Motor flywheel starting method and device, frequency converter and computer readable storage medium

Abstract

The application discloses a motor flywheel starting method and device, a frequency converter and a computer readable storage medium, wherein the method comprises the following steps: acquiring three-phase counter electromotive force of a motor, determining line electromotive force of the motor according to the three-phase counter electromotive force; performing coordinate conversion on the line electromotive force of the motor to obtain d-axis voltage and q-axis voltage; determining line counter electromotive force module value of the motor according to the d-axis voltage and the q-axis voltage, and performing phase-locked loop processing on the q-axis voltage to obtain the running frequency of the motor and the line counter electromotive force phase angle; determining phase voltage module value and phase voltage phase angle of the motor according to the line counter electromotive force module value and the line counter electromotive force phase angle of the motor, and controlling the motor to perform flywheel starting according to the running frequency, the phase voltage module value and the phase voltage phase angle of the motor. Thus, the method determines the running frequency, the phase voltage module value and the phase voltage phase angle of the motor through coordinate conversion and phase-locked loop processing on the line electromotive force of the motor, effectively improves the input signal quality, and realizes accurate phase locking under high noise.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of motor starting, in particular to a motor flywheel starting method, a frequency converter, a computer readable storage medium and a motor flywheel starting device. BACKGROUND

[0002] Flywheel starting refers to starting the motor by the frequency converter when the motor is still rotating, which can minimize the motor speed drop and reduce the impact of shutdown on the system. However, in the case of motor rotation and residual magnetism of the motor, the motor will generate back electromotive force, and at this time, directly starting the motor will generate a large impact current, damaging the frequency converter.

[0003] In the related art, the motor flywheel starting adopts a software phase-locked control method, which can effectively reduce the starting impact current and even realize non-impact forward and reverse starting. When the motor speed is high, the back electromotive force is also high, and the phase-locked loop can achieve fast and accurate phase locking. However, when the motor speed is low, for example, the motor operating frequency is lower than 5Hz, or when the motor speed is very high but the motor has been rotating for a long time, resulting in low rotor residual magnetism, the motor output back electromotive force will be low, or even submerged in noise, at this time, the phase-locked loop cannot be stably locked, causing the phase-locked loop output signal to jump or the output signal to deviate greatly from the normal value. With such an output signal to control the flywheel starting, it is easy to produce an impact current, which will cause harm to the motor and the frequency converter. SUMMARY

[0004] The present application aims to at least solve one of the technical problems in the related art. To this end, one object of the present application is to provide a motor flywheel starting method, which determines the motor operating frequency, phase voltage modulus and phase voltage phase angle by coordinate transformation and phase-locked loop processing of the motor line voltage, effectively improves the input signal quality, and realizes accurate phase locking under high noise conditions.

[0005] A second object of the present application is to provide a frequency converter.

[0006] A third object of the present application is to provide a computer readable storage medium.

[0007] A fourth object of the present application is to provide a motor flywheel starting device.

[0008] To achieve the above object, the embodiment of the first aspect of the present application provides a motor flywheel starting method, comprising: obtaining three-phase counter electromotive force of the motor, and determining line electromotive force of the motor according to the three-phase counter electromotive force; performing coordinate conversion on the line electromotive force of the motor to obtain d-axis voltage and q-axis voltage; determining line counter electromotive force module value of the motor according to the d-axis voltage and the q-axis voltage, and performing phase-locked loop processing on the q-axis voltage to obtain operating frequency and line counter electromotive force phase angle of the motor; determining phase voltage module value and phase voltage phase angle of the motor according to the line counter electromotive force module value and the line counter electromotive force phase angle of the motor, and controlling the motor to flywheel start according to the operating frequency, the phase voltage module value and the phase voltage phase angle of the motor.

[0009] The motor flywheel starting method according to the embodiment of the present application firstly obtains three-phase counter electromotive force of the motor, and determines line electromotive force of the motor according to the three-phase counter electromotive force, and performs coordinate conversion on the line electromotive force of the motor to obtain d-axis voltage and q-axis voltage, then, determines line counter electromotive force module value of the motor according to the d-axis voltage and the q-axis voltage, and performs phase-locked loop processing on the q-axis voltage to obtain operating frequency and line counter electromotive force phase angle of the motor, finally, determines phase voltage module value and phase voltage phase angle of the motor according to the line counter electromotive force module value and the line counter electromotive force phase angle of the motor, and controls the motor to flywheel start according to the operating frequency, the phase voltage module value and the phase voltage phase angle of the motor. Thus, the method determines the operating frequency, the phase voltage module value and the phase voltage phase angle of the motor through coordinate transformation and phase-locked loop processing on the line electromotive force of the motor, effectively improves input signal quality, and realizes accurate phase locking under high noise condition.

[0010] In addition, the motor flywheel starting method according to the above embodiment of the present application can have the following additional technical features:

[0011] According to one embodiment of the present application, before performing phase-locked loop processing on the q-axis voltage, the method further comprises: performing adaptive amplification processing on the q-axis voltage according to the line counter electromotive force module value of the motor.

[0012] According to one embodiment of the present application, the phase-locked loop processing on the q-axis voltage comprises: determining voltage difference between the q-axis voltage after adaptive amplification processing and given q-axis voltage; performing PI (Proportional-Integral) adjustment on the voltage difference to obtain operating frequency of the motor; and performing integral processing on the angular frequency after PI adjustment to obtain the line counter electromotive force phase angle.

[0013] According to one embodiment of the present application, the q-axis voltage after adaptive amplification processing is determined according to the following formula:

[0014] U qq =U q / Emod

[0015] wherein, Uqq Uq is the q-axis voltage after adaptive amplification processing q Uq is the q-axis voltage, and Emod is the line back EMF module value.

[0016] According to one embodiment of the present application, the given q-axis voltage is zero.

[0017] According to one embodiment of the present application, the line voltage of the motor is subjected to coordinate conversion to obtain a d-axis voltage and a q-axis voltage, including: performing Clark transformation on the line voltage of the motor to convert from an abc coordinate system to an αβ coordinate system; and performing Park transformation on the voltage signal in the αβ coordinate system to obtain the d-axis voltage and the q-axis voltage in a dq coordinate system. According to one embodiment of the present application, the phase voltage module value and the phase voltage phase angle of the motor are determined according to the following formula:

[0018]

[0019] θd = θ - 30°

[0020] wherein Emodd is the phase voltage module value, Emod is the line back EMF module value, θd is the phase voltage phase angle, and θ is the line back EMF phase angle.

[0021] To achieve the above object, the second aspect embodiment of the present application provides a frequency converter, including a memory, a processor, and a motor flywheel starting program stored in the memory and executable on the processor. When the processor executes the motor flywheel starting program, the motor flywheel starting method described above is implemented.

[0022] According to the frequency converter of the embodiment of the present application, based on the motor flywheel starting method described above, the running frequency, the phase voltage module value, and the phase voltage phase angle of the motor are determined through coordinate conversion and phase-locked loop processing on the line voltage of the motor, effectively improving the input signal quality and realizing accurate phase locking under high noise conditions.

[0023] To achieve the above object, the third aspect embodiment of the present application provides a computer readable storage medium having a motor flywheel starting program stored thereon. The motor flywheel starting program is executable on a processor to implement the motor flywheel starting method described above.

[0024] According to the computer readable storage medium of the embodiment of the present application, based on the motor flywheel starting method described above, the running frequency, the phase voltage module value, and the phase voltage phase angle of the motor are determined through coordinate conversion and phase-locked loop processing on the line voltage of the motor, effectively improving the input signal quality and realizing accurate phase locking under high noise conditions.

[0025] To achieve the above object, the fourth aspect of the present application provides a motor flywheel starting device, comprising: an acquisition module configured to acquire three-phase counter electromotive force of the motor; a signal processing module configured to determine line potential of the motor according to the three-phase counter electromotive force; a coordinate transformation module configured to perform coordinate conversion on the line potential of the motor to obtain d-axis voltage and q-axis voltage; a module value calculation module configured to determine line counter electromotive force module value of the motor according to the d-axis voltage and the q-axis voltage; a phase-locked loop module configured to perform phase-locked loop processing on the q-axis voltage to obtain operating frequency and line counter electromotive force phase angle of the motor; a signal output module configured to determine phase voltage module value and phase voltage phase angle of the motor according to the line counter electromotive force module value and the line counter electromotive force phase angle of the motor; and a control module configured to control the motor to flywheel start according to the operating frequency, the phase voltage module value and the phase voltage phase angle of the motor.

[0026] According to the motor flywheel starting device provided by the embodiment of the present application, the three-phase counter electromotive force of the motor is acquired by the acquisition module, the line potential of the motor is determined according to the three-phase counter electromotive force by the signal processing module, the coordinate conversion is performed on the line potential of the motor by the coordinate transformation module to obtain the d-axis voltage and the q-axis voltage, the line counter electromotive force module value of the motor is determined according to the d-axis voltage and the q-axis voltage by the module value calculation module, the phase-locked loop processing is performed on the q-axis voltage by the phase-locked loop module to obtain the operating frequency and the line counter electromotive force phase angle of the motor, the phase voltage module value and the phase voltage phase angle of the motor are determined according to the line counter electromotive force module value and the line counter electromotive force phase angle of the motor by the signal output module, and the motor is controlled to flywheel start according to the operating frequency, the phase voltage module value and the phase voltage phase angle of the motor by the control module. Thus, the coordinate conversion and the phase-locked loop processing are performed on the line potential of the motor, the operating frequency, the phase voltage module value and the phase voltage phase angle of the motor are determined, the input signal quality is effectively improved, and the precise phase-locked loop under the high noise condition is realized.

[0027] In addition, the motor flywheel starting device according to the above-mentioned embodiments of the present application can have the following additional technical features:

[0028] According to an embodiment of the present application, the motor flywheel starting device further comprises an adaptive amplification module configured to perform adaptive amplification processing on the q-axis voltage according to the line counter electromotive force module value of the motor before the phase-locked loop processing on the q-axis voltage.

[0029] According to an embodiment of the present application, the phase-locked loop module performs the phase-locked loop processing on the q-axis voltage, specifically configured to: determine voltage difference between the q-axis voltage after the adaptive amplification processing and q-axis given voltage; perform PI adjustment on the voltage difference to obtain the operating frequency of the motor; and perform integral processing on the angular frequency after the PI adjustment to obtain the line counter electromotive force phase angle.

[0030] According to an embodiment of the present application, the adaptive amplification module determines the q-axis voltage after the adaptive amplification processing according to the following formula:

[0031] U qq = U q / Emod

[0032] wherein, U qq is the q-axis voltage after adaptive amplification processing, U q is the q-axis voltage, and Emod is the line counter electromotive force modulus.

[0033] According to an embodiment of the present application, the coordinate transformation module performs coordinate conversion on the line electromotive force of the motor to obtain the d-axis voltage and the q-axis voltage, comprising: performing Clark transformation on the line electromotive force of the motor to convert from the abc coordinate system to the αβ coordinate system; performing Park transformation on the voltage signal in the αβ coordinate system to obtain the d-axis voltage and the q-axis voltage in the dq coordinate system. According to an embodiment of the present application, the signal output module determines the phase voltage modulus and the phase voltage phase angle of the motor according to the following formula:

[0034]

[0035] θd = θ - 30°

[0036] wherein, Emodd is the phase voltage modulus, Emod is the line counter electromotive force modulus, and θd is the phase voltage phase angle, and θ is the line counter electromotive force phase angle.

[0037] Additional aspects and advantages of the present application will be made apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 is a flow chart of the motor flywheel starting method according to an embodiment of the present application;

[0039] Figure 2 is a circuit schematic diagram of the motor three-phase counter electromotive force according to an embodiment of the present application;

[0040] Figure 3 is a control block diagram of the motor flywheel starting method according to an embodiment of the present application;

[0041] Figure 4 is a block schematic diagram of the frequency converter according to an embodiment of the present application;

[0042] Figure 5 is a block schematic diagram of the motor flywheel starting device according to an embodiment of the present application. DETAILED DESCRIPTION

[0043] Embodiments of the present application are described below in detail with reference to the accompanying drawings, wherein like or similar elements are denoted by like or similar reference signs throughout the drawings. The embodiments described below are exemplary and are intended to explain the present application, and are not to be understood as limiting the present application.

[0044] The motor flywheel starting method, frequency converter, computer readable storage medium and motor flywheel starting device according to the embodiments of the present application are described below with reference to the accompanying drawings.

[0045] Figure 1 The flow chart of the motor flywheel starting method according to the embodiments of the present application.

[0046] As shown in Figure 1 , the motor flywheel starting method according to the embodiments of the present application can include the following steps:

[0047] S1, obtaining three-phase counter electromotive force of the motor, and determining line potential of the motor according to the three-phase counter electromotive force.

[0048] Specifically, first, the three-phase counter electromotive force of the motor is obtained by AD (Analogue-to-Digital conversion) sampling, and then the line potential of the motor is converted according to the corresponding calculation formula. For example, when the motor adopts Y connection, that is, the tail ends of the three-phase windings in the motor are connected together. As shown in Figure 2 , the actual three-phase voltage of the motor is U a0 , U b0 , U c0 , U n is a system noise signal, the three-phase counter electromotive force U a = U a0 + U n , U b = U b0 + U n , U c = U c0 + U n , thus it can be known that the three-phase counter electromotive force (U a , U b , U c ) of the Y-shaped three-phase system and the line potential (U ab , U bc , U ca ) have the following relationship:

[0049]

[0050]

[0051]

[0052] In other words, by collecting the three back electromotive forces U of the motor a U b U c The linear electromotive force U of the motor is calculated according to formulas (1), (2) and (3). ab U bc U ca Therefore, the linear electromotive force U of the motor ab U bc U ca The system noise signal U was eliminated. n At the same time, the voltage magnitude of the line potential is greater than that of the original three-phase voltage U of the motor. a0 U b0 U c0 The voltage magnitude has increased This increases the input signal-to-noise ratio by a factor of two.

[0053] It is understandable that the above relationship between the line potential and the three-phase voltage of the motor is the relationship when the motor is connected in a Y configuration. When the motor is connected in a delta configuration, the relationship between the line potential and the three-phase voltage will also change. It can be derived using a similar method, which will not be elaborated here.

[0054] The following describes the fly car starting method of this invention in detail, taking the motor with a Y-shaped connection as an example.

[0055] S2, perform coordinate transformation on the motor's line potential to obtain the d-axis voltage U. d and q-axis voltage U q .

[0056] According to one embodiment of the present invention, coordinate transformation is performed on the line potential of the motor to obtain the d-axis voltage and q-axis voltage, including: performing a Clark transformation on the line potential of the motor to convert it from the abc coordinate system to the αβ coordinate system; and performing a Park transformation on the voltage signal in the αβ coordinate system to obtain the d-axis voltage and q-axis voltage in the dq coordinate system.

[0057] Specifically, such as Figure 3 As shown, the obtained linear potential U is first expressed using formula (4). ab U bc U ca Perform a static coordinate transformation, i.e., the Clark transformation, to calculate U. α U β The calculation formula is as follows:

[0058]

[0059] Then, U is processed using formula (5). α, U β The d-axis voltage U d and the q-axis voltage U q are obtained by performing a rotation coordinate transformation, i.e. a Park transformation.

[0060]

[0061] It should be noted that ωt in formula (5) is the line back EMF phase angle θ, which can be obtained by sampling.

[0062] S3, the line back EMF modulus Emod of the motor is determined according to the d-axis voltage U d and the q-axis voltage U q , and the q-axis voltage U q is processed by a phase-locked loop to obtain the operating frequency f and the line back EMF phase angle θ of the motor.

[0063] That is, the line back EMF modulus Emod of the motor is calculated by substituting the d-axis voltage U d and the q-axis voltage U q into formula , and the q-axis voltage U q is processed by a phase-locked loop to obtain the operating frequency f and the line back EMF phase angle θ of the motor.

[0064] Further, as shown in Figure 3 , the line back EMF phase angle θ obtained by the phase-locked loop processing is fed back into the rotation coordinate transformation, so that the d-axis voltage U α and the q-axis voltage U β are transformed to obtain the d-axis voltage U d and the q-axis voltage U q .

[0065] According to one embodiment of the present application, before the q-axis voltage U q is processed by a phase-locked loop, the method further comprises: processing the q-axis voltage U q by adaptive amplification according to the line back EMF modulus Emod of the motor.

[0066] That is, the size of the current line back EMF is determined according to the line back EMF modulus Emod of the motor, and the size of the q-axis voltage U q for phase-locked loop processing is adjusted accordingly, so as to realize accurate phase locking. For example, a line back EMF modulus threshold value can be set, and according to the size difference between the line back EMF modulus Emod of the motor and the line back EMF modulus threshold value, a corresponding amplification coefficient is selected to amplify the q-axis voltage U q .

[0067] According to one embodiment of the present application, the q-axis voltage after adaptive amplification is determined according to the following formula:

[0068] U qq =U q / Emod (6)

[0069] Among them, U qq U is the q-axis voltage after adaptive amplification. q is the q-axis voltage, and Emod is the magnitude of the line back electromotive force.

[0070] Specifically, the q-axis voltage U q The q-axis voltage U is obtained through formula (6). q Adaptive amplification is performed to calculate the amplified q-axis voltage U. qq In other words, the q-axis voltage U q The amplification or reduction factor is related to the currently acquired line back EMF magnitude value Emod. When the line back EMF magnitude value Emod is less than 1, the input signal q-axis voltage U will be reduced. q To amplify the voltage, when the magnitude of the line back electromotive force Emod is greater than 1, then the q-axis voltage U... q To reduce its size.

[0071] According to one embodiment of the present invention, for the q-axis voltage U q Phase-locked loop (PLL) processing is performed, including: determining the q-axis voltage U after adaptive amplification. qq With q-axis given voltage U q * The voltage difference between the two is used to obtain the motor's operating frequency f by performing PI regulation on the voltage difference; the angular frequency ω after PI regulation is integrated to obtain the line back EMF phase angle θ.

[0072] According to one embodiment of the present invention, the q-axis given voltage U q * It is zero.

[0073] Specifically, the q-axis voltage U output after adaptive amplification processing using formula (6) qq With q-axis given voltage U q * The voltage difference between the two axes is input to a PI regulator, making the q-axis component zero, aligning the line potential with the d-axis, achieving phase-locked looping of the line potential, and calculating the operating frequency f of the output motor. In other words, the voltage U... qq With q-axis given voltage U q * The voltage difference between the two is input to a PI regulator. The PI regulator adjusts the voltage to obtain the angular frequency ω of the line potential. The operating frequency f of the motor is then calculated using the formula ω = 2πf. Finally, the angular frequency ω of the line potential obtained from the PI regulation is input to the integrator module, and the formula is used to calculate the operating frequency f of the motor. The phase angle θ of the line back electromotive force is calculated.

[0074] S4, determining the phase voltage modulus Emodd and the phase voltage phase angle θd of the motor according to the line counter electromotive force modulus Emod and the line counter electromotive force phase angle θ of the motor, and controlling the motor to start at a high speed according to the operating frequency f, the phase voltage modulus Emodd and the phase voltage phase angle θd of the motor.

[0075] According to one embodiment of the present application, the phase voltage modulus Emodd and the phase voltage phase angle θd of the motor are determined according to the following formula:

[0076]

[0077] θd = θ - 30°

[0078] Wherein, Emodd is the phase voltage modulus, Emod is the line counter electromotive force modulus, θd is the phase voltage phase angle, and θ is the line counter electromotive force phase angle.

[0079] Specifically, since the line counter electromotive force modulus Emod, the operating frequency f and the line counter electromotive force phase angle θ are obtained through the line electromotive force, the phase voltage parameters need to be obtained through transformation for the high-speed starting of the motor. According to the above formula (1), (2), (3), the voltage modulus and the phase angle relationship between the line electromotive force and the three-phase voltage can be obtained, and the above calculation formula (7) can be derived. The line counter electromotive force modulus Emod and the line counter electromotive force phase angle θ of the line electromotive force obtained through the above calculation are substituted into the calculation formula (7) to obtain the corresponding phase voltage modulus Emodd and the phase voltage phase angle θd of the motor, and the phase voltage frequency of the motor is the same as the line electromotive force frequency, so the obtained operating frequency f, the phase voltage modulus Emodd and the phase voltage phase angle θd of the motor are used for the control of the high-speed starting of the motor.

[0080] Further, the motor high-speed starting method of the embodiment of the present application collects the three-phase counter electromotive force U a , U b , U c of the motor through software algorithm to construct the line electromotive force U ab , U bc , U ca of the motor, which not only eliminates the system noise, but also improves the signal-to-noise ratio of the input signal in the subsequent motor high-speed starting method. Then, the line electromotive force U ab , U bc , U ca of the motor is sequentially subjected to the stationary coordinate transformation and the rotating coordinate transformation to calculate the d-axis voltage U d and the q-axis voltage U q , and the line counter electromotive force modulus Emod is determined according to the d-axis voltage U d and the q-axis voltage U q , and the q-axis voltage U qThe input PI regulator feedback channel is connected with the adaptive amplifier to form a software phase-locked loop to lock the line back electromotive force module value Emod of the motor, the running frequency f of the motor and the line back electromotive force phase angle θ. That is, the signal output by the phase-locked loop in the method is obtained according to the line electromotive force, and then the parameters obtained from the line electromotive force are restored to phase voltage parameters, and finally the running frequency f of the motor, the phase voltage module value Emodd and the phase voltage phase angle θd are obtained to control the motor to start at a high speed. Thus, the method adopts coordinate transformation, adaptive amplification and PI control to phase-lock the input signal to obtain the line back electromotive force module value of the motor, the running frequency of the motor and the line back electromotive force phase angle, and further realizes impact-free high-speed starting through parameter conversion, solves the problem of inaccurate phase-locked loop in the related art, effectively improves the input signal quality and realizes accurate phase locking under high noise. In addition, the software phase-locked loop technology is used for high-speed starting of the motor, and the running effect is good, impact-free starting can be realized, and compared with the hardware detection back electromotive force method in the related art, the method does not need to increase hardware cost, is suitable for a wide range of motor speeds, and can realize forward and reverse high-speed starting of the motor in a wide range of speeds.

[0081] In summary, according to the motor high-speed starting method of the embodiment of the application, the three-phase back electromotive force of the motor is first obtained, the line electromotive force of the motor is determined according to the three-phase back electromotive force, the d-axis voltage and the q-axis voltage are obtained through coordinate conversion of the line electromotive force of the motor, then the line back electromotive force module value of the motor is determined according to the d-axis voltage and the q-axis voltage, the running frequency and the line back electromotive force phase angle of the motor are obtained through phase-locked loop processing of the q-axis voltage, finally the phase voltage module value and the phase voltage phase angle of the motor are determined according to the line back electromotive force module value and the line back electromotive force phase angle of the motor, and the motor is controlled to start at a high speed according to the running frequency, the phase voltage module value and the phase voltage phase angle of the motor. Thus, the method determines the running frequency, the phase voltage module value and the phase voltage phase angle of the motor through coordinate transformation and phase-locked loop processing of the line electromotive force of the motor, effectively improves the input signal quality and realizes accurate phase locking under high noise.

[0082] Corresponding to the above embodiment, the application further provides a frequency converter.

[0083] As shown in Figure 4 the frequency converter 100 of the embodiment of the application includes a memory 110, a processor 120 and a motor high-speed starting program stored in the memory 110 and executable on the processor, and the motor high-speed starting program is executed by the processor 120 to implement the motor high-speed starting method described above.

[0084] For example, the processor 120 can be used to execute the method embodiment described above according to the instructions in the computer program.

[0085] In some embodiments of the present application, the processor 120 can include, but is not limited to:

[0086] A general processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic, a discrete hardware component, and the like.

[0087] In some embodiments of the present application, the memory 110 includes, but is not limited to:

[0088] A volatile memory and / or a non-volatile memory. The non-volatile memory can be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically EPROM (EEPROM), or a flash memory. The volatile memory can be a random access memory (RAM) used as an external cache. By way of example, and not limitation, many forms of RAM can be used, such as a static random access memory (SRAM), a dynamic random access memory (DRAM), a synchronous dynamic random access memory (SDRAM), a double data rate SDRAM (DDR SDRAM), an enhanced SDRAM (ESDRAM), a synch link DRAM (SLDRAM), and a direct Rambus RAM (DR RAM).

[0089] In some embodiments of the present application, the computer program can be divided into one or more modules, which are stored in the memory 110 and executed by the processor 120 to complete the method provided by the present application. The one or more modules can be a series of computer program instruction segments capable of completing a specific function, which are used to describe the execution process of the computer program in the frequency converter 100.

[0090] It should be understood that the various components of the frequency converter 100 are connected by a bus system, which includes, in addition to a data bus, a power bus, a control bus, and a status signal bus.

[0091] According to the frequency converter of the embodiment of the present application, based on the above motor flywheel starting method, the running frequency, the phase voltage modulus and the phase voltage phase angle of the motor are determined through the coordinate transformation and the phase-locked loop processing of the line potential of the motor, the input signal quality is effectively improved, and the accurate phase-locked loop is realized under the high noise condition.

[0092] Corresponding to the above embodiment, the present application further proposes a computer readable storage medium.

[0093] The computer readable storage medium of the embodiment of the present application has a motor flywheel starting program stored thereon, and the motor flywheel starting program is executed by the processor to realize the above motor flywheel starting method.

[0094] According to the computer readable storage medium of the embodiment of the present application, based on the above motor flywheel starting method, the running frequency, the phase voltage modulus and the phase voltage phase angle of the motor are determined through the coordinate transformation and the phase-locked loop processing of the line potential of the motor, the input signal quality is effectively improved, and the accurate phase-locked loop is realized under the high noise condition.

[0095] Corresponding to the above embodiment, the present application further proposes a motor flywheel starting device.

[0096] As shown in Figure 5 The motor flywheel starting device of the embodiment of the present application can include an acquisition module 10, a signal processing module 20, a coordinate transformation module 30, a modulus calculation module 40, a phase-locked loop module 50, a signal output module 60 and a control module 70.

[0097] The acquisition module 10 is used to acquire the three-phase counter electromotive force of the motor. The signal processing module 20 is used to determine the line potential of the motor according to the three-phase counter electromotive force. The coordinate transformation module 30 is used to perform coordinate conversion on the line potential of the motor to obtain the d-axis voltage and the q-axis voltage. The modulus calculation module 40 is used to determine the line counter electromotive force modulus of the motor according to the d-axis voltage and the q-axis voltage. The phase-locked loop module 50 is used to perform phase-locked loop processing on the q-axis voltage to obtain the running frequency and the line counter electromotive force phase angle of the motor. The signal output module 60 is used to determine the phase voltage modulus and the phase voltage phase angle of the motor according to the line counter electromotive force modulus and the line counter electromotive force phase angle of the motor. The control module 70 controls the motor to perform flywheel starting according to the running frequency, the phase voltage modulus and the phase voltage phase angle of the motor.

[0098] According to one embodiment of the present application, the motor flywheel starting device further comprises an adaptive amplification module, configured to perform adaptive amplification processing on the q-axis voltage according to the line back EMF module value before phase-locked loop processing is performed on the q-axis voltage.

[0099] According to one embodiment of the present application, the phase-locked loop module 50 performs phase-locked loop processing on the q-axis voltage, and specifically configured to: determine a voltage difference between the q-axis voltage after adaptive amplification processing and a given q-axis voltage; perform PI regulation on the voltage difference to obtain a running frequency of the motor; and perform integral processing on the angular frequency after PI regulation to obtain a line back EMF phase angle.

[0100] According to one embodiment of the present application, the adaptive amplification module determines the q-axis voltage after adaptive amplification processing according to the following formula:

[0101] Uqq=Uq / Emod

[0102] Wherein, Uqq is the q-axis voltage after adaptive amplification processing, Uq is the q-axis voltage, and Emod is the line back EMF module value.

[0103] According to one embodiment of the present application, the coordinate transformation module 30 performs coordinate conversion on the line voltage of the motor to obtain the d-axis voltage and the q-axis voltage, comprising: performing Clark transformation on the line voltage of the motor to convert from the abc coordinate system to the αβ coordinate system; and performing Park transformation on the voltage signal in the αβ coordinate system to obtain the d-axis voltage and the q-axis voltage in the dq coordinate system.

[0104] According to one embodiment of the present application, the signal output module 60 determines the phase voltage module value and the phase voltage phase angle of the motor according to the following formula:

[0105]

[0106] θd=θ-30°

[0107] Wherein, Emodd is the phase voltage module value, Emod is the line back EMF module value, θd is the phase voltage phase angle, and θ is the line back EMF phase angle.

[0108] It should be noted that the details of the motor flywheel starting device not disclosed in the embodiments of the present application are referred to the details disclosed in the motor flywheel starting method of the above-mentioned embodiments of the present application, and will not be repeated here.

[0109] The motor flywheel starting device according to the embodiment of the application obtains the three-phase counter electromotive force of the motor through the acquisition module, determines the line electromotive force of the motor according to the three-phase counter electromotive force through the signal processing module, performs coordinate conversion on the line electromotive force of the motor through the coordinate conversion module, obtains the d-axis voltage and the q-axis voltage, determines the line counter electromotive force module value of the motor according to the d-axis voltage and the q-axis voltage through the module value calculation module, performs phase-locked loop processing on the q-axis voltage through the phase-locked loop module, obtains the running frequency and the line counter electromotive force phase angle of the motor, and determines the phase voltage module value and the phase voltage phase angle of the motor according to the line counter electromotive force module value and the line counter electromotive force phase angle of the motor through the signal output module, and controls the motor to flywheel start according to the running frequency, the phase voltage module value and the phase voltage phase angle of the motor. Thus, the device determines the running frequency, the phase voltage module value and the phase voltage phase angle of the motor through coordinate conversion and phase-locked loop processing on the line electromotive force of the motor, effectively improves the input signal quality, and realizes accurate phase locking under high noise conditions.

[0110] It should be noted that the logic and / or steps represented in the flowcharts or otherwise described herein, for example, can be considered as a list of executable instructions for implementing logic functions, and can be embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor- based system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions, or in conjunction with such an instruction execution system, apparatus, or device. For the purposes of this specification, a "computer-readable medium" can be any apparatus that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of the computer-readable medium include the following: an electrical connection having one or more wires (electrical apparatus), a portable computer diskette (magnetic apparatus), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber (optical apparatus), and a portable compact disc read-only memory (CDROM). In addition, the computer-readable medium can even be paper or another suitable medium upon which the program is printed, because the program can be electronically obtained, for example, by optical scanning of the paper or other medium, followed by electronic

[0111] It should be understood that various parts of the present application can be implemented in hardware, software, firmware or a combination thereof. In the above embodiments, various steps or methods can be implemented in software or firmware that is stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, any of the following technologies, known in the art, or their combinations, can be used: discrete logic circuitry having logic gates for implementing logic functions on data signals, application specific integrated circuits having appropriate combinational logic gates, programmable gate arrays (PGA), field programmable gate arrays (FPGA), and the like.

[0112] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in one or more embodiments or examples.

[0113] In the present application, unless otherwise explicitly specified or limited in the embodiments, the terms "mounting", "connecting", "connecting" and "fixing" appearing in the embodiments should be understood broadly, for example, the connection can be fixed connection, or detachable connection, or integral, which can be understood, or mechanical connection, electrical connection, etc. Of course, it can also be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements, or the interaction relationship of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific implementation situation.

[0114] Although the embodiments of the present application have been shown and described above, it should be understood that the above embodiments are exemplary and cannot be understood as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. A method of electric machine flywheel starting, comprising: The method comprises the following steps: acquiring three-phase back electromotive force of the motor, and determining line electromotive force of the motor according to the three-phase back electromotive force to eliminate system noise signals; performing coordinate conversion on the line electromotive force of the motor to obtain d-axis voltage and q-axis voltage; determining line back electromotive force modulus of the motor according to the d-axis voltage and the q-axis voltage, and performing phase-locked loop processing on the q-axis voltage to obtain operating frequency and line back electromotive force phase angle of the motor; determining phase voltage modulus and phase voltage phase angle of the motor according to the line back electromotive force modulus and the line back electromotive force phase angle of the motor, and controlling the motor to perform flywheel starting according to the operating frequency, the phase voltage modulus and the phase voltage phase angle of the motor; the phase voltage modulus and the phase voltage phase angle of the motor are determined according to the following formula: θd=θ-30° wherein, Emodd is the phase voltage modulus, Emod is the line back electromotive force modulus, θd is the phase voltage phase angle, and θ is the line back electromotive force phase angle; before the phase-locked loop processing is performed on the q-axis voltage, the method further comprises the following steps: performing adaptive amplification processing on the q-axis voltage according to the line back electromotive force modulus of the motor; the phase-locked loop processing on the q-axis voltage comprises the following steps: determining voltage difference between the q-axis voltage after adaptive amplification processing and q-axis given voltage; performing PI regulation on the voltage difference to obtain the operating frequency of the motor; performing integral processing on the angular frequency after PI regulation to obtain the line back electromotive force phase angle; the q-axis voltage after adaptive amplification processing is determined according to the following formula: U qq = U q / Emod wherein U qq is the q-axis voltage after the adaptive amplification process, U q is the q-axis voltage, and Emod is the line-to-neutral EMF magnitude.

2. The method of claim 1, wherein, the q-axis given voltage is zero.

3. The method of claim 1, wherein, the coordinate conversion on the line electromotive force of the motor to obtain the d-axis voltage and the q-axis voltage comprises the following steps: performing Clark transformation on the line electromotive force of the motor to convert from abc coordinate system to αβ coordinate system; performing Park transformation on the voltage signal in the αβ coordinate system to obtain the d-axis voltage and the q-axis voltage in the dq coordinate system.

4. A frequency converter, characterized in that The motor flywheel starting program is stored in the memory and can be run on the processor, and when the processor executes the motor flywheel starting program, the motor flywheel starting method according to any one of claims 1-3 is realized.

5. A computer readable storage medium, characterized in that, The motor flywheel starting program is stored on the memory, and when the processor executes the motor flywheel starting program, the motor flywheel starting method according to any one of claims 1-3 is realized.

6. An electric machine flywheel starting apparatus characterized by, The method comprises the following steps: an acquisition module is configured to acquire three-phase back electromotive force of the motor; a signal processing module is configured to determine line electromotive force of the motor according to the three-phase back electromotive force to eliminate system noise signals; a coordinate transformation module is configured to perform coordinate conversion on the line electromotive force of the motor to obtain d-axis voltage and q-axis voltage; a modulus calculation module is configured to determine line back electromotive force modulus of the motor according to the d-axis voltage and the q-axis voltage; a phase-locked loop module is configured to perform phase-locked loop processing on the q-axis voltage to obtain operating frequency and line back electromotive force phase angle of the motor; a signal output module is configured to determine phase voltage modulus and phase voltage phase angle of the motor according to the line back electromotive force modulus and the line back electromotive force phase angle of the motor. A control module is configured to control the motor to perform flywheel starting according to an operating frequency of the motor, a phase voltage module value and a phase voltage phase angle; The signal output module determines the phase voltage module value and the phase voltage phase angle according to the following formula: θd = θ - 30° Wherein, Emodd is the phase voltage module value, Emod is the line back electromotive force module value, θd is the phase voltage phase angle, and θ is the line back electromotive force phase angle; An adaptive amplification module is configured to perform adaptive amplification processing on the q-axis voltage according to the line back electromotive force module value of the motor before phase-locked loop processing is performed on the q-axis voltage; The phase-locked loop module is configured to: determine a voltage difference between the q-axis voltage after adaptive amplification processing and a q-axis given voltage; perform PI regulation on the voltage difference to obtain an operating frequency of the motor; perform integral processing on the angular frequency after PI regulation to obtain the line back electromotive force phase angle; The adaptive amplification module determines the q-axis voltage after adaptive amplification processing according to the following formula: U qq = U q / Emod wherein U qq is the q-axis voltage after the adaptive amplification process, U q is the q-axis voltage, and Emod is the line-to-neutral EMF magnitude.

7. The apparatus of claim 6, wherein, The coordinate conversion module converts the line electromotive force of the motor to obtain a d-axis voltage and a q-axis voltage, including: performing Clark transformation on the line electromotive force of the motor to convert from an abc coordinate system to an αβ coordinate system; performing Park transformation on the voltage signal in the αβ coordinate system to obtain the d-axis voltage and the q-axis voltage in a dq coordinate system.

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