Motor control method, storage medium, controller, and motor

Abstract

The present disclosure relates to a motor control method, a storage medium, a controller and a motor, wherein the motor control method comprises determining the thermal resistance of each MOS tube in the motor and the total power consumption, and the target environment temperature of a target MOS tube provided with a temperature sensor in the motor; determining the target environment temperature of each remaining MOS tube in the motor except the target MOS tube according to the target environment temperature and a preset data fitting relationship; determining the junction temperature of each MOS tube in the motor according to the target environment temperature of each MOS tube in the motor and the thermal resistance and total power consumption of each MOS tube; and controlling the operating state of the motor according to the junction temperature of each MOS tube in the motor. Through the target environment temperature of the target MOS tube and the preset data fitting relationship, the target environment temperature of each MOS tube can be accurately obtained, and then the accuracy of controlling the operating state of the motor can be improved according to the junction temperature of each MOS tube, and thus the damage of the motor can be reduced.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of control, in particular, to a motor control method, a storage medium, a controller and a motor. BACKGROUND

[0002] A brushless direct current motor (BLDC) is mainly a device for replacing mechanical brushes inside a motor to control commutation of a brushless motor. In the related art, a temperature sensor is usually arranged in the brushless direct current motor, and the running state of the motor is controlled by the temperature measured by the temperature sensor. However, when the running state of the motor is controlled by this method, the motor may be damaged. SUMMARY

[0003] The purpose of the present disclosure is to provide a motor control method, a storage medium, a controller and a motor to solve the technical problems existing in the related art.

[0004] To achieve the above purpose, the present disclosure provides a motor control method, which comprises:

[0005] determining the thermal resistance of each MOS tube in the motor and the total power consumption, and the target environmental temperature of a target MOS tube provided with a temperature sensor in the motor;

[0006] determining the target environmental temperature of each remaining MOS tube except the target MOS tube in the motor according to the target environmental temperature and a preset data fitting relationship, the preset data fitting relationship being a data fitting relationship between the environmental temperature of the target MOS tube and the environmental temperature of each remaining MOS tube;

[0007] determining the junction temperature of each MOS tube in the motor according to the target environmental temperature of each MOS tube in the motor and the thermal resistance and total power consumption of each MOS tube;

[0008] controlling the running state of the motor according to the junction temperature of each MOS tube in the motor.

[0009] Optionally, the preset data fitting relationship is obtained by the following way:

[0010] determining a plurality of first environmental temperatures of the target MOS tube when the motor is in a preset working state through the temperature sensor, the preset working state including a first running state in which the motor works in a UV phase, a second running state in which the motor works in a UW phase, and a third running state in which the motor works in a VW phase;

[0011] For each of the first ambient temperature, the second ambient temperature of each MOS tube of the motor under the preset working state is measured, and a plurality of second ambient temperatures are obtained;

[0012] The plurality of first ambient temperatures and the plurality of second ambient temperatures under the same preset working state are data fitted, and the preset data fitting relationship is obtained.

[0013] Optionally, the junction temperature of each MOS tube in the motor is determined according to the target ambient temperature of each MOS tube in the motor and the thermal resistance and total power consumption of each MOS tube.

[0014] The junction temperature of the target MOS tube is determined according to the target ambient temperature of the target MOS tube and the thermal resistance and total power consumption of the target MOS tube.

[0015] The target ambient temperature of each remaining MOS tube is filtered to obtain a filtered ambient temperature of each remaining MOS tube, and the junction temperature of each remaining MOS tube is obtained according to the filtered ambient temperature of each remaining MOS tube and the thermal resistance and total power consumption of each remaining MOS tube.

[0016] Optionally, the target ambient temperature of each remaining MOS tube is filtered to obtain a filtered ambient temperature of each remaining MOS tube.

[0017] The target ambient temperature of each remaining MOS tube is filtered by a Kalman filtering method to obtain a filtered ambient temperature of each remaining MOS tube; or

[0018] The target ambient temperature of each remaining MOS tube is filtered by a Kalman filtering method and a first-order RC low-pass filtering method to obtain a filtered ambient temperature of each remaining MOS tube.

[0019] Optionally, the junction temperature of each MOS tube in the motor is determined according to the target ambient temperature of each MOS tube in the motor and the thermal resistance and total power consumption of each MOS tube.

[0020] The thermal resistance and total power consumption of each MOS tube in the motor are multiplied to obtain a third ambient temperature of each MOS tube.

[0021] The target ambient temperature and the third ambient temperature of each MOS tube are added to obtain the junction temperature of each MOS tube in the motor.

[0022] Optionally, the running state of the motor is controlled according to the junction temperature of each MOS tube.

[0023] According to the junction temperature of each MOS tube in the motor and the preset temperature threshold, the running state of the motor is controlled, and the preset temperature threshold is the highest temperature reached by the MOS tube in the motor.

[0024] Optionally, the controlling of the running state of the motor according to the junction temperature of each MOS tube in the motor and the preset temperature threshold comprises:

[0025] When the junction temperature of any one MOS tube in the motor reaches the preset temperature threshold, the running state of the motor is controlled to be a stop running state.

[0026] Optionally, when the working state of the motor is a non-stall working state, the controlling of the running state of the motor according to the junction temperature of each MOS tube in the motor and the preset temperature threshold comprises:

[0027] When the junction temperature of each MOS tube in the motor does not reach the preset temperature threshold, the duty cycle of the motor is reduced to keep the motor in a running state.

[0028] Optionally, when the working state of the motor is a stall working state, the controlling of the running state of the motor according to the junction temperature of each MOS tube in the motor and the preset temperature threshold comprises:

[0029] Among the MOS tubes of the motor, a MOS tube with the lowest junction temperature is determined;

[0030] When the junction temperature of each MOS tube in the motor does not reach the preset temperature threshold, the MOS tube with the lowest junction temperature is controlled to enter a running state to keep the motor in a running state.

[0031] In a second aspect, the present disclosure provides a non-transitory computer readable storage medium having a computer program stored thereon, the program being executed by a processor to implement the steps of any of the methods provided in the first aspect of the present disclosure.

[0032] In a third aspect, the present disclosure provides a controller comprising:

[0033] a memory having a computer program stored thereon;

[0034] a processor configured to execute the computer program in the memory to implement the steps of any of the methods provided in the first aspect of the present disclosure.

[0035] In a fourth aspect, the present disclosure provides a motor comprising a plurality of MOS tubes and the controller provided in the third aspect of the present disclosure.

[0036] By the technical solution, the target environment temperature of the target MOS tube provided with the temperature sensor is acquired, and the target environment temperature of each remaining MOS tube in the motor is obtained according to the target environment temperature and a preset data fitting relationship. Then, the junction temperature of each MOS tube can be obtained according to the target environment temperature of each MOS tube, the thermal resistance of each MOS tube and the total power consumption, and the running state of the motor is controlled according to the junction temperature of each MOS tube. The preset data fitting relationship is a data fitting relationship between the environment temperature of the target MOS tube and the environment temperature of each remaining MOS tube. The target environment temperature of each MOS tube can be accurately obtained through the target environment temperature of the target MOS tube and the preset data fitting relationship, and the accuracy of determining the junction temperature of each MOS tube can be improved. The accuracy of controlling the running state of the motor can be improved according to the junction temperature of each MOS tube, and the motor damage can be reduced.

[0037] Other features and advantages of the present disclosure will be described in detail in the following detailed description section. BRIEF DESCRIPTION OF DRAWINGS

[0038] The accompanying drawings are included to provide a further understanding of the present disclosure and constitute a part of the specification, and are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation on the present disclosure. In the drawings:

[0039] Figure 1 is a schematic diagram of an IGBT module circuit structure of a high-power brushless DC motor in the related art.

[0040] Figure 2 is a schematic diagram of a MOS tube circuit setting of a small and medium power brushless DC motor in the related art.

[0041] Figure 3 is a schematic diagram of a motor control method according to an exemplary embodiment of the present disclosure.

[0042] Figure 4 is a flowchart of MOS tube junction temperature calculation according to an exemplary embodiment of the present disclosure.

[0043] Figure 5 is a schematic diagram of adjusting the motor working duty cycle by the MOS tube junction temperature according to an exemplary embodiment of the present disclosure.

[0044] Figure 6 is a block diagram of an electronic device according to an exemplary embodiment. DETAILED DESCRIPTION

[0045] The detailed description of the present disclosure is described in detail below in combination with the drawings. It should be understood that the detailed description described herein is only used to illustrate and explain the present disclosure, and is not used to limit the present disclosure.

[0046] The core electronic components for motor control can be electronic components that carry a certain current. Typically, in high-power brushless DC motors (such as permanent magnet synchronous motor drivers in electric vehicles), the core component is an IGBT (Insulated Gate Bipolar Transistor) module; in low-power brushless DC motors, the core component is a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor). When a certain current flows through the IGBT module or MOSFET, significant heat is generated in each overcurrent unit of the IGBT module and on the MOSFET.

[0047] For high-power brushless DC motors, such as Figure 1 As shown, the IGBT module 3 includes multiple current-carrying units 1, each with a length of 15cm. An NTC (Negative Temperature Coefficient) sampling resistor 2 is placed next to each current-carrying unit 1 to monitor the temperature of each current-carrying unit 1 in real time. Typically, multiple NTC sampling resistors 2 are used in an IGBT module 3 to measure the temperature of different current-carrying units 1.

[0048] For small to medium power brushless DC motors, such as Figure 2 As shown, the brushless DC motor includes a first MOSFET 12 to a sixth MOSFET 7. The first MOSFET 12 and the second MOSFET 14 are combined in one column, the third MOSFET 8 and the fourth MOSFET 10 are combined in another column, and the fifth MOSFET 5 and the sixth MOSFET 7 are combined in a third column, for a total of three columns. The U phase 13 of the motor's three-phase connector is located between the first MOSFET 12 and the second MOSFET 14, the V phase 9 is located between the third MOSFET 8 and the fourth MOSFET 10, and the W phase 6 is located between the fifth MOSFET 5 and the sixth MOSFET 7. Three half-bridge circuits are constructed using the first MOSFET 12 to the sixth MOSFET 7, where the first MOSFET 12, the third MOSFET 8, and the fifth MOSFET 5 form the upper bridge arm, and the second MOSFET 14, the fourth MOSFET 10, and the sixth MOSFET 7 form the lower bridge arm. When the brushless DC motor is running, the conduction sequence of the first MOSFET 12 to the sixth MOSFET 7 can be used to control the brushless DC motor to run in the desired direction and speed. Typically, the NTC sampling resistor 2 is placed next to the combination of two MOSFETs in the second column, and the ambient temperature of each MOSFET is measured through this NTC sampling resistor 2.

[0049] For small and medium power brushless DC motor, due to the setting position of U phase 13, V phase 9 and W phase 6 in three-phase pin, the placement position of the first MOS tube 12 to the sixth MOS tube 7 may be irregular, which leads to the placement position of the NTC sampling resistor 2 being irregular, and the environmental temperature of the MOS tube at other positions cannot be measured in time. When the motor is controlled to run through the square wave control algorithm, if the NTC sampling resistor 2 is placed beside any MOS tube, and when the motor appears to be in a locked-rotor condition, it will cause the same group of MOS tubes in the motor to run for a long time. When the NTC sampling resistor 2 is placed far away from the MOS tube that enters the long-time working state, the environmental temperature of the MOS tube that enters the long-time working state cannot be obtained through measurement, which will cause errors in measuring the environmental temperature of the MOS tube at this time, and further cause the MOS tube to be burned out. If the method of setting the NTC sampling resistor 2 in the IGBT module is referred to, setting the corresponding number of NTC resistors in the small and medium power brushless DC motor may make the circuit board 4 more complex, the cost higher, and the AD (Analog to Digital) resource demand in the microcontroller unit higher.

[0050] As shown in Figure 2 According to the principle of the square wave control algorithm, it can be obtained that the brushless DC motor can only turn on two MOS tubes to enter the working state at the same time, and one MOS tube is the MOS tube of the upper bridge arm, and the other MOS tube is the MOS tube of the lower bridge arm. For example, the first MOS tube 12 and the fourth MOS tube 10 or the sixth MOS tube 7, the third MOS tube 8 and the second MOS tube 14 or the sixth MOS tube 7, and the fifth MOS tube 5 and the second MOS tube 14 or the fourth MOS tube 10. The working MOS tube is usually modulated by PWM (Pulse Width Modulation), and at the same time, the two MOS tubes entering the working state are complementarily modulated, and then the freewheeling MOS tube is turned on, so as to reduce the heat generation of the brushless DC motor. Since the on-resistance of the MOS tube is small, the on-voltage drop of the body diode is very large, and thus the freewheeling loss of the lower bridge arm MOS tube can be reduced. In the switching power consumption and on-resistance of the MOS tube, the freewheeling loss of the lower bridge arm MOS tube accounts for more than 80% of the heat generation. Therefore, reducing the freewheeling loss of the lower bridge arm MOS tube can reduce the temperature rise of the lower bridge arm MOS tube.

[0051] However, when using this method to lower the ambient temperature of the MOSFET, a situation may arise where the NTC sampling resistor 2 is placed next to phase 6 (W) between the fifth MOSFET 5 and the sixth MOSFET 7, but the conducting MOSFETs are the first MOSFET 12 and the fourth MOSFET 10. In this case, due to the poor heat transfer effect of the circuit board 4, the ambient temperature of the MOSFET sampled by the NTC sampling resistor 2 may be inaccurate. The difference between the sampled ambient temperature and the actual temperature generated by the MOSFET may even exceed the preset temperature. If the junction temperature of the MOSFET calculated from the sampled ambient temperature exceeds the maximum operating temperature threshold of the MOSFET, it may damage the MOSFET. In severe cases, it may even damage the motor.

[0052] Typically, an NTC sampling resistor 2 is set in a brushless DC motor. However, this method is usually used in scenarios with three-phase uniform overcurrent or where the brushless DC motor does not need to maintain high torque for a certain period of time. But when the brushless DC motor's shift controller enters the working state, a constant force is required to maintain the position as it approaches that gear. At this time, the brushless DC motor may stall. This constant force needs to be maintained for a certain period of time to ensure the shifting system is reliable before the operating current of the brushless DC motor can be cut off.

[0053] When the brushless DC motor stalls, two MOSFETs in the motor will remain active for an extended period, while the remaining three MOSFETs will remain inactive. The lower-arm MOSFET will be in a complementary state to the upper-arm MOSFET. This can cause severe overheating in area 4 of the circuit board corresponding to the MOSFET experiencing overcurrent, while the area corresponding to the MOSFET without overcurrent may not overheat. In some cases, the difference between the highest temperature of the MOSFET experiencing overcurrent and the lowest temperature of the MOSFET without overcurrent may exceed 30°C, potentially damaging the MOSFET and, in severe cases, damaging the motor.

[0054] In view of this, the present disclosure provides a motor control method, a storage medium, a controller, and a motor to solve the problems existing in the aforementioned related technologies.

[0055] like Figure 3 As shown, Figure 3 This is a schematic diagram illustrating a motor control method according to an exemplary embodiment of the present disclosure, with reference to... Figure 3 ,include:

[0056] S301: Determine the thermal resistance and total power consumption of each MOSFET in the motor, and the target ambient temperature of the target MOSFET in the motor equipped with a temperature sensor;

[0057] S302: determining a target ambient temperature of each remaining MOS tube in the motor except the target MOS tube according to the target ambient temperature of the target MOS tube and a preset data fitting relationship, the preset data fitting relationship being a data fitting relationship between the ambient temperature of the target MOS tube and the ambient temperature of each remaining MOS tube;

[0058] S303: determining a junction temperature of each MOS tube in the motor according to the target ambient temperature of each MOS tube in the motor and the thermal resistance and total power consumption of each MOS tube;

[0059] By the above technical solution, the target ambient temperature of the target MOS tube provided with a temperature sensor is obtained, and the target ambient temperature of each remaining MOS tube in the motor is obtained according to the target ambient temperature and a preset data fitting relationship. Then, the junction temperature of each MOS tube can be obtained according to the target ambient temperature of each MOS tube, the thermal resistance and total power consumption of each MOS tube, and the running state of the motor can be controlled according to the junction temperature of each MOS tube. The preset data fitting relationship is a data fitting relationship between the ambient temperature of the target MOS tube and the ambient temperature of each remaining MOS tube. The target ambient temperature of each MOS tube can be accurately obtained through the target ambient temperature of the target MOS tube and the preset data fitting relationship, and the accuracy of determining the junction temperature of each MOS tube can be improved. The accuracy of controlling the running state of the motor can be improved according to the junction temperature of each MOS tube, and the damage of the MOS tube and the motor can be reduced.

[0060] In order to enable those skilled in the art to better understand the motor control method provided by the present disclosure, the above steps are described in detail as follows.

[0061] For example, the thermal resistance of the MOS tube can be used to represent the heat conduction capacity of the MOS tube during operation, which can be the ratio of the temperature difference between the two ends of the heat conduction and the heat conduction power. The total power consumption of the MOS tube can include switching power consumption and conduction power consumption, wherein the switching power consumption can be the energy loss caused by the conduction and cutoff of the MOS tube during the switching process of the MOS tube. The conduction power consumption can be the energy loss caused by the conduction resistance when the MOS tube is in the conduction state.

[0062] In the present disclosure, the target MOS tube can be a MOS tube provided with a temperature sensor, and the temperature sensor can be an NTC sampling resistor 2. When the motor enters the running state, the thermal resistance and total power consumption of each MOS tube can be determined, and the voltage value of the target MOS tube can be measured by the temperature sensor. The target ambient temperature of the target MOS tube can be calculated according to the voltage value.

[0063] The target environment temperature can be applied to match the target environment temperature of each remaining MOS tube, and the target environment temperature of each MOS tube can be accurately obtained through calculation, thereby improving the accuracy of calculating the junction temperature of each MOS tube.

[0064] For example, the target environment temperature of each remaining MOS tube in the motor except the target MOS tube can be obtained according to the target environment temperature and a preset data fitting relationship. The preset data fitting relationship can be obtained by testing each MOS tube in the motor through a data test method, and can be a data fitting relationship between the environment temperature of the target MOS tube and the environment temperature of each remaining MOS tube.

[0065] For example, when the target MOS tube is the first MOS tube 12, and each remaining MOS tube is the second MOS tube 14 to the sixth MOS tube 7, the temperature of the second MOS tube 14 can be 10°, the temperature of the third MOS tube 8 can be 20°, the temperature of the fourth MOS tube 10 can be 10°, the temperature of the fifth MOS tube 5 can be 5°, and the temperature of the sixth MOS tube 7 can be 5° when the environment temperature of the first MOS tube 12 is 20°, according to the data test. The temperature of the second MOS tube 14 can be 20°, the temperature of the third MOS tube 8 can be 40°, the temperature of the fourth MOS tube 10 can be 20°, the temperature of the fifth MOS tube 5 can be 10°, and the temperature of the sixth MOS tube 7 can be 10° when the environment temperature of the first MOS tube 12 is 40°. Thus, the ratio between the environment temperature of the first MOS tube 12 and the environment temperature of the second MOS tube 14 can be obtained through the data fitting relationship: 2:1. The ratio between the environment temperature of the first MOS tube 12 and the environment temperature of the third MOS tube 8 can be 1:1. The ratio between the environment temperature of the first MOS tube 12 and the environment temperature of the fourth MOS tube 10 can be 2:1. The ratio between the environment temperature of the first MOS tube 12 and the environment temperature of the fifth MOS tube 5 can be 4:1. The ratio between the environment temperature of the first MOS tube 12 and the environment temperature of the sixth MOS tube 7 can be 4:1. Thus, when the target environment temperature is 80°, the temperature of the second MOS tube 14 can be 40°, the temperature of the third MOS tube 8 can be 80°, the temperature of the fourth MOS tube 10 can be 40°, the temperature of the fifth MOS tube 5 can be 20°, and the temperature of the sixth MOS tube 7 can be 20°.

[0066] The target environment temperature of each remaining MOS tube can be obtained through the target environment temperature and the preset data fitting relationship, thereby improving the accuracy of determining the target environment temperature of each MOS tube. The target environment temperature of each MOS tube can be applied to calculate the junction temperature of each MOS tube, thereby improving the accuracy of controlling the running state of the motor.

[0067] In one possible manner, the preset data fitting relationship is obtained as follows:

[0068] The temperature sensor determines multiple first ambient temperatures of the target MOS transistor when the motor is in a preset operating state. The preset operating state includes a first operating state in which the motor operates in UV phase 9, a second operating state in which the motor operates in UW phase 6, and a third operating state in which the motor operates in VW phase 6.

[0069] For each of the first ambient temperatures, the second ambient temperature of each remaining MOSFET of the motor under the preset operating state is measured to obtain multiple second ambient temperatures;

[0070] The preset data fitting relationship is obtained by fitting the data of the plurality of first ambient temperatures and the plurality of second ambient temperatures under the same preset working state.

[0071] It should be understood that when a preset data fitting relationship is obtained through data experimentation on the motor, a temperature probe can be installed on each MOSFET from the second MOSFET 14 to the sixth MOSFET 7. Under the same preset operating condition, the first ambient temperature of the first MOSFET 12 is measured by a temperature sensor, and the second ambient temperature of the corresponding MOSFET is measured by a temperature probe. The measured multiple first ambient temperatures and corresponding multiple second ambient temperatures are then processed according to the data fitting relationship to obtain a fitting curve. This fitting curve is used as the preset data fitting relationship, which can then be applied to the process of controlling the motor's operating state. The preset operating state can include both the operating state when the motor is not stalled and the operating state when the motor is stalled.

[0072] like Figure 2 As shown, when the motor stalls, the preset operating states can include a first operating state in which the motor operates in phase 9 of UV phase, a second operating state in which the motor operates in phase 6 of UW phase, and a third operating state in which the motor operates in phase 6 of VW phase.

[0073] In determining the preset data fitting relationship, this disclosure uses the first operating state as an example. When testing the motor, the first MOSFET 12 can be used as the target MOSFET, and the second MOSFET 14 to the sixth MOSFET 7 can be used as each of the remaining MOSFETs. When the motor is operating in the first operating state, it can be determined that the motor has stalled. According to the principle of the square wave control algorithm, it can be determined that the stalled MOSFETs in the motor can be the first MOSFET 12 and the fourth MOSFET 10, or the third MOSFET 8 and the second MOSFET 14.

[0074] Taking the first MOS tube 12 and the fourth MOS tube 10 as an example, when the motor is stalled, the first MOS tube 12 and the fourth MOS tube 10 enter the working state for a long time, and a large amount of heat is generated on the first MOS tube 12 and the second MOS tube 14. At this time, the temperature sensor can measure a plurality of first environmental temperatures of the first MOS tube 12, and when each first environmental temperature is measured, the temperature detector can measure a plurality of second environmental temperatures of each remaining MOS tube, so that a plurality of second environmental temperatures of each remaining MOS tube can be obtained when a plurality of first environmental temperatures are measured. Then, the plurality of first environmental temperatures and the plurality of second environmental temperatures of each remaining MOS tube can be data-fitted by data fitting, to obtain a first sub-preset data fitting relationship. When the stalled MOS tube is the second MOS tube 14 and the third MOS tube 8, the second sub-preset data fitting relationship can be obtained by the same test calculation method.

[0075] When the motor is in the second running working state and the third running working state, the test calculation method is the same as the test method of the motor in the first running working state, which is not described here, and the third sub-preset data fitting relationship to the sixth sub-preset data fitting relationship are obtained by the test method.

[0076] When the motor is not stalled, according to the principle of the square wave control algorithm, the environmental temperature of each MOS tube in the motor is the same. Therefore, a plurality of first environmental temperatures of the first MOS tube 12 can be measured by the temperature sensor, and for each first environmental temperature, a plurality of second environmental temperatures of each remaining MOS tube can be measured by the temperature detector, and then the plurality of first environmental temperatures and the plurality of second environmental temperatures corresponding to each remaining MOS tube can be processed by data fitting to obtain a seventh sub-preset data fitting relationship.

[0077] Therefore, the first sub-preset data fitting relationship to the seventh sub-preset data fitting relationship can be combined into a preset data fitting relationship.

[0078] By the data test method, the first MOS tube 12 to the sixth MOS tube 7 are tested under different working states of the motor, and the plurality of first environmental temperatures and the plurality of second environmental temperatures corresponding to each remaining MOS tube are processed by data fitting to obtain a preset data fitting relationship, which can be applied to determine the target environmental temperature of each remaining MOS tube, thereby improving the accuracy of determining the target environmental temperature of each MOS tube.

[0079] For example, the junction temperature of the MOS tube can be the junction temperature of the internal chip of the MOS tube. After determining the target ambient temperature of each MOS tube, for each MOS tube, the junction temperature can be determined according to the thermal resistance, the total power consumption and the target ambient temperature. The junction temperature can be obtained by multiplying the thermal resistance by the total power consumption and then adding the target ambient temperature.

[0080] In a possible manner, the junction temperature of each MOS tube in the motor is determined according to the target ambient temperature of each MOS tube in the motor and the thermal resistance and the total power consumption of each MOS tube, comprising:

[0081] The thermal resistance and the total power consumption of each MOS tube in the motor are multiplied to obtain a third ambient temperature of each MOS tube.

[0082] The target ambient temperature and the third ambient temperature of each MOS tube are added to obtain the junction temperature of each MOS tube in the motor.

[0083] It should be understood that the total power consumption of the MOS tube can be obtained by adding the switching power consumption and the conduction power consumption. The conduction power consumption can be obtained by multiplying the conduction resistance of the MOS tube by the phase current, wherein the conduction resistance of the MOS tube can be the resistance generated when the current passes through the MOS tube in the on state, and the phase current of the MOS tube can be the current passing between the gate and the source during the operation of the MOS tube.

[0084] The switching loss can be obtained by dividing the sum of the rise time and the fall time, the bus voltage, the phase current path and the switching frequency by 2. The rise time of the MOS tube can be the time from the on state to the off state in the switching process of the MOS tube. The fall time of the MOS tube can be the time from the off state to the on state in the switching process of the MOS tube. The bus voltage of the MOS tube can be the voltage between the drain and the source of the MOS tube. The switching frequency of the MOS tube can be the maximum supportable frequency in the switching process from the on state to the off state or from the off state to the on state.

[0085] Then for each MOS tube, the third ambient temperature of the MOS tube can be obtained by multiplying the thermal resistance and the total power consumption of the MOS tube, which can be the temperature rise of the air in the vicinity caused by the MOS tube dissipating heat to the air, and the temperature rise of the air can cause the temperature of other MOS tubes to rise and thus cause the temperature difference. The third ambient temperature and the target ambient temperature of each MOS tube are added to obtain the junction temperature of each MOS tube.

[0086] According to the target ambient temperature, the thermal resistance and the total power consumption of each MOS tube, the junction temperature of each MOS tube can be obtained, which can improve the accuracy of controlling the operating state of the motor.

[0087] In a possible manner, the junction temperature of each MOS tube in the motor is determined according to the target ambient temperature of each MOS tube in the motor and the thermal resistance and total power consumption of each MOS tube, and the method comprises:

[0088] The junction temperature of the target MOS tube is determined according to the target ambient temperature of the target MOS tube and the thermal resistance and total power consumption of the target MOS tube.

[0089] The target ambient temperature of each remaining MOS tube is filtered to obtain a filtered ambient temperature of each remaining MOS tube, and the junction temperature of each remaining MOS tube is obtained according to the filtered ambient temperature of each remaining MOS tube and the thermal resistance and total power consumption of each remaining MOS tube.

[0090] It should be understood that when the junction temperature of the target MOS tube is determined, the target ambient temperature of the target MOS tube can be directly measured by the temperature sensor. Thus, the junction temperature of the target MOS tube can be obtained by directly adding the target ambient temperature of the target MOS tube and the product of the thermal resistance and total power consumption of the target MOS tube.

[0091] When the target ambient temperature of each remaining MOS tube is obtained according to the preset data fitting relationship and the target ambient temperature, temperature jitter may occur in the obtained target ambient temperature of each remaining MOS tube. For example, the calculated target ambient temperature of the second MOS tube 14 is 55o at the first second, becomes 53o at the third second, and becomes 60o at the fifth second. When temperature jitter occurs, the target ambient temperature of each remaining MOS tube can be filtered to obtain a filtered ambient temperature of each remaining MOS tube.

[0092] The thermal resistance of each remaining MOS tube can be multiplied by the total power consumption, and the junction temperature of each remaining MOS tube can be obtained by adding the thermal resistance multiplied by the total power consumption and the target ambient temperature. Thus, the error caused by temperature jitter can be eliminated, and the calculated junction temperature of each remaining MOS tube can be more accurate.

[0093] In a possible manner, the filtering of the target ambient temperature of each remaining MOS tube to obtain the filtered ambient temperature of each remaining MOS tube comprises:

[0094] The target ambient temperature of each remaining MOS tube is filtered by a Kalman filtering method to obtain the filtered ambient temperature of each remaining MOS tube; or

[0095] The target ambient temperature of each remaining MOS tube is filtered by a Kalman filtering method and a first-order RC low-pass filtering method to obtain the filtered ambient temperature of each remaining MOS tube.

[0096] It should be understood that when filtering the target ambient temperature of each MOS tube, the target ambient temperature of each MOS tube can be processed by a Kalman filtering method, or the target ambient temperature of each MOS tube can be processed by a Kalman filtering method and a first-order RC low-pass filtering method, and the present embodiment does not limit this.

[0097] The Kalman filtering method can be an optimal estimation method based on a state space model, and can be used to estimate the state of a linear dynamic system. The first-order RC low-pass filtering method can be a filtering method that filters out high-frequency signals and only retains low-frequency signals.

[0098] By filtering the target ambient temperature of each remaining MOS tube, the accuracy of calculating the junction temperature of each MOS tube can be improved, thereby improving the accuracy of controlling the operating state of the motor, and reducing the damage to the motor.

[0099] In practical applications, with reference to Figure 4 , Figure 4 is a flowchart of a MOS tube junction temperature calculation according to an example embodiment of the present disclosure. The MOS tube junction temperature calculation method comprises the following steps.

[0100] S401: Start.

[0101] S402: Determine the voltage value of the NTC, the thermal resistance of each MOS tube, and the total power consumption.

[0102] S403: Determine the target ambient temperature of the target MOS tube according to the voltage value of the NTC.

[0103] S404: Obtain the target ambient temperature of each remaining MOS tube according to the target ambient temperature and the preset data fitting relationship.

[0104] S405: Kalman filtering or Kalman filtering and first-order RC low-pass propagation processing are performed on the target ambient temperature of each MOS tube.

[0105] S406: Calculate the junction temperature of each MOS tube.

[0106] S407: End.

[0107] The specific implementation of each step has been described in detail above, and will not be repeated here. In addition, it should be understood that, for the above method embodiments, in order to simply describe, they are all expressed as a combination of a series of actions, but those skilled in the art should know that the disclosure is not limited by the order of the actions described above. Secondly, those skilled in the art should know that the above-described embodiments are preferred embodiments, and the steps involved are not necessarily required by the disclosure.

[0108] By processing the target environment temperature of each remaining MOS tube through the filtering processing method, the accuracy of calculating the junction temperature of each MOS tube can be improved, and the accuracy of controlling the running state of the motor can be improved, and the damage of the motor can be reduced.

[0109] For example, after determining the junction temperature of each MOS tube, the running state of the motor can be controlled according to the junction temperature of each MOS tube. During the control of the running state of the motor according to the junction temperature of each MOS tube, the running state of the motor can be controlled by comparing the junction temperature of each MOS tube with the preset temperature threshold, and the disclosure embodiments are not limited in this regard. The preset temperature threshold can be the maximum temperature value that the motor can reach.

[0110] According to the junction temperature of each MOS tube, the running state of the motor can be controlled, which can improve the accuracy of controlling the running state of the motor, and can reduce the damage of the motor, and can improve the running life of each MOS tube.

[0111] In a possible manner, the control of the running state of the motor according to the junction temperature of each MOS tube includes:

[0112] According to the junction temperature of each MOS tube in the motor and a preset temperature threshold, the running state of the motor is controlled, and the preset temperature threshold is the highest temperature reached by the MOS tube in the motor.

[0113] It should be understood that in different working states of the motor, the method of controlling the running state of the motor according to the preset temperature threshold and the junction temperature of each MOS tube is different. During the control of the running state of the motor, the motor can be divided into different working states for work, wherein the working state of the motor includes the state of occurrence of stall and the state of non-occurrence of stall.

[0114] In a possible manner, the control of the running state of the motor according to the junction temperature of each MOS tube in the motor and a preset temperature threshold includes:

[0115] When the junction temperature of any one MOS tube in the motor reaches the preset temperature threshold, the running state of the motor is controlled to be a stop running state.

[0116] It should be understood that when the working state of the motor is the working state of stalling or the working state of not stalling, if the junction temperature of any one MOS tube in the motor reaches the preset temperature threshold, it means that the temperature of the motor has reached the highest temperature that can be tolerated, and if it continues to run, the MOS tube may be burned out, thereby damaging the motor. At this time, the running state of the motor can be controlled to be a stop running state, and an over-temperature alarm can be issued to remind the relevant personnel that the motor has an over-temperature condition. So that the relevant operating personnel can take relevant measures to cool down each MOS tube in the motor, thereby ensuring that the motor is not damaged.

[0117] In a possible manner, when the working state of the motor is the non-stalling working state, the control of the running state of the motor according to the junction temperature of each MOS tube in the motor and the preset temperature threshold comprises:

[0118] When the junction temperature of each MOS tube in the motor does not reach the preset temperature threshold, the duty cycle of the motor is reduced to keep the motor in a running state.

[0119] It should be understood that when the motor does not stall, the junction temperature of each MOS tube in the motor is the same due to the running state of the motor controlled by the square wave control algorithm. Therefore, when the junction temperature of each MOS tube in the motor does not reach the preset temperature threshold, the junction temperature of each MOS tube can be adjusted by a PI (proportional-integral) adjustment method, thereby reducing the duty cycle of the motor and the junction temperature of each MOS tube, and thereby protecting the normal running state of the motor.

[0120] In actual application, referring to Figure 5 , Figure 5 is a schematic diagram of adjusting the duty cycle of a motor by the junction temperature of a MOS tube according to an exemplary embodiment of the present disclosure. The method for adjusting the duty cycle of the motor comprises the following steps.

[0121] S501: Start.

[0122] S502: Set a preset temperature threshold.

[0123] S503: Determine whether the junction temperature of each MOS tube reaches the preset temperature threshold, and when the junction temperature of each MOS tube does not reach the preset temperature threshold, execute step 504, otherwise execute step S505.

[0124] S504: Reduce the duty cycle of the motor.

[0125] S505: End.

[0126] The specific implementation of each step has been described in detail above, and will not be repeated here. In addition, it should be understood that, for the above method embodiments, in order to simply describe, they are all expressed as a series of action combinations, but those skilled in the art should know that the disclosure is not limited by the action sequence described above. Secondly, those skilled in the art should know that the above described embodiments are preferred embodiments, and the steps involved are not necessarily required by the disclosure.

[0127] In a possible manner, when the operating state of the motor is the locked-rotor operating state, the controlling the operating state of the motor according to the junction temperature of each MOS tube in the motor and the preset temperature threshold value comprises:

[0128] Among the MOS tubes of the motor, a MOS tube with the lowest junction temperature is determined;

[0129] When the junction temperature of each MOS tube in the motor does not reach the preset temperature threshold value, the MOS tube with the lowest junction temperature is controlled to enter the operating state, so that the motor remains in the operating state.

[0130] It should be understood that the MOS tube with the lowest junction temperature can be two MOS tubes, and the embodiments of the disclosure are not limited thereto.

[0131] When the motor is locked, according to the square wave control algorithm, the MOS tube entering long-time work can be determined, and then according to the target environmental temperature of the target MOS tube and the preset data fitting relationship, the target environmental temperature of each remaining MOS tube can be obtained. Then, according to the target environmental temperature of each MOS tube, the thermal resistance of each MOS tube and the total power consumption, the junction temperature of each MOS tube can be obtained. By comparing the junction temperature of each MOS tube, the junction temperature of the MOS tube entering long-time work can be obtained. At this time, the two conducting MOS tubes can be switched to the next group of MOS tubes with low temperature values to enter the operating state, so as to ensure that the motor remains in the normal operating state.

[0132] When the motor is in the state of locked-rotor, the MOS tubes entering the long-time working state are determined as the first MOS tube 12 and the fourth MOS tube 10, and the preset data fitting relationship is determined as the first sub preset data fitting relationship according to the first MOS tube 12 and the fourth MOS tube 10. The target environment temperature of the first MOS tube 12 is measured by the temperature sensor, and the target environment temperature of each remaining MOS tube can be obtained according to the target environment temperature and the first sub preset data fitting relationship. Then, the junction temperature of each MOS tube can be obtained according to the target environment temperature of each MOS tube, the thermal resistance of each MOS tube and the total power consumption. For example, when the preset temperature threshold is 90°, the junction temperature of the first MOS tube 12 is calculated as 80°, the junction temperature of the second MOS tube 14 is 40°, the junction temperature of the third MOS tube 8 is 80°, the junction temperature of the fourth MOS tube 10 is 40°, the junction temperature of the fifth MOS tube 5 is 10°, and the junction temperature of the sixth MOS tube 7 is 20°.

[0133] At this time, the junction temperature of the fifth MOS tube 5 and the junction temperature of the second MOS tube 14 can be the MOS tubes with the lowest junction temperature, and the fifth MOS tube 5 and the second MOS tube 14 can be controlled to enter the working state to maintain the normal operation of the motor. If the sum of the junction temperature of the first MOS tube 12 and the junction temperature of the fourth MOS tube 10 reaches the preset condition after the fifth MOS tube 5 and the second MOS tube 14 enter the working state for a period of time, the MOS tubes entering the working state can be switched to the first MOS tube 12 and the fourth MOS tube 10, and the preset condition can be the temperature threshold condition that needs to be reached when the first MOS tube 12 and the fourth MOS tube 10 enter the normal working state. During the whole switching process, an alarm signal can be generated and sent out to prompt the relevant operating personnel to stop the current operation state of the motor as soon as possible.

[0134] Based on the same concept, the disclosure also provides a non-transitory computer readable storage medium having a computer program stored thereon, which is executed by a processor to implement the steps of the motor control method provided by the disclosure.

[0135] Based on the same concept, the disclosure also provides a controller, comprising:

[0136] a memory having a computer program stored thereon;

[0137] a processor configured to execute the computer program in the memory to implement the steps of the motor control method provided by the disclosure.

[0138] Based on the same concept, the disclosure also provides a motor comprising a plurality of MOS tubes and the controller provided by the embodiments of the disclosure.

[0139] Figure 6is a block diagram of an electronic device 600 according to an exemplary embodiment. As shown, the electronic device 600 can include a processor 601, a memory 602. The electronic device 600 can also include one or more of a multimedia component 603, an input / output (I / O) interface 604, and a communication component 605. Figure 6

[0140] ​The processor 601 is configured to control overall operations of the electronic device 600 to complete all or part of the steps of the motor control method described above. The memory 602 is configured to store various types of data to support operations of the electronic device 600, which can include, for example, instructions for operating any application or method on the electronic device 600, and application-related data, such as contact data, sent and received messages, pictures, audio, video, and the like. The memory 602 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as a static random access memory (SRAM), an electrically erasable programmable read-only memory (EEPROM), an erasable programmable read-only memory (EPROM), a programmable read-only memory (PROM), a read-only memory (ROM), a magnetic memory, a flash memory, a magnetic disk, or an optical disk. The multimedia component 603 can include a screen and an audio component. The screen can be, for example, a touch screen, and the audio component is configured to output and / or input audio signals. For example, the audio component can include a microphone configured to receive external audio signals. The received audio signals can be further stored in the memory 602 or transmitted through the communication component 605. The audio component also includes at least one speaker configured to output audio signals. The I / O interface 604 provides an interface between the processor 601 and other interface modules, which can be a keyboard, a mouse, a button, and the like. The buttons can be virtual buttons or physical buttons. The communication component 605 is configured to perform wired or wireless communication between the electronic device 600 and other devices. The wireless communication, such as Wi-Fi, Bluetooth, near field communication (NFC), 2G, 3G, 4G, NB-IOT, eMTC, or other 5G, and the like, or a combination of one or more of them, is not limited herein. Therefore, the communication component 605 can include, for example, a Wi-Fi module, a Bluetooth module, an NFC module, and the like.

[0141] In an exemplary embodiment, the electronic device 600 can be implemented by one or more Application Specific Integrated Circuit (ASIC), Digital Signal Processor (DSP), Digital Signal Processing Device (DSPD), Programmable Logic Device (PLD), Field Programmable Gate Array (FPGA), controller, microcontroller, microprocessor or other electronic elements for executing the motor control method described above.

[0142] In another exemplary embodiment, a computer readable storage medium including program instructions is also provided, which, when executed by a processor, implement the steps of the motor control method described above. For example, the computer readable storage medium can be the memory 602 described above including program instructions, which can be executed by the processor 601 of the electronic device 600 to complete the motor control method described above.

[0143] In another exemplary embodiment, a computer program product is also provided, which contains a computer program capable of being executed by a programmable device, and the computer program has code portions for executing the motor control method described above when executed by the programmable device.

[0144] The preferred embodiments of the present disclosure are described in detail above with reference to the accompanying drawings, but the present disclosure is not limited to the specific details in the above-described embodiments. Within the technical concept range of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all belong to the protection scope of the present disclosure.

[0145] In addition, it should be noted that each specific technical feature described in the above specific embodiments can be combined in any appropriate manner without contradiction, and in order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0146] In addition, any combination of various different embodiments of the present disclosure can also be made, as long as it does not deviate from the idea of the present disclosure, and it should also be considered as disclosed by the present disclosure.

Claims

1. A method of controlling an electric machine, characterized by, The motor control method comprises: determining the thermal resistance of each MOS tube in the motor and the total power consumption, and the target environment temperature of a target MOS tube provided with a temperature sensor in the motor; determining the target environment temperature of each remaining MOS tube in the motor other than the target MOS tube according to the target environment temperature and a preset data fitting relationship, the preset data fitting relationship being a data fitting relationship between the environment temperature of the target MOS tube and the environment temperature of each remaining MOS tube; determining the junction temperature of each MOS tube in the motor according to the target environment temperature of each MOS tube in the motor and the thermal resistance and total power consumption of each MOS tube; controlling the operating state of the motor according to the junction temperature of each MOS tube in the motor; wherein the preset data fitting relationship is obtained by: determining, by the temperature sensor, a plurality of first environment temperatures of the target MOS tube when the motor is in a preset working state, the preset working state including a first operating state in which the motor works in a UV phase, a second operating state in which the motor works in a UW phase, and a third operating state in which the motor works in a VW phase; measuring, for each first environment temperature, a second environment temperature of each remaining MOS tube of the motor in the preset working state to obtain a plurality of second environment temperatures; performing data fitting on the plurality of first environment temperatures and the plurality of second environment temperatures in the same preset working state to obtain the preset data fitting relationship.

2. The motor control method according to claim 1, characterized by, The determination of the junction temperature of each MOS tube in the motor according to the target environment temperature of each MOS tube in the motor and the thermal resistance and total power consumption of each MOS tube comprises: determining the junction temperature of the target MOS tube according to the target environment temperature of the target MOS tube and the thermal resistance and total power consumption of the target MOS tube; filtering the target environment temperature of each remaining MOS tube to obtain a filtered environment temperature of each remaining MOS tube, and determining the junction temperature of each remaining MOS tube according to the filtered environment temperature of each remaining MOS tube and the thermal resistance and total power consumption of each remaining MOS tube.

3. The motor control method according to claim 2, characterized by, The filtering of the target environment temperature of each remaining MOS tube to obtain the filtered environment temperature of each remaining MOS tube comprises: filtering the target environment temperature of each remaining MOS tube by a Kalman filtering method to obtain the filtered environment temperature of each remaining MOS tube; or filtering the target environment temperature of each remaining MOS tube by a Kalman filtering method and a first-order RC low-pass filtering method to obtain the filtered environment temperature of each remaining MOS tube.

4. The motor control method of claim 1, wherein The determination of the junction temperature of each MOS tube in the motor according to the target environment temperature of each MOS tube in the motor and the thermal resistance and total power consumption of each MOS tube comprises: multiplying the thermal resistance and total power consumption of each MOS tube in the motor to obtain a third environment temperature of each MOS tube; The target environment temperature of each MOS tube is added to a third environment temperature to obtain a junction temperature of each MOS tube in the motor.

5. The method of claim 1-4, wherein, The method further comprises: The method further comprises:

6. The motor control method according to claim 5, characterized by, The method further comprises: When the junction temperature of any one of the MOS tubes in the motor reaches the preset temperature threshold, the operation state of the motor is controlled to be a stop operation state.

7. The motor control method of claim 5, wherein, When the working state of the motor is a non-stall working state, the method further comprises: When the junction temperature of each MOS tube in the motor does not reach the preset temperature threshold, the duty cycle of the motor is reduced to keep the motor in the operation state.

8. The motor control method of claim 5, wherein, When the working state of the motor is a stall working state, the method further comprises: In the MOS tubes of the motor, a MOS tube with the lowest junction temperature is determined. When the junction temperature of each MOS tube in the motor does not reach the preset temperature threshold, the MOS tube with the lowest junction temperature is controlled to enter an operation state to keep the motor in the operation state.

9. A non-transitory computer-readable storage medium having stored thereon a computer program, characterized in that, The program is executed by the processor to implement the steps of the method of any one of claims 1-8.

10. A controller characterized by comprising: The method further comprises: A memory having a computer program stored thereon; The processor is configured to execute the computer program in the memory to implement the steps of the method of any one of claims 1-8.

11. An electric machine characterized by The motor comprises a plurality of MOS tubes and the controller of claim 10.

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