Full-speed range belt speed re-throw method, device, equipment and medium for permanent magnet synchronous motor

Abstract

The present invention discloses a full-speed range speed re-throw method, device, equipment and medium for a permanent magnet synchronous motor. By judging whether the back electromotive force of the permanent magnet synchronous motor is greater than the DC side bus voltage; if so, the isolation contactor of the permanent magnet synchronous motor is controlled to close, and the three-phase bridge arm state information of the permanent magnet synchronous motor is determined according to the three-phase current information of the permanent magnet synchronous motor and the correspondence table between the three-phase current and the three-phase bridge arm state, the three-phase voltage information of the permanent magnet synchronous motor is constructed according to the DC side bus voltage of the permanent magnet synchronous motor and the three-phase bridge arm state information, and the first rotor position angle of the permanent magnet synchronous motor is calculated according to the three-phase voltage information, and the speed re-throw operation is performed using the first rotor position angle; if not, the speed re-throw operation is performed by the short-circuit current method. The scheme of the present application can perform the speed re-throw operation in the full speed range of the permanent magnet synchronous motor, ensuring that the rotor position of the motor is accurately obtained under any working condition.

Description

Technical Field

[0001] The present invention relates to the field of permanent magnet synchronous motor traction technology, and in particular to a full-speed range belt speed re-throw method, device, equipment and medium for a permanent magnet synchronous motor. Background Art

[0002] When the permanent magnet synchronous motor is running, a back electromotive force proportional to the speed is generated on the stator. For safety reasons, an isolation contactor is installed between the inverter and the permanent magnet synchronous motor to close and disconnect the connection between the inverter and the permanent magnet synchronous motor. The speed re-start of the permanent magnet synchronous motor refers to the inverter being put into operation when the permanent magnet synchronous motor is running at speed, that is, closing the isolation contactor and connecting the inverter to the permanent magnet synchronous motor. In order to control the permanent magnet synchronous motor through the inverter, it is generally necessary to detect or estimate the current position of the motor rotor to control the stator current or voltage to prevent overcurrent. Since installing a position sensor to detect the position of the rotor will bring many disadvantages, such as increased volume, weight, cost, etc., position sensorless control technology has gradually developed into a current research hotspot.

[0003] In the prior art, the short-circuit current method is usually used to estimate the position of the rotor, that is, in the zero initial state, a short zero vector pulse is sent, and then the rotor position is calculated based on the current change of the motor and the parameters of the motor during this period. However, this method requires a three-phase zero initial state, that is, the three-phase current needs to be zero when the belt speed is re-thrown, but the three isolation contactors are mechanical devices, and there are many combination types, and the closing time cannot be completely consistent. In this way, there will be a short-term two-phase closed and the third phase is not closed. The phase-loss state. When the motor speed is high, the back electromotive force generated may be higher than the DC side bus voltage, resulting in energy re-injection. At this time, it is a zero initial state with current. Using the short-circuit current method to estimate the rotor position will result in excessive deviation, which is easy to cause overcurrent during the belt speed re-throw process.

[0004] In view of this, how to provide a solution that can solve the above technical problems is a technical problem that people in the relevant technical field need to solve. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a full-speed range speed re-throw method, device, equipment and medium for a permanent magnet synchronous motor, which can perform speed re-throw operations in the full speed range of the permanent magnet synchronous motor to ensure that the rotor position of the motor is accurately obtained under any working conditions.

[0006] On one hand, the present invention provides a full-speed range belt speed re-start method for a permanent magnet synchronous motor, comprising:

[0007] Determine whether the back electromotive force of the permanent magnet synchronous motor is greater than the DC side bus voltage;

[0008] If so, control the isolation contactor of the permanent magnet synchronous motor to close, determine the three-phase bridge arm state information of the permanent magnet synchronous motor according to the three-phase current information of the permanent magnet synchronous motor and the correspondence table between the three-phase current and the three-phase bridge arm state, construct the three-phase voltage information of the permanent magnet synchronous motor according to the DC side bus voltage of the permanent magnet synchronous motor and the three-phase bridge arm state information, calculate the first rotor position angle of the permanent magnet synchronous motor according to the three-phase voltage information, and perform the belt speed re-throw operation using the first rotor position angle;

[0009] If not, the permanent magnet synchronous motor is controlled to be in a short-circuit state, and the first short-circuit current phase angle in the stationary coordinate system is calculated according to the three-phase current information of the permanent magnet synchronous motor in the short-circuit state; the second short-circuit current phase angle in the rotating coordinate system is calculated according to the duration of the permanent magnet synchronous motor in the short-circuit state; the second rotor position angle of the permanent magnet synchronous motor is obtained according to the difference between the second short-circuit current phase angle and the first short-circuit current phase angle, and the second rotor position angle is used to perform the belt speed re-throw operation.

[0010] Preferably, the correspondence table between the three-phase current and the three-phase bridge arm state is calibrated in the following manner:

[0011] During the duration of the isolating contactor performing the closing action, the three-phase current sampling information and the three-phase bridge arm state sampling information of the permanent magnet synchronous motor are periodically recorded to obtain a corresponding relationship table between the three-phase current and the three-phase bridge arm state.

[0012] Preferably, calculating the first rotor position angle of the permanent magnet synchronous motor according to the three-phase voltage information includes:

[0013] Calculate the direct-axis voltage and quadrature-axis voltage in a rotating coordinate system according to the three-phase voltage information and the circuit topology of the permanent magnet synchronous motor;

[0014] Calculate the direct-axis current and the quadrature-axis current in the rotating coordinate system according to the direct-axis voltage and the quadrature-axis voltage;

[0015] A first rotor position angle of the permanent magnet synchronous motor is calculated according to the direct-axis current and the quadrature-axis current.

[0016] Preferably, calculating the direct-axis current and the quadrature-axis current in the rotating coordinate system according to the direct-axis voltage and the quadrature-axis voltage includes:

[0017] The direct-axis current and quadrature-axis current in the rotating coordinate system are calculated using the following formula:

[0018] ;

[0019] in, u d and u q represent the direct-axis voltage and quadrature-axis voltage respectively, Rrepresents the stator resistance, p represents the differential operator, L d and L q Represent the direct-axis inductance and quadrature-axis inductance respectively. oh e represents the electrical angular velocity, and represent the direct-axis current and quadrature-axis current respectively, P f represents the permanent magnet flux;

[0020] The first rotor position angle of the permanent magnet synchronous motor is calculated according to the direct axis current and the quadrature axis current, including:

[0021] The first rotor position angle of the permanent magnet synchronous motor is calculated by the following formula:

[0022] ;

[0023] in, Represents the first rotor position angle of the permanent magnet synchronous motor.

[0024] Preferably, calculating the first short-circuit current phase angle in a stationary coordinate system according to the three-phase current information of the permanent magnet synchronous motor in a short-circuit state includes:

[0025] The first short-circuit current phase angle is calculated by the following formula:

[0026] ;

[0027] in, represents the first short-circuit current phase angle, and Represents the current components of the three-phase current of the permanent magnet synchronous motor in the short-circuit state in the stationary coordinate system.

[0028] Preferably, calculating the second short-circuit current phase angle in the rotating coordinate system according to the duration that the permanent magnet synchronous motor is in the short-circuit state includes:

[0029] The second short-circuit current phase angle is calculated by the following formula:

[0030] ;

[0031] in, represents the second short-circuit current phase angle, and represents the current component in the rotating coordinate system, and Represent the direct-axis inductance and quadrature-axis inductance respectively. represents the electrical angular velocity, represents the permanent magnet flux, T Represents the duration that the permanent magnet synchronous motor is in a short-circuit state.

[0032] Preferably, the back electromotive force of the permanent magnet synchronous motor is calculated by the following formula:

[0033] ;

[0034] in, represents the back EMF of the permanent magnet synchronous motor, represents the electrical angular velocity, Represents the permanent magnet flux.

[0035] Another aspect of the present invention provides a full-speed range belt speed re-throw device for a permanent magnet synchronous motor, comprising:

[0036] A judgment module, used to judge whether the back electromotive force of the permanent magnet synchronous motor is greater than the DC side bus voltage;

[0037] A first execution module is used for controlling the closing of the isolation contactor of the permanent magnet synchronous motor when the determination result of the determination module is yes, determining the three-phase bridge arm state information of the permanent magnet synchronous motor according to the three-phase current information of the permanent magnet synchronous motor and the correspondence table between the three-phase current and the three-phase bridge arm state, constructing the three-phase voltage information of the permanent magnet synchronous motor according to the DC side bus voltage of the permanent magnet synchronous motor and the three-phase bridge arm state information, calculating the first rotor position angle of the permanent magnet synchronous motor according to the three-phase voltage information, and performing the belt speed re-throw operation using the first rotor position angle;

[0038] The second execution module is used to control the permanent magnet synchronous motor to be in a short-circuit state when the judgment result of the judgment module is no, calculate the first short-circuit current phase angle in the stationary coordinate system according to the three-phase current information of the permanent magnet synchronous motor in the short-circuit state, calculate the second short-circuit current phase angle in the rotating coordinate system according to the duration of the permanent magnet synchronous motor in the short-circuit state, obtain the second rotor position angle of the permanent magnet synchronous motor according to the difference between the second short-circuit current phase angle and the first short-circuit current phase angle, and use the second rotor position angle to perform the belt speed re-throw operation.

[0039] Another aspect of the present invention provides an electronic device, comprising:

[0040] Memory for storing computer programs;

[0041] A processor is used to implement the steps of the full-speed range belt speed re-investment method of the permanent magnet synchronous motor as described above when executing the computer program.

[0042] Another aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-mentioned full-speed range belt speed re-investment method of the permanent magnet synchronous motor.

[0043] The present invention has at least the following beneficial effects:

[0044] The present invention determines whether the back electromotive force of the permanent magnet synchronous motor is greater than the DC side bus voltage; if so, the isolation contactor of the permanent magnet synchronous motor is controlled to be closed, the three-phase bridge arm state information of the permanent magnet synchronous motor is determined according to the three-phase current information of the permanent magnet synchronous motor and the corresponding relationship table between the three-phase current and the three-phase bridge arm state, the three-phase voltage information of the permanent magnet synchronous motor is constructed according to the DC side bus voltage of the permanent magnet synchronous motor and the three-phase bridge arm state information, the first rotor position angle of the permanent magnet synchronous motor is calculated according to the three-phase voltage information, and the belt speed re-throw operation is performed using the first rotor position angle; if not, the permanent magnet synchronous motor is controlled to be in a short-circuit state, the first short-circuit current phase angle in a stationary coordinate system is calculated according to the three-phase current information of the permanent magnet synchronous motor in the short-circuit state, the second short-circuit current phase angle in a rotating coordinate system is calculated according to the duration of the permanent magnet synchronous motor in the short-circuit state, the second rotor position angle of the permanent magnet synchronous motor is obtained according to the difference between the second short-circuit current phase angle and the first short-circuit current phase angle, and the belt speed re-throw operation is performed using the second rotor position angle. By adopting the solution of the present application, it is possible to perform a belt speed re-throw operation in the full speed range of the permanent magnet synchronous motor, ensuring that the rotor position of the motor is accurately obtained under any working condition. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0046] Figure 1 A schematic flow chart of a method for re-starting a permanent magnet synchronous motor in full speed range provided by an embodiment of the present invention;

[0047] Figure 2 A schematic structural diagram of a full-speed range belt speed re-throw device for a permanent magnet synchronous motor provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0048] The core of the present invention is to provide a full-speed range speed re-throw method, device, equipment and medium for a permanent magnet synchronous motor, which can perform speed re-throw operations in the full-speed range of the permanent magnet synchronous motor to ensure that the rotor position of the motor is accurately obtained under any working conditions.

[0049] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0050] On the one hand, an embodiment of the present invention provides a full-speed range belt speed re-start method for a permanent magnet synchronous motor, please refer to Figure 1 , the method comprising:

[0051] Step S110, determine whether the back electromotive force of the permanent magnet synchronous motor is greater than the DC side bus voltage. If yes, execute step S120; if no, execute step S130.

[0052] In the embodiment of the present invention, the permanent magnet synchronous motor will generate a back electromotive force proportional to the speed on the stator when it is running. When the speed of the permanent magnet synchronous motor is high, the generated back electromotive force may be higher than the DC bus voltage. At this time, the current will be fed back from the permanent magnet synchronous motor into the DC bus capacitor, resulting in energy recharge. Therefore, it is necessary to first determine whether there is energy recharge in the permanent magnet synchronous motor, and perform different belt speed re-throw operations according to the determination result.

[0053] Step S120, control the isolation contactor of the permanent magnet synchronous motor to close, determine the three-phase bridge arm state information of the permanent magnet synchronous motor according to the three-phase current information of the permanent magnet synchronous motor and the correspondence table between the three-phase current and the three-phase bridge arm state, construct the three-phase voltage information of the permanent magnet synchronous motor according to the DC side bus voltage of the permanent magnet synchronous motor and the three-phase bridge arm state information, calculate the first rotor position angle of the permanent magnet synchronous motor according to the three-phase voltage information, and use the first rotor position angle to perform the belt speed re-throw operation.

[0054] In an embodiment of the present invention, if the back electromotive force of the permanent magnet synchronous motor is greater than the DC side bus voltage, the isolation contactor of the permanent magnet synchronous motor is controlled to close, and the three-phase bridge arm state information of the permanent magnet synchronous motor is determined according to the three-phase current information of the permanent magnet synchronous motor and the correspondence table between the three-phase current and the three-phase bridge arm state. Among them, the three-phase current information of the permanent magnet synchronous motor can be obtained through a current sensor, and the correspondence table between the three-phase current and the three-phase bridge arm state can be calibrated in advance through a conduction test of the isolation contactor. Then, according to the DC side bus voltage and the three-phase bridge arm state information, the three-phase voltage information of the permanent magnet synchronous motor under various conditions can be constructed. Among them, the DC side bus voltage can be obtained through an intermediate voltage sensor. Finally, the first rotor position angle of the permanent magnet synchronous motor can be calculated according to the three-phase voltage information, and then the first rotor position angle is used to perform the belt speed re-throw operation.

[0055] It should be noted that if the back electromotive force of the permanent magnet synchronous motor is greater than the DC side bus voltage, that is, there is energy recharge in the permanent magnet synchronous motor, since it is in a zero initial state with current at this time, using the short-circuit current method to estimate the position of the rotor will result in excessive deviation, and it is easy to cause overcurrent during the speed re-throw process. Therefore, the speed re-throw operation is generally directly prohibited in the prior art. In the embodiment of the present invention, according to the three-phase current information of the permanent magnet synchronous motor and the pre-constructed correspondence table between the three-phase current and the three-phase bridge arm state, the three-phase voltage information of the permanent magnet synchronous motor under various conditions can be constructed, and the first rotor position angle of the permanent magnet synchronous motor can be accurately calculated according to the three-phase voltage information, so that the speed re-throw operation can still be performed when the permanent magnet synchronous motor is running at high speed.

[0056] Step S130, control the permanent magnet synchronous motor to be in a short-circuit state, calculate the first short-circuit current phase angle in the stationary coordinate system according to the three-phase current information of the permanent magnet synchronous motor in the short-circuit state, calculate the second short-circuit current phase angle in the rotating coordinate system according to the duration of the permanent magnet synchronous motor in the short-circuit state, obtain the second rotor position angle of the permanent magnet synchronous motor according to the difference between the second short-circuit current phase angle and the first short-circuit current phase angle, and use the second rotor position angle to perform the belt speed re-throw operation.

[0057] In an embodiment of the present invention, if the back electromotive force of the permanent magnet synchronous motor is less than or equal to the DC side bus voltage, that is, there is no energy recirculation in the permanent magnet synchronous motor, then it is in a three-phase zero initial state, and the short-circuit current method can be used to estimate the position of the rotor, and then perform a speed re-throw operation.

[0058] As can be seen from the above, the full-speed range speed re-investment method of the permanent magnet synchronous motor provided by the embodiment of the present invention determines whether the back electromotive force of the permanent magnet synchronous motor is greater than the DC side bus voltage; if so, the isolation contactor of the permanent magnet synchronous motor is controlled to close, and the three-phase bridge arm state information of the permanent magnet synchronous motor is determined according to the three-phase current information of the permanent magnet synchronous motor and the correspondence table between the three-phase current and the three-phase bridge arm state, and the three-phase voltage information of the permanent magnet synchronous motor is constructed according to the DC side bus voltage of the permanent magnet synchronous motor and the three-phase bridge arm state information, and the permanent magnet is calculated according to the three-phase voltage information. The first rotor position angle of the synchronous motor is determined, and the first rotor position angle is used to perform the belt speed re-throw operation; if not, the permanent magnet synchronous motor is controlled to be in a short-circuit state, and the first short-circuit current phase angle in the stationary coordinate system is calculated according to the three-phase current information of the permanent magnet synchronous motor in the short-circuit state, and the second short-circuit current phase angle in the rotating coordinate system is calculated according to the duration of the permanent magnet synchronous motor in the short-circuit state, and the second rotor position angle of the permanent magnet synchronous motor is obtained according to the difference between the second short-circuit current phase angle and the first short-circuit current phase angle, and the belt speed re-throw operation is performed using the second rotor position angle. The solution of the present application can perform the belt speed re-throw operation in the full speed range of the permanent magnet synchronous motor, ensuring that the rotor position of the motor is accurately obtained under any working condition.

[0059] Optionally, in the above embodiment, the correspondence table between the three-phase current and the three-phase bridge arm state is calibrated in the following manner:

[0060] During the duration of the isolating contactor performing the closing action, the three-phase current sampling information and the three-phase bridge arm state sampling information of the permanent magnet synchronous motor are periodically recorded to obtain a corresponding relationship table between the three-phase current and the three-phase bridge arm state.

[0061] In the embodiment of the present invention, although there are many types of isolation contactors for permanent magnet synchronous motors, including three-pole independent isolation contactors, three-pole linkage isolation contactors, vacuum isolation contactors, etc., they are all mechanical devices, and there are multiple combination types, and the three-phase closing time cannot be completely consistent. Taking the three-pole independent isolation contactor as an example, the three contactors have their own action devices, resulting in differences in the three-phase closing time, and the three-phase closing order is random, which is reflected externally as a three-phase closing delay, and the delay specification is generally 5ms-10ms. Therefore, it is necessary to conduct a conduction test on the isolation contactor of the permanent magnet synchronous motor in advance to determine the corresponding three-phase current information under different conduction sequences and conduction time combinations of the three contactors.

[0062] Specifically, in the process of the isolation contactor performing the closing action, the three-phase current sampling information and the three-phase bridge arm state sampling information of the permanent magnet synchronous motor are periodically recorded. For example, the three-phase current sampling information and the three-phase bridge arm state sampling information are recorded once every 0.1ms, and multiple groups of three-phase current sampling values ​​and three-phase bridge arm state sampling values ​​can be obtained within the total time of the isolation contactor performing the closing action; in addition, the three-phase closing order of the isolation contactor is random, so the isolation contactor can be subjected to multiple conduction tests, and finally the correspondence table between the three-phase current and the three-phase bridge arm state is obtained. It can be understood that the shorter the sampling period, the more sampling values ​​are obtained, the more accurate the calibrated correspondence table is, the more accurate the identification of the motor rotor position is, and the smaller the current impact when the belt speed is re-thrown.

[0063] For example, when all three contactors are not closed, the three-phase currents are all 0; when the A-phase and C-phase contactors are closed first and the B-phase contactor is closed with a delay, if the flow toward the permanent magnet synchronous motor is the positive direction, the A-phase current sampling value is negative, the C-phase current sampling value is positive, and the B-phase current sampling value is 0; when the B-phase and C-phase contactors are closed first and the A-phase contactor is closed with a delay, the B-phase current sampling value is negative, the C-phase current sampling value is positive, and the A-phase current sampling value is 0.

[0064] For example, the A-phase and C-phase contactors are closed first, and the B-phase contactor is closed later. At this time, the three-phase voltage is constructed as follows:

[0065] ;

[0066] in, u a , u b , u c Represent the voltage of phase A, phase B, and phase C respectively. E 0 represents the back EMF of the permanent magnet synchronous motor, U dc represents the DC bus voltage, T a and T c Respectively represent the time when phase A and phase C close first. It can be understood that T a and T c It can be calculated based on the sampling period and sampling time.

[0067] Furthermore, in the above embodiment, calculating the first rotor position angle of the permanent magnet synchronous motor according to the three-phase voltage information includes:

[0068] Calculate the direct-axis voltage and quadrature-axis voltage in a rotating coordinate system according to the three-phase voltage information and the circuit topology of the permanent magnet synchronous motor;

[0069] Calculate the direct-axis current and the quadrature-axis current in the rotating coordinate system according to the direct-axis voltage and the quadrature-axis voltage;

[0070] A first rotor position angle of the permanent magnet synchronous motor is calculated according to the direct-axis current and the quadrature-axis current.

[0071] Furthermore, in the above embodiment, the direct-axis current and the quadrature-axis current in the rotating coordinate system are calculated according to the direct-axis voltage and the quadrature-axis voltage, including:

[0072] The direct-axis current and quadrature-axis current in the rotating coordinate system are calculated using the following formula:

[0073] ;

[0074] in, u d and u q represent the direct-axis voltage and quadrature-axis voltage respectively, R represents the stator resistance, p represents the differential operator, L d and L q Represent the direct-axis inductance and quadrature-axis inductance respectively. oh e represents the electrical angular velocity, and represent the direct-axis current and quadrature-axis current respectively, P f represents the permanent magnet flux;

[0075] The first rotor position angle of the permanent magnet synchronous motor is calculated according to the direct axis current and the quadrature axis current, including:

[0076] The first rotor position angle of the permanent magnet synchronous motor is calculated by the following formula:

[0077] ;

[0078] in, Represents the first rotor position angle of the permanent magnet synchronous motor.

[0079] In the embodiment of the present invention, after constructing the three-phase voltage information, coordinate transformation is performed in combination with the circuit topology of the permanent magnet synchronous motor, and the direct-axis voltage and quadrature-axis voltage in the dq rotating coordinate system can be obtained. Then, according to the voltage equation of the permanent magnet synchronous motor in the dq rotating coordinate system, the direct-axis current and quadrature-axis current in the dq rotating coordinate system can be calculated. Finally, the first rotor position angle of the permanent magnet synchronous motor can be accurately calculated by the inverse tangent function.

[0080] Optionally, in the above embodiment, calculating the first short-circuit current phase angle in the stationary coordinate system according to the three-phase current information of the permanent magnet synchronous motor in the short-circuit state includes:

[0081] The first short-circuit current phase angle is calculated by the following formula:

[0082] ;

[0083] in, represents the first short-circuit current phase angle, and Represents the current components of the three-phase current of the permanent magnet synchronous motor in the short-circuit state in the stationary coordinate system.

[0084] Furthermore, in the above embodiment, calculating the second short-circuit current phase angle in the rotating coordinate system according to the duration of the permanent magnet synchronous motor being in the short-circuit state includes:

[0085] The second short-circuit current phase angle is calculated by the following formula:

[0086] ;

[0087] in, represents the second short-circuit current phase angle, and represents the current component in the rotating coordinate system, and Represent the direct-axis inductance and quadrature-axis inductance respectively. represents the electrical angular velocity, represents the permanent magnet flux, T Represents the duration that the permanent magnet synchronous motor is in a short-circuit state.

[0088] In the embodiment of the present invention, if the back electromotive force of the permanent magnet synchronous motor is less than or equal to the DC bus voltage, that is, there is no energy recirculation in the permanent magnet synchronous motor, the short-circuit current method can be used to estimate the rotor position.

[0089] First, a zero voltage vector is sent to the inverter to turn on all the upper or lower arm switches of the converter, so that the permanent magnet synchronous motor is in a three-phase short-circuit state and maintains this state continuously. Ttime.

[0090] Then, the three-phase current of the permanent magnet synchronous motor in the short-circuit state i Decompose into Current components in the stationary coordinate system and ,definition for i exist The first short-circuit current phase angle in the stationary coordinate system is:

[0091] ;

[0092] When the stator resistance is ignored and all the upper arm switches or lower arm switches of the converter are turned on, the permanent magnet synchronous motor is in a short-circuited state and its terminal voltage is zero. At this time, the voltage equation of the permanent magnet synchronous motor in the dq rotating coordinate system is:

[0093] ;

[0094] Assumptions oh e is a constant, the initial current is zero, and Laplace transform is performed on the above formula to obtain:

[0095] ;

[0096] definition for i The second short-circuit current phase angle in the dq rotating coordinate system is:

[0097] ;

[0098] Finally, the second rotor position angle of the permanent magnet synchronous motor can be obtained according to the difference between the second short-circuit current phase angle and the first short-circuit current phase angle, that is:

[0099] ;

[0100] in, Represents the second rotor position angle.

[0101] Specifically, in the above embodiment, the back electromotive force of the permanent magnet synchronous motor is calculated by the following formula:

[0102] ;

[0103] in, represents the back EMF of the permanent magnet synchronous motor, represents the electrical angular velocity, Represents the permanent magnet flux.

[0104] In the embodiment of the present invention, the electrical angular velocity of the permanent magnet synchronous motor can be obtained according to the system trailer speed. oh e , and then calculate the back EMF of the permanent magnet synchronous motor E 0 .

[0105] Another aspect of an embodiment of the present invention provides a full-speed range belt speed re-throw device for a permanent magnet synchronous motor. The device described below can be referred to in correspondence with the method described above.

[0106] See also Figure 2 , the device comprises:

[0107] A judgment module 210 is used to judge whether the back electromotive force of the permanent magnet synchronous motor is greater than the DC side bus voltage;

[0108] The first execution module 220 is used to control the isolation contactor of the permanent magnet synchronous motor to close when the determination result of the judgment module is yes, determine the three-phase bridge arm state information of the permanent magnet synchronous motor according to the three-phase current information of the permanent magnet synchronous motor and the correspondence table between the three-phase current and the three-phase bridge arm state, construct the three-phase voltage information of the permanent magnet synchronous motor according to the DC side bus voltage of the permanent magnet synchronous motor and the three-phase bridge arm state information, calculate the first rotor position angle of the permanent magnet synchronous motor according to the three-phase voltage information, and perform the belt speed re-throw operation using the first rotor position angle;

[0109] The second execution module 230 is used to control the permanent magnet synchronous motor to be in a short-circuit state when the judgment result of the judgment module is no, calculate the first short-circuit current phase angle in the stationary coordinate system according to the three-phase current information of the permanent magnet synchronous motor in the short-circuit state, calculate the second short-circuit current phase angle in the rotating coordinate system according to the duration of the permanent magnet synchronous motor in the short-circuit state, obtain the second rotor position angle of the permanent magnet synchronous motor according to the difference between the second short-circuit current phase angle and the first short-circuit current phase angle, and use the second rotor position angle to perform the belt speed re-throw operation.

[0110] As can be seen from the above, the full-speed range speed re-throw device of the permanent magnet synchronous motor provided by the embodiment of the present invention determines whether the back electromotive force of the permanent magnet synchronous motor is greater than the DC side bus voltage; if so, the isolation contactor of the permanent magnet synchronous motor is controlled to close, and the three-phase bridge arm state information of the permanent magnet synchronous motor is determined according to the three-phase current information of the permanent magnet synchronous motor and the correspondence table between the three-phase current and the three-phase bridge arm state, and the three-phase voltage information of the permanent magnet synchronous motor is constructed according to the DC side bus voltage of the permanent magnet synchronous motor and the three-phase bridge arm state information, and the permanent magnet is calculated according to the three-phase voltage information. The first rotor position angle of the synchronous motor is determined, and the first rotor position angle is used to perform the belt speed re-throw operation; if not, the permanent magnet synchronous motor is controlled to be in a short-circuit state, and the first short-circuit current phase angle in the stationary coordinate system is calculated according to the three-phase current information of the permanent magnet synchronous motor in the short-circuit state, and the second short-circuit current phase angle in the rotating coordinate system is calculated according to the duration of the permanent magnet synchronous motor in the short-circuit state, and the second rotor position angle of the permanent magnet synchronous motor is obtained according to the difference between the second short-circuit current phase angle and the first short-circuit current phase angle, and the belt speed re-throw operation is performed using the second rotor position angle. The solution of the present application can perform the belt speed re-throw operation in the full speed range of the permanent magnet synchronous motor, ensuring that the rotor position of the motor is accurately obtained under any working condition.

[0111] Another aspect of an embodiment of the present invention provides an electronic device, including:

[0112] Memory for storing computer programs;

[0113] A processor is used to implement the steps of the full-speed range belt speed re-investment method of the permanent magnet synchronous motor as described above when executing the computer program.

[0114] Another aspect of an embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-mentioned full-speed range belt speed re-investment method of a permanent magnet synchronous motor.

[0115] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the embodiments can be referred to each other. It should also be noted that in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only those elements, but also other elements that are not explicitly listed, or also include elements inherent to such process, method, article or equipment. In the absence of more restrictions, the elements defined by the sentence "including one..." do not exclude the existence of other identical elements in the process, method, article or equipment including the element.

[0116] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A full-speed range belt speed re-start method for a permanent magnet synchronous motor, It is characterized in that include: Determine whether the back electromotive force of the permanent magnet synchronous motor is greater than the DC side bus voltage; If so, control the isolation contactor of the permanent magnet synchronous motor to close, determine the three-phase bridge arm state information of the permanent magnet synchronous motor according to the three-phase current information of the permanent magnet synchronous motor and the correspondence table between the three-phase current and the three-phase bridge arm state, construct the three-phase voltage information of the permanent magnet synchronous motor according to the DC side bus voltage of the permanent magnet synchronous motor and the three-phase bridge arm state information, calculate the first rotor position angle of the permanent magnet synchronous motor according to the three-phase voltage information, and perform the belt speed re-throw operation using the first rotor position angle; If not, the permanent magnet synchronous motor is controlled to be in a short-circuit state, a first short-circuit current phase angle in a stationary coordinate system is calculated according to the three-phase current information of the permanent magnet synchronous motor in the short-circuit state, a second short-circuit current phase angle in a rotating coordinate system is calculated according to the duration of the permanent magnet synchronous motor in the short-circuit state, a second rotor position angle of the permanent magnet synchronous motor is obtained according to the difference between the second short-circuit current phase angle and the first short-circuit current phase angle, and the second rotor position angle is used to perform a belt speed re-throw operation.

2. The full-speed range belt speed re-start method of the permanent magnet synchronous motor according to claim 1, It is characterized in that The correspondence table between the three-phase current and the three-phase bridge arm state is calibrated in the following manner: During the duration of the isolation contactor performing the closing action, the three-phase current sampling information of the permanent magnet synchronous motor and the three-phase bridge arm state sampling information are periodically recorded to obtain a correspondence table between the three-phase current and the three-phase bridge arm state.

3. The full-speed range belt speed re-start method of the permanent magnet synchronous motor according to claim 1, It is characterized in that The step of calculating the first rotor position angle of the permanent magnet synchronous motor according to the three-phase voltage information comprises: Calculating a direct-axis voltage and a quadrature-axis voltage in a rotating coordinate system according to the three-phase voltage information and a circuit topology structure of the permanent magnet synchronous motor; Calculating a direct-axis current and a quadrature-axis current in a rotating coordinate system according to the direct-axis voltage and the quadrature-axis voltage; A first rotor position angle of the permanent magnet synchronous motor is calculated according to the direct-axis current and the quadrature-axis current.

4. The full-speed range belt speed re-start method of the permanent magnet synchronous motor according to claim 3, It is characterized in that The calculating the direct-axis current and the quadrature-axis current in the rotating coordinate system according to the direct-axis voltage and the quadrature-axis voltage comprises: The direct-axis current and quadrature-axis current in the rotating coordinate system are calculated using the following formula: ； in, u d and u q represent the direct-axis voltage and the quadrature-axis voltage respectively, R represents the stator resistance, p represents the differential operator, L d and L q Represent the direct-axis inductance and quadrature-axis inductance respectively. ω e represents the electrical angular velocity, and represent the direct-axis current and the quadrature-axis current respectively, Ψ f represents the permanent magnet flux; The step of calculating a first rotor position angle of the permanent magnet synchronous motor according to the direct-axis current and the quadrature-axis current comprises: The first rotor position angle of the permanent magnet synchronous motor is calculated by the following formula: ； in, represents a first rotor position angle of the permanent magnet synchronous motor.

5. The full-speed range belt speed re-start method of the permanent magnet synchronous motor according to claim 1, It is characterized in that The method of calculating a first short-circuit current phase angle in a stationary coordinate system according to three-phase current information of the permanent magnet synchronous motor in a short-circuit state includes: The first short-circuit current phase angle is calculated by the following formula: ； in, represents the first short-circuit current phase angle, and The current component representing the three-phase current of the permanent magnet synchronous motor in a short-circuit state in a stationary coordinate system.

6. The full-speed range belt speed re-start method of the permanent magnet synchronous motor according to claim 5, It is characterized in that The step of calculating a second short-circuit current phase angle in a rotating coordinate system according to the duration that the permanent magnet synchronous motor is in a short-circuit state comprises: The second short-circuit current phase angle is calculated by the following formula: ； in, represents the second short-circuit current phase angle, and represents the current component in the rotating coordinate system, and Represent the direct-axis inductance and quadrature-axis inductance respectively. represents the electrical angular velocity, represents the permanent magnet flux, T Represents the duration that the permanent magnet synchronous motor is in a short-circuit state.

7. The full-speed range belt speed re-start method of the permanent magnet synchronous motor according to claim 1, It is characterized in that The back electromotive force of the permanent magnet synchronous motor is calculated by the following formula: ； in, represents the back EMF of the permanent magnet synchronous motor, represents the electrical angular velocity, Represents the permanent magnet flux.

8. A full-speed range belt speed re-throw device for a permanent magnet synchronous motor, It is characterized in that include: A judgment module, used to judge whether the back electromotive force of the permanent magnet synchronous motor is greater than the DC side bus voltage; a first execution module, for controlling the isolation contactor of the permanent magnet synchronous motor to close when the determination result of the determination module is yes, determining the three-phase bridge arm state information of the permanent magnet synchronous motor according to the three-phase current information of the permanent magnet synchronous motor and a correspondence table between the three-phase current and the three-phase bridge arm state, constructing the three-phase voltage information of the permanent magnet synchronous motor according to the DC side bus voltage of the permanent magnet synchronous motor and the three-phase bridge arm state information, calculating the first rotor position angle of the permanent magnet synchronous motor according to the three-phase voltage information, and performing the belt speed re-throw operation using the first rotor position angle; The second execution module is used to control the permanent magnet synchronous motor to be in a short-circuit state when the judgment result of the judgment module is no, calculate the first short-circuit current phase angle in the stationary coordinate system according to the three-phase current information of the permanent magnet synchronous motor in the short-circuit state, calculate the second short-circuit current phase angle in the rotating coordinate system according to the duration of the permanent magnet synchronous motor in the short-circuit state, obtain the second rotor position angle of the permanent magnet synchronous motor according to the difference between the second short-circuit current phase angle and the first short-circuit current phase angle, and use the second rotor position angle to perform the belt speed re-throw operation.

9. An electronic device, It is characterized in that include: Memory for storing computer programs; A processor, for implementing the steps of the full-speed range belt speed re-investment method of the permanent magnet synchronous motor as described in any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium, It is characterized in that The computer-readable storage medium stores a computer program, and when the computer program is executed by the processor, the steps of the full-speed range belt speed re-investment method of the permanent magnet synchronous motor as described in any one of claims 1 to 7 are implemented.

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