For the distributed small wind farms, an improved reduced matrix converter (RMC) structure is proposed. Its features are that the connection of directly-driven permanent synchronous generators (PMSG) are DC parallel and DC-DC structure with high frequency transformer is used to rise the DC bus voltage. The use of DC parallel reduces the randomness and volatility of wind power and has the smaller impact on the power grid voltage and the frequency. While the DC-DC boost structure replaces converter station, it is more suitable for distributed small wind farm. To effectively implement the generators to separate or parallel power grid, this paper designs the instantaneous sampling of the wind generator voltage to judge whether it is connected to the DC bus. The simulation models of a set of PMSG, PWM rectifier, circuit breaker and DC-DC with high frequency transformer are established based on Matlab/Simulink simulation platform. The simulation analyses that 1 or 2 generators separate or parallel DC bus and voltage boost in the case of the bus having 2, 5 or 8 generators are carried out. The simulation results show that the proposed model can achieve 1 or 2 wind generators to separate or parallel DC bus and voltage boost under ideal conditions, and it has a better effect when 7 generators run.%针对分散式小型风力发电场,提出了一种改进的RMC(Reduced matrix converter)结构.其特点为:永磁直驱风力发电机之间进行直流并联,母线电压经过含高频变压器的DC-DC结构进行升压.采用直流并联,减少了风力发电的随机性和波动性,对电网电压、频率的影响较小;而DC-DC升压结构代替换流站,较适用于分散式小型风力场.为有效实现发电机的切、并网,设计了对发电机输出电压瞬时采样,来判断发电机整流器侧是否连接到直流母线的断路器模型.基于Matlab/Simulink仿真平台搭建了一组永磁直驱风力发电机、PWM整流器、断路器及含高频变压器的DC-DC仿真模型,并进行了1或2台发电机在母线已并有2、5或8台发电机的情况下切、并直流母线与升压的仿真分析.结果表明,在理想状态下,该模型可以实现1或2台的风力发电机切、并直流母线与升压,且7台运行时效果较好.
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