Control circuit for a discharge circuit and redundant active discharge circuit

Abstract

The utility model relates to new energy automobile motor discharging technical field discloses a control circuit and redundancy initiative discharging circuit of discharging circuit, and the control circuit of discharging circuit includes: discharging voltage detection circuit, discharging current detection circuit, logic control circuit, drive circuit, wherein, the input end of discharging voltage detection circuit connects discharging voltage signal, the input end of discharging current detection circuit connects discharging current signal, the first input end of logic control circuit inputs initiative discharging signal, and the second input end of logic control circuit is connected with the output of discharging voltage detection circuit and the output of discharging current detection circuit, and the output of logic control circuit is connected with the input of drive circuit. The utility model can adjust initiative discharging strategy of discharging circuit according to the redundancy detection of discharging current, discharging voltage, improves the security and reliability of discharging.

Description

Technical Field

[0001] This utility model relates to the field of electric motor discharge technology for new energy vehicles, specifically to a control circuit and a redundant active discharge circuit for a discharge circuit. Background Technology

[0002] As a core component of new energy electric vehicles, the motor controller's safety performance directly affects the reliability of the vehicle's high-voltage system and the safety of passengers. In the event of a serious anomaly detected by the electric vehicle system or a collision, to ensure the safety of the high-voltage circuit, the vehicle's positive and negative main relays will immediately disconnect, severing the electrical connection between the power battery and the high-voltage components. Simultaneously, to quickly dissipate the back electromotive force that may be generated by the motor's rotation and to prevent overvoltage damage to power devices, the motor controller's power module typically needs to prioritize an active short circuit (ASC) strategy, short-circuiting the motor windings.

[0003] However, under these specific operating conditions, since the main relay has been disconnected, the supporting capacitors connected to the high-voltage bus, especially the film capacitors inside the motor controller, will still retain a voltage of several hundred volts. Conventional active discharge schemes typically rely on the motor windings and inverter bridge arms to form a circuit, reducing the capacitor voltage through energy dissipation; however, in ASC mode, this path is occupied or blocked and cannot be used for discharge, thus conventional active discharge methods fail in this situation. If energy release is achieved solely by relying on the inherent passive discharge resistance of the high-voltage system, the discharge time will be long, potentially reaching several minutes, which cannot meet the safety regulations requiring rapid power disconnection of high-voltage components in emergency situations.

[0004] Furthermore, existing active discharge schemes generally lack effective detection and status feedback mechanisms for the discharge process, making it impossible to confirm in real time whether the discharge has been successfully initiated, whether it has proceeded as expected, and whether it has been completed within the specified time. This lack of detection makes it difficult for the system to achieve redundant diagnosis and closed-loop management of the discharge function, thus failing to meet the high reliability requirements of high-voltage safety circuits. Utility Model Content

[0005] This invention provides a control circuit and a redundant active discharge circuit for a discharge circuit, in order to solve the problem that discharge circuits in the prior art cannot be redundantly controlled.

[0006] In a first aspect, this utility model provides a control circuit for a discharge circuit, comprising: a discharge voltage detection circuit, a discharge current detection circuit, a logic control circuit, and a drive circuit. The discharge voltage detection circuit receives a discharge voltage signal at its input terminal and is used to determine whether the slope of the discharge voltage is within a preset voltage slope range, and outputs a voltage detection signal. The discharge current detection circuit receives a discharge current signal at its input terminal and is used to determine whether the slope of the discharge current is within a preset current slope range, and outputs a current detection signal. The logic control circuit receives an active discharge signal at its first input terminal, and its second input terminal is connected to the output terminals of both the discharge voltage detection circuit and the discharge current detection circuit. The output terminal of the logic control circuit is connected to the input terminal of the drive circuit, and the logic control circuit outputs a drive signal based on a built-in truth table. The drive circuit controls the operating state of the discharge circuit based on the drive signal from the logic control circuit.

[0007] The control circuit of the discharge circuit provided by this utility model has dual redundant detection loops: a discharge voltage detection circuit and a discharge current detection circuit. These two detection circuits are mutually redundant. When both circuits detect an abnormality (such as no voltage change after a discharge command or an abnormal current surge), the logic control circuit can promptly cut off the output and shut down the discharge process, ensuring absolute reliability of state identification and avoiding misjudgments or missed judgments that may result from single-point monitoring failure. The control circuit of the discharge circuit provided by this utility model not only efficiently and quickly completes the discharge task under normal conditions, but also redundantly monitors the discharge status and controls the opening or closing of the discharge circuit, ensuring the safety of the discharge process.

[0008] In one optional embodiment, the discharge voltage detection circuit includes a voltage divider circuit and a voltage slope detection circuit. The input terminal of the voltage divider circuit is connected to the discharge voltage signal, and the output terminal of the voltage divider circuit is connected to the input terminal of the voltage slope detection circuit. The voltage divider circuit is used to divide the discharge voltage signal. The output terminal of the voltage slope detection circuit is connected to the second input terminal of the logic control circuit. The voltage slope detection circuit is used to determine whether the slope of the discharge voltage is within a preset voltage slope range and output a voltage detection signal.

[0009] In one alternative implementation, the voltage divider circuit includes a plurality of voltage divider resistors connected in series and / or in parallel.

[0010] In one optional embodiment, the discharge current detection circuit includes a current acquisition circuit and a current slope detection circuit. The input terminal of the current acquisition circuit is connected to the discharge current signal, and the output terminal of the current acquisition circuit is connected to the input terminal of the current slope detection circuit. The current acquisition circuit is used to acquire the discharge current signal in the discharge circuit. The output terminal of the current slope detection circuit is connected to the second input terminal of the logic control circuit. The current slope detection circuit is used to determine whether the slope of the discharge current is within a preset current slope range and output a current detection signal.

[0011] In one optional embodiment, the control circuit of the discharge circuit further includes a discharge temperature detection circuit, wherein the input terminal of the discharge temperature detection circuit is connected to the discharge temperature signal, the output terminal of the discharge temperature detection circuit is connected to the third input terminal of the logic control circuit, and the discharge temperature detection circuit is used to determine whether the discharge temperature is within the preset temperature range and output a temperature detection signal.

[0012] In one optional embodiment, the control circuit of the discharge circuit further includes a signal isolation circuit, wherein the input terminal of the signal isolation circuit is connected to the output terminal of the logic control circuit, and the output terminal of the signal isolation circuit is connected to the input terminal of the drive circuit. The signal isolation circuit is used to isolate the logic control circuit and the drive circuit and to shield the interference at the output terminal of the logic control circuit.

[0013] In one optional embodiment, the control circuit of the discharge circuit further includes a discharge state feedback loop, wherein the first input terminal of the discharge state feedback loop is connected to the output terminal of the discharge voltage detection circuit, the second input terminal of the discharge state feedback loop is connected to the output terminal of the discharge current detection circuit, and the output terminal of the discharge state feedback loop is connected to the second input terminal of the logic control circuit. The discharge state feedback loop is used to output a discharge state signal based on the voltage detection signal and the current detection signal.

[0014] Secondly, this utility model provides a redundant active discharge circuit, comprising: a discharge circuit and a control circuit for the discharge circuit of the first aspect or any corresponding embodiment thereof, wherein the control terminal of the discharge circuit is connected to the output terminal of the drive circuit, the first terminal of the discharge circuit is connected to the positive bus, and the second terminal of the discharge circuit is connected to the negative bus; the input terminal of the discharge voltage detection circuit is connected to the discharge voltage signal between the positive and negative buses; the input terminal of the discharge current detection circuit is connected to the discharge current signal of the second terminal of the discharge circuit; and the drive circuit controls the discharge circuit to actively release the energy between the positive and negative buses based on the drive signal.

[0015] The redundant active discharge circuit provided by this utility model integrates a discharge voltage detection circuit and a discharge current detection circuit to construct a redundant monitoring system with dual state perception. This enables the drive circuit to accurately and reliably control the discharge process based on the comprehensive feedback of voltage and current signals. As a result, while ensuring that the energy of the high-voltage bus is released quickly and actively, the safety and reliability of the entire discharge process are significantly improved, and the safety risks that may be caused by the failure of a single path monitoring are effectively prevented.

[0016] In one optional embodiment, the discharge circuit includes a controllable switch and a discharge resistor, wherein a first end of the discharge resistor is connected to a first end of the controllable switch, and a second end of the discharge resistor is connected to a positive bus; the control end of the controllable switch is connected to the output end of the drive circuit, and a second end of the controllable switch is connected to a negative bus; the controllable switch is used to turn on based on a drive signal.

[0017] In one alternative implementation, the discharge resistor is a plastic-encapsulated thick-film power resistor. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a first configuration diagram of the control circuit of the discharge circuit according to an embodiment of the present utility model; Figure 2 This is a second configuration diagram of the control circuit of the discharge circuit according to an embodiment of the present utility model; Figure 3 This is a third configuration diagram of the control circuit of the discharge circuit according to an embodiment of the present utility model; Figure 4 This is a fourth configuration diagram of the control circuit of the discharge circuit according to an embodiment of the present utility model; Figure 5 This is a schematic diagram of the redundant active discharge circuit according to an embodiment of the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0021] It is understood that before using the technical solutions disclosed in the various embodiments of this utility model, users should be informed of the types, scope of use, and usage scenarios of the personal information involved in this utility model in an appropriate manner in accordance with relevant laws and regulations, and user authorization should be obtained.

[0022] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0023] The existing redundant active discharge circuit of the on-board motor controller does not have the function of detecting both the discharge voltage and discharge current of the high-voltage discharge circuit, which cannot meet the high-voltage safety requirements of new energy electric vehicles.

[0024] Therefore, this embodiment provides a control circuit for the discharge circuit, such as... Figure 1 As shown, it includes: discharge voltage detection circuit 1, discharge current detection circuit 2, logic control circuit 3, and drive circuit 4.

[0025] Figure 1 In the process, the input terminal of the discharge voltage detection circuit 1 is connected to the discharge voltage signal. The discharge voltage detection circuit 1 is used to determine whether the slope of the discharge voltage is within the preset voltage slope range and outputs the voltage detection signal. The input terminal of the discharge current detection circuit 2 is connected to the discharge current signal. The discharge current detection circuit 2 is used to determine whether the slope of the discharge current is within the preset current slope range and outputs the current detection signal.

[0026] Specifically, Figure 1In the process, the discharge voltage detection circuit 1 calculates the changing trend (i.e., slope) of the discharge voltage signal in real time, compares it with the preset slope range corresponding to the normal discharge voltage, and outputs a voltage detection signal. If the slope is too small, it means that the discharge circuit is open or the impedance is too large; if the slope is too large, it indicates that there is an abnormality such as a short circuit in the bus capacitor or its parallel components in the discharge circuit. For example, when it is determined that the slope of the discharge voltage is within the preset voltage slope range, a low-level voltage detection signal is output, indicating that the discharge state is normal; when it is determined that the slope of the discharge voltage is not within the preset voltage slope range, a high-level voltage detection signal is output, indicating that the discharge state is abnormal.

[0027] Specifically, Figure 1 Similar to the working principle of discharge voltage detection circuit 1, an abnormally high current indicates that the switch in the discharge circuit has broken down or the resistor has short-circuited; a current of zero or too low indicates that the circuit in the discharge circuit is open or the switch is not conducting. When discharge current detection circuit 2 determines that the slope of the discharge current is within the preset current slope range, it outputs a low-level current detection signal, indicating that the discharge state is normal; when it determines that the slope of the discharge current is not within the preset current slope range, it outputs a high-level current detection signal, indicating that the discharge state is abnormal.

[0028] Optionally, the determination of the preset voltage slope range and the preset current slope range is based on a healthy discharge curve obtained from a large amount of experimental data on the normal discharge process, which is the key to the accuracy of the diagnostic function.

[0029] Figure 1 In the circuit, the first input terminal of the logic control circuit 3 receives the active discharge signal, the second input terminal of the logic control circuit 3 is connected to the output terminal of the discharge voltage detection circuit 1 and the output terminal of the discharge current detection circuit 2, and the output terminal of the logic control circuit 3 is connected to the input terminal of the drive circuit 4. The logic control circuit is used to output the drive signal based on the built-in truth table; the drive circuit 4 is used to control the working state of the discharge circuit based on the drive signal of the logic control circuit 3.

[0030] Optionally, Figure 1 In the middle, the logic control circuit 3 simultaneously receives the voltage detection signal from the discharge voltage detection circuit 1 and the current detection signal from the discharge current detection circuit 2. Based on the levels of the voltage and current detection signals, it determines whether the discharge is normal and outputs a drive signal based on the built-in truth table. (1) When there is an active discharge signal, the logic control circuit 3 outputs a drive signal when it determines that the discharge voltage signal is normal based on the voltage detection signal or the discharge current signal is normal based on the current detection signal.

[0031] (2) When there is an active discharge signal, the logic control circuit 3 determines that the discharge voltage signal is normal based on the voltage detection signal and the discharge current signal is normal based on the current detection signal, and then outputs a drive signal.

[0032] (3) When there is an active discharge signal, the logic control circuit 3 determines that the discharge voltage signal is abnormal based on the voltage detection signal and determines that the discharge current signal is abnormal based on the current detection signal. When this happens, the logic control circuit 3 does not output a drive signal.

[0033] For example, when either the voltage detection signal or the current detection signal is at a low level, it indicates that the discharge is normal. The logic control circuit outputs a drive signal, which causes the control drive circuit to control the discharge circuit to conduct and perform active safety discharge. Conversely, when both the voltage detection signal and the current detection signal are at a high level, the logic control circuit will immediately block the drive signal. After the drive circuit does not receive the drive signal, it controls the discharge circuit to cut off the discharge function, thereby realizing redundant safety control based on dynamic behavior dual verification.

[0034] The control circuit of the discharge circuit provided by this utility model has dual redundant detection loops: a discharge voltage detection circuit and a discharge current detection circuit. These two detection circuits are mutually redundant. When both circuits detect an abnormality (such as no voltage change after a discharge command or an abnormal current surge), the logic control circuit can promptly cut off the output and shut down the discharge process, ensuring absolute reliability of state identification and avoiding misjudgments or missed judgments that may result from single-point monitoring failure. The control circuit of the discharge circuit provided by this utility model not only efficiently and quickly completes the discharge task under normal conditions, but also redundantly monitors the discharge status and controls the opening or closing of the discharge circuit, ensuring the safety of the discharge process.

[0035] In one alternative implementation, such as Figure 2 As shown, the discharge voltage detection circuit 1 includes a voltage divider circuit 11 and a voltage slope detection circuit 12. The input terminal of the voltage divider circuit 11 is connected to the discharge voltage signal, and the output terminal of the voltage divider circuit 11 is connected to the input terminal of the voltage slope detection circuit 12. The voltage divider circuit 11 is used to divide the discharge voltage signal. The output terminal of the voltage slope detection circuit 12 is connected to the second input terminal of the logic control circuit 3. The voltage slope detection circuit 12 is used to determine whether the slope of the discharge voltage is within a preset voltage slope range and output a voltage detection signal.

[0036] Specifically, Figure 2 In the process, the input terminal of the voltage divider circuit 11 is directly connected to the high-voltage discharge voltage signal between the positive and negative buses. The voltage is proportionally reduced through a precision resistor network, converting the higher bus voltage into a proportional low-voltage signal that can be safely processed by the subsequent low-voltage slope detection circuit 12.

[0037] Specifically, Figure 2 In this circuit, the voltage slope detection circuit 12 contains a differential or dynamic comparison circuit that can calculate and capture the rate of change (dV / dt) of the voltage divider signal in real time, i.e., the actual drop slope of the discharge voltage. The voltage slope detection circuit 12 can compare the calculated real-time slope value with a preset voltage slope range that represents the normal discharge rate, and then output a voltage detection signal, which is sent to the logic control circuit 3.

[0038] Specifically, Figure 2 In this system, the voltage detection signal level is a status indicator: when the real-time slope is within the preset range, the voltage detection signal is low, indicating "normal voltage drop"; when the real-time slope deviates from this range (too fast or too slow), the voltage detection signal immediately jumps to a high level, indicating "abnormal voltage drop", thus providing accurate and crucial judgment basis for subsequent system decisions regarding the health status of the discharge process.

[0039] Optionally, the voltage divider circuit includes multiple voltage divider resistors connected in series and / or in parallel.

[0040] In one alternative implementation, such as Figure 3 As shown, the discharge current detection circuit 2 includes a current acquisition circuit 21 and a current slope detection circuit 22. The input terminal of the current acquisition circuit 21 is connected to the discharge current signal, and the output terminal of the current acquisition circuit 21 is connected to the input terminal of the current slope detection circuit 22. The current acquisition circuit 21 is used to acquire the discharge current signal in the discharge circuit. The output terminal of the current slope detection circuit 22 is connected to the second input terminal of the logic control circuit 3. The current slope detection circuit 22 is used to determine whether the slope of the discharge current is within the preset current slope range and output a current detection signal.

[0041] Specifically, Figure 3 In this circuit, the input terminal of the current acquisition circuit 21 is connected to the actual discharge current signal through a precision sampling resistor connected in series in the discharge circuit. This resistor converts the current flowing through the circuit into a proportional, measurable low-voltage signal, thus completing the non-invasive and safe acquisition of the discharge current. This voltage signal is transmitted in real time to the input terminal of the next-stage current slope detection circuit 22.

[0042] Specifically, Figure 3 In the circuit, the current slope detection circuit 22 continuously analyzes the changing trend of the received signal through dynamic detection or calculation circuit, that is, calculates the rate of change of the discharge current (di / dt) in real time. The current slope detection circuit 22 compares the calculated real-time current slope with a preset current slope range that characterizes safe and effective discharge, and generates a digital current detection signal at its output terminal, which is then transmitted to the logic control circuit 3.

[0043] Specifically, Figure 3 In this system, the high or low level of the current detection signal is a status indicator: when the real-time current slope is within the preset range, the current detection signal is low, indicating that the discharge current is dynamically normal; when the real-time slope deviates from this range (too fast or too slow), the current detection signal switches to high, indicating that the discharge current is abnormal, thus providing the system with the ability to perform real-time and accurate diagnosis of the operating status of the discharge circuit.

[0044] In one alternative implementation, such as Figure 4 As shown, the control circuit of the discharge circuit also includes a discharge temperature detection circuit 5, wherein the input terminal of the discharge temperature detection circuit 5 is connected to the discharge temperature signal, and the output terminal of the discharge temperature detection circuit 5 is connected to the third input terminal of the logic control circuit 3. The discharge temperature detection circuit 5 is used to determine whether the discharge temperature is within the preset temperature range and outputs a temperature detection signal. Then, the logic control circuit 3 outputs a drive signal based on the built-in truth table.

[0045] Specifically, Figure 4 In the case of an active discharge signal, if the logic control circuit determines that the discharge voltage signal is normal based on the voltage detection signal and / or the discharge current signal is normal based on the current detection signal, and determines that the discharge temperature is abnormal based on the temperature detection signal, then the logic control circuit will not output a drive signal.

[0046] Specifically, Figure 4 In the process, when there is an active discharge signal, and the logic control circuit determines that the discharge voltage signal is normal based on the voltage detection signal and / or determines that the discharge current signal is normal based on the current detection signal, if the discharge temperature is determined to be normal based on the temperature detection signal, then the logic control circuit outputs a drive signal.

[0047] Specifically, Figure 4 In the case of an active discharge signal, if the logic control circuit determines that the discharge voltage signal is abnormal based on the voltage detection signal and the discharge current signal is abnormal based on the current detection signal, and determines that the discharge temperature signal is normal based on the temperature detection signal, the logic control circuit will not output a drive signal.

[0048] Specifically, Figure 4In this circuit, the discharge circuit control circuit incorporates a discharge temperature detection circuit 5, constructing a safety protection system that coordinates the monitoring of voltage, current, and temperature parameters. The input of the discharge temperature detection circuit 5 is connected to a temperature sensor signal installed on the discharge resistor or a key heat source in the discharge circuit, monitoring the temperature rise during the discharge process in real time. The discharge temperature detection circuit 5 compares the collected temperature signal with a preset safe temperature range to determine whether the discharge temperature is within the normal range, and finally outputs high or low level temperature detection signals, representing "normal" or "abnormal," to the logic control circuit 3.

[0049] Specifically, Figure 4 In the middle, logic control circuit 3 executes a strict set of multi-condition interlocking judgment logic, such as Figure 4 As shown: When logic control circuit 3 receives an active discharge signal, it simultaneously analyzes three detection signals: voltage, current, and temperature. If all three signals are deemed abnormal (including abnormal voltage slope, abnormal current slope, and excessive temperature), logic control circuit 3 immediately locks its output, preventing the discharge circuit from operating and achieving rapid safety protection. Only when the discharge temperature signal is deemed normal, and either the discharge voltage signal or the discharge current signal is deemed normal, does logic control circuit 3 confirm that the entire system is in a safe discharge state. At this point, it outputs a drive signal to initiate the normal active discharge process. This interlocking control mechanism based on triple parameter redundancy ensures that the discharge process can be reliably terminated when any single or multiple parameters are abnormal, significantly improving the overall safety and reliability of the system.

[0050] Specifically, Figure 4 In the discharge circuit, the control circuit also includes a signal isolation circuit 6, wherein the input terminal of the signal isolation circuit 6 is connected to the output terminal of the logic control circuit 3, and the output terminal of the signal isolation circuit 6 is connected to the input terminal of the drive circuit 4. The signal isolation circuit 6 is used to isolate the low-voltage signal output by the logic control circuit 3 from the high-voltage signal output by the drive circuit 4, and to prevent the high-voltage network signals of the drive circuit 4 and the subsequent circuit from causing electromagnetic interference to the low-voltage network signals of the logic control circuit 3 and the preceding circuit.

[0051] It should be noted that, to ensure the absolute reliability of the active discharge process under extreme high-voltage interference, the control loop of the discharge circuit also includes a critical signal isolation circuit. Its core function is to establish a robust electromagnetic barrier between the low-voltage control domain (logic control circuit) and the high-voltage power domain (drive circuit and subsequent power modules). On the one hand, it enables the safe and accurate transmission of low-voltage control signals to the high-voltage drive side. On the other hand, it can effectively block the severe electromagnetic interference generated by the drive circuit and power modules when the high-voltage high-current switching action is performed, preventing such noise from interfering with the sensitive logic control circuit through the signal path, thereby ensuring the stability and error-free operation of the entire control logic in a complex electromagnetic environment.

[0052] In one alternative implementation, such as Figure 4 As shown, the control circuit of the discharge circuit further includes: a discharge state feedback loop 7, wherein the first input terminal of the discharge state feedback loop 7 is connected to the output terminal of the discharge voltage detection circuit 1, the second input terminal of the discharge state feedback loop 7 is connected to the output terminal of the discharge current detection circuit 2, and the output terminal of the discharge state feedback loop 7 is connected to the second input terminal of the logic control circuit 3. The discharge state feedback loop 7 is used to output a discharge state signal based on the voltage detection signal and the current detection signal. The logic control circuit is used to output a drive signal based on the built-in truth table. The process also includes: when there is an active discharge signal, the logic control circuit determines that the discharge voltage is normal and / or the discharge current is normal based on the discharge state signal, and outputs a drive signal; when there is an active discharge signal, the logic control circuit determines that both the discharge voltage and the discharge current are abnormal based on the discharge state signal, and does not output a drive signal.

[0053] Specifically, the relationship between the high and low levels of the drive signal output by the logic control circuit and the high and low levels of the output levels of other circuits in the control circuit of the discharge circuit is shown in the built-in truth table of the logic control circuit in Table 1 below.

[0054] Table 1. Truth Table Built into Logic Control Circuit

[0055] Among them, the active discharge signal is L, which means there is no active discharge signal, and H means there is an active discharge signal; the voltage slope detection circuit signal is L, which means the discharge state is abnormal, and H means the discharge state is normal; the current slope detection circuit signal is L, which means the discharge state is abnormal, and H means the discharge state is normal; the discharge state feedback circuit signal is L, which means the discharge state is normal, and H means the discharge state is abnormal; the discharge temperature detection circuit signal is L, which means the discharge temperature is normal, and H means the discharge temperature is abnormal; the drive circuit signal is L, which means the active discharge function is not executed, and H means the active discharge function is executed.

[0056] This embodiment provides a redundant active discharge circuit, such as Figure 5 As shown, it includes: a discharge circuit 8 and a control circuit for the discharge circuit in the above embodiments and any optional embodiments thereof, wherein the control terminal of the discharge circuit 8 is connected to the output terminal of the drive circuit, the first terminal of the discharge circuit 8 is connected to the positive bus, and the second terminal of the discharge circuit 8 is connected to the negative bus; the input terminal of the discharge voltage detection circuit 1 is connected to the discharge voltage signal between the positive and negative buses; the input terminal of the discharge current detection circuit 2 is connected to the discharge current signal at the second terminal of the discharge circuit 8; and the drive circuit 4 controls the discharge circuit 8 to actively release the energy between the positive and negative buses based on the drive signal.

[0057] Specifically, Figure 5 The discharge circuit 8 includes a controllable switch Q1 and a discharge resistor RT1. The first end of the discharge resistor RT1 is connected to the first end of the controllable switch Q1, and the second end of the discharge resistor RT1 is connected to the positive bus DC+. The control end of the controllable switch Q1 is connected to the output end of the drive circuit 4, and the second end of the controllable switch Q1 is connected to the negative bus DC-. The controllable switch Q1 is used to conduct based on the drive signal, so that the high voltage on the inter-bus capacitor CV1 is released through the discharge resistor RT1 by heat. The conduction logic of the controllable switch Q1 is consistent with the above embodiment or any corresponding implementation method, and will not be repeated here.

[0058] Optionally, the sampling resistor Rs is the sampling part of the discharge current detection circuit 2, connected in series between the discharge circuit 8 and the negative bus DC-, to collect the discharge current in the circuit. The voltage divider resistors Rc1 and Rc2 are the sampling parts of the discharge voltage detection circuit 1.

[0059] Optionally, the discharge resistor is a plastic-encapsulated thick-film power resistor. From the perspective of installation and material cost, one end of the discharge resistor can be directly soldered to the circuit board of the discharge circuit through pins, which saves the connection harness and connectors compared with conventional discharge resistors, resulting in lower cost. The other end of the discharge resistor is fixed to the bottom plate of the controller housing where the discharge circuit is located by screws, and the water channels of the bottom plate of the housing can be used to dissipate heat from the discharge resistor.

[0060] The redundant active discharge circuit provided in this embodiment integrates a discharge voltage detection circuit and a discharge current detection circuit to construct a redundant monitoring system with dual state perception. This enables the drive circuit to accurately and reliably control the discharge process based on the comprehensive feedback of voltage and current signals. As a result, while ensuring that the energy of the high-voltage bus is released quickly and actively, the safety and reliability of the entire discharge process are significantly improved, and the safety risks that may be caused by the failure of a single path monitoring are effectively prevented.

[0061] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A control circuit for a discharge circuit, characterized in that, include: The circuit includes a discharge voltage detection circuit, a discharge current detection circuit, a logic control circuit, and a drive circuit. The discharge voltage detection circuit is connected to the input terminal of the discharge voltage signal. The discharge voltage detection circuit is used to determine whether the slope of the discharge voltage is within the preset voltage slope range and outputs the voltage detection signal. The discharge current detection circuit is connected to the discharge current signal at its input terminal. The discharge current detection circuit is used to determine whether the slope of the discharge current is within the preset current slope range and outputs a current detection signal. The first input terminal of the logic control circuit receives an active discharge signal, the second input terminal of the logic control circuit is connected to the output terminal of the discharge voltage detection circuit and the output terminal of the discharge current detection circuit, the output terminal of the logic control circuit is connected to the input terminal of the drive circuit, and the logic control circuit is used to output a drive signal based on a built-in truth table. The driving circuit is used to control the operating state of the discharge circuit based on the driving signal of the logic control circuit.

2. The control circuit of the discharge circuit according to claim 1, characterized in that, The discharge voltage detection circuit includes: a voltage divider circuit and a voltage slope detection circuit, wherein... The input terminal of the voltage divider circuit is connected to the discharge voltage signal, and the output terminal of the voltage divider circuit is connected to the input terminal of the voltage slope detection circuit. The voltage divider circuit is used to divide the discharge voltage signal. The output terminal of the voltage slope detection circuit is connected to the second input terminal of the logic control circuit. The voltage slope detection circuit is used to determine whether the slope of the discharge voltage is within the preset voltage slope range and outputs a voltage detection signal.

3. The control circuit of the discharge circuit according to claim 2, characterized in that, The voltage divider circuit includes multiple voltage divider resistors connected in series and / or in parallel.

4. The control circuit of the discharge circuit according to claim 1, characterized in that, The discharge current detection circuit includes: a current acquisition circuit and a current slope detection circuit, wherein... The input terminal of the current acquisition circuit is connected to the discharge current signal, and the output terminal of the current acquisition circuit is connected to the input terminal of the current slope detection circuit. The current acquisition circuit is used to acquire the discharge current signal in the discharge circuit. The output terminal of the current slope detection circuit is connected to the second input terminal of the logic control circuit. The current slope detection circuit is used to determine whether the slope of the discharge current is within the preset current slope range and outputs a current detection signal.

5. The control circuit of the discharge circuit according to claim 1, characterized in that, Also includes: The discharge temperature detection circuit, in which, The discharge temperature detection circuit has a discharge temperature signal input and an output connected to the third input of the logic control circuit. The discharge temperature detection circuit is used to determine whether the discharge temperature is within a preset temperature range and outputs a temperature detection signal.

6. The control circuit of the discharge circuit according to claim 1, characterized in that, Also includes: Signal isolation circuit, wherein, The input terminal of the signal isolation circuit is connected to the output terminal of the logic control circuit, and the output terminal of the signal isolation circuit is connected to the input terminal of the driving circuit. The signal isolation circuit is used to isolate the logic control circuit and the driving circuit, and to shield the interference at the output terminal of the logic control circuit.

7. The control circuit of the discharge circuit according to claim 1, characterized in that, Also includes: Discharge state feedback loop, wherein, The first input terminal of the discharge state feedback loop is connected to the output terminal of the discharge voltage detection circuit, the second input terminal of the discharge state feedback loop is connected to the output terminal of the discharge current detection circuit, and the output terminal of the discharge state feedback loop is connected to the second input terminal of the logic control circuit. The discharge state feedback loop is used to output a discharge state signal based on the voltage detection signal and the current detection signal.

8. A redundant active discharge circuit, characterized in that, include: The discharge circuit and the control circuit of the discharge circuit according to any one of claims 1 to 7, wherein, The control terminal of the discharge circuit is connected to the output terminal of the drive circuit, the first terminal of the discharge circuit is connected to the positive bus, and the second terminal of the discharge circuit is connected to the negative bus. The input terminal of the discharge voltage detection circuit is connected to the discharge voltage signal between the positive and negative buses; The input terminal of the discharge current detection circuit is connected to the discharge current signal at the second terminal of the discharge circuit; The driving circuit controls the discharge circuit to actively release the energy between the positive and negative buses based on the driving signal.

9. The redundant active discharge circuit according to claim 8, characterized in that, The discharge circuit includes: a controllable switch and a discharge resistor, wherein, The first end of the discharge resistor is connected to the first end of the controllable switch, and the second end of the discharge resistor is connected to the positive busbar. The control terminal of the controllable switch is connected to the output terminal of the drive circuit, and the second terminal of the controllable switch is connected to the negative bus. The controllable switch is used to turn on based on the drive signal.

10. The redundant active discharge circuit according to claim 9, characterized in that, The discharge resistor is a plastic-encapsulated thick-film power resistor.

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