CN115693626A - Overcurrent protection method, operation control device and electric control equipment of power device - Google Patents
Overcurrent protection method, operation control device and electric control equipment of power device Download PDFInfo
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- H—ELECTRICITY
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- H02H9/02—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection responsive to excess current
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Abstract
The invention discloses an overcurrent protection method of a power device, an operation control device, an electric control device and a computer readable storage medium, wherein the method comprises the following steps: acquiring working parameters of the power device within a target duration; determining the average junction temperature of the power device in the target time length according to the working parameters; according to the method, more stable current limiting control can be carried out on the power device, the power device is prevented from being damaged due to overheating to a certain extent, and the running stability of the system is improved.
Description
Technical Field
The invention relates to the field of overcurrent protection of power devices, in particular to an overcurrent protection method, an operation control device and electric control equipment of a power device.
Background
At present, overcurrent protection is usually carried out on a power device according to the current magnitude and the duration, but the influence of external temperature is not considered, the control precision is low, and the current margin of the device is large under the low-temperature condition, so that the problem of excessive protection exists; under the condition of high temperature, devices can operate in an overcurrent mode, and the problem of protection failure exists.
Disclosure of Invention
The present application aims to solve at least one of the technical problems in the prior art, and provides an overcurrent protection method, an operation control device, an electronic control device, and a computer-readable storage medium for a power device, which can perform relatively precise current-limiting control on the power device, and avoid the power device from being damaged due to overheating to a certain extent.
In a first aspect, an embodiment of the present application provides a method for overcurrent protection of a power device, where the method includes: acquiring working parameters of the power device in a target time length; determining the average junction temperature of the power device within the target time length according to the working parameters; and controlling the working state of the power device according to the average junction temperature and the highest allowable junction temperature so as to enable the average junction temperature not to be higher than the highest allowable junction temperature.
According to the embodiment of the first aspect of the present application, an overcurrent protection method for a power device has at least the following beneficial effects: the method comprises the steps of obtaining working parameters of a power device in a target time length so as to obtain the average junction temperature of the power device in the target time length, controlling the working state of the power device according to the average junction temperature and the highest allowed junction temperature of the power device, so that the average junction temperature is not higher than the highest allowed junction temperature, integrating factors such as ambient temperature, heat dissipation conditions, voltage and thermal resistance of the power device, monitoring the average junction temperature of the power device in the target time length by taking the target time length as a period, limiting the working current of the power device, and controlling the power device more stably by taking the target time length as the period, so that the power device can be prevented from being damaged due to overcurrent to a certain extent, and the stability of system operation is improved.
In some embodiments of the present application, the target time duration is a time during which the thermal resistance of the power device tends to stabilize in a thermal resistance model.
In some embodiments of the present application, the controlling the operating state of the power device according to the average junction temperature and the maximum allowable junction temperature includes:
determining a power device conduction current limit value of the power device according to the average junction temperature and the highest allowable junction temperature;
obtaining the required conduction duty ratio of the power device in the next period according to the conduction current limit value of the power device, the current required by the system in the next period and the conduction current of the current actual power device;
and adjusting the conduction duty ratio of the power device according to the required conduction duty ratio of the power device in the next period.
In some embodiments of the present application, the obtaining a required on duty ratio of the power device in the next period according to the limit value of the on current of the power device, the current required by the system in the next period, and the on current of the actual power device includes:
responding to the fact that the power device conducting current limiting value is larger than or equal to the current required by the next period system, taking the current required by the next period system as the current required by the next period power device, and obtaining the conducting duty ratio required by the next period power device according to the current required by the next period power device and the conducting current of the current actual power device;
and in response to the fact that the power device conduction current limit value is smaller than the current required by the next period system, taking the power device conduction current limit value as the current required by the next period power device, and obtaining the conduction duty ratio required by the next period power device according to the current required by the next period power device and the current conduction current of the actual power device.
In some embodiments of the present application, the determining an average junction temperature of the power device over the target time period according to the operating parameter includes: obtaining the average power consumption and the average shell temperature of the power device within the target duration according to the working parameters; determining an average crusting temperature rise according to the average power consumption and the steady-state thermal resistance of the power device; and determining the average junction temperature according to the average shell temperature and the average crusting temperature rise.
In some embodiments of the present application, the operating parameters include an operating voltage, the operating current, and a shell temperature, and the average power consumption is obtained from the operating voltage and the operating current; the average shell temperature is obtained from the shell temperature.
In some embodiments of the present application, the average crusting temperature rise is equal to a product of the average power consumption and the steady-state thermal resistance.
In a second aspect, an embodiment of the present application provides an operation control apparatus, including at least one control processor and a memory, which is used for being connected to the at least one control processor in a communication manner; the memory stores instructions executable by the at least one control processor, and the instructions are executed by the at least one control processor to enable the at least one control processor to execute the method for overcurrent protection of a power device as provided in the embodiment of the first aspect of the present application.
According to the operation control device provided by the embodiment of the second aspect of the application, at least the following advantages are achieved: the method comprises the steps of obtaining working parameters of a power device in a target time length so as to obtain the average junction temperature of the power device in the target time length, controlling the working state of the power device according to the average junction temperature and the highest allowed junction temperature of the power device, so that the average junction temperature is not higher than the highest allowed junction temperature, integrating factors such as ambient temperature, heat dissipation conditions, voltage and thermal resistance of the power device, monitoring the average junction temperature of the power device in the target time length by taking the target time length as a period, limiting the working current of the power device, and controlling the power device more stably by taking the target time length as the period, so that the power device can be prevented from being damaged due to overcurrent to a certain extent, and the stability of system operation is improved.
In a third aspect, an embodiment of the present application provides an electronic control device including an operation control apparatus as provided in an embodiment of the second aspect of the present application.
According to the electric control device provided by the embodiment of the third aspect of the application, at least the following advantages are provided: the method comprises the steps of obtaining working parameters of a power device in a target time length so as to obtain the average junction temperature of the power device in the target time length, controlling the working state of the power device according to the average junction temperature and the highest allowed junction temperature of the power device, so that the average junction temperature is not higher than the highest allowed junction temperature, integrating factors such as ambient temperature, heat dissipation conditions, voltage and thermal resistance of the power device, monitoring the average junction temperature of the power device in the target time length by taking the target time length as a period, limiting the working current of the power device, and controlling the power device more stably by taking the target time length as the period, so that the power device can be prevented from being damaged due to overcurrent to a certain extent, and the stability of system operation is improved.
In a fourth aspect, embodiments of the present application provide a computer-readable storage medium storing computer-executable instructions, where the computer-executable instructions are configured to cause a computer to perform a method for overcurrent protection of a power device as provided in the embodiments of the first aspect of the present application.
Additional features and advantages of the present application will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the present application. The objectives and other advantages of the application may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
Drawings
The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the example serve to explain the principles of the invention and not to limit the invention.
The invention is further described below with reference to the accompanying drawings and examples;
fig. 1 is a flowchart illustrating steps of a method for overcurrent protection of a power device according to an embodiment of the present application;
FIG. 2 is a schematic diagram of a thermal resistance model of a power device provided herein;
fig. 3 is a flowchart of detailed steps of an overcurrent protection method for a power device according to an embodiment of the present application;
fig. 4 is a flowchart illustrating a detailed step of an overcurrent protection method for a power device according to an embodiment of the present application;
fig. 5 is a flowchart of a detailed step of an overcurrent protection method for a power device according to an embodiment of the present application;
fig. 6 is an overall flowchart of an overcurrent protection method for a power device according to an embodiment of the present application;
fig. 7 is a logic control diagram of an overcurrent protection method for a power device according to an embodiment of the present application;
fig. 8 is a schematic structural diagram of an operation control device according to an embodiment of the present application.
Detailed Description
Reference will now be made in detail to the present embodiments of the present application, preferred embodiments of which are illustrated in the accompanying drawings, which are for the purpose of visually supplementing the description with figures and detailed description, so as to enable a person skilled in the art to visually and visually understand each and every feature and technical solution of the present application, but not to limit the scope of the present application.
In the description of the present application, if there are first and second descriptions for distinguishing technical features, the description should not be interpreted as indicating or implying any relative importance or implying any number of indicated technical features or implying any precedence over indicated by the indicated technical features.
In the description of the present application, unless otherwise specifically limited, terms such as set, installed, connected and the like should be understood broadly, and those skilled in the art can reasonably determine the specific meanings of the above terms in the present application in combination with the specific contents of the technical solutions.
At present, a current protection threshold value can be preset according to parameters of a power device, and segmented delay overcurrent protection is performed on the power device according to the current protection threshold value, namely, the operation duration of the power device is set according to a multiple of a working current and the current protection threshold value, the mode performs overcurrent protection only according to the current size and the duration, and influences of other factors, such as the ambient temperature, are ignored, so that the control precision is low, the actually allowed current of the device is larger than the current protection threshold value under the low-temperature condition, the current margin of the device is large, and the problem of excessive protection exists; under the condition of high temperature, the actual allowable current of the device is smaller than the current protection threshold, the device can run in an overcurrent mode, and the problem of protection failure exists.
Based on this, the embodiments of the present application provide an overcurrent protection method for a power device, an operation control device, an electronic control device, and a computer-readable storage medium, which can perform relatively accurate current limiting control on the power device, and avoid the power device from being damaged due to overheating to a certain extent.
The embodiments of the present application will be further explained with reference to the drawings.
Referring to fig. 1, fig. 1 is a flowchart illustrating steps of an overcurrent protection method for a power device according to an embodiment of the present application, and a first aspect of the present application provides an overcurrent protection method for a power device, where the overcurrent protection method for a power device may include step S100, step S200, and step S300.
S100, acquiring working parameters of a power device in a target duration;
step S200, determining the average junction temperature of the power device in a target time length according to the working parameters;
and step S300, controlling the working state of the power device according to the average junction temperature and the highest allowable junction temperature so as to enable the average junction temperature not to be higher than the highest allowable junction temperature.
In an exemplary embodiment, working parameters of a power device within a target time length are obtained, an average junction temperature of the power device within the target time length is determined according to the working parameters, whether the operating state of the power device is good or not can be judged according to the average junction temperature and the highest allowed junction temperature of the power device, the operating state of the power device within the next target time length is controlled, when the average junction temperature is detected to be larger than the highest allowed junction temperature, the current overload of the power device is indicated at the moment, the operating current of the power device is reduced, so that the average junction temperature is not higher than the highest allowed junction temperature, the target time length is taken as a period, the average junction temperature of the power device within the target time length is monitored, the operating current of the power device is limited, the target time length is taken as the period to perform more stable control on the power device, the power device can be prevented from being damaged due to overcurrent to a certain extent, the stability of system operation is improved, the working state of the power device is controlled according to the junction temperature, and factors such as ambient temperature, heat dissipation conditions, voltage and thermal resistance of the power device can be integrated, so that the control is more accurate, the power device can be prevented from being protected from being over-protected, not over-current, or failing in time, and the protection situation can also be prevented from occurring.
As will be understood by those skilled in the art, the junction temperature of the power device is calculated by the formula: t is a unit of j ＝T c +P×R th (ii) a Wherein T is j To junction temperature, T c Is the case temperature, P is the power consumption of the power device, R th Is the thermal resistance of the power device. The power consumption of the power device may be obtained according to an operating parameter of the power device, and it is understood that the operating parameter of the power device may include a case temperature. In this embodiment, R th For the steady-state thermal resistance of the power device, the average junction temperature of the power device within the target time length can be obtained according to the average shell temperature, the average power consumption and the steady-state thermal resistance between the crusts.
In some embodiments, a temperature sensor may be disposed on a surface of a package casing of the power device, and the case temperature of the power device is obtained through the temperature sensor, but the embodiment does not specifically limit a manner of obtaining the case temperature, and the case temperature may also be obtained through other operating parameters and operating environment parameters of the power device, which is also within the protection scope of the embodiment.
In an exemplary embodiment, the target duration is a time when the thermal resistance of the power device tends to be stable in a thermal resistance model, and the thermal resistance model of the power device, i.e., a thermal resistance-thermal capacitance thermal circuit model, is an inherent physical property of the power device and can be generally obtained by referring to a product specification. FIG. 2 is a schematic diagram of a thermal resistance model of a power device provided in the present application, as shown in FIG. 2, whereinT j To junction temperature, T c For the case temperature, it can be understood by those skilled in the art that the thermal resistance-thermal capacity thermal circuit model can be obtained by performing experimental tests on the power device, and the values of the equivalent thermal resistance and the equivalent thermal capacity in the model can be obtained by fitting the experimental measurements. According to the thermal resistance model, the transient thermal impedance can be approximated as:
wherein Z th (t) transient thermal impedance as a function of time, n is the order of the thermal group model, τ i ＝R i ×C i ，R i Is the equivalent thermal resistance of the ith order, C i The equivalent heat capacity of the ith order, according to the formula, the transient thermal impedance tends to be stable along with the pulse duration.
In this embodiment, the target duration is a time when the thermal resistance of the power device tends to be stable, the time when the thermal resistance tends to be stable may be a time when a change rate of the thermal resistance is less than one thousandth in the following 1ms, or may be a time when the thermal resistance value reaches 99% of a steady-state thermal resistance value, and the present embodiment does not specifically limit the target duration as long as the time when the thermal resistance of the power device tends to be stable can be represented. It can be understood that, in the embodiment, the average junction temperature of the power device is calculated by using the steady-state thermal resistance, and the junction-crust thermal resistance of the power device can tend to be stable in a target time period, so that the calculation result is more accurate, and the error is smaller.
It can be understood that the time that the thermal resistance of the power device tends to be stable is generally short, so that in the overcurrent protection method of the power device provided by the embodiment of the application, the response time is short, and the working state of the power device can be timely adjusted when the power device is in overcurrent, so that damage of the power device due to overcurrent is avoided to a certain extent, and the stability of an equipment system is improved.
It should be noted that the target time length may be equal to or longer than the time when the thermal resistance of the power device tends to be stable, and the calculation error of the average junction temperature may be reduced, which is within the protection range of the embodiment.
As shown in fig. 3, fig. 3 is a flowchart illustrating a detailed step of an overcurrent protection method for a power device according to an embodiment of the present application, where the step S300 in fig. 1 may include a step S310, a step S320, and a step S330.
Step S310, determining a power device conduction current limit value of a power device according to the average junction temperature and the highest allowed junction temperature;
step S320, obtaining the conducting duty ratio needed by the power device in the next period according to the conducting current limit value of the power device, the current needed by the system in the next period and the conducting current of the current actual power device;
and step S330, adjusting the conduction duty ratio of the power device according to the conduction duty ratio required by the power device in the next period.
In an exemplary embodiment, the power device is installed in an electronic control device, and the electronic control device can determine a theoretical current value of its own power device in a next period according to an operating condition and an operating requirement. According to the average junction temperature and the highest allowed junction temperature of the power device in the target time length, a conduction current limit value of the power device can be determined, the conduction duty ratio required by the power device in the next period is obtained according to the conduction current limit value of the power device, the current required by a system in the next period and the conduction current of the current actual power device, and the conduction duty ratio of the power device in the next period is adjusted according to the conduction duty ratio required by the power device in the next period, so that the amplitude limiting control of the working current of the power device is realized, and the average junction temperature of the power device is not higher than the highest operation junction temperature. In this embodiment, the required on-duty ratio of the power device in the next period is obtained according to the on-current limit value of the power device, the current required by the system in the next period, and the on-current of the actual power device at present, so that relatively accurate current limiting control can be achieved, and the power device is subjected to overcurrent protection, so that the on-current of the power device in the next period is not higher than the on-current limit value of the power device, thereby ensuring that the junction temperature of the power device is not higher than the highest allowed junction temperature, reducing the current margin of the power device, and meeting the working requirements of the electronic control device as much as possible.
It can be understood that the on-current of the power device is an operating current of the power device, the on-current of the actual power device may refer to an average current of the power device within the current target time duration, and the on-current limit value of the power device may refer to a maximum allowable current of the power device.
In this embodiment, the adjustment period of the operating current of the power device may be one target duration or a plurality of target durations, which are all within the protection scope of this embodiment.
As can be understood by those skilled in the art, the limiting value of the on-current of the power device can be obtained through PI adjustment according to the average junction temperature, the maximum allowed junction temperature and the operating parameters of the power device.
As shown in fig. 4, fig. 4 is a flowchart illustrating a detailed step of an overcurrent protection method for a power device according to an embodiment of the present application, where the step S320 in fig. 3 may include a step S321 and a step S322.
Step S321, in response to the fact that the limiting value of the conduction current of the power device is larger than or equal to the current required by the system in the next period, taking the current required by the system in the next period as the current required by the power device in the next period, and obtaining the conduction duty ratio required by the power device in the next period according to the current required by the power device in the next period and the conduction current of the current actual power device;
step S322, in response to that the power device on-current limit value is smaller than the current required by the system in the next period, taking the power device on-current limit value as the current required by the power device in the next period, and obtaining the on-duty ratio required by the power device in the next period according to the current required by the power device in the next period and the on-current of the current actual power device.
In an exemplary embodiment, under the condition that the limiting value of the on-state current of the power device is greater than or equal to the on-state current of the power device in the next period, it is stated that the on-state current of the power device in the next period is safe to operate, so that the on-state current of the power device in the next period can be used as the on-state current of the power device in the next period, and the on-state duty ratio of the power device in the next period is obtained according to the on-state current of the power device in the next period and the current actual on-state current of the power device, so that the on-state current of the power device in the next period is the on-state current of the power device in the next period, the operating requirement of the electronic control device is met, and the junction temperature of the power device is not higher than the highest allowable junction temperature; under the condition that the limiting value of the conduction current of the power device is smaller than the current required by the system in the next period, the situation shows that if the current required by the system in the next period of the power device is possible to generate an overcurrent phenomenon and the risk of damage exists, therefore, the limiting value of the conduction current of the power device can be used as the current required by the power device in the next period, and the conduction duty ratio required by the power device in the next period is obtained according to the current required by the power device in the next period and the current conduction current of the actual power device, so that the junction temperature of the power device is not higher than the highest allowable junction temperature, and a stable and accurate overcurrent protection function is realized.
As shown in fig. 5, fig. 5 is a flowchart illustrating a detailed step of an overcurrent protection method for a power device according to an embodiment of the present application, where the step S200 in fig. 1 may include a step S210, a step S220, and a step S230.
Step S210, obtaining the average power consumption and the average shell temperature of the power device in a target time length according to the working parameters;
step S220, determining average crusting temperature rise according to average power consumption and steady-state thermal resistance of the power device;
and step S230, determining the average junction temperature according to the average shell temperature and the average crusting temperature rise.
In an exemplary embodiment, the power device may be operated within a target duration based on the power device operating within the target durationTaking parameters to obtain the average power consumption and the average shell temperature in the target time length, and determining the average incrustation temperature rise according to the average power consumption and the steady-state thermal resistance of the power device according to a calculation formula of the junction temperature, wherein the average incrustation temperature rise is the difference value between the average incrustation temperature and the average shell temperature of the power device in the target time length, namely delta T jc ＝P×R th ＝T j -T c Wherein Δ T jc Representing the average crusting temperature rise of the power device in a target time length, P representing the average power consumption of the power device in the target time length, R th Representing the steady-state thermal resistance, in the embodiments of the present application, the average incrustation temperature rise of the power device over the target time period is equal to the product of the average power consumption and the steady-state thermal resistance. And adding the average shell temperature and the average crusting temperature rise to obtain the average junction temperature of the power device in the target time length.
In some embodiments of the present application, the operating parameters of the power device may include operating voltage, operating current, and case temperature, the average power consumption of the power device may be obtained according to the operating current and the operating voltage, the average case temperature of the power device may be obtained according to the case temperature within the target duration, the case temperature of the power device may be obtained by direct measurement or indirect measurement, and the case temperature may be directly measured by using a temperature sensor or indirectly calculated according to the ambient temperature and other parameters.
It can be understood that, in the embodiment of the present application, a voltage acquisition circuit for acquiring the operating voltage of the power device may be provided, and a current acquisition circuit for acquiring the operating current of the power device may also be provided, so as to acquire the operating parameter of the power device.
In one embodiment, the average power consumption of the power device is equal to the product of the average voltage and the average current of the power device in the target time period, i.e., P = U × I, where P represents the average power consumption, U represents the average voltage, and I represents the average current; wherein the average voltage can be obtained according to the working voltage, and the average current can be obtained according to the working current.
It is understood that the average power consumption may also be obtained according to the average voltage and the resistance, and may also be obtained according to the average current and the resistance, and the embodiment does not specifically limit the manner of obtaining the average power consumption, as long as the average power consumption can be obtained according to the operating parameters, and is within the protection scope of the embodiment.
Referring to fig. 6 and 7, fig. 6 is a complete flowchart of an overcurrent protection method for a power device provided in an embodiment of the present application, fig. 7 is a logic control diagram of the overcurrent protection method for the power device provided in the embodiment of the present application, in fig. 7, U represents an average voltage of the power device in a target duration, I represents an average current of the power device in the target duration, that is, an on-current of the actual power device in a current target duration, and R represents an average current of the power device in the target duration th Denotes the steady state thermal resistance, T, of the power device c Represents the average case temperature of the power device over the target time period. The embodiment of the application provides an overcurrent protection method of a power device, wherein the power device is arranged in an electric control device, the electric control device also comprises a controller, and a voltage acquisition circuit is arranged on the controller and used for acquiring the working voltage of the power device; and the current acquisition circuit is arranged and used for acquiring the working current of the power device. Based on a thermal resistance-thermal capacitance thermal circuit model of the power device, the time for the thermal resistance of the power device to tend to be stable under the action of a single pulse is obtained, wherein the time for the thermal resistance to tend to be stable can be the time for which the thermal resistance value is equal to 99% of the steady-state thermal resistance value, the time for the thermal resistance to tend to be stable is set as a target time length, and the controller obtains the working voltage and the working current of the power device in the target time length. The surface of a shell of the power device is provided with a temperature sensor, a controller can acquire the shell temperature of the power device through the temperature sensor, and the average voltage and the average current of the power device in a target time length are acquired according to the working voltage and the working current of the power device, so that the average power consumption is acquired, and is equal to the average voltage multiplied by the average current; and obtaining the average shell temperature of the power device in the target time length according to the shell temperature obtained by the temperature sensor, and obtaining the average junction temperature of the power device in the target time length according to a calculation formula of the junction temperature. Steady state thermal resistance can be obtained by looking up powerThe specification of the device is obtained. According to the average junction temperature and the highest allowable junction temperature, a power device breakover current limiting value corresponding to the target time length can be obtained on the basis of the average current and the average junction temperature in the target time length and the highest running junction temperature through PI regulation, and the power device breakover current limiting value is an estimated value of the maximum allowable current; under the condition that the limiting value of the conduction current of the power device is larger than or equal to the current required by the system in the next period, the current required by the system in the next period of the power device is safe to operate, so that the current required by the system in the next period can be used as the current required by the power device in the next period, the conduction duty ratio required by the power device in the next period is obtained through PI regulation according to the current required by the power device in the next period and the conduction current of the current actual power device, the conduction duty ratio of the power device is regulated according to the conduction duty ratio required by the power device in the next period, the conduction current in the next period of the power device is the current required by the system in the next period, the working requirement of the electric control equipment is met, and the junction temperature of the power device is not higher than the highest allowable junction temperature; under the condition that the conduction current limit value of the power device is smaller than the current required by the system in the next period, the situation that if the current required by the system in the next period of the power device runs, an overcurrent phenomenon may occur, and the risk of damage exists, therefore, the conduction current limit value of the power device can be used as the current required by the power device in the next period, the conduction duty ratio required by the power device in the next period can be obtained through PI regulation according to the current required by the power device in the next period and the current of the actual power device, the conduction duty ratio of the power device can be regulated according to the conduction duty ratio required by the power device in the next period, so that the conduction current in the next period of the power device is used as the conduction current limit value of the power device, the junction temperature of the power device is prevented from being higher than the highest allowable junction temperature, stable and accurate current limiting control can be provided, and the overcurrent protection function is realized. For example, if the current required by the system in the next period is 12A, and the conduction current limit value of the power device is determined to be 8A according to the operating parameters and the shell temperature of the power device in the target time length, the conduction duty ratio of the power device is adjusted to control the conduction current of the power device in the next period to be 8A,so that the junction temperature of the power device is not higher than the highest allowable junction temperature, the damage of the device is avoided, and the current allowance is avoided as much as possible; it is understood that the power device on-current limit value is updated in a cycle of the target time length. If the current required by the system in the next period is 12A, but the current limit value of the power device on-state current determined at the time is 15A, the working current of the power device in the next period can be controlled to be 12A, the working requirement of the electric control equipment can be met, and the junction temperature of the power device is not higher than the highest allowed junction temperature. According to the method provided by the embodiment, the target duration is taken as a period, the average junction temperature of the power device in the target duration is monitored, the working current of the power device is limited, the power device can be controlled more stably by taking the target duration as a period, the power device can be prevented from being damaged due to overcurrent to a certain extent, the power device is effectively protected, and the running stability of equipment is improved.
Referring to fig. 8, fig. 8 is a schematic structural diagram of an operation control apparatus 800 according to an embodiment of the present application, and the embodiment of the present application further provides an operation control apparatus 800, where the operation control apparatus 800 includes at least one control processor 810 and a memory 820 for communication connection with the at least one control processor 810; the memory 820 stores instructions executable by the at least one control processor 810, the instructions being executable by the at least one control processor 810 to enable the at least one control processor 810 to perform a method of overcurrent protection for a power device as provided by an embodiment of the method of the present application. According to the overcurrent protection method of the power device, the working parameters and the shell temperature of the power device in the target time length are obtained, so that the average junction temperature of the power device in the target time length is obtained, the working state of the power device is controlled according to the average junction temperature and the highest allowed junction temperature of the power device, the average junction temperature is not higher than the highest allowed junction temperature, the factors such as the ambient temperature, the heat dissipation condition, the voltage and the thermal resistance of the power device are integrated, the target time length is taken as a period, the average junction temperature of the power device in the target time length is monitored, the working current of the power device is limited, the power device is controlled more stably by taking the target time length as the period, the power device can be prevented from being damaged due to overcurrent to a certain degree, and the running stability of a system is improved.
The embodiment of the present application further provides an electronic control device, including the operation control apparatus 900 provided in the embodiment of the present application, where the electronic control device is capable of executing the overcurrent protection method of the power device provided in the embodiment of the present application, obtaining the operating parameters and the case temperature of the power device within the target time duration, thereby obtaining the average junction temperature of the power device within the target time duration, controlling the operating state of the power device according to the average junction temperature and the highest allowed junction temperature of the power device, so that the average junction temperature is not higher than the highest allowed junction temperature, integrating the ambient temperature, the heat dissipation condition, the voltage and the thermal resistance of the power device, and taking the target time duration as a cycle, monitoring the average junction temperature of the power device within the target time duration, limiting the operating current of the power device, performing more stable control on the power device taking the target time duration as a cycle, being capable of avoiding damage of the power device due to overcurrent to a certain extent, and improving the stability of system operation.
The embodiment of the present application further provides a computer-readable storage medium, where computer-executable instructions are stored, and the computer-executable instructions are used to enable a computer to execute the method for overcurrent protection of a power device according to the embodiment of the present application. According to the method, the working parameters and the shell temperature of the power device in the target time length are obtained, so that the average junction temperature of the power device in the target time length is obtained, the working state of the power device is controlled according to the average junction temperature and the highest allowed junction temperature of the power device, the average junction temperature is not higher than the highest allowed junction temperature, the factors such as the ambient temperature, the heat dissipation condition, the voltage and the thermal resistance of the power device are integrated, the average junction temperature of the power device in the target time length is monitored by taking the target time length as a period, the working current of the power device is limited, the power device is controlled more stably by taking the target time length as the period, the damage of the power device due to overcurrent can be avoided to a certain extent, and the running stability of a system is improved.
One of ordinary skill in the art will appreciate that all or some of the steps, systems, and methods disclosed above may be implemented as software, firmware, hardware, and suitable combinations thereof. Some or all of the physical components may be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application specific integrated circuit. Such software may be distributed on computer readable media, which may include computer storage media or non-transitory media and communication media or transitory media. The term computer storage media includes volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data as is well known to those of ordinary skill in the art. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks, DVD, or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can accessed by a computer. In addition, communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media as known to those skilled in the art.
The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the gist of the present invention.
Claims (10)
1. An overcurrent protection method for a power device, the method comprising:
acquiring working parameters of the power device in a target time length;
determining the average junction temperature of the power device within the target time length according to the working parameters;
and controlling the working state of the power device according to the average junction temperature and the highest allowable junction temperature so as to enable the average junction temperature not to be higher than the highest allowable junction temperature.
2. The method according to claim 1, wherein the target duration is a time when thermal resistance of the power device tends to be stable in a thermal resistance model.
3. The method for overcurrent protection of a power device according to claim 1, wherein the controlling the operating state of the power device according to the average junction temperature and the highest allowed junction temperature comprises:
determining a power device conduction current limit value of the power device according to the average junction temperature and the highest allowable junction temperature;
obtaining the conducting duty ratio required by the power device in the next period according to the conducting current limit value of the power device, the current required by the system in the next period and the conducting current of the current actual power device;
and adjusting the conduction duty ratio of the power device according to the required conduction duty ratio of the power device in the next period.
4. The method for protecting the power device from the overcurrent, according to claim 3, wherein the obtaining the on-duty ratio required by the power device in the next cycle according to the on-current limit value of the power device, the current required by the system in the next cycle, and the on-current of the actual power device at present comprises:
responding to the fact that the power device conducting current limiting value is larger than or equal to the current required by the next period system, taking the current required by the next period system as the current required by the next period power device, and obtaining the conducting duty ratio required by the next period power device according to the current required by the next period power device and the conducting current of the current actual power device;
and in response to the fact that the power device conduction current limit value is smaller than the current required by the next period of the system, taking the power device conduction current limit value as the current required by the next period of the power device, and obtaining the conduction duty ratio required by the next period of the power device according to the current required by the next period of the power device and the current conduction current of the current actual power device.
5. The method of claim 1, wherein the determining an average junction temperature of the power device over the target time period according to the operating parameter comprises:
obtaining the average power consumption and the average shell temperature of the power device in the target time length according to the working parameters;
determining an average crusting temperature rise according to the average power consumption and the steady-state thermal resistance of the power device;
and determining the average junction temperature according to the average shell temperature and the average crusting temperature rise.
6. The method according to claim 5, wherein the operating parameters comprise an operating voltage, an operating current and a case temperature, and the average power consumption is obtained according to the operating voltage and the operating current; the average shell temperature is obtained from the shell temperature.
7. The method of claim 5, wherein the average incrustation temperature rise is equal to a product of the average power consumption and the steady-state thermal resistance.
8. An operation control device comprising at least one control processor and a memory for communicative connection with the at least one control processor; the memory stores instructions executable by the at least one control processor to enable the at least one control processor to perform a method of over-current protection of a power device as claimed in any one of claims 1 to 7.
9. An electric control apparatus characterized by comprising the operation control device according to claim 8.
10. A computer-readable storage medium storing computer-executable instructions for causing a computer to perform the method for overcurrent protection of a power device according to any one of claims 1 to 7.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211377362.3A CN115693626A (en) | 2022-11-04 | 2022-11-04 | Overcurrent protection method, operation control device and electric control equipment of power device |
| PCT/CN2023/085572 WO2024093117A1 (en) | 2022-11-04 | 2023-03-31 | Overcurrent protection method for power device, operation control apparatus, and electronic control device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
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| CN202211377362.3A CN115693626A (en) | 2022-11-04 | 2022-11-04 | Overcurrent protection method, operation control device and electric control equipment of power device |
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| CN115693626A true CN115693626A (en) | 2023-02-03 |
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| CN202211377362.3A Pending CN115693626A (en) | 2022-11-04 | 2022-11-04 | Overcurrent protection method, operation control device and electric control equipment of power device |
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| WO (1) | WO2024093117A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2024093117A1 (en) * | 2022-11-04 | 2024-05-10 | 广东美的制冷设备有限公司 | Overcurrent protection method for power device, operation control apparatus, and electronic control device |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| US8299767B1 (en) * | 2006-08-18 | 2012-10-30 | Picor Corporation | Dynamic safe operating area control |
| CN103986319B (en) * | 2014-05-19 | 2017-02-15 | 徐州中矿大传动与自动化有限公司 | Elevator frequency converter IGBT over-temperature closed loop protection method based on switching frequency adjustment |
| CN113765058B (en) * | 2020-06-03 | 2023-05-12 | 株洲中车时代电气股份有限公司 | Chopper circuit protection method and system |
| CN114447943A (en) * | 2022-03-25 | 2022-05-06 | 国家电网有限公司华北分部 | Method and device for determining current limiting value of static var generator |
| CN115236473A (en) * | 2022-06-30 | 2022-10-25 | 广东美芝制冷设备有限公司 | Power device and junction temperature detection method, device, medium and frequency converter system thereof |
| CN115693626A (en) * | 2022-11-04 | 2023-02-03 | 广东美的制冷设备有限公司 | Overcurrent protection method, operation control device and electric control equipment of power device |
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- 2022-11-04 CN CN202211377362.3A patent/CN115693626A/en active Pending
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2024093117A1 (en) * | 2022-11-04 | 2024-05-10 | 广东美的制冷设备有限公司 | Overcurrent protection method for power device, operation control apparatus, and electronic control device |
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