述待测电流和所述原始阈值电压，对待测IGBT进行双脉冲试验，获取与所述待测电流相对应的试验安全电压；Based on the current to be tested and the original threshold voltage, a double-pulse test is performed on the IGBT to be tested to obtain a test safety voltage corresponding to the current to be tested;

基于所述待测电流和所述试验安全电压，构建与所述待测IGBT相对应的验证SOA曲线。Based on the current to be tested and the test safety voltage, a verification SOA curve corresponding to the IGBT to be tested is constructed.

优选地，所述从原始SOA曲线中获取待验证数据，包括：Preferably, obtaining the data to be verified from the original SOA curve includes:

获取数据选取任务，所述数据选取任务包括起始数值，还包括选取数量或者选取步长；Obtaining a data selection task, the data selection task includes an initial value, and also includes a selection quantity or a selection step;

采用数据读取工具执行所述数据选取任务，基于所述起始数值和所述选取数量从所述原始SOA曲线中获取待验证数据，或者，基于所述起始数值和所述选取步长从所述原始SOA曲线中获取待验证数据。A data reading tool is used to perform the data selection task, and the data to be verified is obtained from the original SOA curve based on the initial value and the selection quantity, or, based on the initial value and the selection step size from The data to be verified is obtained from the original SOA curve.

优选地，所述基于所述待测电流和所述原始阈值电压，对待测IGBT进行双脉冲试验，获取与所述待测电流相对应的试验安全电压，包括：Preferably, based on the current to be tested and the original threshold voltage, a double-pulse test is performed on the IGBT to be tested to obtain a test safety voltage corresponding to the current to be tested, including:

调整电源电压和脉冲宽度，对待测IGBT进行双脉冲试验，使所述待测IGBT的试验实测电流达到所述待测电流，获取所述待测电流对应的试验实测电压；Adjust the power supply voltage and pulse width, perform a double-pulse test on the IGBT to be tested, so that the actual measured current of the IGBT to be tested reaches the current to be measured, and obtain the actual measured voltage of the test corresponding to the current to be measured;

基于所述待测电流对应的所述原始阈值电压和所述试验实测电压，获取所述待测电流对应的试验安全电压。Based on the original threshold voltage corresponding to the to-be-measured current and the experimentally measured voltage, the experimental safety voltage corresponding to the to-be-measured current is obtained.

优选地，所述基于所述待测电流对应的所述原始阈值电压和所述试验实测电压，获取所述待测电流对应的试验安全电压，包括：Preferably, obtaining the test safety voltage corresponding to the current to be measured based on the original threshold voltage corresponding to the current to be measured and the actual measured voltage of the test, including:

基于所述待测电流对应的试验实测电压，确定所述待测电流对应的实测最大电压；Determine the measured maximum voltage corresponding to the to-be-measured current based on the test-measured voltage corresponding to the to-be-measured current;

基于所述待测电流对应的实测最大电压，获取所述待测电流对应的原始安全电压；Based on the measured maximum voltage corresponding to the current to be measured, obtain the original safe voltage corresponding to the current to be measured;

基于所述待测电流对应的所述原始阈值电压、所述实测最大电压和所述原始安全电压，获取所述待测电流对应的试验安全电压。Based on the original threshold voltage, the measured maximum voltage, and the original safety voltage corresponding to the current to be measured, a test safety voltage corresponding to the current to be measured is obtained.

优选地，所述基于所述待测电流对应的试验实测电压，确定所述待测电流对应的实测最大电压，包括：Preferably, determining the measured maximum voltage corresponding to the to-be-measured current based on the experimentally measured voltage corresponding to the to-be-measured current includes:

将所述待测电流对应的试验实测电压中第二个尖峰电压，确定为待测电流对应的实测最大电压；Determine the second peak voltage in the experimental measured voltage corresponding to the to-be-measured current as the measured maximum voltage corresponding to the to-be-measured current;

所述基于所述待测电流对应的实测最大电压，获取所述待测电流对应的原始安全电压，包括：Obtaining the original safe voltage corresponding to the current to be measured based on the measured maximum voltage corresponding to the current to be measured includes:

将所述待测电流对应的实测最大电压之后的试验实测电压中，若当前时刻的试验实测电压与上一时刻的试验实测电压相同，则将当前时刻的试验实测电压确定为所述原始安全电压。In the test voltage after the measured maximum voltage corresponding to the current to be measured, if the test voltage at the current moment is the same as the test voltage at the previous moment, the test voltage at the current moment is determined as the original safety voltage. .

优选地，所述基于所述待测电流对应的所述原始阈值电压、所述实测最大电压和所述原始安全电压，获取所述待测电流对应的试验安全电压，包括：Preferably, obtaining the test safety voltage corresponding to the current to be measured based on the original threshold voltage, the measured maximum voltage and the original safe voltage corresponding to the current to be measured includes:

获取所述实测最大电压与所述原始阈值电压的试验电压差值，判断所述试验电压差值是否小于预设电压差值；Obtain the test voltage difference between the measured maximum voltage and the original threshold voltage, and determine whether the test voltage difference is less than a preset voltage difference;

若所述试验电压差值小于所述预设电压差值，则将所述原始安全电压确定为所述待测电流对应的试验安全电压。If the test voltage difference is smaller than the preset voltage difference, the original safe voltage is determined as the test safe voltage corresponding to the current to be measured.

优选地，在所述判断所述试验电压差值是否小于预设电压差值之后，所述IGBT双脉冲试验方法还包括：Preferably, after judging whether the test voltage difference is less than a preset voltage difference, the IGBT double-pulse test method further includes:

若所述试验电压差值不小于所述预设电压差值，则提高所述电源电压并降低脉冲宽度，对待测IGBT进行双脉冲试验，使所述待测IGBT的试验实测电流维持在所述待测电流，获取所述待测电流对应的试验实测电压，重复执行所述基于所述待测电流对应的所述原始阈值电压和所述试验实测电压，获取所述待测电流对应的试验安全电压。If the test voltage difference is not less than the preset voltage difference, increase the power supply voltage and reduce the pulse width, and perform a double-pulse test on the IGBT to be tested, so that the test current of the IGBT to be tested is maintained at the The current to be measured, the actual measured voltage of the test corresponding to the current to be measured is obtained, the original threshold voltage corresponding to the current to be measured and the measured voltage of the test are repeatedly performed, and the test safety corresponding to the current to be measured is obtained. Voltage.

上述IGBT双脉冲试验方法及***中，利用从原始SOA曲线中获取待测电流和与待测电流对应的原始阈值电压，对待测IGBT进行双脉冲试验，获取与所述待测电流相对应的试验安全电压，有助于保障试验安全电压的客观性；再基于待测电流和试验安全电压，构建与待测IGBT相对应的验证SOA曲线，可以保证验证SOA曲线的构建具有足够的试验数据支撑，具有客观性，可以基于验证SOA曲线较好评估IGBT的输出能力，并控制IGBT进行安全工作。In the above-mentioned IGBT double-pulse test method and system, the current to be measured and the original threshold voltage corresponding to the current to be measured are obtained from the original SOA curve, the double-pulse test of the IGBT to be tested is performed, and the test corresponding to the current to be measured is obtained. The safety voltage helps to ensure the objectivity of the test safety voltage; then, based on the current to be tested and the test safety voltage, the verification SOA curve corresponding to the IGBT to be tested is constructed, which can ensure that the construction of the verification SOA curve has sufficient test data support. It is objective and can better evaluate the output capability of the IGBT based on the verification SOA curve, and control the IGBT to perform safe work.

本申请提供一种IGBT双脉冲试验***，所述IGBT双脉冲试验***包括试验控制器、与所述试验控制器相连的示波器和脉冲驱动器，所述示波器和所述脉冲驱动器均与待测IGBT相连，所述试验控制器包括存储器、处理器以及存储在所述存储器中并可在所述处理器上运行的计算机可读指令，所述处理器执行所述计算机可读指令时实现如下步骤：The application provides an IGBT double-pulse test system. The IGBT double-pulse test system includes a test controller, an oscilloscope and a pulse driver connected to the test controller, and both the oscilloscope and the pulse driver are connected to the IGBT to be tested. , the test controller includes a memory, a processor, and computer-readable instructions stored in the memory and executable on the processor, and the processor implements the following steps when executing the computer-readable instructions:

本申请提供一种IGBT控制方法，包括：The present application provides an IGBT control method, including:

实时采集目标IGBT的当前实测电流和当前实测电压；Collect the current measured current and current measured voltage of the target IGBT in real time;

将与所述目标IGBT型号相同的待测IGBT对应的验证SOA曲线，确定为目标SOA曲线；Determine the verification SOA curve corresponding to the IGBT to be tested that is the same as the target IGBT model as the target SOA curve;

基于所述当前实测电流和所述目标SOA曲线，确定所述当前实测电流对应的目标阈值电压，或者，基于当前实测电压和目标SOA曲线，确定当前实测电压对应的目标阈值电流；Based on the current measured current and the target SOA curve, determine the target threshold voltage corresponding to the current measured current, or, based on the current measured voltage and the target SOA curve, determine the target threshold current corresponding to the current measured voltage;

若所述当前实测电压大于所述当前实测电流对应的目标阈值电压，或者所述当前实测电流大于所述当前实测电压对应的目标阈值电流，则执行线性降电流策略，降低所述目标IGBT的输出电流。If the current measured voltage is greater than the target threshold voltage corresponding to the current measured current, or the current measured current is greater than the target threshold current corresponding to the current measured voltage, a linear current reduction strategy is executed to reduce the output of the target IGBT current.

本申请提供一种逆变器控制器，与电动汽车逆变器的目标IGBT相连，包括存储器、处理器以及存储在所述存储器中并可在所述处理器上运行的计算机可读指令，所述处理器执行所述计算机可读指令时实现如下步骤：The present application provides an inverter controller, which is connected to a target IGBT of an electric vehicle inverter, and includes a memory, a processor, and computer-readable instructions stored in the memory and executable on the processor. The processor implements the following steps when executing the computer-readable instructions:

上述IGBT控制方法及逆变器控制器中，利用当前实测电流查询目标SOA曲线，确定当前实测电流对应的目标阈值电压，或者利用当前实测电压查询目标SOA曲线，确定当前实测电压对应的目标阈值电流；并在当前实测电压大于当前实测电流对应的目标阈值电压或者当前实测电流大于当前实测电压对应的目标阈值电流时，执行线性降电流策略，降低目标IGBT的输出电流，可避免目标IGBT关断瞬间产生的尖峰电压损坏目标IGBT，并充分利用目标IGBT的安全工作区，使得目标IGBT的工作区间较大，充分发挥目标IGBT的输出能力，而且可以保证输出电流调节的平缓性。In the above IGBT control method and inverter controller, the current measured current is used to query the target SOA curve to determine the target threshold voltage corresponding to the current measured current, or the current measured voltage is used to query the target SOA curve to determine the target threshold current corresponding to the current measured voltage ; And when the current measured voltage is greater than the target threshold voltage corresponding to the current measured current or the current measured current is greater than the target threshold current corresponding to the current measured voltage, a linear current reduction strategy is executed to reduce the output current of the target IGBT, which can avoid the moment when the target IGBT is turned off. The generated peak voltage damages the target IGBT, and makes full use of the safe working area of the target IGBT, making the working range of the target IGBT larger, giving full play to the output capability of the target IGBT, and ensuring the smoothness of the output current regulation.

附图说明Description of drawings

为了更清楚地说明本申请实施例的技术方案，下面将对本申请实施例的描述中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本申请的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动性的前提下，还可以根据这些附图获得其他的附图。In order to illustrate the technical solutions of the embodiments of the present application more clearly, the following briefly introduces the drawings that are used in the description of the embodiments of the present application. Obviously, the drawings in the following description are only some embodiments of the present application. , for those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative labor.

图1是本申请一实施例中IGBT双脉冲试验电路的一示意图；1 is a schematic diagram of an IGBT double-pulse test circuit in an embodiment of the present application;

图2是本申请一实施例中IGBT双脉冲试验方法的一流程图；Fig. 2 is a flow chart of the IGBT double-pulse test method in an embodiment of the present application;

图3是本申请一实施例中IGBT双脉冲试验方法的另一流程图；3 is another flowchart of the IGBT double-pulse test method in an embodiment of the present application;

图4是本申请一实施例中IGBT双脉冲试验方法的另一流程图；4 is another flowchart of the IGBT double-pulse test method in an embodiment of the present application;

图5是本申请一实施例中IGBT双脉冲试验方法的另一流程图；5 is another flowchart of the IGBT double-pulse test method in an embodiment of the present application;

图6是本申请一实施例中IGBT双脉冲试验方法的另一流程图；6 is another flowchart of the IGBT double-pulse test method in an embodiment of the present application;

图7是本申请一实施例中IGBT双脉冲试验方法的另一流程图；7 is another flowchart of the IGBT double-pulse test method in an embodiment of the present application;

图8是本申请一实施例中IGBT控制方法的一流程图；8 is a flowchart of an IGBT control method in an embodiment of the present application;

图9是本申请一实施例中原始SOA曲线的一示意图；9 is a schematic diagram of an original SOA curve in an embodiment of the present application;

图10是本申请一实施例中试验SOA曲线的一示意图；10 is a schematic diagram of a test SOA curve in an embodiment of the present application;

图11是本申请一实施例中IGBT双脉冲试验方法中的一信号示意图。FIG. 11 is a schematic diagram of a signal in an IGBT double-pulse test method according to an embodiment of the present application.

具体实施方式detailed description

下面将结合本申请实施例中的附图，对本申请实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例是本申请一部分实施例，而不是全部的实施例。基于本申请中的实施例，本领域普通技术人员在没有作出创造性劳动前提下所获得的所有其他实施例，都属于本申请保护的范围。The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

本申请实施例提供的IGBT双脉冲试验方法，该IGBT双脉冲试验方法应用在IGBT双脉冲试验***中，IGBT双脉冲试验***包括试验控制器、与试验控制器相连的示波器和脉冲驱动器，示波器和脉冲驱动器均与待测IGBT相连，试验控制器包括存储器、处理器以及存储在存储器中并可在处理器上运行的计算机可读指令，处理器执行计算机可读指令时实现下述实施例所提供的IGBT双脉冲试验方法。The IGBT double-pulse test method provided in the embodiment of the present application is applied in an IGBT double-pulse test system. The IGBT double-pulse test system includes a test controller, an oscilloscope and a pulse driver connected to the test controller. The oscilloscope and The pulse drivers are all connected to the IGBT to be tested, and the test controller includes a memory, a processor, and computer-readable instructions stored in the memory and running on the processor. When the processor executes the computer-readable instructions, the following embodiments provide IGBT double pulse test method.

该IGBT双脉冲试验方法可应用在图1所示的IGBT双脉冲试验电路中，该IGBT双脉冲试验电路包括高压直流电源U、与高压直流电源U的正极相连的IGBT上管Q1、与IGBT上管Q1和高压直流电源U的负极相连的IGBT下管Q2、与高压直流电源U并联设置的支撑电容C、与IGBT上管Q1并联设置的绕线电感L，IGBT上管Q1的两端设有反向续流二极管D1，IGBT下管Q2的两端设有反向续流二极管D2。Ls1/Ls2/Ls3/Ls4/Ls5/Ls6/Ls7/Ls8等为IGBT双脉冲试验电路中的杂散电感。本示例中，IGBT上管Q1的门极上加负压，使IGBT上管Q1关断，只有反向续流二极管D1在起作用，可以采用单个二极管替代IGBT上管Q1和反向续流二极管D1，此时，IGBT下管Q2为待测IGBT。脉冲驱动器与IGBT下管Q2相连，用于向IGBT下管Q2发送双脉冲驱动信号，以控制IGBT下管Q2工作。示波器与Vce辅助端子和Vce功率端子相连，用于采集执行IGBT双脉冲试验方法过程中形成的验证实测数据，该验证实测数据包括试验实测电流和试验实测电压。The IGBT double-pulse test method can be applied to the IGBT double-pulse test circuit shown in FIG. 1 . The IGBT double-pulse test circuit includes a high-voltage DC power supply U, an IGBT upper tube Q1 connected to the positive electrode of the high-voltage DC power supply U, and an IGBT upper tube Q1. The IGBT lower tube Q2 connected with the negative pole of the high-voltage DC power supply U, the supporting capacitor C arranged in parallel with the high-voltage DC power supply U, the winding inductance L arranged in parallel with the IGBT upper tube Q1, the two ends of the IGBT upper tube Q1 are provided with The reverse freewheeling diode D1 and the two ends of the IGBT lower tube Q2 are provided with a reverse freewheeling diode D2. Ls1/Ls2/Ls3/Ls4/Ls5/Ls6/Ls7/Ls8 are the stray inductances in the IGBT double-pulse test circuit. In this example, a negative voltage is applied to the gate of the IGBT top transistor Q1, so that the IGBT top transistor Q1 is turned off, and only the reverse freewheeling diode D1 works. A single diode can be used to replace the IGBT top transistor Q1 and the reverse freewheeling diode. D1, at this time, the IGBT lower tube Q2 is the IGBT to be tested. The pulse driver is connected with the IGBT lower tube Q2, and is used for sending a double-pulse driving signal to the IGBT lower tube Q2, so as to control the IGBT lower tube Q2 to work. The oscilloscope is connected to the Vce auxiliary terminal and the Vce power terminal, and is used to collect the verified and measured data formed during the implementation of the IGBT double-pulse test method. The verified and measured data includes the test current and test voltage.

在开始双脉冲试验之前，采用高压直流电源U给支撑电容C充电，以使支撑电容C上存储有足够的电容，在双脉冲试验过程中，可以将支撑电容C作为IGBT双脉冲试验电路的供电电源。在双脉冲试验过程中，采用柔性电流探头接入到接入Vce辅助端子，以使与柔性电流探头相连的示波器可以实时采集待测IGBT的试验实测电流；采用高压隔离探头接入Vce功率端子，以使与高压隔离探头相连的示波器可以实时采集待测IGBT的试验实测电压。在双脉冲试验过程中，试验控制器与脉冲驱动器和示波器相连，通过控制脉冲驱动器输出双脉冲驱动信号，以使待测IGBT工作，再通过示波器采集试验实测电流和试验实测电压等验证实测数据，基于验证实测数据完成下述实施例中的IGBT双脉冲试验方法。Before starting the double-pulse test, use the high-voltage DC power supply U to charge the support capacitor C so that enough capacitance is stored on the support capacitor C. During the double-pulse test, the support capacitor C can be used as the power supply for the IGBT double-pulse test circuit power supply. During the double-pulse test, the flexible current probe is used to connect to the auxiliary terminal of Vce, so that the oscilloscope connected to the flexible current probe can collect the actual current measured in the test of the IGBT to be tested in real time; the high-voltage isolation probe is used to connect to the Vce power terminal, So that the oscilloscope connected with the high-voltage isolation probe can collect the test voltage of the IGBT to be tested in real time. During the double-pulse test, the test controller is connected to the pulse driver and the oscilloscope, and outputs the double-pulse drive signal by controlling the pulse driver to make the IGBT to be tested work. Based on the verified measured data, the IGBT double-pulse test method in the following embodiment is completed.

在一实施例中，如图2所示，提供一种IGBT双脉冲试验方法，以该IGBT双脉冲试验方法应用在图1中的试验控制器为例，该IGBT双脉冲试验方法包括试验控制器执行的如下步骤：In one embodiment, as shown in FIG. 2 , an IGBT double-pulse test method is provided. Taking the IGBT double-pulse test method applied to the test controller in FIG. 1 as an example, the IGBT double-pulse test method includes a test controller. The following steps are performed:

S201：从原始SOA曲线中获取待验证数据，待验证数据包括待测电流和与待测电流相对应的原始阈值电压。S201: Acquire data to be verified from the original SOA curve, where the data to be verified includes a current to be measured and an original threshold voltage corresponding to the current to be measured.

其中，原始SOA曲线是预先配置的待测IGBT的反向偏置安全工作区所形成的曲线。作为一示例，该原始SOA曲线可以理解为待测IGBT在生产设计过程，反映待测IGBT两端的电流及其安全电压之间关系的曲线。如图9所示，图中芯片SOA曲线对应的虚线为反映待测IGBT的电流与其安全电压之间关系的理论曲线，是指不考虑待测IGBT所在的电路存在杂散电感时对应的理论曲线；图中原始SOA曲线对应的实线为反映待测IGBT的电流与其安全电压之间关系的理论曲线，是指考虑待测IGBT所在的电路存在杂散电感时对应的理论曲线。Among them, the original SOA curve is the curve formed by the reverse bias safe operating area of the pre-configured IGBT to be tested. As an example, the original SOA curve can be understood as a curve reflecting the relationship between the current at both ends of the IGBT to be tested and its safety voltage during the production design process of the IGBT to be tested. As shown in Figure 9, the dotted line corresponding to the SOA curve of the chip in the figure is a theoretical curve reflecting the relationship between the current of the IGBT to be tested and its safety voltage, which refers to the theoretical curve corresponding to the stray inductance of the circuit where the IGBT to be tested is not considered. ; The solid line corresponding to the original SOA curve in the figure is the theoretical curve reflecting the relationship between the current of the IGBT to be tested and its safety voltage, which refers to the corresponding theoretical curve when the circuit where the IGBT to be tested has stray inductance is considered.

其中，待测电流是指需要在双脉冲试验过程中控制试验实测电流跟随的电流。与待测电流相对应的原始阈值电压是指基于待测电流查询原始SOA曲线，从原始SOA曲线中读取到的与待测电流相对应的电压。该原始阈值电压可以理解为待测IGBT的电流为待测电流时，其待测IGBT两端可以正常工作的安全电压。Among them, the current to be measured refers to the current that needs to be followed by the measured current in the control test during the double-pulse test. The original threshold voltage corresponding to the current to be measured refers to the voltage corresponding to the current to be measured that is read from the original SOA curve by querying the original SOA curve based on the current to be measured. The original threshold voltage can be understood as the safe voltage at which both ends of the IGBT to be tested can work normally when the current of the IGBT to be tested is the current to be tested.

作为一示例，在双脉冲试验过程中，用户可以通过输入设备(如键盘、鼠标或者其他设备)，从原始SOA曲线中选取多个待测电流，以使试验控制器可从原始SOA曲线中获取待验证数据，该待验证数据包括待测电流和与待测电流相对应的原始阈值电压，如下表一所示。As an example, during the double-pulse test, the user can select multiple currents to be tested from the original SOA curve through an input device (such as a keyboard, mouse or other devices), so that the test controller can obtain the original SOA curve from the original SOA curve Data to be verified, the data to be verified includes the current to be measured and the original threshold voltage corresponding to the current to be measured, as shown in Table 1 below.

表一待验证数据Table 1 Data to be verified

S202：基于待测电流和原始阈值电压，对待测IGBT进行双脉冲试验，获取与待测电流相对应的试验安全电压。S202: Based on the current to be tested and the original threshold voltage, a double-pulse test is performed on the IGBT to be tested to obtain a test safety voltage corresponding to the current to be tested.

其中，试验安全电压是通过双脉冲试验确定的可以反映待测IGBT可以安全工作的电压，即IGBT的集电极和发射极之间的电压Vce。由于IGBT双脉冲试验电路中，Ls1/Ls2/Ls3/Ls4/Ls5/Ls6/Ls7/Ls8等杂散电感的存在，为了避免杂散电感导致IGBT关断时产生的尖峰电压损坏IGBT，需控制待测IGBT在试验安全电压以下工作。Among them, the test safety voltage is determined by the double-pulse test and can reflect the voltage that the IGBT to be tested can work safely, that is, the voltage Vce between the collector and the emitter of the IGBT. Due to the existence of stray inductances such as Ls1/Ls2/Ls3/Ls4/Ls5/Ls6/Ls7/Ls8 in the IGBT double-pulse test circuit, in order to prevent the stray inductance from causing the IGBT to be turned off due to the spike voltage that damages the IGBT, it is necessary to control the Test the IGBT to work below the test safety voltage.

本示例中，试验控制器获取到的待验证数据包括至少两个待测电流和对应的原始阈值电压，如上表一中的Ic1-Vce th1和Ic2-Vce th2等；针对每一个待测电流和对应的原始阈值电压，可输入双脉冲试验的调节变量，对待测IGBT进行双脉冲试验，以使示波器实时采集待测IGBT的试验实测电流达到待测电流，并通过示波器实时采集待测IGBT集电极和发射极之间的试验实测电压，再采用预先配置的用于确定试验安全电压的安全电压确定逻辑，对试验实测电压和原始阈值电压进行处理，从而确定与待测电流相对应的试验安全电压，如下表二中的Vce1和Vce2等。本示例中，双脉冲试验的调节变量包括高压直流电源U的电源电压VDC和脉冲宽度，该电源电压VDC和脉冲宽度可以根据实际情况自主设置。In this example, the data to be verified obtained by the test controller includes at least two currents to be measured and corresponding original threshold voltages, such as Ic1-Vce th1 and Ic2-Vce th2 in Table 1 above; for each current to be measured and Corresponding original threshold voltage, the adjustment variable of the double-pulse test can be input, and the double-pulse test of the IGBT to be tested can be carried out, so that the oscilloscope can collect the test current of the IGBT to be tested in real time to reach the current to be tested, and collect the collector of the IGBT to be tested in real time through the oscilloscope. The test voltage between the test voltage and the emitter, and then use the pre-configured safety voltage determination logic for determining the test safety voltage to process the test test voltage and the original threshold voltage to determine the test safety voltage corresponding to the current to be measured. , Vce1 and Vce2 in Table 2 below. In this example, the adjustment variables of the double-pulse test include the power supply voltage VDC and the pulse width of the high-voltage DC power supply U, and the power supply voltage VDC and pulse width can be set independently according to the actual situation.

表二数据记录表(一)Table 2 Data record table (1)

电流Ic(A)Current Ic(A)	Vce th(V)Vce th(V)	Vce(V)(记录)Vce(V) (record)
Ic1(例840)Ic1 (Example 840)	Vce th1Vce th1	Vce1Vce1
Ic2(例800)Ic2 (Example 800)	Vce th2Vce th2	Vce2Vce2
Ic3(例700)Ic3 (Example 700)	Vce th3Vce th3	Vce3Vce3
Ic4(例600)Ic4 (Example 600)	Vce th4Vce th4	Vce4Vce4
Ic5(例500)Ic5 (Example 500)	Vce th5Vce th5	Vce5Vce5
Ic6(例400)Ic6 (Example 400)	Vce th6Vce th6	Vce6Vce6
Ic7(例300)Ic7 (Example 300)	Vce th7Vce th7	Vce7Vce7
Ic8(例200)Ic8 (Example 200)	Vce th8Vce th8	Vce8Vce8
Ic9(例100)Ic9 (Example 100)	Vce th9Vce th9	Vce9Vce9

S203：基于待测电流和试验安全电压，构建与待测IGBT相对应的验证SOA曲线。S203: Based on the current to be tested and the test safety voltage, construct a verification SOA curve corresponding to the IGBT to be tested.

其中，验证SOA曲线是根据待测电流和试验安全电压确定的反向偏置安全工作区所形成的曲线。如图10所示，该验证SOA曲线可以反映待测IGBT应用在IGBT双脉冲试验电路等实际电路中存在杂散电感时，待测IGBT的反向偏置安全工作区所形成的曲线。Among them, the verification SOA curve is a curve formed by the reverse bias safe working area determined according to the current to be measured and the test safe voltage. As shown in Figure 10, the verification SOA curve can reflect the curve formed by the reverse bias safe working area of the IGBT to be tested when there is stray inductance in the actual circuit such as the IGBT double-pulse test circuit to be tested.

本示例中，试验控制器获取多组待测电流和试验安全电压，如Ic1-Vce1、Ic2-Vce2和Ic3-Vce3等，再采用曲线拟合工具对所有待测电流和对应的试验安全电压进行拟合，以构建与待测IGBT相对应的验证SOA曲线，以使该验证SOA曲线可以反映待测IGBT实际工作的反向偏置安全工作区，以便基于验证SOA曲线对其他IGBT进行安全控制。该曲线拟合工具是可以执行曲线拟合算法的工具。In this example, the test controller obtains multiple sets of test currents and test safety voltages, such as Ic1-Vce1, Ic2-Vce2 and Ic3-Vce3, etc., and then uses a curve fitting tool to perform all test currents and corresponding test safety voltages. Fitting to construct a verification SOA curve corresponding to the IGBT to be tested, so that the verification SOA curve can reflect the reverse bias safe working area of the actual operation of the IGBT to be tested, so that other IGBTs can be safely controlled based on the verification SOA curve. The curve fitting tool is a tool that can perform curve fitting algorithms.

作为进一步改进，可以采用同一型号的多个待测IGBT进行双脉冲试验，以使试验控制器可以基于同一型号的多个待测IGBT进行双脉冲试验所获取的待测电流和试验安全电压，拟合出同一型号对应的待测IGBT的验证SOA曲线，以便利用该验证SOA曲线对与待测IGBT同一型号的其他IGBT进行安全控制。As a further improvement, multiple IGBTs to be tested of the same model can be used for the double-pulse test, so that the test controller can be based on the current to be tested and the test safety voltage obtained from the double-pulse test of multiple IGBTs to be tested of the same model. The verification SOA curve of the IGBT to be tested corresponding to the same model is combined, so that the verification SOA curve can be used to safely control other IGBTs of the same type as the IGBT to be tested.

本实施例所提供的IGBT双脉冲试验方法中，利用从原始SOA曲线中获取待测电流和与待测电流对应的原始阈值电压，对待测IGBT进行双脉冲试验，获取与待测电流相对应的试验安全电压，有助于保障试验安全电压的客观性；再基于待测电流和试验安全电压，构建与待测IGBT相对应的验证SOA曲线，可以保证验证SOA曲线的构建具有足够的试验数据支撑，具有客观性，可以基于验证SOA曲线较好评估IGBT的输出能力，并控制IGBT进行安全工作。In the IGBT double-pulse test method provided in this embodiment, the current to be measured and the original threshold voltage corresponding to the current to be measured are obtained from the original SOA curve, and the double-pulse test of the IGBT to be tested is performed to obtain the current corresponding to the current to be measured. The test safety voltage helps to ensure the objectivity of the test safety voltage; and then based on the current to be tested and the test safety voltage, the verification SOA curve corresponding to the IGBT to be tested is constructed, which can ensure that the construction of the verification SOA curve has sufficient test data support , which is objective, and can better evaluate the output capability of the IGBT based on the verification SOA curve, and control the IGBT to perform safe work.

在一实施例中，由于用户操作输入设备从原始SOA曲线中获取待验证数据的过程存在耗时长且效率较低的问题，为了克服手动操作存在的上述问题，可以采用自动操作方式，以提高待验证数据的获取效率。如图3所示，步骤S201，即从原始SOA曲线中获取待验证数据，包括如下步骤：In one embodiment, since the process of obtaining the data to be verified from the original SOA curve by the user operating the input device has the problem of time-consuming and low efficiency, in order to overcome the above-mentioned problems existing in the manual operation, an automatic operation mode can be adopted to improve the efficiency of the data to be verified. Verify data acquisition efficiency. As shown in Fig. 3, step S201, that is, obtaining the data to be verified from the original SOA curve, includes the following steps:

S301：获取数据选取任务，数据选取任务包括起始数值，还包括选取数量或者选取步长。S301: Obtain a data selection task, where the data selection task includes a starting value, and also includes a selection quantity or a selection step size.

S302：采用数据读取工具执行数据选取任务，基于起始数值和选取数量从原始SOA曲线中获取待验证数据，或者，基于起始数值和选取步长从原始SOA曲线中获取待验证数据。S302: Use a data reading tool to perform the data selection task, and obtain the data to be verified from the original SOA curve based on the initial value and the selection quantity, or obtain the data to be verified from the original SOA curve based on the initial value and the selection step size.

其中，数据选取任务是用户自主配置的用于从原始SOA曲线中选取待验证数据的任务。起始数值是用户自主配置的第一个待测电流。选取数量是用户自主配置的需要选取待验证数据的数量。选取步长是用户自主配置的需要反映相邻两个待测电流之间的差值。数据读取工具是预先设置的可从原始SOA曲线中读取数据的工作，如Getdata软件。The data selection task is a task configured by the user to select the data to be verified from the original SOA curve. The initial value is the first current to be measured configured by the user. The selected quantity is the quantity of the data to be verified that needs to be selected by the user's self-configured configuration. The selected step size is configured by the user and needs to reflect the difference between two adjacent currents to be measured. Data reading tools are pre-configured jobs that read data from raw SOA curves, such as Getdata software.

作为一示例，试验控制器接收数据选取任务，该数据选取任务包括起始数值和选取数量，采用数据读取工具执行数据选取任务，基于起始数值和选取数量，从原始SOA曲线中获取待验证数据。例如，可设置起始数值Ic为原始SOA曲线中的最大值，选取数量为10，则计算原始SOA曲线中的最大值与最小值的差值，再将计算出的差值除以10，以确定10个待测电流和与待测电流对应的原始阈值电压。可以理解地，试验控制器中预先存储基于起始数值和选取数量进行逻辑计算，确定所有待测电流对应的第一处理逻辑，以使试验控制器执行数据选取任务时，可执行该第一处理逻辑，获取待验证数据，提高待验证数据的获取效率，降低获取时长。As an example, the test controller receives a data selection task, the data selection task includes an initial value and a selection quantity, uses a data reading tool to perform the data selection task, and obtains the to-be-verified data from the original SOA curve based on the initial value and the selection quantity data. For example, the initial value Ic can be set as the maximum value in the original SOA curve, and the selected number is 10, then calculate the difference between the maximum value and the minimum value in the original SOA curve, and then divide the calculated difference by 10 to get Determine the 10 currents to be measured and the original threshold voltage corresponding to the currents to be measured. It can be understood that the test controller pre-stores logic calculation based on the initial value and the selected quantity, and determines the first processing logic corresponding to all the currents to be measured, so that when the test controller performs the data selection task, the first processing can be performed. Logic, to obtain the data to be verified, improve the efficiency of obtaining the data to be verified, and reduce the acquisition time.

作为另一示例，试验控制器接收数据选取任务，该数据选取任务包括起始数值和选取步长，采用数据读取工作执行数据选取任务，基于起始数值和选取步长，从原始SOA曲线中获取待验证数据。例如，可设置起始数值Ic为100A，选取步长为100A，则其选取的待测电流为100A、200A和300A等，并相应确定原始阈值电压。可以理解地，试验控制器中预先存储基于起始数值和选取步长进行逻辑计算，确定所有待测电流对应的第二处理逻辑，以使试验控制器执行数据选取任务时，可执行该第二处理逻辑，获取待验证数据，降低获取时长。As another example, the test controller receives a data selection task, the data selection task includes a starting value and a selection step, uses the data reading job to perform the data selection task, and based on the starting value and the selection step, from the original SOA curve Get the data to be verified. For example, the initial value Ic can be set to 100A, and the selected step size is 100A, then the selected currents to be measured are 100A, 200A, 300A, etc., and the original threshold voltage is determined accordingly. It can be understood that the logic calculation based on the initial value and the selection step is pre-stored in the test controller, and the second processing logic corresponding to all the currents to be measured is determined, so that when the test controller performs the data selection task, the second processing logic can be executed. Processing logic to obtain the data to be verified and reduce the acquisition time.

在一实施例中，如图4所示，步骤S202，即基于待测电流和原始阈值电压，对待测IGBT进行双脉冲试验，获取与待测电流相对应的试验安全电压，包括如下步骤：In one embodiment, as shown in FIG. 4 , step S202, that is, based on the current to be tested and the original threshold voltage, perform a double-pulse test on the IGBT to be tested to obtain a test safety voltage corresponding to the current to be tested, including the following steps:

S401：调整电源电压和脉冲宽度，对待测IGBT进行双脉冲试验，使待测IGBT的试验实测电流达到待测电流，获取待测电流对应的试验实测电压。S401: Adjust the power supply voltage and pulse width, perform a double-pulse test on the IGBT to be tested, so that the actual measured current of the IGBT to be tested reaches the current to be measured, and obtain the actual measured voltage of the test corresponding to the current to be measured.

本示例中，每次进行双脉冲试验之前，先调整电源电压至电压下限值，以避免后续进行双脉冲试验过程中，由于电源电压过多而影响双脉冲试验的正常进行；再根据实际情况调整脉冲宽度，以完成调节变量配置。接着，试验控制器基于调整后的电源电压和脉冲宽度这两个调节变量，控制脉冲驱动器形成双脉冲驱动信号，以控制待测IGBT进行双脉冲试验，使待测IGBT的试验实测电流达到待测电流，并通过示波器实际采集双脉冲试验过程中待测电流对应的试验实测电压。其中，电压下限值是预先设置的用于进行双脉冲试验过程中的较小电压值，可有助于保障双脉冲试验的正常运行。In this example, before each double-pulse test, the power supply voltage should be adjusted to the lower voltage limit to avoid the double-pulse test being affected by excessive power supply voltage during the subsequent double-pulse test. Adjust the pulse width to complete the manipulated variable configuration. Next, the test controller controls the pulse driver to form a double-pulse drive signal based on the two adjustment variables of the adjusted power supply voltage and pulse width, so as to control the IGBT to be tested to perform a double-pulse test, so that the actual measured current of the IGBT to be tested reaches the level to be tested. The current, and the actual test voltage corresponding to the current to be measured during the double-pulse test is actually collected by the oscilloscope. The voltage lower limit value is a preset smaller voltage value used in the process of the double-pulse test, which can help to ensure the normal operation of the double-pulse test.

例如，以表一所示的Ic1(例840)-Vce th1为例，先调整电源电压为电压下限值400V，再根据实际情况调整脉冲宽度；根据设置好的电源电压和脉冲宽度控制脉冲驱动器形输出双脉冲驱动信号(如图11中Vge对应的曲线)，对待测IGBT进行双脉冲试验，使得示波器实时采集到的试验实测电流达到待测电流(如图11中Ic对应的曲线)，实时采集待测电流对应的试验实测电压(如图11中Vce对应的实线)，此时，待测电流对应的原始阈值电压为图11中Vce对应的虚线。For example, take Ic1 (Example 840)-Vce th1 shown in Table 1 as an example, first adjust the power supply voltage to the lower voltage limit of 400V, and then adjust the pulse width according to the actual situation; control the pulse driver according to the set power supply voltage and pulse width The double-pulse driving signal (curve corresponding to Vge in Fig. 11) is output in the form of a double-pulse test of the IGBT to be tested, so that the actual measured current collected by the oscilloscope in real time reaches the current to be tested (curve corresponding to Ic in Fig. 11). Collect the experimentally measured voltage corresponding to the current to be measured (the solid line corresponding to Vce in Figure 11 ). At this time, the original threshold voltage corresponding to the current to be measured is the dotted line corresponding to Vce in Figure 11 .

S402：基于待测电流对应的原始阈值电压和试验实测电压，获取待测电流对应的试验安全电压。S402 : Based on the original threshold voltage corresponding to the current to be measured and the actual measured voltage in the test, obtain a safe test voltage corresponding to the current to be measured.

本示例中，试验控制器在获取待测电流对应的试验实测电压和原始阈值电压之后，可调整预先配置的用于确定试验安全电压的安全电压确定逻辑，对试验实测电压和原始阈值电压进行处理，从而确定与待测电流相对应的试验安全电压，该试验安全电压可以理解为从图11中的待测电流对应的试验实测电压中，选取出的可以反映待测IGBT可以安全工作的电压。本示例中，该安全电压确定逻辑是用户根据实际情况自主配置的用于对试验实测电压和原始阈值电压进行处理的逻辑，可以包括但不限于减法运算逻辑、大小比较逻辑和其他逻辑，只需保证其可以获取最大范围的试验安全电压即可。In this example, the test controller can adjust the pre-configured safety voltage determination logic for determining the test safety voltage after obtaining the test measured voltage and the original threshold voltage corresponding to the current to be tested, and process the test measured voltage and the original threshold voltage. , so as to determine the test safety voltage corresponding to the current to be tested. The test safety voltage can be understood as the voltage selected from the actual measured voltages of the test corresponding to the current to be tested in FIG. 11 that can reflect the safe operation of the IGBT to be tested. In this example, the safety voltage determination logic is the logic configured by the user according to the actual situation and used to process the test voltage and the original threshold voltage, which may include but not limited to subtraction logic, size comparison logic and other logics. It is enough to ensure that it can obtain the maximum range of test safety voltage.

本实施例所提供的IGBT双脉冲试验方法中，通过调整电源电压和脉冲宽度这两个调节变量，对待测IGBT进行双脉冲试验，使待测IGBT的试验实测电流达到待测电流，获取待测电流对应的试验实测电压，该试验实测电压是在杂散电压存在的情况下实时采集到的电压，可以保证试验实测电压的客观性；再基于试验实测电压和原始阈值电压确定试验安全电压，从而保证试验安全电压的客观性和准确性。In the IGBT double-pulse test method provided in this embodiment, by adjusting the two adjustment variables of power supply voltage and pulse width, the double-pulse test of the IGBT to be tested is carried out, so that the test current of the IGBT to be tested reaches the current to be tested, and the test current of the IGBT to be tested is obtained. The test voltage corresponding to the current, the test voltage is the voltage collected in real time in the presence of stray voltage, which can ensure the objectivity of the test voltage; and then determine the test safety voltage based on the test voltage and the original threshold voltage, so as to Ensure the objectivity and accuracy of the test safety voltage.

在一实施例中，如图5所示，步骤S402，即基于待测电流对应的原始阈值电压和试验实测电压，获取待测电流对应的试验安全电压，包括如下步骤：In one embodiment, as shown in FIG. 5 , step S402, that is, obtaining the test safety voltage corresponding to the current to be measured based on the original threshold voltage corresponding to the current to be measured and the actual measured voltage of the test, including the following steps:

S501：基于待测电流对应的试验实测电压，确定待测电流对应的实测最大电压。S501: Determine the measured maximum voltage corresponding to the to-be-measured current based on the test-measured voltage corresponding to the to-be-measured current.

其中，实测最大电压是指在双脉冲试验过程中实际采集的试验实测电压中的最大值。本示例中，试验控制器在获取到双脉冲试验过程采集到所有试验实测电压之后，从所有试验实测电压中确定待测电流对应的实测最大电压。一般来说，待测IGBT的实测最大电压是在待测IGBT关断瞬间形成的试验实测电压，可以理解为尖峰电压。Among them, the measured maximum voltage refers to the maximum value of the test measured voltages actually collected during the double-pulse test. In this example, the test controller determines the measured maximum voltage corresponding to the current to be measured from all the test measured voltages after acquiring all the test measured voltages during the double-pulse test. Generally speaking, the measured maximum voltage of the IGBT to be tested is the measured voltage of the test formed at the moment when the IGBT to be tested is turned off, which can be understood as a peak voltage.

S502：基于待测电流对应的实测最大电压，获取待测电流对应的原始安全电压。S502: Based on the measured maximum voltage corresponding to the current to be measured, obtain the original safe voltage corresponding to the current to be measured.

其中，原始安全电压是指一次双脉冲试验所采集的试验实测电压，确定的待测IGBT的安全电压，即基于电源电压和脉冲宽度这两个调节变量进行双脉冲试验所确定的安全电压。Among them, the original safety voltage refers to the actual measured voltage collected by a double-pulse test, and the determined safety voltage of the IGBT to be tested, that is, the safety voltage determined by the double-pulse test based on the two adjustment variables of power supply voltage and pulse width.

本示例中，试验控制器在确定待测电流对应的实测最大电压之后，从实测最大电压之后的所有试验实测电压中，选取相邻时刻大小相同的试验实测电压确定为待测IGBT对应的原始安全电压。可以理解地，在实测最大电压之后的所有试验实测电压中，若试验实测电压在相邻时刻大小相同，说明其试验实测电压没有发生变化，说明此时待测IGBT已经正常工作，因此，可将该试验实测电压确定为原始安全电压。In this example, after the test controller determines the measured maximum voltage corresponding to the current to be measured, it selects the test measured voltage with the same magnitude at adjacent moments from all the test measured voltages after the measured maximum voltage and determines it as the original safety corresponding to the IGBT to be tested. Voltage. Understandably, among all the test voltages after the actual maximum voltage is measured, if the test voltages are the same at adjacent times, it means that the test voltage has not changed, indicating that the IGBT to be tested has been working normally at this time. The measured voltage of this test is determined as the original safe voltage.

S503：基于待测电流对应的原始阈值电压、实测最大电压和原始安全电压，获取待测电流对应的试验安全电压。S503: Obtain a test safety voltage corresponding to the current to be measured based on the original threshold voltage, the measured maximum voltage, and the original safe voltage corresponding to the current to be measured.

由于待测电流对应的原始阈值电压是基于待测电流读取原始SOA曲线所确定的电压。待测电流对应的实测最大电压和原始安全电压是基于一次调整电源电压和脉冲宽度，对待测IGBT进行双脉冲试验所采集到的试验实测电压所确定的电压，具有客观性。本示例中，试验控制器在获取到原始阈值电压、实测最大电压和原始安全电压之后，可以采用预先设置的安全电压校验逻辑，对原始阈值电压、实测最大电压和原始安全电压进行校验，以将校验合格的原始安全电压能否确定为待测电流对应的试验安全电压。其中，安全电压校验逻辑是安全电压确定逻辑的一部分，主要用于利用原始阈值电压和实测最大电压进行逻辑判断，以校验原始安全电压能否确定为待测电流对应的试验安全电压，若校验合格，则将原始安全电压确定为试验安全电压，从而保证试验安全电压的客观性和准确性。Since the original threshold voltage corresponding to the current to be measured is a voltage determined by reading the original SOA curve based on the current to be measured. The measured maximum voltage and the original safe voltage corresponding to the current to be measured are based on the voltage determined by the measured voltage collected from the double-pulse test of the IGBT to be measured based on one-time adjustment of the power supply voltage and pulse width, and are objective. In this example, after obtaining the original threshold voltage, the measured maximum voltage and the original safe voltage, the test controller can use the preset safety voltage verification logic to verify the original threshold voltage, measured maximum voltage and original safe voltage. In order to determine whether the original safe voltage that has passed the verification can be determined as the test safe voltage corresponding to the current to be measured. Among them, the safety voltage verification logic is a part of the safety voltage determination logic, which is mainly used for logical judgment by using the original threshold voltage and the measured maximum voltage to verify whether the original safety voltage can be determined as the test safety voltage corresponding to the current to be measured. If the calibration is qualified, the original safety voltage is determined as the test safety voltage, so as to ensure the objectivity and accuracy of the test safety voltage.

如下表三所示，在对待测IGBT进行双脉冲试验，使得待测IGBT的试验实测电流达到待测电流Ic1,从所有试验实测电压中确定实测最大电压为Vce max1和原始安全电压Vce1，再采用安全电压校验逻辑对原始阈值电压Vce th1、实测最大电压为Vce max1和原始安全电压Vce1进行校验，以将校验合格的原始安全电压Vce1确定为试验安全电压。As shown in Table 3 below, the double-pulse test is performed on the IGBT to be tested, so that the actual measured current of the IGBT to be tested reaches the current Ic1 to be measured. The safety voltage verification logic verifies the original threshold voltage Vce th1, the measured maximum voltage Vce max1 and the original safety voltage Vce1, so as to determine the original safety voltage Vce1 that has passed the verification as the test safety voltage.

表三数据记录表(二)Table 3 Data Record Table (2)

电流Ic(A)Current Ic(A)	Vce th(V)Vce th(V)	Vce max(V)(记录)Vce max(V) (record)	Vce(V)(记录)Vce(V) (record)
Ic1(例840)Ic1 (Example 840)	Vce th1Vce th1	Vce max1Vce max1	Vce1Vce1
Ic2(例800)Ic2 (Example 800)	Vce th2Vce th2	Vce max2Vce max2	Vce2Vce2
Ic3(例700)Ic3 (Example 700)	Vce th3Vce th3	Vce max3Vce max3	Vce3Vce3
Ic4(例600)Ic4 (Example 600)	Vce th4Vce th4	Vce max4Vce max4	Vce4Vce4
Ic5(例500)Ic5 (Example 500)	Vce th5Vce th5	Vce max5Vce max5	Vce5Vce5
Ic6(例400)Ic6 (Example 400)	Vce th6Vce th6	Vce max6Vce max6	Vce6Vce6
Ic7(例300)Ic7 (Example 300)	Vce th7Vce th7	Vce max7Vce max7	Vce7Vce7
Ic8(例200)Ic8 (Example 200)	Vce th8Vce th8	Vce max8Vce max8	Vce8Vce8
Ic9(例100)Ic9 (Example 100)	Vce th9Vce th9	Vce max9Vce max9	Vce9Vce9

本实施例所提供的IGBT双脉冲试验方法中，根据待测电流对应的试验实测电压，确定其对应的实测最大电压和原始安全电压，保证实测最大电压和原始安全电压的客观性。再基于待测电流对应的原始阈值电压、实测最大电压和原始安全电压，获取待测电流对应的试验安全电压，从而保障试验安全电压获取的准确性和客观性。In the IGBT double-pulse test method provided in this embodiment, the corresponding measured maximum voltage and the original safe voltage are determined according to the actual measured voltage of the test corresponding to the current to be measured, so as to ensure the objectivity of the measured maximum voltage and the original safe voltage. Then, based on the original threshold voltage, the measured maximum voltage and the original safe voltage corresponding to the current to be measured, the test safety voltage corresponding to the current to be measured is obtained, thereby ensuring the accuracy and objectivity of the test safety voltage acquisition.

作为一示例，如图6所示，步骤S402，即基于待测电流对应的原始阈值电压和试验实测电压，获取待测电流对应的试验安全电压，包括如下步骤：As an example, as shown in FIG. 6, step S402, that is, obtaining the test safety voltage corresponding to the current to be measured based on the original threshold voltage corresponding to the current to be measured and the actual measured voltage of the test, including the following steps:

S601：将待测电流对应的试验实测电压中第二个尖峰电压，确定为待测电流对应的实测最大电压。S601: Determine the second peak voltage in the experimentally measured voltage corresponding to the current to be measured as the measured maximum voltage corresponding to the current to be measured.

由于双脉冲试验过程中，待测IGBT基于脉冲驱动器的双脉冲驱动信号，需进行两次关断，每次关断瞬间，由于杂散电感的存在会形成一个尖峰电压，该尖峰电压比其关断前后的试验实测电压大.一般来说，待测IGBT第二次关断时形成的尖峰电压大于第一次关断时形成的尖峰电压大，因此，试验控制器可以将待测电流对应的试验实测电压中第二个尖峰电压，确定为待测电流对应的实测最大电压，如图11中圆形框中的试验实测电压。During the double-pulse test, the IGBT to be tested needs to be turned off twice based on the double-pulse driving signal of the pulse driver. At the moment of each turn-off, a peak voltage will be formed due to the existence of stray inductance, and the peak voltage will be higher than its off-state. The measured voltage before and after the test is large. Generally speaking, the peak voltage formed when the IGBT to be tested is turned off for the second time is larger than the peak voltage formed when the IGBT is turned off for the first time. Therefore, the test controller can The second peak voltage in the measured voltage of the test is determined as the measured maximum voltage corresponding to the current to be measured, such as the measured voltage of the test in the circle box in Figure 11.

S602：将待测电流对应的实测最大电压之后的试验实测电压中，若当前时刻的试验实测电压与上一时刻的试验实测电压相同，则将当前时刻的试验实测电压确定为原始安全电压。S602: In the test voltage after the measured maximum voltage corresponding to the current to be measured, if the test voltage at the current moment is the same as the test voltage at the previous moment, the test voltage at the current moment is determined as the original safe voltage.

本示例中，试验控制器在确定待测电流对应的实测最大电压之后，从实测最大电压之后的所有试验实测电压中，将当前时刻的试验实测电压与上一时刻的试验实测电压相比，若当前时刻的试验实测电压与上一时刻的试验实测电压，则可将当前时刻的试验实测电压确定为待测IGBT对应的原始安全电压。一般来说，在待测IGBT正常工作时，在第二个尖峰电压(即实测最大电压)之后，其待测电压会形成下降阶段和平缓阶段，在下降阶段，当前时刻的试验实测电压小于上一时刻的试验实测电压；在平缓阶段，当前时刻的试验实测电压等于上一时刻的试验实测电压。因此，将当前时刻的试验实测电压与上一时刻的试验实测电压相比，若当前时刻的试验实测电压与上一时刻的试验实测电压相同，则说明进入平缓阶段，其试验实测电压不再发生变化，说明此时待测IGBT已经正常工作，因此，可将当前时刻的试验实测电压确定为原始安全电压。In this example, after determining the measured maximum voltage corresponding to the current to be measured, the test controller compares the test voltage at the current moment with the test voltage at the previous moment from all the test voltages after the measured maximum voltage. If The test voltage at the current moment and the test voltage at the previous moment can be determined as the original safe voltage corresponding to the IGBT to be tested. Generally speaking, when the IGBT to be tested is working normally, after the second peak voltage (that is, the measured maximum voltage), the voltage to be measured will form a falling stage and a gentle stage. The measured voltage of the test at one moment; in the flat stage, the measured voltage of the test at the current moment is equal to the measured voltage of the test at the previous moment. Therefore, compare the test voltage at the current moment with the test voltage at the previous moment. If the test voltage at the current moment is the same as the test voltage at the previous moment, it means that it has entered a flat stage, and the test voltage no longer occurs. changes, indicating that the IGBT to be tested has been working normally at this time. Therefore, the test voltage at the current moment can be determined as the original safe voltage.

S603：基于待测电流对应的原始阈值电压、实测最大电压和原始安全电压，获取待测电流对应的试验安全电压。S603: Obtain a test safety voltage corresponding to the current to be measured based on the original threshold voltage, the measured maximum voltage, and the original safe voltage corresponding to the current to be measured.

其中，步骤601是步骤S501的一具体实施方式，步骤S602是步骤S502的一具体实施方式，步骤S603与步骤S503相同，此处不一一赘述。Wherein, step 601 is a specific implementation of step S501, step S602 is a specific implementation of step S502, and step S603 is the same as step S503, and will not be repeated here.

在一实施例中，如图7所示，步骤S503，即基于待测电流对应的原始阈值电压、实测最大电压和原始安全电压，获取待测电流对应的试验安全电压，包括如下步骤：In one embodiment, as shown in FIG. 7 , step S503, that is, obtaining the test safety voltage corresponding to the current to be measured based on the original threshold voltage, the measured maximum voltage and the original safe voltage corresponding to the current to be measured, including the following steps:

S701：获取实测最大电压与原始阈值电压的试验电压差值，判断试验电压差值是否小于预设电压差值。S701: Obtain a test voltage difference between the measured maximum voltage and the original threshold voltage, and determine whether the test voltage difference is smaller than a preset voltage difference.

S702：若试验电压差值小于预设电压差值，则将原始安全电压确定为待测电流对应的试验安全电压。S702: If the test voltage difference is less than the preset voltage difference, determine the original safety voltage as the test safety voltage corresponding to the current to be measured.

其中，试验电压差值是指实测最大电压和原始阈值电压两个电压的差值。预设电压差值是预先设置的用于评估实测最大电压和原始阈值电压是否接近的阈值。Among them, the test voltage difference refers to the difference between the measured maximum voltage and the original threshold voltage. The preset voltage difference is a preset threshold for evaluating whether the measured maximum voltage is close to the original threshold voltage.

作为一示例，试验控制器在获取实测最大电压和原始阈值电压之后，基于实测最大电压和原始阈值电压计算试验电压差值，再将试验电压差值与预设电压差值进行比较；若试验电压差值小于预设电压差值，说明实测最大电压接近于原始阈值电压，可以保障待测IGBT在关断瞬间所形成的尖峰电压接近于原始阈值电压，可以保障待测IGBT正常工作，此时，可以将原始安全电压确定为待测电流对应的试验安全电压，有助于保障获取的试验安全电压的准确性和客观性。As an example, after obtaining the measured maximum voltage and the original threshold voltage, the test controller calculates the test voltage difference based on the measured maximum voltage and the original threshold voltage, and then compares the test voltage difference with the preset voltage difference; if the test voltage The difference is less than the preset voltage difference, indicating that the measured maximum voltage is close to the original threshold voltage, which can ensure that the peak voltage formed by the IGBT to be tested at the moment of turn-off is close to the original threshold voltage, which can ensure the normal operation of the IGBT to be tested. The original safety voltage can be determined as the test safety voltage corresponding to the current to be measured, which helps to ensure the accuracy and objectivity of the obtained test safety voltage.

S703：若试验电压差值不小于预设电压差值，则提高电源电压并降低脉冲宽度，对待测IGBT进行双脉冲试验，使待测IGBT的试验实测电流维持在待测电流，获取待测电流对应的试验实测电压，重复执行基于待测电流对应的原始阈值电压和试验实测电压，获取待测电流对应的试验安全电压。S703: If the test voltage difference is not less than the preset voltage difference, increase the power supply voltage and reduce the pulse width, perform a double-pulse test on the IGBT to be tested, so that the tested current of the IGBT to be tested is maintained at the current to be tested, and the current to be tested is obtained For the corresponding test voltage, the original threshold voltage corresponding to the test current and the test test voltage are repeatedly performed to obtain the test safety voltage corresponding to the test current.

作为另一示例，试验控制器在获取实测最大电压和原始阈值电压之后，基于实测最大电压和原始阈值电压计算试验电压差值，再将试验电压差值与预设电压差值进行比较；若试验电压差值不小于预设电压差值，说明实测最大电压不接近于原始阈值电压，说明待测IGBT在关断瞬间所形成的尖峰电压远高于原始阈值电压，会导致待测IGBT损坏的风险较大，因此，需提高电源电压并降低脉冲宽度，对待测IGBT进行双脉冲试验，使待测IGBT的试验实测电流维持在待测电流，获取待测电流对应的试验实测电压，即重复执行步骤S402。可以理解地，在试验电压差值不小于预设电压差值，提高电源电压并降低脉冲宽度，再次对待测IGBT进行双脉冲试验，直至确定待测电流对应的试验安全电压，有助于保障获取的试验安全电压的准确性和客观性。As another example, after obtaining the measured maximum voltage and the original threshold voltage, the test controller calculates the test voltage difference based on the measured maximum voltage and the original threshold voltage, and then compares the test voltage difference with the preset voltage difference; if the test The voltage difference is not less than the preset voltage difference, indicating that the measured maximum voltage is not close to the original threshold voltage, indicating that the peak voltage formed by the IGBT to be tested at the moment of turn-off is much higher than the original threshold voltage, which will lead to the risk of damage to the IGBT to be tested. Therefore, it is necessary to increase the power supply voltage and reduce the pulse width, conduct a double-pulse test on the IGBT to be tested, so that the actual measured current of the IGBT to be tested is maintained at the current to be measured, and obtain the actual measured voltage of the test corresponding to the current to be measured, that is, repeat the steps. S402. Understandably, when the test voltage difference is not less than the preset voltage difference, increase the power supply voltage and reduce the pulse width, and perform a double-pulse test on the IGBT to be tested again until the test safety voltage corresponding to the current to be tested is determined, which helps to ensure the acquisition of The accuracy and objectivity of the test safety voltage.

在一实施例中，提供一种IGBT控制方法，以该IGBT控制方法应用在电动汽车逆变器为例，该电动汽车逆变器包括目标IGBT和与目标IGBT相连的逆变器控制器，如图8所示，该IGBT控制方法包括如下步骤：In one embodiment, an IGBT control method is provided. Taking the IGBT control method applied to an electric vehicle inverter as an example, the electric vehicle inverter includes a target IGBT and an inverter controller connected to the target IGBT, such as As shown in FIG. 8, the IGBT control method includes the following steps:

S801：实时采集目标IGBT的当前实测电流和当前实测电压。S801: Collect the current measured current and current measured voltage of the target IGBT in real time.

其中，目标IGBT是设置在电动汽车逆变器中的IGBT，具体是指由逆变器控制器控制工作的IGBT。当前实测电流是实时采集目标IGBT工作过程中的电流，可以通过电动汽车逆变器内置的采样电路采集。当前实测电压是实时采集目标IGBT工作过程中集电极与发射极之间的电压，可以通过电动汽车逆变器内置的采样电路采集。Wherein, the target IGBT is an IGBT arranged in the inverter of the electric vehicle, and specifically refers to an IGBT whose operation is controlled by the inverter controller. The current measured current is the current collected in real time during the working process of the target IGBT, which can be collected through the built-in sampling circuit of the electric vehicle inverter. The current measured voltage is the real-time acquisition of the voltage between the collector and the emitter during the working process of the target IGBT, which can be acquired through the built-in sampling circuit of the electric vehicle inverter.

本示例中，在电动汽车逆变器工作过程中，采样电路实时采集目标IGBT的当前实测电流和当前实测电压，采样电路将所采集到的当前实测电流和当前实测电压发送给逆变器控制器，以使逆变器控制器获取目标IGBT的当前实测电流和当前实测电压。In this example, during the working process of the electric vehicle inverter, the sampling circuit collects the current measured current and current measured voltage of the target IGBT in real time, and the sampling circuit sends the collected current measured current and current measured voltage to the inverter controller. , so that the inverter controller obtains the current measured current and current measured voltage of the target IGBT.

S802：将与目标IGBT型号相同的待测IGBT对应的验证SOA曲线，确定为目标SOA曲线。S802: Determine the verification SOA curve corresponding to the to-be-tested IGBT of the same type as the target IGBT as the target SOA curve.

其中，目标SOA曲线是用于控制目标IGBT安全工作的曲线。Among them, the target SOA curve is a curve used to control the safe operation of the target IGBT.

在步骤S801之前，用户可以预先将通过上述实施例确定的待测IGBT对应的验证SOA曲线存储到逆变器控制器对应的存储器中，该验证SOA曲线可以是至少一种型号的待测IGBT对应的验证SOA曲线，经过足够的试验数据支撑，具有客观性和准确性。Before step S801, the user may store in advance the verification SOA curve corresponding to the IGBT to be tested determined by the above-mentioned embodiment in the memory corresponding to the inverter controller, and the verification SOA curve may be corresponding to at least one type of IGBT to be tested The verification SOA curve, supported by sufficient test data, is objective and accurate.

本示例中，逆变器控制器根据其需要控制的所有目标IGBT的型号，查询存储器，将与目标IGBT型号相同的待测IGBT对应的验证SOA曲线，确定为需要控制目标IGBT安全工作的目标SOA曲线。该目标SOA曲线是基于与目标IGBT型号相同的待测IGBT进行双脉冲试验，所确定的该型号IGBT的反向偏置安全工作区所形成的曲线。In this example, the inverter controller queries the memory according to the models of all target IGBTs it needs to control, and determines the verification SOA curve corresponding to the IGBT to be tested with the same model as the target IGBT as the target SOA that needs to control the safe operation of the target IGBT curve. The target SOA curve is a curve formed based on the double-pulse test of the IGBT to be tested with the same type as the target IGBT, and the reverse bias safe working area of the IGBT of this type is determined.

S803：基于当前实测电流和目标SOA曲线，确定当前实测电流对应的目标阈值电压，或者，基于当前实测电压和目标SOA曲线，确定当前实测电压对应的目标阈值电流。S803: Determine the target threshold voltage corresponding to the current measured current based on the current measured current and the target SOA curve, or determine the target threshold current corresponding to the currently measured voltage based on the current measured voltage and the target SOA curve.

其中，目标阈值电压是指在目标SOA曲线中与当前实测电流相对应的电压。作为一示例，逆变器控制器基于当前实测电流，采用数据读取工具从目标SOA曲线中读取与当前实测电流相对应的电压，将该电压确定为当前实测电流相对应的目标阈值电压。The target threshold voltage refers to the voltage corresponding to the current measured current in the target SOA curve. As an example, based on the current measured current, the inverter controller uses a data reading tool to read the voltage corresponding to the current measured current from the target SOA curve, and determines the voltage as the target threshold voltage corresponding to the currently measured current.

其中，目标阈值电流是指在目标SOA曲线中与当前实测电压相对应的电流。作为一示例，逆变器控制器基于当前实测电压，采用数据读取工具从目标SOA曲线中读取与当前实测电压相对应的电流，将该电流确定为当前实测电压相对应的目标阈值电流。The target threshold current refers to the current corresponding to the currently measured voltage in the target SOA curve. As an example, the inverter controller uses a data reading tool to read the current corresponding to the current measured voltage from the target SOA curve based on the currently measured voltage, and determines the current as the target threshold current corresponding to the currently measured voltage.

S803：若当前实测电压大于当前实测电流对应的目标阈值电压，或者当前实测电流大于当前实测电压对应的目标阈值电流，则执行线性降电流策略，降低目标IGBT的输出电流。S803: If the current measured voltage is greater than the target threshold voltage corresponding to the current measured current, or the current measured current is greater than the target threshold current corresponding to the current measured voltage, execute a linear current reduction strategy to reduce the output current of the target IGBT.

其中，线性降电流策略是用于实现线性降低输出电流的控制策略。Among them, the linear current reduction strategy is a control strategy for realizing linear reduction of the output current.

作为一示例，逆变器控制器将从目标SOA曲线中读取的目标阈值电压与当前实测电压进行比较，若当前实测电压大于当前实测电流对应的目标阈值电压，则说明当前实测电压较大，在目标IGBT关断时产生的尖峰电压可能损坏目标IGBT，因此，在目标IGBT关断瞬间，需执行线性降电流策略，以将目标IGBT的当前实测电流线性降低至0，既可以保障充分利用目标IGBT的安全工作区，使得目标IGBT的工作区间较大，充分发挥目标IGBT的输出能力，又可避免将目标IGBT的输出电流直接从当前实测电流直接降低至0，保证输出电流调节的平缓性。As an example, the inverter controller compares the target threshold voltage read from the target SOA curve with the current measured voltage. If the current measured voltage is greater than the target threshold voltage corresponding to the currently measured current, it means that the current measured voltage is larger. The peak voltage generated when the target IGBT is turned off may damage the target IGBT. Therefore, at the moment when the target IGBT is turned off, a linear current reduction strategy needs to be implemented to linearly reduce the current measured current of the target IGBT to 0, which can ensure that the target IGBT is fully utilized. The safe working area of the IGBT makes the working range of the target IGBT larger, gives full play to the output capability of the target IGBT, and avoids directly reducing the output current of the target IGBT from the current measured current to 0, ensuring the smoothness of the output current regulation.

作为另一示例，逆变器控制器将从目标SOA曲线中读取的目标阈值电流与当前实测电流进行比较，若当前实测电流大于当前实测电压对应的目标阈值电流，则说明当前实测电流较大，在目标IGBT关断时产生的尖峰电压可能损坏目标IGBT，因此，在目标IGBT关断瞬间，需执行线性降电流策略，以将目标IGBT的当前实测电流线性降低至0，既可以保障充分利用目标IGBT的安全工作区，使得目标IGBT的工作区间较大，充分发挥目标IGBT的输出能力，又可避免将目标IGBT的输出电流直接从当前实测电流直接降低至0，保证输出电流调节的平缓性。As another example, the inverter controller compares the target threshold current read from the target SOA curve with the current measured current. If the current measured current is greater than the target threshold current corresponding to the current measured voltage, it means that the current measured current is larger , the peak voltage generated when the target IGBT is turned off may damage the target IGBT. Therefore, at the moment when the target IGBT is turned off, a linear current reduction strategy needs to be implemented to linearly reduce the current measured current of the target IGBT to 0, which can ensure full utilization. The safe working area of the target IGBT makes the working range of the target IGBT larger, fully exerts the output capability of the target IGBT, and avoids directly reducing the output current of the target IGBT from the current measured current to 0, ensuring the smoothness of the output current regulation. .

本实施例所提供的IGBT控制方法，利用当前实测电流查询目标SOA曲线，确定当前实测电流对应的目标阈值电压，或者利用当前实测电压查询目标SOA曲线，确定当前实测电压对应的目标阈值电流；并在当前实测电压大于当前实测电流对应的目标阈值电压或者当前实测电流大于当前实测电压对应的目标阈值电流时，执行线性降电流策略，降低目标IGBT的输出电流，可避免目标IGBT关断瞬间产生的尖峰电压损坏目标IGBT，并充分利用目标IGBT的安全工作区，使得目标IGBT的工作区间较大，充分发挥目标IGBT的输出能力，而且可以保证输出电流调节的平缓性。The IGBT control method provided in this embodiment uses the current measured current to query the target SOA curve to determine the target threshold voltage corresponding to the current measured current, or uses the current measured voltage to query the target SOA curve to determine the current measured voltage. The corresponding target threshold current; and When the current measured voltage is greater than the target threshold voltage corresponding to the current measured current or the current measured current is greater than the target threshold current corresponding to the current measured voltage, a linear current reduction strategy is implemented to reduce the output current of the target IGBT, which can avoid the instantaneous turn-off of the target IGBT. The peak voltage damages the target IGBT, and makes full use of the safe working area of the target IGBT, making the working range of the target IGBT larger, giving full play to the output capability of the target IGBT, and ensuring the smoothness of the output current regulation.

应理解，上述实施例中各步骤的序号的大小并不意味着执行顺序的先后，各过程的执行顺序应以其功能和内在逻辑确定，而不应对本申请实施例的实施过程构成任何限定。It should be understood that the size of the sequence numbers of the steps in the above embodiments does not mean the sequence of execution, and the execution sequence of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

在一个实施例中，提供一种IGBT双脉冲试验***，IGBT双脉冲试验***包括试验控制器、与试验控制器相连的示波器和脉冲驱动器，示波器和脉冲驱动器均与待测IGBT相连，试验控制器包括存储器、处理器以及存储在存储器中并可在处理器上运行的计算机可读指令，处理器执行计算机可读指令时实现如上述实施例中的IGBT双脉冲试验方法，如图2所示的步骤S201-S203，或者图3-图7所示，为避免重复，这里不再赘述。In one embodiment, an IGBT double-pulse test system is provided. The IGBT double-pulse test system includes a test controller, an oscilloscope and a pulse driver connected to the test controller. Both the oscilloscope and the pulse driver are connected to the IGBT to be tested, and the test controller It includes a memory, a processor, and computer-readable instructions stored in the memory and can be run on the processor. When the processor executes the computer-readable instructions, the IGBT double-pulse test method in the above-mentioned embodiment is implemented, as shown in FIG. 2 . Steps S201-S203, or as shown in FIG. 3-FIG. 7, are not repeated here in order to avoid repetition.

本申请实施例提供一种逆变器控制器，与电动汽车逆变器的目标IGBT相连，包括存储器、处理器以及存储在存储器中并可在处理器上运行的计算机可读指令，处理器执行计算机可读指令时实现如上述实施例中的IGBT控制方法，如图8所示的步骤S801-S804，为避免重复，这里不再赘述。Embodiments of the present application provide an inverter controller, which is connected to a target IGBT of an electric vehicle inverter, and includes a memory, a processor, and computer-readable instructions stored in the memory and executable on the processor. The processor executes The computer-readable instructions implement the IGBT control method in the above-mentioned embodiment, such as steps S801-S804 shown in FIG. 8 , and in order to avoid repetition, details are not repeated here.

本领域普通技术人员可以理解实现上述实施例方法中的全部或部分流程，是可以通过计算机可读指令来指令相关的硬件来完成，所述的计算机可读指令可存储于一非易失性计算机可读取存储介质中，该计算机可读指令在执行时，可包括如上述各方法的实施例的流程。其中，本申请所提供的各实施例中所使用的对存储器、存储、数据库或其它介质的任何引用，均可包括非易失性和/或易失性存储器。非易失性存储器可包括只读存储器(ROM)、可编程ROM(PROM)、电可编程ROM(EPROM)、电可擦除可编程ROM(EEPROM)或闪存。易失性存储器可包括随机存取存储器(RAM)或者外部高速缓冲存储器。作为说明而非局限，RAM以多种形式可得，诸如静态RAM(SRAM)、动态RAM(DRAM)、同步DRAM(SDRAM)、双数据率SDRAM(DDRSDRAM)、增强型SDRAM(ESDRAM)、同步链路(Synchlink)DRAM(SLDRAM)、存储器总线(Rambus)直接RAM(RDRAM)、直接存储器总线动态RAM(DRDRAM)、以及存储器总线动态RAM(RDRAM)等。Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be implemented by instructing relevant hardware through computer-readable instructions, and the computer-readable instructions can be stored in a non-volatile computer. In the readable storage medium, the computer-readable instructions, when executed, may include the processes of the foregoing method embodiments. Wherein, any reference to memory, storage, database or other medium used in the various embodiments provided in this application may include non-volatile and/or volatile memory. Nonvolatile memory may include read only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous chain Road (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

所属领域的技术人员可以清楚地了解到，为了描述的方便和简洁，仅以上述各功能单元、模块的划分进行举例说明，实际应用中，可以根据需要而将上述功能分配由不同的功能单元、模块完成，即将所述装置的内部结构划分成不同的功能单元或模块，以完成以上描述的全部或者部分功能。Those skilled in the art can clearly understand that, for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example. Module completion, that is, dividing the internal structure of the device into different functional units or modules to complete all or part of the functions described above.

以上实施例仅用以说明本申请的技术方案，而非对其限制；尽管参照前述实施例对本申请进行了详细的说明，本领域的普通技术人员应当理解：其依然可以对前述各实施例所记载的技术方案进行修改，或者对其中部分技术特征进行等同替换；而这些修改或者替换，并不使相应技术方案的本质脱离本申请各实施例技术方案的精神和范围，均应包含在本申请的保护范围之内。The above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The recorded technical solutions are modified, or some technical features thereof are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the application, and should be included in the application. within the scope of protection.

Claims

一种IGBT双脉冲试验方法，其中，包括：An IGBT double-pulse test method, comprising:

从原始SOA曲线中获取待验证数据，所述待验证数据包括待测电流和与所述待测电流相对应的原始阈值电压；Obtain the data to be verified from the original SOA curve, the data to be verified includes the current to be measured and the original threshold voltage corresponding to the current to be measured;

基于所述待测电流和所述原始阈值电压，对待测IGBT进行双脉冲试验，获取与所述待测电流相对应的试验安全电压；Based on the current to be tested and the original threshold voltage, a double-pulse test is performed on the IGBT to be tested to obtain a test safety voltage corresponding to the current to be tested;

基于所述待测电流和所述试验安全电压，构建与所述待测IGBT相对应的验证SOA曲线。Based on the current to be tested and the test safety voltage, a verification SOA curve corresponding to the IGBT to be tested is constructed.
如权利要求1所述的IGBT双脉冲试验方法，其中，所述从原始SOA曲线中获取待验证数据，包括：The IGBT double-pulse test method according to claim 1, wherein the obtaining the data to be verified from the original SOA curve comprises:

获取数据选取任务，所述数据选取任务包括起始数值，还包括选取数量或者选取步长；Obtaining a data selection task, the data selection task includes an initial value, and also includes a selection quantity or a selection step;

采用数据读取工具执行所述数据选取任务，基于所述起始数值和所述选取数量从所述原始SOA曲线中获取待验证数据，或者，基于所述起始数值和所述选取步长从所述原始SOA曲线中获取待验证数据。A data reading tool is used to perform the data selection task, and the data to be verified is obtained from the original SOA curve based on the initial value and the selection quantity, or, based on the initial value and the selection step size from The data to be verified is obtained from the original SOA curve.
如权利要求1所述的IGBT双脉冲试验方法，其中，所述基于所述待测电流和所述原始阈值电压，对待测IGBT进行双脉冲试验，获取与所述待测电流相对应的试验安全电压，包括：The IGBT double-pulse test method according to claim 1, wherein, based on the to-be-measured current and the original threshold voltage, the to-be-measured IGBT is subjected to a double-pulse test to obtain a test safety corresponding to the to-be-measured current voltage, including:

调整电源电压和脉冲宽度，对待测IGBT进行双脉冲试验，使所述待测IGBT的试验实测电流达到所述待测电流，获取所述待测电流对应的试验实测电压；Adjust the power supply voltage and pulse width, perform a double-pulse test on the IGBT to be tested, so that the actual measured current of the IGBT to be tested reaches the current to be measured, and obtain the actual measured voltage of the test corresponding to the current to be measured;

基于所述待测电流对应的所述原始阈值电压和所述试验实测电压，获取所述待测电流对应的试验安全电压。Based on the original threshold voltage corresponding to the to-be-measured current and the experimentally measured voltage, the experimental safety voltage corresponding to the to-be-measured current is obtained.
如权利要求3所述的IGBT双脉冲试验方法，其中，所述基于所述待测电流对应的所述原始阈值电压和所述试验实测电压，获取所述待测电流对应的试验安全电压，包括：The IGBT double-pulse test method according to claim 3, wherein the obtaining the test safety voltage corresponding to the current to be measured based on the original threshold voltage corresponding to the current to be measured and the actual measured voltage of the test, comprising: :

基于所述待测电流对应的试验实测电压，确定所述待测电流对应的实测最大电压；Determine the measured maximum voltage corresponding to the to-be-measured current based on the test-measured voltage corresponding to the to-be-measured current;

基于所述待测电流对应的实测最大电压，获取所述待测电流对应的原始安全电压；Based on the measured maximum voltage corresponding to the current to be measured, obtain the original safe voltage corresponding to the current to be measured;

基于所述待测电流对应的所述原始阈值电压、所述实测最大电压和所述原始安全电压，获取所述待测电流对应的试验安全电压。Based on the original threshold voltage, the measured maximum voltage, and the original safety voltage corresponding to the current to be measured, a test safety voltage corresponding to the current to be measured is obtained.
如权利要求4所述的IGBT双脉冲试验方法，其中，所述基于所述待测电流对应的试验实测电压，确定所述待测电流对应的实测最大电压，包括：The IGBT double-pulse test method according to claim 4, wherein determining the measured maximum voltage corresponding to the to-be-measured current based on the experimentally measured voltage corresponding to the to-be-measured current comprises:

将所述待测电流对应的试验实测电压中第二个尖峰电压，确定为待测电流对应的实测最大电压；Determine the second peak voltage in the experimental measured voltage corresponding to the to-be-measured current as the measured maximum voltage corresponding to the to-be-measured current;

所述基于所述待测电流对应的实测最大电压，获取所述待测电流对应的原始安全电压，包括：Obtaining the original safe voltage corresponding to the current to be measured based on the measured maximum voltage corresponding to the current to be measured includes:

将所述待测电流对应的实测最大电压之后的试验实测电压中，若当前时刻的试验实测电压与上一时刻的试验实测电压相同，则将当前时刻的试验实测电压确定为所述原始安全电压。In the test voltage after the measured maximum voltage corresponding to the current to be measured, if the test voltage at the current moment is the same as the test voltage at the previous moment, the test voltage at the current moment is determined as the original safety voltage. .
如权利要求4所述的IGBT双脉冲试验方法，其中，所述基于所述待测电流对应的所述原始阈值电压、所述实测最大电压和所述原始安全电压，获取所述待测电流对应的试验安全电压，包括：The IGBT double-pulse test method according to claim 4, wherein, based on the original threshold voltage, the measured maximum voltage and the original safe voltage corresponding to the to-be-measured current, obtaining the corresponding to the to-be-measured current The test safety voltage, including:

获取所述实测最大电压与所述原始阈值电压的试验电压差值，判断所述试验电压差值是否小于预设电压差值；Obtain the test voltage difference between the measured maximum voltage and the original threshold voltage, and determine whether the test voltage difference is less than a preset voltage difference;

若所述试验电压差值小于所述预设电压差值，则将所述原始安全电压确定为所述待测电流对应的试验安全电压。If the test voltage difference is smaller than the preset voltage difference, the original safe voltage is determined as the test safe voltage corresponding to the current to be measured.
如权利要求6所述的IGBT双脉冲试验方法，其中，在所述判断所述试验电压差值是否小于预设电压差值之后，所述IGBT双脉冲试验方法还包括：The IGBT double-pulse test method according to claim 6, wherein, after said judging whether the test voltage difference is less than a preset voltage difference, the IGBT double-pulse test method further comprises:

若所述试验电压差值不小于所述预设电压差值，则提高所述电源电压并降低脉冲宽度，对待测IGBT进行双脉冲试验，使所述待测IGBT的试验实测电流维持在所述待测电流，获取所述待测电流对应的试验实测电压，重复执行所述基于所述待测电流对应的所述原始阈值电压和所述试验实测电压，获取所述待测电流对应的试验安全电压。If the test voltage difference is not less than the preset voltage difference, increase the power supply voltage and reduce the pulse width, and perform a double-pulse test on the IGBT to be tested, so that the test current of the IGBT to be tested is maintained at the The current to be measured, the actual measured voltage of the test corresponding to the current to be measured is obtained, the original threshold voltage corresponding to the current to be measured and the measured voltage of the test are repeatedly performed, and the test safety corresponding to the current to be measured is obtained. Voltage.
一种IGBT双脉冲试验***，所述IGBT双脉冲试验***包括试验控制器、与所述试验控制器相连的示波器和脉冲驱动器，所述示波器和所述脉冲驱动器均与待测IGBT相连，所述试验控制器包括存储器、处理器以及存储在所述存储器中并可在所述处理器上运行的计算机可读指令，其中，所述处理器执行所述计算机可读指令时实现如下步骤：An IGBT double-pulse test system, the IGBT double-pulse test system includes a test controller, an oscilloscope and a pulse driver connected to the test controller, the oscilloscope and the pulse driver are both connected to the IGBT to be tested, and the An assay controller includes a memory, a processor, and computer-readable instructions stored in the memory and executable on the processor, wherein the processor, when executing the computer-readable instructions, implements the following steps:

从原始SOA曲线中获取待验证数据，所述待验证数据包括待测电流和与所述待测电流相对应的原始阈值电压；Obtain the data to be verified from the original SOA curve, the data to be verified includes the current to be measured and the original threshold voltage corresponding to the current to be measured;

基于所述待测电流和所述原始阈值电压，对待测IGBT进行双脉冲试验，获取与所述待测电流相对应的试验安全电压；Based on the current to be tested and the original threshold voltage, a double-pulse test is performed on the IGBT to be tested to obtain a test safety voltage corresponding to the current to be tested;

基于所述待测电流和所述试验安全电压，构建与所述待测IGBT相对应的验证SOA曲线。Based on the current to be tested and the test safety voltage, a verification SOA curve corresponding to the IGBT to be tested is constructed.
如权利要求8所述的IGBT双脉冲试验***，其中，所述从原始SOA曲线中获取待验证数据，包括：The IGBT double-pulse test system according to claim 8, wherein the obtaining data to be verified from the original SOA curve comprises:

获取数据选取任务，所述数据选取任务包括起始数值，还包括选取数量或者选取步长；Obtaining a data selection task, the data selection task includes an initial value, and also includes a selection quantity or a selection step;

采用数据读取工具执行所述数据选取任务，基于所述起始数值和所述选取数量从所述原始SOA曲线中获取待验证数据，或者，基于所述起始数值和所述选取步长从所述原始SOA曲线中获取待验证数据。Use a data reading tool to perform the data selection task, and obtain the data to be verified from the original SOA curve based on the initial value and the selection quantity, or, based on the initial value and the selection step size from The data to be verified is obtained from the original SOA curve.
如权利要求8所述的IGBT双脉冲试验***，其中，所述基于所述待测电流和所述原始阈值电压，对待测IGBT进行双脉冲试验，获取与所述待测电流相对应的试验安全电压，包括：The IGBT double-pulse test system according to claim 8, wherein, based on the current to be tested and the original threshold voltage, the double-pulse test of the IGBT to be tested is performed to obtain a test safety corresponding to the current to be tested voltage, including:

调整电源电压和脉冲宽度，对待测IGBT进行双脉冲试验，使所述待测IGBT的试验实测电流达到所述待测电流，获取所述待测电流对应的试验实测电压；Adjust the power supply voltage and pulse width, perform a double-pulse test on the IGBT to be tested, so that the actual measured current of the IGBT to be tested reaches the current to be measured, and obtain the actual measured voltage of the test corresponding to the current to be measured;

基于所述待测电流对应的所述原始阈值电压和所述试验实测电压，获取所述待测电流对应的试验安全电压。Based on the original threshold voltage corresponding to the to-be-measured current and the experimentally measured voltage, the experimental safety voltage corresponding to the to-be-measured current is obtained.
如权利要求10所述的IGBT双脉冲试验***，其中，所述基于所述待测电流对应的所述原始阈值电压和所述试验实测电压，获取所述待测电流对应的试验安全电压，包括：The IGBT double-pulse test system according to claim 10, wherein the obtaining the test safety voltage corresponding to the current to be measured based on the original threshold voltage corresponding to the current to be measured and the actual measured voltage of the test, comprising: :

基于所述待测电流对应的试验实测电压，确定所述待测电流对应的实测最大电压；Determine the measured maximum voltage corresponding to the to-be-measured current based on the experimentally measured voltage corresponding to the to-be-measured current;

基于所述待测电流对应的实测最大电压，获取所述待测电流对应的原始安全电压；Based on the measured maximum voltage corresponding to the current to be measured, obtain the original safe voltage corresponding to the current to be measured;

基于所述待测电流对应的所述原始阈值电压、所述实测最大电压和所述原始安全电压，获取所述待测电流对应的试验安全电压。Based on the original threshold voltage, the measured maximum voltage, and the original safety voltage corresponding to the current to be measured, a test safety voltage corresponding to the current to be measured is obtained.
如权利要求11所述的IGBT双脉冲试验***，其中，所述基于所述待测电流对应的试验实测电压，确定所述待测电流对应的实测最大电压，包括：The IGBT double-pulse test system according to claim 11, wherein determining the measured maximum voltage corresponding to the to-be-measured current based on the experimentally-measured voltage corresponding to the to-be-measured current comprises:

将所述待测电流对应的试验实测电压中第二个尖峰电压，确定为待测电流对应的实测最大电压；Determine the second peak voltage in the experimental measured voltage corresponding to the to-be-measured current as the measured maximum voltage corresponding to the to-be-measured current;

所述基于所述待测电流对应的实测最大电压，获取所述待测电流对应的原始安全电压，包括：Obtaining the original safe voltage corresponding to the current to be measured based on the measured maximum voltage corresponding to the current to be measured includes:

将所述待测电流对应的实测最大电压之后的试验实测电压中，若当前时刻的试验实测电压与上一时刻的试验实测电压相同，则将当前时刻的试验实测电压确定为所述原始安全电压。In the test voltage after the measured maximum voltage corresponding to the current to be measured, if the test voltage at the current moment is the same as the test voltage at the previous moment, then the test voltage at the current moment is determined as the original safety voltage. .
如权利要求11所述的IGBT双脉冲试验***，其中，所述基于所述待测电流对应的所述原始阈值电压、所述实测最大电压和所述原始安全电压，获取所述待测电流对应的试验安全电压，包括：The IGBT double-pulse test system according to claim 11 , wherein, based on the original threshold voltage, the measured maximum voltage and the original safe voltage corresponding to the to-be-measured current, the corresponding to the to-be-measured current is obtained. The test safety voltage, including:

获取所述实测最大电压与所述原始阈值电压的试验电压差值，判断所述试验电压差值是否小于预设电压差值；Obtain the test voltage difference between the measured maximum voltage and the original threshold voltage, and determine whether the test voltage difference is less than a preset voltage difference;

若所述试验电压差值小于所述预设电压差值，则将所述原始安全电压确定为所述待测电流对应的试验安全电压。If the test voltage difference is smaller than the preset voltage difference, the original safe voltage is determined as the test safe voltage corresponding to the current to be measured.
如权利要求13所述的IGBT双脉冲试验***，其中，在所述判断所述试验电压差值是否小于预设电压差值之后，所述IGBT双脉冲试验***还包括：The IGBT double-pulse test system according to claim 13, wherein, after judging whether the test voltage difference is less than a preset voltage difference, the IGBT double-pulse test system further comprises:

若所述试验电压差值不小于所述预设电压差值，则提高所述电源电压并降低脉冲宽度，对待测IGBT进行双脉冲试验，使所述待测IGBT的试验实测电流维持在所述待测电流，获取所述待测电流对应的试验实测电压，重复执行所述基于所述待测电流对应的所述原始阈值电压和所述试验实测电压，获取所述待测电流对应的试验安全电压。If the test voltage difference is not less than the preset voltage difference, increase the power supply voltage and reduce the pulse width, and perform a double-pulse test on the IGBT to be tested, so that the test current of the IGBT to be tested is maintained at the The current to be measured, obtain the actual measured voltage of the test corresponding to the current to be measured, repeat the execution based on the original threshold voltage corresponding to the current to be measured and the actual measured voltage of the test, and obtain the test safety corresponding to the current to be measured Voltage.
一种IGBT控制方法，其中，包括：An IGBT control method, comprising:

实时采集目标IGBT的当前实测电流和当前实测电压；Collect the current measured current and current measured voltage of the target IGBT in real time;

将与所述目标IGBT型号相同的待测IGBT对应的验证SOA曲线，确定为目标SOA曲线；The verification SOA curve corresponding to the IGBT to be tested that is the same as the target IGBT model is determined as the target SOA curve;

基于所述当前实测电流和所述目标SOA曲线，确定所述当前实测电流对应的目标阈值电压，或者，基于当前实测电压和目标SOA曲线，确定当前实测电压对应的目标阈值电流；Based on the current measured current and the target SOA curve, determine the target threshold voltage corresponding to the current measured current, or, based on the current measured voltage and the target SOA curve, determine the target threshold current corresponding to the current measured voltage;

若所述当前实测电压大于所述当前实测电流对应的目标阈值电压，或者所述当前实测电流大于所述当前实测电压对应的目标阈值电流，则执行线性降电流策略，降低所述目标IGBT的输出电流。If the current measured voltage is greater than the target threshold voltage corresponding to the current measured current, or the current measured current is greater than the target threshold current corresponding to the current measured voltage, a linear current reduction strategy is executed to reduce the output of the target IGBT current.
一种逆变器控制器，与电动汽车逆变器的目标IGBT相连，包括存储器、处理器以及存储在所述存储器中并可在所述处理器上运行的计算机可读指令，其中，所述处理器执行所述计算机可读指令时实现如下步骤：An inverter controller, connected to a target IGBT of an electric vehicle inverter, includes a memory, a processor, and computer-readable instructions stored in the memory and executable on the processor, wherein the The processor implements the following steps when executing the computer-readable instructions:

实时采集目标IGBT的当前实测电流和当前实测电压；Collect the current measured current and current measured voltage of the target IGBT in real time;

将与所述目标IGBT型号相同的待测IGBT对应的验证SOA曲线，确定为目标SOA曲线；The verification SOA curve corresponding to the IGBT to be tested that is the same as the target IGBT model is determined as the target SOA curve;

基于所述当前实测电流和所述目标SOA曲线，确定所述当前实测电流对应的目标阈值电压，或者，基于当前实测电压和目标SOA曲线，确定当前实测电压对应的目标阈值电流；Based on the current measured current and the target SOA curve, determine the target threshold voltage corresponding to the current measured current, or, based on the current measured voltage and the target SOA curve, determine the target threshold current corresponding to the current measured voltage;

若所述当前实测电压大于所述当前实测电流对应的目标阈值电压，或者所述当前实测电流大于所述当前实测电压对应的目标阈值电流，则执行线性降电流策略，降低所述目标IGBT的输出电流。If the current measured voltage is greater than the target threshold voltage corresponding to the current measured current, or the current measured current is greater than the target threshold current corresponding to the current measured voltage, a linear current reduction strategy is executed to reduce the output of the target IGBT current.