【摘要】 提出了一种新的基于分布式并网发电系统的主动式孤岛检测方法,进行了仿真和实验研究。在PWM正弦调制波前后半周期产生一个微小的不对称,使并网逆变器输出电流也产生不对称,从而引起逆变器输出功率在连续的两个半周期内产生规律性的变化。并网时,输出功率的变化并不明显,而一旦孤岛出现时,输出功率的变化将导致并网公共点(PCC)频率的变化,以该频率的变化为依据,实现分布式发电系统的孤岛检测。在光伏并网发电系统的实验平台上进行实验验证,结果表明,该方法能有效检测出孤岛,且算法简单,易于实现。更多还原

【Abstract】 In the paper a novel active islanding detection algorithm is proposed based on Simulation and experiment. If the modulation sinusoidal waveform of the DSP controller presents a slight asymmetry, the output current of the inverter would reveal the same amount of asymmetry, and then the output power will be keep a regular change between two consecutive half-cycle. When in grid-connected scenario, the change of output power is insignificant; however, once the islanding event takes place, the frequency of PCC(the point of common coupling) will be change owing to the change of output power. An appropriate use of this change of frequency can be a useful indicator for the identification of islanding. The experimental results demonstrate effectiveness and easily realizafion of the proposed algorithm.更多还原