光伏并网变压器紧急调控域频率自动控制方法  

Automatic frequency control method for emergency regulation domain of photovoltaic grid connected transformers

作　　者：陈飞 徐佳宁 尹兴隆 施辉选 张维 CHEN Fei;XU Jianning;YIN Xinglong;SHI Huixuan;ZHANG Wei(Yunnan Power Grid Co.,Ltd.,Kunming Yunnan 650200,China;Chuxiong Power Supply Bureau of Yunnan Power Grid Co.,Ltd.,Chuxiong Yunnan 675000,China)

机构地区：[1]云南电网有限责任公司,昆明650200 [2]云南电网有限责任公司楚雄供电局,云南楚雄675000

出　　处：《自动化与仪器仪表》2025年第3期279-283,共5页Automation & Instrumentation

基　　金：南方电网有限公司科技项目资助“基于云边融合的新型电力系统运行调度支撑技术研究与应用”(YNKJXM 20220186)。

摘　　要：在光伏并网系统的运行过程中,光照的随机变化导致光伏输出产生波动性负载。这种波动在逆变器的作用下,会导致电网频率波动增大和变压器域频率信号中谐波含量增加。当谐波分量达到一定规模时,会干扰当前的控制策略,导致频率调节不稳定、功率质量下降等问题。因此,研究光伏并网变压器紧急调控域频率自动控制方法。通过混叠补偿离散小波变换对变压器信号展开分解处理,并利用连续小波分析得到的子频带信号,提取其中的谐波分量,计算谐波分量的相位、幅值与频率,实现对谐波的检测。设计PIR控制器来抑制信号中存在的谐波分量,减少谐波对变压器频率控制的干扰。建立变压器频率的PI控制器,实现对变压器的无功功率和有功功率的解耦控制,以保证系统运行的稳定性和功率质量。通过电压前馈控制方法获得变压器电压的前馈控制量,在紧急调控域内控制变压器的电压,进而控制其频率。实验结果表明,所提方法可有效将信号中存在的谐波分量检测出来,并有效抑制了谐波,提高了频率控制的稳定性和效果。During the operation of the photovoltaic grid-connected system,the random change of light causes the photovoltaic output to generate fluctuating loads.This fluctuation will lead to an increase in the frequency fluctuation of the grid and an increase in the harmonic content of the frequency signal in the transformer domain under the action of the inverter.When the harmonic component reaches a certain scale,it will interfere with the current control strategy,resulting in problems such as unstable frequency regulation and power quality degradation.Therefore,the automatic frequency control method of photovoltaic grid-connected transformer in the emergency control domain was studied.The transformer signal is decomposed by aliasing compensation discrete wavelet transform,and the sub-band signal obtained by continuous wavelet analysis is used to extract the harmonic components,and the phase,amplitude and frequency of the harmonic components are calculated to realize the detection of harmonics.The PIR controller is designed to suppress the harmonic components present in the signal and reduce the interference of harmonics on the frequency control of the transformer.The PI controller of the transformer frequency is established to realize the decoupling control of the reactive power and active power of the transformer to ensure the stability and power quality of the system operation.The feedforward control quantity of transformer voltage is obtained through the voltage feedforward control method,and the voltage of the transformer is controlled in the emergency regulation domain,and then its frequency is controlled.Experimental results show that the proposed method can effectively detect the harmonic components in the signal,effectively suppress the harmonics,and improve the stability and effect of frequency control.

关 键 词：光伏并网 混叠补偿离散小波变换 变压器 谐波检测 频率控制 

分 类 号：TN464[电子电信—微电子学与固体电子学]