Driving device for airborne refrigeration compressor and control method

Abstract

The invention belongs to the technical field of compressor driving control, and particularly relates to an airborne refrigeration compressor driving device and a control method, a position vector-free control mode is combined with HALL position sensor-based control, and the real-time rotor position of a compressor is obtained through a position signal fault-tolerant selection processing method. And high-reliability driving of the airborne refrigeration compressor is realized. According to the method, high-reliability stable operation control of the aviation airborne refrigeration compressor can be realized, and the problem of unreliable operation in a low-speed stage of position-free vector control and the problem of out-of-step of the compressor caused by an airborne power supply characteristic test in a medium-high-speed stage are solved. The rotor position information calculated based on the HALL position sensor is adopted to correct the position information estimated by the position-free control algorithm, so that the accuracy of position estimation is improved; a control mode is adopted for fault tolerance, when it is detected that the motor is out of step, square wave control based on the HALL position sensor is immediately switched to, stable operation of the compressor is ensured, and the operation reliability of the aviation airborne refrigeration compressor is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of compressor drive control, and in particular relates to a drive device and a control method for an onboard refrigeration compressor.

[0002] With the development of more-electric and all-electric aircraft technology, the number of airborne electronic equipment has increased rapidly. The heat dissipation of airborne electronic equipment adopts a two-stage heat dissipation system based on evaporation cycle, which has the advantages of high heat dissipation efficiency and controllable temperature. It has gradually become a hot spot in the research of aviation airborne equipment heat dissipation system. As the core component, it is particularly important to improve the reliability of the operation of the airborne refrigeration compressor.

[0003] With the development of new airborne laser equipment, laser equipment works frequently in a short time, which requires the airborne refrigeration system to quickly and quickly exchange a large amount of heat. This requires the refrigeration system to operate reliably and be able to start and stop quickly. Usually, the compressor adopts positionless vector control. Conventional positionless compressor drive has unreliable operation in the complex electromagnetic environment of aviation, and because it takes time to balance the inlet and outlet pressures of the compressor, it is impossible to achieve rapid start and stop. In view of the many defects of conventional positionless compressor drive in the field of aviation airborne refrigeration, a high-reliability drive device and control method for airborne refrigeration compressors are designed. Summary of the invention

[0004] The purpose of the present invention is to propose a high-reliability drive device and control method for an airborne refrigeration compressor to solve the technical problems of unreliable operation of the current positionless compressor drive in the complex electromagnetic environment of aviation and the inability of the compressor to start and stop quickly.

[0005] In order to achieve the above-mentioned purpose, the present invention proposes a control method for an onboard refrigeration compressor, which mainly adopts position-free vector control and has position square wave drive as backup control.

[0006] Evaluate the status of the HALL position sensor, output whether the HALL sensor is normal or faulty, and estimate the motor Hall angle θ HALL ;

[0007] The compressor driving voltage and current U α、 U β、 I α and I β As input, the estimated angle θ is obtained after the rotor position is estimated. smo ;

[0008] According to the motor Hall angle θ HALL , estimate the angle θ smo Combined with the HALL state control method, the driving mode and rotor angle θ of the compressor are obtained;

[0009] When the compressor is driven by vector control, I d =0 control mode, by giving the speed n ref The calculated compressor speed Speed ​​is used for PI control, and the quadrature axis current component given value is output. At the same time, the compressor phase current is transformed by Clark and Park to obtain the stator feedback current I d ,I q , through the dq axis current loop PI control, the output U d , U q , after IPARK transformation, output U α , U β , and then after SVPWM modulation, output 6-way PWM to the three-phase inverter to achieve sinusoidal wave drive;

[0010] When the compressor is driven by square wave control, the given speed n ref PI control is performed with the calculated compressor speed Speed ​​to output the duty cycle PWM of square wave drive; then phase switching control is performed according to the rotor angle θ, and the corresponding duty cycle PWM is output to the three-phase inverter to realize square wave drive of the compressor.

[0011] Furthermore, when evaluating the HALL sensor position, first determine whether the HALL sensor signal is all 1 or all 0. If the condition is met, the HALL sensor state is output as a fault; if the condition is not met, continue to determine whether the HALL state change sequence meets the set sequence. If the state change sequence does not meet the set sequence, the HALL sensor state is output as a fault; if the state change sequence meets the set sequence, continue to determine whether the single state continuous electrical angle of the HALL is greater than 70° or less than 50°. If the condition is met, the HALL sensor state is output as a fault; if the condition is not met, the HALL sensor state is output as normal.

[0012] Furthermore, at the motor Hall angle θ HALL When estimating, the following detections are performed in a loop: the A-phase Hall falling edge, the C-phase Hall rising edge, and the B-phase Hall falling edge are detected; if the A-phase Hall falling edge is detected, the motor Hall angle θ is output. HALL is 30°; if the C phase Hall rising edge is detected, the motor Hall angle θ is output HALL is 90°; if the B-phase Hall falling edge is detected, the motor Hall angle θ is output HALL is 150°; if the A phase Hall rising edge is detected, the motor Hall angle θ is output HALL is 210°; if the C phase Hall falling edge is detected, the motor Hall angle θ is output HALL is 270°; if the B phase Hall rising edge is detected, the motor Hall angle θ is output HALLis 330°; if no rising or falling edge is detected, the motor Hall angle θ is output HALL =θ old +Δt / 60*pole*Speed*360, where θ old is the last motor Hall angle, Δt is the duration since the last speed calculation, pole is the number of pole pairs, and Speed ​​is the current speed.

[0013] Furthermore, the driving mode of the compressor is selected in the following manner:

[0014] First, determine the status of the HALL sensor. When the HALL sensor fails, the position-free vector control method based on the synovial observer is used for control. When the HALL sensor is normal, determine the error value between the motor Hall angle and the estimated angle of the synovial observer. If it exceeds 90°, it means that the position-free control method has failed, and the square wave drive based on HALL is used. Otherwise, the motor Hall angle is used to correct the estimated angle of the synovial observer to achieve accurate drive of the position-free vector control.

[0015] Furthermore, the compressor rotor position is estimated by observing the stator current with a synovial film observer, estimating the back electromotive force of the compressor, and obtaining the compressor rotor position information based on the synovial film observer; and correcting the compressor rotor position information calculated based on the HALL position sensor.

[0016] Furthermore, the synovial observer designs a synovial current observer by constructing the state equation of the PMSM under the αβ axis, obtains an estimated value of the PMSM back electromotive force by controlling the error between the observed current and the feedback, and then obtains the estimated rotor angle by calculating the inverse tangent of the estimated back electromotive force. After a certain angle compensation, the final rotor position angle is obtained.

[0017] Furthermore, in the vector control mode, the direct axis given current I is controlled d =0, and the stator feedback direct axis current I obtained after transformation d In comparison, after passing through the d-axis current loop PI controller, the output direct-axis voltage U d , given quadrature axis current and transformed stator feedback quadrature axis current I q In comparison, after the q-axis current loop PI controller, the output quadrature-axis voltage U q , and then the αβ axis voltage is obtained through Park inverse transformation; finally, the SVPWM modulation module outputs six control signals to drive the three-phase inverter to work.

[0018] Furthermore, under the square wave control mode, a single speed loop control mode is adopted. By comparing the given speed signal with the detected speed signal, the PWM control quantity is output after adjustment by the speed loop PI controller; three-phase six-state commutation control is performed according to the HALL commutation angle, and a two-two conduction control mode is selected in each state. At any moment, there is always one phase that is not conducting; in the two-two conduction mode, the conduction control of the three-phase bridge switch tube is executed according to the set control law.

[0019] On the other hand, the present invention also proposes a driving device for an onboard refrigeration compressor, the driving device comprising a filter circuit unit, a three-phase bridge circuit unit, a driving circuit unit, a phase current acquisition circuit unit, a HALL acquisition and conditioning circuit unit, and a controller;

[0020] The positive electrode of the high-voltage DC 270V power supply passes through the filter circuit to remove the interference signal on the power line and then supplies power to the positive electrode of the busbar of the three-phase bridge circuit. The drive circuit controls the three-phase bridge circuit to convert the 270V DC power supply into a three-phase AC power supply to drive the compressor to work. The negative electrode of the busbar of the three-phase bridge returns to the negative electrode of the high-voltage DC 270V power supply through the filter circuit to form a power supply loop.

[0021] The 0~+15V signal of the compressor three-phase HALL position sensor is converted into a 0~+3.3V signal by the HALL acquisition and conditioning circuit and input to the controller for estimating the motor Hall angle;

[0022] The two-phase current of the compressor is converted into a 0-3V analog voltage signal by the phase current acquisition circuit and input to the controller for the sliding film observer to estimate the motor rotor position;

[0023] The controller receives instructions from the host computer, and estimates the angle based on the motor Hall angle and the sliding film observer, performs control mode fault tolerance, determines the drive mode and controls the output of 6 PWM signals to the drive circuit. The drive circuit converts the 6 PWM signals into positive and negative drive signals suitable for driving the power tube, controls the on and off of the power tube, and realizes the function of the three-phase bridge circuit driving the compressor.

[0024] Technical effect: The present invention evaluates the state of the position sensor in real time, estimates the compressor rotor position information, estimates the compressor rotor position information based on HALL through the Hall sensor, and performs control mode fault tolerance through control mode fault tolerance processing. When the position-free vector control fails, it can switch to backup control with position square wave drive. At the same time, when there is no position vector control, the compressor rotor position is corrected and compensated in real time through the compressor rotor position information based on HALL, so as to realize accurate control of the compressor rotor position.

[0025] The control method proposed in the present invention can realize stable and reliable operation and rapid start-stop control of aircraft-borne refrigeration compressors in complex electromagnetic environments. It can meet the short-term high-power refrigeration needs of airborne equipment and solve the problem of rapid and frequent start-up loss of aircraft-borne compressors. The present invention significantly improves the reliability of the operation of aircraft-borne refrigeration compressors through fault-tolerant control of the drive device. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a principle block diagram of the compressor driving device of the present invention;

[0027] Figure 2 This is a principle block diagram of the compressor driving device control method of the present invention;

[0028] Figure 3 is a flow chart of the position sensor state evaluation of the present invention;

[0029] Figure 4 This is a flow chart of the implementation of the present invention based on the HALL position estimation module;

[0030] Figure 5 A schematic diagram of fault-tolerant selection of the control mode of the present invention;

[0031] Figure 6 This is a control principle diagram of the synovial state observer of the present invention;

[0032] Figure 7 This is a block diagram of the vector control principle used in the implementation process of the present invention;

[0033] Figure 8 This is a logic block diagram of the square wave control law used in the implementation of the present invention. DETAILED DESCRIPTION

[0034] In order to more clearly illustrate the technical solution of the embodiment of the present invention, the present invention is described in detail below in conjunction with the drawings or specific implementation cases of the specification. It should be noted that some (but not all) of the disclosed examples are shown in the drawings. In fact, many different examples can be described and these examples should not be understood as being limited to the examples set forth herein. On the contrary, these examples are described so that the positive effects of the present invention are more reflected, and any parts not detailed in the text are regarded as known techniques or conventional technical means in the art.

[0035] The present invention proposes a high-reliability drive control method for an airborne refrigeration compressor, which mainly adopts position-free vector control and position square wave drive as backup control. The state of the sensor is evaluated in real time by a position sensor state evaluation module, and the compressor rotor position information based on the synovial observer is estimated by a synovial observer. The compressor rotor position information based on HALL is estimated by a Hall sensor. The control mode fault tolerance is performed through control mode fault tolerance processing. When the position-free vector control fails, it can be switched to the backup control with position square wave drive. At the same time, when there is no position vector control, the compressor rotor position is corrected and compensated in real time by the compressor rotor position information based on HALL, so as to realize accurate control of the compressor rotor position.

[0036] Based on the above design concept, an onboard refrigeration compressor driving device is designed in the specific implementation process of the present invention, including a filter circuit, a three-phase bridge circuit, a phase current acquisition circuit, a HALL acquisition circuit, a drive circuit, and a DSP28335 controller. The specific structural principle block diagram is shown in FIG. Figure 1 As shown; a phase current acquisition circuit for positionless vector control is combined with a Hall acquisition circuit for position square wave control to realize redundant backup control of positionless vector control and position square wave control; in the designed drive device, a high-voltage DC 270V power supply is used as input, and the positive electrode of the high-voltage DC 270V power supply passes through a filtering circuit to remove interference signals on the power line and then supplies power to the positive electrode of the busbar of the three-phase bridge circuit. The 270V DC power supply is converted into a three-phase AC power supply to drive the compressor through the control of the three-phase bridge circuit of the drive circuit, and the negative electrode of the busbar of the three-phase bridge returns to the negative electrode of the high-voltage DC 270V power supply through the filtering circuit to form a power supply loop.

[0037] The 0~+15V signal of the compressor three-phase HALL position sensor is converted into a 0~+3.3V signal by the HALL acquisition and conditioning circuit and input to the DSP28335 controller for estimating the motor Hall angle.

[0038] The two-phase current of the compressor is converted into a 0-3V analog voltage signal by the phase current acquisition circuit and input into the DSP28335 controller for the sliding film observer to estimate the motor rotor position.

[0039] The DSP28335 controller receives commands from the host computer through the RS422 bus, and estimates the angle based on the motor Hall angle and the sliding film observer, performs fault tolerance in the control mode, determines the drive mode and controls the output of 6 PWM signals to the drive circuit. The drive circuit converts the 6 PWM signals into positive and negative drive signals suitable for driving the power tube, controls the on and off of the power tube, and realizes the function of driving the compressor with a three-phase bridge circuit.

[0040] The control method of this scheme includes vector control module, square wave control module, position sensor state evaluation module, synovial observer, HALL-based position estimation module, control mode fault tolerance module, etc. Its control principle block diagram is as follows: Figure 2 shown.

[0041] The status of the HALL position sensor is evaluated through the position sensor status evaluation module, and the output of the HALL sensor status is normal or faulty, and the motor Hall angle θ is estimated based on the HALL position estimation module. HALL ;

[0042] Compressor drive voltage and current U α、 U β、 I α and I β Input to the synovial observer module to estimate the rotor position and obtain the synovial observer estimated angle θ smo ;

[0043] Motor Hall Angle θ HALL , the synovial observer estimates the angle θ smo , the Hall state control mode fault tolerance module obtains the compressor driving mode and rotor angle θ;

[0044] When the compressor is driven by vector control, I d =0 control mode, by giving the speed n ref The compressor speed Speed ​​calculated by the speed calculation module is controlled by PI, and the quadrature axis current component given value is output. At the same time, the compressor phase current is transformed by Clark and Park to obtain the stator feedback current I d ,I q , through the dq axis current loop PI control, the output U d , U q , after IPARK transformation, output U α , U β , and then after SVPWM modulation, 6-way PWM is output to the three-phase inverter to achieve sinusoidal wave drive.

[0045] When the compressor is driven by square wave control, the speed n is given. ref The compressor speed Speed ​​calculated by the speed calculation module is controlled by PI, and the duty cycle PWM of square wave drive is output. The three-phase six-state commutation control module performs commutation control according to the rotor angle θ, and outputs the corresponding PWM to the three-phase inverter to realize square wave drive of the compressor.

[0046] In a specific implementation case, see Attachment Figure 3As shown, the position sensor state is evaluated, and the specific evaluation process is: first, determine whether the HALL sensor signal is all 1 or all 0. If the condition is met, the HALL sensor state is output as a fault; if the condition is not met, continue to determine whether the HALL state change sequence satisfies 5, 1, 3, 2, 6, 4 or 5, 4, 6, 2, 3, 1 (this change sequence is one of the setting forms, which can be specifically set according to the product model and application scenario). If the state change sequence does not meet the condition, the HALL sensor state is output as a fault; if the state change sequence meets the condition, continue to determine whether the single state continuous electrical angle of the HALL is greater than 70° or less than 50°. If the condition is met, the HALL sensor state is output as a fault; if the condition is not met, the HALL sensor state is output as normal.

[0047] In the above implementation, the motor Hall angle θ HALL For estimation, see Appendix Figure 4 The specific implementation process is: cyclic detection and judgment in sequence: A phase Hall falling rising edge, C phase Hall rising edge, B phase Hall falling rising edge; if the A phase Hall falling rising edge is detected, the motor Hall angle θ is output HALL is 30°; if the C phase Hall rising edge is detected, the motor Hall angle θ is output HALL is 90°; if the B-phase Hall falling edge is detected, the motor Hall angle θ is output HALL is 150°; if the A phase Hall rising edge is detected, the motor Hall angle θ is output HALL is 210°; if the C phase Hall falling edge is detected, the motor Hall angle θ is output HALL is 270°; if the B phase Hall rising edge is detected, the motor Hall angle θ is output HALL is 330°; if no rising or falling edge is detected, the motor Hall angle θ is output HALL =θ old +Δt / 60*pole*Speed*360, where θ old is the last motor Hall angle, Δt is the duration since the last speed calculation, pole is the number of pole pairs, and Speed ​​is the current speed.

[0048] In the drive device specifically designed by the present invention, the control mode fault tolerance module selects the control mode according to the current position sensor state. The selection process is shown in the attached Figure 5As shown; first determine the state of the HALL sensor. When the HALL sensor fails, the positionless vector control method based on the synovial observer is used for control; when the HALL sensor is normal, determine the error value between the motor Hall angle and the estimated angle of the synovial observer. If it exceeds 90°, it means that the positionless control method has failed. Therefore, the square wave drive based on HALL is adopted. Otherwise, the motor Hall angle is used to correct the estimated angle of the synovial observer to achieve accurate drive of the positionless vector control and improve the reliability of the positionless vector control.

[0049] Implementation Case 1: Taking a certain type of airborne refrigeration compressor drive control design as an example, the drive device and control method proposed in the present invention are adopted; in the design of the drive device, the position sensor state evaluation module in the device extracts the HALL sensor fault characteristics by analyzing the HALL sensor fault mode. The fault characteristics include: HALL sensor signals are all 1, HALL sensor signals are all 0, the HALL state change sequence is incorrect, and the duration of a single state during operation is not 60°. The position sensor state evaluation process is designed based on the fault characteristics.

[0050] The synovial observer is designed by constructing the state equation of PMSM under the αβ axis, designing the synovial current observer, and obtaining the estimated value of the PMSM back electromotive force by controlling the error between the observed current and the feedback. Then, the estimated rotor angle is obtained by calculating the inverse tangent of the estimated back electromotive force. After a certain angle compensation, the final rotor position angle is obtained. The control principle of the device is as follows: Figure 8 shown.

[0051] Based on the HALL position estimation module, the Hall state change point is first used to determine the motor rotor position points of 30°, 90°, 150°, 310°, 270°, and 330°. The rotor position and the corresponding angle of the Hall state are shown in Table 1. Then, the motor rotation inertia characteristics are used. The motor speed will not change suddenly. According to the motor speed and rotation time, the rotor position of other positions is determined. The principle is that the motor Hall angle θ = θ old +Δt / 60*pole*Speed*360, where θ old is the last rotor position angle, Δt is the duration since the last speed calculation, pole is the number of pole pairs, and Speed ​​is the current speed.

[0052] Table 1 Correspondence between rotor position and Hall state

[0053] Serial number Hall state Motor rotor angle 1 A phase Hall falling edge 30° 2 C phase Hall rising edge 90° 3 B phase Hall falling edge 150° 4 A phase Hall rising edge 210° 5 C phase Hall falling edge 270° 6 B phase Hall rising edge 330°

[0054] In the design of the fault-tolerant module of the specific control mode, the module performs fault tolerance processing according to the evaluation results of the sensor state by the position sensor state evaluation module, as well as the Hall estimated angle and the synovial observer estimated angle. When the HALL sensor fails, the position-free vector control method based on the synovial observer is used for control; when the HALL sensor is normal, when the error between the Hall estimated angle and the synovial observer estimated angle exceeds 90°, it means that the position-free control method has failed and the motor has lost step, so the square wave drive based on HALL is used, otherwise the Hall estimated angle is used to correct the synovial observer estimated angle, so as to realize the accurate drive of the position-free vector control and improve the reliability of the position-free vector control.

[0055] 1) The vector control module uses I d =0 control mode, by comparing the given speed signal with the detected speed signal, after adjustment by the speed loop PI controller, the quadrature axis current component is output and used as the given signal of the current loop PI controller. At the same time, the compressor phase current is transformed into coordinates to obtain the stator feedback current I d ,I q , control the direct axis given current I d =0, and the stator feedback direct axis current I obtained after transformation d In comparison, after passing through the d-axis current loop PI controller, the output direct-axis voltage U d , given quadrature axis current and transformed stator feedback quadrature axis current I q In comparison, after the q-axis current loop PI controller, the output quadrature-axis voltage U q , and then the αβ axis voltage is obtained through Park inverse transformation. Finally, the SVPWM modulation module outputs six control signals to drive the three-phase inverter to work, and outputs three-phase sinusoidal current with variable amplitude and frequency to drive the compressor to work. The control principle is as follows Figure 7 shown.

[0056] 2) The square wave control module adopts a single speed loop control mode. By comparing the given speed signal with the detected speed signal, the PWM control quantity is output after adjustment by the speed loop PI controller. The three-phase six-state commutation control module performs commutation control according to the HALL commutation angle. In each state, a two-two conduction control mode is selected. At any moment, there is always one phase that is not conducting. In the two-two conduction mode, the conduction rule of the three-phase bridge switch tube is as follows: Figure 8 shown.

[0057] The refrigeration compressor drive control method designed by the present invention is a high-reliability compressor drive device and control algorithm based on position sensorless drive as the main part and HALL position sensor drive as the auxiliary part; the present invention adopts a positionless vector control method combined with a control based on a HALL position sensor, and obtains the real-time rotor position of the compressor through a position signal fault-tolerant selection processing method, thereby realizing high-reliability drive of the onboard refrigeration compressor; the present invention can realize high-reliability stable operation control of aviation onboard refrigeration compressors, and solves the problem of unreliable operation of positionless vector control at low speed stage and the problem of compressor loss of step caused by the onboard power supply characteristic test at medium and high speed stage. The rotor position information calculated based on the HALL position sensor is used to correct the position information estimated by the positionless control algorithm, thereby improving the accuracy of position estimation; the control method is fault-tolerant, and when the motor is detected to be out of step, it is immediately switched to square wave control based on the HALL position sensor, which can ensure the stable operation of the compressor and significantly improve the reliability of the operation of the aviation onboard refrigeration compressor.

[0058] The above specific implementation methods or cases are only used to explain the technical solutions of the present invention, and are not intended to limit the present application. Any parts not described in detail are deemed to be conventional technical means or common knowledge in the field. It can be understood by ordinary technicians in this field that: based on the design concept of the present application, the technical solutions recorded in the aforementioned implementation methods should be adaptively modified, or some or all of the technical features therein should be replaced by equivalents. These modifications, equivalent replacements, and adaptively improved technical solutions do not depart from the technical essence of the present invention and should all be covered within the protection scope of the present application.

Claims

1. A method for controlling an onboard refrigeration compressor, characterized in that: It mainly adopts position-free vector control, and position square wave drive as backup control. Evaluate the status of the HALL position sensor, output whether the HALL sensor is normal or faulty, and estimate the motor Hall angle θ HALL ; The compressor driving voltage and current U α、 U β、 I α and I β As input, the estimated angle θ is obtained after the rotor position is estimated. smo ; According to the motor Hall angle θ HALL , estimate the angle θ smo Combined with the HALL state control method, the driving mode and rotor angle θ of the compressor are obtained; When the compressor is driven by vector control, I d =0 control mode, by giving the speed n ref The calculated compressor speed Speed ​​is used for PI control, and the quadrature axis current component given value is output. At the same time, the compressor phase current is transformed by Clark and Park to obtain the stator feedback current I d ,I q , through the dq axis current loop PI control, the output U d , U q , after IPARK transformation, output U α , U β , and then after SVPWM modulation, output 6-way PWM to the three-phase inverter to achieve sinusoidal wave drive; When the compressor is driven by square wave control, the given speed n ref PI control is performed with the calculated compressor speed Speed ​​to output the duty cycle PWM of square wave drive; then phase switching control is performed according to the rotor angle θ, and the corresponding duty cycle PWM is output to the three-phase inverter to realize square wave drive of the compressor.

2. A method for controlling an onboard refrigeration compressor according to claim 1, characterized in that: When evaluating the HALL sensor position, first determine whether the HALL sensor signal is all 1 or all 0. If the condition is met, the HALL sensor status is output as a fault. If the condition is not met, continue to determine whether the HALL state change sequence meets the set sequence. If the state change sequence does not meet the set sequence, the HALL sensor status is output as a fault. If the state change sequence meets the set sequence, continue to determine whether the continuous electrical angle of a single state of the HALL is greater than 70° or less than 50°. If the condition is met, the HALL sensor status is output as a fault. If the condition is not met, the HALL sensor status is output as normal.

3. A method for controlling an onboard refrigeration compressor according to claim 2, characterized in that: At the motor Hall angle θ HALL During estimation, the following detections are performed in a circular manner: the A-phase Hall rising edge, the C-phase Hall rising edge, and the B-phase Hall rising edge are detected; If the A phase Hall falling edge is detected, the motor Hall angle θ is output HALL is 30°; if the C phase Hall rising edge is detected, the motor Hall angle θ is output HALL is 90°; if the B-phase Hall falling edge is detected, the motor Hall angle θ is output HALL is 150°; if the A phase Hall rising edge is detected, the motor Hall angle θ is output HALL is 210°; if the C phase Hall falling edge is detected, the motor Hall angle θ is output HALL is 270°; if the B phase Hall rising edge is detected, the motor Hall angle θ is output HALL is 330°; if no rising or falling edge is detected, the motor Hall angle θ is output HALL =θ old +Δt / 60*pole*Speed*360, where θ old is the last motor Hall angle, Δt is the duration since the last speed calculation, pole is the number of pole pairs, and Speed ​​is the current speed.

4. A method for controlling an onboard refrigeration compressor according to claim 1, characterized in that: The drive mode of the compressor is selected in the following ways: First, determine the status of the HALL sensor. When the HALL sensor fails, the position-free vector control method based on the synovial observer is used for control. When the HALL sensor is normal, determine the error value between the motor Hall angle and the estimated angle of the synovial observer. If it exceeds 90°, it means that the position-free control method has failed, and the square wave drive based on HALL is used. Otherwise, the motor Hall angle is used to correct the estimated angle of the synovial observer to achieve accurate drive of the position-free vector control.

5. The method for controlling an onboard refrigeration compressor according to claim 1, characterized in that: The compressor rotor position is estimated by observing the stator current with a synovial film observer, estimating the back electromotive force of the compressor, and obtaining the compressor rotor position information based on the synovial film observer; and the compressor rotor position information calculated based on the HALL position sensor is used for correction.

6. A method for controlling an onboard refrigeration compressor according to claim 5, characterized in that: The synovial observer designs a synovial current observer by constructing the state equation of the PMSM under the αβ axis, obtains an estimated value of the PMSM back electromotive force by controlling the error between the observed current and the feedback, and then obtains the estimated rotor angle by calculating the inverse tangent of the estimated back electromotive force. After a certain angle compensation, the final rotor position angle is obtained.

7. A method for controlling an onboard refrigeration compressor according to claim 1, characterized in that: In vector control mode, control the direct axis given current I d =0, and the stator feedback direct axis current I obtained after transformation d In comparison, after passing through the d-axis current loop PI controller, the output direct-axis voltage U d , given quadrature axis current and transformed stator feedback quadrature axis current I q In comparison, after the q-axis current loop PI controller, the output quadrature-axis voltage U q , and then the αβ axis voltage is obtained through Park inverse transformation; finally, the SVPWM modulation module outputs six control signals to drive the three-phase inverter to work.

8. A method for controlling an onboard refrigeration compressor according to claim 7, characterized in that: In the square wave control mode, a single speed loop control mode is adopted. By comparing the given speed signal with the detected speed signal, the PWM control quantity is output after adjustment by the speed loop PI controller; three-phase six-state commutation control is performed according to the HALL commutation angle, and a two-two conduction control mode is selected in each state. At any moment, there is always one phase that is not conducting; in the two-two conduction mode, the conduction control of the three-phase bridge switch tube is executed according to the set control law.

9. A driving device for an onboard refrigeration compressor, characterized in that: The driving device includes a filter circuit unit, a three-phase bridge circuit unit, a driving circuit unit, a phase current acquisition circuit unit, a HALL acquisition and conditioning circuit unit, and a controller; The positive electrode of the high-voltage DC 270V power supply passes through the filter circuit to remove the interference signal on the power line and then supplies power to the positive electrode of the busbar of the three-phase bridge circuit. The drive circuit controls the three-phase bridge circuit to convert the 270V DC power supply into a three-phase AC power supply to drive the compressor to work. The negative electrode of the busbar of the three-phase bridge returns to the negative electrode of the high-voltage DC 270V power supply through the filter circuit to form a power supply loop. The 0~+15V signal of the compressor's three-phase HALL position sensor is converted into a 0~+3.3V signal through the HALL acquisition and conditioning circuit, and input into the controller for estimating the motor's Hall angle; the two-phase current of the compressor is converted into a 0~3V analog voltage signal through the phase current acquisition circuit, and input into the controller for the synovial observer to estimate the motor's rotor position; the controller receives instructions from the host computer, and performs control mode fault tolerance based on the motor's Hall angle and the estimated angle of the synovial observer, determines the drive mode and controls the output of 6 PWM signals to the drive circuit. The drive circuit converts the 6 PWM signals into positive and negative drive signals suitable for driving the power tube, controls the on and off of the power tube, and realizes the function of the three-phase bridge circuit driving the compressor.

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