光伏并网发电及无功补偿的统一控制

针对常规光伏并网发电系统逆变主电路的结构特点,提出了将无功功率补偿与光伏并网发电相结合的新型控制方案,使光伏并网发电系统在向电网提供有功电能的同时也能够提供电网所需的无功电能,从而简化系统结构,提高供电能力,并节省设备投资.文中详细分析了系统控制结构、瞬时无功检测、并网电流的合成及并网电流的跟踪控制方法.系统以DSP数字信号处理器为基础,在30kVA光伏并网功率调节器实验样机中成功地实现了光伏并网发电和无功功率补偿的统一控制.

Unitive Control of PV Grid Connected Generation and Reactive Compensation

For the characteristics of the inverter main circuits normally used in photovoltaic grid-connected systems, a novel control strategy is proposed, in which photovoltaic grid connected generation is combined with reactive power compensation. The photovoltaic grid-connected system can provide not only active power but also reactive power needed by reactive loads and saves the investment of the equipment. The control algorithm of reactive power applies the concept of the instantaneous p-q power theory and the converter DC source, which is supplied by solar array, is tracked by searching the maximum power point (MPP). Combination of grid-connected current and current tracking are also discussed. The proposed control method of current is analyzed in abc coordinate. The uniformed control of reactive power compensation and photovoltaic grid-connected generation has been implemented in the prototype of 30kVA photovoltaic grid-connected power conditioner based on digital signal processor (DSP) successfully.