CN111478347B - Variable frequency transformer fault ride-through control method and circuit - Google Patents

Variable frequency transformer fault ride-through control method and circuit Download PDF

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CN111478347B
CN111478347B CN202010287207.7A CN202010287207A CN111478347B CN 111478347 B CN111478347 B CN 111478347B CN 202010287207 A CN202010287207 A CN 202010287207A CN 111478347 B CN111478347 B CN 111478347B
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stator
phase
series
rotor
phase converter
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CN111478347A (en
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卢嘉豪
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Guangdong Power Grid Co Ltd
Foshan Power Supply Bureau of Guangdong Power Grid Corp
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Guangdong Power Grid Co Ltd
Foshan Power Supply Bureau of Guangdong Power Grid Corp
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/26—Arrangements for eliminating or reducing asymmetry in polyphase networks
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/12—Circuit arrangements for ac mains or ac distribution networks for adjusting voltage in ac networks by changing a characteristic of the network load
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/24—Arrangements for preventing or reducing oscillations of power in networks
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P21/00—Arrangements or methods for the control of electric machines by vector control, e.g. by control of field orientation
    • H02P21/0003—Control strategies in general, e.g. linear type, e.g. P, PI, PID, using robust control
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P21/00—Arrangements or methods for the control of electric machines by vector control, e.g. by control of field orientation
    • H02P21/24—Vector control not involving the use of rotor position or rotor speed sensors
    • H02P21/26—Rotor flux based control
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P21/00—Arrangements or methods for the control of electric machines by vector control, e.g. by control of field orientation
    • H02P21/24—Vector control not involving the use of rotor position or rotor speed sensors
    • H02P21/28—Stator flux based control
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
    • Y02E40/50—Arrangements for eliminating or reducing asymmetry in polyphase networks

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  • Power Engineering (AREA)
  • Inverter Devices (AREA)

Abstract

The invention relates to a variable frequency transformer fault ride-through control method and a circuit, which achieve the following effects by controlling the output voltage of a stator side series three-phase converter: (1) maintaining the voltage of the direct current bus stable; (2) maintaining control capability over reactive power; (3) suppressing the negative sequence voltage of the stator; the negative sequence voltage of the rotor is suppressed by controlling the output voltage of the rotor-side series three-phase converter. Compared with the technical scheme of adopting a parallel three-phase converter and a series three-phase converter, the invention has the advantages that no new equipment is added, the voltage of the stator and the voltage of the rotor are controllable, and the fluctuation of electromagnetic torque, active power and reactive power is thoroughly inhibited; compared with the technical scheme of adopting two parallel three-phase converters and two series three-phase converters, the invention can realize the fault ride-through control of the variable frequency transformer without the parallel three-phase converters, reduces the number of the three-phase converters of the fault ride-through circuit from 4 to 2, and greatly reduces the system cost.

Description

Variable frequency transformer fault ride-through control method and circuit
Technical Field
The invention relates to the technical field of asynchronous interconnection of power grids, in particular to a fault ride-through control method and circuit of a variable-frequency transformer.
Background
With the heavy use of unbalanced loads in power systems, the possibility of voltage unbalance phenomena occurring in the transmission lines is gradually increasing. The stator winding and the rotor winding of the variable frequency transformer are respectively connected with two groups of power transmission lines, so that the voltages of the power networks on two sides of the variable frequency transformer are unbalanced.
When the three-phase voltage unbalance fault occurs on the power grids on the two sides of the variable frequency transformer, the current flowing through the variable frequency transformer is unbalanced in three phases. The interaction between unbalanced voltages and currents of three phases can cause the electromagnetic torque, active power and reactive power of the variable frequency transformer to generate the fluctuation of twice the rotating electrical angular speed of the rotor, twice the synchronous angular speed of the stator and twice the synchronous angular speed of the rotor. Fluctuations in electromagnetic torque can reduce the life of mechanical systems, and fluctuations in active and reactive power can reduce the quality of the electrical energy of electrical power systems.
The two existing technologies deal with the fault that three-phase voltage imbalance occurs simultaneously in the power grids on two sides of the variable-frequency transformer.
One technique is to use a parallel three-phase converter and a series three-phase converter. The parallel three-phase converter provides a stable power supply for the series three-phase converter, and the series three-phase converter controls the voltage unbalance on the left side. As shown in fig. 1.
Another technique is to use two parallel three-phase converters and two series three-phase converters. The parallel three-phase converters provide stable power for the two series three-phase converters, and the two three-phase converters respectively control the voltage unbalance on the left side and the right side. As shown in fig. 2.
In the first prior art, a series three-phase converter is used to solve the problem of imbalance between the left and right sides. However, because the rotor voltage cannot be controlled, the fluctuation of electromagnetic torque, active power and reactive power is not completely inhibited.
In the second prior art, two three-phase converters connected in series are used to solve the problem of imbalance between the left side and the right side. But requires a parallel three-phase converter to provide a stable power supply, resulting in a fault-ride-through circuit that is cost prohibitive.
Disclosure of Invention
The invention provides a variable frequency transformer fault ride-through control method and a variable frequency transformer fault ride-through control circuit for overcoming the defect that the prior art is difficult to thoroughly inhibit the fluctuation of electromagnetic torque, active power and reactive power and simultaneously reduces the cost of a fault ride-through circuit.
The method comprises the steps of controlling a stator side series three-phase converter and controlling a rotor side series three-phase converter;
the control method of the stator side series three-phase converter comprises the following steps:
step (1-1): stator side grid voltage u is collected by voltage sensorsgabcStator voltage usabcStator side series three-phase converter voltage uscc1abcAnd DC capacitor voltage Vdc(ii) a Stator current i is collected by using current sensorsabcAnd stator side series three-phase converter current iscc1abc。
Step (1-2): the stator-side grid voltage usgabcStator voltage usabcStator side series three-phase converter voltage uscc1abcStator current isabcAnd stator side series three-phase converter current iscc1abcTo process the stator reactive power QsStator side series three-phase converter positive sequence current direct current component
Figure BDA0002448965820000021
And negative sequence voltage DC component of stator
Figure BDA0002448965820000022
Step (1-3): the voltage V of the DC capacitordcStator reactive power QsStator side series three-phase converter positive sequence current direct current component
Figure BDA0002448965820000023
And negative sequence voltage DC component of stator
Figure BDA0002448965820000024
Processing according to a preset voltage control equation to obtain a direct-current component of a positive sequence voltage reference value of the three-phase converter connected in series at the stator side
Figure BDA0002448965820000025
Three-phase transformation connected in series with stator sideNegative sequence voltage reference value DC component of converter
Figure BDA0002448965820000026
Step (1-4): according to the positive sequence voltage reference value direct current component of the stator side series three-phase converter
Figure BDA0002448965820000027
And a stator side series three-phase converter negative sequence voltage reference value direct current component
Figure BDA0002448965820000028
Obtaining a voltage reference value of a stator side series three-phase converter under a two-phase static coordinate system
Figure BDA0002448965820000029
Step (1-5): connecting the stator side in series with the voltage reference value of the three-phase converter
Figure BDA00024489658200000210
Obtaining a control signal S of a stator side series three-phase converter switch through space vector modulation1、S2、S3；
The control method of the rotor side series three-phase converter comprises the following steps:
step (2-1): collecting rotor side grid voltage urgabcAnd rotor voltage urabc；
Step (2-2): according to the rotor-side grid voltage urgabcAnd rotor voltage urabcObtaining the positive sequence voltage DC component of the rotor side power grid
Figure BDA00024489658200000211
Direct component of rotor positive sequence voltage
Figure BDA00024489658200000212
And negative sequence voltage DC component of rotor
Figure BDA00024489658200000213
Step (2-3): the positive sequence voltage direct current component of the rotor side power grid
Figure BDA00024489658200000214
Direct component of rotor positive sequence voltage
Figure BDA00024489658200000215
And negative sequence voltage DC component of rotor
Figure BDA00024489658200000216
Processing according to a preset voltage control equation to obtain a direct-current component of a positive sequence voltage reference value of the rotor-side series three-phase converter
Figure BDA00024489658200000217
And rotor side series three-phase converter negative sequence voltage reference value direct current component
Figure BDA00024489658200000218
Step (2-4): according to the positive sequence voltage reference value direct current component of the rotor side series three-phase converter
Figure BDA0002448965820000031
And rotor side series three-phase converter negative sequence voltage reference value direct current component
Figure BDA0002448965820000032
Obtaining a voltage reference value of a rotor-side series three-phase converter under a two-phase static coordinate system
Figure BDA0002448965820000033
Step (2-5): connecting the rotor side in series with the voltage reference value of the three-phase converter
Figure BDA0002448965820000034
Obtaining a control signal S of a three-phase converter switch connected in series at the rotor side through space vector modulation4、S5、S6。
Preferably, the step (1-2) is specifically:
stator voltage usabcAnd stator current isabcObtaining the stator reactive power Q through power calculation processings(ii) a Connecting stator side in series with three-phase converter voltage uscc1abcStator side series three-phase converter current iscc1abcStator-side grid voltage usgabcAnd stator voltage usabcRespectively carrying out conversion processing from three-phase static to two-phase static coordinates to obtain a voltage vector u of a stator-side series three-phase converter under a two-phase static coordinate systemscc1αβStator side series three-phase converter current vector iscc1αβStator-side grid voltage vector usgαβAnd stator voltage vector usαβ；
Connecting stator side in series with three-phase converter voltage vector uscc1αβStator side series three-phase converter current vector iscc1αβStator-side grid voltage vector usgαβAnd stator voltage vector usαβRespectively carrying out positive and negative sequence separation treatment to obtain a positive sequence voltage vector u of the stator side series three-phase converterscc1αβ+Stator side series three-phase converter positive sequence current vector iscc1αβ+Negative sequence voltage vector u of stator side power gridsgαβ-And stator negative sequence voltage vector usαβ-。
Connecting the stator side in series with the positive sequence voltage vector u of the three-phase converterscc1αβ+And stator side grid negative sequence voltage vector usgαβ-Respectively calculating and processing phase angles to obtain positive sequence phase thetasg+And negative sequence phase thetasg-；
Connecting stator side in series with three-phase converter positive sequence current vector iscc1αβ+And stator negative sequence voltage vector usαβ-Respectively carrying out conversion treatment from two-phase static to two-phase rotating coordinates to obtain positive sequence current direct-current components of the stator-side series three-phase converter under a synchronous rotating coordinate system
Figure BDA0002448965820000035
And negative sequence voltage DC component of stator
Figure BDA0002448965820000036
Preferably, the preset voltage control equation in step (1-3) is as follows:
Figure BDA0002448965820000037
wherein, Kp1And Ki1The proportional coefficient and the integral coefficient of the direct current capacitor voltage controller are respectively; kp2And Ki2Respectively are a proportional coefficient and an integral coefficient of the stator reactive power controller; kp3And Ki3Proportional coefficients and integral coefficients of a d-axis positive sequence current controller of the three-phase converter connected in series at the stator side are respectively; kp4And Ki4Proportional coefficients and integral coefficients of a q-axis positive sequence current controller of a stator side series three-phase converter are respectively obtained; kp5And Ki5Proportional coefficient and integral coefficient of the stator d-axis negative sequence voltage controller are respectively; kp6And Ki6Proportional and integral coefficients of the stator q-axis negative sequence voltage controller are provided.
s represents the laplace operator and is,
Figure BDA0002448965820000041
is composed of
Figure BDA0002448965820000042
The d-axis component of (a) is,
Figure BDA0002448965820000043
is composed of
Figure BDA0002448965820000044
The q-axis component of (a) is,
Figure BDA0002448965820000045
is composed of
Figure BDA0002448965820000046
The d-axis component of (a) is,
Figure BDA0002448965820000047
is composed of
Figure BDA0002448965820000048
The q-axis component of (a) is,
Figure BDA0002448965820000049
is composed of
Figure BDA00024489658200000410
The d-axis component of (a) is,
Figure BDA00024489658200000411
is composed of
Figure BDA00024489658200000412
The q-axis component of (a) is,
Figure BDA00024489658200000413
is composed of
Figure BDA00024489658200000414
The d-axis component of (a) is,
Figure BDA00024489658200000415
is composed of
Figure BDA00024489658200000416
The q-axis component of (a) is,
Figure BDA00024489658200000417
represents a reference value of the dc bus voltage,
Figure BDA00024489658200000418
representing a reactive power reference value.
Preferably, the steps (1-4) are specifically:
connecting the positive sequence voltage reference value DC component of the three-phase converter in series on the stator side
Figure BDA00024489658200000419
Negative sequence voltage parameter of three-phase converter connected in series with stator sideDC component of reference value
Figure BDA00024489658200000420
Respectively carrying out conversion treatment from two-phase rotation to two-phase static coordinates to obtain a positive sequence voltage reference value of a stator side series three-phase converter under a two-phase static coordinate system
Figure BDA00024489658200000421
Negative sequence voltage reference value of three-phase converter connected in series with stator side
Figure BDA00024489658200000422
Connecting the stator side in series with the positive sequence voltage reference value of the three-phase converter
Figure BDA00024489658200000423
Negative sequence voltage reference value of three-phase converter connected in series with stator side
Figure BDA00024489658200000424
Adding to obtain the voltage reference value of the stator side series three-phase converter under the two-phase static coordinate system
Figure BDA00024489658200000425
Preferably, the step (2-2) is specifically:
the rotor-side grid voltage urgabcAnd rotor voltage urabcRespectively carrying out conversion processing from three-phase static coordinates to two-phase static coordinates to obtain a rotor side power grid voltage vector u under a two-phase static coordinate systemrgαβAnd rotor voltage vector urαβ；
The rotor side grid voltage vector urgαβAnd rotor voltage vector urαβRespectively carrying out positive and negative sequence separation treatment to obtain a rotor side power grid positive sequence voltage vector urgαβ+Negative sequence voltage vector u of rotor side power gridrgαβ-Positive sequence voltage vector u of rotorrαβ+And rotor negative sequence voltage vector urαβ-。
The positive sequence voltage vector u of the rotor side power gridrgαβ+And rotor side grid negative sequence voltage vector urgαβ-Respectively calculating and processing phase angles to obtain positive sequence phase thetarg+And negative sequence phase thetarg-；
The positive sequence voltage vector u of the rotor side power gridrgαβ+Positive sequence voltage vector u of rotorrαβ+And rotor negative sequence voltage vector urαβ-Respectively carrying out conversion treatment from two-phase static to two-phase rotating coordinates to obtain the positive sequence voltage direct-current component of the rotor side power grid under the synchronous rotating coordinate system
Figure BDA00024489658200000426
Direct component of rotor positive sequence voltage
Figure BDA00024489658200000427
And negative sequence voltage DC component of rotor
Figure BDA00024489658200000428
Preferably, the preset voltage control equation in step (2-3) is as follows:
Figure BDA0002448965820000051
wherein, Kp7And Ki7Proportional coefficients and integral coefficients of the rotor d-axis positive sequence voltage controller are respectively; kp8And Ki8Proportional coefficients and integral coefficients of a rotor q-axis positive sequence voltage controller are respectively; kp9And Ki9Proportional coefficient and integral coefficient of the rotor d-axis negative sequence voltage controller are respectively; kp10And Ki10Proportional coefficients and integral coefficients of a rotor q-axis negative sequence voltage controller are respectively provided;
s represents the laplace operator and is,
Figure BDA0002448965820000052
is composed of
Figure BDA0002448965820000053
The d-axis component of (a) is,
Figure BDA0002448965820000054
to represent
Figure BDA0002448965820000055
The q-axis component of (a) is,
Figure BDA0002448965820000056
to represent
Figure BDA0002448965820000057
The d-axis component of (a) is,
Figure BDA0002448965820000058
to represent
Figure BDA0002448965820000059
The q-axis component of (a) is,
Figure BDA00024489658200000510
to represent
Figure BDA00024489658200000511
The d-axis component of (a) is,
Figure BDA00024489658200000512
to represent
Figure BDA00024489658200000513
The q-axis component of (a) is,
Figure BDA00024489658200000514
to represent
Figure BDA00024489658200000515
The d-axis component of (a) is,
Figure BDA00024489658200000516
to represent
Figure BDA00024489658200000517
The q-axis component of (a) is,
Figure BDA00024489658200000518
to represent
Figure BDA00024489658200000519
The d-axis component of (a) is,
Figure BDA00024489658200000520
to represent
Figure BDA00024489658200000521
Q-axis component of (a).
Preferably, the step (2-4) is specifically:
connecting the rotor side in series with the positive sequence voltage reference value direct current component of the three-phase converter
Figure BDA00024489658200000522
And rotor side series three-phase converter negative sequence voltage reference value direct current component
Figure BDA00024489658200000523
Respectively carrying out conversion treatment from two-phase rotation to two-phase static coordinates to obtain a positive sequence voltage reference value of a rotor side series three-phase converter under a two-phase static coordinate system
Figure BDA00024489658200000524
Negative sequence voltage reference value of three-phase converter connected in series with rotor side
Figure BDA00024489658200000525
Connecting the rotor side in series with the positive sequence voltage reference value of the three-phase converter
Figure BDA00024489658200000526
Negative sequence voltage reference value of three-phase converter connected in series with rotor side
Figure BDA00024489658200000527
Adding to obtain the voltage reference value of the rotor side series three-phase converter under the two-phase static coordinate system
Figure BDA00024489658200000528
The invention relates to a fault ride-through circuit of a variable frequency transformer, which comprises: the system comprises a stator side power grid, a stator side series three-phase transformer, a stator side series three-phase converter, a control circuit, an H-bridge converter, a rotor side series three-phase transformer and a rotor side power grid;
the stator side power grid is connected with one end of an alternating current output end of the stator side series three-phase transformer;
the other end of the alternating current output end of the three-phase series transformer at the stator side is connected with a stator winding of the variable frequency transformer;
the alternating current input end of the stator side three-phase series transformer is connected with the alternating current end of the stator side three-phase series transformer;
the rotor side power grid is connected with one end of an alternating current output end of the rotor side series three-phase transformer;
the other end of the alternating current output end of the three-phase series transformer at the rotor side is connected with a rotor winding of the variable frequency transformer;
the alternating current input end of the rotor side three-phase series transformer is connected with the alternating current end of the rotor side three-phase series converter;
the direct current motor of the variable frequency transformer is connected with the direct current output end of the H-bridge converter;
the direct-current input end of the H-bridge converter is connected with the direct-current end of the stator-side series three-phase converter and the direct-current end of the rotor-side series three-phase converter;
and the control signal input ends of the stator side series three-phase converter and the rotor side series three-phase converter are connected with the control circuit.
Preferably, the circuit further comprises a dc capacitor, and the dc capacitor is connected to the dc input terminal of the H-bridge converter.
Compared with the prior art, the technical scheme of the invention has the beneficial effects that:
compared with the technical scheme of adopting a parallel three-phase converter and a series three-phase converter, the invention has the advantages that no equipment is added, the function of the parallel three-phase converter is integrated into the stator side series three-phase converter, the voltage of the stator and the rotor is controllable, and the fluctuation of electromagnetic torque, active power and reactive power is thoroughly inhibited.
Compared with the technical scheme of adopting two parallel three-phase converters and two series three-phase converters, the invention can realize the fault ride-through control of the variable frequency transformer without the parallel three-phase converters, reduces the number of the three-phase converters of the fault ride-through circuit from 4 to 2, and greatly reduces the system cost.
Drawings
Fig. 1 is a schematic diagram of a variable frequency transformer fault ride-through circuit employing a parallel three-phase converter and a series three-phase converter.
Fig. 2 is a schematic diagram of a variable frequency transformer fault ride-through circuit employing two parallel three-phase converters and two series three-phase converters.
Fig. 3 is a flowchart illustrating a control method of a stator-side series three-phase inverter.
Fig. 4 is a flowchart illustrating a control method of the rotor-side series three-phase converter.
Fig. 5 is a schematic structural diagram of a fault ride-through circuit of the variable frequency transformer according to embodiment 2.
In the figure: the system comprises a 1-stator side power grid, a 2-rotor side power grid, a 3-series three-phase transformer, a 4-series three-phase converter, a 5-parallel three-phase converter, a 6-H bridge converter, a 7-direct current capacitor, an 8-filter inductor, a 9-variable frequency transformer, a 31-stator side series three-phase transformer, a 32-rotor side series three-phase transformer, a 41-stator side series three-phase converter and a 42-rotor side series three-phase converter.
Detailed Description
The drawings are for illustrative purposes only and are not to be construed as limiting the patent;
for the purpose of better illustrating the embodiments, certain features of the drawings may be omitted, enlarged or reduced, and do not represent the size of an actual product;
it will be understood by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted.
The technical solution of the present invention is further described below with reference to the accompanying drawings and examples.
Example 1:
the purpose of the application is to provide a variable frequency transformer fault ride-through circuit without a parallel three-phase converter, and provide a fault ride-through control method, so that the purpose of solving the problem of unbalance on the left side by using a series three-phase converter on the left side and solving the problem of unbalance on the right side by using a series three-phase converter on the right side is achieved, and the voltage stability of a direct current bus and the control capability of reactive power can be maintained without the need of the parallel three-phase converter.
The specific idea is as follows: by controlling the output voltage of the three-phase converter connected in series at the stator side, the following effects are achieved: (1) maintaining the voltage of the direct current bus stable; (2) maintaining control capability over reactive power; (3) the negative sequence voltage of the stator is suppressed.
The negative sequence voltage of the rotor is suppressed by controlling the output voltage of the rotor-side series three-phase converter.
The method comprises the steps of controlling a stator side series three-phase converter and controlling a rotor side series three-phase converter;
the control method of the stator side series three-phase converter comprises the following specific steps:
referring to fig. 3, fig. 3 is a flowchart illustrating a control method of a stator-side series three-phase converter.
Step (1-1): stator side grid voltage u is collected by voltage sensorsgabcStator voltage usabcStator side series three-phase converter voltage uscc1abcAnd DC capacitor voltage Vdc；
Stator current i is collected by using current sensorsabcAnd stator side series three-phase converter current iscc1abc；
Step (1-2): stator voltage usabcAnd stator current isabcObtaining the stator reactive power Q through power calculation processings；
Connecting stator side in series with three-phase converter voltage uscc1abcStator side series three-phase converter current iscc1abcStator-side grid voltage usgabcAnd stator voltage usabcRespectively carrying out conversion processing from three-phase static to two-phase static coordinates to obtain a voltage vector u of a stator-side series three-phase converter under a two-phase static coordinate systemscc1αβStator side series three-phase converter current vector iscc1αβStator-side grid voltage vector usgαβAnd stator voltage vector usαβ；
Connecting stator side in series with three-phase converter voltage vector uscc1αβStator side series three-phase converter current vector iscc1αβStator-side grid voltage vector usgαβAnd stator voltage vector usαβRespectively carrying out positive and negative sequence separation treatment to obtain a positive sequence voltage vector u of the stator side series three-phase converterscc1αβ+Stator side series three-phase converter positive sequence current vector iscc1αβ+Negative sequence voltage vector u of stator side power gridsgαβ-And stator negative sequence voltage vector usαβ-。
Connecting the stator side in series with the positive sequence voltage vector u of the three-phase converterscc1αβ+And stator side grid negative sequence voltage vector usgαβ-Respectively calculating and processing phase angles to obtain positive sequence phase thetasg+And negative sequence phase thetasg-；
Connecting stator side in series with three-phase converter positive sequence current vector iscc1αβ+And stator negative sequence voltage vector usαβ-Respectively carrying out conversion treatment from two-phase static to two-phase rotating coordinates to obtain positive sequence current direct-current components of the stator-side series three-phase converter under a synchronous rotating coordinate system
Figure BDA0002448965820000081
And negative sequence voltage DC component of stator
Figure BDA0002448965820000082
Step (1-3): the voltage V of the DC capacitordcStator reactive power QsStator side series three-phase converter positive sequence current direct current component
Figure BDA0002448965820000083
And negative sequence voltage DC component of stator
Figure BDA0002448965820000084
Processing according to a preset voltage control equation to obtain a direct-current component of a positive sequence voltage reference value of the three-phase converter connected in series at the stator side
Figure BDA0002448965820000085
And a stator side series three-phase converter negative sequence voltage reference value direct current component
Figure BDA0002448965820000086
The preset voltage control equation is as follows:
Figure BDA0002448965820000087
wherein, Kp1And Ki1The proportional coefficient and the integral coefficient of the direct current capacitor voltage controller are respectively; kp2And Ki2Respectively are a proportional coefficient and an integral coefficient of the stator reactive power controller; kp3And Ki3Proportional coefficients and integral coefficients of a d-axis positive sequence current controller of the three-phase converter connected in series at the stator side are respectively; kp4And Ki4Proportional coefficients and integral coefficients of a q-axis positive sequence current controller of a stator side series three-phase converter are respectively obtained; kp5And Ki5Proportional coefficient and integral coefficient of the stator d-axis negative sequence voltage controller are respectively; kp6And Ki6Proportional and integral coefficients of the stator q-axis negative sequence voltage controller are provided.
s represents the laplace operator and is,
Figure BDA0002448965820000088
is composed of
Figure BDA0002448965820000089
The d-axis component of (a) is,
Figure BDA00024489658200000810
is composed of
Figure BDA00024489658200000811
The q-axis component of (a) is,
Figure BDA00024489658200000812
is composed of
Figure BDA00024489658200000813
The d-axis component of (a) is,
Figure BDA00024489658200000814
is composed of
Figure BDA00024489658200000815
The q-axis component of (a) is,
Figure BDA00024489658200000816
is composed of
Figure BDA00024489658200000817
The d-axis component of (a) is,
Figure BDA00024489658200000818
is composed of
Figure BDA00024489658200000819
The q-axis component of (a) is,
Figure BDA00024489658200000820
is composed of
Figure BDA00024489658200000821
The d-axis component of (a) is,
Figure BDA00024489658200000822
is composed of
Figure BDA00024489658200000823
The q-axis component of (a) is,
Figure BDA00024489658200000824
represents a reference value of the dc bus voltage,
Figure BDA00024489658200000825
determined by the effective value of the ac side line voltage,
Figure BDA0002448965820000091
the minimum value of the voltage is required to be larger than the effective value of the alternating-current side line voltage, otherwise, the system is unstable;
Figure BDA0002448965820000092
representing a reactive power reference value; setting the reactive power required by the variable frequency transformer to QmWhen setting up
Figure BDA0002448965820000093
The variable frequency transformer will absorb a magnitude of Q from the stator side and the rotor side, respectivelymA reactive power of/2. If the stator side and the rotor side are respectively connected in parallel with a reactive compensation capacity of QmAnd 2, the variable frequency transformer does not need to absorb reactive power from the power grids on two sides.
Figure BDA0002448965820000094
And
Figure BDA0002448965820000095
and manually setting according to actual conditions.
Step (1-4): connecting the positive sequence voltage reference value DC component of the three-phase converter in series on the stator side
Figure BDA0002448965820000096
And a stator side series three-phase converter negative sequence voltage reference value direct current component
Figure BDA0002448965820000097
Respectively carrying out conversion treatment from two-phase rotation to two-phase static coordinates to obtain a positive sequence voltage reference value of a stator side series three-phase converter under a two-phase static coordinate system
Figure BDA0002448965820000098
Negative sequence voltage reference value of three-phase converter connected in series with stator side
Figure BDA0002448965820000099
Connecting the stator side in series with the positive sequence voltage reference value of the three-phase converter
Figure BDA00024489658200000910
Negative sequence voltage reference value of three-phase converter connected in series with stator side
Figure BDA00024489658200000911
Adding to obtain the voltage reference value of the stator side series three-phase converter under the two-phase static coordinate system
Figure BDA00024489658200000912
Step (1-5): connecting the stator side in series with the voltage reference value of the three-phase converter
Figure BDA00024489658200000913
Obtaining a control signal S of a stator side series three-phase converter switch through space vector modulation1、S2、S3。
The control method of the rotor side series three-phase converter comprises the following steps:
as shown in fig. 4, fig. 4 is a flowchart illustrating a control method of the rotor-side series three-phase converter.
Step (2-1): method for collecting rotor side grid voltage u by using voltage sensorrgabcAnd rotor voltage urabc；
Step (2-2): the rotor-side grid voltage urgabcAnd rotor voltage urabcRespectively carrying out conversion processing from three-phase static coordinates to two-phase static coordinates to obtain a rotor side power grid voltage vector u under a two-phase static coordinate systemrgαβAnd rotor voltage vector urαβ；
The rotor side grid voltage vector urgαβAnd rotor voltage vector urαβRespectively carrying out positive and negative sequence separation treatment,obtaining a positive sequence voltage vector u of a rotor side power gridrgαβ+Negative sequence voltage vector u of rotor side power gridrgαβ-Positive sequence voltage vector u of rotorrαβ+And rotor negative sequence voltage vector urαβ-。
The positive sequence voltage vector u of the rotor side power gridrgαβ+And rotor side grid negative sequence voltage vector urgαβ-Respectively calculating and processing phase angles to obtain positive sequence phase thetarg+And negative sequence phase thetarg-；
The positive sequence voltage vector u of the rotor side power gridrgαβ+Positive sequence voltage vector u of rotorrαβ+And rotor negative sequence voltage vector urαβ-Respectively carrying out conversion treatment from two-phase static to two-phase rotating coordinates to obtain the positive sequence voltage direct-current component of the rotor side power grid under the synchronous rotating coordinate system
Figure BDA0002448965820000101
Direct component of rotor positive sequence voltage
Figure BDA0002448965820000102
And negative sequence voltage DC component of rotor
Figure BDA0002448965820000103
Step (2-3): the positive sequence voltage direct current component of the rotor side power grid
Figure BDA0002448965820000104
Direct component of rotor positive sequence voltage
Figure BDA0002448965820000105
And negative sequence voltage DC component of rotor
Figure BDA0002448965820000106
Processing according to a preset voltage control equation to obtain a direct-current component of a positive sequence voltage reference value of the rotor-side series three-phase converter
Figure BDA0002448965820000107
Three-phase transformation connected in series with rotor sideNegative sequence voltage reference value DC component of converter
Figure BDA0002448965820000108
The preset voltage control equation is as follows:
Figure BDA0002448965820000109
wherein, Kp7And Ki7Proportional coefficients and integral coefficients of the rotor d-axis positive sequence voltage controller are respectively; kp8And Ki8Proportional coefficients and integral coefficients of a rotor q-axis positive sequence voltage controller are respectively; kp9And Ki9Proportional coefficient and integral coefficient of the rotor d-axis negative sequence voltage controller are respectively; kp10And Ki10Proportional coefficients and integral coefficients of a rotor q-axis negative sequence voltage controller are respectively provided;
s represents the laplace operator and is,
Figure BDA00024489658200001010
is composed of
Figure BDA00024489658200001011
The d-axis component of (a) is,
Figure BDA00024489658200001012
to represent
Figure BDA00024489658200001013
The q-axis component of (a) is,
Figure BDA00024489658200001014
to represent
Figure BDA00024489658200001015
The d-axis component of (a) is,
Figure BDA00024489658200001016
to represent
Figure BDA00024489658200001017
The q-axis component of (a) is,
Figure BDA00024489658200001018
to represent
Figure BDA00024489658200001019
The d-axis component of (a) is,
Figure BDA00024489658200001020
to represent
Figure BDA00024489658200001021
The q-axis component of (a) is,
Figure BDA00024489658200001022
to represent
Figure BDA00024489658200001023
The d-axis component of (a) is,
Figure BDA00024489658200001024
to represent
Figure BDA00024489658200001025
The q-axis component of (a) is,
Figure BDA00024489658200001026
to represent
Figure BDA00024489658200001027
The d-axis component of (a) is,
Figure BDA00024489658200001028
to represent
Figure BDA00024489658200001029
Q-axis component of (a).
Step (2-4): connecting the rotor side in series with the positive sequence voltage reference value direct current component of the three-phase converter
Figure BDA00024489658200001030
And rotor side stringNegative sequence voltage reference value direct current component of three-phase converter
Figure BDA00024489658200001031
Respectively carrying out conversion treatment from two-phase rotation to two-phase static coordinates to obtain a positive sequence voltage reference value of a rotor side series three-phase converter under a two-phase static coordinate system
Figure BDA00024489658200001032
Negative sequence voltage reference value of three-phase converter connected in series with rotor side
Figure BDA00024489658200001033
Connecting the rotor side in series with the positive sequence voltage reference value of the three-phase converter
Figure BDA00024489658200001034
Negative sequence voltage reference value of three-phase converter connected in series with rotor side
Figure BDA00024489658200001035
Adding to obtain the voltage reference value of the rotor side series three-phase converter under the two-phase static coordinate system
Figure BDA00024489658200001036
Step (2-5): connecting the rotor side in series with the voltage reference value of the three-phase converter
Figure BDA00024489658200001037
Obtaining a control signal S of a three-phase converter switch connected in series at the rotor side through space vector modulation4、S5、S6。
Example 2:
the present embodiment provides a fault ride-through circuit for a variable frequency transformer, as shown in fig. 5, including: a stator-side power grid 1, a stator-side series three-phase transformer 31, a stator-side series three-phase converter 41, a control circuit, an H-bridge converter 6, a rotor-side series three-phase converter 42, a rotor-side series three-phase transformer 32, and a rotor-side power grid 2;
the stator-side power grid 1 is connected with one end of an alternating current output end of a stator-side series three-phase transformer 31;
the other end of the alternating current output end of the stator-side three-phase series transformer 31 is connected with a stator winding of the variable frequency transformer 9;
the ac input terminal of the stator-side three-phase series transformer 31 is connected to the ac terminal of the stator-side three-phase series converter 41;
the rotor side power grid 2 is connected with one end of an alternating current output end of a rotor side series three-phase transformer 32;
the other end of the alternating current output end of the rotor-side three-phase series transformer 32 is connected with a rotor winding of the variable frequency transformer 9;
the ac input terminal of the rotor-side three-phase series transformer 32 is connected to the ac terminal of the rotor-side series three-phase converter 42;
the direct current motor of the variable frequency transformer 9 is connected with the direct current output end of the H-bridge converter 6;
the dc input terminal of the H-bridge converter 6 is connected to the dc terminals of the stator-side series three-phase converter 41 and the rotor-side series three-phase converter 42;
control signal input terminals of the stator-side three-phase converter 41 and the rotor-side three-phase converter 42 are connected to a control circuit.
The circuit further comprises a direct current capacitor 7, and the direct current capacitor 7 is connected with the direct current input end of the H-bridge converter 6.
The terms describing positional relationships in the drawings are for illustrative purposes only and are not to be construed as limiting the patent;
it should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Claims (6)

1. A variable frequency transformer fault ride-through control method for controlling a variable frequency transformer fault ride-through circuit, the circuit comprising: the system comprises a stator side power grid, a stator side series three-phase transformer, a stator side series three-phase converter, a control circuit, an H-bridge converter, a rotor side series three-phase transformer and a rotor side power grid;
the stator side power grid is connected with one end of an alternating current output end of the stator side series three-phase transformer;
the other end of the alternating current output end of the three-phase series transformer at the stator side is connected with a stator winding of the variable frequency transformer;
the alternating current input end of the stator side three-phase series transformer is connected with the alternating current end of the stator side three-phase series transformer;
the rotor side power grid is connected with one end of an alternating current output end of the rotor side series three-phase transformer;
the other end of the alternating current output end of the three-phase series transformer at the rotor side is connected with a rotor winding of the variable frequency transformer;
the alternating current input end of the rotor side three-phase series transformer is connected with the alternating current end of the rotor side three-phase series converter;
the direct current motor of the variable frequency transformer is connected with the direct current output end of the H-bridge converter;
the direct-current input end of the H-bridge converter is connected with the direct-current end of the stator-side series three-phase converter and the direct-current end of the rotor-side series three-phase converter;
the control signal input ends of the stator side series three-phase converter and the rotor side series three-phase converter are connected with the control circuit; the circuit also comprises a direct current capacitor, and the direct current capacitor is connected with the direct current input end of the H-bridge converter; the method comprises the steps of controlling a stator side series three-phase converter and controlling a rotor side series three-phase converter;
the control method of the stator side series three-phase converter comprises the following steps:
step (1-1): collecting stator side grid electricityPress usgabcStator voltage usabcStator side series three-phase converter voltage uscc1abcDC capacitor voltage VdcStator current isabcAnd stator side series three-phase converter current iscc1abc；
Step (1-2): the stator-side grid voltage usgabcStator voltage usabcStator side series three-phase converter voltage uscc1abcStator current isabcAnd stator side series three-phase converter current iscc1abcProcessing to obtain stator reactive power QsStator side series three-phase converter positive sequence current direct current component
Figure FDA0003065274470000011
And negative sequence voltage DC component of stator
Figure FDA0003065274470000021
Step (1-3): the voltage V of the DC capacitordcStator reactive power QsStator side series three-phase converter positive sequence current direct current component
Figure FDA0003065274470000022
And negative sequence voltage DC component of stator
Figure FDA0003065274470000023
Processing according to a preset voltage control equation to obtain a direct-current component of a positive sequence voltage reference value of the three-phase converter connected in series at the stator side
Figure FDA0003065274470000024
And a stator side series three-phase converter negative sequence voltage reference value direct current component
Figure FDA0003065274470000025
The preset voltage control equation in the step (1-3) is as follows:
Figure FDA0003065274470000026
wherein, Kp1And Ki1The proportional coefficient and the integral coefficient of the direct current capacitor voltage controller are respectively; kp2And Ki2Respectively are a proportional coefficient and an integral coefficient of the stator reactive power controller; kp3And Ki3Proportional coefficients and integral coefficients of a d-axis positive sequence current controller of the three-phase converter connected in series at the stator side are respectively; kp4And Ki4Proportional coefficients and integral coefficients of a q-axis positive sequence current controller of a stator side series three-phase converter are respectively obtained; kp5And Ki5Proportional coefficient and integral coefficient of the stator d-axis negative sequence voltage controller are respectively; kp6And Ki6Proportional coefficients and integral coefficients of the stator q-axis negative sequence voltage controller are respectively;
s represents the laplace operator and is,
Figure FDA0003065274470000027
is composed of
Figure FDA0003065274470000028
The d-axis component of (a) is,
Figure FDA0003065274470000029
is composed of
Figure FDA00030652744700000210
The q-axis component of (a) is,
Figure FDA00030652744700000211
is composed of
Figure FDA00030652744700000212
The d-axis component of (a) is,
Figure FDA00030652744700000213
is composed of
Figure FDA00030652744700000214
The q-axis component of (a) is,
Figure FDA00030652744700000215
is composed of
Figure FDA00030652744700000216
The d-axis component of (a) is,
Figure FDA00030652744700000217
is composed of
Figure FDA00030652744700000218
The q-axis component of (a) is,
Figure FDA00030652744700000219
is composed of
Figure FDA00030652744700000220
The d-axis component of (a) is,
Figure FDA00030652744700000221
is composed of
Figure FDA00030652744700000222
The q-axis component of (a) is,
Figure FDA00030652744700000223
represents a reference value of the dc bus voltage,
Figure FDA00030652744700000224
representing a reactive power reference value;
step (1-4): according to the positive sequence voltage reference value direct current component of the stator side series three-phase converter
Figure FDA00030652744700000225
And a stator side series three-phase converter negative sequence voltage reference value direct current component
Figure FDA00030652744700000226
Obtaining a voltage reference value of a stator side series three-phase converter under a two-phase static coordinate system
Figure FDA00030652744700000227
Step (1-5): connecting the stator side in series with the voltage reference value of the three-phase converter
Figure FDA00030652744700000228
Obtaining a control signal S of a stator side series three-phase converter switch through space vector modulation1、S2、S3；
The control method of the rotor side series three-phase converter comprises the following steps:
step (2-1): collecting rotor side grid voltage urgabcAnd rotor voltage urabc；
Step (2-2): according to the rotor-side grid voltage urgabcAnd rotor voltage urabcObtaining the positive sequence voltage DC component of the rotor side power grid
Figure FDA0003065274470000031
Direct component of rotor positive sequence voltage
Figure FDA0003065274470000032
And negative sequence voltage DC component of rotor
Figure FDA0003065274470000033
Step (2-3): the positive sequence voltage direct current component of the rotor side power grid
Figure FDA0003065274470000034
Direct component of rotor positive sequence voltage
Figure FDA0003065274470000035
And a rotorNegative sequence voltage DC component
Figure FDA0003065274470000036
Processing according to a preset voltage control equation to obtain a direct-current component of a positive sequence voltage reference value of the rotor-side series three-phase converter
Figure FDA0003065274470000037
And rotor side series three-phase converter negative sequence voltage reference value direct current component
Figure FDA0003065274470000038
Step (2-4): according to the positive sequence voltage reference value direct current component of the rotor side series three-phase converter
Figure FDA0003065274470000039
And rotor side series three-phase converter negative sequence voltage reference value direct current component
Figure FDA00030652744700000310
Obtaining a voltage reference value of a rotor-side series three-phase converter under a two-phase static coordinate system
Figure FDA00030652744700000311
Step (2-5): connecting the rotor side in series with the voltage reference value of the three-phase converter
Figure FDA00030652744700000312
Obtaining a control signal S of a three-phase converter switch connected in series at the rotor side through space vector modulation4、S5、S6。
2. The method and circuit for controlling fault ride-through of a variable frequency transformer according to claim 1, wherein the step (1-2) is specifically:
stator voltage usabcAnd stator current isabcAfter the power calculation processing, the power calculation processing is carried out,obtaining the reactive power Q of the stators(ii) a Connecting stator side in series with three-phase converter voltage uscc1abcStator side series three-phase converter current iscc1abcStator-side grid voltage usgabcAnd stator voltage usabcRespectively carrying out conversion processing from three-phase static to two-phase static coordinates to obtain a voltage vector u of a stator-side series three-phase converter under a two-phase static coordinate systemscc1αβStator side series three-phase converter current vector iscc1αβStator-side grid voltage vector usgαβAnd stator voltage vector usαβ；
Connecting stator side in series with three-phase converter voltage vector uscc1αβStator side series three-phase converter current vector iscc1αβStator-side grid voltage vector usgαβAnd stator voltage vector usαβRespectively carrying out positive and negative sequence separation treatment to obtain a positive sequence voltage vector u of the stator side series three-phase converterscc1αβ+Stator side series three-phase converter positive sequence current vector iscc1αβ+Negative sequence voltage vector u of stator side power gridsgαβ-And stator negative sequence voltage vector usαβ-；
Connecting the stator side in series with the positive sequence voltage vector u of the three-phase converterscc1αβ+And stator side grid negative sequence voltage vector usgαβRespectively obtaining the positive sequence phase theta through phase angle calculation processingsg+And negative sequence phase thetasg-；
Connecting stator side in series with three-phase converter positive sequence current vector iscc1αβ+And stator negative sequence voltage vector usαβ-Respectively carrying out conversion treatment from two-phase static to two-phase rotating coordinates to obtain positive sequence current direct-current components of the stator-side series three-phase converter under a synchronous rotating coordinate system
Figure FDA00030652744700000313
And negative sequence voltage DC component of stator
Figure FDA00030652744700000314
3. The method and circuit for controlling fault ride-through of a variable frequency transformer according to claim 2, wherein the steps (1-4) are specifically as follows:
connecting the positive sequence voltage reference value DC component of the three-phase converter in series on the stator side
Figure FDA0003065274470000041
And a stator side series three-phase converter negative sequence voltage reference value direct current component
Figure FDA0003065274470000042
Respectively carrying out conversion treatment from two-phase rotation to two-phase static coordinates to obtain a positive sequence voltage reference value of a stator side series three-phase converter under a two-phase static coordinate system
Figure FDA0003065274470000043
Negative sequence voltage reference value of three-phase converter connected in series with stator side
Figure FDA0003065274470000044
Connecting the stator side in series with the positive sequence voltage reference value of the three-phase converter
Figure FDA0003065274470000045
Negative sequence voltage reference value of three-phase converter connected in series with stator side
Figure FDA0003065274470000046
Adding to obtain the voltage reference value of the stator side series three-phase converter under the two-phase static coordinate system
Figure FDA0003065274470000047
4. The method and circuit for controlling fault ride-through of a variable frequency transformer according to claim 1 or 3, wherein the step (2-2) is specifically:
the rotor-side grid voltage urgabcAnd rotor voltage urabcRespectively carrying out conversion processing from three-phase static coordinates to two-phase static coordinates to obtain a rotor side power grid voltage vector u under a two-phase static coordinate systemrgαβAnd rotor voltage vector urαβ；
The rotor side grid voltage vector urgαβAnd rotor voltage vector urαβRespectively carrying out positive and negative sequence separation treatment to obtain a rotor side power grid positive sequence voltage vector urgαβ+Negative sequence voltage vector u of rotor side power gridrgαβ-, rotor positive sequence voltage vector urαβ+And rotor negative sequence voltage vector urαβ-；
The positive sequence voltage vector u of the rotor side power gridrgαβ+And rotor side grid negative sequence voltage vector urgαβ-Respectively calculating and processing phase angles to obtain positive sequence phase thetarg+And negative sequence phase thetarg-；
The positive sequence voltage vector u of the rotor side power gridrgαβ+Positive sequence voltage vector u of rotorrαβ+And rotor negative sequence voltage vector urαβ-Respectively carrying out conversion treatment from two-phase static to two-phase rotating coordinates to obtain the positive sequence voltage direct-current component of the rotor side power grid under the synchronous rotating coordinate system
Figure FDA0003065274470000048
Direct component of rotor positive sequence voltage
Figure FDA0003065274470000049
And negative sequence voltage DC component of rotor
Figure FDA00030652744700000410
5. The method and circuit for controlling fault ride-through of a variable frequency transformer according to claim 4, wherein the preset voltage control equation in step (2-3) is as follows:
Figure FDA00030652744700000411
wherein, Kp7And Ki7Proportional coefficients and integral coefficients of the rotor d-axis positive sequence voltage controller are respectively; kp8And Ki8Proportional coefficients and integral coefficients of a rotor q-axis positive sequence voltage controller are respectively; kp9And Ki9Proportional coefficient and integral coefficient of the rotor d-axis negative sequence voltage controller are respectively; kp10And Ki10Proportional coefficients and integral coefficients of a rotor q-axis negative sequence voltage controller are respectively provided;
s represents the laplace operator and is,
Figure FDA0003065274470000051
is composed of
Figure FDA0003065274470000052
The d-axis component of (a) is,
Figure FDA0003065274470000053
to represent
Figure FDA0003065274470000054
The q-axis component of (a) is,
Figure FDA0003065274470000055
to represent
Figure FDA0003065274470000056
The d-axis component of (a) is,
Figure FDA0003065274470000057
to represent
Figure FDA0003065274470000058
The q-axis component of (a) is,
Figure FDA0003065274470000059
to represent
Figure FDA00030652744700000510
The d-axis component of (a) is,
Figure FDA00030652744700000511
to represent
Figure FDA00030652744700000512
The q-axis component of (a) is,
Figure FDA00030652744700000513
to represent
Figure FDA00030652744700000514
The d-axis component of (a) is,
Figure FDA00030652744700000515
to represent
Figure FDA00030652744700000516
The q-axis component of (a) is,
Figure FDA00030652744700000517
to represent
Figure FDA00030652744700000518
The d-axis component of (a) is,
Figure FDA00030652744700000519
to represent
Figure FDA00030652744700000520
Q-axis component of (a).
6. The method and circuit for controlling fault ride-through of a variable frequency transformer according to claim 5, wherein the steps (2-4) are specifically as follows:
connecting the rotor side in series with the positive sequence voltage reference value direct current component of the three-phase converter
Figure FDA00030652744700000521
And rotor side series three-phase converter negative sequence voltage reference value direct current component
Figure FDA00030652744700000522
Respectively carrying out conversion treatment from two-phase rotation to two-phase static coordinates to obtain a positive sequence voltage reference value of a rotor side series three-phase converter under a two-phase static coordinate system
Figure FDA00030652744700000523
Negative sequence voltage reference value of three-phase converter connected in series with rotor side
Figure FDA00030652744700000524
Connecting the rotor side in series with the positive sequence voltage reference value of the three-phase converter
Figure FDA00030652744700000525
Negative sequence voltage reference value of three-phase converter connected in series with rotor side
Figure FDA00030652744700000526
Adding to obtain the voltage reference value of the rotor side series three-phase converter under the two-phase static coordinate system
Figure FDA00030652744700000527
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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107919669A (en) * 2017-12-18 2018-04-17 广东工业大学 A kind of variable frequency transformer fault passes through the control method and interlock circuit of circuit
CN108923443A (en) * 2018-06-25 2018-11-30 上海电力学院 A kind of Lyapunov control method for coordinating of the DFIG using PGSC and SGSC
CN109066735A (en) * 2018-08-29 2018-12-21 国网内蒙古东部电力有限公司电力科学研究院 Dual feedback wind power generation system and its control method under a kind of unbalanced electric grid voltage
CN109256798A (en) * 2018-07-23 2019-01-22 华中科技大学 DFIG system passes through operation method under a kind of voltage symmetry failure
CN109995049A (en) * 2019-04-24 2019-07-09 广东工业大学 A kind of the fault traversing control method and relevant apparatus of variable frequency transformer

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107919669A (en) * 2017-12-18 2018-04-17 广东工业大学 A kind of variable frequency transformer fault passes through the control method and interlock circuit of circuit
CN108923443A (en) * 2018-06-25 2018-11-30 上海电力学院 A kind of Lyapunov control method for coordinating of the DFIG using PGSC and SGSC
CN109256798A (en) * 2018-07-23 2019-01-22 华中科技大学 DFIG system passes through operation method under a kind of voltage symmetry failure
CN109066735A (en) * 2018-08-29 2018-12-21 国网内蒙古东部电力有限公司电力科学研究院 Dual feedback wind power generation system and its control method under a kind of unbalanced electric grid voltage
CN109995049A (en) * 2019-04-24 2019-07-09 广东工业大学 A kind of the fault traversing control method and relevant apparatus of variable frequency transformer

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
Immunizing Variable Frequency Transformer From Dual-Side Asymmetrical Grid Faults via a Single-Converter-Based Novel Control Strategy;Si-Zhe Chen;《IEEE Transactions on Power Delivery》;20190911;全文 *
可变频率变压器的电网故障穿越控制技术研究;卢嘉豪;《中国优秀硕士学位论文全文数据库工程科技II辑》;20200215;第3-4章 *

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