Vector control system and method for high-voltage frequency converter

Abstract

The invention particularly relates to a high-voltage frequency converter vector control system, and the system comprises a voltage and current measurement module which is used for collecting a voltage value and a current value of an input motor; the first coordinate conversion module is used for converting the voltage value and the current value into a D-Q coordinate from a three-coordinate system; the flux linkage observation and rotation speed estimation module is used for calculating a motor rotor flux linkage estimation value and a motor rotor rotation speed estimation value; the current PI regulator is used for calculating a current given value under the D-Q coordinate system; the voltage PI regulator is used for calculating a voltage given value under the D-Q coordinate system; the second coordinate conversion module is used for converting a voltage given value under the D-Q coordinate system into a voltage given value under a three-coordinate system; and outputting a PWM modulation wave to a PWM inversion loop of the high-voltage frequency converter according to the voltage given value under the three-coordinate system. The invention further relates to a high-voltage frequency converter vector control method. The output rotating speed overshoot of the high-voltage frequency converter is effectively inhibited.

Description

Technical Field

[0001] The present invention relates to the technical field of high-voltage inverter vector control, and in particular to a high-voltage inverter vector control system and method. Background Art

[0002] Asynchronous motors have many inherent advantages, such as simple structure, small size, high speed, durability, large capacity and suitability for harsh environments. Therefore, asynchronous motor speed control technology is gaining more and more attention.

[0003] The emergence of many advanced control strategies has promoted the rapid development of asynchronous motor speed control systems. Among the many advanced control strategies, high-voltage inverter vector control is widely used. High-voltage inverter vector control has greatly improved the dynamic performance of AC transmission systems and has become an important research direction for asynchronous motor speed control systems. Due to the large number of inertia links in high-voltage inverter vector control, there is a problem of speed overshoot and callback after the motor reaches the predetermined speed, which limits the application of high-voltage inverter vector control in occasions where the speed control accuracy requirements are relatively high. Summary of the invention

[0004] The object of the present invention is to provide a high-voltage inverter vector control system and method, which can effectively suppress the overshoot of the output speed of the high-voltage inverter and realize the precise control of the output speed of the high-voltage inverter.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] A high voltage inverter vector control system, comprising:

[0007] The voltage and current measurement module is used to collect the voltage value and current value output from the PWM inverter circuit of the high-voltage inverter to the load motor of the high-voltage inverter, and obtain the voltage value in the three-coordinate system and the current value in the three-coordinate system;

[0008] A first coordinate conversion module, used for converting a voltage value in a three-coordinate system and a current value in a three-coordinate system into a voltage value in a DQ coordinate system and a current value in a DQ coordinate system;

[0009] The flux observation and speed estimation module is used to calculate the motor rotor flux estimation value and the motor rotor speed estimation value according to the voltage value in the DQ coordinate system and the current value in the DQ coordinate system;

[0010] The current PI regulator is used to compare the estimated value of the motor rotor flux with the given value of the motor rotor flux and the estimated value of the motor rotor speed with the given value of the motor rotor speed, and calculate and obtain the current given value in the DQ coordinate system;

[0011] The voltage PI regulator is used to compare the current given value in the DQ coordinate system with the current value in the DQ coordinate system, and calculate the voltage given value in the DQ coordinate system;

[0012] The second coordinate conversion module is used to convert the voltage given value in the DQ coordinate system into the voltage given value in the three-coordinate system; output the PWM modulation wave to the PWM inverter circuit of the high-voltage inverter according to the voltage given value in the three-coordinate system.

[0013] As one of the feasible ways, the voltage value in the three-coordinate system includes the three-phase voltage; the current value in the three-coordinate system includes the three-phase current value; the voltage value in the DQ coordinate system includes the D-axis voltage value and the Q-axis voltage value; the current value in the DQ coordinate system includes the D-axis current value and the Q-axis current value; the voltage given value in the three-coordinate system includes the three-phase voltage given value.

[0014] As one of the achievable methods, the current given value in the DQ coordinate system includes a D-axis current given value and a Q-axis current given value;

[0015] Current PI regulator, including:

[0016] The flux PI regulator sets the motor rotor flux given value, which is used to compare the motor rotor flux given value with the motor rotor flux estimated value, and calculate the D-axis current given value;

[0017] The speed loop PI regulator is used to compare the motor rotor speed set value with the motor rotor speed estimate value, and calculate the Q-axis current set value.

[0018] As one of the possible implementation methods, the high voltage inverter vector control system also includes:

[0019] A given speed adjustment module is provided with a motor rotor given speed adjustment curve, which is used to output a motor rotor speed given value to the two-selection module;

[0020] A two-choice module is used to output the motor rotor speed given value to the given speed limit module when the motor rotor speed estimate value is less than the motor rotor overshoot suppression speed set value; and output the motor rotor speed given value to the speed loop PI regulator when the motor rotor speed estimate value is greater than or equal to the motor rotor overshoot suppression speed set value;

[0021] The given speed limit module sets the motor rotor given speed limit curve, which is used to maintain the motor rotor speed given value at the limit value for a certain period of time after the motor rotor speed given value reaches the limit value. During this period, the motor rotor speed limit value is output as the motor rotor speed given value to the speed loop PI regulator; when the motor rotor speed given value is lower than the limit value, the motor rotor speed given value is output to the speed loop PI regulator;

[0022] The comparison module sets the motor rotor overshoot suppression speed setting value and is used to compare the motor rotor speed estimation value with the motor rotor overshoot suppression speed setting value.

[0023] As one of the achievable ways, the motor rotor given speed adjustment curve includes the motor rotor given speed value and the corresponding time; the motor rotor given speed limiting curve includes the motor rotor given speed limiting value and the corresponding limiting time.

[0024] As one of the achievable ways, the voltage given value in the DQ coordinate system includes a D-axis voltage given value and a Q-axis voltage given value;

[0025] Voltage PI regulator, including:

[0026] The Q-axis voltage PI regulator is used to compare the Q-axis current set value and the Q-axis current value, and calculate the Q-axis voltage set value;

[0027] The D-axis voltage PI regulator is used to compare the D-axis current given value and the D-axis current value, and calculate to obtain the D-axis voltage given value.

[0028] The present invention also provides a high-voltage inverter vector control method, using the above-mentioned high-voltage inverter vector control system, comprising the following steps:

[0029] The voltage and current measurement module collects the voltage value and current value output from the PWM inverter circuit of the high-voltage inverter to the load motor of the high-voltage inverter, and obtains the voltage value in the three-coordinate system and the current value in the three-coordinate system;

[0030] The first coordinate conversion module converts the voltage value in the three-coordinate system and the current value in the three-coordinate system into the voltage value in the DQ coordinate system and the current value in the DQ coordinate system;

[0031] The flux observation and speed estimation module calculates the motor rotor flux estimation value and the motor rotor speed estimation value according to the voltage value in the DQ coordinate system and the current value in the DQ coordinate system;

[0032] The current PI regulator compares the motor rotor flux estimation value with the motor rotor flux setting value and the motor rotor speed estimation value with the motor rotor speed setting value, and calculates and obtains the current setting value in the DQ coordinate system;

[0033] The voltage PI regulator compares the current given value in the DQ coordinate system with the current value in the DQ coordinate system, and calculates and obtains the voltage given value in the DQ coordinate system;

[0034] The second coordinate conversion module converts the voltage given value in the DQ coordinate system into the voltage given value in the three-coordinate system; outputs the PWM modulation wave to the PWM inverter circuit of the high-voltage inverter according to the voltage given value in the three-coordinate system;

[0035] The PWM inverter circuit of the high-voltage inverter carries the load motor of the high-voltage inverter according to the PWM modulation wave.

[0036] Beneficial technical effects of the present invention:

[0037] The high-voltage inverter vector control system and method of the present invention, when the motor rotor speed estimate value is less than the motor rotor overshoot suppression speed setting value, the two-selection module outputs the motor rotor speed given value to the given speed limit module to execute the motor rotor speed overshoot suppression function; after the motor rotor speed given value reaches the limit value, the given speed limit module maintains the motor rotor speed given value at the limit value for a certain period of time, during which time, the motor rotor speed limit value is output as the motor rotor speed given value to the speed loop PI regulator; when the motor rotor speed given value is lower than the limit value, the given speed limit module outputs the motor rotor speed given value to the speed loop PI regulator; when the motor rotor speed estimate value is greater than or equal to the motor rotor overshoot suppression speed setting value, the motor rotor speed overshoot suppression function exits, and the two-selection module outputs the motor rotor speed given value to the speed loop PI regulator; the high-voltage inverter output speed overshoot is effectively suppressed, and the high-voltage inverter output speed is accurately controlled. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a structural schematic diagram of an embodiment of a high-voltage inverter vector control system of the present invention. DETAILED DESCRIPTION

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by technicians in the technical field of this application; the terms used in the specification of the application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, not to describe a specific order.

[0040] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0041] The technical solution of the present invention is clearly and completely described below in conjunction with the accompanying drawings and specific embodiments.

[0042] refer to Figure 1 , shows a schematic structural diagram of an embodiment of a high-voltage inverter vector control system, the high-voltage inverter vector control system comprising:

[0043] The voltage and current measurement module is used to collect the voltage value and current value output from the PWM inverter circuit of the high-voltage inverter to the load motor of the high-voltage inverter, and obtain the voltage value in the three-coordinate system and the current value in the three-coordinate system;

[0044] A first coordinate conversion module, used for converting a voltage value in a three-coordinate system and a current value in a three-coordinate system into a voltage value in a DQ coordinate system and a current value in a DQ coordinate system;

[0045] The flux observation and speed estimation module is used to calculate the estimated value of the motor rotor flux ψ according to the voltage value in the DQ coordinate system and the current value in the DQ coordinate system. r and the estimated value of the motor rotor speed ω;

[0046] Current PI regulator, used to compare the estimated value of the motor rotor flux ψ r and the motor rotor flux given value ψ r * As well as the estimated value ω of the motor rotor speed and the given value ω of the motor rotor speed * , calculate and obtain the current given value in the DQ coordinate system;

[0047] The voltage PI regulator is used to compare the current given value in the DQ coordinate system with the current value in the DQ coordinate system, and calculate the voltage given value in the DQ coordinate system;

[0048] The second coordinate conversion module is used to convert the voltage given value in the DQ coordinate system into the voltage given value in the three-coordinate system; output the PWM modulation wave to the PWM inverter circuit of the high-voltage inverter according to the voltage given value in the three-coordinate system.

[0049] In this embodiment, as one of the achievable methods, the voltage value in the three-coordinate system includes the three-phase voltage value u A 、u Band u C ; The current value in the three-coordinate system includes the three-phase current value i A 、i B and i C ; The voltage value in the DQ coordinate system includes the D-axis voltage value u d and Q-axis voltage value u q ; The current value in the DQ coordinate system includes the D-axis current value i d and Q-axis current value i q ; The voltage given value in the three-coordinate system includes the three-phase voltage given value u A * 、u B * and u C * .

[0050] In this embodiment, as one of the achievable methods, the current given value in the DQ coordinate system includes the D-axis current given value i q * and Q axis current given value i q * ;

[0051] Current PI regulator, including:

[0052] Flux PI regulator, set the motor rotor flux setpoint ψ r * , used to compare the motor rotor flux given value ψ r * and the estimated value of the motor rotor flux ψ r , calculate and obtain the D-axis current given value i d * ;

[0053] Speed ​​loop PI regulator, used to compare the motor rotor speed given value ω * The Q-axis current given value i is calculated by the motor rotor speed estimate ω q * .

[0054] In this embodiment, as one of the achievable methods, the high-voltage inverter vector control system further includes:

[0055] The given speed adjustment module is provided with a motor rotor given speed adjustment curve, which is used to output the motor rotor speed given value ω * To choose one of the two modules;

[0056] A two-choice module is used to select the motor rotor speed estimate value ω < the motor rotor overshoot suppression speed setting value ω set When the motor rotor speed is set to a given value ω *Output to the given speed limit module; when the motor rotor speed estimate ω ≥ the motor rotor overshoot suppression speed setting value ω set When the motor rotor speed is set to a given value ω * Output to the speed loop PI regulator;

[0057] Given speed limit module, set the motor rotor given speed limit curve, used to set the motor rotor speed given value ω * After reaching the limit value, the motor rotor speed is set to the given value ω * Maintain the limit value for a certain period of time, during which the motor rotor speed limit value is used as the motor rotor speed given value ω * Output to the speed loop PI regulator; when the motor rotor speed given value is lower than the limit value, the motor rotor speed given value ω * Output to the speed loop PI regulator;

[0058] Comparison module, set the motor rotor overshoot suppression speed setting value ω set , used to compare the motor rotor speed estimate ω with the motor rotor overshoot suppression speed set value ω set .

[0059] In this embodiment, as one of the achievable methods, the motor rotor given speed adjustment curve includes a motor rotor speed given value and a corresponding time; the motor rotor given speed limiting curve includes a motor rotor given speed limiting value and a corresponding limiting time.

[0060] In this embodiment, as one of the achievable methods, the voltage given value in the DQ coordinate system includes the D-axis voltage given value u d * and Q axis voltage given value u q * ;

[0061] Voltage PI regulator, including:

[0062] Q-axis voltage PI regulator, used to compare the Q-axis current given value i q * and Q-axis current value i q , calculate and get the Q axis voltage given value u q * ;

[0063] D-axis voltage PI regulator, used to compare the D-axis current given value i d * and D-axis current value i d , calculate and get the D-axis voltage given value u d * .

[0064] This embodiment also provides a high-voltage inverter vector control method, using the above-mentioned high-voltage inverter vector control system, including the following steps:

[0065] The voltage and current measurement module collects the voltage value and current value output from the PWM inverter circuit of the high-voltage inverter to the load motor of the high-voltage inverter, and obtains the voltage value in the three-coordinate system and the current value in the three-coordinate system;

[0066] The first coordinate conversion module converts the voltage value in the three-coordinate system and the current value in the three-coordinate system into the voltage value in the DQ coordinate system and the current value in the DQ coordinate system;

[0067] The flux observation and speed estimation module calculates the estimated value of the motor rotor flux ψ based on the voltage value in the DQ coordinate system and the current value in the DQ coordinate system. r and the estimated value of the motor rotor speed ω;

[0068] Current PI regulator vs. motor rotor flux estimation ψ r and the motor rotor flux given value ψ r * As well as the estimated value ω of the motor rotor speed and the given value ω of the motor rotor speed * , calculate and obtain the current given value in the DQ coordinate system;

[0069] The voltage PI regulator compares the current given value and the current value in the DQ coordinate system, and calculates the voltage given value in the DQ coordinate system;

[0070] The second coordinate conversion module converts the voltage given value in the DQ coordinate system into the voltage given value in the three-coordinate system; outputs the PWM modulation wave to the PWM inverter circuit of the high-voltage inverter according to the voltage given value in the three-coordinate system;

[0071] The PWM inverter circuit of the high-voltage inverter carries the motor according to the PWM modulation wave.

[0072] During the startup phase of the high-voltage inverter, the estimated value ω of the motor rotor speed gradually increases; when the estimated value ω of the motor rotor speed is less than the set value ω of the motor rotor overshoot suppression speed set When the two-choice module sets the motor rotor speed to a given value ω * Output to the given speed limit module to execute the motor rotor speed overshoot suppression function; the given speed limit module is set at the motor rotor speed given value ω * After reaching the limit value, the motor rotor speed is set to the given value ω * Maintain the limit value for a certain period of time, during which the motor rotor speed limit value is used as the motor rotor speed given value ω * Output to the speed loop PI regulator; given speed limit module at the motor rotor speed given value ω *When the motor rotor speed is lower than the limit value, the motor rotor speed is set to the given value ω * Output to the speed loop PI regulator; when the motor rotor speed estimate ω ≥ the motor rotor overshoot suppression speed setting value ω set When the motor rotor speed overshoot suppression function is exited, the two-choice module sets the motor rotor speed to the given value ω * The output is sent to the speed loop PI regulator; in this way, the high-voltage inverter can not only control the load motor rotor speed to reach the target value, but also reduce the motor rotor speed overshoot.

[0073] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A high voltage inverter vector control system, characterized in that: include: The voltage and current measurement module is used to collect the voltage value and current value output from the PWM inverter circuit of the high-voltage inverter to the load motor of the high-voltage inverter, and obtain the voltage value in the three-coordinate system and the current value in the three-coordinate system; A first coordinate conversion module, used for converting a voltage value in a three-coordinate system and a current value in a three-coordinate system into a voltage value in a DQ coordinate system and a current value in a DQ coordinate system; The flux observation and speed estimation module is used to calculate the motor rotor flux estimation value and the motor rotor speed estimation value according to the voltage value in the DQ coordinate system and the current value in the DQ coordinate system; The current PI regulator is used to compare the estimated value of the motor rotor flux with the given value of the motor rotor flux and the estimated value of the motor rotor speed with the given value of the motor rotor speed, and calculate and obtain the current given value in the DQ coordinate system; The voltage PI regulator is used to compare the current given value in the DQ coordinate system with the current value in the DQ coordinate system, and calculate the voltage given value in the DQ coordinate system; The second coordinate conversion module is used to convert the voltage given value in the DQ coordinate system into the voltage given value in the three-coordinate system; output the PWM modulation wave to the PWM inverter circuit of the high-voltage inverter according to the voltage given value in the three-coordinate system.

2. The high voltage inverter vector control system according to claim 1, characterized in that: The voltage value in the three-coordinate system includes the three-phase voltage; the current value in the three-coordinate system includes the three-phase current value; the voltage value in the DQ coordinate system includes the D-axis voltage value and the Q-axis voltage value; the current value in the DQ coordinate system includes the D-axis current value and the Q-axis current value; the voltage given value in the three-coordinate system includes the three-phase voltage given value.

3. The high voltage inverter vector control system according to claim 2, characterized in that: The current given value in the DQ coordinate system includes the D-axis current given value and the Q-axis current given value; Current PI regulator, including: The flux PI regulator sets the motor rotor flux given value, which is used to compare the motor rotor flux given value with the motor rotor flux estimated value, and calculate the D-axis current given value; The speed loop PI regulator is used to compare the motor rotor speed set value with the motor rotor speed estimate value, and calculate the Q-axis current set value.

4. The high voltage inverter vector control system according to claim 3, characterized in that: Also includes: A given speed adjustment module is provided with a motor rotor given speed adjustment curve, which is used to output a motor rotor speed given value to the two-selection module; A two-choice module is used to output the motor rotor speed given value to the given speed limit module when the motor rotor speed estimate value is less than the motor rotor overshoot suppression speed set value; and output the motor rotor speed given value to the speed loop PI regulator when the motor rotor speed estimate value is greater than or equal to the motor rotor overshoot suppression speed set value; The given speed limit module sets the motor rotor given speed limit curve, which is used to maintain the motor rotor speed given value at the limit value for a certain period of time after the motor rotor speed given value reaches the limit value. During this period, the motor rotor speed limit value is output as the motor rotor speed given value to the speed loop PI regulator; when the motor rotor speed given value is lower than the limit value, the motor rotor speed given value is output to the speed loop PI regulator; The comparison module sets the motor rotor overshoot suppression speed setting value and is used to compare the motor rotor speed estimation value with the motor rotor overshoot suppression speed setting value.

5. The high voltage inverter vector control system according to claim 4, characterized in that: The motor rotor given speed adjustment curve includes a motor rotor given speed value and a corresponding time; the motor rotor given speed limiting curve includes a motor rotor given speed limiting value and a corresponding limiting time.

6. The high voltage inverter vector control system according to claim 3, characterized in that: The voltage given value in the DQ coordinate system includes the D-axis voltage given value and the Q-axis voltage given value; Voltage PI regulator, including: The Q-axis voltage PI regulator is used to compare the Q-axis current given value and the Q-axis current value, and calculate the Q-axis voltage given value; The D-axis voltage PI regulator is used to compare the D-axis current given value and the D-axis current value, and calculate to obtain the D-axis voltage given value.

7. A high voltage inverter vector control method, characterized in that: The high-voltage inverter vector control system according to any one of claims 1 to 6 comprises the following steps: The voltage and current measurement module collects the voltage value and current value output from the PWM inverter circuit of the high-voltage inverter to the load motor of the high-voltage inverter, and obtains the voltage value in the three-coordinate system and the current value in the three-coordinate system; The first coordinate conversion module converts the voltage value in the three-coordinate system and the current value in the three-coordinate system into the voltage value in the DQ coordinate system and the current value in the DQ coordinate system; The flux observation and speed estimation module calculates the motor rotor flux estimation value and the motor rotor speed estimation value according to the voltage value in the DQ coordinate system and the current value in the DQ coordinate system; The current PI regulator compares the motor rotor flux estimation value with the motor rotor flux setting value and the motor rotor speed estimation value with the motor rotor speed setting value, and calculates and obtains the current setting value in the DQ coordinate system; The voltage PI regulator compares the current given value in the DQ coordinate system with the current value in the DQ coordinate system, and calculates and obtains the voltage given value in the DQ coordinate system; The second coordinate conversion module converts the voltage given value in the DQ coordinate system into the voltage given value in the three-coordinate system; outputs the PWM modulation wave to the PWM inverter circuit of the high-voltage inverter according to the voltage given value in the three-coordinate system; The PWM inverter circuit of the high-voltage inverter carries the load motor of the high-voltage inverter according to the PWM modulation wave.

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