TWI831541B - Abnormal current monitoring device and abnormal current monitoring method - Google Patents

Abstract

An abnormal current monitoring device and an abnormal current monitoring method are provided. The abnormal current monitoring device includes a first detecting circuit, a second detecting circuit and a controlling circuit. The first detecting circuit detects a first electrical parameter of a power component based on an i-th stage short-circuit time. The second detecting circuit detects a second electrical parameter of the power component to generate an i-th stage detecting signal based on the i-th stage short-circuit time. The controlling circuit generates an i-th stage heat estimation according to the first electrical parameter, to determine whether the power component is broken, and determines whether the power component operates abnormally according to the i-th stage detecting signal, to record the i-th stage heat estimation and the i-th stage short-circuit time, or to adjust the i-th stage short-circuit time as an i+1-th stage short-circuit time.

Description

Current abnormality monitoring device and current abnormality monitoring method

The present invention relates to an electronic device, and in particular, to a current abnormality monitoring device and a current abnormality monitoring method.

In response to electronic products with different needs, these products can use various materials to manufacture power components. In order to meet the demand for miniaturization, the size of power components is getting smaller and smaller, and the response time of the power components to withstand instantaneous overcurrent is shortened. Within the preset reaction time, when the energy of the overcurrent is too large, the power components will be slightly damaged and the oxide layer in them will be destroyed. At this time, although the power element can operate, the power element will generate leakage current and affect the output power. On the other hand, when the energy of the overcurrent is greater, the power components will be severely damaged and unable to operate.

Generally speaking, overcurrent detection protection circuits can protect power components from serious damage by detecting overcurrent. However, the overcurrent detection protection circuit cannot know the damage of the power components, so it cannot eliminate the problem of electrical abnormalities.

Embodiments of the present invention provide a current abnormality monitoring device that can monitor electrical abnormalities of overcurrent and monitor the health of power components to eliminate electrical abnormality problems caused by leakage current.

The current abnormality monitoring device according to the embodiment of the present invention is suitable for power components. 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 to detect the first electrical parameter of the power component based on the i-th stage short circuit time. The second detection circuit is coupled to the power component. The second detection circuit is used to detect the second electrical parameter of the power component based on the i-th level short-circuit time to generate the i-th level detection signal. The control circuit is coupled to the first detection circuit and the second detection circuit. The control circuit is used to generate an i-th level heat estimate based on the first electrical parameter to determine whether the power component is damaged, and to determine whether the power component operates abnormally based on the i-th level detection signal. When the power component is judged to be damaged and operating abnormally, the control circuit records the i-th level heat estimate and the i-th level short-circuit time. When the power component is judged to be non-damaged and not operating abnormally, the control circuit adjusts the i-th level short-circuit time to the i+1-th level short-circuit time. i is an integer greater than or equal to zero.

An embodiment of the present invention also provides a current abnormality monitoring method. The current abnormality monitoring method is suitable for power components and includes the following steps. The first electrical parameter of the power component is detected based on the i-th stage short-circuit time through the first detection circuit. The second detection circuit detects the second electrical parameter of the power element based on the i-th level short-circuit time to generate an i-th level detection signal. The control circuit generates an i-th level heat estimate based on the first electrical parameter to determine whether the power component is damaged, and based on the i-th level detection signal No. to determine whether the power components are operating abnormally. When the power component is judged to be damaged and operating abnormally, the i-th level heat estimate and the i-th level short-circuit time are recorded through the control circuit. When the power component is judged to be non-damaged and not operating abnormally, the i-th level short-circuit time is adjusted to the i+1-th level short-circuit time through the control circuit. i is an integer greater than or equal to zero.

Based on the above, the current abnormality monitoring device and current abnormality monitoring method according to the embodiment of the present invention can detect different electrical parameters of the power components, and based on these electrical parameters, determine whether the power components are damaged due to electrical abnormalities due to overcurrent. And whether there is an electrical abnormality of leakage current that causes abnormal operation. In this way, the current abnormality monitoring device can monitor abnormal overcurrent and instantly monitor the health of the power components to eliminate various electrical abnormality problems.

In order to make the above-mentioned features and advantages of the present invention more obvious and easy to understand, embodiments are given below and described in detail with reference to the accompanying drawings.

100, 300: Current abnormality monitoring device

110, 310: first detection circuit

120, 320: Second detection circuit

130, 330: Control circuit

200:Power components

311:Oscilloscope

321: Differential circuit

322: Integral circuit

323: Comparison circuit

340: Drive circuit

350: Short circuit protection circuit

360:Signal Generator

400: Inductive load clamp circuit

S1: Electrical parameters

S2: detection signal

D1: Diode

ESC,tot: estimated heat value

ID: output current

IG: control current

IG’: amplified control current

L1:Inductor

L1~L4: Line

S210~S250: steps

S410~S460: Module

TSC: short circuit time

VDD: power supply voltage

Vref, Vref_1, Vref_2: reference voltage

VDS: output voltage

VQG: detection voltage

Vref_2_HL, Vref_2_LL: voltage value

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

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

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

Figure 4 is an illustration of the current abnormality monitoring method according to an embodiment of the present invention. Make a schematic diagram.

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

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

FIG. 7 is a schematic diagram of the operation of the second detection circuit according to the embodiment of FIG. 5 of the present invention.

Some embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The component symbols cited in the following description will be regarded as the same or similar components when the same component symbols appear in different drawings. These embodiments are only for the purpose of this disclosure. This part of the invention does not disclose all possible implementations of the invention. Rather, these embodiments are only examples within the scope of the patent application of the invention.

FIG. 1 is a block diagram of a current abnormality monitoring device according to an embodiment of the present invention. Referring to FIG. 1 , the current abnormality monitoring device 100 can be applied to the power component 200 to monitor various electrical abnormality problems of the power component 200 . In this embodiment, the power element 200 may be, for example, a Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET), an Insulated Gate Bipolar Transistor (IGBT), or a Silicon Carbide (SiC). ) or semiconductor components made of gallium nitride (GaN).

In this embodiment, the current abnormality monitoring device 100 can be connected to the power component 200 integrated on 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 (for example, the control circuit 130) and a read-only memory (ROM). ), random access memory (RAM), electronically erasable programmable read-only memory (EEPROM), flash memory and other memories to run operating systems and applications. In this embodiment, the chip can be applied to electrical testing devices of motors, power converters or power modules.

In the embodiment shown in FIG. 1 , the current abnormality 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 coupled to the power element 200 respectively. 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 component 200 .

In this embodiment, the control circuit 130 is coupled to the first detection circuit 110 and the second detection circuit 120 . The control circuit 130 can receive the data or signals (for example, the parameter S1 and the signal S2) detected by the first detection circuit 110 and the second detection circuit 120 respectively, and perform a judgment operation regarding electrical abnormalities accordingly. In this 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 devices. General-purpose or special-purpose microprocessors (Microprocessors), Digital Signal Processors (DSP), programmable controllers, special application integrated circuits (Application Specific Integrated Circuits (ASIC), Programmable Logic Device (PLD) or other similar devices or a combination of these devices, which can load and execute relevant firmware or software to implement computing and control functions.

FIG. 2 is a flow chart of a current abnormality monitoring method according to an embodiment of the present invention. Referring to FIG. 1 and FIG. 2 , the current abnormality monitoring device 100 may perform the following steps S210 to S250. In this embodiment, the current abnormality monitoring device 100 can repeatedly execute steps S210 to S240 to monitor and record the electrical operations of the power component 200 in response to different short-circuit times until the power component 200 is damaged and cannot operate and stops at step S250. . The following embodiment illustrates the steps of the i-th level monitoring operation of the current abnormality monitoring device 100, and takes the i-th level short-circuit time as an example, where i is an integer greater than or equal to zero.

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 this embodiment, the first electrical parameter S1 is an electrical parameter related to overcurrent, and may include, for example, the output current of the power element 200 (for example, the output current ID shown in FIG. 3 ) and the output voltage (for example, The output voltage VDS shown in Figure 3).

In step S220, the second detection circuit 120 detects the second electrical parameter of the power element 200 based on the i-th level short-circuit time to generate the i-th level detection signal S2. The second detection circuit 120 provides the i-th level detection signal S2 to the control circuit 130. In this embodiment, the second electrical parameter is an electrical parameter related to leakage current, and may include, for example, Including the control current of the power element 200 (for example, the control current IG shown in FIG. 3).

In step S230, the control circuit 130 generates an i-th level heat estimate according to the first electrical parameter S1 to determine whether the power element 200 is damaged. That is to say, the control circuit 130 converts the current and/or voltage (ie, the first electrical parameter S1) detected based on the i-th level short-circuit time into a heat parameter (ie, the i-th level heat estimate value), according to To determine whether the overcurrent causes damage to the power component 200 .

If the power element 200 is determined to be non-damaged, it means that the power element 200 can withstand this large current within the i-th level short-circuit time without any electrical abnormality of overcurrent occurring or not occurring. The current abnormality monitoring device 100 executes step S240 to continue monitoring. On the contrary, if the power element 200 is determined to be damaged, it means that the power element 200 cannot withstand the corresponding large current within the i-th level short-circuit time, and an electrical abnormality of overcurrent has occurred or will occur. The current abnormality monitoring device 100 executes step S250 to further monitor the health of the power component 200 .

In addition, in step S230, the control circuit 130 determines whether the power element 200 operates abnormally according to the i-th level detection signal S2. That is to say, the control circuit 130 analyzes the current and/or voltage detected based on the i-th level short-circuit time (ie, the i-th level detection signal S2), and determines based on whether the leakage current is too large to render the power element 200 inoperable.

If the power element 200 is determined to be non-operating abnormally, it means that the power element 200 can still operate even if it is damaged, and electrical abnormality of leakage current has not occurred or will not occur. Therefore, the control circuit 130 determines that the power element 200 is non-operating abnormal. The current abnormality monitoring device 100 executes step S240. On the contrary, if it is determined that the power component 200 is operating abnormally, It indicates that the power element 200 is damaged and cannot operate, and an electrical abnormality of leakage current has occurred or will occur. Therefore, the control circuit 130 determines that the power element 200 is operating abnormally. The current abnormality monitoring device 100 executes step S250.

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

In step S250, when the power element 200 is determined to be damaged and operates abnormally, the control circuit 130 records the i-th level heat estimation value and the i-th level short circuit time. That is to say, when the power component 200 is damaged and cannot operate, the current abnormality monitoring device 100 records electrical parameters that are sufficient to disable the power component 200 .

It is worth mentioning here that the current abnormality monitoring device 100 can determine whether an overcurrent occurs in the power element 200 based on multiple electrical parameters of the power element 200 (ie, the first electrical parameter S1 and the i-th level detection signal S2). Electrical abnormalities may cause damage, and whether electrical abnormalities such as leakage current may cause abnormal operation. Therefore, the current abnormality monitoring device 100 can estimate the protection triggering safety time (ie, short circuit time) of the power component 200 in response to overcurrent, and can real-time monitor the health and electrical abnormalities of the power component 200 .

FIG. 3 is a block diagram of a current abnormality monitoring device according to an embodiment of the present invention. Referring to FIG. 3 , the current abnormality monitoring device 300 may include a first detection circuit 310. The second detection circuit 320, the control circuit 330, the driving circuit 340 and the short circuit protection circuit 350. For the circuits 310 to 330 shown in Figure 3, reference can be made to the relevant description of the current abnormality monitoring device 100 shown in Figure 1 and by analogy, and will not be repeated here. In order to facilitate the explanation of the content of this case, the labeling and description of the resistors are omitted in Figure 3.

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

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

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

In some embodiments, the current abnormality 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 can generate the pulse wave signal (ie, the control current IG) as described above, and output the pulse wave signal to the power element 200 through the driving circuit 340 . In one embodiment, the signal generator 360 may be integrated with the driving circuit 340 .

In some embodiments, the oscilloscope 311 is coupled to two ends of the power component 200 . The oscilloscope 311 can detect the output voltage VDS and the output current ID of the power component 200 to cooperate with the first detection circuit 310 . In one embodiment, the oscilloscope 311 can be integrated with the first detection circuit 310 .

FIG. 4 is an operational schematic diagram of a current abnormality monitoring method according to an embodiment of the present invention. Referring to FIG. 3 and FIG. 4 , the current abnormality monitoring device 300 can execute the following modules S410 to S460. In this embodiment, the current abnormality monitoring device 300 can repeatedly execute the modules S410 to S440 to monitor and record the electrical operations of the power component 200 in response to different short-circuit times until the power component 200 is damaged and cannot operate and stops in the mode. Group S460.

In module S410, the user can operate the current abnormality monitoring device 300 to set the 0th level output voltage VDS and the 0th level short circuit time TSC. That is to say, the user can set the initial operating parameters of the current abnormality monitoring device 300 . In some embodiments, the level 0 output voltage VDS and the level 0 short circuit time TSC may be the current The abnormality monitoring device 300 has preset parameters when it leaves the factory. The following embodiment illustrates the steps of the i-th level monitoring operation of the current abnormality monitoring device 300, and takes the i-th level short-circuit time as an example, where i is an integer greater than or equal to zero.

In module S420, the control circuit 330 receives the output current ID and the output voltage VD (ie, the first electrical parameter S1) from the first detection circuit 310. The control circuit 330 determines whether the power element 200 is damaged according to the aforementioned parameter S1. Another implementation detail of step S230 in FIG. 2 is illustrated by an example and is illustrated with a two-dimensional diagram. In the illustration of the module S420, the horizontal axis is the operation time of the current abnormality monitoring device 300 (the unit is, for example, microseconds (μs)), and the vertical axis is the voltage value, current value, and heat value (or energy value).

In detail, the control circuit 330 receives the i-th level heat estimation value ESC,tot generated by integrating the product of the output current ID and the output voltage VDS based on the i-th level short-circuit time TSC. In this embodiment, the aforementioned integral calculation may be performed, for example, by the control circuit 330 . In some embodiments, the aforementioned integral calculation may be performed, for example, by other calculation circuits. Other calculation circuits can obtain the waveform signals of the output current ID and the output voltage VDS through the oscilloscope 311 and perform integral calculations accordingly.

In this embodiment, the aforementioned integral calculation includes the following operations. The control circuit 330 converts the output current ID and the output voltage VDS into digital data through an analog to digital converter (Analog to Digital), and performs operations based on relevant firmware or software. Digital points. The i-th level heat estimation value ESC,tot can be implemented as shown in the following formula (1). ESC in formula (1) is the estimated heat value ESC,tot of the i-th stage, TSC is the short-circuit time TSC of the i-th stage, VDS is the voltage value of the output voltage VDS, and ID is the output Current value of current ID, t is time.

That is to say, during the i-th stage short-circuit time TSC when the power element 200 reacts, the control circuit 330 accumulates the energy formed by the output current ID and the output voltage VDS. The control circuit 330 converts the aforementioned energy into heat (ie, the i-th level heat estimate value ESC,tot) with a preset efficiency (eg, close to 100%).

Continuing from the above description, the control circuit 330 compares the i-th level heat estimate value ESC,tot with the reference heat estimate value to determine whether the power component 200 is damaged. In this embodiment, when the i-th level heat estimation value ESC,tot is greater than the reference heat estimation value, it means that the i-th level heat estimation value ESC,tot is too large and overcurrent has occurred or will occur in the power element 200. Electrical abnormalities. At this time, the control circuit 330 determines that the power element 200 is damaged. The current abnormality monitoring device 300 executes module S430.

On the other hand, when the i-th level heat estimation value ESC,tot is not greater than the reference heat estimation value, it means that the i-th level heat estimation value ESC,tot is not enough to cause an electrical abnormality of overcurrent in the power element 200 . At this time, the control circuit 330 determines that the power element 200 is not damaged. The current abnormality monitoring device 300 re-executes the module S420.

In this embodiment, the reference heat estimate value refers to the maximum energy that the power component 200 can withstand. When the energy applied to the power component 200 is higher than the reference heat estimate, at least a part of the power component 200 (such as the crystal surface or its oxide layer) will be damaged. In this embodiment, the reference heat estimate value is associated with the size of the power component 200 . The reference heat estimate may be, for example, the unit energy provided in advance by the manufacturer of the power component 200 , or parameters obtained by experiments conducted by a third-party manufacturer.

In module S430, the control circuit 330 determines that the power component 200 is damaged. At the same time, the second detection circuit 320 generates the i-th level detection signal S2 according to the control current IG, so that the control circuit 330 further determines whether the power element 200 operates abnormally based on the i-th level detection signal S2. To illustrate the steps in FIG. 2 S220 and another implementation detail of step S230.

In detail, please refer to FIG. 5 , which is a circuit diagram of the second detection circuit according to the embodiment of FIG. 3 of the present invention. In this embodiment, the second detection circuit 320 may include a differential circuit 321, an integrating circuit 322 and a comparison circuit 323. The differential input terminal of the differential circuit 321 is coupled to the control terminal of the power element 200 to capture the control current IG. The inverting input terminal of the integrating circuit 322 is coupled to the output terminal of the differential circuit 321 . The non-inverting input terminal of the integrating circuit 322 is coupled to the ground terminal. The inverting input terminal of the comparison circuit 323 is coupled to the output terminal of the integrating circuit 322 . The non-inverting input terminal of the comparison circuit 323 receives the 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 . In order to facilitate the explanation of the contents of this case, the labels and descriptions of resistors and capacitors are omitted in Figure 5.

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

In this embodiment, when the voltage value of the i-th level detection voltage VQG is not greater than the voltage value of the reference voltage Vref, it means that the leakage current of the power element 200 is not greater than the reference leakage current. That is, even if the power element 200 is damaged due to overcurrent, the power element 200 can still operate. At this time, the comparison circuit 323 generates the i-th level 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 aforementioned i-th level detection signal S2 may indicate that the power element 200 is damaged and operable, so that the control circuit 330 determines that there is no operating abnormality. The current abnormality monitoring device 300 executes module S440.

On the other hand, when the voltage value of the i-th level detection voltage VQG is greater than the voltage value of the reference voltage Vref, it means that the leakage current of the power element 200 is greater than the reference leakage current. That is to say, in addition to being damaged by overcurrent, the health of the power element 200 is low and an excessive leakage current is generated. At this time, the comparison circuit 323 generates the i-th level detection signal S2 with the second value. The second value may be, for example, a high voltage reference level or a logic high level. The aforementioned i-th level detection signal S2 may indicate that the power component 200 is damaged and cannot operate, so that the control circuit 330 determines that the power component 200 operates abnormally. The current abnormality monitoring device 300 executes module S450.

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

In module S450, when the power element 200 is determined to be damaged and operates abnormally, the control circuit 330 draws a table or a two-dimensional legend based on the data in the 0th-level monitoring operation to the i-th level monitoring operation. In the illustration of the module S450, the horizontal axis is the voltage value of the output voltage VDS, and the vertical axis is the short-circuit time TSC of the current abnormality monitoring device 300 (the unit is, for example, μs).

In detail, the control circuit 330 records the estimated heat value ESC, tot and the output current ID of the power component 200 in various levels of monitoring operations, and uses the output voltage VDS and the short-circuit time TSC as variables to obtain the legend shown in module S450. Therefore, the control circuit 330 can obtain the electrical operating characteristics of the power component 200 in response to various short-circuit times TSC, such as over-current tolerance and corresponding voltage values, current values, etc.

In module S460, the control circuit 330 can access data such as tables or two-dimensional legends recorded in module S450. The aforementioned data is, for example, the estimated heat value ESC, tot and the short-circuit time TSC of the power component 200 in various levels of monitoring operations. In some embodiments, the table or two-dimensional legend recorded in the module S450 can be used as an electrical operation reference for the power component 200 and other components with the same specifications, so as to be applied in the protection circuit of the power component 200 .

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

Referring to FIGS. 5 to 7 , in some conventional detection circuits, the comparison circuit performs comparison operations based on the 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 charge amounts, or when the comparison circuit operates at any point in time, the comparison circuit uses the same reference value as the comparison basis. However, when the power element 200 is subjected to different loads, the charge or voltage on the non-inverting input terminal of the comparison circuit (corresponding to the detection voltage VQG in FIG. 5 ) has different corresponding values, so that the comparison circuit outputs a false comparison result.

In this embodiment, the smaller the voltage value of the i-th level detection voltage VQG, the smaller the amount of charge on this node, and the smaller the corresponding current value of the leakage current. The smaller the current value of the leakage current, the smaller the load the power element 200 bears (ie, light load), or the smaller the voltage value of the power supply voltage VDD (for example, 400V). On the other hand, the greater the voltage value of the i-th level detection voltage VQG, the greater the amount of charge on this node, and the greater the corresponding current value of the leakage current. The larger the current value of the leakage current, the larger the load the power element 200 bears (ie, heavy load), or the larger the voltage value of the power supply voltage VDD (for example, 800V).

It should be noted that the second detection circuit 320 or the control circuit 330 can 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 FIG. 6 Reference voltage Vref_2. In Figure 6, when the charge amount is smaller, the reference voltage Vref_2 has a first voltage value Vref2_LL, as a reference value at light load. When the amount of charge is larger, the reference voltage Vref_2 has a second voltage value Vref2_HL as a reference value during overloading. The first voltage value Vref2_LL is smaller than the second voltage value Vref2_HL.

In some examples as shown in FIG. 7 , assuming that the power element 200 has a light load and no electrical abnormality of leakage current occurs, the i-th level detection voltage VQG is exemplarily shown on the line L1 . In response to the light load of the power device 200, the reference voltage Vref_2 has a voltage value Vref2_LL. At this time, the voltage value of the i-th level detection voltage VQG is lower than the voltage value Vref2_LL, so the comparison circuit 323 outputs the i-th level detection signal S2 indicating that the power element 200 is damaged and operable.

Assuming that the power element 200 has a heavy load and no electrical abnormality of leakage current occurs, the i-th level detection voltage VQG is exemplarily shown on the line L2. In response to the heavy load of the power element 200, the reference voltage Vref_2 has a voltage value Vref2_HL. At this time, the voltage value of the i-th level detection voltage VQG is lower than the voltage value Vref2_HL, so the comparison circuit 323 outputs the i-th level detection signal S2 indicating that the power element 200 is damaged and operable. It should be noted that in the conventional detection circuit, the comparison circuit will consider that the voltage value of the detection voltage is greater than the voltage value Vref_1 and output a detection signal indicating an error.

Assuming that the power element 200 has a light load and an electrical abnormality of leakage current occurs, the i-th level detection voltage VQG is exemplarily shown on the line L3. In response to the light load of the power device 200, the reference voltage Vref_2 has a voltage value Vref2_LL. At this time, the voltage value of the i-th level detection voltage VQG is higher than the voltage value Vref2_LL, so the comparison circuit 323 outputs the i-th level detection signal S2 indicating that the power element 200 is damaged and cannot operate.

Assuming that the power component 200 is heavily loaded and electrical abnormality occurs due to leakage current, The i-th level detection voltage VQG is exemplarily shown on line L4. In response to the heavy load of the power element 200, the reference voltage Vref_2 has a voltage value Vref2_HL. At this time, the voltage value of the i-th level detection voltage VQG is higher than the voltage value Vref2_HL, so the comparison circuit 323 outputs the i-th level detection signal S2 indicating that the power element 200 is damaged and cannot operate.

To sum up, the current abnormality monitoring device and current abnormality monitoring method according to the embodiment of the present invention determine whether the power element is damaged due to overcurrent based on the output voltage, output current and control current of the power element in response to the multi-level short circuit time. , and determine whether abnormal operation of leakage current occurs after power components are damaged. In this way, the current abnormality monitoring device can estimate the operating characteristics of the power component within different protection triggering safety times (ie, short circuit time), and can also monitor the electrical operation (ie, health) of the power component in real time. In some embodiments, the reference voltage changes in response to the load of the power component, so the comparison circuit can generate a detection signal based on the variable reference voltage, thereby improving detection accuracy.

Although the present invention has been disclosed above through embodiments, they are not intended to limit the present invention. Anyone with ordinary knowledge in the technical field may make some modifications and modifications without departing from the spirit and scope of the present invention. Therefore, The protection scope of the present invention shall be determined by the appended patent application scope.

S210~S250: steps

Claims (20)

A current abnormality monitoring device suitable for power components, including: a first detection circuit coupled to the power component for detecting the first electrical parameter of the power component based on the i-th level short circuit time; a second detection circuit , coupled to the power element, for detecting the second electrical parameter of the power element to generate an i-th level detection signal based on the i-th level short-circuit time; and a control circuit, coupled to the first detection circuit and the second detection circuit, used to generate an i-th level heat estimate based on the first electrical parameter to determine whether the power component is damaged, and to determine the i-th level detection signal based on the Whether the power element operates abnormally, wherein when the power element is judged to be damaged and operates abnormally, the control circuit records the i-th stage heat estimate value and the i-th stage short circuit time, and when the power element When it is determined that there is no damage and no abnormal operation, the control circuit adjusts the i-th level short-circuit time to the i+1-th level short-circuit time, where i is an integer greater than or equal to zero. The current abnormality monitoring device according to claim 1, wherein the first electrical parameter includes an output current and an output voltage of the power component. The current abnormality monitoring device according to claim 2, wherein the control circuit receives the i-th level generated by integrating the product of the output current and the output voltage based on the i-th level short-circuit time. Calorie estimate. The current abnormality monitoring device according to claim 1, wherein when the i-th level heat estimate value is greater than a reference heat estimate value, the control circuit determines that the power element is damaged, wherein the reference heat estimate value The value is related to the size of the power element. The current abnormality monitoring device according to claim 1, wherein the second electrical parameter includes the control current of the power component. The current abnormality monitoring device according to claim 5, wherein the second detection circuit includes: a differential circuit coupled to the control end of the power element 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 the i-th level detection voltage; and a comparison circuit, coupled to the integrating circuit and the control circuit, for The i-th level detection voltage is compared with a reference voltage to generate the i-th level detection signal. The current abnormality monitoring device according to claim 6, wherein when the voltage value of the i-th level detection voltage is not greater than the voltage value of the reference voltage, the i-th level detection signal has a first value, so that the i-th level detection signal has a first value. The control circuit determines that the power element is non-operationally abnormal, wherein the i+1-th level short-circuit time is the i-th level short-circuit time plus a reference short-circuit time. The current abnormality monitoring device according to claim 6, wherein when the voltage value of the i-th level detection voltage is greater than the voltage value of the reference voltage, the i-th level detection voltage The detection signal has a second value, so that the control circuit determines that the power component operates abnormally. The current abnormality monitoring device of claim 6, wherein the second detection circuit adjusts the voltage value of the reference voltage according to the load of the power component. The current abnormality monitoring device according to claim 1, further comprising: a drive circuit coupled to the power element and the control circuit for outputting a control current to the control end of the power element; and a short-circuit protection circuit, coupled to The power element, the first detection circuit and the second detection circuit are connected to determine whether to turn off the power element according to the i-th level detection signal. A current abnormality monitoring method, suitable for power components, including: detecting the first electrical parameter of the power component based on the i-th level short-circuit time through a first detection circuit; using a second detection circuit, based on the i-th level short-circuit time During the short circuit time, the second electrical parameter of the power component is detected to generate the i-th level detection signal; through the control circuit, the i-th level heat estimation value is generated according to the first electrical parameter to determine whether the power component is Damage, and determine whether the power element operates abnormally according to the i-th level detection signal; when the power element is determined to be damaged and operates abnormally, the i-th level heat estimate is recorded through the control circuit And the i-th stage short circuit time; and when the power component is judged to be non-damaged and non-operating abnormal, through the A control circuit that adjusts the i-th level short-circuit time to the i+1-th level short-circuit time, where i is an integer greater than or equal to zero. The current abnormality monitoring method according to claim 11, wherein the first electrical parameter includes the output current and output voltage of the power component. The current abnormality monitoring method according to claim 12, wherein the i-th level heat estimate is generated according to the first electrical parameter to determine whether the power element is damaged and the i-th level detection signal is used to determine whether the power element is damaged. The step of determining whether the power element operates abnormally includes: receiving, through the control circuit, the i-th level heat predetermined value generated by integrating the product of the output current and the output voltage based on the i-th level short-circuit time. Valuation. The current abnormality monitoring method according to claim 11, wherein the i-th level heat estimate is generated according to the first electrical parameter to determine whether the power element is damaged and the i-th level detection signal is used to determine whether the power element is damaged. The step of determining whether the power element operates abnormally includes: using the control circuit, when the i-th level heat estimate value is greater than a reference heat estimate value, determining that the power element is damaged, wherein the reference heat estimate value The value is related to the size of the power element. The current abnormality monitoring method according to claim 11, wherein the second electrical parameter includes the control current of the power component. The current abnormality monitoring method according to claim 15, wherein based on the i-th level short-circuit time, the step of detecting the second electrical parameter of the power element to generate the i-th level detection signal includes: The differential circuit of the second detection circuit outputs the amplified control current according to the control current; the integrating circuit of the second detection circuit performs an integration operation according to the amplified control current to generate the i-th level detection voltage; And through the comparison circuit of the second detection circuit, the i-th level detection voltage and the reference voltage are compared to generate the i-th level detection signal. The current abnormality monitoring method according to claim 16, wherein the i-th level heat estimate is generated according to the first electrical parameter to determine whether the power element is damaged and the i-th level detection signal is used to determine whether the power element is damaged. The step of determining whether the power element operates abnormally includes: when the voltage value of the i-th level detection voltage is not greater than the voltage value of the reference voltage, the i-th level detection signal has a first value, and the control circuit determines whether the The power element is non-operationally abnormal, and the i+1-th level short-circuit time is the i-th level short-circuit time plus a reference short-circuit time. The current abnormality monitoring method according to claim 16, wherein the i-th level heat estimate is generated according to the first electrical parameter to determine whether the power element is damaged and the i-th level detection signal is used to determine whether the power element is damaged. The step of determining whether the power component operates abnormally includes: when the voltage value of the i-th level detection voltage is greater than the voltage value of the reference voltage When , the i-th level detection signal has a second value, and the control circuit determines that the power element is operating abnormally. The current abnormality monitoring method according to claim 16, further comprising: adjusting the voltage value of the reference voltage according to the load of the power component through the second detection circuit. The current abnormality monitoring method as described in claim 11 further includes: outputting a control current to the control end of the power component through a drive circuit; and using a short-circuit protection circuit to determine whether to shut down based on the i-th level detection signal. The power components.

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