CN118259192A - Current abnormality monitoring device and current abnormality monitoring method - Google Patents

Abstract

The invention provides a current abnormality monitoring device and a current abnormality monitoring method. The current abnormality monitoring device includes a first detection circuit, a second detection circuit, and a control circuit. The first detection circuit detects a first electrical parameter of the power component based on the ith stage of short circuit time. The second detection circuit detects a second electrical parameter of the power component based on the ith stage short-circuit time to generate an ith stage detection signal. The control circuit generates an ith grade heat predictive value according to the first electrical parameter to judge whether the power component is damaged or not, and judges whether the power component is abnormal or not according to the ith grade detection signal to record the ith grade heat predictive value and the ith grade short-circuit time or adjust the ith grade short-circuit time to be the (i+1) th grade short-circuit time.

Description

Current abnormality monitoring device and current abnormality monitoring method

Technical Field

The present invention relates to electronic devices, and more particularly, to a current abnormality monitoring device and a current abnormality monitoring method.

Background

Electronic products that can use various materials to manufacture power components according to different needs. For miniaturization, the size of the power device is smaller and smaller, and the reaction time of the power device is shortened enough to withstand instantaneous overcurrent (over current). In the preset reaction time, when the energy of the over-current is too large, the power component is slightly damaged to damage the middle oxide layer. At this time, although the power device can operate, the power device may generate leakage current (leakage current) to affect the output power. On the other hand, when the energy of the overcurrent is greater, the power component will be severely damaged and inoperable.

Generally, the over-current detection protection circuit can detect an over-current to protect the power device from being severely damaged. However, the over-current detection protection circuit cannot know the damage condition of the power device, so that the problem of electrical abnormality cannot be eliminated.

Disclosure of Invention

The embodiment of the invention provides a current abnormality monitoring device which can monitor the electrical abnormality of overcurrent and can monitor the health of a power component to eliminate the electrical abnormality problem caused by leakage current.

The current abnormality monitoring device provided by the embodiment of the invention is suitable for a power component. The current abnormality monitoring device includes a first detection circuit, a second detection circuit, and a control circuit. The first detection circuit is coupled to the power component. The first detection circuit is used for detecting a first electrical parameter of the power component based on the ith stage short-circuit time. The second detection circuit is coupled to the power component. The second detection circuit is used for detecting a second electrical parameter of the power component based on the ith stage short-circuit time to generate an ith stage detection signal. The control circuit is coupled to the first detection circuit and the second detection circuit. The control circuit is used for generating an ith grade heat predicted value according to the first electrical parameter to judge whether the power component is damaged or not, and judging whether the power component is abnormal or not according to the ith grade detection signal. When the power component is judged to be damaged and is abnormal in operation, the control circuit records an ith grade heat predictive value and an ith grade short-circuit time. When the power component is judged to be non-damaged and is not abnormal in operation, the control circuit adjusts the ith stage short-circuit time to be the (i+1) th stage short-circuit time. i is a non-negative integer.

The embodiment of the invention also provides a current anomaly monitoring method. The current anomaly monitoring method is applicable to a power component and comprises the following steps. And detecting a first electrical parameter of the power component based on the ith stage short-circuit time through a first detection circuit. And detecting a second electrical parameter of the power component based on the ith stage short-circuit time by a second detection circuit to generate an ith stage detection signal. The control circuit is used for generating an ith grade heat predictive value according to the first electrical parameter to judge whether the power component is damaged or not, and judging whether the power component is abnormal or not according to the ith grade detection signal. When the power component is judged to be damaged and is abnormal in operation, the ith grade heat predicted value and the ith grade short-circuit time are recorded through the control circuit. When the power component is judged to be non-damaged and is abnormal in operation, the ith short-circuit time is adjusted to be the (i+1) th short-circuit time through the control circuit. i is a non-negative integer.

Based on the above, the current anomaly monitoring device and the current anomaly monitoring method according to the embodiments of the present invention can detect different electrical parameters of the power device, and determine whether the power device is damaged due to an electrical anomaly of an overcurrent or not and whether the power device is abnormal in operation due to an electrical anomaly of a leakage current or not according to the electrical parameters. Therefore, the current abnormality monitoring device can monitor abnormal overcurrent and monitor the health degree of the power component in real time so as to eliminate various electrical abnormality problems.

In order to make the above features and advantages of the present invention more comprehensible, embodiments accompanied with figures are described in detail below.

Drawings

FIG. 1 is a block diagram of a current anomaly monitoring device according to an embodiment of the present invention;

FIG. 2 is a flow chart of a current anomaly monitoring method according to an embodiment of the present invention;

FIG. 3 is a block diagram of a current anomaly monitoring device according to an embodiment of the present invention;

FIG. 4 is a schematic diagram illustrating an embodiment of a current anomaly monitoring method according to the present invention;

FIG. 5 is a circuit diagram of a second detection circuit according to the embodiment of FIG. 3;

FIG. 6 is a schematic diagram illustrating the operation of the second detection circuit according to the embodiment of FIG. 5;

Fig. 7 is a schematic diagram illustrating the operation of the second detection circuit according to the embodiment of fig. 5.

Reference numerals illustrate:

100. 300: a current abnormality monitoring device;

110. 310: a first detection circuit;

120. 320: a second detection circuit;

130. 330: a control circuit;

200: a power assembly;

311: an oscilloscope;

321: a differential circuit;

322: an integrating circuit;

323: a comparison circuit;

340: a driving circuit;

350: a short-circuit protection circuit;

360: a signal generator;

400: an inductive load clamping circuit;

s1: an electrical parameter;

S2: detecting a signal;

D1: a diode;

ESC, tot: a heat predictive value;

ID: outputting a current;

IG: controlling the current;

IG': an amplified control current;

L1: an inductor;

l1 to L4: a wire;

s210 to S250: a step of;

S410 to S460: a module;

TSC: short circuit time;

VDD: a power supply voltage;

vref, vref_1, vref_2: a reference voltage;

VDS: outputting a voltage;

VQG: detecting a voltage;

Vref_2_HL, vref_2_LL: voltage value.

Detailed Description

Reference will now be made in detail to the exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.

FIG. 1 is a block diagram of a current anomaly monitoring device according to an embodiment of the invention. Referring to fig. 1, a current anomaly monitoring device 100 can be applied to a power component 200 to monitor various electrical anomalies of the power component 200. In this embodiment, the power device 200 may be, for example, a semiconductor device made of Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET), an insulated gate bipolar transistor (Insulated Gate Bipolar Transistor, IGBT), silicon carbide (SiC), or gallium nitride (GaN).

In the present embodiment, the current anomaly monitoring device 100 and the power component 200 can be integrated in the same chip. The aforementioned Chip may be, for example, a System On Chip (SOC), which may include a microcontroller, a microprocessor, a digital signal processor, and other processors (such as the control circuit 130), as well as read-only memory (ROM), random Access Memory (RAM), electrically erasable programmable read-only memory (EEPROM), flash memory, and other memories, and may run operating systems and applications. In this embodiment, the chip can be applied to an electrical testing device of a motor, a power converter or a power module.

In the embodiment shown in fig. 1, the current anomaly monitoring device 100 may include a first detection circuit 110, a second detection circuit 120, and a control circuit 130. The first detection circuit 110 and the second detection circuit 120 are respectively coupled to the power device 200. In this embodiment, the first detection circuit 110 may be, for example, an overcurrent detection circuit to monitor the overcurrent of the power component 200. The second detection circuit 120 may be, for example, a leakage current detection circuit to monitor the leakage current of the power device 200.

In the present embodiment, the control circuit 130 is coupled to the first detection circuit 110 and the second detection circuit 120. The control circuit 130 may receive the data or the signals (such as the parameter S1 and the signal S2) detected by the first detection circuit 110 and the second detection circuit 120, respectively, and perform the determining operation on the electrical anomaly according to the data or the signals. In the present embodiment, the control circuit 130 may be, for example, a signal converter, a field programmable gate array (Field Programmable GATE ARRAY, FPGA), a central processing unit (Central Processing Unit, CPU), or other programmable general purpose or special purpose Microprocessor (Microprocessor), digital Signal Processor (DSP), programmable controller, application SPECIFIC INTEGRATED Circuits (ASIC), programmable logic device (Programmable Logic Device, PLD), or other similar device or combination of these devices, which may be loaded with and execute associated firmware or software to implement the computing and control functions.

Fig. 2 is a flowchart of a current anomaly monitoring method according to an embodiment of the invention. Referring to fig. 1 and 2, the current anomaly monitoring device 100 may perform steps S210 to S250 as follows. In the present embodiment, the current anomaly monitoring device 100 can repeatedly execute steps S210 to S240 to monitor and record the electrical operation of the power device 200 in response to different short-circuit times until the power device 200 is damaged and cannot operate to stop at step S250. The following embodiment illustrates the steps of the current anomaly monitoring device 100 monitoring operation at the ith stage, where i is a non-negative integer, and illustrates the ith stage short circuit time.

In step S210, the first detection circuit 110 detects the first electrical parameter S1 of the power component 200 based on the i-th stage short circuit time. The first detection circuit 110 provides the first electrical parameter S1 to the control circuit 130. In the present embodiment, the first electrical parameter S1 is an electrical parameter related to the over-current, and may be, for example, an output current (e.g., the output current ID shown in fig. 3) and an output voltage (e.g., the output voltage VDS shown in fig. 3) of the power device 200.

In step S220, the second detection circuit 120 detects the second electrical parameter of the power device 200 based on the i-th stage short circuit time to generate the i-th stage detection signal S2. The second detection circuit 120 supplies the i-th stage detection signal S2 to the control circuit 130. In the present embodiment, the second electrical parameter is an electrical parameter related to the leakage current, and may be, for example, a control current (e.g., the control current IG shown in fig. 3) including the power device 200.

In step S230, the control circuit 130 generates an i-th stage heat prediction value according to the first electrical parameter S1 to determine whether the power component 200 is damaged. That is, the control circuit 130 converts the current and/or voltage (i.e., the first electrical parameter S1) detected based on the i-th stage short circuit time into a thermal parameter (i.e., the i-th stage thermal pre-estimation value) to determine whether the power component 200 is damaged by the overcurrent.

If the power device 200 is determined to be non-damaged, it means that the power device 200 can withstand the large current in the ith stage of short circuit time without occurrence or occurrence of electrical abnormality of overcurrent. The current anomaly monitoring device 100 performs step S240 to continue monitoring. On the contrary, if the power component 200 is determined to be damaged, it means that the power component 200 cannot bear the corresponding large current in the ith stage of short circuit time, and the electrical abnormality of the overcurrent has occurred or will occur. The current anomaly monitoring device 100 performs step S250 to further monitor the health of the power component 200.

Further, in step S230, the control circuit 130 determines whether the power component 200 is abnormally operated according to the i-th stage detection signal S2. That is, the control circuit 130 analyzes the current and/or voltage detected based on the i-th stage short circuit time (i.e., the i-th stage detection signal S2) and accordingly determines whether the leakage current is too large to make the power component 200 inoperable.

If the power device 200 is determined to be abnormal in non-operation, it means that the power device 200 is still operable even if damaged, and no electrical abnormality of leakage current occurs or does not occur, so the control circuit 130 determines that the power device 200 is abnormal in non-operation. The current anomaly monitoring device 100 executes step S240. On the contrary, if the power device 200 is determined to be abnormal, it means that the power device 200 is damaged and cannot operate, and the electrical abnormality of the leakage current has occurred or will occur, so the control circuit 130 determines that the power device 200 is abnormal. The current anomaly monitoring device 100 executes step S250.

In step S240, when the power component 200 is determined to be non-damaged and is not abnormal in operation, the control circuit 130 adjusts the i-th stage short-circuit time to be the i+1th stage short-circuit time, so that the current abnormality monitoring apparatus 100 re-executes step S210 to continue monitoring based on the i+1th stage short-circuit time. That is, when the power component 200 is damaged but still operable, the current anomaly monitoring device 100 monitors the operation of the power component 200 in response to another short-circuit time.

In step S250, when the power component 200 is judged to be damaged and is abnormally operated, the control circuit 130 records the i-th stage heat predicted value and the i-th stage short time. That is, when the power device 200 is damaged and cannot operate, the current anomaly monitoring device 100 records electrical parameters sufficient to disable the power device 200.

It should be noted that the current anomaly monitoring device 100 can determine whether the power device 200 is damaged due to an electrical anomaly of an overcurrent or not and whether the power device 200 is abnormal due to an operation anomaly due to an electrical anomaly of a leakage current according to a plurality of electrical parameters (i.e., the first electrical parameter S1 and the i-th level detection signal S2) of the power device 200. Therefore, the current anomaly monitoring device 100 can estimate the protection triggering safety time (i.e. the short-circuit time) of the power component 200 in response to the overcurrent, and can monitor the health and the electrical anomaly of the power component 200 in real time.

FIG. 3 is a block diagram of a current anomaly monitoring device according to an embodiment of the invention. Referring to fig. 3, the current anomaly monitoring device 300 may include a first detection circuit 310, a second detection circuit 320, a control circuit 330, a driving circuit 340, and a short protection circuit 350. The circuits 310-330 shown in fig. 3 can be described and analogized with reference to the current anomaly monitoring device 100 shown in fig. 1, and are not repeated here. For convenience of explanation of the present invention, the designation and explanation of the resistor is omitted in fig. 3.

In this embodiment, the power component 200 may be exemplified by a power switch implemented as a MOSFET, for example. The power device 200 and the inductive load clamp circuit 400 may be connected in series between the power supply voltage VDD and ground. The inductive load clamp circuit 400 may control the current (i.e., the output current ID) flowing between the drain terminal and the source terminal of the power device 200 by adjusting the pulse width by the control circuit 330. In the present embodiment, the inductive load clamping circuit 400 may include a diode D1 and an inductor L1 coupled in parallel.

In the present embodiment, the driving circuit 340 is coupled to the power device 200 and the control circuit 330. The driving circuit 340 may output the control current IG and a specific pulse width to the control terminal (i.e., the gate terminal) of the power device 200 according to the instruction of the control circuit 330. For example, the driving circuit 340 may generate a pulse signal with a specific pulse width (e.g., i-th stage short time length) and a specific voltage level as the control current IG. Therefore, the power device 200 can generate the output voltage VDS and the output current ID according to the pulse signal in response to the i-th stage short circuit time.

In the present embodiment, the short-circuit protection circuit 350 is coupled to the power device 200, the first detection circuit 310 and the second detection circuit 320. The short circuit protection circuit 350 may include an over current protection (OverCurrent Protection, OCP) circuit and an over voltage protection (Over Voltage Protection, OVP) circuit. The short-circuit protection circuit 350 may determine whether to turn off the power device 200 according to the i-th level detection signal S2, and may cut off or not cut off the path flowing through the power device 200 during the i-th level short-circuit time to protect the power device 200. In an embodiment, the short-circuit protection circuit 350 may protect the power device 200 according to the first electrical parameter S1 and/or the i-th level detection signal S2.

In some embodiments, the current anomaly monitoring device 300 further includes a signal generator 360 and an oscilloscope 311. The signal generator 360 is coupled to the driving circuit 340. The signal generator 360 may generate the pulse signal (i.e., the control current IG) as described above, and output the pulse signal to the power device 200 through the driving circuit 340. In one embodiment, the signal generator 360 may be integrated with the driving circuit 340.

In some embodiments, an oscilloscope 311 is coupled to both ends of the power component 200. The oscilloscope 311 may detect the output voltage VDS and the output current ID of the power component 200 to operate in conjunction with the first detection circuit 310. In one embodiment, the oscilloscope 311 may be integrated with the first detection circuit 310.

Fig. 4 is a schematic diagram illustrating an operation of a current anomaly monitoring method according to an embodiment of the invention. Referring to fig. 3 and 4, the current anomaly monitoring device 300 may perform the following blocks S410 to S460. In the present embodiment, the current anomaly monitoring device 300 can repeatedly execute the modules S410-S440 to monitor and record the electrical operation of the power device 200 in response to different short-circuit times until the power device 200 is damaged and cannot operate to stop at the module S460.

In block S410, the user may operate the current anomaly monitoring device 300 to set the level 0 output voltage VDS and the level 0 short time TSC. That is, the user can set the initial operation parameters of the current anomaly monitoring device 300. In some embodiments, the 0 th level output voltage VDS and the 0 th level short time TSC may be preset parameters of the current anomaly monitoring device 300 when shipped. The following embodiment illustrates the steps of the current anomaly monitoring device 300 in the i-th stage monitoring operation, and illustrates the i-th stage short circuit time, where i is a non-negative integer.

In block S420, the control circuit 330 receives the output current ID and the output voltage VD (i.e. the first electrical parameter S1) from the first detecting circuit 310. The control circuit 330 determines whether the power component 200 is damaged according to the aforementioned parameter S1, to illustrate another implementation detail about step S230 in fig. 2, and to illustrate in a two-dimensional legend. In the illustration of block S420, the horizontal axis represents the operation time (in units of, for example, microseconds (μs)) of the current anomaly monitoring device 300, and the vertical axis represents the voltage value, the current value, and the heat value (or energy value).

In detail, the control circuit 330 receives the i-th stage heat predictive value ESC, tot generated by integrating the product of the output current ID and the output voltage VDS based on the i-th stage short-circuit time TSC. In the present embodiment, the foregoing integration calculation may be performed by the control circuit 330, for example. In some embodiments, the foregoing integration calculations may be performed, for example, by other calculation circuitry. Other calculation circuits can acquire the waveform signals of the output current ID and the output voltage VDS through the oscilloscope 311 and perform integral calculation according to the waveform signals.

In this embodiment, the integration calculation described above includes the following operations, the control circuit 330 converts the output current ID and the output voltage VDS into digital data through the analog-to-digital converter (Analog to Digital), and performs digital integration based on related firmware or software. The i-th stage heat predictive value ESC, tot may be implemented as shown in the following equation (1). The ESC in equation (1) is the i-th stage heat predictive value ESC, tot, TSC is the i-th stage short time TSC, VDS is the voltage value of the output voltage VDS, ID is the current value of the output current ID, and t is time.

That is, the control circuit 330 accumulates the energy generated by the output current ID and the output voltage VDS during the i-th stage of the short circuit time TSC in response to the power device 200. The control circuit 330 converts the aforementioned energy to heat (i.e., the i-th stage heat estimate ESC, tot) at a default performance (e.g., near 100%).

Continuing with the description above, the control circuit 330 compares the i-th stage heat estimate ESC, tot with the reference heat estimate to determine whether the power assembly 200 is defective. In this embodiment, when the i-th stage heat predictive value ESC, tot is greater than the reference heat predictive value, it indicates that the i-th stage heat predictive value ESC, tot is too large to cause an electrical abnormality of the power module 200 that has occurred or is about to occur an overcurrent. At this time, the control circuit 330 determines that the power component 200 is damaged. The current anomaly monitoring device 300 executes block S430.

In another aspect, when the i-th stage heat predictive value ESC, tot is not greater than the reference heat predictive value, it is indicated that the i-th stage heat predictive value ESC, tot is insufficient to cause an overcurrent electrical anomaly to occur with the power assembly 200. At this time, the control circuit 330 determines that the power component 200 is not damaged. The current anomaly monitoring device 300 re-executes block S420.

In this embodiment, the reference heat predicted value refers to the maximum energy that the power assembly 200 can withstand. When the energy applied to the power assembly 200 is above the reference heat budget, at least a portion of the power assembly 200 (e.g., the crystal surface or oxide thereof) may be damaged. In this embodiment, the reference heat budget value is associated with the size of the power assembly 200. The reference heat forecast may be, for example, a unit of energy provided in advance by the manufacturer of the power assembly 200, or a parameter obtained from an experiment conducted by a third party manufacturer.

In block S430, the control circuit 330 determines that the power component 200 is damaged. Meanwhile, the second detection circuit 320 generates the i-th detection signal S2 according to the control current IG, so that the control circuit 330 further determines whether the power component 200 is abnormal according to the i-th detection signal S2, to illustrate another implementation details about the step S220 and the step S230 in fig. 2.

Referring to fig. 5 in detail, fig. 5 is a circuit diagram of the second detection circuit according to the embodiment of fig. 3. In the present embodiment, the second detection circuit 320 may include a differential circuit 321, an integrating circuit 322, and a comparing circuit 323. The differential input terminal of the differential circuit 321 is coupled to the control terminal of the power component 200 to extract the control current IG. The inverting input of the integrating circuit 322 is coupled to the output of the differentiating circuit 321. The non-inverting input of the integrating circuit 322 is coupled to ground. The inverting input of the comparator 323 is coupled to the output of the integrator 322. The non-inverting input of the comparator circuit 323 receives a variable reference voltage Vref. The output terminal of the comparison circuit 323 is coupled to the control circuit 330 and the short-circuit protection circuit 350 in fig. 3. For convenience of explanation, the reference numerals and descriptions about the resistor and the capacitor are omitted in fig. 5.

In this embodiment, the differential circuit 321 may function as an operational amplifier. The differential circuit 321 may output an amplified control current IG' according to the control current IG. In this embodiment, the integrating circuit 322 may function as an integrator. The integrating circuit 322 may perform an integrating operation according to the amplified control current IG' to generate the i-th stage detection voltage VQG. The foregoing integration operation includes accumulating the charge of the amplified control current IG' using the integrating circuit 322. The comparison circuit 323 may function as a comparator. The comparison circuit 323 can compare the i-th stage detection voltage VQG with the reference voltage Vref to generate an i-th stage detection signal S2. In the present embodiment, the i-th stage detection voltage VQG may correspond to the leakage current of the power component 200. The reference voltage Vref may correspond to a reference leakage current of the power component 200.

In the present embodiment, when the voltage value of the i-th stage detection voltage VQG is not greater than the voltage value of the reference voltage Vref, the leakage current of the power component 200 is not greater than the reference leakage current. That is, the power assembly 200 can operate even if the power assembly 200 is damaged due to an overcurrent. At this time, the comparison circuit 323 generates the i-th stage detection signal S2 having the first value. The first value may be, for example, a low voltage reference level or a logic low level. The i-th level detection signal S2 indicates that the power device 200 is damaged and is operable, so that the control circuit 330 determines that the operation is abnormal. The current anomaly monitoring device 300 executes block S440.

On the other hand, when the voltage value of the i-th stage detection voltage VQG is greater than the voltage value of the reference voltage Vref, it indicates that the leakage current of the power component 200 is greater than the reference leakage current. That is, the power device 200 is damaged due to the overcurrent, and the power device 200 has low health and generates excessive leakage current. At this time, the comparison circuit 323 generates the i-th stage detection signal S2 having the second value. The second value may be, for example, a high voltage reference level or a logic high level. The i-th level detection signal S2 indicates that the power device 200 is damaged and cannot operate, so that the control circuit 330 determines that the power device 200 is abnormal. The current anomaly monitoring device 300 executes block S450.

In block S440, when the power component 200 is determined to be damaged and is not operating abnormally, the control circuit 330 lengthens the short-circuit time in the next stage monitoring operation to adjust the i+1st stage short-circuit time to the i-th stage short-circuit time plus the reference short-circuit time. The current anomaly monitoring device 300 re-executes the block S420 based on the i+1st stage short circuit time to continue monitoring. In this embodiment, the reference short circuit time is associated with the size of the power component 200. The reference short time may be, for example, a unit time provided in advance by a manufacturer of the power component 200, and may be, for example, 100 nanoseconds (ns).

At block S450, when the power component 200 is judged to be damaged and is operating abnormally, the control circuit 330 draws a table or a two-dimensional legend according to the data in the 0 th level monitoring operation to the i th level monitoring operation. In the diagram of the block S450, the horizontal axis represents the voltage value of the output voltage VDS, and the vertical axis represents the short-circuit time TSC (in μs, for example) of the current anomaly monitoring device 300.

In detail, the control circuit 330 records the estimated heat value ESC, tot and the output current ID of the power module 200 during each stage of monitoring operation, and uses the output voltage VDS and the short-circuit time TSC as variables to obtain a diagram indicated by a block S450. Therefore, the control circuit 330 can obtain the electrical operation characteristics of the power device 200 in response to various short-circuit time TSCs, such as over-current endurance and corresponding voltage values, current values, and the like.

In block S460, the control circuit 330 may access the data such as the table or the two-dimensional legend recorded in block S450. The aforementioned data are, for example, the estimated heat value ESC, tot and the short circuit time TSC of the power module 200 during each stage of monitoring operation. In some embodiments, the table or the two-dimensional legend recorded in the module S450 may be used as an electrical operation reference of the power device 200 and other devices with the same specification, so as to be applied in the protection circuit of the power device 200.

FIG. 6 is a schematic diagram illustrating the operation of the second detection circuit according to the embodiment of FIG. 5. In fig. 6, the horizontal axis represents the charge (unit is, for example, coulomb (C)) on the inverting input terminal of the comparison circuit 323 (i.e., the i-th stage detection voltage VQG), and the vertical axis represents the voltage value. FIG. 7 is a schematic diagram illustrating the operation of the second detection circuit according to the embodiment of the present invention. In fig. 7, the horizontal axis represents the operation time (in units of, for example, μs) of the second detection circuit 320, and the vertical axis represents the voltage value.

Referring to fig. 5 to 7, in some conventional detection circuits, a comparison circuit performs a comparison operation according to a reference voltage vref_1. The reference voltage Vref_1 has a fixed voltage value. Therefore, when the non-inverting input terminals of the comparison circuit have different amounts of charge, or when the comparison circuit operates at an arbitrary point in time, the comparison circuit uses the same reference value as a comparison reference. However, when the power component 200 is subjected to different loads, the charges or voltages (corresponding to the detection voltage VQG of fig. 5) at the non-inverting input terminal of the comparison circuit have different corresponding values, so that the comparison circuit outputs a misjudged comparison result.

In this embodiment, the smaller the voltage value of the i-th stage detection voltage VQG, the smaller the amount of charge on this node, and the smaller the current value of the corresponding leakage current. The smaller the current value of the leakage current, the smaller the load (i.e., light load) the power component 200 is subjected to, or the smaller the voltage value of the power supply voltage VDD (e.g., 400V). On the other hand, the larger the voltage value of the i-th stage detection voltage VQG, the larger the amount of charge on this node, and the larger the current value of the corresponding leakage current. The larger the current value of the leakage current, the larger the load (i.e., heavy load) the power component 200 is subjected to, or the larger the voltage value of the power supply voltage VDD (e.g., 800V).

It should be noted that the second detection circuit 320 or the control circuit 330 may adjust the voltage value of the reference voltage Vref received by the non-inverting input terminal of the comparison circuit 323 according to the load of the power component 200, and is exemplarily shown in the reference voltage vref_2 of fig. 6. In fig. 6, when the charge amount is smaller, the reference voltage vref_2 has a first voltage value Vref2_ll as a reference value at the time of light load. When the charge amount is larger, the reference voltage vref_2 has a second voltage value Vref2_hl as a reference value at the time of the heavy load. The first voltage value Vref2 LL is smaller than the second voltage value Vref2 HL.

In some examples shown in fig. 7, the i-th stage detection voltage VQG is shown on the line L1 when the power device 200 has a light load and no electrical abnormality of the leakage current occurs. The reference voltage Vref_2 has a voltage value Vref2_LL in response to the power device 200 having a light load. At this time, the voltage value of the i-th stage detection voltage VQG is lower than the voltage value Vref2 LL, and thus the comparison circuit 323 outputs the i-th stage detection signal S2 indicating that the power component 200 is damaged and operable.

The i-th stage detection voltage VQG is shown on the line L2 when the power device 200 has a heavy load and no electrical abnormality of leakage current occurs. The reference voltage Vref_2 has a voltage value Vref2_HL in response to the power component 200 having a reload. At this time, the voltage value of the i-th stage detection voltage VQG is lower than the voltage value Vref2 HL, and thus the comparison circuit 323 outputs the i-th stage detection signal S2 indicating that the power component 200 is damaged and operable. It should be noted that, in the known detection circuit, the comparison circuit outputs a detection signal of an error indication in consideration that the voltage value of the detection voltage is greater than the voltage value vref_1.

The i-th stage detection voltage VQG is shown on the line L3 when the power device 200 has a light load and an electrical abnormality of the leakage current occurs. The reference voltage Vref_2 has a voltage value Vref2_LL in response to the power device 200 having a light load. At this time, the voltage value of the i-th stage detection voltage VQG is higher than the voltage value Vref2 LL, and thus the comparison circuit 323 outputs the i-th stage detection signal S2 indicating that the power component 200 is damaged and inoperable.

The i-th stage detection voltage VQG is shown on the line L4 when the power device 200 has a heavy load and an electrical abnormality of the leakage current occurs. The reference voltage Vref_2 has a voltage value Vref2_HL in response to the power component 200 having a reload. At this time, the voltage value of the i-th stage detection voltage VQG is higher than the voltage value Vref2 HL, and thus the comparison circuit 323 outputs the i-th stage detection signal S2 indicating that the power component 200 is damaged and inoperable.

In summary, the current anomaly monitoring device and the current anomaly monitoring method according to the embodiments of the present invention determine whether the power device is damaged due to an overcurrent according to an output voltage, an output current and a control current of the power device in a multi-stage short circuit time, and determine whether an operation anomaly of a leakage current occurs after the power device is damaged. In this way, the current anomaly monitoring device can estimate the operation characteristics of the power component in different protection triggering safety times (i.e. short-circuit time), and can monitor the electrical operation (i.e. health) of the power component in real time. In some embodiments, the reference voltage is changed according to the load of the power component, so the comparison circuit can generate the detection signal based on the variable reference voltage, thereby improving the accuracy of detection.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and not for limiting the same; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the invention.

Claims (20)

1. A current anomaly monitoring device, adapted for use in a power assembly, comprising:

the first detection circuit is coupled with the power component and is used for detecting a first electrical parameter of the power component based on the ith-stage short circuit time;

The second detection circuit is coupled with the power component and is used for detecting a second electrical parameter of the power component based on the ith-stage short-circuit time to generate an ith-stage detection signal; and

The control circuit is coupled with the first detection circuit and the second detection circuit and is used for generating an ith grade heat predicted value according to the first electrical parameter to judge whether the power component is damaged or not and judging whether the power component is abnormal or not according to the ith grade detection signal,

Wherein the control circuit records the i-th stage heat predictive value and the i-th stage short-circuit time when the power component is judged to be damaged and abnormal in operation, and adjusts the i-th stage short-circuit time to be i+1-th stage short-circuit time when the power component is judged to be non-damaged and abnormal in operation, wherein i is a non-negative integer.

2. The current anomaly monitoring device of claim 1, wherein the first electrical parameter comprises an output current and an output voltage of the power component.

3. The current anomaly monitoring device of claim 2, wherein the control circuit receives the i-th stage heat predictive value generated by integrating the product of the output current and the output voltage based on the i-th stage short circuit time.

4. The current anomaly monitoring device of claim 1, wherein the control circuit determines the power component as damaged when the i-th stage heat predictive value is greater than a reference heat predictive value, wherein the reference heat predictive value is associated with a size of the power component.

5. The current anomaly monitoring device of claim 1, wherein the second electrical parameter comprises a control current of the power component.

6. The current anomaly monitoring device of claim 5, wherein the second detection circuit comprises:

the differential circuit is coupled with the control end of the power component and used for outputting the amplified control current according to the control current;

An integrating circuit coupled to the differential circuit for performing an integrating operation according to the amplified control current to generate an i-th stage detection voltage; and

The comparison circuit is coupled to the integration circuit and the control circuit and is used for comparing the ith detection voltage with a reference voltage to generate the ith detection signal.

7. The current anomaly monitoring device of claim 6, wherein the i-th stage detection signal has a first value to cause the control circuit to determine that the power component is not operating anomaly when the voltage value of the i-th stage detection voltage is not greater than the voltage value of the reference voltage, wherein the i+1-th stage short-circuit time is the i-th stage short-circuit time plus a reference short-circuit time.

8. The current anomaly monitoring device of claim 6, wherein the i-th stage detection signal has a second value when the voltage value of the i-th stage detection voltage is greater than the voltage value of the reference voltage, such that the control circuit determines that the power component is operating abnormally.

9. The current anomaly monitoring device of claim 6, wherein the second detection circuit adjusts a voltage value of the reference voltage according to a load of the power component.

10. The current anomaly monitoring device of claim 1, further comprising:

the driving circuit is coupled with the power component and the control circuit and is used for outputting control current to the control end of the power component; and

The short-circuit protection circuit is coupled to the power component, the first detection circuit and the second detection circuit and is used for judging whether to turn off the power component according to the ith detection signal.

11. A method for monitoring current anomalies, suitable for use in a power assembly, comprising:

detecting a first electrical parameter of the power component based on the ith stage short-circuit time through a first detection circuit;

detecting, by a second detection circuit, a second electrical parameter of the power component based on the ith stage short circuit time to generate an ith stage detection signal;

Judging whether the power component is damaged or not by a control circuit according to the first electrical parameter to generate an ith-stage heat predicted value, and judging whether the power component is abnormal or not according to the ith-stage detection signal;

Recording, by the control circuit, the i-th stage heat predictive value and the i-th stage short-circuit time when the power component is judged to be damaged and is abnormal in operation; and

And when the power component is judged to be non-damaged and is abnormal in non-operation, adjusting the ith stage short-circuit time to be the (i+1) th stage short-circuit time through the control circuit, wherein i is a non-negative integer.

12. The method of claim 11, wherein the first electrical parameter comprises an output current and an output voltage of the power component.

13. The current anomaly monitoring method of claim 12, wherein the step of generating an i-th stage heat predictive value based on the first electrical parameter to determine whether the power component is damaged and determining whether the power component is operating abnormally based on the i-th stage detection signal comprises:

And receiving, by the control circuit, the i-th stage heat predictive value generated by integrating the product of the output current and the output voltage based on the i-th stage short-circuit time.

14. The current anomaly monitoring method of claim 11, wherein the step of generating the i-th stage heat predictive value based on the first electrical parameter to determine whether the power component is damaged and determining whether the power component is operating abnormally based on the i-th stage detection signal comprises:

And judging the power component to be damaged when the i-th grade heat predicted value is larger than a reference heat predicted value through the control circuit, wherein the reference heat predicted value is related to the size of the power component.

15. The current anomaly monitoring method of claim 11, wherein the second electrical parameter comprises a control current of the power component.

16. The current anomaly monitoring method of claim 15, wherein detecting the second electrical parameter of the power component based on the i-th stage short circuit time to generate the i-th stage detection signal comprises:

outputting the amplified control current according to the control current by a differential circuit of a second detection circuit;

integrating, by an integrating circuit of a second detecting circuit, an integrating operation according to the amplified control current to generate an i-th stage detection voltage; and

And comparing the ith detection voltage with a reference voltage by a comparison circuit of a second detection circuit to generate the ith detection signal.

17. The current anomaly monitoring method of claim 16, wherein the step of generating an i-th stage heat predictive value based on the first electrical parameter to determine whether the power component is damaged and determining whether the power component is operating abnormally based on the i-th stage detection signal comprises:

When the voltage value of the ith detection voltage is not larger than the voltage value of the reference voltage, the ith detection signal has a first value, the control circuit judges that the power component is non-operation abnormal, wherein the ith+1st stage short-circuit time is the ith stage short-circuit time plus the reference short-circuit time.

18. The current anomaly monitoring method of claim 16, wherein the step of generating an i-th stage heat predictive value based on the first electrical parameter to determine whether the power component is damaged and determining whether the power component is operating abnormally based on the i-th stage detection signal comprises:

when the voltage value of the ith detection voltage is larger than the voltage value of the reference voltage, the ith detection signal has a second value, and the control circuit judges that the power component is abnormal in operation.

19. The current anomaly monitoring method of claim 11, further comprising:

And adjusting the voltage value of the reference voltage according to the load of the power component through the second detection circuit.

20. The current anomaly monitoring method of claim 11, further comprising:

And judging whether to turn off the power component according to the ith detection signal through a short-circuit protection circuit.