基于Matlab/Simulink仿真的H级燃机发电机静态变频启动装置谐波分析

Harmonic Analysis of H Class Gas Turbine Generator Starting With Static Frequency Converter Based on Matlab/Simulink Simulation

随着燃气‒蒸汽联合循环发电技术不断发展,发电机容量和参数要求不断提升。H级燃气‒蒸汽联合循环发电机组的发电机需具备更为稳定、高效、安全的启动要求。为此,静态变频装置(static frequency converter,SFC)启动技术发展也迎来新的挑战。SFC启动技术精准、灵活、高效控制的同时,产生的谐波分量会对电源系统的电能质量有一定的影响。通过Matlab/Simulink建立H级燃机发电机SFC启动仿真模型,模拟发电机启动过程,观察系统参数变化,分析谐波分量占比。仿真结果显示,采用SFC启动可通过调节输出电流的频率和幅值,柔性提升发电机的转速,发电机启动受冲击小。但SFC内置大量非线性电气元件,会使大量谐波分量涌入系统之中,影响电能质量。因此,提出2种抑制谐波影响的SFC接入优化方案,即增设输入电抗器方案和输入电源改接发电机机端方案。通过仿真模型证实了2种方案都可有效抑制或减少谐波影响,满足电能质量要求。

With the development of gas-steam combined cycle power generation technology,the requirements of generator capacity and parameters are constantly improving.The generators of H class gas-steam combined cycle generator unit need to have more stable,efficient and safe starting requirements.It also stimulates improvement of static frequency converter(SFC)technology facing more challenge.SFC technology has displayed its advantages in controlling accurately,flexibly and efficiently.Meanwhile,SFC brings more harmonic components to influence the quality of power system.SFC start-up simulation model of H class gas turbine generator was built by Matlab/Simulink to simulate the generator start-up process,the evolvement of various parameters was researched and the proportion of harmonic components during the generator starting was analyzed.The simulation results show that the SFC start-up can increase the speed of the generator flexibly by adjusting the frequency and amplitude of the output current,and the impact of the generator start-up is small.However,large numbers of nonlinear electrical components built in SFC will cause higher proportion of harmonic components appear in power system and influence power quality.Therefore,two optimization schemes for SFC access were proposed to suppress harmonic effects,which are the scheme of adding input reactor before SFC and the scheme of changing generator end of input power supply.Through the simulation,it was proved that the two schemes can effectively suppress or reduce the harmonic effect and meet the requirements of power quality.