Three-phase motor safety turn-off control system and control method thereof

Abstract

The invention belongs to the technical field of automobile electric control, and particularly relates to a three-phase motor safety turn-off control system and a control method thereof, and the three-phase motor safety turn-off control system comprises a motor fault monitoring unit, a system state monitoring unit, a logic control unit, a microcontroller unit, a driving unit and a three-phase motor. Firstly, fault monitoring signals such as overvoltage of a driving power supply and overcurrent of a motor can be obtained and distinguished; secondly, after the fault is monitored, the safe turn-off control system can provide rapid and synchronous U, V and W three-phase turn-off control signals and drive enable / disable control signals to act on a three-phase motor drive control end, microsecond-level fault response and three-phase motor turn-off control are achieved, the overvoltage and overcurrent risks of a drive circuit under the fault are effectively avoided, and the service life of the drive circuit is prolonged. And meanwhile, the requirement of a system for quickly entering a safe state after failure is met.

Description

Technical Field

[0001] The present invention relates to the field of automobile electronic control technology, and in particular to a three-phase motor safety shutdown control system and a control method thereof, which are aimed at a motor drive controller ECU and are used to realize a system protection function under a motor drive fault. Background Art

[0002] Due to their low operating noise, high reliability and long life, three-phase brushless DC motors and three-phase permanent magnet synchronous motors are widely used in automotive electronic control moving parts. Since vehicles are generally powered by DC power or batteries, the drive and application of three-phase motors require a corresponding electronic control unit ECU. On the one hand, the ECU converts the DC power supply into three-phase AC power of U, V, and W, and drives the motor to operate according to the system control requirements; on the other hand, when the ECU detects a motor function failure or abnormal operation of the control system, it is necessary to use safety shutdown control to ensure that the motor enters the expected controllable safety state, and avoid damage to the ECU drive circuit caused by overvoltage and overcurrent caused by the continued operation of the motor.

[0003] There are two common safety shutdown methods for three-phase motor drives: one is to switch the motor drive from the normal PWM control mode to the shutdown control mode, short-circuit the three-phase U, V, and W drive lines of the motor, and put the three-phase motor into a fast braking state. The other is to disable the motor drive in the event of a fault, shut down the three-phase U, V, and W drives of the motor, and stop the motor after the natural continuous current of the motor winding ends. Taking into account the differences in failure modes and impacts of different motor faults, the electronic control unit ECU needs to identify different fault states and perform targeted shutdown controls. At the same time, considering the impact of the continued fault, a shutdown latch control is also required for specific faults until the system identification state returns to normal and the shutdown control is unlocked.

[0004] At present, the main control microcontroller usually monitors the overvoltage and overcurrent faults of the driver and controls the output shutdown signal. Due to the need for program periodic sampling control, the fault cannot be effectively identified and processed in time during the interval of program periodic monitoring, increasing the risk of damage to the driver due to overvoltage and overcurrent; in addition, in the event of a failure in the operation of the main control microcontroller, the continuous validity of its output shutdown signal cannot be ensured, and the abnormal drive signal will cause the motor to malfunction and enter an unexpected operating state.

[0005] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present invention, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0006] The purpose of the present invention is to solve the technical problems existing in the background technology. To this end, a three-phase motor safety shutdown control system and a control method thereof are provided.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] A three-phase motor safety shutdown control system, comprising a motor fault monitoring unit, a system status monitoring unit, a logic control unit, a microcontroller unit, a drive unit and a three-phase motor;

[0009] The input end of the motor fault monitoring unit is connected to the three-phase motor, the first output end of the motor fault monitoring unit is connected to the logic control unit, and the second output end of the motor fault monitoring unit is connected to the first input end of the microcontroller unit;

[0010] The system status monitoring unit is used to monitor the operating status of the internal system of the ECU, a first output end of the system status monitoring unit is connected to the logic control unit, and a second output end of the system status monitoring unit is connected to a third input end of the microcontroller unit;

[0011] The microcontroller unit is connected to the logic control unit, the logic control unit is connected to the drive unit, and the drive unit is used to convert the DC power supply into a power drive output acting on the three-phase motor.

[0012] The following is a technical solution further defined by the system in the present invention, wherein the logic control unit includes a shutdown control locking module, a three-phase control signal logic processing module and a drive enable logic control module;

[0013] The first input end of the shutdown control locking module is connected to the first output end of the motor fault monitoring unit, and the second input end of the shutdown control locking module is connected to the first output end of the microcontroller unit;

[0014] The first output end of the shutdown control locking module is connected to the second input end of the three-phase control signal logic processing module, the second output end of the shutdown control locking module is connected to the second input end of the drive enable logic control module, and the third output end of the shutdown control locking module is connected to the second input end of the microcontroller unit.

[0015] The following is a technical solution further defined by the system in the present invention, wherein the first input end of the three-phase control signal logic processing module is connected to the second output end of the microcontroller unit, and the second input end of the three-phase control signal logic processing module is connected to the first output end of the shutdown control locking module;

[0016] The output end of the three-phase control signal logic processing module is connected to the first input end of the driving unit.

[0017] The following is a technical solution further defined by the system in the present invention, wherein the first input end of the driving enable logic control module is connected to the third output end of the microcontroller unit, the second input end of the driving enable logic control module is connected to the second output end of the shutdown control locking module, and the third input end of the driving enable logic control module is connected to the first output end of the system status monitoring unit;

[0018] The output end of the drive enable logic control module is connected to the second input end of the drive unit.

[0019] The following is a technical solution further defined by the system in the present invention, wherein the driving unit includes a driving chip, 6 power switch tubes and a DC power supply;

[0020] The driving chip includes a U-phase control input terminal, a V-phase control input terminal, a W-phase control input terminal, an enable control input terminal, a U-phase control output terminal, a V-phase control output terminal, and a W-phase control output terminal;

[0021] The six power switch tubes include a first power switch tube, a second power switch tube, a third power switch tube, a fourth power switch tube, a fifth power switch tube, and a sixth power switch tube, wherein the first power switch tube is connected in series with the second power switch tube and then connected to the positive and negative ends of the DC power supply, the third power switch tube is connected in series with the fourth power switch tube and then connected to the positive and negative ends of the DC power supply, and the fifth power switch tube is connected in series with the sixth power switch tube and then connected to the positive and negative ends of the DC power supply;

[0022] The U-phase control output end is connected to the first power switch tube and the second power switch tube, the V-phase control output end is connected to the third power switch tube and the fourth power switch tube, and the W-phase control output end is connected to the fifth power switch tube and the sixth power switch tube;

[0023] The line between the first power switch tube and the second power switch tube is connected to the U-phase power drive output end, the line between the third power switch tube and the fourth power switch tube is connected to the V-phase power drive output end, and the line between the fifth power switch tube and the sixth power switch tube is connected to the W-phase power drive output end;

[0024] The U-phase power drive output terminal, the V-phase power drive output terminal and the W-phase power drive output terminal are connected to the three-phase motor.

[0025] A control method based on the above three-phase motor safety shutdown control system comprises the following steps:

[0026] Step 1: The motor fault monitoring unit monitors the operating status of the three-phase motor and transmits the monitoring data to the microcontroller unit and the logic control unit;

[0027] Step 2: The system status monitoring unit monitors the operating status of the internal system of the ECU and transmits the monitoring data to the microcontroller unit and the logic control unit;

[0028] Step 3: The microcontroller unit processes the monitoring data to obtain a logic control instruction, and transmits the logic control instruction to the logic control unit;

[0029] Step 4: The logic control unit performs logic operation on the monitoring data transmitted from the motor fault monitoring unit, the monitoring data transmitted from the system status monitoring unit, and the control instruction transmitted from the microcontroller unit to obtain a drive control instruction, and transmits the drive control instruction to the drive unit;

[0030] Step 5: Based on the drive control instruction, the drive unit controls the operating state of the three-phase motor.

[0031] The following is a technical solution further defined by the method in the present invention, wherein the motor fault monitoring unit outputs a fault state feedback signal FB1 to the logic control unit, and the motor fault monitoring unit outputs a fault state feedback signal FB2 to the microcontroller unit, wherein the fault state feedback signals FB1 and FB2 each include three states: no fault, motor drive overvoltage fault, and motor drive overcurrent fault.

[0032] The following is a technical solution further defined by the method in the present invention, wherein the system status monitoring unit monitors the internal power supply status of the ECU and the program running status of the microcontroller unit; and the system status monitoring unit outputs a safety shutdown control signal S1 to the logic control unit, and the system status monitoring unit outputs a safety shutdown state feedback signal FB4 to the microcontroller unit, wherein the safety shutdown control signal S1 and the safety shutdown state feedback signal FB4 both include two states: a safety shutdown control invalid state and a safety shutdown control valid state.

[0033] The following is a technical solution further defined by the method in the present invention, wherein the logic control unit includes a shutdown control locking module, a three-phase control signal logic processing module and a drive enable logic control module;

[0034] The motor fault monitoring unit outputs a fault state feedback signal FB1 to the shutdown control locking module, and the microcontroller unit outputs a fault shutdown unlocking signal C1 to the shutdown control locking module;

[0035] The shutdown control locking module determines its output signal according to the fault state feedback signal FB1 and the fault shutdown unlocking signal C1 inputted thereto: outputs the fault shutdown control signal S2 to the three-phase control signal logic processing module, outputs the drive enable control signal S3 to the drive enable logic control module, and outputs the signal latch state feedback signal FB3 to the microcontroller unit;

[0036] The fault shutdown control signal S2 includes two states: no shutdown control and fault shutdown control; the drive enable control signal S3 includes three states: no enable control, drive enable control and locked drive disable control; the signal latch state feedback signal FB3 includes two states: non-latch state and latch state;

[0037] The microcontroller unit outputs the control end three-phase control signal C2 to the three-phase control signal logic processing module, and the three-phase control signal logic processing module determines its output signal according to the fault shutdown control signal S2 and the control end three-phase control signal C2 inputted by it: outputs the drive end three-phase control output signal C3 to the drive unit;

[0038] The microcontroller unit outputs a control terminal enable control signal C4 to the drive enable logic control module, and the system status monitoring unit outputs a safety shutdown control signal S1 to the drive enable logic control module;

[0039] The drive enable logic control module determines its output signal according to the control end enable control signal C4, the safety shutdown control signal S1 and the drive enable control signal S3 inputted thereto: outputs the drive end enable control signal C5 to the drive unit;

[0040] The driving end enabling control signal C5 includes two states: a driving enabling state and a driving disabling state.

[0041] The following is a technical solution further defined by the method in the present invention: when the fault state feedback signal FB1 is in a no-fault state and the safety shutdown control signal S1 is in a safety shutdown control invalid state, the fault shutdown control signal S2 is a no-shutdown control, the three-phase control output signal C3 of the driving end is consistent with the three-phase control signal C2 of the control end, the driving enable control signal S3 is a no-enable control, and the driving end enable control signal C5 is consistent with the control end enable control signal C4;

[0042] When the fault state feedback signal FB1 is the motor drive overvoltage fault state and the safety shutdown control signal S1 is the safety shutdown control invalid state, the fault shutdown control signal S2 is the fault shutdown control, the drive end three-phase control output signal C3 is fixed to: all high level or all low level, the drive enable control signal S3 is the drive enable control, and the drive end enable control signal C5 is fixed to the drive enable state;

[0043] When the fault state feedback signal FB1 is a motor drive overcurrent fault and the safety shutdown control signal S1 is in the safety shutdown control invalid state, the fault shutdown control signal S2 is a fault shutdown control, the drive enable control signal S3 is a locked drive disable control, and the drive end enable control signal C5 is locked in the drive disable state;

[0044] When the safety shutdown control signal S1 is in the safety shutdown control effective state, no matter what state the fault state feedback signal FB1 is in, the drive end enable control signal C5 is fixedly output as the drive disable state.

[0045] Compared with the prior art, the present invention has the following technical effects:

[0046] The present invention sets up a safety shutdown control system. First, it can obtain and distinguish fault monitoring signals such as overvoltage of the driving power supply and overcurrent of the motor; secondly, after detecting a fault, the safety shutdown control system can provide fast and synchronous U, V, W three-phase shutdown control signals and drive enable / disable control signals, which act on the three-phase motor drive control end, realize microsecond-level fault response and three-phase motor shutdown control, effectively avoid the risk of overvoltage and overcurrent of the driving circuit under fault, and meet the system requirement of quickly entering a safe state after failure; finally, for the latching and unlocking control of the safety shutdown, after a specific fault occurs, the output can be locked to maintain a safe state, and the shutdown control can be unlocked according to control needs to restore normal drive control, which not only effectively prevents electrical overstress of the driving device, but also provides an available control path for function recovery after the system fault disappears.

[0047] The present invention is further described below in conjunction with the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0049] Figure 1 is a system connection relationship diagram of the present invention;

[0050] Figure 2 It is a structural connection diagram of the drive unit in the present invention. DETAILED DESCRIPTION

[0051] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0052] like Figure 1 and 2As shown, this embodiment provides a three-phase motor safety shutdown control system, which is mainly composed of a motor fault monitoring unit, a system status monitoring unit, a logic control unit, a microcontroller unit, a drive unit and a three-phase motor.

[0053] 1. Motor fault monitoring unit

[0054] The motor fault monitoring unit is responsible for monitoring motor operation faults. The fault status feedback signal FB1 outputted by the first channel is connected to the logic control unit. The fault status feedback signal FB1 includes three states: no fault, motor drive overvoltage fault, and motor drive overcurrent / overtemperature fault. The fault status feedback signal FB2 outputted by the second channel of the motor fault monitoring unit is connected to the microcontroller unit. The fault status feedback signal FB2 also includes the three states of FB1, but is outputted to the microcontroller unit through a hardware path different from FB1. Therefore, both the microcontroller unit and the logic control unit can obtain the operating status of the three-phase motor, including: no fault, motor drive overvoltage fault, and motor drive overcurrent / overtemperature fault.

[0055] 2. System Status Monitoring Unit

[0056] The system status monitoring unit is used to monitor the operating status of the ECU internal system, including the power supply status of the ECU internal power supply and the program running status of the microcontroller unit. The first output of the safety shutdown control signal S1 is connected to the logic control unit. The safety shutdown control signal S1 includes two states: the safety shutdown control invalid state and the safety shutdown control valid state; the second output of the system status monitoring unit The safety shutdown state feedback signal FB4 is connected to the microcontroller unit. The safety shutdown state feedback signal FB4 also includes two states of the safety shutdown control signal S1, but is output to the microcontroller unit through a hardware path different from S1.

[0057] 3. Logic Control Unit

[0058] The logic control unit includes a shutdown control locking module (also known as a shutdown control locking / unlocking module), a three-phase control signal logic processing module and a drive enable logic control module.

[0059] 1) Shutdown control lock module

[0060] The shutdown control locking module is responsible for monitoring the fault status output by the motor fault monitoring unit, determining the shutdown latch control and enable control according to the fault status, and outputting them to the three-phase control signal logic processing module and the drive enable logic control module respectively, while feeding back the shutdown latch status to the microcontroller unit.

[0061] The first input of the shutdown control locking module is connected to the fault state feedback signal FB1 output by the motor fault monitoring unit, and the second input is connected to the fault shutdown unlocking signal C1 output by the microcontroller unit.

[0062] The shutdown control locking module provides three signal outputs: the first output fault shutdown control signal S2 is connected to the input of the three-phase control signal logic processing module, the second output drive enable control signal S3 is connected to the input of the drive enable logic control module, and the third output signal latch state feedback signal FB3 is connected to the input of the microcontroller unit. The fault shutdown control signal S2 includes two states: no shutdown control and fault shutdown control. The drive enable control signal S3 includes three states: no enable control, drive enable control and locked drive disable control. The signal latch state feedback signal FB3 includes two states: non-latch state and latch state.

[0063] The shutdown control locking module determines the states of its three output control signals according to the three states of the fault state feedback signal FB1 inputted to it:

[0064] When the fault state feedback signal FB1 is in a non-fault state, the fault shutdown control signal S2 is in a non-shutdown control, the drive enable control signal S3 is in a non-enable control, and the signal latch state feedback signal FB3 is in a non-latch state;

[0065] When the fault state feedback signal FB1 is in the motor drive overvoltage fault state, the fault shutdown control signal S2 is in the fault shutdown control, the drive enable control signal S3 is in the drive enable control, and the signal latch state feedback signal FB3 is in the non-latched state;

[0066] When the fault state feedback signal FB1 is a motor drive overcurrent / overtemperature fault, the fault shutdown control signal S2 is a fault shutdown control, the drive enable control signal S3 is a locked drive disable control, and the signal latch state feedback signal FB3 is a latched state.

[0067] 2) Three-phase control signal logic processing module

[0068] The three-phase control signal logic processing module is used to integrate the control end three-phase control signal C2 (also known as the control end U / V / W control signal C2) output by the microcontroller unit and the fault shutdown control signal S2 output by the shutdown control locking module, and determine the drive end three-phase control signal C3 (also known as the drive end U / V / W control signal C3) output to the drive unit according to the fault shutdown control signal S2.

[0069] The first input of the three-phase control signal logic processing module is connected to the control terminal U / V / W control signal C2 output by the microcontroller unit, and the second input is connected to the fault shutdown control signal S2 output by the shutdown control locking module.

[0070] The driving end U / V / W control output signal C3 output by the three-phase control signal logic processing module is connected to the input of the driving unit.

[0071] When the fault state feedback signal FB1 is in a no-fault state, the fault shutdown control signal S2 is in a no-shutdown control state, and the drive end U / V / W control output signal C3 output by the three-phase control signal logic processing module is consistent with the control end U / V / W control signal C2 input thereto;

[0072] When the fault state feedback signal FB1 is the motor drive overvoltage fault state, the fault shutdown control signal S2 is the fault shutdown control, and the drive end U / V / W control output signal C3 output by the three-phase control signal logic processing module is fixed to all high level or all level;

[0073] When the fault state feedback signal FB1 is a motor drive overcurrent / overtemperature fault, the fault shutdown control signal S2 is a fault shutdown control, the drive enable control signal S3 is a locked drive disable control, and the drive end enable control signal C5 is locked to a drive disable state.

[0074] 3) Drive enable logic control module

[0075] The drive enable logic control module is used to integrate the control signals output by the microcontroller unit, the shutdown control locking module and the system status monitoring unit, and determine the drive enable control output to the drive unit according to the signal status.

[0076] The first input of the drive enable logic control module is connected to the control end enable control signal C4 (also known as the control end enable / disable control signal C4) output by the microcontroller unit, the second input is connected to the drive enable control signal S3 output by the shutdown control locking module, and the third input is connected to the safety shutdown control signal S1 output by the system status monitoring unit.

[0077] The drive end enable control signal C5 (also called drive end enable / disable control signal C5) output by the drive enable logic control module is connected to the input of the drive unit. The drive end enable control signal C5 includes two states: drive enable state and drive disable state.

[0078] When the safety shutdown control signal S1 output is the safety shutdown control invalid state, when the fault state feedback signal FB1 is the no-fault state, the drive enable control signal S3 is the no-enable control, and the drive-end enable control signal C5 is consistent with the control-end enable / disable control C4 signal; when the fault state feedback signal FB1 is the motor drive overvoltage fault state, the drive enable control signal S3 is the drive enable control, and the drive-end enable control signal C5 is fixed to the drive enable state, and may be inconsistent with the control-end enable control signal C4 output by the microcontroller unit; when the fault state feedback signal FB1 is the motor drive overcurrent / overtemperature fault, the drive enable control signal S3 is the locked drive disable control, and the drive-end enable control signal C5 is locked to the drive disable state.

[0079] When the safety shutdown control signal S1 is output as the safety shutdown control effective state, no matter what state the fault state feedback signal FB1 is in, the drive end enable control signal C5 is fixedly output as the drive disable state.

[0080] 4. Microcontroller Unit

[0081] The microcontroller unit is responsible for motor function control, motor status monitoring, shutdown status monitoring and fault status management. When the system is working normally, the motor is controlled to run according to the required speed and torque; when the motor fails, the fault state is identified and the shutdown control state is turned off; after the fault is restored, the control output is switched to normal control.

[0082] The first input of the microcontroller unit is connected to the fault state feedback signal FB2 output by the motor fault monitoring unit, the second input is connected to the signal latch state feedback signal FB3 output by the shutdown control locking module, and the third input is connected to the safety shutdown state feedback signal FB4 output by the system state monitoring unit.

[0083] The fault shutdown unlock signal C1 of the first output of the microcontroller unit is connected to the input of the shutdown control locking module. The unlocking effective signal is a level change, and the output jumps from a low level to a high level to unlock the drive disable control; the control end U / V / W control signal C2 of the second output is connected to the input of the three-phase control signal logic processing module, which contains the switch control information of the 6 power switch tubes driven by the three-phase U / V / W from the MCU end; the control end enable control signal C4 of the third output is connected to the input of the drive enable logic control module.

[0084] 5. Drive unit

[0085] The drive unit is responsible for converting the DC power supply into U / V / W power drive output acting on the three-phase motor according to its U / V / W three-phase input control and drive end enable.

[0086] The first input of the driving unit is connected to the driving end U / V / W control output signal C3, and the second input is connected to the driving end enable control signal C5.

[0087] The three-phase U / V / W drive output by the drive unit is connected to the three-phase motor.

[0088] The driving end U / V / W control output signal C3 includes the switch control information of the six power switch tubes driven by the three-phase U / V / W, and the driving end enable / disable control signal C5 is the enable control of the driving end U / V / W control output signal C3; when the driving end enable / disable control signal C5 is enabled, the three-phase U / V / W power drive output of the motor is synchronized with the driving end U / V / W control output signal C3; when the driving end enable / disable control signal C5 is disabled, the three-phase U / V / W power drive output of the motor is turned off and is not affected by the driving end U / V / W control output signal C3.

[0089] When the system is working, the logic control unit performs logic operation processing on the control end U / V / W control signal C2 output by the microcontroller unit and the fault shutdown control signal S2 output by the shutdown control locking / unlocking module to obtain the drive end U / V / W control signal C3 acting on the control end of the drive unit; the logic control unit performs logic operation processing on the control end enable / disable control signal C4 output by the microcontroller unit, the safety shutdown control signal S1 and the drive enable control signal S3 to obtain the drive end enable / disable control C5 acting on the drive unit input.

[0090] In this embodiment, the logic control unit realizes the drive shutdown control under fault conditions through a combination of hardware circuits and logic gate circuits, which can achieve microsecond-level fault response and three-phase motor shutdown control, effectively avoiding the risk of overvoltage and overcurrent in the drive circuit under fault conditions, and at the same time meeting the system's requirement to quickly enter a safe state after failure. For load overcurrent faults, the logic control unit will latch the output shutdown state until the microcontroller unit issues a valid unlocking command.

[0091] The working principle of this embodiment will be further described below:

[0092] When the system is working normally, the motor fault monitoring unit does not detect the motor drive fault, and the fault state feedback signal FB1 is a no-fault state; the system state monitoring unit does not detect the system abnormal state, and the safety shutdown control signal S1 is an invalid state of the safety shutdown control; the shutdown control lock / unlock module outputs no shutdown and no enable control; the drive end U / V / W control output signal C3 output by the three-phase control signal logic processing module is consistent with the control end U / V / W control signal C2 output by the microcontroller unit; the drive end enable / disable control signal C5 output by the drive enable logic control module is consistent with the control end enable / disable control C4 output by the microcontroller unit. The microcontroller unit controls the three-phase motor drive to enable or disable according to the system function requirements. When the three-phase motor needs to run, the microcontroller unit controls the three-phase motor drive to enable, the drive unit enables the motor control, and drives the three-phase motor to run according to the control end U / V / W control signal C2 output by the microcontroller unit; when the three-phase motor needs to stop, the microcontroller unit controls the three-phase motor drive to disable, and the drive unit controls the motor to stop.

[0093] When the motor drive fails to overvoltage, the motor fault monitoring unit detects the motor drive fault, and the fault state feedback signal FB1 is the motor drive overvoltage fault state; the system state monitoring unit does not detect the internal abnormality of the ECU, and the safety shutdown control signal S1 is the safety shutdown control invalid state; the fault shutdown control signal S2 output by the shutdown control lock / unlock module is the fault shutdown control, and the drive enable control signal S3 is the drive enable control; under the control of S2, the three-phase control signal logic processing module fixes the drive end U / V / W control output signal C3 to all high level or all level; under the control of S3, the drive enable logic control module fixes the output drive end enable / disable control signal C5 to the drive enable state, and it may be inconsistent with the control end enable / disable control C4 signal output by the microcontroller unit; the drive unit controls the motor's U / V / W three phases to be short-connected to the motor's positive power supply or all short-connected to the motor's negative power supply, and the three-phase motor enters the brake rapid braking state.

[0094] Since the fault shutdown control of the fault shutdown control signal S2 has no self-locking function when the motor drive overvoltage fault occurs, when the motor drive overvoltage fault is eliminated, the fault state feedback signal FB1 is restored to a no-fault state, the fault shutdown control signal S2 is restored to no-shutdown control, the drive enable control signal S3 is restored to no-enable control, and the motor drive is restored to a normal working state controlled by the microcontroller unit.

[0095] During a fault process, the microcontroller unit can identify an overvoltage fault of the motor drive through the fault state feedback signal FB2.

[0096] When the motor drive has an overcurrent / overtemperature fault, the motor fault monitoring unit detects the motor drive fault, and the fault status feedback signal FB1 is the motor drive overcurrent / overtemperature fault status; the system status monitoring unit does not detect any abnormality inside the ECU, and the safety shutdown control signal S1 is the safety shutdown control invalid state; the fault shutdown control signal S2 output by the shutdown control lock / unlock module is the fault shutdown control, and the drive enable control signal S3 is the locked drive disable control; under the control of S3, the drive enable logic control module locks the output drive end enable / disable control signal C5 to the drive disable state, and the drive unit controls the three-phase U, V, and W drives of the motor to be shut down, and the motor winding stops after the natural freewheeling ends.

[0097] Since fault monitoring, motor fault shutdown and shutdown control latch are all implemented through hardware circuits, microsecond-level fault response and three-phase motor shutdown control can be achieved, effectively avoiding the risk of overcurrent / overtemperature failure of the drive circuit under fault conditions.

[0098] When the motor drive overcurrent / overtemperature fault is eliminated, the fault status feedback signal FB1 is restored to a fault-free state, but due to the motor drive overcurrent / overtemperature fault, the drive enable control signal S3 is a locked drive disable control. After the fault is triggered, the three-phase U, V, and W drives of the motor maintain a continuous off state to avoid continuous attempts to start under the fault and cause damage to the device.

[0099] During a fault, the microcontroller unit can identify the overcurrent / overtemperature fault of the motor drive through the fault status feedback signal FB2, and can also identify the shutdown latch state through the signal latch state feedback signal FB3. When the microcontroller unit determines that the fault has been eliminated and the system environment meets the restart conditions, it can unlock the drive disable by outputting the fault shutdown unlock signal C1 and enable the motor drive control again.

[0100] When the ECU internal system fails to operate, the motor fault monitoring unit does not detect the motor drive fault, and the fault status feedback signal FB1 is in a no-fault state; the system status monitoring unit detects an abnormality inside the ECU, and the safety shutdown control signal S1 is in a valid safety shutdown control state; the shutdown control lock / unlock module outputs no shutdown and no enable control; under the control of the safety shutdown control signal S1, the drive enable logic control module controls the output drive end enable / disable control signal C5 to a drive disable state, and the drive unit controls the three-phase U, V, and W drives of the motor to shut down, and the motor winding stops after the natural freewheeling ends.

[0101] During a fault, the microcontroller unit can obtain the safety shutdown control state through the safety shutdown state feedback signal FB4.

[0102] The above is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Any technician familiar with the art can make many possible changes and modifications to the technical solution of the present invention by using the above disclosed methods and technical contents without departing from the scope of the technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. Therefore, all equivalent changes made according to the shape, structure and principle of the present invention without departing from the content of the technical solution of the present invention should be included in the protection scope of the present invention.

Claims

1. A three-phase motor safety shutdown control system, characterized in that: It includes a motor fault monitoring unit, a system status monitoring unit, a logic control unit, a microcontroller unit, a drive unit and a three-phase motor; The input end of the motor fault monitoring unit is connected to the three-phase motor, the first output end of the motor fault monitoring unit is connected to the logic control unit, and the second output end of the motor fault monitoring unit is connected to the first input end of the microcontroller unit; The system status monitoring unit is used to monitor the operating status of the internal system of the ECU, a first output end of the system status monitoring unit is connected to the logic control unit, and a second output end of the system status monitoring unit is connected to a third input end of the microcontroller unit; The microcontroller unit is connected to the logic control unit, the logic control unit is connected to the drive unit, and the drive unit is used to convert the DC power supply into a power drive output acting on the three-phase motor.

2. A three-phase motor safety shutdown control system as claimed in claim 1, characterized in that: The logic control unit includes a shutdown control locking module, a three-phase control signal logic processing module and a drive enable logic control module; The first input end of the shutdown control locking module is connected to the first output end of the motor fault monitoring unit, and the second input end of the shutdown control locking module is connected to the first output end of the microcontroller unit; The first output end of the shutdown control locking module is connected to the second input end of the three-phase control signal logic processing module, the second output end of the shutdown control locking module is connected to the second input end of the drive enable logic control module, and the third output end of the shutdown control locking module is connected to the second input end of the microcontroller unit.

3. A three-phase motor safety shutdown control system as claimed in claim 2, characterized in that: The first input end of the three-phase control signal logic processing module is connected to the second output end of the microcontroller unit, and the second input end of the three-phase control signal logic processing module is connected to the first output end of the shutdown control locking module; The output end of the three-phase control signal logic processing module is connected to the first input end of the driving unit.

4. A three-phase motor safety shutdown control system as claimed in claim 2, characterized in that: The first input end of the driving enable logic control module is connected to the third output end of the microcontroller unit, the second input end of the driving enable logic control module is connected to the second output end of the shutdown control locking module, and the third input end of the driving enable logic control module is connected to the first output end of the system status monitoring unit; The output end of the drive enable logic control module is connected to the second input end of the drive unit.

5. A three-phase motor safety shutdown control system as claimed in claim 1, characterized in that: The driving unit includes a driving chip, 6 power switch tubes and a DC power supply; The driving chip includes a U-phase control input terminal, a V-phase control input terminal, a W-phase control input terminal, an enable control input terminal, a U-phase control output terminal, a V-phase control output terminal, and a W-phase control output terminal; The six power switch tubes include a first power switch tube, a second power switch tube, a third power switch tube, a fourth power switch tube, a fifth power switch tube, and a sixth power switch tube, wherein the first power switch tube is connected in series with the second power switch tube and then connected to the positive and negative ends of the DC power supply, the third power switch tube is connected in series with the fourth power switch tube and then connected to the positive and negative ends of the DC power supply, and the fifth power switch tube is connected in series with the sixth power switch tube and then connected to the positive and negative ends of the DC power supply; The U-phase control output end is connected to the first power switch tube and the second power switch tube, the V-phase control output end is connected to the third power switch tube and the fourth power switch tube, and the W-phase control output end is connected to the fifth power switch tube and the sixth power switch tube; The line between the first power switch tube and the second power switch tube is connected to the U-phase power drive output end, the line between the third power switch tube and the fourth power switch tube is connected to the V-phase power drive output end, and the line between the fifth power switch tube and the sixth power switch tube is connected to the W-phase power drive output end; The U-phase power drive output terminal, the V-phase power drive output terminal and the W-phase power drive output terminal are connected to the three-phase motor.

6. A control method based on the three-phase motor safety shutdown control system according to any one of claims 1 to 5, characterized in that: The following steps are involved: Step 1: The motor fault monitoring unit monitors the operating status of the three-phase motor and transmits the monitoring data to the microcontroller unit and the logic control unit; Step 2: The system status monitoring unit monitors the operating status of the internal system of the ECU and transmits the monitoring data to the microcontroller unit and the logic control unit; Step 3: The microcontroller unit processes the monitoring data to obtain a logic control instruction, and transmits the logic control instruction to the logic control unit; Step 4: The logic control unit performs logic operation on the monitoring data transmitted from the motor fault monitoring unit, the monitoring data transmitted from the system status monitoring unit, and the control instruction transmitted from the microcontroller unit to obtain a drive control instruction, and transmits the drive control instruction to the drive unit; Step 5: Based on the drive control instruction, the drive unit controls the operating state of the three-phase motor.

7. The control method according to claim 6, characterized in that: The motor fault monitoring unit outputs a fault state feedback signal FB1 to the logic control unit, and the motor fault monitoring unit outputs a fault state feedback signal FB2 to the microcontroller unit, wherein the fault state feedback signals FB1 and FB2 each include three states: no fault, motor drive overvoltage fault, and motor drive overcurrent fault.

8. The control method according to claim 6, characterized in that: The system status monitoring unit monitors the internal power supply status of the ECU and the program running status of the microcontroller unit; and the system status monitoring unit outputs a safety shutdown control signal S1 to the logic control unit, and the system status monitoring unit outputs a safety shutdown status feedback signal FB4 to the microcontroller unit, wherein the safety shutdown control signal S1 and the safety shutdown status feedback signal FB4 both include two states: a safety shutdown control invalid state and a safety shutdown control valid state.

9. The control method according to claim 6, characterized in that: The logic control unit includes a shutdown control locking module, a three-phase control signal logic processing module and a drive enable logic control module; The motor fault monitoring unit outputs a fault state feedback signal FB1 to the shutdown control locking module, and the microcontroller unit outputs a fault shutdown unlocking signal C1 to the shutdown control locking module; The shutdown control locking module determines its output signal according to the fault state feedback signal FB1 and the fault shutdown unlocking signal C1 inputted thereto: outputs the fault shutdown control signal S2 to the three-phase control signal logic processing module, outputs the drive enable control signal S3 to the drive enable logic control module, and outputs the signal latch state feedback signal FB3 to the microcontroller unit; The fault shutdown control signal S2 includes two states: no shutdown control and fault shutdown control; the drive enable control signal S3 includes three states: no enable control, drive enable control and locked drive disable control; the signal latch state feedback signal FB3 includes two states: non-latch state and latch state; The microcontroller unit outputs the control end three-phase control signal C2 to the three-phase control signal logic processing module, and the three-phase control signal logic processing module determines its output signal according to the fault shutdown control signal S2 and the control end three-phase control signal C2 inputted by it: outputs the drive end three-phase control output signal C3 to the drive unit; The microcontroller unit outputs a control terminal enable control signal C4 to the drive enable logic control module, and the system status monitoring unit outputs a safety shutdown control signal S1 to the drive enable logic control module; The drive enable logic control module determines its output signal according to the control end enable control signal C4, the safety shutdown control signal S1 and the drive enable control signal S3 inputted thereto: outputs the drive end enable control signal C5 to the drive unit; The driving end enabling control signal C5 includes two states: a driving enabling state and a driving disabling state.

10. The control method according to claim 9, characterized in that: When the fault state feedback signal FB1 is in a no-fault state and the safety shutdown control signal S1 is in a safety shutdown control invalid state, the fault shutdown control signal S2 is a no-shutdown control, the three-phase control output signal C3 of the driving end is consistent with the three-phase control signal C2 of the control end, the driving enable control signal S3 is a no-enable control, and the driving end enable control signal C5 is consistent with the control end enable control signal C4; When the fault state feedback signal FB1 is the motor drive overvoltage fault state and the safety shutdown control signal S1 is the safety shutdown control invalid state, the fault shutdown control signal S2 is the fault shutdown control, the drive end three-phase control output signal C3 is fixed to: all high level or all low level, the drive enable control signal S3 is the drive enable control, and the drive end enable control signal C5 is fixed to the drive enable state; When the fault state feedback signal FB1 is a motor drive overcurrent fault and the safety shutdown control signal S1 is in the safety shutdown control invalid state, the fault shutdown control signal S2 is a fault shutdown control, the drive enable control signal S3 is a locked drive disable control, and the drive end enable control signal C5 is locked in the drive disable state; When the safety shutdown control signal S1 is in the safety shutdown control effective state, no matter what state the fault state feedback signal FB1 is in, the drive end enable control signal C5 is fixedly output as the drive disable state.

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