CAJ | 학술논문

微网中有可能存在电压谐波问题.设计具有能量转换和电压谐波治理的复合型逆变器有助于降低微网的成本.同时当多逆变器并联时,希望各逆变器能在基波和谐波域依照各自容量分配功率.现有方法是采用下垂控制和虚拟阻抗技术.首先建立包含谐波域的逆变器并网模型,阐述了谐波抑制的基本原理.然后讨论了设计逆变器的输出阻抗为阻性的方法.随后应用下垂控制策略,提出了逆变器基波和谐波的分频下垂控制器设计方法.最后通过PSCAD验证了该方法不仅能有效地抑制电压谐波,而且也能依照容量合理分配基波域和谐波域的功率.
미망중유가능존재전압해파문제.설계구유능량전환화전압해파치리적복합형역변기유조우강저미망적성본.동시당다역변기병련시,희망각역변기능재기파화해파역의조각자용량분배공솔.현유방법시채용하수공제화허의조항기술.수선건립포함해파역적역변기병망모형,천술료해파억제적기본원리.연후토론료설계역변기적수출조항위조성적방법.수후응용하수공제책략,제출료역변기기파화해파적분빈하수공제기설계방법.최후통과PSCAD험증료해방법불부능유효지억제전압해파,이차야능의조용량합리분배기파역화해파역적공솔.
Because there possibly lies voltage harmonics pollution in microgrids, it benefits to reduce system cost if inverters have compound functions of voltage harmonics suppression and electrical energy conversion. Moreover, when multi inverters operated parallel in the mircogrids, they are expected to share the power proportionally according to their capacities. In this respect, frequency dividing droop control strategy and inverter's virtual output impedance shaping technology are quite attractive methods to achieve this goal. In this paper, firstly inverter grid-connected model containing the harmonics components is built and voltage harmonics suppression principle is introduced. Then, the method of making inverters' output impedance resistive is discussed. Subsequently, with droop control theory, design of frequency dividing droop controller within fundamental and harmonic frequencies fields is presented out. At the last part of this paper, with PSCAD simulation tool, validity of proposed method is proved and satisfied performances are obtained in the respects of not only harmonics suppression but also proportional load sharing according to its capacity.