新能源并网谐振过电压分析

Resonant Overvoltage Analysis of Renewable EnergyGrid-connected System

基于新能源发电技术的快速发展,新能源发电所占比例呈逐年增大的趋势。新能源通过逆变装置接入后会给电力系统注入谐波,当其大规模并网后谐波含量丰富,可能会有谐振过电压的潜在风险。首先,针对光伏并网系统建立谐波数学模型,对单个新能源场站接入系统进行谐波分析,分析逆变器参数、线路参数及电网等效阻抗对谐振后系统电压产生的影响;然后,对多个新能源接入系统进行谐波分析,探究新能源不同规模接入时系统谐振变化规律及对系统电压造成的影响。

Based on the rapid development of renewable energy generation technology,the proportion of renewable energy generation is increasing year by year.And renewable energy will introduce harmonics into power system after being integrated through inverters.When renewable energy is linked to the grid on a large scale,the harmonic content is abundant and there may be a possible risk of resonant overvoltage.Firstly,a harmonic mathematical model is established for photovoltaic grid-connected system.Then,harmonic analysis on a single renewable energy site access system is carried out,and the impact of inverter parameters,line parameters,and grid equivalent impedance on system voltage after resonance is analyzed.And harmonic analysis on a variety of renewable energy access systems is also carried out to investigate the resonance variation pattern of renewable energy access at various scales and its impact on system voltage.