ACTIVE VOLTAGE CONTROL FOR DFIG-BASED WIND FARM INTEGRATED POWER SYSTEM BY COORDINATING ACTIVE AND REACTIVE POWERS
Abstract : Large-scale wind farms are generally integrated by long-distance transmissions, but power grids cannot sufficiently support the access point voltage of these wind farms. The access point voltage undergoes a stability problem under wind speed variations. However, the reactive power compensation device cannot reconcile the requirements of response speed and compensation capacity. Despite their fast power decoupling control, the reactive power capability of doubly fed induction generators is restricted by active power output. To satisfy the reactive power demand of system under wind speed variations, coordinating the reactive power capability and active power output of wind farm is the key solution, based on which a novel active control idea is proposed. The reactive power capability of wind farm and the reactive power demand of system are both studied, and the controllable conditions of access point voltage are analyzed. Active voltage control strategies, including active adjustment of reactive power reference, active speed control, and active pitch angle intervention according to wind speed ranges, are proposed. In the simulation, the method is verified to adequately consider the reactive power demand, and excavate the wind farm reactive power capability. The method also effectively suppresses the change of grid voltage under wind speed variations.
Long-distance transmissions are commonly used to connect large-scale wind farms, however power networks cannot handle the access point voltage of these wind farms. Under wind speed fluctuations, the access point voltage has a difficulty with stability. The reactive power compensation device, on the other hand, is unable to meet both the response speed and the compensation capacity criteria. The reactive power capabilities of doubly fed induction generators are limited by active power output, notwithstanding their quick power decoupling control. This review is based on a variety of unique active control ideas.
The existing system has DC-DC boost converter method it required mppt , so not reliable.
converter circuits has delay the process performance.
Maintenance is poor compared to proposed system.
The reactive power compensation device, on the other hand, is unable to meet both the response speed and the compensation capacity criteria. The reactive power capabilities of doubly fed induction generators are limited by active power output, notwithstanding their quick power decoupling control. This review is based on a variety of unique active control ideas. Coordinating the reactive power capability and active power output of the wind farm is the main solution for satisfying the reactive power demand of the system under wind speed variations. The wind farm's reactive power capability and the system's reactive power demand are also investigated, as are the controllable circumstances of access point voltage. Active voltage control solutions are proposed, including active reactive power reference modification, active speed control, and active pitch angle intervention based on wind speed ranges. The approach also efficiently reduces the change in grid voltage caused by variations in wind speed
Over all efficiency increased and system cost get decreased.
Micro controller is that it can allow for easy feedback to control the power flowing through the load.
PWM is used extensively as a means of powering AC devices with a DC power source. A DC voltage source can be made to look like an AC signal across a load by altering the duty cycle of the PWM signal.
These system can achieve inverter and produce more power with high efficiency than the DFIG feeding.
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