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微网孤岛模式下多机并联的控制常采用下垂控制策略.但该策略所提出的解耦控制不适用于线路阻抗不以抗性为主的微网,即上述微网在该控制策略下的安全运行存在隐患.为解决该问题,文中从下垂控制原理出发,对传统下垂控制进行改进,提出带有电压补偿环节的“虚拟电抗法”,以实现在功率按容量分配的同时,电压不出现大幅跌落.此外,针对传统下垂控制中大负荷或大功率微源投切时的频率越限问题,提出“以曲代直”的“反S”下垂控制策略,给出“反S”型函数所应满足的条件,并仿真验证该策略的有效性.在比较高次幂、指数型和对数型3种“反S”型函数的基础上,从理论角度论证对数型“反S”下垂控制的合理性.“,”Droop control strategy is usually used in multi-parallel generators in the island mode of microgrids.But the decoupling control method proposed in the strategy is not suitable for the microgrids whose line reactance is not far greater than resistance.In other words,the strategy has troubles in the control of these microgrids' operation.To solve the problem,the control principle was analyzed and the droop control strategy was improved by virtual reactance method with a voltage compensation unit.In this way,power load was distributed according to DGs' capacity and the voltage would not drop sharply.In addition,to solve the frequency over-limitation resulted by the switching of heavy load or large-capacity DGs,An inverted-S droop control strategy and related requirement of inverted-S shape functions were proposed.The feasibility of inverted-S droop control strategy was verified by simulation.Besides,comparing three kinds of satisfying inverted-S shape functions,the control advantage of the logarithmic inverted-S shape function was demonstrated by math deduction.