具有无功和谐波补偿功能的并网逆变器设计

Design of Grid-tied Inverters with the Functions of Reactive and Harmonic Compensation

以正弦电流方式向电网传送有功电能的并网逆变器控制简单,但不能改善和控制电网中的电能质量。文中根据瞬时无功理论和谐波分解提取方法,提出了一种新型的并网逆变器:除了传送有功电能以外,还能够根据电网中的电能质量情况向电网注入相应的无功和谐波,以进行补偿和抑制。分别给出了工作于传送有功模式、无功补偿模式和谐波抑制模式下的相关信号提取及其控制方案,并进行了详细的仿真研究,仿真结果验证了所提出方案的正确性。

Grid-tied inverters which only deliver active power to the mains in the sine wave current way are simple to control.However, they cannot improve and control the power quality of the mains. This paper proposes a new kind of grid-tied inverter based on the instantaneous reactive power theory and harmonic detection algorithm. Besides the transmission of normal active current, the new grid-tied inverter can inject appropriate reactive and harmonic currents into the mains according to the quality of the mains. Consequently, the reactive power and harmonic current in the mains can be compensated. Control strategies and harmonic signal detection methods are derived for different operation modes such as the active power transmission mode, the reactive power compensation mode, and the harmonic current filtering mode. Detailed simulation results have verified the validity of the proposed methodology.