基于ORC中发电机逆变系统的研究

Research of Generator Inverter System Based on ORC

对有机朗肯循环(ORC)低温余热发电中整个发电逆变系统进行了设计。首先根据整个发电系统对于发电机的性能要求和尺寸限制,给出发电机设计所需的额定参数及主要尺寸,对电机进行了电磁设计研究,验证了所设计的发电机满足感性负载下的电压和功率要求。其次针对双极性正弦脉宽调制(SPWM)产生丰富的高次开关谐波,对逆变侧输出二阶低通滤波器进行了设计,选择合理的参数滤除高次谐波。针对发电机输出电压波动设计了电压和电容电流反馈双闭环,通过建模整定反馈环路参数,绘制系统环路伯德图验证系统的稳定性和动态性能。最后设计一台三相四线制离网发电逆变器进行实验,结果证明所设计系统的输出电压波形畸变率小,整个系统在突变负载时满足稳态和动态调节性能的要求。

The entire power inverter system in Organic Rankine Cycle （ORC） waste heat power generation was designed. Firstly, this paper gave the generator design required nominal parameters and main dimensions based on the entire power system performance requirements and size constraints of the generator, made electromagnetic design studies of the motor, verified that the generator designed meet the voltage and power requirements with inductive loads. Secondly, for bipolar sinusoidal pulse width modulation （spwm） producing a rich high order switch harmonics, this paper designed the inverter output side＇s the second-order low- pass filter, made a reasonable choice of parameters to filter out higher harmonics. For generator output voltage tremendous mutation, designed voltage and capacitance current double closed loop feedback, adjusted feedback loop parameters by modeling, ploted loop Bode diagram to verify system stability and dynamic performance. Finally, designed a three-phase four-wire system off-grid inverter to go on experiment. The results prove that the designed system have a small output voltage waveform distortion rate. The whole system meets the steady-state and dynamic performance requirements when load changes suddenly.