柴油发电机组带脉冲负载非线性度评价方法研究

Research on evaluation method of nonlinearity of diesel generator set with impulse load

对于以柴油发电机组为主要电源的独立小容量电力系统,负载的脉冲功率特性将导致系统电压波形严重畸变和频率剧烈波动,干扰其它负载工作,影响设备正常运行,甚至引起系统保护跳闸。本文在系统交流频率、电压相对偏差率和直流电压波动率的基础上,提出了系统非线性度指标及其计算方法。试验结果表明,当脉冲负载工作占空比低于0.4时,系统非线性度随占空比的增大而增大;当占空比高于0.7时,系统非线性度随占空比的增大而减小;系统非线性度最大值出现在占空比为0.4至0.7之间。

For an independent small-capacity power system with diesel generator sets as the main power source,the characteristics of the impulse power load will cause serious distortion of voltage waveform and severe frequency fluctuations, interferes with the work of other loads or affects the normal operation of the equipment of the system, and even causes its protection trip. Based on relative deviation rates of AC frequency and voltage and DC voltage fluctuation rate, this paper proposes nonlinearity index and its calculation method for the system. The test results show that when the duty cycle of the pulse load is lower than 0.4, the system nonlinearity increases with the increase of the duty cycle;when the duty cycle is higher than 0.7, the system nonlinearity decreases with the increase of the duty cycle;the maximum value of system nonlinearity appears in a certain duty cycle between 0.4 and 0.7.