A method and device for reconstructing phase currents of a permanent magnet synchronous motor

Abstract

The application provides a phase current reconstruction method and device based on a permanent magnet synchronous motor, equipment and medium, comprising: obtaining the back electromotive force of the alpha axis according to the inductance and current of the d-axis and q-axis of the permanent magnet synchronous motor, the electrical angular velocity, the motor rotor flux, and the electrical angle of the motor rotor relative to the A-phase axis; obtaining the A-phase reconstructed current value at the current moment according to the back electromotive force of the alpha axis, the A-phase reconstructed current value at the last moment, the A-phase resistance and voltage, the electrical angular velocity, the inductance of the d-axis and q-axis, the current of the beta axis, and the PWM control period; synthesizing the space current i s The angle between the d-axis and the q-axis in the d-q axis coordinate system, the electrical angle of the rotor relative to the A-phase axis, and the synthesized space current i s The angle between the alpha axis and the beta axis in the alpha-beta axis coordinate system, and the feedback regulation control quantity obtained by combining the PI regulation mechanism. The problems of the prior art, such as the inability to reconstruct the A-phase current in all regions and the low reconstruction accuracy, are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to current reconstruction technology, and in particular to a phase current reconstruction method, device, equipment and medium based on a permanent magnet synchronous motor. BACKGROUND

[0002] The permanent magnet synchronous motor is widely used in new energy electric vehicles due to its low temperature rise, small size, light weight, small loss, long service life, high efficiency and obvious power saving effect. The vector control system of the permanent magnet synchronous motor powered by the three-phase voltage source inverter can indirectly detect the B-phase and C-phase alternating current values by modifying the inverter switching state during the effective vector action period, and calculate the A-phase current value according to the characteristics that the three-phase current sum is zero, to complete the A-phase current reconstruction. However, when the effective vector action time is too short or the modulation ratio is too low, and the reference voltage vector is close to one of the six effective vectors, the A-phase current cannot be reconstructed.

[0003] In the prior art, the pulse insertion method and the pulse phase shift method are used to prolong the action time of all effective vectors and shorten the action time of zero vectors, so as to reduce the non-reconstructable area of the phase current.

[0004] However, the prior art cannot complete the full-area reconstruction of the A-phase current, and the pulse insertion method and the pulse phase shift method result in the generation of asymmetric pulse width modulation waveforms, causing large distortion of the phase current and phase voltage, and causing motor torque fluctuation and electromagnetic noise. SUMMARY

[0005] The present application provides a phase current reconstruction method, device, equipment and medium based on a permanent magnet synchronous motor, to solve the problem of non-full-area reconstruction of the A-phase current.

[0006] In one aspect, the present application provides a phase current reconstruction method based on a permanent magnet synchronous motor, comprising:

[0007] According to the inductance and current of the d-axis and the q-axis of the permanent magnet synchronous motor, the electrical angular velocity of the permanent magnet synchronous motor, the motor rotor flux of the permanent magnet synchronous motor, and the electrical angle of the motor rotor relative to the A-phase axis, the counter electromotive force of the alpha-axis of the permanent magnet synchronous motor is obtained.

[0008] According to the counter electromotive force of the alpha-axis of the permanent magnet synchronous motor, the A-phase reconstruction current value at the last moment, the A-phase resistance and voltage of the permanent magnet synchronous motor, the electrical angular velocity of the permanent magnet synchronous motor, the inductance of the d-axis and the q-axis of the permanent magnet synchronous motor, the current of the beta-axis of the permanent magnet synchronous motor, and the pulse width modulation (PWM) control period, the A-phase reconstruction current value at the current moment of the permanent magnet synchronous motor is obtained.

[0009] In one specific embodiment, obtaining the back EMF of the permanent magnet synchronous motor along the α-axis based on the acquired inductance and current of the d-axis and q-axis, the electrical angular velocity of the permanent magnet synchronous motor, the rotor flux linkage of the permanent magnet synchronous motor, and the electrical angle of the rotor relative to the A-phase axis of the permanent magnet synchronous motor includes:

[0010] Based on the obtained inductance L of the d-axis and q-axis of the permanent magnet synchronous motor d L q and current i d i q The electric angular velocity ω of the permanent magnet synchronous motor e The rotor flux linkage of the permanent magnet synchronous motor and the electrical angle θ of the permanent magnet synchronous motor rotor relative to the A-phase axis. e The first formula is as follows:

[0011]

[0012] Obtain the back electromotive force E of the α-axis of the permanent magnet synchronous motor. α .

[0013] In one specific embodiment, obtaining the current A-phase reconstructed current value of the permanent magnet synchronous motor based on the back EMF of the α-axis of the permanent magnet synchronous motor, the A-phase reconstructed current value at the previous moment, the A-phase resistance and voltage of the permanent magnet synchronous motor, the electric angular velocity of the permanent magnet synchronous motor, the inductances of the d-axis and q-axis of the permanent magnet synchronous motor, the β-axis current of the permanent magnet synchronous motor, and the PWM control cycle includes:

[0014] According to the back electromotive force E of the α axis of the permanent magnet synchronous motor α The reconstructed current value of phase A at the previous moment, i a [n-1] The A-phase resistance R of the permanent magnet synchronous motor a and voltage U a The electric angular velocity ωe of the permanent magnet synchronous motor, and the inductance L of the permanent magnet synchronous motor along the d-axis and q-axis. d L q The current i of the β-axis of the permanent magnet synchronous motor β and the PWM control period T s The second formula is as follows: i a [n] = i a [n-1]+[U a -R a ×i a [n-1]+E α -ωe ×(L d -L q )×i β ]×T s / L d

[0015] Obtain the current value i of phase A reconfiguration of the permanent magnet synchronous motor at the current moment. a [n].

[0016] Where n represents time and is a positive integer.

[0017] In one specific implementation, it further includes:

[0018] According to the synthesized space current i s In the coordinate system formed by the d and q axes of the permanent magnet synchronous motor, the angle between the motor rotor and the d-axis is the electrical angle of the motor rotor relative to the A-phase axis, and the combined spatial current i is... s In the coordinate system formed by the α and β axes of the permanent magnet synchronous motor, the angle between the α axis and the β axis is used, and the feedback regulation control quantity is obtained by combining the PI regulation mechanism.

[0019] Based on the feedback adjustment control quantity, the A-phase reconfiguration current value of the permanent magnet synchronous motor at the current moment is adjusted to obtain the adjusted A-phase reconfiguration current value.

[0020] In one specific embodiment, the step of... based on the synthesized space current i s In the coordinate system formed by the d and q axes of the permanent magnet synchronous motor, the angle between the motor rotor and the d-axis is the electrical angle of the motor rotor relative to the A-phase axis, and the combined spatial current i is... s In the coordinate system formed by the α and β axes of the permanent magnet synchronous motor, the angle between the α axis and the β axis is used, and combined with the PI control mechanism, the feedback control quantity is obtained, including:

[0021] According to the synthesized space current i s In the coordinate system formed by the d and q axes of the permanent magnet synchronous motor, the angle θ with the d axis is... dq The electrical angle θ of the permanent magnet synchronous motor rotor relative to the A-phase axis e The synthesized space current i s In the coordinate system formed by the α and β axes of the permanent magnet synchronous motor, the angle θ with the α axis is... αβ The angle deviation formula is used:

[0022] θ err =θ dq +θ e -θ αβ

[0023] Obtaining an angle deviation θ err .

[0024] According to the angle deviation θ err , a PI regulation mechanism is adopted to obtain the feedback regulation control quantity.

[0025] In a specific embodiment, the adjustment processing of the A-phase reconstructed current value of the permanent magnet synchronous motor at the current time according to the feedback regulation control quantity includes:

[0026] According to the feedback regulation control quantity E a_flt , a phase current calculation feedback formula is adopted:

[0027]

[0028] Obtaining an adjusted A-phase current value i a [n] ′ .

[0029] In a second aspect, the application provides a phase current reconstruction device based on a permanent magnet synchronous motor, which includes:

[0030] An obtaining module is configured to obtain the inductance and current of the d-axis and q-axis of the permanent magnet synchronous motor, the electrical angular velocity of the permanent magnet synchronous motor, the motor rotor flux of the permanent magnet synchronous motor, and the electrical angle of the motor rotor relative to the A-phase axis of the permanent magnet synchronous motor.

[0031] A processing module is configured to obtain the counter electromotive force of the α-axis of the permanent magnet synchronous motor according to the inductance and current of the d-axis and q-axis of the permanent magnet synchronous motor, the electrical angular velocity of the permanent magnet synchronous motor, the motor rotor flux of the permanent magnet synchronous motor, and the electrical angle of the motor rotor relative to the A-phase axis of the permanent magnet synchronous motor.

[0032] The obtaining module is further configured to obtain the A-phase reconstructed current value at the previous time, the A-phase resistance and voltage of the permanent magnet synchronous motor, the current of the β-axis of the permanent magnet synchronous motor, and the pulse width modulation (PWM) control period.

[0033] The processing module is further configured to obtain the A-phase reconstructed current value of the permanent magnet synchronous motor at the current time according to the counter electromotive force of the α-axis of the permanent magnet synchronous motor, the A-phase reconstructed current value at the previous time, the A-phase resistance and voltage of the permanent magnet synchronous motor, the electrical angular velocity of the permanent magnet synchronous motor, the inductance of the d-axis and q-axis of the permanent magnet synchronous motor, the current of the β-axis of the permanent magnet synchronous motor, and the pulse width modulation (PWM) control period.

[0034] In one specific embodiment, the processing module is specifically configured to: based on the acquired inductance L of the d-axis and q-axis of the permanent magnet synchronous motor d L q and current i d i q The electric angular velocity ω of the permanent magnet synchronous motor e The rotor flux linkage of the permanent magnet synchronous motor and the electrical angle θ of the permanent magnet synchronous motor rotor relative to the A-phase axis. e The first formula is as follows:

[0035]

[0036] Obtain the back electromotive force E of the α-axis of the permanent magnet synchronous motor. α .

[0037] In one specific embodiment, the processing module is specifically used for:

[0038] According to the back electromotive force E of the α axis of the permanent magnet synchronous motor α The reconstructed current value of phase A at the previous moment, i a [n-1] The A-phase resistance R of the permanent magnet synchronous motor a and voltage U a The electric angular velocity ω of the permanent magnet synchronous motor e The inductance L of the d-axis and q-axis of the permanent magnet synchronous motor d L q The current i of the β-axis of the permanent magnet synchronous motor β and PWM control period T s The second formula is adopted as follows:

[0039] i a [n] = i a [n-1]+[U a -R a ×i a [n-1]+E α -ω e ×(L d -L q )×i β ]×T s / L d

[0040] Obtain the current value i of phase A reconfiguration of the permanent magnet synchronous motor at the current moment. a [n].

[0041] Where n represents time and is a positive integer.

[0042] In a specific implementation, further comprising:

[0043] a feedback module configured to obtain a feedback adjustment control value according to the synthesized space current i s an angle between the d-axis and the A-phase axis in a coordinate system formed by the d-axis and the q-axis of the permanent magnet synchronous motor s an angle between the α-axis and the A-phase axis in a coordinate system formed by the α-axis and the β-axis of the permanent magnet synchronous motor

[0044] The processing module is further configured to adjust the A-phase reconstructed current value of the permanent magnet synchronous motor at the current time according to the feedback adjustment control value, to obtain an adjusted A-phase reconstructed current value.

[0045] In a specific implementation, the feedback module is specifically configured to:

[0046] obtain a feedback adjustment control value according to the synthesized space current i s an angle between the d-axis and the A-phase axis in a coordinate system formed by the d-axis and the q-axis of the permanent magnet synchronous motor dq an angle between the α-axis and the A-phase axis in a coordinate system formed by the α-axis and the β-axis of the permanent magnet synchronous motor s an angle between the d-axis and the A-phase axis in a coordinate system formed by the d-axis and the q-axis of the permanent magnet synchronous motor αβ adopt an angle deviation formula:

[0047] θ err = θ dq + θ e - θ αβ

[0048] obtain an angle deviation θ err .

[0049] obtain a feedback adjustment control value according to the angle deviation θ err , and adopt a PI adjustment mechanism.

[0050] In a specific implementation, the processing module is specifically further configured to:

[0051] obtain an adjusted A-phase current value i a_flt according to the feedback adjustment control value E

[0052]

[0053] obtain an adjusted A-phase current value i a [n] ′ .

[0054] In a third aspect, the application provides an automobile, comprising: a permanent magnet synchronous motor and a motor controller.

[0055] The motor controller is configured to perform the method for reconstructing phase current of a permanent magnet synchronous motor according to the first aspect.

[0056] In a fourth aspect, the application provides a readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the method for reconstructing phase current of a permanent magnet synchronous motor according to the first aspect.

[0057] The application provides a method, device, equipment and medium for reconstructing phase current of a permanent magnet synchronous motor. The back EMF of the α-axis of the permanent magnet synchronous motor is obtained according to the inductance and current of the d-axis and q-axis of the permanent magnet synchronous motor, the electrical angular velocity of the permanent magnet synchronous motor, the motor rotor flux of the permanent magnet synchronous motor, and the electrical angle of the motor rotor relative to the A-axis. The A-phase reconstructed current value at the current time of the permanent magnet synchronous motor is obtained according to the back EMF of the α-axis of the permanent magnet synchronous motor, the A-phase reconstructed current value at the previous time, the A-phase resistance and voltage of the permanent magnet synchronous motor, the electrical angular velocity of the permanent magnet synchronous motor, the inductance of the d-axis and q-axis of the permanent magnet synchronous motor, the current of the β-axis of the permanent magnet synchronous motor, and the pulse width modulation (PWM) control period. The synthesized space current i s The angle between the d-axis and the A-axis in the coordinate system formed by the d-axis and q-axis of the permanent magnet synchronous motor, the electrical angle of the motor rotor relative to the A-axis, and the synthesized space current i s The angle between the α-axis and the A-axis in the coordinate system formed by the α-axis and β-axis of the permanent magnet synchronous motor, and the feedback adjustment control quantity obtained by combining the PI adjustment mechanism. The A-phase reconstructed current value at the current time of the permanent magnet synchronous motor is adjusted according to the feedback adjustment control quantity to obtain the adjusted A-phase reconstructed current value. Compared with the pulse insertion method and the pulse phase shift method in the prior art, the application prolongs the action time of all effective vectors and shortens the action time of zero vectors to reduce the non-reconstructable region of the A-phase current. According to the vector relationship between the A-phase current voltage and the current voltage of the d-axis, q-axis, α-axis and β-axis, the application constructs the A-phase current formula to realize the reconstruction of the A-phase current in all regions and all working conditions. According to the angle relationship, the feedback adjustment mechanism is constructed to reduce the A-phase current reconstruction error and improve the accuracy. BRIEF DESCRIPTION OF DRAWINGS

[0058] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0059] Figure 1 A flowchart of an embodiment of a phase current reconstruction method based on a permanent magnet synchronous motor provided by the present application is shown in the figure.

[0060] Figure 2 A flowchart of an embodiment of a phase current reconstruction method based on a permanent magnet synchronous motor provided by the present application is shown in the figure.

[0061] Figure 3 An angle relationship diagram of the phase current in the coordinate system composed of d and q axes and the coordinate system composed of α and β axes is shown in the figure.

[0062] Figure 4 A structural diagram of an embodiment of a phase current reconstruction device based on a permanent magnet synchronous motor provided by the present application is shown in the figure. DETAILED DESCRIPTION

[0063] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the following will combine the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments made by those skilled in the art according to the inspiration of the present embodiments are within the scope of protection of the present application.

[0064] The terms "first", "second", "third", "fourth" and the like (if any) in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not necessarily limit to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0065] In the prior art, the pulse insertion method and the pulse phase-shifting method are used to prolong the action time of all effective vectors and shorten the action time of zero vectors, so as to reduce the non-reconstructable region of the A-phase current, but the A-phase current is still not globally reconstructable, and the pulse insertion method and the pulse phase-shifting method result in the generation of asymmetric pulse width modulation waveforms, which causes large distortion of phase current and phase voltage, and causes motor torque fluctuation and electromagnetic noise. To solve the above problems, the technical concept of the present application is how to achieve global reconstruction of the A-phase current and increase the current reconstruction accuracy.

[0066] In the following, the technical solutions of the present application will be described in detail through specific embodiments. It should be noted that the following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0067] Figure 1 A flowchart of a first embodiment of a phase current reconstruction method based on a permanent magnet synchronous motor according to the present application is shown in FIG. 1. Figure 1 The phase current reconstruction method based on the permanent magnet synchronous motor specifically includes the following steps:

[0068] Step S101: Obtain the back electromotive force of the α-axis of the permanent magnet synchronous motor according to the inductance and current of the d-axis and the q-axis of the permanent magnet synchronous motor, the electrical angular velocity of the permanent magnet synchronous motor, the motor rotor flux of the permanent magnet synchronous motor, and the electrical angle of the motor rotor relative to the A-phase axis.

[0069] Step S102: Obtain the A-phase reconstruction current value at the current time of the permanent magnet synchronous motor according to the back electromotive force of the α-axis of the permanent magnet synchronous motor, the A-phase reconstruction current value at the previous time, the A-phase resistance and voltage of the permanent magnet synchronous motor, the electrical angular velocity of the permanent magnet synchronous motor, the inductance of the d-axis and the q-axis of the permanent magnet synchronous motor, the current of the β-axis of the permanent magnet synchronous motor, and the pulse width modulation (PWM) control period.

[0070] In this embodiment, the expression for phase A current is obtained based on the relationship between the ABC phase coordinate system, the α-axis and β-axis coordinate systems, and the d-axis and q-axis coordinate systems. This allows phase A current reconstruction to be independent of switch states and the DC-side current sensor of the controller. Compared to existing pulse insertion and pulse phase shift methods, which only reduce the non-reconfigurable area of ​​phase current and have stringent application conditions, the phase A current reconstruction method provided in this application has wide applications and can achieve full-range reconstruction of phase A under all operating conditions. On the other hand, compared to existing technologies, this application does not require adjustment of the waveform generated by SVPWM, thereby avoiding large distortions in phase current and phase voltage, and thus avoiding torque fluctuations and electromagnetic noise. In addition, this application does not rely on sampling of the bus current to indirectly obtain the phase current, thus effectively avoiding the generation of errors such as DC current oscillation error, DC current distortion error, DC current bias error, DC current amplitude error, sampling phase error, and sampling delay error.

[0071] Figure 2 A flowchart illustrating a second embodiment of a phase current reconstruction method based on a permanent magnet synchronous motor provided in this application; see also Figure 2 The phase current reconstruction method based on a permanent magnet synchronous motor includes the following steps:

[0072] Step S201: Based on the obtained inductance L of the permanent magnet synchronous motor along the d-axis and q-axis... d L q and current i d i q The electric angular velocity ω of a permanent magnet synchronous motor e Rotor flux linkage of permanent magnet synchronous motor And the electrical angle θ of the permanent magnet synchronous motor rotor relative to the A-phase axis. e The first formula is as follows:

[0073]

[0074] Obtain the back electromotive force E of the α-axis of the permanent magnet synchronous motor. α .

[0075] Step S202: Based on the back electromotive force E of the α-axis of the permanent magnet synchronous motor α The reconstructed current value of phase A at the previous moment, i a [n-1] The resistance R of phase A of the permanent magnet synchronous motor a and voltage U a The electric angular velocity ω of a permanent magnet synchronous motor e The inductance L of the d-axis and q-axis of a permanent magnet synchronous motor d L q The current i on the β axis of a permanent magnet synchronous motor β and the pulse width modulation (PWM) control period Ts The second formula is adopted as follows:

[0076] i a [n] = i a [n-1]+[U a -R a ×i a [n-1]+E α -ω e ×(L d -L q )×i β ]×T s / L d

[0077] Obtain the current value i of phase A reconfiguration current of the permanent magnet synchronous motor at the current moment. a [n].

[0078] Where n represents time and is a positive integer.

[0079] In this embodiment, U a The voltage of phase A can be obtained by sampling and conversion using hardware circuitry; R a The resistance of phase A is obtained through actual measurement or estimation; L d L q The inductances of the motor along the d-axis and q-axis are obtained through actual measurement or estimation; ω e The electric angular velocity of the electric motor is obtained through actual measurement using a sensor or rotary transformer; i β E represents the current along the β-axis of the motor, obtained by measuring the B-phase and C-phase currents using a current sensor and applying the Clarke transform formula. α Let i be the back electromotive force along the α-axis of the motor, an intermediate product in the derivation, and its specific value need not be determined; d i q The currents of the motor along the d-axis and q-axis are measured using current sensors for phase B and phase C, and the current i is obtained using the Clarke transform formula. α and i β Then, it can be obtained using the Park formula; The rotor flux linkage of the electric motor is obtained through actual measurement or estimation; θ e The electrical angle of the motor rotor relative to the A-phase axis is obtained through an angle sensor or estimation; T s This is the pulse width modulation (PWM) control cycle.

[0080] In this embodiment, the specific method for obtaining the first formula and the second formula is as follows:

[0081] Based on the stator voltage equations of the rotating coordinate system with d-axis and q-axis:

[0082]

[0083] wherein U d , U q are the d-axis and q-axis voltages, R is any phase resistance, which is obtained by measurement or estimation.

[0084] and the extended back EMF:

[0085]

[0086] The relationship formula of the d-axis and q-axis voltages and the back EMF can be obtained as follows:

[0087]

[0088] According to the inverse Park formula:

[0089]

[0090]

[0091] wherein U α , U β are the α-axis and β-axis voltages of the motor.

[0092] and the relationship formula of the d-axis and q-axis voltages and the back EMF can be obtained as follows:

[0093] Specifically,

[0094]

[0095] Thus, the stator voltage equation and the back EMF equation of the α, β-axis stationary coordinate system can be derived as follows:

[0096]

[0097] wherein E β is the back EMF of the β-axis of the motor, which is an intermediate product in the derivation and can not be obtained specifically. After arrangement, the following can be obtained:

[0098]

[0099] According to the Clarke transformation formula:

[0100]

[0101] wherein i a , i b , i c are the A, B, C phase currents, i b , i c are measured by the current sensor, and i a is obtained in the present application.

[0102]

[0103] wherein, U a , U b , U c are A, B, C phase voltages, which can be obtained by sampling conversion of hardware circuit.

[0104] And the sum of three-phase voltages is equal to 0 and the sum of three-phase currents is equal to 0, it can be known that:

[0105] U α = U a

[0106] i α = i a

[0107] i α is the current of the α axis of the motor.

[0108] Therefore, it can be obtained that:

[0109]

[0110] R is a phase resistance, and A phase is studied in the application, so R is replaced by R a , that is:

[0111]

[0112] E α is substituted into the formula of U a , and difference calculation is performed, so it can be obtained that:

[0113] i a [n] = i a [n-1] + [U a -R a × i a [n-1] + E α - ω e × (L d -L q ) × i β ] × T s / L d

[0114] Step S203: obtaining the feedback regulation control quantity according to the synthesized space current i s The angle between the d, q axis of the permanent magnet synchronous motor and the d axis, the electrical angle of the motor rotor of the permanent magnet synchronous motor relative to the A phase axis, the synthesized space current i s The angle between the α, β axis of the permanent magnet synchronous motor and the α axis, and combining the PI regulation mechanism, the feedback regulation control quantity is obtained.

[0115] In the embodiment, optionally, a specific implementation of the step S203 is as follows:

[0116] According to the synthesized space current i s In the coordinate system formed by the d, q axes of the permanent magnet synchronous motor, the angle θ dq between the d axis and the A-phase axis of the motor rotor of the permanent magnet synchronous motor e The synthesized space current i s In the coordinate system formed by the α, β axes of the permanent magnet synchronous motor, the angle θ αβ between the α axis and the A-phase axis of the motor rotor of the permanent magnet synchronous motor

[0117] θ err = θ dq + θ e - θ αβ

[0118] Obtain the angle deviation θ err .

[0119] According to the angle deviation θ err , a PI regulation mechanism is adopted to obtain a feedback regulation control quantity.

[0120] Step S204: According to the feedback regulation control quantity, the A-phase reconstructed current value of the current moment of the permanent magnet synchronous motor is adjusted and processed to obtain an adjusted A-phase reconstructed current value.

[0121] In the embodiment, optionally, a specific implementation of the step S204 is as follows:

[0122] According to the feedback regulation control quantity E a_flt , a phase current calculation feedback formula is adopted:

[0123]

[0124] Obtain the adjusted A-phase current value i a [n] ′ .

[0125] In the embodiment, U a is the A-phase voltage, which can be obtained by hardware circuit sampling conversion; R a is the A-phase resistance, which is obtained by actual measurement or estimation; L d , L q are the inductances of the d and q axes of the motor, which are obtained by actual measurement or estimation; ω e is the electrical angular velocity of the motor, which is obtained by actual measurement through a sensor or a resolver; i β is the current of the β axis of the motor, which is obtained according to the Clarke transformation formula through actual measurement of the B-phase and C-phase currents by a current sensor; E αis the back EMF of the α axis of the motor, and is not required to be a specific value for deriving the intermediate product; i d 、i q is the current of the d axis and q axis of the motor, the B phase and C phase currents are measured by a current sensor, and i α and i β are obtained according to the Clarke transformation formula; and is the motor rotor flux of the motor, which is obtained by measurement or estimation; θ e is the electrical angle of the motor rotor relative to the A phase axis, which is obtained by an angle sensor or estimation; T s is the pulse width modulation (PWM) control period; i a [n-1] is the A phase reconstructed current value after adjustment at the last time.

[0126] In the embodiment, according to the relationship among the ABC phase coordinate system, the α axis and β axis coordinate system, and the d axis and q axis coordinate system, the A phase current expression is obtained, and the feedback adjustment control quantity is obtained by combining the PI adjustment mechanism. The A phase reconstructed current value at the current time is adjusted according to the feedback adjustment control quantity, so as to obtain the A phase reconstructed current value after adjustment. Compared with the pulse insertion method and the pulse phase shifting method in the prior art, the first application does not need to adjust the waveform generated by the SVPWM, so as to avoid causing large distortion of the phase current and the phase voltage, and further avoid causing torque fluctuation and electromagnetic noise. The second application does not depend on the sampling of the bus current to indirectly obtain the phase current, so as to effectively avoid the generation of errors such as direct current oscillation error, direct current distortion error, direct current bias error, direct current amplitude error, sampling phase error, and sampling delay error. The third application does not depend on the bus current, the switching state, and the effective vector action time, and can realize the reconstruction of the A phase current in all working conditions and all regions. In addition, the application increases the feedback adjustment mechanism, reduces the error of calculating the phase current only by using the hybrid phase voltage equation, and effectively improves the reconstruction accuracy of the phase current.

[0127] On the basis of the above embodiment, the angle deviation formula is:

[0128] θ err = θ dq + θ e - θ αβ

[0129] is obtained in the following manner:

[0130] As Figure 3 shown in the angle relationship diagram of the phase current in the coordinate system composed of the d axis and the q axis and the coordinate system composed of the α axis and the β axis, the synthesized space current i s forms an angle θ dq, the electrical angle of the motor rotor of the permanent magnet synchronous motor relative to the A-phase axis e , the synthesized space current i s In the coordinate system formed by the α, β axes of the permanent magnet synchronous motor, the angle θ αβ has the following relationship:

[0131] θ αβ = θ dq + θ e

[0132] When the calculated i α [n] is not equal to the actually measured i α , there is an angle deviation formula:

[0133] θ err = θ dq + θ e - θ αβ

[0134] Specifically, the synthesized space current i s In the coordinate system formed by the α, β axes of the permanent magnet synchronous motor, the angle θ αβ and the angle θ dq In the coordinate system formed by the d, q axes of the permanent magnet synchronous motor, the angle θ s is expressed as follows:

[0135]

[0136] Where i s represents the synthesized space current, F d represents the motor stator magnetic motive force, and ω1 represents the current motor electrical angular velocity.

[0137] Figure 4 A structure schematic diagram of an embodiment of a phase current reconstruction device based on a permanent magnet synchronous motor provided by the present application is shown in FIG. 1. As shown in FIG. 1, the phase current reconstruction device 30 based on the permanent magnet synchronous motor includes an acquisition module 31 and a processing module 32.

[0138] Specifically, the acquisition module 31 is used to acquire the inductance and current of the d-axis and q-axis of the permanent magnet synchronous motor (PMSM), the electrical angular velocity of the PMSM, the rotor flux linkage of the PMSM, and the electrical angle of the PMSM rotor relative to the A-phase axis. The processing module 32 is used to acquire the back EMF of the α-axis of the PMSM based on the acquired inductance and current of the d-axis and q-axis of the PMSM, the electrical angular velocity of the PMSM, the rotor flux linkage of the PMSM, and the electrical angle of the PMSM rotor relative to the A-phase axis. The acquisition module 31 is also used to acquire the A-phase reconstructed current value, the A-phase resistance and voltage of the PMSM, the β-axis current of the PMSM, and the pulse width modulation (PWM) control cycle at the previous moment. The processing module 32 is also used to obtain the current A-phase reconstructed current value of the permanent magnet synchronous motor based on the back EMF of the α-axis of the permanent magnet synchronous motor, the A-phase reconstructed current value of the previous moment, the A-phase resistance and voltage of the permanent magnet synchronous motor, the electric angular velocity of the permanent magnet synchronous motor, the inductance of the d-axis and q-axis of the permanent magnet synchronous motor, the β-axis current of the permanent magnet synchronous motor, and the pulse width modulation (PWM) control cycle.

[0139] In this embodiment, the device can perform the above-described... Figure 1 The method embodiments shown are similar in principle and technical effect, and will not be described again here.

[0140] Based on the above embodiments, the processing module 32 can be specifically used for:

[0141] Based on the obtained inductance L of the permanent magnet synchronous motor along the d-axis and q-axis d L q and current i d i q The electric angular velocity ω of a permanent magnet synchronous motor e Rotor flux linkage of permanent magnet synchronous motor And the electrical angle θ of the permanent magnet synchronous motor rotor relative to the A-phase axis. e The first formula is as follows:

[0142]

[0143] Obtain the back electromotive force E of the α-axis of the permanent magnet synchronous motor. α .

[0144] In addition, the processing module 32 can also be specifically used for:

[0145] Based on the back electromotive force E of the α axis of the permanent magnet synchronous motor α The reconstructed current value of phase A at the previous moment, i a [n-1] The resistance R of phase A of the permanent magnet synchronous motor a and voltage Ua The electric angular velocity ω of a permanent magnet synchronous motor e The inductance L of the d-axis and q-axis of a permanent magnet synchronous motor d L q The current i on the β axis of a permanent magnet synchronous motor β and the pulse width modulation (PWM) control period T s The second formula is adopted as follows:

[0146] i a [n] = i a [n-1]+[U a -R a ×i a [n-1]+E α -ω e ×(L d -L q )×i β ]×T s / L d

[0147] Obtain the current value i of phase A reconfiguration current of the permanent magnet synchronous motor at the current moment. a [n].

[0148] Where n represents time and is a positive integer.

[0149] Based on the above embodiments, the phase current reconstruction device 30 based on a permanent magnet synchronous motor further includes a feedback module 33. This feedback module 33 is used to reconstruct the phase current based on the synthesized space current i. s In the coordinate system formed by the d and q axes of the permanent magnet synchronous motor, the angle between the rotor and the d-axis represents the electrical angle of the motor rotor relative to the A-phase axis, and the resultant spatial current i s In the coordinate system formed by the α and β axes of the permanent magnet synchronous motor, the angle between the α axis and the β axis is used, and combined with the PI control mechanism, to obtain the feedback regulation control quantity. Then, the processing module 32 is also used to adjust the A-phase reconstructed current value of the permanent magnet synchronous motor at the current moment according to the feedback regulation control quantity, so as to obtain the adjusted A-phase reconstructed current value.

[0150] Alternatively, the feedback module 33 is specifically used for:

[0151] According to the synthesized space current i s In the coordinate system formed by the d and q axes of the permanent magnet synchronous motor, the angle θ with the d axis is... dq The electrical angle θ of the rotor of a permanent magnet synchronous motor relative to the axis of phase A. e Synthetic space current i s In the coordinate system formed by the α and β axes of the permanent magnet synchronous motor, the angle θ with the α axis is... αβ The angle deviation formula is used:

[0152] θ err = θ dq + θ e - θ αβ

[0153] obtaining the angle deviation θ err .

[0154] According to the angle deviation θ err , a PI regulation mechanism is adopted to obtain a feedback regulation control quantity.

[0155] The processing module 32 is specifically further configured to:

[0156] According to the feedback regulation control quantity E a_flt , a phase current calculation feedback formula is adopted:

[0157]

[0158] obtaining the regulated A-phase current value i a [n]'.

[0159] The application provides an automobile, comprising: a permanent magnet synchronous motor and a motor controller.

[0160] The motor controller is configured to implement the technical solutions provided in any of the preceding embodiments.

[0161] The application further provides a readable storage medium having a computer program stored thereon, and the computer program is executed by a processor to implement the technical solutions provided in any of the preceding embodiments.

[0162] Those skilled in the art can understand that all or part of the steps of the above-mentioned method embodiments can be completed by program instruction-related hardware. The foregoing program can be stored in a computer-readable storage medium. When the program is executed, the steps of the above-mentioned method embodiments are executed; and the foregoing storage medium includes: ROM, RAM, magnetic disc or optical disc and various program code storage media.

[0163] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the application, and not to limit them; although the application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the application.

Claims

1. A phase current reconstruction method based on a permanent magnet synchronous motor, characterized in that, include: Based on the obtained inductance and current of the d-axis and q-axis of the permanent magnet synchronous motor, the electric angular velocity of the permanent magnet synchronous motor, the rotor flux linkage of the permanent magnet synchronous motor, and the electric angle of the rotor of the permanent magnet synchronous motor relative to the A-phase axis, the back electromotive force of the α-axis of the permanent magnet synchronous motor is obtained. The current A-phase reconstructed current value of the permanent magnet synchronous motor is obtained based on the back EMF of the α-axis of the permanent magnet synchronous motor, the A-phase reconstructed current value of the previous moment, the A-phase resistance and voltage of the permanent magnet synchronous motor, the electric angular velocity of the permanent magnet synchronous motor, the inductance of the d-axis and q-axis of the permanent magnet synchronous motor, the β-axis current of the permanent magnet synchronous motor, and the pulse width modulation (PWM) control cycle. According to the synthesized space current i s In the coordinate system formed by the d and q axes of the permanent magnet synchronous motor, the angle between the motor rotor and the d-axis is the electrical angle of the motor rotor relative to the A-phase axis, and the combined spatial current i is... s In the coordinate system formed by the α and β axes of the permanent magnet synchronous motor, the angle between the α axis and the β axis is obtained, and the feedback regulation control quantity is obtained in combination with the PI regulation mechanism. Based on the feedback adjustment control quantity, the A-phase reconfiguration current value of the permanent magnet synchronous motor at the current moment is adjusted to obtain the adjusted A-phase reconfiguration current value.

2. The phase current reconstruction method based on a permanent magnet synchronous motor according to claim 1, characterized in that, The step of obtaining the back EMF of the permanent magnet synchronous motor along the α-axis based on the obtained inductance and current of the d-axis and q-axis, the electrical angular velocity of the permanent magnet synchronous motor, the rotor flux linkage of the permanent magnet synchronous motor, and the electrical angle of the rotor relative to the A-phase axis, includes: Based on the obtained inductance L of the d-axis and q-axis of the permanent magnet synchronous motor d L q and current i d i q The electric angular velocity ω of the permanent magnet synchronous motor e The rotor flux linkage of the permanent magnet synchronous motor and the electrical angle θ of the permanent magnet synchronous motor rotor relative to the A-phase axis. e The first formula is as follows: Obtain the back electromotive force E of the α-axis of the permanent magnet synchronous motor. α .

3. The phase current reconstruction method based on a permanent magnet synchronous motor according to claim 2, characterized in that, The step of obtaining the current phase A reconstruction current value of the permanent magnet synchronous motor based on the back EMF of the α-axis of the permanent magnet synchronous motor, the A-phase reconstruction current value at the previous moment, the A-phase resistance and voltage of the permanent magnet synchronous motor, the electric angular velocity of the permanent magnet synchronous motor, the inductance of the d-axis and q-axis of the permanent magnet synchronous motor, the β-axis current of the permanent magnet synchronous motor, and the PWM control cycle includes: According to the back electromotive force E of the α axis of the permanent magnet synchronous motor α The reconstructed current value of phase A at the previous moment, i a [n-1] The A-phase resistance R of the permanent magnet synchronous motor a and voltage U a The electric angular velocity ω of the permanent magnet synchronous motor e The inductance L of the d-axis and q-axis of the permanent magnet synchronous motor d L q The current i of the β-axis of the permanent magnet synchronous motor β and PWM control period T s The second formula is adopted as follows: i a [n]=i a [n-1]+[U a -R a ×i a [n-1]+E α -ω e ×(L d -L q )×i β ]×T s / L d Obtain the current value i of phase A reconfiguration of the permanent magnet synchronous motor at the current moment. a [n]; Where n represents time and is a positive integer.

4. The phase current reconstruction method based on a permanent magnet synchronous motor according to claim 3, characterized in that, The according to the synthesized space current i s In the coordinate system formed by the d and q axes of the permanent magnet synchronous motor, the angle between the motor rotor and the d-axis is the electrical angle of the motor rotor relative to the A-phase axis, and the combined spatial current i is... s In the coordinate system formed by the α and β axes of the permanent magnet synchronous motor, the angle between the α axis and the β axis is used, and combined with the PI control mechanism, the feedback control quantity is obtained, including: According to the synthesized space current i s In the coordinate system formed by the d and q axes of the permanent magnet synchronous motor, the angle θ with the d axis is... dq The electrical angle θ of the permanent magnet synchronous motor rotor relative to the A-phase axis e The synthesized space current i s In the coordinate system formed by the α and β axes of the permanent magnet synchronous motor, the angle θ with the α axis is... αβ The angle deviation formula is used: i err =θ dq +θ e -θ αβ Obtain the angle deviation θ err ; According to the angle deviation θ err The feedback control quantity is obtained by using a PI control mechanism.

5. The phase current reconstruction method based on a permanent magnet synchronous motor according to claim 4, characterized in that, The step of adjusting the A-phase reconfiguration current value of the permanent magnet synchronous motor at the current moment according to the feedback adjustment control quantity to obtain the adjusted A-phase reconfiguration current value includes: According to the feedback adjustment control quantity E a_flt The feedback formula for calculating phase current is used: Obtain the adjusted A-phase current value i a [n] ′ .

6. A phase current reconfiguration device based on a permanent magnet synchronous motor, characterized in that, include: The acquisition module is used to acquire the inductance and current of the d-axis and q-axis of the permanent magnet synchronous motor, the electric angular velocity of the permanent magnet synchronous motor, the rotor flux linkage of the permanent magnet synchronous motor, and the electric angle of the rotor of the permanent magnet synchronous motor relative to the A-phase axis. The processing module is used to obtain the back electromotive force of the permanent magnet synchronous motor α axis based on the inductance and current of the d-axis and q-axis of the permanent magnet synchronous motor, the electric angular velocity of the permanent magnet synchronous motor, the rotor flux linkage of the permanent magnet synchronous motor, and the electric angle of the rotor of the permanent magnet synchronous motor relative to the A-phase axis. The acquisition module is also used to acquire the A-phase reconstructed current value at the previous moment, the A-phase resistance and voltage of the permanent magnet synchronous motor, the β-axis current of the permanent magnet synchronous motor, and the PWM control cycle. The processing module is further configured to obtain the current A-phase reconstructed current value of the permanent magnet synchronous motor based on the back EMF of the α-axis of the permanent magnet synchronous motor, the A-phase reconstructed current value at the previous moment, the A-phase resistance and voltage of the permanent magnet synchronous motor, the electric angular velocity of the permanent magnet synchronous motor, the inductance of the d-axis and q-axis of the permanent magnet synchronous motor, the current of the β-axis of the permanent magnet synchronous motor, and the PWM control cycle. The feedback module is used to calculate the synthesized space current i. s In the coordinate system formed by the d and q axes of the permanent magnet synchronous motor, the angle between the motor rotor and the d-axis is the electrical angle of the motor rotor relative to the A-phase axis, and the combined spatial current i is... s In the coordinate system formed by the α and β axes of the permanent magnet synchronous motor, the angle between the α axis and the β axis is obtained, and the feedback regulation control quantity is obtained in combination with the PI regulation mechanism. The processing module is further configured to adjust the A-phase reconfiguration current value of the permanent magnet synchronous motor at the current moment according to the feedback adjustment control quantity, so as to obtain the adjusted A-phase reconfiguration current value.

7. The phase current reconstruction device based on a permanent magnet synchronous motor according to claim 6, characterized in that, The processing module is specifically used for: Based on the obtained inductance L of the d-axis and q-axis of the permanent magnet synchronous motor d L q and current i d i q The electric angular velocity ω of the permanent magnet synchronous motor e The rotor flux linkage of the permanent magnet synchronous motor and the electrical angle θ of the permanent magnet synchronous motor rotor relative to the A-phase axis. e The first formula is as follows: Obtain the back electromotive force E of the α-axis of the permanent magnet synchronous motor. α .

8. The phase current reconstruction device based on a permanent magnet synchronous motor according to claim 7, characterized in that, The processing module is specifically used for: According to the back electromotive force E of the α axis of the permanent magnet synchronous motor α The reconstructed current value of phase A at the previous moment, i a [n-1] The A-phase resistance R of the permanent magnet synchronous motor a and voltage U a The electric angular velocity ω of the permanent magnet synchronous motor e The inductance L of the d-axis and q-axis of the permanent magnet synchronous motor d L q The current i of the β-axis of the permanent magnet synchronous motor β and PWM control period T s The second formula is adopted as follows: i a [n]=i a [n-1]+[U a -R a ×i a [n-1]+E α -ω e ×(L d -L q )×i β ]×T s / L d Obtain the current value i of phase A reconfiguration of the permanent magnet synchronous motor at the current moment. a [n]; Where n represents time and is a positive integer.

9. The phase current reconstruction device based on a permanent magnet synchronous motor according to claim 8, characterized in that, The feedback module is specifically used for: According to the synthesized space current i s In the coordinate system formed by the d and q axes of the permanent magnet synchronous motor, the angle θ with the d axis is... dq The electrical angle θ of the permanent magnet synchronous motor rotor relative to the A-phase axis e The synthesized space current i s In the coordinate system formed by the α and β axes of the permanent magnet synchronous motor, the angle θ with the α axis is... αβ The angle deviation formula is used: i err =θ dq +θ e -θ αβ Obtain the angle deviation θ err ; According to the angle deviation θ err The feedback control quantity is obtained by using a PI control mechanism.

10. The phase current reconstruction device based on a permanent magnet synchronous motor according to claim 9, characterized in that, The processing module is further specifically used for: According to the feedback adjustment control quantity E a_flt The feedback formula for calculating phase current is used: Obtain the adjusted A-phase current value i a [n] ′ .

11. A car, characterized in that, include: Permanent magnet synchronous motors and motor controllers; The motor controller is used to execute the phase current reconstruction method based on a permanent magnet synchronous motor as described in any one of claims 1 to 5.

12. A readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the phase current reconstruction method based on a permanent magnet synchronous motor as described in any one of claims 1 to 5.

13. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the phase current reconfiguration method based on a permanent magnet synchronous motor as described in any one of claims 1 to 5.

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