CN109921708B - Stator winding unbalanced power control method based on double three-phase permanent magnet motor distributed torque adjustment - Google Patents

Abstract

The invention discloses a stator winding unbalanced power control method based on double three-phase permanent magnet motor distributed torque regulation, which is realized based on a DSP chip and comprises the following steps: (1) sampling stator current, direct-current bus voltage, rotor angle and rotating speed; (2) establishing a magnetic field in a fixed direction, and performing initial positioning on a rotor; (3) observing double-stator winding flux linkage; (4) identifying mutual inductance values of the double three-phase motors; (5) the two sets of stator winding torque containing decoupling links are independently controlled. The control method is based on torque control, torque decoupling of two sets of stator windings is carried out through the identified motor mutual inductance parameters, independent control of torque and power of the two sets of stator windings of the double three-phase motor can be achieved, and when the two sets of windings are respectively externally connected with a power supply through an inverter, rapid switching of a dual power supply charge-discharge mode and rapid adjustment of output power can be achieved.

Description

Stator winding unbalanced power control method based on double three-phase permanent magnet motor distributed torque adjustment

Technical Field

The invention belongs to the technical field of motor control, and relates to a stator winding unbalanced power control method based on double three-phase permanent magnet motor distributed torque regulation.

Background

With the increasing severity of the problems caused by the petroleum energy crisis and traffic pollution, the demand for traffic electrification is more and more strong, and the improvement of the power and efficiency of the electrified transportation means is an important way to enhance the market competitiveness and popularize the market, the improvement of the performance of the power transmission system is one of the keys, and the power transmission system of the electric transportation means such as the electric automobile mainly comprises an electric driving system and a power supply system.

The traditional electric drive system is mainly a three-phase system, and practical researches in recent years show that after the number of motor phases becomes variable in system design, the electric drive system brings a plurality of characteristics superior to the three-phase system to the control and structure of the motor. The multi-phase motor has the advantages of small torque pulsation, high redundancy, high reliability and the like, is an important way for realizing high-power transmission at present, and has excellent application prospect in the fields of aviation, ship propulsion, electric vehicles and the like. At present, an asymmetric double-three-phase system is one of the most promising structures in a multi-phase system, and the stator side of the system is provided with two sets of three-phase windings, so that the motor driving can be realized by two sets of three-phase inverters; meanwhile, the interior of the motor can be equivalent to a symmetric twelve-phase system, so that the influence of harmonic magnetic potential and current is smaller.

The performance of a power supply system also influences the efficiency, the cruising ability, the dynamic response and other aspects of the power transmission system, a dual-power hybrid energy storage structure adopting a battery and a super capacitor is a main scheme for optimizing the performance of the current power supply system, the structure makes up the defect of a single energy storage mode by utilizing the complementary characteristics of energy storage modes such as a power type mode, an energy type mode and the like, and has unique advantages in the field of new energy. At present, a plurality of passive structures are applied in a power transmission system to directly connect the two in parallel, so that the cost is low but the energy utilization range of a super capacitor is limited; an active structure formed by connecting two energy storage elements by using a discrete bidirectional DC-DC converter has the advantages of easy modularization, independent control of each unit and the like, but the system efficiency is reduced and the system cost is increased by adding the bidirectional DC-DC converter. The integrated system formed by the separated bus type double three-phase motor driving system and the composite power supply is a novel power transmission system scheme, the separated bus structure can further increase the control freedom degree of the system, the composite power supply can be formed by two sets of independent power supplies, direct power control is realized through the motor, a DC-DC converter is not needed any more, the system combines the advantages of a multi-phase electric driving system and a hybrid energy storage power supply system, and the integrated design of the power transmission system is realized.

In order to realize the hybrid energy storage control in the power transmission system, two sets of stator windings must work in a power unbalanced state, and the charge-discharge mode switching of the energy storage element needs to be realized by changing the power flow direction of the stator windings. Because the torque distribution of the two stator windings determines the power distribution, the realization of the torque distribution control of the double windings of the double three-phase motor can exert the power management capability of a double three-phase system, and the unbalanced power control of the double windings of the double three-phase motor has important significance and practical application value for the control of an integrated power transmission system.

Disclosure of Invention

In view of the above, the invention provides a stator winding unbalanced power control method based on double three-phase permanent magnet motor distributed torque regulation, and realizes control of total torque and power distribution of two sets of windings.

A stator winding unbalanced power control method based on double three-phase permanent magnet motor distributed torque regulation comprises the following steps that the double three-phase permanent magnet motor is provided with two sets of stator windings L1 and L2, and the stator windings L1 and L2 are respectively driven by two inverters N1 and N2;

(1) three-phase stator current I on stator winding L1 is collected by Hall sensor_A、I_B、I_CAnd three-phase stator current I on stator winding L2_D、I_E、I_FAcquiring the DC bus voltage V of the inverter N1 by using a voltage sensor_dc1And the dc bus voltage V of the inverter N2_dc2Acquiring a rotor position angle theta and a rotating speed omega of the motor by using a photoelectric encoder;

(2) estimation of the three-phase stator voltage U at the stator winding L1_A、U_B、U_CAnd three-phase stator voltage U across stator winding L2_D、U_E、U_F；

(3) For three-phase stator current I_A、I_B、I_CCLARK conversion is carried out to obtain a corresponding current component I under an αβ coordinate system_1αAnd I_1βFor three-phase stator current I_D、I_E、I_FCLARK conversion is carried out to obtain a corresponding current component I under an αβ coordinate system_2αAnd I_2βFor three-phase stator voltage U_A、U_B、U_CCLARK conversion is carried out to obtain a corresponding voltage component U under αβ coordinate system_1αAnd U_1βFor three-phase stator voltage U_D、U_E、U_FCLARK conversion is carried out to obtain a corresponding voltage component U under αβ coordinate system_2αAnd U_2β；

(4) Calculating the flux linkage component psi of the stator winding L1 under the αβ coordinate system according to the result of the step (3)_1αAnd psi_1βAnd the corresponding flux linkage component psi of the stator winding L2 under the αβ coordinate system_2αAnd psi_2β；

(5) For flux linkage component psi_1αAnd psi_1βCarrying out PARK transformation to obtain corresponding flux linkage component psi under dq coordinate system_1dAnd psi_1qFor flux linkage component psi_2αAnd psi_2βCarrying out PARK transformation to obtain corresponding flux linkage component psi under dq coordinate system_2dAnd psi_2qFor current component I_1αAnd I_1βObtaining corresponding current component I under dq coordinate system by performing PARK conversion_1dAnd I_1qFor current component I_2αAnd I_2βObtaining corresponding current component I under dq coordinate system by performing PARK conversion_2dAnd I_2qFurther calculating the mutual inductance value L in the running process of the motor_qq；

(6) The given rotation speed command value omega^*Subtracting the difference value of the motor rotating speed omega, and obtaining the total torque instruction value T of the motor after PI regulation_e ^*And distributing and calculating the torque command values to obtain torque command values T corresponding to two sets of stator windings L1 and L2_e1 ^*And T_e2 ^*；

(7) The corresponding torque T of the two sets of stator windings L1 and L2 is obtained through calculation_e1And T_e2Let T be_e1 ^*And T_e2 ^*Subtract T respectively_e1And T_e2The difference value of the torque angle is regulated by PI to obtain a corresponding torque angle command value delta theta₁And Δ θ₂；

(8) The flux linkage angle theta corresponding to the two sets of stator windings L1 and L2 is obtained through calculation₁And theta₂And further combining the torque angle command value delta theta₁And Δ θ₂Calculating a flux linkage command value psi corresponding to the stator winding L1 in the dq coordinate system_1d ^*And psi_1q ^*And the corresponding flux linkage command value psi of the stator winding L2 in the dq coordinate system_2d ^*And psi_2q ^*；

(9) According to mutual inductance value L_qqAnd flux linkage command value psi_1q ^*And psi_2q ^*Flux linkage decoupling compensation quantity delta psi corresponding to two sets of stator windings L1 and L2 is obtained through calculation_1cAnd delta phi_2cTo make psi_1q ^*And psi_2q ^*Respectively with Δ ψ_1cAnd delta phi_2cAfter summation, calculating through inverse synchronous coordinate transformation to obtain a flux linkage command value psi corresponding to the stator winding L1 in a αβ coordinate system_1α ^*And psi_1β ^*And the corresponding flux linkage command value psi of the stator winding L2 under the αβ coordinate system_2α ^*And psi_2β ^*；

(10) According to flux linkage command value psi_1α ^*、ψ_1β ^*、ψ_2α ^*And psi_2β ^*Calculating to obtain a voltage command value V corresponding to the stator winding L1 under a αβ coordinate system_1α ^*And V_1β ^*And the voltage command value V corresponding to the stator winding L2 under the αβ coordinate system_2α ^*And V_2β ^*And further according to the voltage command value V_1α ^*、V_1β ^*、V_2α ^*And V_2β ^*Two sets of PWM signals (six paths in total) are generated by a space vector modulation algorithm to perform switching control on the power switching devices in the inverters N1 and N2, respectively.

Further, the three-phase stator voltage U in the step (2)_A、U_B、U_CRespectively, a DC bus voltage V_dc1The product of the duty ratios of the upper bridge arm devices of the corresponding phases of the inverter N1 in the previous period is three-phase fixedSub-voltage U_D、U_E、U_FRespectively, a DC bus voltage V_dc2And the product of the duty ratios of the upper bridge arm devices corresponds to the inverter N2 in the previous period.

Further, the flux linkage component ψ is calculated in the step (4) by the following equation_1α、ψ_1β、ψ_2αAnd psi_2β；

Wherein: psi_fThe permanent magnet flux linkage value of the motor, R is the stator winding resistance value of the motor, and t represents the moment.

Further, in the step (5), the mutual inductance value L is calculated by the following equation_qq；

Wherein: l is_qIs the self-inductance value of the motor winding.

Further, in the step (6), the torque command value T is calculated by the following formula distribution_e1 ^*And T_e2 ^*；

Wherein: d is torque distribution ratio and D is equal to P₁/P_M，P₁For the output active power of stator winding L1, P_MThe total output active power of the motor.

Further, in the step (7), the torque T is calculated by the following equation_e1And T_e2；

Wherein: n is the pole pair number, psi, of the motor_fIs the permanent magnet flux linkage value of the motor.

Further, the method can be used for preparing a novel materialIn the step (8), the flux linkage angle θ is calculated by the following equation₁And theta₂；

Further, in the step (8), the flux linkage command value ψ is calculated by the following equation_1d ^*、ψ_1q ^*、ψ_2d ^*And psi_2q ^*；

Wherein: phi₁| and | ψ₂And L is the given flux linkage amplitude corresponding to the two sets of stator windings L1 and L2 respectively.

Further, the flux linkage decoupling compensation amount Δ ψ is calculated in the step (9) by the following equation_1cAnd delta phi_2c；

Wherein: l is_qIs the self-inductance value of the motor winding.

Further, in the step (9), the flux linkage command value ψ is calculated by the following equation_1α ^*、ψ_1β ^*、ψ_2α ^*And psi_2β ^*；

Further, in the step (10), the voltage command value V is calculated by the following equation_1α ^*、V_1β ^*、V_2α ^*And V_2β ^*；

Wherein: r is the resistance value of the stator winding of the motor, and delta T is the switching period of a power switching device in the inverter.

The invention provides a double-stator winding distributed torque control scheme of a double-three-phase permanent magnet motor, which is firstly determined to be applied to a double-three-phase permanent magnet motor system, and aims to realize the distribution control of active power on double-stator windings on the premise of realizing the total torque of the motor, so that the double-three-phase motor has energy management capacity outside mechanical output. Therefore, the control method is based on torque control, torque decoupling of the two sets of stator windings is carried out through the identified motor mutual inductance parameters, independent control of torque and power of the two sets of stator windings of the double three-phase motor can be achieved, and when the two sets of windings are respectively externally connected with a power supply through an inverter, rapid switching of a dual power supply charge-discharge mode and rapid adjustment of output power can be achieved. Compared with the existing double three-phase motor torque control technology, the control method of the invention completes double-target control of mechanical torque output and winding power distribution.

Drawings

Fig. 1 is a schematic structural diagram of a power transmission system with power integration of hybrid energy storage and a double three-phase motor.

Fig. 2(a) is a block diagram showing the overall structure of the control method of the present invention.

Fig. 2(b) is a control structure block diagram of the voltage vector calculation and decoupling compensation link.

Fig. 3 is a circuit diagram of load current detection.

Fig. 4 is a circuit diagram of the switching tube driving circuit.

Fig. 5 is a schematic diagram of the control effect of the distributed torque signals of the double three-phase motor.

FIG. 6 is a schematic diagram illustrating the effect of the related signals under the switching of multiple driving modes by applying the distributed torque control method of the present invention.

Detailed Description

In order to more specifically describe the present invention, the following detailed description is provided for the technical solution of the present invention with reference to the accompanying drawings and the specific embodiments.

To realize the unbalanced power control of the stator winding based on the torque regulation of the double three-phase permanent magnet motor, the key point is that the control of the torques at two sides does not interfere with each other, and two sets of torques of the double three-phase motor can be expressed as follows:

in the formula: t is_e1And T_e2Torque, psi, generated for the first and second sets of three-phase windings, respectively_1qAnd psi_2qThe q-axis flux linkage value psi of the first set of three-phase winding and the second set of three-phase winding under the three-phase rotating coordinate system_fIs the permanent magnet flux linkage value, L_qIs the self-inductance value of the three-phase winding, L_qqThe mutual inductance value between the two sets of three-phase windings is shown.

The torque generated by each set of three-phase winding in the formula (1) is related to the flux linkage of the two sets of windings, and the torque generated by the other set of windings is required to be controlled independently without influencing the torque generated by any one of the three sets of three-phase windings, namely the torque generated by the three sets of three-phase windings is realized by the cooperation of the two sets of three-phase windings, namely the decoupling control of the flux linkage.

The invention aims to provide a distributed torque control method for double windings of a double three-phase motor, which simultaneously realizes the control of total torque and power distribution of two sets of windings and is realized by the following technical scheme:

step (1): and sampling stator current, direct-current bus voltage, rotor angle and rotating speed.

1.1 the feedback value of the first three-phase current of the double three-phase permanent magnet motor sequentially passes through the Hall sensor, the sampling signal conditioning circuit and the analog-to-digital conversion circuit to enter the DSP chip, wherein I is respectively_A、I_B、I_C. The feedback value of the second three-phase current of the double three-phase permanent magnet motor sequentially passes through the Hall sensor and the sampling signal conditioning circuit to enter the DSP chip, namely I_D、I_E、I_F。

1.2 sampling the DC bus voltage V of the first three-phase inverter by using a DC voltage sensor_dc1And a second three-phase inverter DC bus voltage V_dc2。

1.3 sampling the rotor position signal by adopting a multi-Mochuan incremental photoelectric encoder, sending the encoder output signal into an EQEP unit of a DSP28335 for processing and counting to obtain a motor rotor position signal theta and a rotating speed signal omega.

Step (2): and establishing a magnetic field in a fixed direction, and performing initial positioning on the rotor.

Switching devices of a DEF phase three-phase converter are closed, the A phase target current is set as a rotor positioning current (preset, 0.5-2A), the B, C phase target current is set as 0A, and the ABC phase current feedback value I obtained in the step 1.1 is set as_A、I_B、I_CFeeding the target current to a PI regulator according to F(s) ═ K_p+K_iS, wherein K_p＝0.1，K_iAnd outputting the voltage vector in a mode of 0.4, and sending the voltage vector to a space vector pulse width modulator (SVM) module in the DSP chip.

Wherein: v_outIs a voltage vector, V_dc1Is the DC bus voltage of the first three-phase inverter, T_pTo generate a duty cycle.

And (3): and (5) observing flux linkage of the double stator windings.

In the DSP, the six-phase voltage vectors output from the two sets of stator windings and the six-phase current feedback value in the DSP are subjected to three-phase CLARK conversion on the voltage and the current of the ABC phase winding and the DEF phase winding respectively to obtain two-phase current values and two-phase voltage values under two sets of stator winding static coordinate systems, wherein the voltage values are respectively as follows: u shape_1α，U_1βAnd U_2α，U_2βThe current values are respectively: i is_1α，I_1βAnd I_2α，I_2β。

And respectively calculating flux linkage values of the two sets of stator windings according to the voltage vectors on the two sets of stator windings.

In the formula, #_fIs the flux linkage value of the permanent magnet, R is the resistance value of the stator winding, U_1α、U_2α、U_1β、U_2βIs the coordinate of the voltage vector under the α - β coordinate system, I_1α、I_2α、I_1β、I_2βIs the coordinate of the current vector in the α - β coordinate system, psi_1α、ψ_2α、ψ_1β、ψ_2βThe coordinates of the flux linkage vector in the α - β coordinate system.

And (4): the mutual inductance value observation of the double three-phase motor is realized according to the following steps.

4.1 the value of flux linkage psi obtained in step (3)_1α、ψ_2α、ψ_1β、ψ_2βSum current value I_1α、I_2α、I_1β、I_2βAnd (2) obtaining a flux linkage value and a current value under a rotating coordinate system through double PARK transformation of theta obtained in the step (1): psi_1d、ψ_2d、ψ_1q、ψ_2qAnd I_1d、I_2d、I_1q、I_2q。

4.2 calculating the mutual inductance value L of the motor in operation according to the following formula_qq：

Wherein: l is_qThe self-inductance value of the motor winding is the intrinsic parameter of the motor.

And (5): the distributed torque control of the DSP chip on the double windings of the double three-phase permanent magnet motor is realized according to the following steps.

5.1 given rotation speed command value omega^*Sending the total torque command value T and the rotating speed signal feedback value omega obtained in the step 1.3 into a PI regulator to obtain a total torque command value T_e ^*。

5.2 according to the power distribution requirement of the two sets of stator windings, giving a torque distribution proportion value D of the two windings, and obtaining a torque command value T of the two windings according to the following formula and the total torque command value_e1 ^*、T_e2 ^*

In the formula: p₁Active power, P, for the first set of three-phase windings_MAnd outputting the total active power for the motor.

5.3 the current feedback value I obtained in the step 4.1_1q、I_2qMagnetic linkage value psi with motor permanent magnet_fAnd calculating the torque feedback values of the two windings of the double three-phase permanent magnet motor according to the following formula:

in the formula: n is the number of pole pairs of the motor.

5.4 comparing the torque command value obtained in step 5.2 with the torque feedback value obtained in step 5.3: t is_e1 ^*And T_e1、T_e2 ^*And T_e2Respectively sending the signals into two PI regulators to respectively obtain torque angle instruction values delta theta₁、Δθ₂。

5.5 the value of the flux linkage psi in step 4.1_1d，ψ_2d，ψ_1q，ψ_2qThe flux linkage angle theta of the two stator windings is obtained according to the following formula₁、θ₂：

5.6 flux linkage amplitude | psi of two sets of stator windings are respectively given₁I and | psi₂I, mixing it with theta₁、θ₂The target flux linkage command value psi is obtained by calculation according to the following formula_1d*，ψ_2d*，ψ_1q*，ψ_2q*。

5.7 conversion of step 4.1. psi_1q、ψ_2qStep 4.2L_q、L_qqψ of step 5.6_1q*，ψ_2qThe decoupling compensation is calculated according to the following formula.

5.8 decoupling compensation quantity and target instruction value psi_1qAnd Δ ψ_1c、ψ_2qAnd Δ ψ_2cRespectively summing to obtain a target flux linkage instruction value after decoupling compensation; and performing inverse synchronous coordinate transformation on the decoupled and compensated instruction values to respectively obtain flux linkage instruction values under two sets of stator winding two-phase static coordinate systems.

5.9 the voltage command value is calculated as follows.

Sending the voltage instruction value into a Space Vector Modulation (SVM) module of the DSP in the step (1), and generating six paths of pulse signals S_ABCAnd S_DEF。

And 5.10, six-phase voltage generated by the IGBT in the inverter according to the pulse signal is input to the input end of the double three-phase permanent magnet motor.

Fig. 1 shows a power transmission system with integrated hybrid energy storage and dual three-phase motor power, wherein a dual three-phase stator winding is composed of two conventional three-phase winding phases ABC and DEF, each winding is connected in a Y-shape, corresponding internal windings have an electrical angle difference of 120 ° in space, and two three-phase windings have an electrical angle difference of 30 °. The integrated power transmission system adopts a voltage source type inverter to supply power, and two sets of three-phase windings are respectively connected to two energy storage elements, namely a battery and a super capacitor, through two three-phase inverters.

The control structure of the integrated power transmission system is shown in fig. 2(a), the core technology adopted by the invention is a torque control technology, and the essence is that the electromagnetic torque generated by the stator winding is directly controlled by the magnetic field vector of the stator winding by using the analysis method of the space vector. Firstly, the output current detection current adopts a current Hall sensor with the model number of LA55-P as shown in figure 3, the resistance value of an output sampling resistor RM is configured according to the transformation ratio of the Hall sensor, so as to obtain a sampling voltage UM, A, B, C, D, E, F six-phase output current values are respectively sampled by the method, the obtained sampling voltage is input to an A/D port of a DSP after being isolated, biased, low-pass filtered and clamped, and the obtained six-path digital sampling signals are sent to the DSP, so that a corresponding six-phase current value I can be obtained_A、I_B、I_C、I_D、I_E、I_F。

Then, obtaining the rotation angle of the rotor in the sampling period through an encoder, and dividing the rotation angle by the sampling period to obtain the average rotation speed omega in the period; obtaining a speed error by subtracting the given rotating speed omega from the average rotating speed omega, and outputting a total torque instruction T after passing the obtained speed error through a PI regulator_eThe total torque instruction is proportionally distributed to two sets of stator windings through a torque reference value calculation link to respectively obtain torque instructions T of the first set of three-phase windings_e1Torque command T for three-phase windings and the second set_e2*. At the same time, the system will be based on the detected motor current I_A、I_B、I_CAnd I_D、I_E、I_FRespectively estimating actual torques T generated by the first set of three-phase windings and the second set of three-phase windings by using a torque model_e1And T_e2Then the given torque T of the first set of three-phase windings_e1A and T_e1Obtaining the torque error delta T by difference_e1Feeding a second set of three-phase windingsConstant torque T_e2A and T_e2Obtaining the torque error delta T by difference_e2。

The torque error delta T of two sets of three-phase windings_e1And Δ T_e2Respectively outputs flux linkage angle increment delta theta after passing through two PI regulators₁And Δ θ₂And the flux linkage angle increment is input to the voltage vector calculation section as shown in fig. 2 (b). Meanwhile, a stator flux linkage value can be estimated by adopting a voltage type flux linkage observation model according to the output voltage and current, and the flux linkage value is also input into a voltage vector calculation link as shown in fig. 2 (b).

First, the flux linkage angle is increased by Δ θ₁And Δ θ₂Observed flux linkage angle θ₁And theta₂And a given flux linkage magnitude command value | ψ₁ ^*I and | psi₂ ^*I get the target flux linkage vector instruction psi₁ ^*And psi₂ ^*。

The target flux linkage vector instruction is rewritable in the form of dq rotation coordinate system, #₁ ^*Can be expressed as psi_1d ^*And psi_1q ^*，ψ₂ ^*Can be expressed as psi_2q ^*And psi_2d ^*(ii) a Then decoupling the magnetic chains at two sides, wherein the decoupling amount is respectively delta psi_1cAnd delta psi_2cWill be Δ ψ_1cAnd psi_1qAddition, Δ ψ_2cAnd psi_2qAnd adding the three-phase stator windings to complete the torque decoupling control of the two sets of three-phase stator windings.

The decoupled flux linkage instruction value psi_1d*、ψ_1q*+Δψ_1c、ψ_2d*、ψ_2q*+Δψ_2cRespectively associated with the flux linkage vector psi estimated from the model_1d、ψ_1q、ψ_2d、ψ_2qAnd obtaining the error amount between the flux linkage command value and the flux linkage estimated value by calculating the difference. The rotor electrical angle theta can be obtained by multiplying the rotor rotation angle observed by the encoder by the pole pair number of the motor, the reverse Park transformation with the angle theta and theta-pi/6 is respectively carried out on flux linkage error quantities of the two sets of three-phase stator windings, and then the transformation is divided by the switching period T_sAnd calculating voltage vectors U1 and U2, and then respectively inputting the voltage vectors U1 and U2 into the space vector module to obtain twelve paths of PWM (pulse width modulation) signals.

As shown in fig. 4, the driving circuit based on the PWM signals adopts an HCPL4504 optical coupling isolation circuit and a driving chip of MIC4429 type, converts twelve paths of PWM signals into twelve paths of voltage driving signals, and finally outputs the signals to two ends of twelve IGBT gates and emitters of the six-phase inverter, respectively, thereby realizing a system control function.

Fig. 5 is a torque control experiment effect diagram of the control system, when the torque of one set of stator winding is suddenly changed, the output torque of the other set of stator winding is basically kept unchanged, and the effect of the control system is verified. Fig. 6 shows that the control mode switching effect is realized in the acceleration and deceleration process, and experiments verify that the motor can be rapidly switched among the single power supply mode, the dual power supply mode and the super capacitor charging mode.

The embodiments described above are presented to enable a person having ordinary skill in the art to make and use the invention. It will be readily apparent to those skilled in the art that various modifications to the above-described embodiments may be made, and the generic principles defined herein may be applied to other embodiments without the use of inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications to the present invention based on the disclosure of the present invention within the protection scope of the present invention.

Claims (10)

1. A stator winding unbalanced power control method based on double three-phase permanent magnet motor distributed torque regulation comprises the following steps that the double three-phase permanent magnet motor is provided with two sets of stator windings L1 and L2, and the stator windings L1 and L2 are respectively driven by two inverters N1 and N2;

(1) three-phase stator current I on stator winding L1 is collected by Hall sensor_A、I_B、I_CAnd three-phase stator current I on stator winding L2_D、I_E、I_FAcquiring the DC bus voltage V of the inverter N1 by using a voltage sensor_dc1And the dc bus voltage V of the inverter N2_dc2Acquiring a rotor position angle theta and a rotating speed omega of the motor by using a photoelectric encoder;

(2) estimation of the three-phase stator voltage U at the stator winding L1_A、U_B、U_CAnd three-phase stator voltage U across stator winding L2_D、U_E、U_F；

(3) For three-phase stator current I_A、I_B、I_CCLARK conversion is carried out to obtain a corresponding current component I under an αβ coordinate system_1αAnd I_1βFor three-phase stator current I_D、I_E、I_FCLARK conversion is carried out to obtain a corresponding current component I under an αβ coordinate system_2αAnd I_2βFor three-phase stator voltage U_A、U_B、U_CCLARK conversion is carried out to obtain a corresponding voltage component U under αβ coordinate system_1αAnd U_1βFor three-phase stator voltage U_D、U_E、U_FCLARK conversion is carried out to obtain a corresponding voltage component U under αβ coordinate system_2αAnd U_2β；

(4) Calculating the flux linkage component psi of the stator winding L1 under the αβ coordinate system according to the result of the step (3)_1αAnd psi_1βAnd the corresponding flux linkage component psi of the stator winding L2 under the αβ coordinate system_2αAnd psi_2β；

(5) For flux linkage component psi_1αAnd psi_1βCarrying out PARK transformation to obtain corresponding flux linkage component psi under dq coordinate system_1dAnd psi_1qFor flux linkage component psi_2αAnd psi_2βCarrying out PARK transformation to obtain corresponding flux linkage component psi under dq coordinate system_2dAnd psi_2qFor current component I_1αAnd I_1βObtaining corresponding current component I under dq coordinate system by performing PARK conversion_1dAnd I_1qFor current component I_2αAnd I_2βObtaining corresponding current component I under dq coordinate system by performing PARK conversion_2dAnd I_2qFurther calculating the mutual inductance value L in the running process of the motor_qq；

(6) The given rotation speed command value omega^*Subtracting the difference value of the motor rotating speed omega, and obtaining the total torque instruction value T of the motor after PI regulation_e ^*And distributing and calculating the torque command values to obtain torque command values T corresponding to two sets of stator windings L1 and L2_e1 ^*And T_e2 ^*；

(7) The corresponding torque T of the two sets of stator windings L1 and L2 is obtained through calculation_e1And T_e2Let T be_e1 ^*And T_e2 ^*Subtract T respectively_e1And T_e2The difference value of the torque angle is regulated by PI to obtain a corresponding torque angle command value delta theta₁And Δ θ₂；

(8) The flux linkage angle theta corresponding to the two sets of stator windings L1 and L2 is obtained through calculation₁And theta₂And further combining the torque angle command value delta theta₁And Δ θ₂Calculating a flux linkage command value psi corresponding to the stator winding L1 in the dq coordinate system_1d ^*And psi_1q ^*And the corresponding flux linkage command value psi of the stator winding L2 in the dq coordinate system_2d ^*And psi_2q ^*；

(9) According to mutual inductance value L_qqAnd flux linkage command value psi_1q ^*And psi_2q ^*Flux linkage decoupling compensation quantity delta psi corresponding to two sets of stator windings L1 and L2 is obtained through calculation_1cAnd delta phi_2cTo make psi_1q ^*And psi_2q ^*Respectively with Δ ψ_1cAnd delta phi_2cAfter summation, calculating through inverse synchronous coordinate transformation to obtain a flux linkage command value psi corresponding to the stator winding L1 in a αβ coordinate system_1α ^*And psi_1β ^*And the corresponding flux linkage command value psi of the stator winding L2 under the αβ coordinate system_2α ^*And psi_2β ^*；

(10) According to flux linkage command value psi_1α ^*、ψ_1β ^*、ψ_2α ^*And psi_2β ^*Calculating to obtain a voltage command value V corresponding to the stator winding L1 under a αβ coordinate system_1α ^*And V_1β ^*And the voltage command value V corresponding to the stator winding L2 under the αβ coordinate system_2α ^*And V_2β ^*And further according to the voltage command value V_1α ^*、V_1β ^*、V_2α ^*And V_2β ^*Two sets of PWM signals are generated by a space vector modulation algorithm for switching control of the power switching devices in the inverters N1 and N2, respectively.

2. The stator winding unbalanced power control method of claim 1, wherein: in the step (4), the flux linkage component ψ is calculated by the following equation_1α、ψ_1β、ψ_2αAnd psi_2β；

Wherein: psi_fThe permanent magnet flux linkage value of the motor, R is the stator winding resistance value of the motor, and t represents the moment.

3. The stator winding unbalanced power control method of claim 1, wherein: in the step (5), the mutual inductance value L is calculated by the following equation_qq；

Wherein: l is_qIs the self-inductance value of the motor winding.

4. The method of claim 1, wherein the step of controlling the imbalance power of the stator windings comprises: in the step (6), the torque command value T is calculated by the following formula_e1 ^*And T_e2 ^*；

Wherein: d is torque distribution ratio and D is equal to P₁/P_M，P₁For the output active power of stator winding L1, P_MThe total output active power of the motor.

5. The stator winding unbalanced power control method of claim 1, wherein: in the step (7), the torque T is calculated by the following equation_e1And T_e2；

Wherein: n is the pole pair number, psi, of the motor_fIs the permanent magnet flux linkage value of the motor.

6. The stator winding unbalanced power control method of claim 1, wherein: in the step (8), the flux linkage angle θ is calculated by the following equation₁And theta₂；

7. The stator winding unbalanced power control method of claim 1, wherein: in the step (8), the flux linkage command value ψ is calculated by the following equation_1d ^*、ψ_1q ^*、ψ_2d ^*And psi_2q ^*；

Wherein: phi₁| and | ψ₂And L is the given flux linkage amplitude corresponding to the two sets of stator windings L1 and L2 respectively.

8. The stator winding unbalanced power control method of claim 1, wherein: in the step (9), the flux linkage decoupling compensation quantity delta psi is calculated by the following formula_1cAnd delta phi_2c；

Wherein: l is_qIs the self-inductance value of the motor winding.

9. The stator winding unbalanced power control method of claim 1, wherein: in the step (9), the flux linkage command value ψ is calculated by the following equation_1α ^*、ψ_1β ^*、ψ_2α ^*And psi_2β ^*；

10. The stator winding unbalanced power control method of claim 1, wherein: in the step (10), the voltage command value V is calculated by the following equation_1α ^*、V_1β ^*、V_2α ^*And V_2β ^*；

Wherein: r is the resistance value of the stator winding of the motor, and delta T is the switching period of a power switching device in the inverter.

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