391 / 2017-04-24 18:42:24

Research on Intelligent Contactor of Distributed Wind Power System

4316,13575,13576,11916,13577

In recent years, with the development of smart grid and the rapid development of distributed power supply, the traditional switching device has been unable to solve the problem of power quality caused by distributed power system. Contactors for distributed wind power systems should have low voltage ride through capability，the so-called low voltage ride through means that when the distributed power supply voltage drops to 20% of the rated control voltage, the contactor can remain connected to more than 625ms, When the voltage drops to zero contactor can meet more than 20ms without breaking. However, the traditional contactor is not versatile, and the starting current several times to keep the current, iron loss caused a serious waste.
Aiming at these problems, this paper presents a new control scheme based on Buck-Boost transform circuit. Pulse width modulation (PWM) control and adaptive closed loop voltage feedback regulation are applied to the voltage applied across the contactor coil. The working principle and process of the system are introduced in detail and the validity of the design is verified. This scheme enables the contactor to realize the functions of energy-saving operation, wide operating voltage range, low voltage ride through and other characteristics. It can be widely used in distributed power system, which has good practical significance and market prospect.