CN102830693B - A kind of control system of low-voltage transverse test equipment of wind turbine and control method thereof - Google Patents

Abstract

The invention provides a control system and a control method for low-voltage ride-through test equipment for wind turbines. The test equipment is a voltage drop device, including a switch cabinet and a reactor; the control system includes a data acquisition system, a monitoring system, and a central processing system; the central processing The system is respectively connected with the data acquisition system and the monitoring system. When testing the present invention, the central processing system controls the combination of switch cabinets, realizes the input and withdrawal of the current-limiting reactor and the short-circuit reactor by controlling the circuit breaker, changes the state of the wind turbine into a state of voltage drop, and monitors The system monitors the operating status of the switchgear combination, the real-time temperature of the reactor, the status of the safety chain system and the status signal indication, and transmits the monitored data to the central processing system; the data acquisition system collects the test data of the wind turbine and transmits it to the central processing system, Through data analysis, it is judged whether the wind turbine has low voltage ride through capability. The invention has high degree of automation and strong stability.

Description

A control system and control method of low-voltage ride-through test equipment for wind turbines

technical field

The invention relates to the field of power systems, in particular to a control system and a control method for low-voltage ride-through test equipment for wind turbines.

Background technique

At present, my country's wind power generation has entered a large-scale development stage. In order to ensure the safe and stable operation of the power system, wind turbines that are connected to the grid must have low-voltage ride-through capabilities, that is, when a certain degree of disturbance or failure occurs in the grid, the wind turbines It can still maintain grid-connected operation and avoid the impact of large-scale off-grid on the grid. The IEC standard recommends the use of a circuit breaker switching reactor-type voltage drop device based on the principle of impedance voltage division, which actually generates a voltage drop at the grid-connected point of the wind turbine to detect the low-voltage ride-through capability of the wind turbine.

Contents of the invention

Aiming at the deficiencies of the prior art, the present invention provides a low-voltage ride-through control system and a control method thereof for a wind turbine, which is used to control a voltage drop generating device and conduct a low-voltage ride-through capability test on a wind turbine in a wind farm.

The present invention provides a control system for low-voltage ride-through test equipment for wind turbines, the test equipment is a voltage drop device, including a switch cabinet and a reactor; the improvement is that the control system includes a data acquisition system, a monitoring system and a central processing system; the central processing system is respectively connected with the data acquisition system and the monitoring system.

Wherein, the monitoring system includes an on-site monitoring system and a remote monitoring system; the on-site monitoring system and the remote monitoring system are respectively connected to the central processing system.

Wherein, the on-site monitoring system includes a safety chain system, a status signal indicating system and a reactor temperature measuring system;

The safety chain system is used to disconnect the power supply switch between the control system and the grid;

The status signal indicating system is used to judge the running status of the test equipment;

The reactor temperature measurement system monitors the temperature of the reactor in real time through 3 infrared temperature measurement probes.

Wherein, the state signal indicating system determines the operating state of the testing equipment by judging the opening and closing positions of the switches in the switch cabinet combination; the operating state of the testing equipment includes the operating state of entering the container, the preparation state of the wind turbine for grid connection, and the grid connection power generation of the wind turbine. status and system emergency stop status.

Wherein, the remote monitoring system realizes the monitoring of the wind turbine through the server and the LCD screen;

The LCD screen displays the secondary value of the grid voltage, the secondary value of the terminal voltage of the wind turbine and the real-time temperature of the reactor in real time;

When there is a safety failure, the LCD screen pops up an emergency alarm box to warn the operator to stop the test immediately and perform a safety check.

Wherein, the data collection system includes functions of data collection, data storage and export, data analysis and output;

The data collection system collects the electrical quantities and state quantities of the wind turbines, and transmits them to the central processing system.

Wherein, the central processing system performs calculation processing and logic control according to the data obtained from the data acquisition system and the monitoring system, and performs interactive transmission of test data and three-remote information with the remote monitoring system.

Among them, the logic of the central processing system includes the control logic of container entry operation, the control logic of wind turbine preparation grid connection, the wind turbine grid connection control logic and the start voltage drop test control logic;

The central processing system judges the state of the test equipment according to the set parameters, and adjusts the test equipment to the state of the wind turbine voltage drop through logic control.

Wherein, the central processing system includes an intelligent controller; the intelligent controller adopts an industrial-grade 32-bit bus microcontroller of Renesas Company.

Based on another purpose, the present invention provides a control method for the control system of the low-voltage ride-through test equipment for wind turbines, the improvement of which is:

When testing, the central processing system controls the combination of switch cabinets, realizes the input and withdrawal of the current-limiting reactor and the short-circuit reactor by controlling the circuit breaker, changes the state of the wind turbine into a state of voltage drop, and passes the on-site The monitoring system monitors the operating status of the switchgear combination, the real-time temperature of the reactor, the status of the safety chain system and the status signal indication, and transmits the monitored data to the central processing system; the data acquisition system collects the test data of the wind turbine and transmits it to the For the central processing system, through data analysis, it is judged whether the wind turbine has low-voltage ride-through capability.

Wherein, during the process of the central processing system controlling the combination of switch cabinets, the central processing system first judges the state of the test equipment, and adjusts the state of the wind turbine to the state of voltage drop through logic control.

Wherein, the state of the test equipment is divided into the operation state of entering the container, the state of preparing the wind turbine to be connected to the grid, the state of the wind turbine connected to the grid for power generation, and the state of emergency stop of the system.

Wherein, the logic control includes:

For the control logic of entering the container:

Open circuit breakers CB3, CB2 and CB1;

Disconnect the isolation switch S2 and S1;

Close the grounding switches G2 and G1; and

Close circuit breakers CB2 and CB1;

For the grid-connected control logic for wind turbines:

Disconnect the grounding switch G2 and G1;

Open circuit breakers CB3, CB2 and CB1;

Close the isolation switches S2 and S1; and

Close circuit breaker CB2;

For wind turbine grid-connected control logic:

Open circuit breaker CB3; and

Close circuit breaker CB1;

For the start voltage dip control logic:

Delay start test time t1;

Open circuit breaker CB2;

Delay current limiting reactor input time t2;

Close circuit breaker CB3;

Delayed short-circuit reactor input time t3;

Open circuit breaker CB3;

Delay current-limiting reactor withdrawal time t4; and

Close circuit breaker CB2.

Compared with the prior art, the beneficial effects of the present invention are:

(1) The control system has a high degree of automation. The system realizes the automatic control of different test stages through logical operation. The whole test process is simple and efficient, which can effectively avoid human misoperation and reduce test risk.

(2) The control system has strong stability. The control system monitors the real-time operation of key components such as switchgear combinations and reactor combinations in the test equipment, reliably prevents operation failures, and improves the stability of the test equipment.

(3) The control system has a strong safety protection function. The control system is designed with a rigorous safety chain protection system, and strict safety protection measures have been taken from both active and passive aspects through status indication and emergency shutdown of the safety chain.

Description of drawings

Fig. 1 is a primary main wiring diagram of a voltage drop device for a wind turbine in the prior art.

Fig. 2 is a schematic diagram of the control system of the wind turbine low voltage ride through test equipment provided by the present invention.

Fig. 3 is the design of the front panel of the intelligent controller provided by the present invention.

Fig. 4 is the first automatic control logic flow chart provided by the present invention.

Fig. 5 is the second flow chart of the automatic control logic provided by the present invention.

Fig. 6 is the third flow chart of the automatic control logic provided by the present invention.

Fig. 7 is the fourth flow chart of the automatic control logic provided by the present invention.

FIG. 8 is a timing diagram of the drop test action provided by the present invention.

Fig. 9 is a logic diagram of the safety chain system provided by the present invention.

Detailed ways

The specific implementation manners of the present invention will be further described in detail below in conjunction with the accompanying drawings.

The primary main wiring diagram of the voltage drop device for wind turbines in this embodiment is shown in Figure 1, which mainly includes switch cabinets and reactors, and the reactors include short-circuit reactors and current-limiting reactors. This embodiment provides a control system and a control method of a low-voltage ride-through test device (that is, a voltage drop device) for a wind turbine, and performs a low-voltage ride-through capability test on the wind turbine.

The control system of the low-voltage ride-through test equipment for wind turbines logically includes four parts: a data acquisition system, an on-site monitoring system, a remote monitoring system, and a central processing system, as shown in Figure 2. The central processing system is respectively connected with the data acquisition system, on-site monitoring system and remote monitoring system; the data acquisition system collects the electrical quantity and state quantity of the wind turbine unit under test; the on-site monitoring system monitors and indicates the operating status of the test equipment; the central processing The system collects the operating status of wind turbines and test equipment and performs centralized calculation and processing, and at the same time, it performs interactive transmission of test data and three-remote information with the remote monitoring system.

in:

1 Central processing system design

The intelligent controller of the central processing system realizes the collection of the operation state information of the test equipment and the operation state information of the test wind turbine, and realizes the intelligent logic control of the test equipment through the logical judgment and processing of the corresponding information.

1.1 Hardware Design of Intelligent Controller of Central Processing System

The core of the intelligent controller hardware platform adopts the advanced industrial-grade 32-bit bus microcontroller of Renesas Company, which has high integration, strong anti-interference ability, fast operation speed and low power consumption. The controller uses an independent 14-bit A/D conversion sampling chip from ADI Company to realize analog quantity acquisition.

In terms of structural design, the strong and weak current circuits of the boards inside the controller, the input and output circuits are reasonably arranged, and the groove rail plug-in installation is adopted to facilitate the replacement and maintenance of the boards. The high-shielding potential integrated chassis is adopted, and the electrical isolation and electromagnetic shielding design conforms to international standards, ensuring that the hardware system of the device has a very high anti-interference ability. It adopts high-resolution LCD screen display with high definition and comprehensive and intuitive display content; the membrane buttons are beautiful and durable, making real-time observation, maintenance and operation convenient and feasible on site. The front panel design of the smart controller is shown in Figure 3.

The performance parameters of the intelligent controller are as follows:

1. Communication interface: RS232;

2. 6 channels of 0-100V voltage signal;

3. 6 channels of 4-20mA current signal;

4. 20 switch input channels;

5. 36 switch output channels;

6. Analog sampling accuracy is 0.5%;

7. Channel step response time <10ms; channel synchronization time <1ms;

1.2 Central processing system intelligent controller software design

The software design of the intelligent controller of the central processing system fully covers the application requirements of various aspects of the test equipment. From the perspectives of safety, stability, convenience, and practicality, it has made an in-depth and perfect architecture design from the safety lock protection to the automatic logic control.

In order to realize the automatic control of the test process, four sets of automatic control logics are embedded in the intelligent controller operating system, including: "container entry operation control logic", "wind turbine preparation grid connection control logic", "wind turbine grid connection control logic" , "Start the voltage drop test control logic". According to the test setting parameters, the automatic control system judges the state of the test equipment, automatically adjusts the test equipment to the set operating state through the control logic, and finally automatically completes the entire low voltage ride-through test process.

2 Design of local monitoring system

The local monitoring system mainly realizes the information interaction and control with the switchgear combination and the reactor. On-site monitoring system includes safety chain system, status signal indication system and reactor temperature measurement system;

The on-site monitoring system collects the switch positions of all switch cabinet combinations in the voltage drop device, and can perform independent remote control on the switch cabinet on site. At the same time, the local monitoring system monitors the operating parameters of the switchgear insulation gas pressure, temperature, humidity, etc., and can actively intervene and adjust the temperature and humidity to maintain the operating environment of the switchgear.

The reactor temperature measurement system of the on-site monitoring system monitors the body temperature of the reactor in real time through 3 infrared temperature measurement probes. When the temperature of the reactor is too high, the local monitoring system will give an alarm and automatically terminate the operation of the test equipment to ensure the safe operation of the reactor. The model of its infrared temperature measuring probe can be IRTP300MS-TR.

The safety chain system of the local monitoring system includes 4 sets of automatic electronically controlled threshold switches and a set of emergency stop buttons. When the test equipment is running, after any misoperation triggers the action of the threshold switch, the safety chain system starts immediately, disconnects the power switch between the test equipment and the power grid, and separates the test equipment from the high-voltage power grid to ensure the safety of testers and test equipment. The emergency stop button is used for manual emergency cut-out operation under any circumstances, increasing the safety and controllability of the test equipment. The logic of the safety chain system is shown in Figure 9. The model of the threshold switch in this embodiment is Schneider XCE-145.

The status signal indication system is designed for the on-site monitoring system. By judging the opening and closing positions of each switch in the switch cabinet combination, the test equipment is divided into four operating states, namely "operating state of entering the container", "wind turbine ready to connect to the grid", " Fan grid-connected power generation status" and "system emergency stop status", and are indicated by four signal lights: green flashing, orange, red and red flashing respectively. Testers can judge the system running status in the test according to the signal lights and enhance the safety of test equipment. visibility. The status signal indication system of this embodiment is a signal indicator light, and its model is Schneider XVB-C.

3 Remote Monitoring System

Including servers and LCD screens, through the remote monitoring system, testers can monitor and control the test equipment away from the high-voltage test equipment, ensuring the absolute safety of testers from the level of geographical isolation.

The remote monitoring system interacts with the intelligent controller through the RS232 communication mode, and the communication system is stable and reliable. In order to reduce the impact of electromagnetic interference of high-voltage equipment on communication equipment, the remote monitoring system uses multimode optical fiber as the transmission medium to completely isolate electromagnetic interference and improve the anti-interference performance of the remote monitoring system.

In order to strive for convenient and practical operation, the remote monitoring software integrates all the real-time information in the control system into one main interface for display. The primary circuit diagram of the test equipment displayed on the main interface includes the opening and closing positions of all circuit breakers, isolation switches and grounding switches. Each switch position can be operated independently by remote control.

The main interface also includes:

(1) Real-time display of the dialog box of the secondary value of the 6-way voltage, which is used to judge the operating level of the grid voltage;

(2) Temperature boxes T1~T3 for real-time display of temperature, which are used to monitor the real-time temperature of the reactor, the main functional device of the test equipment, to prevent its over-temperature damage;

(3) The emergency alarm box is used to monitor the important signal status that affects the operation safety of the equipment. When a safety failure occurs, the alarm box warns the operator to stop the test immediately and conduct a safety inspection to ensure the safe operation of the test equipment;

(4) The intelligent controller software has designed an independent control dialog box to prevent misoperation. The logic control part of the control interface includes 4 kinds of logic automatic control operation modes, which execute different automatic logic control respectively, so that the test equipment can automatically complete the entire test action. In the drop test parameter setting box, the operator can set the operation time of each sequence in the automatic logic control, which is convenient for different types of drop tests.

4 Data Acquisition System

The main functions of the data acquisition system are as follows:

(1) Data collection. Adopt 24-bit high-speed data acquisition equipment with a sampling rate of up to 200KHz. The acquisition equipment is equipped with 16 acquisition channels to collect various data such as wind turbine current, voltage, wind speed, speed, pitch angle, and switch status. According to the characteristics of the collected data , the acquisition channel can independently set the filter type and passband range. The collected data can be monitored with multiple windows, and it has the function of moving the cursor to display the data. Through the mathematical calculation of the channel, various data types such as the processed real-time value, average value, and effective value can be displayed.

(2) Data storage and export. Level, time and frequency can be selected as the trigger signal to trigger and record the collected data. Trigger conditions can be selected from various trigger methods such as edge trigger, filter edge trigger, pulse width trigger, slope trigger, window trigger and combination of window and pulse width. It can also be triggered manually. Start file storage. Files can be output in various formats: Text, Excel, Flexpro, Matlab, Famos, Wave and other formats. The storage capacity is up to 500GB.

(3) Data analysis and output. All test data are stored in real time and can be replayed, selected, analyzed and printed.

The data acquisition system can be a sensor.

According to the above control system, this embodiment proposes a control scheme. When testing, the central processing system controls the combination of switch cabinets, and realizes the input and withdrawal of current-limiting reactors and short-circuit reactors by controlling circuit breakers. The network point produces a voltage drop state, and monitors the operating state of the switch cabinet combination, the real-time temperature of the reactor, the state of the safety chain system and the state signal indication through the on-site monitoring system, and transmits the monitored data to the central processing system; The data acquisition system collects the test data of the wind turbine and transmits it to the central processing system. Through data analysis, it is judged whether the wind turbine has low-voltage ride-through capability.

When the central processing system controls the combination of switch cabinets, the central processing system first judges the state of the test equipment, and adjusts to the voltage drop state through logic control.

The test equipment in this embodiment is divided into the operation state of entering the container, the state of preparing the wind turbine to be connected to the grid, the state of the wind turbine connected to the grid for power generation, and the state of emergency stop of the system. According to the corresponding state, the central processing system performs corresponding logic control to simulate the voltage drop of the wind farm. The logic control is shown in Figure 4-Figure 7, including:

For the control logic of entering the container:

Open circuit breakers CB3, CB2 and CB1;

Disconnect the isolation switch S2 and S1;

Close the grounding switches G2 and G1; and

Close circuit breakers CB2 and CB1;

For the grid-connected control logic for wind turbines:

Disconnect the grounding switch G2 and G1;

Open circuit breakers CB3, CB2 and CB1;

Close the isolation switches S2 and S1; and

Close circuit breaker CB2;

For wind turbine grid-connected control logic:

Open circuit breaker CB3; and

Close circuit breaker CB1;

For startup voltage dip control logic:

Delay start test time t1;

Open circuit breaker CB2;

Delay current limiting reactor input time t2;

Close circuit breaker CB3;

Delayed short-circuit reactor input time t3;

Open circuit breaker CB3;

Delay current-limiting reactor withdrawal time t4; and

Close circuit breaker CB2.

Through the above control, the action sequence of the reactor of the voltage drop device is shown in Fig. 8 . After simulating the voltage drop phenomenon of the wind farm, the data acquisition system collects the relevant test data of the wind turbine, including the three-phase voltage and three-phase current at point R on the rotor side of the generator, the DC voltage at point C on the DC side of the converter, and the Three-phase current at point L of the side converter, three-phase voltage and three-phase current at point T of the wind turbine outlet, wind speed signal Vwind, pitch angle of the wind turbine, mechanical speed ωr of the generator, grid-connected switch S of the wind turbine Switch position signal, through data analysis, to judge whether the wind turbine has low voltage ride through capability.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: the present invention can still be Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention shall be covered by the scope of the claims of the present invention.

Claims (7)

1. A control system for low-voltage ride-through test equipment for wind turbines, the test equipment is a voltage drop device, including a switch cabinet and a reactor; it is characterized in that the control system includes a data acquisition system, a monitoring system and a central processing system ; The central processing system is connected with the data acquisition system and the monitoring system respectively; The monitoring system includes an on-site monitoring system and a remote monitoring system; the on-site monitoring system and the remote monitoring system are respectively connected to the central processing system; The on-site monitoring system includes a safety chain system, a status signal indicating system and a reactor temperature measuring system; The safety chain system is used to disconnect the power supply switch between the test equipment and the grid; The status signal indicating system is used to judge the running status of the test equipment; The reactor temperature measurement system monitors the temperature of the reactor in real time through 3 infrared temperature measurement probes; The central processing system performs calculation processing and logic control according to the data obtained from the data acquisition system and the monitoring system, and performs interactive transmission of test data and three-remote information with the remote monitoring system; The logic of the central processing system includes the control logic of container entry operation, the control logic of wind turbine preparation for grid connection, the control logic of wind turbine grid connection, and the control logic of start-up voltage drop test; The central processing system judges the state of the test equipment according to the set parameters, and adjusts the test equipment to the state of the wind turbine voltage drop through logic control. 2. control system as claimed in claim 1, is characterized in that, described state signal indication system determines the running state of test equipment by judging the on-off position of switch in switchgear combination; The running state of described test equipment includes Container operation status, wind turbine preparation grid connection status, wind turbine grid connection power generation status and system emergency stop status. 3. The control system according to claim 1, wherein the remote monitoring system realizes the monitoring of the wind turbine through a server and a liquid crystal screen; The LCD screen displays the secondary value of the grid voltage, the secondary value of the terminal voltage of the wind turbine and the real-time temperature of the reactor in real time; When there is a safety failure, the LCD screen pops up an emergency alarm box to warn the operator to stop the test immediately and perform a safety check. 4. control system as claimed in claim 1, is characterized in that, described data collection system comprises data collection, data storage and derivation, data analysis and output function; The data collection system collects the electrical quantities and state quantities of the wind turbines, and transmits them to the central processing system. 5. control system as claimed in claim 1 is characterized in that, described central processing system comprises intelligent controller; Described intelligent controller adopts industrial grade 32 bus microcontrollers of Renesas Company. 6. The control method of the wind turbine low voltage ride through test equipment control system according to claim 1, characterized in that, When testing, the central processing system controls the combination of switch cabinets, realizes the input and withdrawal of the current-limiting reactor and the short-circuit reactor by controlling the circuit breaker, changes the state of the wind turbine into a state of voltage drop, and passes the on-site The monitoring system monitors the operating status of the switchgear combination, the real-time temperature of the reactor, the status of the safety chain system and the status signal indication, and transmits the monitored data to the central processing system; the data acquisition system collects the test data of the wind turbine and transmits it to the For the central processing system, through data analysis, it is judged whether the wind turbine has low voltage ride-through capability; In the process of the central processing system controlling the combination of switch cabinets, the central processing system first judges the state of the test equipment, and adjusts the state of the wind turbine to the state of voltage drop through logic control; The state of the test equipment is divided into the container loading operation state, the wind turbine preparation grid connection state, the wind turbine grid connection power generation state and the system emergency stop state. 7. The control method according to claim 6, wherein the logic control comprises: For the control logic of entering the container: Open circuit breakers CB3, CB2 and CB1; Disconnect the isolation switch S2 and S1; Close the grounding switches G2 and G1; and Close circuit breakers CB2 and CB1; For the grid-connected control logic for wind turbines: Disconnect the grounding switch G2 and G1; Open circuit breakers CB3, CB2 and CB1; Close the isolation switches S2 and S1; and Close circuit breaker CB2; For wind turbine grid-connected control logic: Open circuit breaker CB3; and Close circuit breaker CB1; For the start voltage dip control logic: Delay start test time t1; Open circuit breaker CB2; Delay current limiting reactor input time t2; Close circuit breaker CB3; Delayed short-circuit reactor input time t3; Open circuit breaker CB3; Delay current-limiting reactor withdrawal time t4; and Close circuit breaker CB2.