Motor drive control circuit, electrical system and vehicle

Abstract

A motor drive control circuit, an electrical system and a vehicle relate to the technical field of motor drive. The motor drive control circuit comprises a drive circuit used for generating multiple paths of PWM drive signals to control a power bridge circuit so as to drive a motor; the sampling circuit is used for sampling current flowing through the motor and generating a corresponding sampling voltage signal; the current limiting circuit is used for comparing the sampling voltage signal with a current limiting reference voltage and outputting a protection trigger signal in response to the fact that at least one upper bridge arm of the power bridge circuit is in a conducting state when the sampling voltage signal is greater than the current limiting reference voltage; the driving circuit responds to the protection trigger signal, all upper bridge arms of the power bridge circuit are closed, and all lower bridge arms are disconnected; or all lower bridge arms of the power bridge circuit are closed, and all upper bridge arms are disconnected. According to the motor driving control circuit, the electrical system and the vehicle, current limiting protection can be carried out on the motor driving circuit, and the reliability and safety of the electrical system and the vehicle are improved.

Description

Technical Field

[0001] This disclosure relates to the field of motor drive technology, and more specifically, to a motor drive control circuit, electrical system, and vehicle. Background Technology

[0002] When a motor malfunctions during startup or operation, such as when it stalls or experiences a phase-to-phase short circuit, it may generate a transient inrush current that far exceeds the rated value, leading to equipment damage, circuit overload, or system instability.

[0003] In various systems that require control of motor start-up, operation, or protection, effective overcurrent protection is crucial to ensuring system reliability and safety. Summary of the Invention

[0004] This disclosure provides a motor drive control circuit, an electrical system, and a vehicle, which can provide current limiting protection for the motor drive circuit and improve the reliability and safety of the electrical system and the vehicle.

[0005] According to one aspect of this disclosure, a motor drive control circuit is provided, comprising: The drive circuit is used to generate multiple PWM drive signals to control the power bridge circuit, thereby driving the motor. The sampling circuit is used to sample the current flowing through the motor and generate a corresponding sampling voltage signal; The current limiting circuit is used to compare the sampled voltage signal with the current limiting reference voltage, and when the sampled voltage signal is greater than the current limiting reference voltage, it outputs a protection trigger signal in response to at least one upper bridge arm of the power bridge circuit being in the on state. In response to a protection trigger signal, the drive circuit closes all upper arms of the power bridge circuit and disconnects all lower arms; or closes all lower arms of the power bridge circuit and disconnects all upper arms.

[0006] In one exemplary embodiment of this disclosure, the current limiting circuit includes a latching unit, which is used to maintain a protection trigger signal in response to at least one upper bridge arm of the power bridge circuit being in a conducting state when the sampled voltage signal is greater than the current limiting reference voltage.

[0007] In one exemplary embodiment of this disclosure, the current limiting circuit includes an OR logic unit, a comparator, and a current limiting switch; multiple input terminals of the OR logic unit are respectively connected to multiple upper arms of the power bridge circuit; the first input terminal of the comparator is connected to a sampled voltage signal, and the second input terminal of the comparator is connected to a current limiting reference voltage; The control terminal of the current limiting switch is connected to the output terminal of the comparator and the output terminal of the OR logic unit; the current limiting switch is used to open when the sampled voltage signal is greater than the current limiting reference voltage and the OR logic unit is turned on, so as to output a protection trigger signal; the current limiting switch is turned off when the OR logic unit is turned off.

[0008] In one exemplary embodiment of this disclosure, the logic unit includes a plurality of diodes, which are respectively connected between a plurality of upper arms of the power bridge circuit and the control terminal of the current limiting switch; the logic unit is turned on when any one upper arm of the power bridge circuit is turned on, or the logic unit is turned off when all upper arms of the power bridge circuit are turned off.

[0009] In one exemplary embodiment of this disclosure, the latching unit includes a latching diode; the positive terminal of the latching diode is connected to the output terminal of the comparator, and the negative terminal of the latching diode is connected to the first input terminal of the comparator.

[0010] In one exemplary embodiment of this disclosure, the driving circuit includes a controller and a driving chip; the controller is used to generate multiple raw PWM signals; the driving chip is used to generate multiple PWM drive signals based on the multiple raw PWM signals to control the power bridge circuit. The current limiting circuit is connected between the controller and the driver chip. When the sampled voltage signal is greater than the current limiting reference voltage, the current limiting circuit responds to at least one of the upper bridge arms of the original PWM signal corresponding to the upper bridge arm of the power bridge circuit being in the on state and outputs a protection trigger signal.

[0011] In one exemplary embodiment of this disclosure, the driver chip has a protection control pin; the protection control pin is connected to the controller and the current limiting circuit; in response to a protection trigger signal, the protection control pin closes all upper bridge arms of the power bridge circuit and disconnects all lower bridge arms; or closes all lower bridge arms of the power bridge circuit and disconnects all upper bridge arms.

[0012] In one exemplary embodiment of this disclosure, the protection control pin is active low; the current limiting circuit includes a current limiting switch, which pulls down the level of the protection control pin when the current limiting switch is turned on.

[0013] In one exemplary embodiment of this disclosure, the sampling circuit includes a sampling resistor and a sampling amplifier; the sampling resistor is connected in series in the loop of the power bridge circuit; the sampling amplifier is used to acquire the voltage across the sampling resistor and amplify it to generate a sampling voltage signal.

[0014] In one exemplary embodiment of this disclosure, the current limiting circuit includes a pull-down resistor, the first end of which is connected to the output of the OR logic unit, and the second end of which is grounded.

[0015] In one exemplary embodiment of this disclosure, the power bridge circuit includes three upper bridge arm MOSFETs and three lower bridge arm MOSFETs; the drains of the three upper bridge arm MOSFETs are connected to the positive terminal of the power supply, the sources of the three upper bridge arm MOSFETs are respectively connected to the drains of the three lower bridge arm MOSFETs, and are respectively connected to the three-phase windings of the motor; the sources of the three lower bridge arm MOSFETs are connected to the negative terminal of the power supply.

[0016] According to another aspect of this disclosure, an electrical system is provided, including a power supply module, a motor, and a motor drive control circuit of any of the foregoing; the power supply module supplies power to the motor through the drive circuit.

[0017] According to another aspect of this disclosure, a vehicle is provided, including the electrical system of any of the foregoing.

[0018] The motor drive control circuit disclosed herein can provide current-limiting protection for the motor drive circuit, improving the reliability and safety of the electrical system. The current-limiting circuit can trigger the drive circuit to enter the current-limiting protection state at the hardware level, resulting in a fast response speed, which is beneficial for handling sudden overcurrent scenarios and suppressing transient inrush currents. Furthermore, the current-limiting circuit determines whether to perform current-limiting action by comparing the sampled voltage signal with the current-limiting reference voltage. Therefore, the overcurrent threshold of the motor can be adjusted by changing the design of the sampling resistor in the sampling circuit or by changing the current-limiting reference voltage, improving design flexibility.

[0019] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0020] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0021] Figure 1 This is a schematic diagram of an exemplary embodiment of the motor drive control circuit of this disclosure.

[0022] Explanation of reference numerals in the attached figures: 100, Motor; 200, Controller; 300, Driver Chip. Detailed Implementation

[0023] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore detailed descriptions of them will be omitted. Furthermore, the drawings are merely illustrative of this disclosure and are not necessarily drawn to scale.

[0024] Unless otherwise specified or stated, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “a,” “an,” “the,” “the,” and “at least one” are used to indicate the presence of one or more elements / components / etc.; the terms “comprising” and “having” are used to indicate an open-ended inclusion and to mean that there may be other elements / components / etc. in addition to those listed; the terms “first” and “second” are used only as illustrative marks and are not intended to limit the number, importance, or order of the objects.

[0025] For example, without departing from the scope of this application, the first end may also be referred to as the second end, and the second end may also be referred to as the first end. Depending on the context, “in the case of” can be interpreted as “when”, “if”, or “in response to determination”.

[0026] In the following description, suffixes such as "module" or "unit" used to denote elements are used only for the purposes of this application and have no specific meaning in themselves. Therefore, "module" or "unit" can be used interchangeably.

[0027] According to one aspect of this disclosure, a motor drive control circuit is provided, including a drive circuit, a sampling circuit, and a current limiting circuit. The drive circuit generates multiple PWM (Pulse Width Modulation) drive signals to control a power bridge circuit, thereby driving a motor 100. The sampling circuit samples the current flowing through the motor 100 and generates a corresponding sampling voltage signal. The current limiting circuit compares the sampling voltage signal with a current-limiting reference voltage, and when the sampling voltage signal is greater than the current-limiting reference voltage, outputs a protection trigger signal in response to at least one upper arm of the power bridge circuit being in a conducting state. In response to the protection trigger signal, the drive circuit closes all upper arms of the power bridge circuit and opens all lower arms; or closes all lower arms of the power bridge circuit and opens all upper arms.

[0028] Specifically, the drive circuit can control the on / off state of each switching device in the power bridge circuit through multiple PWM drive signals, thereby converting the energy of the DC power supply into three-phase AC power to drive the motor 100. The sampling circuit can convert the current flowing through the motor 100 into a sampling voltage signal to achieve real-time monitoring of the operating status of the motor 100. The current limiting circuit can compare the sampling voltage signal with the current limiting reference voltage. When the sampling voltage signal is greater than the current limiting reference voltage, it indicates that the current of the motor 100 has exceeded the safety threshold. At this time, if at least one upper bridge arm of the power bridge circuit is in the on state, the current limiting circuit can output a protection trigger signal to make the drive circuit enter the active short circuit (ASC) protection state, closing all upper bridge arms of the power bridge circuit and opening all lower bridge arms; or closing all lower bridge arms of the power bridge circuit and opening all upper bridge arms, so that the three-phase windings of the motor 100 are short-circuited together, thereby rapidly attenuating the current in the motor 100 and preventing it from rising further.

[0029] The motor drive control circuit disclosed herein can provide current-limiting protection for the motor drive circuit, improving the reliability and safety of the electrical system. The current-limiting circuit can trigger the drive circuit to enter the current-limiting protection state at the hardware level, resulting in a fast response speed, which is beneficial for handling sudden overcurrent scenarios and suppressing transient inrush currents. Furthermore, the current-limiting circuit determines whether to perform current-limiting action by comparing the sampled voltage signal with the current-limiting reference voltage. Therefore, by changing the design of the sampling resistor in the sampling circuit or changing the current-limiting reference voltage, the overcurrent threshold of the motor 100 can be adjusted, improving design flexibility.

[0030] For example, refer to Figure 1 As shown, the drive circuit includes a controller 200 and a drive chip 300. The controller 200 generates multiple raw PWM signals; the drive chip 300 generates multiple PWM drive signals based on the raw PWM signals to control the power bridge circuit. For example, the controller 200 can be a microcontroller unit (MCU) or system-on-chip (SoC) of a motor controller, generating multiple raw PWM signals by running a field-oriented control (FOC) algorithm. The drive chip 300 acts as a power interface, receiving the raw PWM signals from the controller 200 and amplifying the voltage and current to generate PWM drive signals sufficient to drive the switching devices in the power bridge circuit.

[0031] refer to Figure 1As shown, the controller 200 outputs six raw PWM signals via MCU_HS1_DO, MCU_HS2_DO, MCU_HS3_DO, MCU_LS1_DO, MCU_LS2_DO, and MCU_LS3_DO. The driver chip 300 converts these six raw PWM signals into PWM drive signals that can drive the switching devices in the power bridge circuit, namely HS1_Gate, HS2_Gate, HS3_Gate, LS1_Gate, LS2_Gate, and LS3_Gate. Among them, HS1_Gate, HS2_Gate, and HS3_Gate are used to drive the switching devices of the upper arm of the power bridge circuit; LS1_Gate, LS2_Gate, and LS3_Gate are used to drive the switching devices of the lower arm of the power bridge circuit.

[0032] Specifically, the power bridge circuit may include three upper bridge arm switches, Q1, Q2, and Q3; and three lower bridge arm switches, Q4, Q5, and Q6, which together constitute a three-phase bridge inverter circuit. The upper and lower bridge arm switches can be metal-oxide-semiconductor field-effect transistors (MOSFETs) or transistors. Taking MOSFETs as an example, refer to [reference needed]. Figure 1 As shown, the drains of Q1, Q2, and Q3 are connected to the positive terminal VBAT of the power supply, and the sources of Q1, Q2, and Q3 are connected to the drains of Q4, Q5, and Q6, respectively, and then connected to the three-phase windings (U, V, W) of motor 100. The sources of Q4, Q5, and Q6 are grounded together. The gate of Q1 is controlled by HS1_Gate; the gate of Q2 is controlled by HS2_Gate; the gate of Q3 is controlled by HS3_Gate; the gate of Q4 is controlled by LS1_Gate; the gate of Q5 is controlled by LS2_Gate; and the gate of Q6 is controlled by LS3_Gate. Q1, Q2, Q3, Q4, Q5, and Q6 activate according to the waveform generation algorithm of controller 200, driving motor 100 to run.

[0033] In one exemplary embodiment of this disclosure, reference is made to Figure 1 As shown, the sampling circuit includes a sampling resistor Rshunt, which is connected in series in the loop of the power bridge circuit. For example, the sampling resistor Rshunt is connected between the source of the lower bridge arm switches Q4, Q5, and Q6 and ground. All or part of the current flowing through the motor 100 flows through the sampling resistor Rshunt, generating a voltage drop, the value of which is Iload. Rshunt, where Iload is the sampling current. The sampling circuit also includes a sampling amplifier, which can acquire and amplify the voltage drop across the sampling resistor Rshunt, and output the sampling voltage signal Current_AIN to the controller 200. Current_AIN = Iload Rshunt Gain, where Gain is the amplification factor of the sampling amplifier. By sampling the voltage signal Current_AIN, the real-time current in the motor circuit can be accurately reflected. In some embodiments, the sampling amplifier can be located inside the driver chip 300. In other embodiments, the sampling amplifier can also be set independently.

[0034] For example, the driver chip 300 has a protection control pin nASC. (See reference...) Figure 1 As shown, the protection control pin nASC is connected to the controller 200 and the current limiting circuit. The protection control pin is active low. When the motor 100 is operating normally, the nASC signal sent by the controller 200 to the driver chip 300 is high. When the protection trigger signal output by the current limiting circuit is valid, it pulls the level of the protection control pin nASC low. After detecting the low level of the protection control pin nASC, the driver chip 300 can execute its built-in active short-circuit protection program, forcing the power bridge circuit into the aforementioned ASC state, closing all upper bridge arm switches Q1, Q2, and Q3 of the power bridge circuit, and opening all lower bridge arm switches Q4, Q5, and Q6; or closing all lower bridge arm switches Q4, Q5, and Q6 of the power bridge circuit, and opening all upper bridge arm switches Q1, Q2, and Q3. In this exemplary embodiment, the protection control pin nASC is built into the driver chip 300. The active short-circuit protection of the power bridge circuit is achieved through the driver chip 300, which improves response speed and reliability and simplifies external circuit design. For example, the current limiting circuit may include a current limiting switch Q0, which is connected in series between the protection control pin nASC and ground. The protection trigger signal output by the current limiting circuit can be implemented through the current limiting switch Q0. When the current limiting switch Q0 is turned on, it can pull down the level of the protection control pin nASC. For example, refer to Figure 1 As shown, a first resistor R1 is connected in series between the controller 200 and the protection control pin nASC to ensure that the protection control pin nASC maintains the high level provided by the controller 200 under non-current limiting conditions.

[0035] For example, a current limiting circuit is connected between the controller 200 and the driver chip 300. The current limiting circuit outputs a protection trigger signal when at least one of the original PWM signals corresponding to the upper arm of the power bridge circuit is in a conducting state, in response to the sampling voltage signal Current_AIN being greater than the current limiting reference voltage Vref. For example, when any one of the three paths MCU_HS1_DO, MCU_HS2_DO, and MCU_HS3_DO corresponding to the upper arm of the power bridge circuit in the original PWM signal is in a conducting state, and the sampling voltage signal Current_AIN is greater than the current limiting reference voltage Vref, the current limiting circuit outputs a protection trigger signal. The current limiting circuit monitors the conducting state of the upper arm by monitoring the signal corresponding to the upper arm in the original PWM signal of the controller 200. This allows the motor drive control circuit of this disclosure to achieve protection functions through external additional circuitry without changing the control logic within the driver chip 300 or the circuit architecture of the driver chip 300 controlling the motor 100 through the power bridge circuit, thus improving system compatibility and portability.

[0036] In one exemplary embodiment of this disclosure, the current limiting circuit includes an OR logic unit, a comparator U1, and a current limiting switch Q0. Multiple input terminals of the OR logic unit are respectively connected to multiple upper arms of a power bridge circuit; the first input terminal of the comparator U1 is connected to the sampled voltage signal Current_AIN, and the second input terminal of the comparator U1 is connected to the current limiting reference voltage Vref. The control terminal of the current limiting switch Q0 is connected to the output terminal of the comparator U1 and the output terminal of the OR logic unit; the current limiting switch Q0 is turned on when the sampled voltage signal Current_AIN is greater than the current limiting reference voltage Vref and the OR logic unit is turned on, to output a protection trigger signal; the current limiting switch Q0 is turned off when the OR logic unit is turned off.

[0037] Specifically, refer to Figure 1As shown, the OR logic unit may include multiple diodes. For example, the OR logic unit may include D1, D2, and D3. The anode of D1 is connected to the original PWM signal MCU_HS1_DO used to generate the control signal for switching Q1; the anode of D2 is connected to the original PWM signal MCU_HS2_DO used to generate the control signal for switching Q2; and the anode of D3 is connected to the original PWM signal MCU_HS3_DO used to generate the control signal for switching Q3. The cathodes of D1, D2, and D3 are connected to a common point, forming the output of the OR logic unit. When any one of the three upper-side control signals MCU_HS1_DO, MCU_HS2_DO, and MCU_HS3_DO is high, its corresponding diode will conduct, thus generating a high level at the common output. When all three upper-side control signals MCU_HS1_DO, MCU_HS2_DO, and MCU_HS3_DO are low, the level at the common output is low.

[0038] The first input terminal of comparator U1 can be its non-inverting input terminal, connected to the sampling voltage signal Current_AIN; the second input terminal of comparator U1 can be its inverting input terminal, connected to the current-limiting reference voltage Vref. The current-limiting switch Q0 can be an N-MOSFET or an NPN transistor. The control terminal (such as the gate or base) of the current-limiting switch Q0 is connected to the output terminal of comparator U1 and the output terminal of the AND-OR logic unit. For example, refer to... Figure 1 As shown, a second resistor R2 is connected in series between the first input terminal of comparator U1 and the output terminal of the sampling amplifier to improve the anti-interference capability of comparator U1. Similarly, a current-limiting resistor R4 is connected in series between the output terminal of the OR logic unit and the control terminal of the current-limiting switch Q0 to prevent overcurrent damage to the current-limiting switch Q0 or comparator U1.

[0039] When the motor 100 is operating normally, if the sampled voltage signal Current_AIN does not exceed the reference voltage Vref, the comparator U1 outputs a low level, the current limiting switch Q0 is not turned on, and the protection control pin nASC of the driver chip 300 remains at the high level given by the controller 200, and the current limiting protection is not triggered.

[0040] When an overcurrent occurs, if the operating current in the power bridge circuit abnormally increases and the sampled voltage signal Current_AIN exceeds the current-limiting reference voltage Vref, the output state of comparator U1 changes, and comparator U1 outputs a high-impedance state. At this time, if any one of the three upper bridge arm control signals (MCU_HS1_DO, MCU_HS2_DO, and MCU_HS3_DO) is high, or the logic unit is turned on, a high-level signal is sent to the control terminal of the current-limiting switch Q0, causing Q0 to turn on and output a protection trigger signal, pulling the protection control pin nASC of the driver chip 300 low. However, if all upper bridge arm control signals are low, and the upper bridge arm of motor 100 is not turned on, then the logic unit has no output, the current-limiting switch Q0 remains closed, and the current-limiting protection is not triggered. During the upper bridge's on-time, current flows through the upper bridge to motor 100; if a transient overcurrent surge occurs, the motor may burn out. The current limiting circuit of this exemplary embodiment can limit the current only when an overcurrent occurs during the conduction cycle of the motor 100 bridge, thereby improving the accuracy of protection.

[0041] Furthermore, when all control signals of the upper bridge arm return to low level, the current limiting switch Q0 closes, causing the protection control pin nASC of the driver chip 300 to return to the high level provided by the driver chip 300, exiting the ASC protection state. In the next PWM cycle, the comparator U1 compares the sampled voltage signal Current_AIN with the current limiting reference voltage Vref again. If an overcurrent occurs again, and the sampled voltage signal Current_AIN is greater than the current limiting reference voltage Vref, then the ASC protection state for one PWM cycle is entered again. If no overcurrent occurs, and the sampled voltage signal Current_AIN is less than the current limiting reference voltage Vref, then no current limiting action is performed. Therefore, the motor drive control circuit of this disclosure can determine the current limiting condition and execute the current limiting action on a PWM cycle basis, limiting the sampled current Iload to below the current limiting value Isthreshold through the current limiting reference voltage Vref. Specifically, the current limiting reference voltage Vref and the current limiting value Isthreshold satisfy the relationship Vref = Isthreshold. Rshunt Gain, where Gain is the amplification factor of the sampling amplifier. Each current-limiting action can be limited to one PWM cycle to ensure that the loop current does not exceed the current-limiting value Isthreshold. Once the condition that triggered the current-limiting action disappears in the next PWM cycle, the system can automatically resume normal modulation, thus preventing the output from being completely shut down due to the triggering of the current-limiting action. As long as abnormal overcurrent exists, the output current will be limited to fluctuate around the current-limiting value Isthreshold, ensuring the continuity of system operation.

[0042] In one exemplary embodiment of this disclosure, the current limiting circuit includes a latching unit. The latching unit is used to maintain the protection trigger signal in response to at least one upper arm of the power bridge circuit being in a conducting state when the sampled voltage signal is greater than the current limiting reference voltage. The latching unit ensures that even if the sampled current value Iload drops instantaneously due to the protection action during the current PWM cycle that triggers the ASC protection state, the protection state will not be immediately released, thus guaranteeing the effectiveness and integrity of the current limiting action within one PWM cycle.

[0043] For example, refer to Figure 1 As shown, the latching unit includes a latching diode D4. The anode of the latching diode D4 is connected to the output of comparator U1, and the cathode of the latching diode D4 is connected to the first input of comparator U1. When comparator U1 outputs a high-impedance state due to overcurrent and is pulled high by any one of the three upper bridge arm control signals MCU_HS1_DO, MCU_HS2_DO, and MCU_HS3_DO, this high level can be forward-biased through the latching diode D4, thereby raising the potential of the first input of comparator U1 to above the current-limiting reference voltage Vref. Even if the original overcurrent is attenuated due to protection action and the sampling current Iload becomes 0V, comparator U1 can still maintain the potential of the first input above the current-limiting reference voltage Vref, locking the current current-limiting protection state until all upper bridge arm control signals become low.

[0044] In one exemplary embodiment of this disclosure, the current limiting circuit includes a pull-down resistor R3. The first end of the pull-down resistor R3 is connected to the output of the OR logic unit, and the second end of the pull-down resistor R3 is grounded. When all upper bridge arm control signals are low, the pull-down resistor R3 ensures that the control terminal of the current limiting switch Q0 is reliably pulled low, preventing noise from causing the current limiting switch Q0 to mis-turn on, thus enhancing the circuit's anti-interference capability and static stability.

[0045] According to another aspect of this disclosure, an electrical system is provided. It includes a power module, a motor 100, and a motor drive control circuit of any of the foregoing embodiments; the power module supplies power to the motor 100 through the drive circuit. Exemplarily, the electrical system of this disclosure can be a vehicle electrical system, the power module can include a vehicle power battery, and the motor 100 can include a drive motor. Exemplarily, the motor 100 can also include auxiliary motors such as a power steering motor, an air conditioning fan motor, and a cooling water pump motor.

[0046] According to another aspect of this disclosure, a vehicle is provided, including the electrical system of any of the foregoing embodiments. Specifically, the vehicle can be a hybrid vehicle, a non-hybrid vehicle, an electric vehicle, a fuel cell vehicle, or a vehicle with other power types. The vehicle can be an autonomous vehicle, a semi-autonomous vehicle, or a non-autonomous vehicle. The vehicle may also include a powertrain, chassis, body, instruments, etc., which will not be listed here.

[0047] The electrical system and vehicle disclosed herein have higher safety when facing transient overcurrent because the motor drive control circuit has a fast response and high reliability hardware current limiting protection function.

[0048] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the appended claims.

Claims

1. A motor drive control circuit, characterized in that, include: A drive circuit is used to generate multiple PWM drive signals to control the power bridge circuit, thereby driving the motor (100). A sampling circuit is used to sample the current flowing through the motor (100) and generate a corresponding sampling voltage signal; A current limiting circuit is used to compare the sampled voltage signal with a current limiting reference voltage, and when the sampled voltage signal is greater than the current limiting reference voltage, in response to at least one upper bridge arm of the power bridge circuit being in a conducting state, outputs a protection trigger signal. In response to the protection trigger signal, the drive circuit closes all upper bridge arms of the power bridge circuit and disconnects all lower bridge arms; or closes all lower bridge arms of the power bridge circuit and disconnects all upper bridge arms.

2. The motor drive control circuit according to claim 1, characterized in that, The current limiting circuit includes a latching unit, which is used to maintain the protection trigger signal in response to at least one upper bridge arm of the power bridge circuit being in a conducting state when the sampled voltage signal is greater than the current limiting reference voltage.

3. The motor drive control circuit according to claim 2, characterized in that, The current limiting circuit includes an OR logic unit, a comparator, and a current limiting switch; multiple input terminals of the OR logic unit are respectively connected to multiple upper arms of the power bridge circuit; the first input terminal of the comparator is connected to the sampled voltage signal, and the second input terminal of the comparator is connected to the current limiting reference voltage. The control terminal of the current limiting switch is connected to the output terminal of the comparator and the output terminal of the OR logic unit; the current limiting switch is used to turn on when the sampled voltage signal is greater than the current limiting reference voltage and the OR logic unit is turned on, so as to output the protection trigger signal; the current limiting switch is turned off when the OR logic unit is turned off.

4. The motor drive control circuit according to claim 3, characterized in that, The OR logic unit includes multiple diodes, which are respectively connected between multiple upper arms of the power bridge circuit and the control terminal of the current limiting switch; the OR logic unit is turned on when any one upper arm of the power bridge circuit is turned on, and the OR logic unit is turned off when all upper arms of the power bridge circuit are turned off.

5. The motor drive control circuit according to claim 3, characterized in that, The latching unit includes a latching diode; the positive terminal of the latching diode is connected to the output terminal of the comparator, and the negative terminal of the latching diode is connected to the first input terminal of the comparator.

6. The motor drive control circuit according to any one of claims 1 to 5, characterized in that, The driving circuit includes a controller (200) and a driving chip (300); the controller (200) is used to generate multiple raw PWM signals; the driving chip (300) is used to generate multiple PWM driving signals according to the multiple raw PWM signals to control the power bridge circuit; The current limiting circuit is connected between the controller (200) and the driver chip (300); the current limiting circuit is used to output the protection trigger signal when the sampled voltage signal is greater than the current limiting reference voltage, in response to at least one of the original PWM signals corresponding to the upper bridge arm of the power bridge circuit being in a conducting state.

7. The motor drive control circuit according to claim 6, characterized in that, The driver chip (300) has a protection control pin; the protection control pin is connected to the controller (200) and the current limiting circuit; the protection control pin responds to the protection trigger signal by closing all upper bridge arms of the power bridge circuit and opening all lower bridge arms; or closing all lower bridge arms of the power bridge circuit and opening all upper bridge arms.

8. The motor drive control circuit according to claim 7, characterized in that, The protection control pin is active low; the current limiting circuit includes a current limiting switch, which pulls the level of the protection control pin low when the current limiting switch is turned on.

9. The motor drive control circuit according to claim 1, characterized in that, The sampling circuit includes a sampling resistor and a sampling amplifier; the sampling resistor is connected in series in the loop of the power bridge circuit; the sampling amplifier is used to acquire the voltage across the sampling resistor and amplify it to generate the sampling voltage signal.

10. The motor drive control circuit according to claim 3, characterized in that, The current limiting circuit includes a pull-down resistor, the first end of which is connected to the output of the OR logic unit, and the second end of which is grounded.

11. The motor drive control circuit according to claim 1, characterized in that, The power bridge circuit includes three upper bridge arm MOSFETs and three lower bridge arm MOSFETs; the drains of the three upper bridge arm MOSFETs are connected to the positive terminal of the power supply, the sources of the three upper bridge arm MOSFETs are respectively connected to the drains of the three lower bridge arm MOSFETs, and are respectively connected to the three-phase windings of the motor (100); the sources of the three lower bridge arm MOSFETs are connected to the negative terminal of the power supply.

12. An electrical system, characterized in that, It includes a power supply module, a motor (100), and a motor drive control circuit according to any one of claims 1 to 11; the power supply module supplies power to the motor (100) through the drive circuit.

13. A vehicle, characterized in that, Includes the electrical system as described in claim 12.

Images