基于新型鲁棒下垂控制方法的光伏发电系统并网研究

doi:10.16180/j.cnki.issn1007-7820.2021.08.013

摘要/Abstract

摘要：

光伏发电系统具有易受环境和负载变化影响的特点,其在并网过程中会产生频率和功率波动问题,而传统PI控制方法反应速度慢且稳定性差。针对这一问题,文中提出了一种新型鲁棒下垂控制设计方法。该方法在双向互联变换器双闭环控制电流内环的控制结构中设计了一个积分滑模控制器。该控制器既能够快速平抑光伏发电系统在并网过程中产生的电压和频率波动,又能够保证不同环境条件下电力系统的稳定性。MATLAB/Simulink仿真结果表明,新型鲁棒下垂控制方法比传统PI控制方法反应更快且波动幅度下降近一半,更好地保证了电网在光伏发电系统并网后的持续稳定运行。

关键词: 光伏发电, 最大功率点跟踪, 扰动观察法, 交直流混合微电网, 双向互联变换器, 下垂控制, 滑模控制, MATLAB仿真

Abstract:

Photovoltaic power generation system is easy to be affected by the environment and load changes, which will generate frequency and power fluctuations in the process of grid connection. The traditional PI control method is slow in response and poor in stability. To solve this problem, a new robust droop control design method is proposed in this study. An integral sliding mode controller is designed in the double closed-loop current inner loop control structure of bi-directional interconnected converter. The designed controller can not only suppress the voltage and frequency fluctuation of photovoltaic power generation system in the process of grid connection, but also ensure the stability of power system in different environmental conditions. The simulation results in MATLAB/Simulink show that the new robust droop control method is faster than the traditional PI control, and the fluctuation amplitude is reduced by nearly half, which ensures the continuous and stable operation of the grid after the photovoltaic power generation system is connected to the grid.

Key words: photovoltaic power generation, MPPT, perturbation and observation, AC/DC hybrid microgrid, bi-directional interconnected converter, droop control, sliding mode control, MATLAB simulation

中图分类号:

TP273

闫振彬,郑柏超,周志勇. 基于新型鲁棒下垂控制方法的光伏发电系统并网研究[J]. 电子科技, 2021, 34(8): 79-86.

YAN Zhenbin,ZHENG Bochao,ZHOU Zhiyong. Research on Grid Connection of Photovoltaic Power Generation Systems Based on a New Robust Droop Control Method[J]. Electronic Science and Technology, 2021, 34(8): 79-86.

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模块名称	参数	参数描述	数值
交流电网侧参数	U_ac	电网电压	1 000 V
	f	电网频率	50 Hz
	R_ac	交流侧线路阻抗	0.150 0 Ω
	L_ac	交流侧线路感抗	0.450 0 mH
	P_ac1	交流负载1有功功率	1 000 W
	Q_ac1	交流负载1无功功率	500 Var
	P_ac2	交流负载2有功功率	800 W
	Q_ac2	交流负载2无功功率	800 Var
三相变压器	n₁/n₂(Δ-Y)	三相变压器变比	10 kV/0.400 0 kV
滤波器	C_f	滤波器电容	0.100 0
滤波器	L_f	滤波器电感	1
下垂控制参数	1/K_P	下垂增益	1/10×10^-3
下垂控制参数	1/K_q	下垂增益	1/20×10^-3
PI控制	K_P	PI增益	1
参数	K_I	PI增益	5
滑模控制参数	K₀	滑模增益	0.000 1
	K	滑模增益	0.800 0
	ε	滑模增益	0.100 0
直流侧参数	R_dc	直流侧线路阻抗	0.200 0 Ω
	P_dc1	直流负载1功率	1 000 W
	P_dc2	直流负载2功率	1 000 W
光伏发电模型参数	T_ref	温度参考值	25 ℃
	S_ref	光照强度参考值	1 000 W·m^-2
	I_sc	短路电流	14.880 0 A
	I_m	最大功率电流	13.880 0 A
	V_oc	开路电压	354 V
	V_m	最大功率电压	288 V