The wind turbine control unit (WPCU) is the control core of each wind turbine and is distributed in the tower and nacelle of the unit. Due to the harsh on-site operating environment of wind turbines, the reliability of the control system is very high. The wind power control system is specially designed for the operation needs of large wind farms and should have extremely high environmental adaptability and anti-electromagnetic interference capabilities. The system structure is as follows:
The on-site control station of the wind power control system includes: tower main controller cabinet, nacelle control station cabinet, pitch system, converter system, on-site touch screen station, Ethernet switch, on-site Bus communication network, UPS power supply, emergency shutdown backup system, etc. The network structure of the wind power control system is shown in Figure 1:
1. Tower control station
The tower control station, that is, the main controller cabinet, is the core of wind turbine equipment control. Including controllers, I/O modules, etc. The controller hardware adopts a 32-bit processor, and the system software adopts a strong real-time operating system. Various complex main control logics of the operating unit communicate in real time with the cabin controller cabinet, pitch system, and converter system through the field bus. In order to make the unit run in the best condition.
The controller is configured using feature-rich and user-friendly configuration software, using a configuration method that complies with the IEC61131-3 standard, including: function diagram (FBD), instruction list (LD), and sequential functions. Block (SFC), ladder diagram, structured text and other configuration methods.
2. Engine room control station
The engine room control station collects signals such as temperature, pressure, rotation speed and environmental parameters measured by the unit's sensors, and communicates with the unit's main control station through the field bus. The main control station The machine controls the frame through the engine room to realize the yaw, unmooring and other functions of the unit. In addition, it also controls various auxiliary motors, oil pumps and fans in the engine room to make the unit work in the best condition.
3. Pitch system
Large-scale wind turbines above the MW level usually use hydraulic pitch systems or electric pitch systems. The pitch drive system is controlled by the front-end controller, which is the execution unit of the main controller. It uses CANOPEN to communicate with the main controller to adjust the pitch of the three blades to work optimally. state. The pitch system has a backup power system and safety chain protection to ensure emergency shutdown in critical conditions.
4. Converter system
Large-scale wind turbines currently generally use high-power converters to achieve conversion of power generation energy. The converter system communicates with the main control through fieldbus It communicates with the device to realize the adjustment of the unit's speed, active power and reactive power.
5. On-site touch screen station
The on-site touch screen station is an on-site operation station for unit monitoring. It realizes functions such as local parameter setting, equipment debugging, and maintenance of wind turbine units. It is an important part of unit control. The system's on-site host computer operator station.
6. Ethernet switch (HUB)
The system uses industrial-grade Ethernet switches to connect the controller of a single unit, the on-site touch screen and the remote control center network. The on-site cabinet is connected using ordinary twisted pairs, and the remote control room host computer is connected using optical cable.
7. Field communication network
The main controller has various types of field bus interfaces such as CANOPEN, PROFIBUS, MODBUS, and Ethernet, which can be configured according to the actual needs of the project.
8. UPS power supply
UPS power supply is used to ensure the power supply of the unit control system, emergency protection system and related execution units when the external power supply is cut off.
9. Backup emergency safety chain system
The backup emergency safety chain system is independent of the hardware protection measures of the computer system. Even if an abnormality occurs in the control system, it will not affect the normal operation of the safety chain. . The safety chain is a circuit that connects abnormal faults that may cause fatal damage to the wind turbine in series. When the safety chain is activated, it will cause an emergency shutdown and the unit will be disconnected from the grid, thus ensuring the safety of the unit to the greatest extent.
All wind turbines are connected to the host computer operator station in the main control room through optical fiber Ethernet to realize remote monitoring of the entire wind farm. The host computer monitoring software should have the following functions:
①The system has a friendly control interface.
When compiling the monitoring software, the requirements for wind farm operation and management were fully taken into consideration, and a Chinese menu was used to make the operation simple and provide convenience for the management of the wind farm as much as possible.
② The system displays the operating data of each unit, such as the instantaneous power generation, cumulative power generation, number of power generation hours, wind wheel and motor speed, wind speed, wind direction, etc. of each unit. These data are transferred into the host computer and displayed on the monitor. If necessary, they can also be displayed visually in the form of curves or charts.
③The system displays the operating status of each wind turbine, such as start-up, parking, direction adjustment, manual/automatic control, and operation of large/small generators. Through the status of each wind turbine, you can understand the status of the entire wind farm. Operation status.
④The system can promptly display the faults that occur during the operation of each unit. When a fault is displayed, the type and time of occurrence of the fault can be displayed so that operators can deal with and eliminate the fault in a timely manner to ensure the safety and continuous operation of the wind turbine.
⑤The system can achieve centralized control of wind turbines. The attendant in the centralized control room only needs to operate the corresponding keys marked with a certain function to change the setting status and control the lower computer. Such as starting, stopping and turning left and right, etc. However, such operations have certain permissions to ensure the operational safety of the entire wind farm.
⑥System management. The monitoring software has the functions of scheduled printing and manual instant printing of operating data, as well as automatic fault recording, so that historical records of wind farm operating conditions can be viewed at any time.