Monitoring circuit, monitoring method and power system for controlling switch

Abstract

The present application provides a monitoring circuit, a monitoring method and a power system for a control switch, wherein the control switch includes a first bridge arm and a second bridge arm coupled in parallel to each other, the monitoring circuit is coupled to the control switch, wherein the monitoring circuit includes: a state acquisition circuit, which acquires a characteristic signal of the control switch and sends a feedback signal according to the characteristic signal; a control circuit, the control circuit is coupled to the state acquisition circuit, determines the working state of the control switch according to the feedback signal, and when the working state of the control switch is abnormal, locates the first bridge arm or the second bridge arm with an abnormal working state, and configures the other bridge arm with a normal working state to be turned on. Through the above method, the working state of the control switch can be monitored in real time, the reliability and stability of the control switch can be improved, the monitoring circuit has a simple structure, and is conducive to reducing production costs and maintenance costs.

Description

Technical Field

[0001] The present application relates to the technical field of electronic circuits, and in particular to a monitoring circuit, a monitoring method and a power system. Background Art

[0002] In power electronic systems such as frequency converters, inverters and power drive systems, control switches are provided to dynamically adjust power supply according to circuit requirements to achieve intelligent control of the power system.

[0003] When the control switch works under high voltage, high current and high frequency switching conditions, its reliability and stability are crucial to the entire power system. Summary of the invention

[0004] The present application provides a monitoring circuit, a monitoring method and a power system for a control switch, which can monitor the working status of the control switch in real time, improve the reliability and stability of the control switch, and the monitoring circuit has a simple structure, which is conducive to reducing production costs and maintenance costs.

[0005] In order to solve the above technical problems, the first aspect of the present application provides a monitoring circuit for a control switch, wherein the control switch includes a first bridge arm and a second bridge arm coupled in parallel with each other, and the monitoring circuit is coupled to the control switch, and the monitoring circuit includes: a state acquisition circuit, which acquires a characteristic signal of the control switch and sends a feedback signal according to the characteristic signal; a control circuit, which is coupled to the state acquisition circuit, determines the working state of the control switch according to the feedback signal, and when the working state of the control switch is abnormal, locates the first bridge arm or the second bridge arm with an abnormal working state, and configures the other bridge arm with a normal working state to be turned on.

[0006] Among them, the state acquisition circuit is coupled to the first bridge arm, or coupled to the second bridge arm, or coupled to the first bridge arm and the second bridge arm respectively; the state acquisition circuit collects the characteristic signal of the corresponding bridge arm and sends a feedback signal according to the characteristic signal.

[0007] Among them, the state acquisition circuit includes a data processing chip, a sub-acquisition circuit and a sub-transmission circuit, and the acquisition pins of the sub-acquisition circuit and the data processing chip are coupled to each other; the data processing chip generates a feedback signal according to the characteristic signal collected by the sub-acquisition circuit; the signal pins of the sub-transmission circuit and the data processing chip are coupled to each other; and the sub-transmission circuit sends a feedback signal.

[0008] Among them, the sub-collection circuit includes a voltage-dividing structure and a collection structure, and the voltage-dividing structure includes at least one voltage-dividing resistor; the collection structure is coupled to the data processing chip, and the data processing chip collects the electrical signal of the collection structure to obtain a characteristic signal.

[0009] Among them, the state acquisition circuit includes a filter structure, the filter structure is coupled to the data processing chip, and the filter structure includes at least one capacitor; the filter structure is used to filter and reduce noise on the characteristic signal and / or feedback signal.

[0010] In order to solve the above technical problems, the second aspect of the present application provides a monitoring method based on a monitoring circuit of a control switch, wherein the control switch includes a first bridge arm and a second bridge arm coupled in parallel to each other, the monitoring circuit includes a state acquisition circuit and a control circuit coupled to each other, the monitoring circuit is coupled to the control switch, and the monitoring method includes:

[0011] The state acquisition circuit acquires the characteristic signal of the control switch and sends a feedback signal according to the characteristic signal; the control circuit determines the working state of the control switch according to the feedback signal; in response to the working state of the control switch being abnormal, the first bridge arm or the second bridge arm with the abnormal working state is located, and the other bridge arm with a normal working state is configured to be turned on.

[0012] Among them, the state acquisition circuit is coupled to the first bridge arm, or coupled to the second bridge arm, or coupled to the first bridge arm and to the second bridge arm respectively; the state acquisition circuit acquires the characteristic signal of the control switch, and the step of sending a feedback signal according to the characteristic signal includes: the state acquisition circuit acquires the characteristic signal of the corresponding bridge arm, and sends a feedback signal according to the characteristic signal.

[0013] Among them, the step of the control circuit determining the working state of the control switch according to the feedback signal includes: the control circuit collects the electrical signal of the control switch input voltage, and in response to the feedback signal and the electrical signal not meeting the preset working range, determines that the working state of the control switch is an abnormal state.

[0014] Among them, the state acquisition circuit includes a data processing chip, a sub-acquisition circuit and a sub-transmission circuit; the state acquisition circuit acquires the characteristic signal of the control switch, and the steps of sending a feedback signal according to the characteristic signal include: the sub-acquisition circuit acquires the characteristic signal of the control switch; the data processing chip generates a feedback signal according to the characteristic signal; and the feedback signal is sent through the sub-transmission circuit.

[0015] Among them, in response to the control switch working state being abnormal, the first bridge arm or the second bridge arm is located as the one with abnormal working state, and the step of configuring the other bridge arm with normal working state to be turned on includes: in response to the control switch working state being abnormal, configuring the control switch to gradually reduce the input current for slow shutdown protection; locating the first bridge arm or the second bridge arm as the one with abnormal working state, and configuring the other bridge arm with normal working state to be turned on.

[0016] To solve the above technical problems, the third aspect of the present application provides an electric power system, wherein the electric power system includes a monitoring circuit and a control switch, the control switch includes a first bridge arm and a second bridge arm coupled in parallel to each other, and the monitoring circuit is any one of the above monitoring circuits.

[0017] Different from the prior art, the present application provides a monitoring circuit, monitoring method and power system for a control switch, which can monitor the working state of the control switch in real time, so that the circuit where the control switch is located can select a suitable safe path between the first bridge arm and the second bridge arm, and can better withstand the working environment of high current and voltage. The reliability and stability of the control switch are improved, which is convenient for fault finding and circuit protection. The monitoring circuit structure is simple, and the switch in abnormal working state can be judged more accurately, which is conducive to reducing production and maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of an implementation scheme of a monitoring circuit for controlling a switch of the present application;

[0019] Figure 2 It is a structural schematic diagram of another implementation of the monitoring circuit of the control switch of the present application;

[0020] Figure 3 It is a structural schematic diagram of another implementation mode of a monitoring circuit for controlling a switch of the present application;

[0021] Figure 4 It is a structural schematic diagram of another implementation mode of the monitoring circuit of the control switch of the present application;

[0022] Figure 5 It is a structural schematic diagram of a specific embodiment of another implementation mode of the monitoring circuit of the control switch of the present application;

[0023] Figure 6 It is a flow chart of an implementation method of a monitoring circuit based on a control switch of the present application;

[0024] Figure 7 It is a flow chart of another embodiment of a monitoring method of a monitoring circuit based on a control switch of the present application;

[0025] Figure 8 It is a flow chart of another embodiment of a monitoring method of a monitoring circuit based on a control switch of the present application;

[0026] Fig. 9 It is a structural schematic diagram of an implementation method of a power system of the present application. DETAILED DESCRIPTION

[0027] The scheme of the embodiment of the present application is described in detail below in conjunction with the drawings of the specification.

[0028] In the following description, for the purpose of explanation rather than limitation, specific details such as specific system structures, interfaces, and technologies are provided to facilitate a thorough understanding of the present application.

[0029] The term "and / or" in this article is only a description of the association relationship of the associated objects. There can be three kinds of relationships. For example, A and / or B can be: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally means that the associated objects before and after are in an "or" relationship.

[0030] Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Fig. 9 The monitoring circuit and power system of the control switch in the figure are schematic diagrams of circuit logic, and the specific circuit structure is based on the circuit structure of actual production.

[0031] The present application first provides a monitoring circuit for a control switch, wherein the monitoring circuit for the control switch of the present application can monitor the working state of the control switch and control the control switch.

[0032] See also Figure 1 , Figure 1 It is a structural schematic diagram of an implementation scheme of a monitoring circuit for controlling a switch of the present application.

[0033] The control switch 11 includes a first bridge arm 111 and a second bridge arm 112 coupled in parallel to each other, and the monitoring circuit 12 is coupled to the control switch 11 .

[0034] The control switch 11 may be a circuit structure composed of a plurality of power semiconductor devices, and is widely used in power electronic systems, such as frequency converters, inverters, and electric drive systems.

[0035] In order to ensure the reliability of circuit operation, a first bridge arm 111 and a second bridge arm 112 are provided in the circuit of each phase of the three-phase electricity. When an abnormality occurs in the phase voltage, the monitoring circuit 12 is used to identify and locate the abnormality, and the correct current safety path is selected to ensure the normal operation of the circuit.

[0036] The monitoring circuit 12 includes: a state acquisition circuit 13, which acquires a characteristic signal of the control switch 11 and sends a feedback signal according to the characteristic signal; a control circuit 14, which is coupled to the state acquisition circuit 13, determines the working state of the control switch 11 according to the feedback signal, and when the working state of the control switch 11 is abnormal, locates the first bridge arm 111 or the second bridge arm 112 with an abnormal working state, and configures the other bridge arm with a normal working state to be turned on.

[0037] The monitoring circuit 12 can be multiplexed in the circuit structure, or can be separately set in other embodiments. In a high-voltage, high-current circuit, the monitoring circuit 12 monitors the control switch 11, effectively monitors the working state of the control switch 11, and enables the control switch 11 to be turned on or off at an appropriate time, thereby protecting the circuit.

[0038] In a specific implementation, a monitoring circuit 12 is provided in the circuit of each phase of the three-phase electricity to monitor the control switch 11 of each phase of the three-phase electricity. In other implementation circuits, only one monitoring circuit 12 may be provided to uniformly monitor the control switch 11 of the three-phase circuit. The characteristic signal of the control switch 11 may be a current or voltage signal flowing through the control switch 11. The current magnitude or current direction, or voltage magnitude, is detected. After the state acquisition circuit 13 processes the characteristic signal, such as modulation and demodulation, a feedback signal is generated. The feedback signal may also be a current or voltage signal generated by the state acquisition circuit 13. The feedback signal is then sent to the control circuit 14 to determine the working state of the control switch 11.

[0039] When the control switch 11 is in an abnormal working state, it is protectively shut down, the current passing through the control switch 11 is gradually reduced, and then the bridge arm in a normal working state is configured to be turned on.

[0040] See also Figure 2 , Figure 2 It is a structural schematic diagram of another implementation of the monitoring circuit of the control switch of the present application.

[0041] The monitoring circuit 12 of the control switch 11 includes: the control switch 11 includes a first bridge arm 111 and a second bridge arm 112 coupled to each other in parallel, and the monitoring circuit 12 is coupled to the control switch 11 .

[0042] The control switch 11 may be a circuit structure composed of several power semiconductor devices, which is widely used in power electronic systems, such as frequency converters, inverters, and power drive systems. In a specific embodiment, the control switch 11 may be an IGBT (Insulated Gate Bipolar Transistor), which has an emitter, a base, and a collector. When a positive collector voltage V is applied to the emitter, CE , and a positive gate voltage V is applied to the emitter. GE When the IGBT is turned on, the collector and emitter are conducting, and the collector current I flows C , realizing the function of controlling switch 11.

[0043] When the control switch 11 is in a saturated conduction state during normal operation, its conduction voltage VCE is low. If a fault occurs in the circuit where the control switch 11 is located, the current changes sharply, V CE It will rise or fall rapidly. If it cannot be handled in time, the circuit may be damaged due to overload and other reasons.

[0044] In order to ensure the reliability of circuit operation, a first bridge arm 111 and a second bridge arm 112 are provided in the circuit of each phase of the three-phase electricity. When an abnormality occurs in the phase voltage, the monitoring circuit 12 is used to identify and locate the abnormality, and the correct current safety path is selected to ensure the normal operation of the circuit.

[0045] In a specific embodiment, the monitoring circuit 12 includes: a state acquisition circuit 13, which acquires a characteristic signal of the control switch 11 and sends a feedback signal according to the characteristic signal; a control circuit 14, which is coupled to the state acquisition circuit 13, determines the working state of the control switch 11 according to the feedback signal, and when the working state of the control switch 11 is abnormal, locates the first bridge arm 111 or the second bridge arm 112 with an abnormal working state, and configures the other bridge arm with a normal working state to be turned on.

[0046] The monitoring circuit 12 can be multiplexed in the circuit structure, and in other embodiments, can also be set separately. In a high-voltage, high-current circuit, the monitoring circuit 12 monitors the control switch 11, effectively monitors the working state of the control switch 11, so that the control switch 11 can be turned on or off at the appropriate time to protect the circuit.

[0047] In a specific implementation, a monitoring circuit 12 is provided in the circuit of each phase of the three-phase electricity to monitor the control switch 11 of each phase of the three-phase electricity. In other implementation circuits, only one monitoring circuit 12 may be provided to uniformly monitor the control switch 11 of the three-phase circuit. The characteristic signal of the control switch 11 may be a current or voltage signal flowing through the control switch 11. The current magnitude or current direction, or voltage magnitude, is detected. After the state acquisition circuit 13 processes the characteristic signal, such as modulation and demodulation, a feedback signal is generated. The feedback signal may also be a current or voltage signal generated by the state acquisition circuit 13. The feedback signal is then sent to the control circuit 14 to determine the working state of the control switch 11.

[0048] When the control switch 11 is in an abnormal working state, it is protectively shut down, the current passing through the control switch 11 is gradually reduced, and then the bridge arm in a normal working state is configured to be turned on.

[0049] In a specific implementation, the state acquisition circuit 13 includes a data processing chip 131 , a sub-acquisition circuit 132 , and a sub-transmission circuit 133 .

[0050] The sub-acquisition circuit 132 is coupled to the acquisition pin of the data processing chip 131; the data processing chip 131 generates a feedback signal according to the characteristic signal collected by the sub-acquisition circuit 132; the sub-transmission circuit 133 is coupled to the signal pin of the data processing chip 131; the sub-transmission circuit 133 sends a feedback signal.

[0051] In a specific embodiment, see Figure 3 , Figure 3 FIG. 1 is a structural diagram of another embodiment of a monitoring circuit for controlling a switch of the present application. Figure 3 As shown, the data processing chip 131 is a 16-pin isolation driver chip, with pins 1-8 connected to the high voltage side and pins 9-16 connected to the low voltage side. An isolation barrier is provided inside to provide electrical isolation to prevent direct electrical connection between the high voltage side and the low voltage side. The acquisition pin uses a 1-pin AIN pin, and the signal pin is a 16-pin PWM pin.

[0052] The data processing chip 131 also includes a VDD pin (not marked in the figure) and a VCC pin (not marked in the figure). The data processing chip 131 provides power to different parts inside the data processing chip 131 through the VDD pin and the VCC pin. A transformer (not marked in the figure) is provided between the VDD pin and the AIN pin, indicating that the AIN pin is logically connected to the built-in constant current source.

[0053] In a specific implementation, the acquisition pins respectively acquire the voltage of the negative busbar output of each phase of the three-phase power, collect the feedback signal through the acquisition pins, and then send the feedback signal through the signal pins. Specifically, the characteristic signal V detected by the AIN pin AIN Can reflect the collector-emitter voltage V of the control switch 11 CE , the PWM input signal is converted into a signal suitable for transmission through the isolation barrier by a circuit including a modulator, and the circuit including a demodulator on the other side of the isolation barrier decodes the encoded signal to generate a PWM (Pulse Width Modulation) wave and output a feedback signal of the PWM wave. The feedback signal is transmitted to the control circuit 14 through the sub-transmission circuit 133. Therefore, the monitoring circuit 12 only needs to monitor the collector-emitter voltage V of the control switch 11 CE , the monitoring function can be completed without a complex current measurement circuit, which can simplify the design of the circuit where the control switch 11 is located and reduce the complexity and cost of the system.

[0054] In a specific implementation, the sub-collection circuit 132 includes a voltage-dividing structure 1311 and a collection structure 1312, the voltage-dividing structure 1311 includes at least one voltage-dividing resistor; the collection structure 1312 is coupled to the data processing chip 131, and the data processing chip 131 collects the electrical signal of the collection structure 1312 to obtain a characteristic signal.

[0055] In a specific implementation, in order to ensure the normal operation of the chip, it is necessary to rely on the voltage divider structure 1311 to divide the voltage input to the chip, so the sub-acquisition circuit 132 includes a voltage divider structure 1311 and an acquisition structure 1312, and the voltage divider structure 1311 includes at least one voltage divider resistor; the acquisition structure 1312 is coupled to the data processing chip 131, and the data processing chip 131 acquires the electrical signal of the acquisition structure 1312 to obtain a characteristic signal.

[0056] like Figure 3 As shown, the voltage dividing structure 1311 is R atten_1 to R atten_i , the collection structure 1312 is R LV_DC , the voltage dividing structure 1311 is connected in series with the collection structure 1312, and after voltage division by the voltage dividing resistor, the collection pin collects the voltage V of the collection structure 1312 AIN The size meets the input voltage range of AIN pin 0.6V~4.5V.

[0057] The resistors of the voltage divider structure 1311 and the acquisition structure 1312 are selected according to the maximum voltage of the input bus and the pin input voltage requirement to form a corresponding monitoring circuit 12. In a specific embodiment, reference can be made to V AIN The resistors of the voltage divider structure 1311 and the collection structure 1312 are selected according to the calculation formula:

[0058]

[0059] Among them, V AIN is the voltage collected by the AIN pin, R LV_DC For the corresponding Figure 3 R LV_DC Resistance, V CE is the input bus voltage value, I AIN The built-in constant current source is 200uA. for Figure 3 R atten_1 to R atten_i For example, if the maximum voltage of the DC bus related to the input power switch device is 800V, it can be calculated that five 510K resistors and one 8.2k resistor are configured to divide the 800V voltage.

[0060] like Figure 3As shown, the feedback signal is transmitted to the microcontroller μC of the control circuit 14 through the sub-transmission circuit 133. After the control circuit 14 receives the feedback signal of the PWM wave sent by the sub-transmission circuit 133, the feedback signal can reflect the acquired current or voltage of the control switch 11. The control circuit 14 determines that the feedback signal does not meet the preset working range. For example, when the value of the current or voltage is too large or too small, or when the value of the current or voltage increases or decreases sharply, the corresponding duty cycle of the PWM wave exceeds the preset range or the value increases or decreases sharply. The voltage of the control switch 11 collected by the sub-collection circuit 132 is determined, and the working state of the control switch 11 is determined according to the voltage value or the voltage change value.

[0061] In a specific embodiment, the PWM wave generated by the data processing chip 131 can be obtained according to the duty cycle calculation formula of the PWM wave:

[0062]

[0063] When the acquisition pin voltage changes from 4.5V to 0.6V, the duty cycle of the PWM wave changes linearly from 10% to 88%. In other embodiments, the coefficient and the constant term may be adjusted to obtain the value corresponding to the PWM wave.

[0064] In a specific embodiment, in order to improve the noise resistance of the acquisition structure 1312 input acquisition chip process, the state acquisition circuit 13 includes a filtering structure 134, the filtering structure 134 is coupled to the data processing chip 131, and the filtering structure 134 includes at least one capacitor; the filtering structure 134 is used to filter and reduce noise on the characteristic signal and / or feedback signal.

[0065] For example, a capacitor can be connected in parallel to the acquisition pin and / or in parallel to the signal pin. Figure 3 As shown, the capacitor C filt and resistor R filt connected in parallel between the COM pin and the AIN pin as a filter structure 134, and the capacitor C filt_2 and resistor R filt_2 Connected in parallel to the GND pin and the PWM pin, the COM pin and the GND pin are the common reference point pin and the ground point pin respectively.

[0066] See also Figure 4 , Figure 4 It is a structural schematic diagram of another implementation scheme of the monitoring circuit of the control switch of the present application.

[0067] The monitoring circuit 12 of the control switch 11 includes: the control switch 11 includes a first bridge arm 111 and a second bridge arm 112 coupled to each other in parallel, and the monitoring circuit 12 is coupled to the control switch 11 .

[0068] The control switch 11 may be a circuit structure composed of several power semiconductor devices, which is widely used in power electronic systems, such as frequency converters, inverters, and power drive systems. In a specific embodiment, the control switch 11 may be an IGBT (Insulated Gate Bipolar Transistor), which has an emitter, a base, and a collector. When a positive collector voltage V is applied to the emitter, CE , and a positive gate voltage V is applied to the emitter. GE When the IGBT is turned on, the collector and emitter are conducting, and the collector current I flows C , realizing the function of controlling switch 11.

[0069] When the control switch 11 is in a saturated conduction state during normal operation, its conduction voltage V CE If the circuit where the control switch 11 is located fails, the current changes sharply, V CE It will rise or fall rapidly. If it cannot be handled in time, the circuit may be damaged due to overload and other reasons.

[0070] In order to ensure the reliability of circuit operation, a first bridge arm 111 and a second bridge arm 112 are provided in the circuit of each phase of the three-phase electricity. When an abnormality occurs in the phase voltage, the monitoring circuit 12 is used to identify and locate the abnormality, and the correct current safety path is selected to ensure the normal operation of the circuit.

[0071] The monitoring circuit 12 includes: a state acquisition circuit 13, which acquires a characteristic signal of the control switch 11 and sends a feedback signal according to the characteristic signal; a control circuit 14, which is coupled to the state acquisition circuit 13, determines the working state of the control switch 11 according to the feedback signal, and when the working state of the control switch 11 is abnormal, locates the first bridge arm 111 or the second bridge arm 112 with an abnormal working state, and configures the other bridge arm with a normal working state to be turned on.

[0072] The monitoring circuit 12 can be multiplexed in the circuit structure, and the data processing chip 131 and the monitoring circuit 12 can be multiplexed in the circuit, or can be separately set in other embodiments. In a high-voltage, high-current circuit, the monitoring circuit 12 monitors the control switch 11, effectively monitors the working state of the control switch 11, so that the control switch 11 can be turned on or off at the appropriate time to protect the circuit.

[0073] In a specific implementation, a monitoring circuit 12 is provided in the circuit of each phase of the three-phase electricity to monitor the control switch 11 of each phase of the three-phase electricity. In other implementation circuits, only one monitoring circuit 12 may be provided to uniformly monitor the control switch 11 of the three-phase circuit. The characteristic signal of the control switch 11 may be a current or voltage signal flowing through the control switch 11. The current magnitude or current direction, or voltage magnitude, is detected. After the state acquisition circuit 13 processes the characteristic signal, such as modulation and demodulation, a feedback signal is generated. The feedback signal may also be a current or voltage signal generated by the state acquisition circuit 13. The feedback signal is then sent to the control circuit 14 to determine the working state of the control switch 11.

[0074] When the control switch 11 is in an abnormal working state, it is protectively shut down, the current passing through the control switch 11 is gradually reduced, and then the bridge arm in a normal working state is configured to be turned on.

[0075] In a specific embodiment, the state acquisition circuit 13 is coupled to the first bridge arm 111, or to the second bridge arm 112, or to the first bridge arm 111 and to the second bridge arm 112 respectively; the state acquisition circuit 13 collects the characteristic signal of the corresponding bridge arm and sends a feedback signal according to the characteristic signal.

[0076] In a specific embodiment, when the state acquisition circuit 13 is coupled to the first bridge arm 111, the state acquisition circuit 13 can acquire the feedback signal of the first bridge arm 111, that is, the monitoring circuit 12 can monitor the working state of the first bridge arm 111, and then indirectly obtain the working state of the second bridge arm 112. In other embodiments, when the state acquisition circuit 13 is coupled to the second bridge arm 112, the state acquisition circuit 13 can acquire the feedback signal of the second bridge arm 112, that is, the monitoring circuit 12 can monitor the working state of the second bridge arm 112, and then indirectly obtain the working state of the first bridge arm 111. When the state acquisition circuit 13 is coupled to the first bridge arm 111 and to the second bridge arm 112 respectively, the state acquisition circuit 13 can respectively acquire the feedback signals of the first bridge arm 111 and the second bridge arm 112, that is, the two monitoring circuits 12 can respectively monitor the working states of the first bridge arm 111 and the second bridge arm 112.

[0077] In a specific implementation, the state acquisition circuit 13 includes a data processing chip 131 , a sub-acquisition circuit 132 , and a sub-transmission circuit 133 .

[0078] The sub-acquisition circuit 132 is coupled to the acquisition pin of the data processing chip 131; the data processing chip 131 generates a feedback signal according to the characteristic signal collected by the sub-acquisition circuit 132; the sub-transmission circuit 133 is coupled to the signal pin of the data processing chip 131; the sub-transmission circuit 133 sends a feedback signal.

[0079] In a specific embodiment, see Figure 5 , Figure 5 It is a structural diagram of a specific embodiment of another implementation scheme of the monitoring circuit for controlling the switch of the present application; the state acquisition circuit 13 is coupled to the second bridge arm 112, and the state of the state acquisition circuit 13 can collect the feedback signal of the second bridge arm 112, that is, the monitoring circuit 12 can monitor the working state of the second bridge arm 112, and then indirectly obtain the working state of the first bridge arm 111.

[0080] like Figure 5 As shown, the data processing chip 131 is a 16-pin isolation driver chip, with pins 1-8 connected to the high voltage side HV, and pins 9-16 connected to the low voltage side LV. An isolation barrier is provided inside to provide electrical isolation to prevent direct electrical connection between the high voltage side HV and the low voltage side LV. The acquisition pin uses a 1-pin AIN pin, and the signal pin is a 16-pin PWM pin structure design.

[0081] In a specific implementation, the acquisition pins respectively acquire the voltage of the negative busbar output of each phase of the three-phase power, collect the feedback signal through the acquisition pins, and then send the feedback signal through the signal pins. Specifically, the characteristic signal V detected by the AIN pin AIN Can reflect the collector-emitter voltage V of the control switch 11 CE The circuit including the modulator converts the PWM input signal into a signal suitable for transmission through the isolation barrier, and the circuit including the demodulator on the other side of the isolation barrier decodes the encoded signal to generate a PWM wave and output a feedback signal of the PWM wave. The feedback signal is transmitted to the control circuit 14 through the sub-transmission circuit 133.

[0082] In a specific embodiment, Figure 5 The schematic diagram of the partial structure of the detection circuit's acquisition pin AIN pin and the signal PWM pin related circuit, wherein the sub-acquisition circuit 132 includes a voltage-dividing structure 1311 and an acquisition structure 1312, the voltage-dividing structure 1311 includes at least one voltage-dividing resistor; the acquisition structure 1312 is coupled to the data processing chip 131, and the data processing chip 131 acquires the electrical signal of the acquisition structure 1312 to obtain a characteristic signal. Figure 5 As shown, the state acquisition circuit 13 also includes circuits TM-C_U_LS, TM-G_U_LS and TM-E_U_LS respectively connected to the collector C2, gate G2 and emitter D2 of the second bridge arm 112, and the circuit TM-C_U_LS is connected through the voltage divider structure 1311 to realize the collector-emitter voltage V of the control switch 11. CE Therefore, the monitoring circuit 12 only needs to monitor the collector-emitter voltage V of the control switch 11.CE , the monitoring function can be completed without a complex current measurement circuit, which can simplify the design of the circuit where the control switch 11 is located and reduce the complexity and cost of the system.

[0083] like Figure 5 As shown, the data processing chip 131 includes a VDD pin (not labeled in the figure) and a VCC pin (not labeled in the figure) of power supply pins, a VDD pin circuit (not labeled in the figure) connected to the VDD pin, a VCC pin connected to the VCC pin, a circuit TM-P15V_U_LS and a circuit TM_P5VDP-LS connected to a power supply, and provides power to different parts inside the data processing chip 131 by connecting to the VDD pin circuit and the VCC pin circuit;

[0084] In a specific implementation, in order to ensure the normal operation of the data processing chip 131, it is necessary to rely on the voltage divider structure 1311 to divide the voltage input to the chip, so the sub-acquisition circuit 132 includes a voltage divider structure 1311 and an acquisition structure 1312, and the voltage divider structure 1311 includes at least one voltage divider resistor; the acquisition structure 1312 is coupled to the data processing chip 131, and the data processing chip 131 acquires the electrical signal of the acquisition structure 1312 to obtain a characteristic signal.

[0085] The voltage dividing structure 1311 is R atten_1 to R atten_i correspond Figure 5 R225, R246, R247, R248, R249 shown, the collection structure 1312 is R LV_DC Corresponding to R250, the voltage divider structure 1311 is connected in series with the acquisition structure 1312. After voltage division by the voltage divider resistor, the acquisition pin acquires the voltage V of the acquisition structure 1312. AIN The size meets the input voltage range of AIN pin 0.6V~4.5V.

[0086] The resistors of the voltage divider structure 1311 and the acquisition structure 1312 are selected according to the maximum voltage of the input bus and the pin input voltage requirement to form a corresponding monitoring circuit 12. In a specific embodiment, reference can be made to V AIN The resistors of the voltage divider structure 1311 and the collection structure 1312 are selected according to the calculation formula:

[0087]

[0088] Among them, V AIN is the voltage collected by the AIN pin, R LV_DC For the corresponding Figure 5 The resistance value of R250, V CE is the input bus voltage value, I AINThe built-in constant current source is 200uA. for Figure 5 The sum of the resistances of R225, R246, R247, R248, and R249. For example, the maximum voltage of the DC bus associated with the input power switch device is 800V. After calculation, it can be obtained that five 510K resistors and one 8.2k resistor are configured to divide the 800V voltage.

[0089] like Figure 5 As shown, the feedback signal is transmitted to the MCU_State of the control circuit 14 through the sub-transmission circuit 133. After the control circuit 14 receives the feedback signal of the PWM wave sent by the sub-transmission circuit 133, the feedback signal can reflect the acquired current or voltage of the control switch 11. The control circuit 14 determines that the feedback signal does not meet the preset working range. For example, when the value of the current or voltage is too large or too small, or when the value of the current or voltage increases or decreases sharply, the duty cycle of the corresponding PWM wave exceeds the preset range or the value increases or decreases sharply. The voltage of the control switch 11 collected by the sub-collection circuit 132 is determined, and the working state of the control switch 11 is determined according to the voltage value or the voltage change value.

[0090] The duty cycle of the PWM wave corresponds to the state acquisition circuit 13 acquiring the three-phase output voltage of the circuit where the control switch 11 is located, that is, the corresponding V CE The control circuit 14 will also directly collect the highest input bus voltage of the controller. When the output voltage is the same as the input voltage, it can be determined that there is no abnormality in the corresponding coupled bridge arm, and it can be inferred that there is an abnormality in the other bridge arm.

[0091] In a specific embodiment, the PWM wave generated by the data processing chip 131 can be obtained according to the duty cycle calculation formula of the PWM wave:

[0092]

[0093] When the acquisition pin voltage changes from 4.5V to 0.6V, the duty cycle of the PWM wave changes linearly from 10% to 88%. In other embodiments, the coefficient and the constant term may be adjusted to obtain the value corresponding to the PWM wave.

[0094] In a specific embodiment, in order to improve the noise resistance of the acquisition structure 1312 input acquisition chip process, the state acquisition circuit 13 includes a filtering structure 134, the filtering structure 134 is coupled to the data processing chip 131, and the filtering structure 134 includes at least one capacitor; the filtering structure 134 is used to filter and reduce noise on the characteristic signal and / or feedback signal.

[0095] For example, a capacitor can be connected in parallel to the acquisition pin and / or in parallel to the signal pin. Figure 5As shown, the data processing chip 131 also includes a COM pin (not marked in the figure) of a common reference point pin and a GND pin (not marked in the figure) of a ground point pin, the COM pin is connected to a COM pin circuit (not marked in the figure) to realize connection with the circuit TM-E_U_LS, the capacitor C239 is connected in parallel between the COM pin and the AIN pin as a filtering structure 134, and the capacitor C218 is connected in parallel to the GND pin and the PWM pin.

[0096] In a specific embodiment, a data processing chip 131 is coupled to the first bridge arm 111, and the data processing chip 131 coupled to the first bridge arm 111 and the second bridge arm 112 is provided with a SAT pin (not marked in the figure) as a protection pin. The method of coupling the SAT pin of the data processing chip 131 on the first bridge arm 111 can refer to Figure 5 The second bridge arm 112 is coupled to the SAT pin of the data processing chip 131. The SAT pin is connected to the SAT pin circuit (not shown) to obtain the current or voltage of the control switch 11. When the SAT pin detects V CE When the voltage drops below a preset threshold, a protection signal is sent to configure the first bridge arm 111 and the second bridge arm 112 to gradually reduce the input current for slow shutdown protection.

[0097] The data processing chip 131 in this embodiment is a UCC21750-Q1 chip. In other embodiments, the signal structure of the data processing chip 131 is not unique, and the set pins are not unique. As long as the data processing chip 131 can implement the logical structure or detection function in the above-mentioned embodiment, it will be sufficient. The VDD pin circuit, VCC pin circuit, SAT pin circuit, and COM pin circuit connected to the pins of the data processing chip 131 mentioned in this embodiment may at least partially belong to the structure of the monitoring circuit, or be connected to the monitoring circuit, and be used for the detection circuit to monitor the working state of the control switch, thereby improving the reliability and stability of the control switch.

[0098] The monitoring circuit provided in the above embodiment can monitor the working state of the control switch in real time, so that the circuit where the control switch is located can select a suitable safe path between the first bridge arm and the second bridge arm, and can better withstand the working environment of high current and voltage. The reliability and stability of the control switch are improved, and fault finding and protection circuits are facilitated. The monitoring circuit structure is simple, and switches in abnormal working states can be more accurately judged, which is conducive to reducing production costs and maintenance costs.

[0099] The present application also provides a monitoring method of a monitoring circuit based on a control switch.

[0100] See also Figure 6 , Figure 6The present invention is a flow chart of a monitoring method for a monitoring circuit based on a control switch in an embodiment of the present invention. The monitoring method of this embodiment is used to monitor the working state of the control switch and control the control switch.

[0101] The control switch includes a first bridge arm and a second bridge arm coupled in parallel to each other, the monitoring circuit includes a state acquisition circuit and a control circuit coupled to each other, and the monitoring circuit is coupled to the control switch.

[0102] In a specific implementation, a monitoring circuit is set in the circuit of each phase of the three-phase electricity to monitor the control switch of each phase of the three-phase electricity. In other implementation circuits, only one monitoring circuit may be set to uniformly monitor the control switches of the three-phase circuit.

[0103] Among them, monitoring methods include:

[0104] S101: The state acquisition circuit acquires a characteristic signal of a control switch and sends a feedback signal according to the characteristic signal.

[0105] The characteristic signal of the control switch can be a current or voltage signal flowing through the control switch. The current size or current direction, or voltage size is detected. After the state acquisition circuit processes the characteristic signal, such as modulation and demodulation, it generates a feedback signal. The feedback signal can also be a current or voltage signal generated by the state acquisition circuit, and then the feedback signal is sent to the control circuit.

[0106] S102: The control circuit determines the working state of the control switch according to the feedback signal.

[0107] The feedback signal can reflect the obtained current or voltage of the control switch. When the control circuit determines that the feedback signal does not meet the preset working range, for example, when the current or voltage value is too large or too small, or when the current or voltage value increases or decreases sharply, it can be determined that the working state of the control switch is abnormal.

[0108] S103: In response to the control switch operating state being abnormal, locating the first bridge arm or the second bridge arm whose operating state is abnormal, and configuring the other bridge arm whose operating state is normal to be turned on.

[0109] When the control switch is in an abnormal working state, it is protected and shut down, the current passing through the control switch is gradually reduced, and then the bridge arm with normal working state is configured to be turned on. In the high-voltage and high-current circuit, the monitoring circuit monitors the control switch and effectively monitors the working state of the control switch, so that the control switch can be turned on or off at the right time to protect the circuit.

[0110] See also Figure 7 , Figure 7This is a flow chart of another embodiment of a monitoring method based on a monitoring circuit of a control switch of the present application. The monitoring method of this embodiment is used to monitor the working state of the control switch and control the control switch.

[0111] The control switch includes a first bridge arm and a second bridge arm coupled in parallel to each other, the monitoring circuit includes a state acquisition circuit and a control circuit coupled to each other, and the monitoring circuit is coupled to the control switch. The structural relationship between the control switch and the monitoring circuit can be referred to Figure 2 and Figure 3 The structural relationship between the structural schematic diagram of another implementation manner of the monitoring circuit for controlling the switch of the present application and the structural schematic diagram of a specific example of another implementation manner.

[0112] In a specific implementation, a monitoring circuit is set in the circuit of each phase of the three-phase electricity to monitor the control switch of each phase of the three-phase electricity. In other implementation circuits, only one monitoring circuit may be set to uniformly monitor the control switches of the three-phase circuit.

[0113] Among them, monitoring methods include:

[0114] The state acquisition circuit acquires the characteristic signal of the control switch and sends a feedback signal according to the characteristic signal. The characteristic signal of the control switch can be a current or voltage signal flowing through the control switch, and the current magnitude or current direction, or voltage magnitude, is detected. After the state acquisition circuit processes the characteristic signal, such as modulation and demodulation, it generates a feedback signal. The feedback signal can also be a current or voltage signal generated by the state acquisition circuit, and then the feedback signal is sent to the control circuit.

[0115] In a specific implementation, the state acquisition circuit includes a data processing chip, a sub-acquisition circuit and a sub-transmission circuit. S201: The sub-acquisition circuit acquires a characteristic signal of a control switch; the data processing chip generates a feedback signal according to the characteristic signal; and the feedback signal is sent through the sub-transmission circuit.

[0116] In a specific implementation, please refer to Figure 2 The structural diagram of another embodiment of the monitoring circuit of the control switch of the present application, the acquisition pin of the data processing chip, namely the AIN pin, respectively collects the voltage of the negative bus output of each phase of the three-phase power, collects the feedback signal through the acquisition pin, and then sends the feedback signal through the signal pin, namely the PWM pin. Specifically, the characteristic signal V detected by the AIN pin AIN Can reflect the collector-emitter voltage V of the control switch CE, the PWM input signal is converted into a signal suitable for transmission through the isolation barrier by a circuit including a modulator, and the circuit including a demodulator on the other side of the isolation barrier decodes the encoded signal to generate a PWM (Pulse Width Modulation) wave and output a feedback signal of the PWM wave. The feedback signal is transmitted to the control circuit through the sub-transmission circuit.

[0117] The PWM wave generated by the data processing chip can be obtained according to the PWM wave duty cycle calculation formula:

[0118]

[0119] When the acquisition pin voltage changes from 4.5V to 0.6V, the duty cycle of the PWM wave changes linearly from 10% to 88%. In other embodiments, the coefficient and the constant term may be adjusted to obtain the value corresponding to the PWM wave.

[0120] S202: The control circuit determines the working state of the control switch according to the feedback signal.

[0121] The feedback signal can reflect the obtained current or voltage of the control switch. The control circuit determines that the feedback signal does not meet the preset working range. For example, when the current or voltage value is too large or too small, or the current or voltage value increases or decreases sharply, the corresponding PWM wave duty cycle exceeds the preset range or the value increases or decreases sharply, then it can be determined that the working state of the control switch is abnormal.

[0122] S203: In response to the control switch operating state being abnormal, locating the first bridge arm or the second bridge arm whose operating state is abnormal, and configuring the other bridge arm whose operating state is normal to be turned on.

[0123] When the control switch is in an abnormal working state, it is protected and shut down, the current passing through the control switch is gradually reduced, and then the bridge arm with normal working state is configured to be turned on. In the high-voltage and high-current circuit, the monitoring circuit monitors the control switch and effectively monitors the working state of the control switch, so that the control switch can be turned on or off at the right time to protect the circuit.

[0124] See also Figure 8 , Figure 8 This is a flow chart of another embodiment of a monitoring method based on a monitoring circuit of a control switch of the present application. The monitoring method of this embodiment is used to monitor the working state of the control switch and control the control switch.

[0125] The control switch includes a first bridge arm and a second bridge arm coupled in parallel to each other, the monitoring circuit includes a state acquisition circuit and a control circuit coupled to each other, and the monitoring circuit is coupled to the control switch. The structural relationship between the control switch and the monitoring circuit can be referred to Figure 4 and Figure 5 The structural relationship between the structural schematic diagram of another implementation manner of the monitoring circuit for controlling the switch of the present application and the structural schematic diagram of a specific example of another implementation manner.

[0126] In a specific implementation, a monitoring circuit is set in the circuit of each phase of the three-phase electricity to monitor the control switch of each phase of the three-phase electricity. In other implementation circuits, only one monitoring circuit may be set to uniformly monitor the control switches of the three-phase circuit.

[0127] Among them, monitoring methods include:

[0128] The state acquisition circuit acquires the characteristic signal of the control switch and sends a feedback signal according to the characteristic signal. The characteristic signal of the control switch can be a current or voltage signal flowing through the control switch, and the current magnitude or current direction, or voltage magnitude, is detected. After the state acquisition circuit processes the characteristic signal, such as modulation and demodulation, it generates a feedback signal. The feedback signal can also be a current or voltage signal generated by the state acquisition circuit, and then the feedback signal is sent to the control circuit.

[0129] In a specific implementation, the state acquisition circuit includes a data processing chip, a sub-acquisition circuit and a sub-transmission circuit. S301: The sub-acquisition circuit acquires a characteristic signal of a control switch; the data processing chip generates a feedback signal according to the characteristic signal; and the feedback signal is sent through the sub-transmission circuit.

[0130] In a specific implementation, please refer to Figure 5 The structural diagram of another embodiment of the monitoring circuit of the control switch of the present application, the acquisition pin of the data processing chip, namely the AIN pin, respectively collects the voltage of the negative bus output of each phase of the three-phase power, collects the feedback signal through the acquisition pin, and then sends the feedback signal through the signal pin, namely the PWM pin. Specifically, the characteristic signal V detected by the AIN pin AIN Can reflect the collector-emitter voltage V of the control switch CE , the PWM input signal is converted into a signal suitable for transmission through the isolation barrier by a circuit including a modulator, and the circuit including a demodulator on the other side of the isolation barrier decodes the encoded signal to generate a PWM (Pulse Width Modulation) wave and output a feedback signal of the PWM wave. The feedback signal is transmitted to the control circuit through the sub-transmission circuit.

[0131] The control circuit determines the working state of the control switch according to the feedback signal. In a specific implementation, S302: the control circuit collects the electrical signal of the control switch input voltage, and in response to the feedback signal and the electrical signal not meeting the preset working range, determines that the working state of the control switch is an abnormal state.

[0132] The PWM wave generated by the data processing chip can be obtained according to the PWM wave duty cycle calculation formula:

[0133]

[0134] When the acquisition pin voltage changes from 4.5V to 0.6V, the duty cycle of the PWM wave changes linearly from 10% to 88%. In other embodiments, the coefficient and the constant term may be adjusted to obtain the value corresponding to the PWM wave.

[0135] The feedback signal can reflect the obtained current or voltage of the control switch. The control circuit determines that the feedback signal does not meet the preset working range. For example, when the current or voltage value is too large or too small, or the current or voltage value increases or decreases sharply, the corresponding PWM wave duty cycle exceeds the preset range or the value increases or decreases sharply, then it can be determined that the working state of the control switch is abnormal.

[0136] The duty cycle of the PWM wave corresponds to the state acquisition circuit that collects the three-phase output voltage of the circuit where the control switch is located, that is, the V corresponding to the control switch. CE The control circuit will also directly collect the highest input bus voltage of the controller. When the output voltage is the same as the input voltage, it can be determined that there is no abnormality in the corresponding coupled bridge arm, and it can be inferred that there is an abnormality in the other bridge arm.

[0137] In a specific embodiment, the state acquisition circuit is coupled to the first bridge arm, or to the second bridge arm, or to the first bridge arm and to the second bridge arm respectively; the state acquisition circuit acquires the characteristic signal of the control switch, and the step of sending a feedback signal according to the characteristic signal includes: the state acquisition circuit 13 acquires the characteristic signal of the corresponding bridge arm, and sends a feedback signal according to the characteristic signal.

[0138] In a specific embodiment, when the state acquisition circuit is coupled to the first bridge arm, the state acquisition circuit can acquire the feedback signal of the first bridge arm, that is, the monitoring circuit can monitor the working state of the first bridge arm, and then indirectly obtain the working state of the second bridge arm. In other embodiments, when the state acquisition circuit is coupled to the second bridge arm, the state acquisition circuit state can acquire the feedback signal of the second bridge arm, that is, the monitoring circuit can monitor the working state of the second bridge arm, and then indirectly obtain the working state of the first bridge arm. When the state acquisition circuit is coupled to the first bridge arm and to the second bridge arm respectively, the state acquisition circuit state can respectively acquire the feedback signals of the first bridge arm and the second bridge arm, that is, the two monitoring circuits can respectively monitor the working states of the first bridge arm and the second bridge arm.

[0139] In a specific implementation, S303: the data processing chip detects that the electrical signal of the control switch input voltage is in an abnormal state, and the data processing chip configures the control switch to gradually reduce the input current for slow shutdown protection; the control circuit locates the first bridge arm or the second bridge arm whose working state is abnormal, and configures the other bridge arm whose working state is normal to be turned on.

[0140] In a specific embodiment, please refer to Figure 5 A structural diagram of another embodiment of the monitoring circuit of the control switch of the present application, wherein the monitoring circuit is coupled to the second bridge arm, a data processing chip is coupled to the first bridge arm, and the data processing chips coupled to the first bridge arm and the second bridge arm are both provided with a protection pin SAT pin to obtain the current or voltage of the control switch. When the SAT pin detects V CE When the voltage drops below a preset threshold, a protection signal is sent to configure the first bridge arm and the second bridge arm to gradually reduce the input current for slow shutdown protection.

[0141] When the control switch is in an abnormal working state, the control circuit configures the control switch to protect it by shutting it down, gradually reducing the current passing through the control switch, and then configuring the bridge arm in normal working state to turn on, so that in a high-voltage, high-current circuit, the monitoring circuit monitors the control switch and effectively monitors the working state of the control switch, so that the control switch can be turned on or off at the appropriate time to protect the circuit.

[0142] The monitoring method provided in the above embodiment can monitor the working state of the control switch in real time, so that the circuit where the control switch is located can select a suitable safe path between the first bridge arm and the second bridge arm, and can better withstand the working environment of high current and voltage. The reliability and stability of the control switch are improved, and fault finding and protection circuits are facilitated. The monitoring circuit structure is simple, and switches in abnormal working states can be more accurately judged, which is conducive to reducing production costs and maintenance costs.

[0143] This application also provides a power system 21, see Fig. 9 , Fig. 9 It is a structural schematic diagram of an implementation scheme of a power system 21 of the present application.

[0144] The power system 21 includes a monitoring circuit 12 and a control switch 11 . The control switch 11 includes a first bridge arm 111 and a second bridge arm 112 coupled in parallel to each other. The monitoring circuit 12 is any one of the above monitoring circuits 12 .

[0145] The control switch 11 may be a circuit structure composed of several power semiconductor devices, which is widely used in power electronic systems, such as frequency converters, inverters, and power drive systems. In a specific embodiment, the control switch 11 may be an IGBT (Insulated Gate Bipolar Transistor), which has an emitter, a base, and a collector. When a positive collector voltage V is applied to the emitter, CE , and a positive gate voltage V is applied to the emitter. GE When the IGBT is turned on, the collector and emitter are conducting, and the collector current I flows C , realizing the function of controlling switch 11.

[0146] In order to ensure the reliability of circuit operation, a first bridge arm 111 and a second bridge arm 112 are provided in the circuit of each phase of the three-phase electricity. When an abnormality occurs in the phase voltage, the monitoring circuit 12 is used to identify and locate the abnormality, and the correct current safety path is selected to ensure the normal operation of the circuit.

[0147] When the control switch 11 is in a saturated conduction state during normal operation, its conduction voltage V CE If the circuit where the control switch 11 is located fails, the current changes sharply, V CE It will rise or fall rapidly. If it cannot be handled in time, the circuit may be damaged due to overload and other reasons.

[0148] The monitoring circuit 12 can be multiplexed in the circuit structure, and the data processing chip 131 and the monitoring circuit 12 can be multiplexed in the circuit, or it can be set separately. In the high-voltage and high-current circuit, the monitoring circuit 12 monitors the control switch 11, effectively monitors the working state of the control switch 11, so that the control switch 11 can be turned on or off at the appropriate time, thereby protecting the circuit.

[0149] In a specific embodiment, when the state acquisition circuit 13 is coupled to the first bridge arm 111, the state acquisition circuit 13 can acquire the feedback signal of the first bridge arm 111, that is, the monitoring circuit 12 can monitor the working state of the first bridge arm 111, and then indirectly obtain the working state of the second bridge arm 112. In other embodiments, when the state acquisition circuit 13 is coupled to the second bridge arm 112, the state acquisition circuit 13 can acquire the feedback signal of the second bridge arm, that is, the monitoring circuit 12 can monitor the working state of the second bridge arm 112, and then indirectly obtain the working state of the first bridge arm 111. When the state acquisition circuit 13 is coupled to the first bridge arm 111 and to the second bridge arm 112 respectively, the state acquisition circuit 13 can respectively acquire the feedback signals of the first bridge arm 111 and the second bridge arm 112, that is, the two monitoring circuits 12 can respectively monitor the working states of the first bridge arm 111 and the second bridge arm 112.

[0150] In a specific embodiment, the duty cycle of the PWM wave corresponds to the state acquisition circuit 13 acquiring the three-phase output voltage of the circuit where the control switch 11 is located, that is, the corresponding V of the control switch 11. CE The control circuit 14 will also directly collect the highest input bus voltage of the controller. When the output voltage is the same as the input voltage, it can be determined that the corresponding coupled bridge arm is not abnormal, and it can be inferred that the other bridge arm is abnormal. In other embodiments, the feedback signal can reflect the acquired current or voltage of the control switch. The control circuit determines that the feedback signal does not meet the preset working range. For example, when the value of the current or voltage is too large or too small, or the value of the current or voltage increases or decreases sharply, the duty cycle of the corresponding PWM wave exceeds the preset range or the value increases or decreases sharply, it can be determined that the working state of the control switch is abnormal.

[0151] It reflects whether the power system 21 and the control switch 11 are in normal working condition, or whether there are potential faults, and understands the working status of the power system 21 in real time, improves the reliability and stability of the power system 21 and the control switch 11, and can avoid adding additional sensors and other monitoring elements while reusing the original data processing chip 131 and the monitoring circuit 12, thereby effectively reducing the cost of the power system 21.

[0152] Different from the prior art, the present application provides a monitoring circuit, monitoring method and power system for a control switch, which can monitor the working state of the control switch in real time, so that the circuit where the control switch is located can select a suitable safe path between the first bridge arm and the second bridge arm, and can better withstand the working environment of high current and voltage. The reliability and stability of the control switch are improved, which is convenient for fault finding and circuit protection. The monitoring circuit structure is simple, and the switch in abnormal working state can be judged more accurately, which is conducive to reducing production and maintenance costs.

[0153] In the several embodiments provided in the present application, it should be understood that the disclosed systems and devices can be implemented in other ways. For the technical solutions in the embodiments of the present application, it is obvious that the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application. For example, the device implementation described above is only schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0154] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back...), such directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0155] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "coupled", "connected", "connected", "set", and "installed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0156] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0157] In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0158] The above description is only an implementation method of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A monitoring circuit for controlling a switch, characterized in that: The control switch includes a first bridge arm and a second bridge arm coupled in parallel with each other, and each phase circuit is provided with the first bridge arm and the second bridge arm, and the monitoring circuit is coupled to the control switch; the monitoring circuit includes: A state acquisition circuit, the state acquisition circuit is coupled to the first bridge arm, or coupled to the second bridge arm, or coupled to the first bridge arm and the second bridge arm respectively; the state acquisition circuit acquires a characteristic signal corresponding to the bridge arm, and sends a feedback signal according to the characteristic signal; a control circuit, the control circuit being coupled to the state acquisition circuit, determining the working state of the control switch according to the feedback signal, and when the working state of the control switch is abnormal, locating the first bridge arm or the second bridge arm whose working state is abnormal, and configuring the other bridge arm whose working state is normal to be turned on; The state acquisition circuit includes a data processing chip, a sub-acquisition circuit and a sub-transmission circuit. The acquisition pins of the sub-acquisition circuit and the data processing chip are coupled to each other. The data processing chip generates the feedback signal according to the characteristic signal collected by the sub-acquisition circuit. The sub-transmission circuit is coupled to the signal pins of the data processing chip. The sub-transmission circuit sends the feedback signal.

2. The monitoring circuit according to claim 1, characterized in that: The sub-collection circuit includes a voltage-dividing structure and a collection structure, and the voltage-dividing structure includes at least one voltage-dividing resistor; The acquisition structure is coupled to the data processing chip, and the data processing chip acquires the electrical signal of the acquisition structure to obtain the characteristic signal.

3. The monitoring circuit according to claim 1, characterized in that: The state acquisition circuit includes a filter structure, which is coupled to the data processing chip and includes at least one capacitor; the filter structure is used to filter and reduce noise on the characteristic signal and / or the feedback signal.

4. A monitoring method for a monitoring circuit based on a control switch, characterized in that: The control switch includes a first bridge arm and a second bridge arm coupled in parallel to each other, the monitoring circuit includes a state acquisition circuit and a control circuit coupled to each other, the monitoring circuit is coupled to the control switch, the state acquisition circuit includes a data processing chip, a sub-acquisition circuit and a sub-transmission circuit, the state acquisition circuit is coupled to the first bridge arm, or to the second bridge arm, or to the first bridge arm and to the second bridge arm respectively; the monitoring method includes: The state acquisition circuit acquires the characteristic signal corresponding to the bridge arm, and sends the feedback signal according to the characteristic signal, specifically comprising: the sub-acquisition circuit acquires the characteristic signal of the control switch; the data processing chip generates the feedback signal according to the characteristic signal; and the feedback signal is sent through the sub-transmission circuit; The control circuit determines the working state of the control switch according to the feedback signal; In response to the control switch operating state being abnormal, the first bridge arm or the second bridge arm whose operating state is abnormal is located, and the other bridge arm whose operating state is normal is configured to be turned on.

5. The monitoring method according to claim 4, characterized in that: The step of the control circuit determining the working state of the control switch according to the feedback signal comprises: The control circuit collects an electrical signal of the control switch input voltage, and determines that the working state of the control switch is an abnormal state in response to the feedback signal and the electrical signal not satisfying a preset working range.

6. The monitoring method according to claim 4 or 5, characterized in that: In response to the control switch operating state being abnormal, the step of locating the first bridge arm or the second bridge arm whose operating state is abnormal, and configuring the other bridge arm whose operating state is normal to be turned on comprises: In response to the operating state of the control switch being abnormal, configuring the control switch to gradually reduce the input current for slow shutdown protection; It is determined that the first bridge arm or the second bridge arm has an abnormal working state, and the other bridge arm with a normal working state is configured to be turned on.

7. A power system, characterized in that: The power system includes a monitoring circuit and a control switch, the control switch includes a first bridge arm and a second bridge arm coupled in parallel with each other, and the monitoring circuit is the monitoring circuit according to any one of claims 1 to 3.

Images