A multi-winding permanent magnet motor energy storage device and converter control method thereof

Abstract

The present invention discloses a multi-winding permanent magnet motor energy storage device, including a multi-winding permanent magnet synchronous generator, the multi-winding permanent magnet synchronous generator includes a rotor and a stator winding sleeved outside the rotor, and the stator winding is repeatedly composed of N groups of three-phase permanent magnet motor stator windings, and the output end of each group of three-phase permanent magnet motor stator windings is sequentially connected to an AC / DC converter, a DC / DC converter and a bypass protection circuit. Compared with the traditional three-phase permanent magnet energy storage motor, this structure has the advantages of strong fault tolerance, high reliability, easy modularization, etc., and is an effective way to realize a high-power energy storage motor system for urban rail transit; in addition, the present invention further provides a control method for the aforementioned AC / DC converter and DC / DC converter, which breaks through the technical difficulties of multi-winding permanent magnet motor coupling control and can realize efficient control of the aforementioned multi-winding permanent magnet motor energy storage device.

Description

Technical Field

[0001] The present invention relates to the field of rail transit flywheel energy storage, in particular to an improvement of a multi-winding permanent magnet motor energy storage device, and further to a converter control method thereof. Background Art

[0002] High power density energy storage motors are important energy storage modules in flywheel energy storage systems for urban rail transit. The main function of the energy storage motor is to avoid the problem of voltage rise in the traction grid caused by instantaneous high-power load shocks in the power system during the braking process of urban rail transit, so as to ensure the safe and stable operation of urban rail transit. Permanent magnet motors are the most commonly used and ideal type of energy storage motors in flywheel energy storage systems due to their advantages such as high power density, high operating efficiency, and good dynamic and static performance. They are widely used in flywheel energy storage systems. However, with the continuous increase in load power of urban rail transit, traditional three-phase energy storage permanent magnet motors can no longer meet the needs of flywheel energy storage systems for urban rail transit. Therefore, there is an urgent need to study multi-phase energy storage permanent magnet motors.

[0003] In addition, in the field of urban rail transit applications that require high reliability, new multi-phase energy storage permanent magnet motors with strong fault tolerance and high reliability have more advantages than traditional multi-phase energy storage permanent magnet motors. Therefore, it is of great theoretical and practical significance to carry out research on new multi-winding permanent magnet motor energy storage devices with high reliability and strong redundancy. On the other hand, multi-winding permanent magnet motors are essentially different from traditional three-phase and multi-phase permanent magnet motors, and traditional converter control algorithms cannot perform high-performance control on multi-winding permanent magnet motor energy storage devices. Therefore, it is also necessary to propose a simple and efficient converter control algorithm based on the special structure and characteristics of multi-winding permanent magnet motor energy storage devices. Summary of the invention

[0004] Technical problem to be solved by the present invention: In view of the above-mentioned problems in the prior art, the present invention first provides a multi-winding permanent magnet motor energy storage device. Compared with the traditional three-phase permanent magnet energy storage motor, this structure has the advantages of strong fault tolerance, high reliability, simple structure and easy modularization, and is an effective way to realize a high-power energy storage motor system for urban rail transit; in addition, the present invention further provides a converter control method for the aforementioned multi-winding permanent magnet motor energy storage device, which breaks through the technical difficulties of multi-winding permanent magnet motor coupling control and can realize efficient control of the aforementioned multi-winding permanent magnet motor energy storage device.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A multi-winding permanent magnet motor energy storage device comprises a multi-winding permanent magnet synchronous generator, wherein the multi-winding permanent magnet synchronous generator comprises a rotor and a stator winding sleeved outside the rotor, and the stator winding is repeatedly constituted by stator windings of N groups of three-phase permanent magnet motors, and the output end of each group of three-phase permanent magnet motor stator windings is sequentially connected to an AC / DC converter and a DC / DC converter, the AC side of the AC / DC converter is connected to the output end of the corresponding three-phase permanent magnet motor stator winding, and the DC side is connected to the DC / DC converter through a capacitor, and the output ends of all DC / DC converters of the multi-winding permanent magnet synchronous generator are connected in series, and in the energy storage state, the multi-winding permanent magnet synchronous generator is used as a motor to absorb energy from a traction power grid and convert electrical energy into mechanical energy; in the energy release state, the multi-winding permanent magnet synchronous generator is used as a generator to feed energy to the traction power grid and convert mechanical energy into electrical energy.

[0007] Optionally, a bypass protection circuit is also arranged in parallel at the output end of the DC / DC converter.

[0008] In addition, the present invention further provides a converter control method for the aforementioned multi-winding permanent magnet motor energy storage device, including the steps of controlling an AC / DC converter, and the detailed steps include:

[0009] 1) Detect the motor speed ω of the multi-winding permanent magnet synchronous generator e (k) and stator current i aj (k), i bj (k);

[0010] 2) According to the command power P ref (k) and motor speed ω e (k) Calculate the q-axis command current According to the d and q axis command current at time k Calculate the d-axis and q-axis command currents at time k+2 by Lagrange transformation

[0011] 3) According to the d and q axis response current i at time k dj (k), i qj (k), d, q axis response voltage u dj (k) and u qj (k) and motor speed ω e (k), predict the d and q axis response current i at time k+1 dj (k+1), i qj (k+1);

[0012] 4) According to the d and q axis command current at time k+2 The d and q axis response current i at time k+1 dj (k+1), i qj(k+1), calculate the d and q axis voltage u at k+1 dj (k+1),u qj (k+1);

[0013] 5) The d and q axis voltages u at k+1 dj (k+1),u qj (k+1) Obtain the α and β axis voltage u through coordinate transformation αj (k+1),u βj (k+1); the α and β axis voltages u αj (k+1),u βj (k+1) are respectively input into the SVPWM modulation module to obtain the modulation signal λ; the obtained six groups of modulation signals λ are respectively used to control each group of AC / DC converters.

[0014] Optionally, in step 2), the q-axis command current is calculated The mathematical expression is as follows:

[0015]

[0016] In the above formula, is the q-axis command current, P ref (k) is the power command value, n p is the number of motor pole pairs, ψ ro is the flux linkage value of the rotor permanent magnet, ω e (k) is the motor speed, and N is the number of groups of stator windings of the multi-winding permanent magnet synchronous generator including the stator windings of the three-phase permanent magnet motor.

[0017] Optionally, in step 3), the d and q axis response currents i at time k+1 are predicted dj (k+1), i qj The mathematical expression of (k+1) is as follows:

[0018]

[0019] In the above formula, i dj (k+1), i qj (k+1) are the d-axis and q-axis response currents at time k+1, i dj (k), i qj (k) are the d-axis and q-axis response currents at time k, u dj (k) and u qj (k) are the d-axis and q-axis voltages at time k, respectively, ω e (k) is the motor speed, R o is the motor resistance, ψ ro is the flux linkage value of the rotor permanent magnet, L do , L qo is the motor d and q axis inductance, Ts is the sampling period.

[0020] Optionally, in step 4), the d and q axis voltages u at time k+1 are calculated dj (k+1),u qj The mathematical expression of (k+1) is as follows:

[0021]

[0022] In the above formula, u dj (k+1),u qj (k+1) are the d-axis and q-axis voltages at time k+1, i dj (k+1), i qj (k+1) are the d-axis and q-axis response currents at time k+1, are the d-axis and q-axis command currents at time k+2, ω e (k) is the motor speed, R o is the motor resistance, ψ ro is the flux linkage value of the rotor permanent magnet, L do , L qo is the motor d and q axis inductance, T s is the sampling period.

[0023] Optionally, the present invention further includes a step of controlling the DC / DC converter, and the detailed steps include:

[0024] S1) The actual voltage u on the DC side of the AC / DC converter in With command voltage Make the difference and input it into the PI controller to get the regulated current

[0025] S2) will regulate the current The current i in the AC / DC converter in Take the difference and get the command current at the input of the DC / DC converter

[0026] S3) The command current at the input end of the DC / DC converter Divide by the modulation signal λ to obtain the command current at the output of the DC / DC converter

[0027] S4) The command current at the output end of the DC / DC converter The response current i at the output of the DC / DC converter out The difference is input into the PI controller to obtain the command value of the DC / DC converter output voltage

[0028] S5) Set the DC / DC converter output voltage command value The actual voltage u of the DC / DC converter output terminal out Add them together and divide them by the actual voltage u at the output of the AC / DC converter in , to obtain the modulation signal λ of the DC / DC converter so as to achieve the purpose of controlling the DC / DC converter.

[0029] In addition, the present invention also provides a converter control system for a multi-winding permanent magnet motor energy storage device, including a computer device that is programmed or configured to execute the steps of the converter control method for the multi-winding permanent magnet motor energy storage device.

[0030] In addition, the present invention also provides a converter control system for a multi-winding permanent magnet motor energy storage device, including a computer device, which includes at least a memory and a microprocessor, and the memory stores a computer program programmed or configured to execute the converter control method of the multi-winding permanent magnet motor energy storage device.

[0031] In addition, the present invention also provides a computer-readable storage medium, on which is stored a computer program programmed or configured to execute the converter control method of the multi-winding permanent magnet motor energy storage device.

[0032] Compared with the prior art, the multi-winding permanent magnet motor energy storage device of the present invention has the following advantages: the stator winding of the multi-winding permanent magnet motor of the present invention is composed of N groups of three-phase permanent magnet motor stator windings, and the output end of each group of three-phase permanent magnet motor stator windings is connected to an AC / DC converter and a DC / DC converter in sequence, the AC / DC converter is used for converting alternating current and direct current, the DC / DC converter is used to stabilize the capacitor voltage between the AC / DC converter and the DC / DC converter, in the energy storage state, the multi-winding permanent magnet synchronous generator is used as a motor to absorb energy from the traction power grid and convert electrical energy into mechanical energy; in the energy release state, the multi-winding permanent magnet synchronous generator is used as a generator to feed energy to the traction power grid and convert mechanical energy into electrical energy. Compared with the traditional three-phase permanent magnet energy storage motor, it has the advantages of strong fault tolerance, high reliability, simple structure and easy modularization, and is an effective way to realize a high-power energy storage motor system for urban rail transit.

[0033] The converter control method of the multi-winding permanent magnet motor energy storage device of the present invention has the following advantages: the multi-winding permanent magnet motor is essentially different from the traditional three-phase permanent magnet motor, and the traditional converter control algorithm cannot well control the multi-winding permanent magnet motor energy storage device. The converter control method of the multi-winding permanent magnet motor energy storage device of the present invention breaks through the technical difficulties of multi-winding permanent magnet motor coupling control and can realize the decoupling control of the aforementioned multi-winding permanent magnet motor energy storage device. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 Schematic diagram of the overall structure of the multi-winding permanent magnet motor energy storage device in the first embodiment of the present invention.

[0035] Figure 2 Schematic diagram of predictive power control of an AC / DC converter in Embodiment 2 of the present invention.

[0036] Figure 3 Schematic diagram of the control principle of the DC / DC converter in the second embodiment of the present invention. DETAILED DESCRIPTION

[0037] Embodiment 1:

[0038] The following will take a multi-winding permanent magnet synchronous generator 1 with N=6 (the stator winding is composed of 6 groups of three-phase permanent magnet motor stator windings repeated) as an example to further explain the multi-winding permanent magnet motor energy storage device of the present invention in detail.

[0039] like Figure 1 As shown, the multi-winding permanent magnet motor energy storage device of this embodiment includes a multi-winding permanent magnet synchronous generator 1, which includes a rotor and a stator winding sleeved outside the rotor, and the stator winding is repeatedly composed of N groups of stator windings of three-phase permanent magnet motors, and the output end of each group of three-phase permanent magnet motor stator windings is sequentially connected to an AC / DC converter 2 and a DC / DC converter 3, the AC side of the AC / DC converter 2 is connected to the output end of the corresponding three-phase permanent magnet motor stator winding, and the DC side is connected to the DC / DC converter 3 through a capacitor, and the output ends of all DC / DC converters 3 of the multi-winding permanent magnet synchronous generator 1 are connected in series, and in the energy storage state, the multi-winding permanent magnet synchronous generator 1 is used as a motor to absorb energy from the traction power grid and convert electrical energy into mechanical energy; in the energy release state, the multi-winding permanent magnet synchronous generator 1 is used as a generator to feed energy to the traction power grid and convert mechanical energy into electrical energy.

[0040] The stator winding of the multi-winding permanent magnet synchronous generator 1 in this embodiment is composed of six stator windings of traditional three-phase permanent magnet motors, and the rotor is the same as the rotor of the traditional three-phase permanent magnet motor, which is essentially equivalent to six traditional three-phase permanent magnet motors with a common rotor. The AC / DC converter 2 is used for converting alternating current and direct current; the DC / DC converter 3 is used to stabilize the capacitor voltage between the AC / DC converter 2 and the DC / DC converter 3.

[0041] like Figure 1 As shown, in this embodiment, a bypass protection circuit 4 is also arranged in parallel at the output end of the DC / DC converter 3. The bypass protection circuit 4 is used to achieve fault isolation of a group of three-phase permanent magnet motor stator windings when a winding fault occurs in the multi-winding permanent magnet synchronous generator.

[0042] like Figure 1 As shown, the bypass protection circuit 4 is a bypass switch, which is connected in parallel with the output end of the corresponding DC / DC converter 3 through a capacitor, so as to achieve fault isolation of a group of three-phase permanent magnet motor stator windings when a winding fault occurs in the multi-winding permanent magnet synchronous generator 1.

[0043] Embodiment 2:

[0044] Based on the first embodiment, this embodiment further implements the converter control method of the multi-winding permanent magnet motor energy storage device shown in the first embodiment. In addition, the present invention further provides a converter control method of the multi-winding permanent magnet motor energy storage device, including the steps of controlling the AC / DC converter 2, such as Figure 2 The detailed steps include:

[0045] 1) Detect the motor speed ω of the multi-winding permanent magnet synchronous generator 1 e (k) and stator current i aj (k), i bj (k);

[0046] 2) According to the command power P ref (k) and motor speed ω e (k) Calculate the q-axis command current According to the d and q axis command current at time k Calculate the d-axis and q-axis command currents at time k+2 by Lagrange transformation

[0047] 3) According to the d and q axis response current i at time k dj (k), i qj (k), d, q axis response voltage u dj (k) and u qj (k) and motor speed ω e (k), predict the d and q axis response current i at time k+1 dj (k+1), i qj (k+1);

[0048] 4) According to the d and q axis command current at time k+2 The d and q axis response current i at time k+1 dj (k+1), i qj (k+1), calculate the d and q axis voltage u at k+1 dj (k+1),u qj (k+1);

[0049] 5) The d and q axis voltages u at k+1 dj (k+1),u qj(k+1) Obtain the α and β axis voltage u through coordinate transformation αj (k+1),u βj (k+1); the α and β axis voltages u αj (k+1),u βj (k+1) are respectively input into the SVPWM modulation module to obtain the modulation signal λ; the obtained six groups of modulation signals λ are respectively used to control each group of AC / DC converters 2.

[0050] In this embodiment, the q-axis command current is calculated in step 2). The mathematical expression is as follows:

[0051]

[0052] In the above formula, is the q-axis command current, P ref (k) is the power command value, n p is the number of motor pole pairs, ψ ro is the flux linkage value of the rotor permanent magnet, ω e (k) is the motor speed, and N is the number of groups of three-phase permanent magnet motor stator windings included in the stator winding of the multi-winding permanent magnet synchronous generator 1.

[0053] like Figure 2 As shown, in step 3), the d and q axis response current i at time k+1 is predicted dj (k+1), i qj The module of (k+1) is named Smith predictive controller. In step 3) of this embodiment, the d and q axis response currents i at time k+1 are predicted. dj (k+1), i qj The mathematical expression of (k+1) is as follows:

[0054]

[0055] In the above formula, i dj (k+1), i qj (k+1) are the d-axis and q-axis response currents at time k+1, i dj (k), i qj (k) are the d-axis and q-axis response currents at time k, u dj (k) and u qj (k) are the d-axis and q-axis voltages at time k, respectively, ω e (k) is the motor speed, R o is the motor resistance, ψ ro is the flux linkage value of the rotor permanent magnet, L do , L qo is the motor d and q axis inductance, T s is the sampling period.

[0056] like Figure 2 As shown, in step 4), the d and q axis voltages u at k+1 are calculated. dj (k+1),u qj The module at (k+1) is named as the predictive current controller. In step 4) of this embodiment, the d and q axis voltages u at time k+1 are calculated. dj (k+1),u qj The mathematical expression of (k+1) is as follows:

[0057]

[0058] In the above formula, u dj (k+1),u qj (k+1) are the d-axis and q-axis voltages at time k+1, i dj (k+1), i qj (k+1) are the d-axis and q-axis response currents at time k+1, are the d-axis and q-axis command currents at time k+2, ω e (k) is the motor speed, R o is the motor resistance, ψ ro is the flux linkage value of the rotor permanent magnet, L do , L qo is the motor d and q axis inductance, T s is the sampling period.

[0059] In addition, this embodiment also includes the step of controlling the DC / DC converter 3, such as Figure 3 As shown, the detailed steps include:

[0060] S1) The actual voltage u on the DC side of AC / DC converter 2 is in With command voltage Make the difference and input it into the PI controller to get the regulated current

[0061] S2) will regulate the current and the current i in the AC / DC converter 2 in Make a difference and get the command current at the input terminal 3 of the DC / DC converter

[0062] S3) The command current at the input end of the DC / DC converter 3 Divide by the modulation signal λ to obtain the command current at the output end of the DC / DC converter 3

[0063] S4) The command current at the output end of the DC / DC converter 3 The response current i at the output of the DC / DC converter 3out The difference is input into the PI controller to obtain the command value of the output voltage of DC / DC converter 3

[0064] S5) The command value of the output voltage of the DC / DC converter 3 is The actual voltage u of the output terminal of the DC / DC converter 3 out Add them together and divide them by the actual voltage u at the output of AC / DC converter 2 in , to obtain the modulation signal λ of the DC / DC converter 3 so as to achieve the purpose of controlling the DC / DC converter 3.

[0065] In addition, the present invention also provides a converter control system for a multi-winding permanent magnet motor energy storage device, including a computer device that is programmed or configured to execute the steps of the converter control method for the multi-winding permanent magnet motor energy storage device.

[0066] In addition, the present invention also provides a converter control system for a multi-winding permanent magnet motor energy storage device, including a computer device, which includes at least a memory and a microprocessor, and the memory stores a computer program programmed or configured to execute the converter control method of the multi-winding permanent magnet motor energy storage device.

[0067] In addition, the present invention also provides a computer-readable storage medium, on which is stored a computer program programmed or configured to execute the converter control method of the multi-winding permanent magnet motor energy storage device.

[0068] It should be noted that N=6 (the stator winding of the multi-winding permanent magnet synchronous generator 1 is composed of 6 groups of three-phase permanent magnet motor stator windings) is only an optional implementation scheme of the present invention. The scheme of the present invention can obviously also be applied to the situation where the stator winding of the multi-winding permanent magnet synchronous generator 1 is composed of other number of groups of three-phase permanent magnet motor stator windings.

[0069] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A converter control method for a multi-winding permanent magnet motor energy storage device, characterized in that: The multi-winding permanent magnet motor energy storage device comprises a multi-winding permanent magnet synchronous generator (1), the multi-winding permanent magnet synchronous generator (1) comprising a rotor and a stator winding sleeved outside the rotor, and the stator winding is repeatedly formed by stator windings of N groups of three-phase permanent magnet motors, and the output end of each group of three-phase permanent magnet motor stator windings is sequentially connected to an AC / DC converter (2) and a DC / DC converter (3), the AC side of the AC / DC converter (2) is connected to the output end of the corresponding three-phase permanent magnet motor stator winding, and the DC side is connected to the DC / DC converter (3) through a capacitor, and the output ends of all DC / DC converters (3) of the multi-winding permanent magnet synchronous generator (1) are connected in series, and in the energy storage state, the multi-winding permanent magnet synchronous generator (1) is used as a motor to absorb energy from the traction power grid and convert electrical energy into mechanical energy; in the energy release state, the multi-winding permanent magnet synchronous generator (1) is used as a generator to feed energy to the traction power grid and convert mechanical energy into electrical energy; The converter control method comprises the steps of controlling the AC / DC converter (2), and the detailed steps include: 1) Detecting the motor speed of a multi-winding permanent magnet synchronous generator (1) With stator current , ; 2) According to the command power and motor speed calculate q Axis command current ;according to k Moment d , q Axis command current , Calculation by Lagrange transformation Moment d , q Axis command current , ; 3) According to k Moment d , q Axis response current , , d , q Shaft response voltage , With motor speed ,predict Moment d , q Axis response current , ; 4) According to Moment d , q Axis command current , , Moment d , q Axis response current , ,calculate Moment d , q Shaft voltage , ; 5) Moment d , q Shaft voltage , Obtained by coordinate transformation , Shaft voltage , ;Will , Shaft voltage , The modulation signals λ are respectively input into the SVPWM modulation module to obtain the modulation signals λ; the obtained six groups of modulation signals λ are respectively used to control each group of AC / DC converters (2); The method also includes the step of controlling the DC / DC converter (3), and the detailed steps include: S1) The actual voltage on the DC side of the AC / DC converter (2) With command voltage Make the difference and input it into the PI controller to get the regulated current ; S2) will regulate the current and the current in the AC / DC converter (2) Take the difference and obtain the command current at the input of the DC / DC converter (3) ; S3) The command current at the input end of the DC / DC converter (3) Divide by the modulation signal λ to obtain the command current at the output end of the DC / DC converter (3) ; S4) The command current at the output end of the DC / DC converter (3) The response current at the output of the DC / DC converter (3) The difference is input into the PI controller to obtain the command value of the DC / DC converter output voltage ; S5) Sets the command value of the output voltage of the DC / DC converter (3) The actual voltage at the output of the DC / DC converter (3) Add them together and divide by the actual voltage at the output of the AC / DC converter (3) , to obtain the modulation signal λ of the DC / DC converter (3) so as to achieve the purpose of controlling the DC / DC converter (3).

2. The converter control method of the multi-winding permanent magnet motor energy storage device according to claim 1, characterized in that: Calculate in step 2) q Axis command current The mathematical expression is as follows: In the above formula, for q Axis command current, is the power command value, is the number of pole pairs of the motor, is the flux linkage value of the rotor permanent magnet, is the motor speed, N The stator winding of the multi-winding permanent magnet synchronous generator (1) includes the number of groups of three-phase permanent magnet motor stator windings.

3. The converter control method of the multi-winding permanent magnet motor energy storage device according to claim 1, characterized in that: Step 3) Prediction k+1 Moment d , q Axis response current , The mathematical expression is as follows: In the above formula, , They are Moment d , q Axis response current, , They are k Moment d , q Axis response current, , They are k Moment d , q Shaft voltage, is the motor speed, is the motor resistance, is the flux linkage value of the rotor permanent magnet, , For motor d , q Shaft inductance, is the sampling period.

4. The converter control method of the multi-winding permanent magnet motor energy storage device according to claim 1, characterized in that: Step 4) Calculate k+1 of d , q Shaft voltage , The mathematical expression is as follows: In the above formula, , They are Moment d , q Shaft voltage, , They are Moment d , q Axis response current, , They are Moment d , q Axis command current, is the motor speed, is the motor resistance, is the flux linkage value of the rotor permanent magnet, , For motor d , q Shaft inductance, is the sampling period.

5. The converter control method of the multi-winding permanent magnet motor energy storage device according to claim 1, characterized in that: A bypass protection circuit (4) is also arranged in parallel at the output end of the DC / DC converter (3).

6. A converter control system for a multi-winding permanent magnet motor energy storage device, comprising a computer device, characterized in that: The computer device is programmed or configured to execute the steps of the converter control method of the multi-winding permanent magnet motor energy storage device as claimed in any one of claims 1 to 4.

7. A converter control system for a multi-winding permanent magnet motor energy storage device, comprising a computer device, characterized in that: The computer device comprises at least a memory and a microprocessor, and the memory stores a computer program programmed or configured to execute the converter control method of the multi-winding permanent magnet motor energy storage device according to any one of claims 1 to 4.

8. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program that is programmed or configured to execute the converter control method of the multi-winding permanent magnet motor energy storage device according to any one of claims 1 to 4.

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