Motor flying start circuit and method, motor controller, and fusion terminal

Abstract

The invention discloses a motor flying start circuit and method, a motor controller, and a fusion terminal, wherein the motor flying start circuit includes a three-phase voltage sampling unit and a control unit with adjustable gain coefficients, the three-phase voltage sampling unit is used to obtain three-phase voltage sampling values, the control unit is used to determine the effective value of the motor back electromotive force according to the three-phase voltage sampling values, and obtain the quadrature axis component and the back electromotive force modulus value, and when the gain coefficient is determined to be adjusted according to the effective value of the motor back electromotive force, the gain parameter of the phase-locked loop is synchronously adjusted, and the quadrature axis component is phase-locked according to the phase-locked loop after the gain parameter is adjusted, and the back electromotive force frequency and back electromotive force phase are obtained, and the motor is controlled to start on the fly according to the back electromotive force modulus value, the back electromotive force frequency and the back electromotive force phase. The circuit adjusts the gain coefficient and the gain parameter so that the phase-locked loop can accurately lock the back electromotive force phase, frequency and amplitude, and realizes flying start without current impact.

Description

Technical Field

[0001] The present application relates to the field of motor control technology, and in particular to a motor flying start circuit and method, a motor controller, and a fusion terminal. Background Art

[0002] In the field of motor traction, the function of flying start is often needed. Flying start is a technology that uses the inverter to directly control the motor to run again when the motor is rotating, without waiting for the motor to stop. When the motor is flying started, if there is residual magnetism in the motor rotor and it rotates at high speed, the back electromotive force will be induced on the stator side of the motor. If the size and phase of the back electromotive force are not considered and the inverter is directly put into operation, a huge impact current may be generated, causing unnecessary property losses.

[0003] In related technologies, motor flying start usually uses software algorithms to lock the back EMF phase, frequency and amplitude, and put the inverter into operation at the appropriate time to reduce the impact current. However, in some scenarios, the back EMF induced by the motor is already very low, while the motor speed is still very high. Conventional phase-locked loops cannot guarantee accurate phase locking, which can easily generate impact current and cause damage to the motor and inverter. Summary of the invention

[0004] The present invention aims to solve one of the technical problems in the related art to at least a certain extent. To this end, the first purpose of the present invention is to propose a motor flying start circuit, which can ensure the sampling accuracy and signal-to-noise ratio of weak signals by automatically adjusting the gain coefficient of the sampling unit and the gain parameter of the phase-locked loop according to the effective value of the back-EMF, and achieve accurate locking of the motor back-EMF phase, frequency and amplitude in the full frequency band, and realize flying start without current impact; and by adjusting the gain parameter of the phase-locked loop, the convergence speed of the phase-locked loop can be accelerated, thereby locking the back-EMF frequency and back-EMF phase more quickly.

[0005] A second objective of the present invention is to provide a motor controller.

[0006] The third object of the present invention is to provide a method for flying start of a motor.

[0007] A fourth object of the present invention is to provide a computer-readable storage medium.

[0008] A fifth objective of the present invention is to provide a converged terminal.

[0009] To achieve the above-mentioned purpose, according to an embodiment of the first aspect of the present invention, a motor flying start circuit is proposed, comprising: a three-phase voltage sampling unit, the three-phase voltage sampling unit is provided with an adjustable gain coefficient, and the three-phase voltage sampling unit is used to sample the three-phase back electromotive force of the motor to obtain the three-phase voltage sampling value; a control unit, used to determine the effective value of the motor back electromotive force according to the three-phase voltage sampling value, and perform coordinate transformation on the three-phase voltage sampling value to obtain the quadrature component, and perform module value calculation on the three-phase voltage sampling value to obtain the back electromotive force module value; the control unit is also used to, when determining to adjust the gain coefficient according to the effective value of the motor back electromotive force, synchronously adjust the gain parameter of the phase-locked loop, and perform phase-locking processing on the quadrature axis component according to the phase-locked loop after the gain parameter is adjusted, to obtain the back electromotive force frequency and the back electromotive force phase, and control the motor to start on the fly according to the back electromotive force module value, the back electromotive force frequency and the back electromotive force phase.

[0010] According to the motor flying start circuit of the embodiment of the present invention, the three-phase back electromotive force of the motor is sampled by a three-phase voltage sampling unit to obtain a three-phase voltage sampling value, and the motor back electromotive force effective value is determined by a control unit according to the three-phase voltage sampling value, and the quadrature axis component and the back electromotive force modulus value are obtained, and when the gain coefficient of the three-phase voltage sampling unit is adjusted according to the motor back electromotive force effective value, the gain parameter of the phase-locked loop is synchronously adjusted, and the quadrature axis component is phase-locked according to the phase-locked loop after the gain parameter is adjusted, and the back electromotive force frequency and back electromotive force phase are obtained, and the motor is controlled to start on the fly according to the back electromotive force modulus value, back electromotive force frequency and back electromotive force phase. Thus, the gain coefficient of the sampling unit and the gain parameter of the phase-locked loop are automatically adjusted according to the back electromotive force effective value, which can ensure the sampling accuracy and signal-to-noise ratio of the weak signal, realize the accurate locking of the motor back electromotive force phase, frequency and amplitude of the full frequency band, and realize the flying start without current impact; and, adjusting the gain parameter of the phase-locked loop can speed up the convergence speed of the phase-locked loop, thereby locking the back electromotive force frequency and back electromotive force phase faster.

[0011] According to one embodiment of the present invention, each phase voltage sampling unit in the three-phase voltage sampling unit includes: a first resistor, one end of the first resistor is connected to a corresponding phase winding in the motor, and the other end of the first resistor is grounded; a second resistor, one end of the second resistor is connected to one end of the first resistor; a third resistor, one end of the third resistor is connected to the other end of the first resistor; a first capacitor, one end of the first capacitor is connected to the other end of the second resistor, and one end of the first capacitor has a first node, the other end of the first capacitor is connected to the other end of the third resistor, and the other end of the first capacitor has a second node; a fourth resistor, one end of the fourth resistor is connected to the first node; a first switch, one end of the first switch is connected to the other end of the fourth resistor, and the other end of the first switch is connected to the second node, and the first switch is configured to control the gain coefficient for adjustment; a first analog-to-digital converter, the first analog-to-digital converter is respectively connected to the first node and the second node, and is used to convert the voltage between the first node and the second node to obtain a phase voltage sampling value.

[0012] According to one embodiment of the present invention, the control unit is also used to, when the effective value of the motor back electromotive force is less than a first set value, adjust the gain coefficient to a first sampling gain by configuring the state of the first switch in each phase voltage sampling unit; when the effective value of the motor back electromotive force is greater than a second set value, adjust the gain coefficient to a second sampling gain by configuring the state of the first switch in each phase voltage sampling unit, wherein the second set value is greater than the first set value, and the second sampling gain is less than the first sampling gain.

[0013] According to an embodiment of the present invention, the adjustment ratio of the gain parameter is opposite to the adjustment ratio of the gain coefficient.

[0014] According to one embodiment of the present invention, the control unit is further configured to control the motor to start at zero frequency when the back electromotive force frequency is less than a preset minimum frequency.

[0015] According to one embodiment of the present invention, the control unit calculates the effective value of the motor back electromotive force according to the following formula: Among them, E rms is the effective value of the motor back EMF, m is the gain coefficient, E a 、E b 、E c is the three-phase voltage sampling value.

[0016] To achieve the above object, a motor controller is provided according to a second aspect of the present invention, comprising a motor flying starting circuit according to any of the above embodiments.

[0017] According to the motor controller of the embodiment of the present invention, by adopting the above-mentioned motor flying start circuit, the gain coefficient of the sampling unit and the gain parameter of the phase-locked loop are automatically adjusted according to the effective value of the back-EMF, so as to ensure the sampling accuracy and signal-to-noise ratio of weak signals, realize accurate locking of the motor back-EMF phase, frequency and amplitude in the full frequency band, and realize flying start without current impact; and, adjusting the gain parameter of the phase-locked loop can accelerate the convergence speed of the phase-locked loop, thereby locking the back-EMF frequency and back-EMF phase more quickly.

[0018] To achieve the above-mentioned purpose, a method for flying start of a motor is proposed according to an embodiment of the third aspect of the present invention, comprising: sampling the three-phase back EMF of the motor through a three-phase voltage sampling unit to obtain a three-phase voltage sampling value, wherein the three-phase voltage sampling unit is provided with an adjustable gain coefficient; determining the effective value of the motor back EMF according to the three-phase voltage sampling value, and performing coordinate transformation on the three-phase voltage sampling value to obtain a quadrature component, and performing module value calculation on the three-phase voltage sampling value to obtain a back EMF module value; when adjusting the gain coefficient according to the effective value of the motor back EMF, synchronously adjusting the gain parameter of the phase-locked loop, and performing phase-locking processing on the quadrature axis component according to the phase-locked loop after the gain parameter adjustment to obtain a back EMF frequency and a back EMF phase; and controlling the motor to fly start according to the back EMF module value, the back EMF frequency and the back EMF phase.

[0019] According to the motor flying start method of the embodiment of the present invention, firstly, the three-phase back electromotive force of the motor is sampled by a three-phase voltage sampling unit with adjustable gain coefficient to obtain a three-phase voltage sampling value, then the motor back electromotive force effective value is determined according to the three-phase voltage sampling value, and the quadrature axis component and the back electromotive force modulus are obtained, and then when the gain coefficient is adjusted according to the motor back electromotive force effective value, the gain parameter of the phase-locked loop is synchronously adjusted, and the quadrature axis component is phase-locked according to the phase-locked loop after the gain parameter is adjusted to obtain the back electromotive force frequency and the back electromotive force phase, and finally the motor is controlled to start on the fly according to the back electromotive force modulus, the back electromotive force frequency and the back electromotive force phase. Thus, the gain coefficient of the sampling unit and the gain parameter of the phase-locked loop are automatically adjusted according to the back electromotive force effective value, which can ensure the sampling accuracy and signal-to-noise ratio of the weak signal, realize the accurate locking of the motor back electromotive force phase, frequency and amplitude of the full frequency band, and realize the flying start without current impact; and, adjusting the gain parameter of the phase-locked loop can speed up the convergence speed of the phase-locked loop, thereby locking the back electromotive force frequency and the back electromotive force phase faster.

[0020] According to one embodiment of the present invention, the gain coefficient is adjusted according to the effective value of the motor back EMF, including: when the effective value of the motor back EMF is less than a first set value, the gain coefficient is adjusted to a first sampling gain by configuring the state of the first switch in each phase voltage sampling unit, wherein the first switch is used to control the gain coefficient for adjustment; when the effective value of the motor back EMF is greater than a second set value, the gain coefficient is adjusted to a second sampling gain by configuring the state of the first switch in each phase voltage sampling unit, wherein the second set value is greater than the first set value, and the second sampling gain is less than the first sampling gain.

[0021] According to an embodiment of the present invention, the adjustment ratio of the gain parameter is opposite to the adjustment ratio of the gain coefficient.

[0022] According to an embodiment of the present invention, when the back-EMF frequency is less than a preset minimum frequency, the method further comprises: controlling the motor to start at zero frequency.

[0023] According to one embodiment of the present invention, the effective value of the motor back electromotive force is calculated according to the following formula: Among them, E rms is the effective value of the motor back EMF, m is the gain coefficient, E a 、E b 、E c is the three-phase voltage sampling value.

[0024] To achieve the above-mentioned purpose, according to a fourth aspect of the present invention, a computer-readable storage medium is provided, on which a motor flying starting program is stored. When the motor flying starting program is executed by a processor, the motor flying starting method of any of the aforementioned embodiments is implemented.

[0025] According to the computer-readable storage medium of the embodiment of the present invention, by executing the above-mentioned computer program for motor flying start, the gain coefficient of the sampling unit and the gain parameter of the phase-locked loop are automatically adjusted according to the effective value of the back-EMF, so as to ensure the sampling accuracy and signal-to-noise ratio of weak signals, achieve precise locking of the motor back-EMF phase, frequency and amplitude in the full frequency band, and achieve flying start without current impact; and, adjusting the gain parameter of the phase-locked loop can speed up the convergence speed of the phase-locked loop, thereby locking the back-EMF frequency and back-EMF phase more quickly.

[0026] To achieve the above-mentioned purpose, according to an embodiment of the fifth aspect of the present invention, a fusion terminal is proposed, comprising a memory, a processor, and a motor flying start program stored in the memory and executable on the processor. When the processor executes the motor flying start program, the motor flying start method of any of the aforementioned embodiments is implemented.

[0027] In the fusion terminal according to the embodiment of the present invention, the processor executes the above-mentioned computer program for the motor flying start, and automatically adjusts the gain coefficient of the sampling unit and the gain parameter of the phase-locked loop according to the effective value of the back-EMF, thereby ensuring the sampling accuracy and signal-to-noise ratio of weak signals, and achieving precise locking of the motor back-EMF phase, frequency and amplitude in the full frequency band, and achieving flying start without current impact; and, adjusting the gain parameters of the phase-locked loop can speed up the convergence speed of the phase-locked loop, thereby locking the back-EMF frequency and back-EMF phase more quickly.

[0028] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a circuit diagram of a motor flying start circuit according to an embodiment of the present invention;

[0030] Figure 2 is a schematic diagram of the structure of a phase-locked loop according to an embodiment of the present invention;

[0031] Figure 3 is a schematic diagram of gain coefficient adjustment according to an embodiment of the present invention;

[0032] Figure 4 is a flow chart of a motor flying starting method according to an embodiment of the present invention;

[0033] Figure 5 is a flow chart of a motor flying starting method according to another embodiment of the present invention;

[0034] Figure 6 is a waveform diagram of motor output and given voltage and frequency according to one embodiment of the present invention;

[0035] Figure 7 is a schematic diagram of the structure of a converged terminal according to an embodiment of the present invention. DETAILED DESCRIPTION

[0036] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0037] The following describes a motor flying start circuit and method, a motor controller, a fusion terminal, and a storage medium according to an embodiment of the present invention with reference to the accompanying drawings.

[0038] Figure 1FIG. 1 is a circuit diagram of a motor flying start circuit according to an embodiment of the present invention. Figure 1 As shown, the motor flying start circuit includes: a three-phase voltage sampling unit 10 and a control unit 20.

[0039] The three-phase voltage sampling unit 10 is provided with an adjustable gain coefficient, and the three-phase voltage sampling unit 10 is used to sample the three-phase back electromotive force of the motor to obtain three-phase voltage sampling values, which are E a 、E b 、E c The control unit 20 is used to sample the three-phase voltage according to the value E a 、E b 、E c Determine the effective value of the motor back EMF E rms , and the three-phase voltage sampling value E a 、E b 、E c Perform coordinate transformation to obtain the quadrature axis component E q , and the three-phase voltage sampling value E a 、E b 、E c Perform module value calculation to obtain the back EMF module value E m The control unit 20 is also used to calculate the effective value of the motor back electromotive force E rms When it is determined that the gain coefficient is adjusted, the gain parameter of the phase-locked loop is adjusted synchronously, and the quadrature axis component E is adjusted according to the phase-locked loop after the gain parameter is adjusted. q Perform phase-locking processing to obtain the back EMF frequency E f and back EMF phase E θ , and according to the back EMF modulus E m , Back EMF frequency E f and back EMF phase E θ Control the motor to start on the fly.

[0040] Specifically, the three-phase voltage sampling unit 10 first obtains the three-phase voltage sampling value E a 、E b 、E c Then the control unit 20 calculates the three-phase voltage sampling value E a 、E b 、E c Determine the effective value of the motor back EMF E rms , and according to the effective value of the motor back EMF E rms Adjust the gain coefficient of the three-phase voltage sampling unit 10 so that the three-phase voltage sampling value E a 、E b 、E cCorresponding adjustments are made to improve the sampling accuracy and signal-to-noise ratio of the three-phase voltage sampling unit 10. Even if the motor back-EMF is very low, its sampling accuracy and signal-to-noise ratio can be guaranteed, so that the phase-locked loop can accurately lock the back-EMF frequency E f and back EMF phase E θ , thereby ensuring that the back-EMF amplitude, phase and frequency can be locked in the entire frequency band; at the same time, the control unit 20 also adjusts the gain parameters of the phase-locked loop to accelerate the convergence speed of the phase-locked loop and lock the back-EMF frequency E faster. f and back EMF phase E θ .

[0041] In an optional implementation, the control unit 20 includes an effective value calculation module 21, a module value calculation module 22, a phase-locked loop 23, and a flying start logic module 24. The effective value calculation module 21 is used to calculate the three-phase voltage sampling value E according to the three-phase voltage sampling value E. a 、E b 、E c Determine the effective value of the motor back EMF E rms Specifically, the effective value calculation module 21 can calculate the effective value E of the motor back electromotive force according to the following formula: rms :

[0042]

[0043] Among them, m is the gain coefficient, and m is set according to the actual operating conditions of the motor.

[0044] The effective value calculation module 21 can also calculate the three-phase voltage sampling value E according to the following formula: a 、E b 、E c Perform coordinate transformation to obtain the direct axis component E in the rotating coordinate system d and the quadrature axis component E q :

[0045]

[0046] Among them, θ is the motor rotor angle, which can be obtained by a rotor position sensor or a motor position observer.

[0047] The module value calculation module 22 calculates the three-phase voltage sampling value E according to the following formula: a 、E b 、E c Perform module value calculation to obtain the back EMF module value E m :

[0048]

[0049] like Figure 2 As shown, the phase-locked loop 23 is used to control the quadrature axis component Eq Perform phase-locking processing to obtain the back EMF frequency E f and back EMF phase E θ Specifically, the quadrature axis component E q The voltage difference between the voltage and 0 is input into the PI (Proportional Integral) regulator, and the back EMF frequency E is obtained through the PI regulator. f , and the back EMF frequency E f The input integration module calculates the back EMF phase E θ .

[0050] The flying start logic module 24 is used to start the motor according to the effective value of the motor back electromotive force E rms When the gain coefficient is determined to be adjusted, the gain parameter of the PI regulator is adjusted synchronously, thereby adjusting the gain parameter of the phase-locked loop, and according to the back-electromotive force modulus E m , Back EMF frequency E f and back EMF phase E θ Control the motor to start on the fly.

[0051] In the above embodiment, the gain coefficient of the sampling unit and the gain parameter of the phase-locked loop are automatically adjusted according to the effective value of the back-electromotive force, thereby improving the sampling accuracy and signal-to-noise ratio of the three-phase voltage sampling unit, so that the phase-locked loop can accurately lock the back-electromotive force phase, frequency and amplitude according to the quadrature-axis component of the effective value of the back-electromotive force, thereby realizing flying start without current impact; and, adjusting the gain parameter of the phase-locked loop can accelerate the convergence speed of the phase-locked loop, thereby locking the back-electromotive force frequency and back-electromotive force phase more quickly.

[0052] In some embodiments, Figure 1As shown, each phase voltage sampling unit 11 in the three-phase voltage sampling unit 10 includes: a first resistor R1 , a second resistor R2 , a third resistor R3 , a first capacitor C1 , a fourth resistor R4 , a first switch K1 and a first analog-to-digital converter 111 . Among them, one end of the first resistor R1 is connected to a corresponding phase winding in the motor, and the other end of the first resistor R1 is grounded; one end of the second resistor R2 is connected to one end of the first resistor R1; one end of the third resistor R3 is connected to the other end of the first resistor R1; one end of the first capacitor C1 is connected to the other end of the second resistor R2, and one end of the first capacitor C1 has a first node J1, the other end of the first capacitor C1 is connected to the other end of the third resistor R3, and the other end of the first capacitor C1 has a second node J2; one end of the fourth resistor R4 is connected to the first node J1; one end of the first switch K1 is connected to the other end of the fourth resistor R4, and the other end of the first switch K1 is connected to the second node J2, and the first switch K1 is configured to control the gain coefficient for adjustment; the first analog-to-digital converter 111 is respectively connected to the first node J1 and the second node J2, and is used to convert the voltage between the first node J1 and the second node J2 to obtain a phase voltage sampling value.

[0053] Specifically, the first resistor R1 is a voltage-dividing resistor. When the first switch K1 is disconnected, the fourth resistor R4 is not connected to the voltage sampling unit 11, and the voltage value collected by the first analog-to-digital converter 111 is the voltage value of each phase of the motor. When the first switch K1 is turned on, the fourth resistor R4 is connected to the voltage sampling unit 11, and the voltage value collected by the first analog-to-digital converter 111 is the voltage value at both ends of the fourth resistor R4, so that the three-phase voltage sampling value E a 、E b 、E c Reduce.

[0054] In the above embodiment, by controlling the on and off of the first switch, the gain coefficient of the three-phase voltage sampling unit can be adjusted so that the obtained three-phase voltage sampling value E a 、E b 、E c The size of changes, thereby improving the sampling accuracy and signal-to-noise ratio of the three-phase voltage sampling unit.

[0055] In some embodiments, Figure 3 As shown, the control unit 20 is also used to calculate the effective value of the motor back electromotive force E rms Less than the first set value E set1 When the gain coefficient is adjusted to the first sampling gain k, the state of the first switch K1 in each phase voltage sampling unit 11 is configured. max ; In the motor back EMF effective value E rms Greater than the second set value E set2When the gain coefficient is adjusted to the second sampling gain k by configuring the state of the first switch K1 in each phase voltage sampling unit 11 min , where the second set value E set2 Greater than the first set value E set1 , the second sampling gain k min Less than the first sampling gain k max .

[0056] That is to say, when the effective value of the motor back EMF is rms Less than the first set value E set1 When the three-phase voltage sampling value E a 、E b 、E c is relatively small, the state of the first switch K1 needs to be configured to be disconnected, the voltage across the first analog-to-digital converter 111 increases, and the gain coefficient at this time is the first sampling gain k max , so that the three-phase voltage sampling value E a 、E b 、E c When the effective value of the motor back electromotive force E rms Greater than the second set value E set2 When the three-phase voltage sampling value E a 、E b 、E c The first switch K1 needs to be configured to be in the on state, and the fourth resistor R4 is connected to each phase voltage sampling unit 11. The voltage across the first analog-to-digital converter 111 decreases, and the gain coefficient at this time is the second sampling gain k max , so that the three-phase voltage sampling value E a 、E b 、E c Reduce.

[0057] It should be noted that the first setting value E set1 and the second set value E set2 It is a fixed value, which is set according to the three-phase back EMF value actually generated by the motor in the working state.

[0058] In the above embodiment, whether to connect the fourth resistor to each phase voltage sampling unit is determined by controlling the state of the first switch, so that the voltage across the first analog-to-digital converter changes, thereby changing the three-phase voltage sampling value, thereby achieving the gain coefficient adjustment by configuring the state of the first switch.

[0059] In some embodiments, the adjustment ratio of the gain parameter is opposite to the adjustment ratio of the gain coefficient.

[0060] k max / k minThe value range is usually 5 to 20. At the same time, the gain coefficient of the PI regulator in the phase-locked loop changes k max / k min times.

[0061] Specifically, when the gain coefficient of the three-phase voltage sampling unit 10 is adjusted to N times of the original, the gain parameter of the phase-locked loop is adjusted to 1 / N of the original. For example, when the gain coefficient of the three-phase voltage sampling unit 10 is increased to 10 times of the original, the gain parameter of the phase-locked loop should be reduced to 1 / 10 of the original; when the gain coefficient of the three-phase voltage sampling unit 10 is reduced to 1 / 10 of the original, the gain parameter of the phase-locked loop should be increased to 10 times of the original, thereby accelerating the convergence speed of the PI regulator of the phase-locked loop, and then enabling the phase-locked loop to lock the phase and frequency of the back electromotive force more quickly. By synchronously adjusting the gain parameter and the gain coefficient, precise phase locking of the motor back electromotive force can be achieved.

[0062] In some embodiments, the control unit 20 is further configured to: f Less than the preset minimum frequency f min When the motor is controlled to start at zero frequency.

[0063] That is to say, when the back EMF frequency E f Less than the preset minimum frequency f min , indicating that the back EMF frequency E f Too low, no need to follow the back EMF frequency E f Control the motor to start, just start at zero frequency; when the back EMF frequency E f Greater than or equal to the preset minimum frequency f min , control the motor according to the back EMF frequency E f Starting, improving the efficiency of the motor flying start. That is, according to the back electromotive force frequency E f Determine whether to control the motor to start directly or to start on the fly.

[0064] In summary, according to the motor flying starting circuit of the embodiment of the present invention, the gain coefficient of the sampling unit and the gain parameter of the phase-locked loop are automatically adjusted according to the effective value of the back-EMF, and the sampling accuracy and signal-to-noise ratio of weak signals are guaranteed by combining soft and hard methods, so as to achieve accurate locking of the motor back-EMF phase, frequency and amplitude in the full frequency band, and realize flying starting without current impact; and, adjusting the gain parameter of the phase-locked loop can speed up the convergence speed of the phase-locked loop, thereby locking the back-EMF frequency and back-EMF phase more quickly.

[0065] Corresponding to the above embodiments, an embodiment of the present invention further proposes a motor controller, including the motor flying start circuit of any of the above embodiments.

[0066] According to the motor controller of the embodiment of the present invention, by adopting the above-mentioned motor flying start circuit, the gain coefficient of the sampling unit and the gain parameter of the phase-locked loop are automatically adjusted according to the effective value of the back-EMF, so as to ensure the sampling accuracy and signal-to-noise ratio of weak signals, realize accurate locking of the motor back-EMF phase, frequency and amplitude in the full frequency band, and realize flying start without current impact; and, adjusting the gain parameter of the phase-locked loop can accelerate the convergence speed of the phase-locked loop, thereby locking the back-EMF frequency and back-EMF phase more quickly.

[0067] Corresponding to the above embodiment, an embodiment of the present invention further proposes a motor flying starting method.

[0068] like Figure 4 As shown, the motor flying start method includes:

[0069] S101, sampling the three-phase back electromotive force of the motor through a three-phase voltage sampling unit to obtain a three-phase voltage sampling value E a 、E b 、E c , where the gain coefficient of the three-phase voltage sampling unit is adjustable.

[0070] S102, according to the three-phase voltage sampling value E a 、E b 、E c Determine the effective value of the motor back EMF E rms , and the three-phase voltage sampling value E a 、E b 、E c Perform coordinate transformation to obtain the quadrature axis component E q , and the three-phase voltage sampling value E a 、E b 、E c Perform module value calculation to obtain the back EMF module value E m .

[0071] In some embodiments, the effective value of the motor back EMF is calculated according to the following formula: rms :

[0072]

[0073] Among them, m is the gain coefficient, and m is set according to the actual operating conditions of the motor.

[0074] The three-phase voltage sampling value E is calculated according to the following formula a 、E b 、E c Perform coordinate transformation to obtain the direct axis component E in the rotating coordinate system d and the quadrature axis component E q :

[0075]

[0076] Among them, θ is the motor rotor angle, which can be obtained by a rotor position sensor or a motor position observer.

[0077] The three-phase voltage sampling value E is calculated according to the following formula a 、E b 、E c Perform module value calculation to obtain the back EMF module value E m :

[0078]

[0079] Among them, E m is the modulus of the back EMF.

[0080] Specifically, after obtaining the three-phase voltage sampling values, the motor back EMF effective value E is calculated using formula (1): rms , according to the effective value of the motor back electromotive force E rms After adjusting the gain coefficient, the three-phase voltage sampling value E after adjusting the gain coefficient is calculated using formula (2) and formula (3). a 、E b 、E c Perform coordinate transformation and modulus calculation to obtain the cross-axis component E q and the back EMF modulus E m . Due to the quadrature axis component E q It is the three-phase voltage sampling value E after adjusting the gain coefficient a 、E b 、E c So the quadrature axis component E q The accuracy and signal-to-noise ratio are relatively high, so the subsequent quadrature axis component E q When performing phase locking, the back EMF frequency E can be accurately locked f and back EMF phase E θ .

[0081] S103, according to the effective value of the motor back electromotive force E rms When it is determined that the gain coefficient is adjusted, the gain parameter of the phase-locked loop is adjusted synchronously, and the quadrature axis component E is adjusted according to the phase-locked loop after the gain parameter is adjusted. q Perform phase-locking processing to obtain the back EMF frequency E f and back EMF phase E θ .

[0082] In some embodiments, according to the effective value of the motor back EMF E rms Determine the gain factor to adjust, including: the effective value of the motor back EMF E rms Less than the first set value E set1When the gain coefficient is adjusted to the first sampling gain k, the state of the first switch K1 in each phase voltage sampling unit 11 is configured. max ; In the motor back EMF effective value E rms Greater than the second set value E set2 When the gain coefficient is adjusted to the second sampling gain k by configuring the state of the first switch K1 in each phase voltage sampling unit 11 min , where the second set value E set2 Greater than the first set value E set1 , the second sampling gain k min Less than the first sampling gain k max .

[0083] That is to say, when the effective value of the motor back EMF is rms Less than the first set value E set1 When the three-phase voltage sampling value E a 、E b 、E c is relatively small, the state of the first switch K1 needs to be configured to be disconnected, the voltage across the first analog-to-digital converter 111 increases, and the gain coefficient at this time is the first sampling gain k max , so that the three-phase voltage sampling value E a 、E b 、E c When the effective value of the motor back electromotive force E rms Greater than the second set value E set2 When the three-phase voltage sampling value E a 、E b 、E c The first switch K1 needs to be configured to be in the on state, and the fourth resistor R4 is connected to each phase voltage sampling unit 11. The voltage across the first analog-to-digital converter 111 decreases, and the gain coefficient at this time is the second sampling gain k max , so that the three-phase voltage sampling value E a 、E b 、E c Reduce.

[0084] It should be noted that the first setting value E set1 and the second set value E set2 It is a fixed value, which is set according to the three-phase back EMF value actually generated by the motor in the working state.

[0085] In the above embodiment, the fourth resistor is connected to each phase voltage sampling unit by controlling the state of the first switch, so that the voltage across the first analog-to-digital converter changes, thereby changing the three-phase voltage sampling value, and adjusting the gain coefficient by configuring the state of the first switch, thereby improving the sampling accuracy and signal-to-noise ratio of the three-phase voltage sampling unit.

[0086] In some embodiments, the adjustment ratio of the gain parameter is opposite to the adjustment ratio of the gain coefficient.

[0087] k max / k min The value range is usually 5 to 20. At the same time, the gain coefficient of the PI regulator in the phase-locked loop changes k max / k min times.

[0088] Specifically, when the gain coefficient of the three-phase voltage sampling unit is adjusted to N times of the original, the gain parameter of the phase-locked loop is adjusted to 1 / N of the original. For example, when the gain coefficient of the three-phase voltage sampling unit 10 is increased to 10 times of the original, the gain parameter of the phase-locked loop should be reduced to 1 / 10 of the original; when the gain coefficient of the three-phase voltage sampling unit 10 is reduced to 1 / 10 of the original, the gain parameter of the phase-locked loop should be increased to 10 times of the original, thereby accelerating the convergence speed of the PI regulator of the phase-locked loop, and then enabling the phase-locked loop to lock the phase and frequency of the back electromotive force more quickly. By synchronously adjusting the gain parameter and the gain coefficient, precise phase locking of the motor back electromotive force can be achieved.

[0089] S104, according to the back EMF modulus value E m , Back EMF frequency E f and back EMF phase E θ Control the motor to start on the fly.

[0090] In some embodiments, at the back EMF frequency E f Less than the preset minimum frequency f min The method further includes: controlling the motor to start at zero frequency.

[0091] That is to say, when the back EMF frequency E f Less than the preset minimum frequency f min , indicating that the back EMF frequency E f Too low, no need to follow the back EMF frequency E f Control the motor to start, just start at zero frequency; when the back EMF frequency E f Greater than or equal to the preset minimum frequency f min , control the motor according to the back EMF frequency E f Starting, improving the efficiency of the motor flying start. That is, according to the back electromotive force frequency E f Determine whether to control the motor to start directly or to start on the fly.

[0092] The technical solution of the present application is further described in detail below in conjunction with specific implementation methods:

[0093] like Figure 5 As shown, the motor flying start method includes:

[0094] S201, collecting the voltage value between the first node and the second node of each phase voltage sampling unit, and then performing analog-to-digital conversion on the voltage value between the first node and the second node through a first analog-to-digital converter to obtain a voltage sampling value for each phase, thereby obtaining a three-phase voltage sampling value.

[0095] S202, calculate the effective value of the motor back EMF according to the three-phase voltage sampling value, and configure the state of the first switch according to the effective value of the motor back EMF to adjust the gain coefficient, and synchronously adjust the gain parameter of the phase-locked loop; perform coordinate transformation on the three-phase voltage sampling value to obtain the quadrature-axis component.

[0096] S203, performing phase-locking processing on the quadrature-axis component by using the phase-locked loop after adjusting the gain parameter.

[0097] S204, obtaining the back-EMF frequency and the back-EMF phase.

[0098] S205, determining whether the back EMF frequency is less than a preset minimum frequency, if the back EMF frequency is greater than or equal to the preset minimum frequency, executing step S206, if the back EMF frequency is less than the preset minimum frequency, executing step S207.

[0099] S206, controlling the motor to start according to the back-EMF modulus, back-EMF frequency and back-EMF phase.

[0100] S207, controlling the motor to start at zero frequency (stationary).

[0101] In this embodiment, the first switch is controlled according to the effective value of the back-EMF to adjust the gain coefficient of the sampling unit, which can ensure the sampling accuracy and signal-to-noise ratio of weak signals, achieve precise locking of the motor back-EMF phase, frequency and amplitude in the full frequency band, and realize flying start without current shock; and, adjusting the gain parameters of the phase-locked loop can accelerate the convergence speed of the phase-locked loop, thereby locking the back-EMF frequency and back-EMF phase more quickly.

[0102] Furthermore, Figure 6 The waveform diagram of the voltage and frequency output by the motor using the starting method of the embodiment of the present invention is shown. The bus voltage of the motor is 1000V. The back EMF frequency is calculated to be 50Hz by the method of the embodiment of the present invention. The motor is controlled to start at a frequency of 50Hz. Figure 6 It can be seen that after 5s, the operating frequency of the motor suddenly increases from the initial frequency to close to 50Hz, and gradually approaches 50Hz, and finally reaches 50Hz.

[0103] In summary, according to the motor flying start method of the embodiment of the present invention, firstly, the three-phase back electromotive force of the motor is sampled by a three-phase voltage sampling unit with an adjustable gain coefficient to obtain a three-phase voltage sampling value, then the motor back electromotive force effective value is determined according to the three-phase voltage sampling value, and the quadrature axis component and the back electromotive force modulus are obtained, and then when the gain coefficient is determined to be adjusted according to the motor back electromotive force effective value, the gain parameter of the phase-locked loop is synchronously adjusted, and the quadrature axis component is phase-locked according to the phase-locked loop after the gain parameter is adjusted, and the back electromotive force frequency and the back electromotive force phase are obtained, and finally the motor is controlled to start on the fly according to the back electromotive force modulus, the back electromotive force frequency and the back electromotive force phase. Thus, the gain coefficient of the sampling unit and the gain parameter of the phase-locked loop are automatically adjusted according to the back electromotive force effective value, which can ensure the sampling accuracy and signal-to-noise ratio of the weak signal, realize the accurate locking of the motor back electromotive force phase, frequency and amplitude of the full frequency band, and realize the flying start without current impact; and, adjusting the gain parameter of the phase-locked loop can speed up the convergence speed of the phase-locked loop, thereby locking the back electromotive force frequency and the back electromotive force phase faster.

[0104] Corresponding to the above embodiments, an embodiment of the present invention further proposes a computer-readable storage medium on which a motor flying start program is stored. When the motor flying start program is executed by a processor, the motor flying start method of any of the above embodiments is implemented.

[0105] According to the computer-readable storage medium of the embodiment of the present invention, by executing the above-mentioned computer program for motor flying start, the gain coefficient of the sampling unit and the gain parameter of the phase-locked loop are automatically adjusted according to the effective value of the back-EMF, so as to ensure the sampling accuracy and signal-to-noise ratio of weak signals, achieve precise locking of the motor back-EMF phase, frequency and amplitude in the full frequency band, and achieve flying start without current impact; and, adjusting the gain parameter of the phase-locked loop can speed up the convergence speed of the phase-locked loop, thereby locking the back-EMF frequency and back-EMF phase more quickly.

[0106] Corresponding to the above embodiment, the embodiment of the present invention further proposes a fusion terminal, such as Figure 7 As shown, the fusion terminal 100 includes a memory 110, a processor 120, and a motor flying start program stored in the memory 110 and executable on the processor 120. When the processor 120 executes the motor flying start program, the motor flying start method of any of the aforementioned embodiments is implemented.

[0107] In the fusion terminal according to the embodiment of the present invention, the processor executes the above-mentioned computer program for the motor flying start, and automatically adjusts the gain coefficient of the sampling unit and the gain parameter of the phase-locked loop according to the effective value of the back-EMF, thereby ensuring the sampling accuracy and signal-to-noise ratio of weak signals, and achieving precise locking of the motor back-EMF phase, frequency and amplitude in the full frequency band, and achieving flying start without current impact; and, adjusting the gain parameters of the phase-locked loop can speed up the convergence speed of the phase-locked loop, thereby locking the back-EMF frequency and back-EMF phase more quickly.

[0108] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection portion with one or more wirings (electronic device), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.

[0109] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0110] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0111] In addition, the terms "first", "second", etc. used in the embodiments of the present invention are only used for descriptive purposes and should not be understood as indicating or implying relative importance, or implicitly indicating the number of technical features indicated in the present embodiment. Therefore, the features defined by the terms "first", "second", etc. in the embodiments of the present invention can explicitly or implicitly indicate that the embodiment includes at least one of the features. In the description of the present invention, the word "multiple" means at least two or two or more, such as two, three, four, etc., unless otherwise clearly and specifically defined in the embodiments.

[0112] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A motor flying start circuit, characterized in that: include: A three-phase voltage sampling unit, wherein the three-phase voltage sampling unit is provided with an adjustable gain coefficient and is used to sample the three-phase back electromotive force of the motor to obtain a three-phase voltage sampling value; A control unit, used to determine the effective value of the motor back electromotive force according to the three-phase voltage sampling values, perform coordinate transformation on the three-phase voltage sampling values ​​to obtain quadrature axis components, and perform module value calculation on the three-phase voltage sampling values ​​to obtain the back electromotive force module value; The control unit is also used to synchronously adjust the gain parameter of the phase-locked loop when determining to adjust the gain coefficient according to the effective value of the motor back-EMF, and perform phase-locking processing on the quadrature axis component according to the phase-locked loop after the gain parameter adjustment to obtain the back-EMF frequency and the back-EMF phase, and control the motor to start on the fly according to the back-EMF modulus, the back-EMF frequency and the back-EMF phase, wherein the adjustment ratio of the gain parameter is opposite to the adjustment ratio of the gain coefficient, the gain coefficient is the ratio of the effective value of the motor back-EMF to the back-EMF modulus, and the gain parameter is the parameter of the PI regulator of the phase-locked loop.

2. The motor flying starting circuit according to claim 1, characterized in that: Each phase voltage sampling unit in the three-phase voltage sampling unit comprises: A first resistor, one end of the first resistor is connected to a corresponding phase winding in the motor, and the other end of the first resistor is grounded; a second resistor, one end of the second resistor being connected to one end of the first resistor; a third resistor, one end of the third resistor being connected to the other end of the first resistor; a first capacitor, wherein one end of the first capacitor is connected to the other end of the second resistor, and one end of the first capacitor has a first node, and the other end of the first capacitor is connected to the other end of the third resistor, and the other end of the first capacitor has a second node; a fourth resistor, one end of which is connected to the first node; a first switch, wherein one end of the first switch is connected to the other end of the fourth resistor, the other end of the first switch is connected to the second node, and the first switch is configured to control the gain coefficient for adjustment; A first analog-to-digital converter is connected to the first node and the second node respectively, and is used to convert the voltage between the first node and the second node to obtain a phase voltage sampling value.

3. The motor flying start circuit according to claim 2, characterized in that: The control unit is also used for: When the effective value of the motor back electromotive force is less than the first set value, the gain coefficient is adjusted to the first sampling gain by configuring the state of the first switch in each phase voltage sampling unit; When the effective value of the motor back electromotive force is greater than a second set value, the gain coefficient is adjusted to a second sampling gain by configuring the state of the first switch in each phase voltage sampling unit, wherein the second set value is greater than the first set value, and the second sampling gain is less than the first sampling gain.

4. The motor flying start circuit according to any one of claims 1 to 3, characterized in that: The control unit is further configured to control the motor to start at zero frequency when the back-electromotive force frequency is less than a preset minimum frequency.

5. The motor flying start circuit according to any one of claims 1 to 3, characterized in that: The control unit calculates the effective value of the motor back electromotive force according to the following formula: Among them, E rms is the effective value of the motor back EMF, m is the gain coefficient, E a 、E b 、E c is the three-phase voltage sampling value.

6. A motor controller, characterized in that: The invention comprises a motor flying starting circuit according to any one of claims 1 to 5.

7. A method for starting a motor on the fly, characterized in that: include: The three-phase voltage sampling unit samples the three-phase back electromotive force of the motor to obtain a three-phase voltage sampling value, wherein the three-phase voltage sampling unit is provided with an adjustable gain coefficient; Determine the effective value of the motor back electromotive force according to the three-phase voltage sampling values, perform coordinate transformation on the three-phase voltage sampling values ​​to obtain quadrature axis components, and perform modulus calculation on the three-phase voltage sampling values ​​to obtain the back electromotive force modulus value; When the gain coefficient is adjusted according to the effective value of the motor back-electromotive force, the gain parameter of the phase-locked loop is adjusted synchronously, and the quadrature-axis component is phase-locked according to the phase-locked loop after the gain parameter is adjusted to obtain the back-electromotive force frequency and the back-electromotive force phase, wherein the adjustment ratio of the gain parameter is opposite to the adjustment ratio of the gain coefficient; The motor is controlled to perform flying start according to the back-EMF modulus, the back-EMF frequency and the back-EMF phase.

8. The method according to claim 7, characterized in that Determining to adjust the gain coefficient according to the effective value of the motor back electromotive force includes: When the effective value of the motor back electromotive force is less than a first set value, the gain coefficient is adjusted to a first sampling gain by configuring the state of a first switch in each phase voltage sampling unit, wherein the first switch is used to control the gain coefficient for adjustment; When the effective value of the motor back electromotive force is greater than a second set value, the gain coefficient is adjusted to a second sampling gain by configuring the state of the first switch in each phase voltage sampling unit, wherein the second set value is greater than the first set value, and the second sampling gain is less than the first sampling gain.

9. The method according to claim 7 or 8, characterized in that: When the back-EMF frequency is less than a preset minimum frequency, the method further includes: The motor is controlled to start at zero frequency.

10. The method according to claim 7 or 8, characterized in that: The effective value of the motor back EMF is calculated according to the following formula: Among them, E rms is the effective value of the motor back EMF, m is the gain coefficient, E a 、E b 、E c is the three-phase voltage sampling value.

11. A computer-readable storage medium, characterized in that: A motor flying start program is stored thereon, and when the motor flying start program is executed by the processor, the motor flying start method described in any one of claims 7-10 is implemented.

12. A fusion terminal, characterized in that: The invention comprises a memory, a processor and a motor flying start program stored in the memory and executable on the processor. When the processor executes the motor flying start program, the motor flying start method described in any one of claims 7 to 10 is implemented.

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