Fault Ride-Through Control Strategy of Virtual Synchronous Generator Based on Joint Control of Power Loop and Current Loop

doi:10.12096/j.2096-4528.pgt.24070

Abstract

Abstract:

Objectives The virtual synchronous generator (VSG) will suffer from power angle instability and cannot suppress the fault over-current when voltage drop faults in the power grid, posing a threat to the safe and stable operation of system. In order to solve these problems, based on the output characteristics of VSG under power grid faults, a VSG fault ride-through strategy based on joint control of power loop and current loop was proposed. Methods During the period of voltage drop in the power grid, the proposed strategy stabilizes transient power angle by adjusting the active power command value, suppresses fault current by freezing the reactive power loop and adding virtual resistor. An improved reactive current control is adopted, which can provide necessary reactive power support for the power grid by outputting reactive compensation current during grid faults, and suppresses reactive power oscillations by outputting reactive recovery current during grid recovery period. Finally, the proposed strategy is simulated and verified on the MATLAB/Simulink simulation platform. Results After adopting the proposed strategy, the transient impulse current of VSG is effectively suppressed, the steady-state fault current is within the safety threshold, and the appropriate reactive power is output. Conclusions This control strategy effectively solves the problems of fault overcurrent and reactive power exceeding the limit of VSG during voltage drop in the power grid, which is beneficial for the safe operation of the power grid during faults and the grid connected operation of VSG after fault recovery.

Key words: power grid, distributed generation, new energy, virtual synchronous generator (VSG), power angle stability, fault current suppression, reactive power support

CLC Number:

TM 712

Kai SHI, Yifan GONG, Peifeng XU, Yi DU, Yuxin SUN, Mingwei REN. Fault Ride-Through Control Strategy of Virtual Synchronous Generator Based on Joint Control of Power Loop and Current Loop[J]. Power Generation Technology, 2025, 46(6): 1231-1239.

Figures/Tables 12

Fig. 1 Main circuit of system and control structure of VSG

Fig. 2 VSG equivalent circuit diagram under fault conditions

Fig. 3 Schematic diagram of improved fault ride-through control

Fig. 4 Improved voltage and current loop diagram

Tab. 1 Main simulation parameters

参数	数值
电网电压U_g/V	311
直流电压U_dc/V	600
额定频率f_n/Hz	50
滤波电感L/mH	3.2
线路电感L_g/mH	0.8
滤波电容C/μF	10
转动惯量J/(kg/m²)	0.058
惯性系数K/(A∙s)	6.5
阻尼系数D_p	1 590
无功下垂系数D_q	320
虚拟电阻R_v/Ω	1.2

Fig. 5 Grid voltage

Fig. 6 VSG output current

Fig. 7 Active power under conventional VSG control

Fig. 8 Reactive power under conventional VSG control

Fig. 9 Improved output current and its local amplification

Fig. 10 Active power under the improved control

Fig. 11 Reactive power under the improved control

References 20

[1]	刘凯诚，钟鸣，曾平良，等．考虑分布式可再生电源和储能的智能配电网可靠性评估综述[J]．电测与仪表，2021，58(7)：1-11．
	LIU K C， ZHONG M， ZENG P L，et al ．Review on reliability assessment of smart distribution networks considering distributed renewable energy and energy storage[J]．Electrical Measurement & Instrumentation，2021，58(7)：1-11．
[2]	REN M W， LI T， SHI K，et al ．Coordinated control strategy of virtual synchronous generator based on adaptive moment of inertia and virtual impedance[J]．IEEE Journal on Emerging and Selected Topics in Circuits and Systems，2021，11(1)：99-110． doi:10.1109/jetcas.2021.3051320
[3]	杨旭红，姚凤军，郝鹏飞，等．基于改进型RBF神经网络的VSG转动惯量自适应控制[J]．电测与仪表，2021，58(2)：112-117．
	YANG X H， YAO F J， HAO P F，et al ．Adaptive inertia control for VSG based on improved RBF neural network[J]．Electrical Measurement & Instrumentation，2021，58(2)：112-117．
[4]	郭亦宗，郭创新．基于虚拟同步发电机的微电网并离网安全控制策略[J]．发电技术，2020，41(6)：650-658．
	GUO Y Z， GUO C X ．Security control strategy of micro-grid between grid-connected and off-grid based on virtual synchronous generator[J]．Power Generation Technology，2020，41(6)：650-658．
[5]	钱乙卫，田浩，刘财华，等．考虑概率分布的分布式光伏无功下垂控制策略[J]．发电技术，2024，45(2)：273-281．
	QIAN Y W， TIAN H， LIU C H，et al ．Droop control strategy of distributed photovoltaic reactive power considering probability distribution[J]．Power Generation Technology，2024，45(2)：273-281．
[6]	徐玉韬，冯起辉，谈竹奎，等．考虑转供与重构协同的多端柔性互联配电网供电恢复策略[J]．电工技术学报，2024，39(9)：2696-2709．
	XU Y T， FENG Q H， TAN Z K，et al ．Optimal power restoration strategy for multi-terminal flexible interconnected distribution networks based on flexible interconnection device and network reconfiguration[J]．Transactions of China Electrotechnical Society，2024，39(9)：2696-2709．
[7]	刘建伟，李学斌，刘晓鸥．有源配电网中分布式电源接入与储能配置[J]．发电技术，2022，43(3)：476-484． doi:10.12096/j.2096-4528.pgt.21068
	LIU J W， LI X B， LIU X O ．Distributed power access and energy storage configuration in active distribution network[J]．Power Generation Technology，2022，43(3)：476-484． doi:10.12096/j.2096-4528.pgt.21068
[8]	XIONG X L， WU C， BLAABJERG F ．Effects of virtual resistance on transient stability of virtual synchronous generators under grid voltage sag[J]．IEEE Transactions on Industrial Electronics，2022，69(5)：4754-4764． doi:10.1109/tie.2021.3082055
[9]	CHEN M， ZHOU D， BLAABJERG F ．Enhanced transient angle stability control of grid-forming converter based on virtual synchronous generator[J]．IEEE Transactions on Industrial Electronics，2022，69(9)：9133-9144． doi:10.1109/tie.2021.3114723
[10]	XU H P， ZHANG D Y， CHEN L ．Coordination of resistive SFCL and additional power controller for transient stability enhancement of virtual synchronous generator[J]．IEEE Transactions on Applied Superconductivity，2021，31(8)：1-6． doi:10.1109/tasc.2021.3091093
[11]	SUN K， YAO W， WEN J Y ．A two-stage simultaneous control scheme for the transient angle stability of VSG considering current limitation and voltage support[J]．IEEE Transactions on Power Systems，2022，37(3)：2137-2150． doi:10.1109/tpwrs.2021.3121474
[12]	潘子迅，杨晓峰，赵锐，等．不平衡电网下虚拟同步机的多模式协调策略[J]．电工技术学报，2023，38(16)：4274-4285．
	PAN Z X， YANG X F， ZHAO R，et al ．Multi-mode coordination control of virtual synchronous generator under unbalanced power grid[J]．Transactions of China Electrotechnical Society，2023，38(16)：4274-4285．
[13]	孙健浩，初壮．考虑碳交易和无功补偿的分布式电源优化配置[J]．发电技术，2024，45(1)：142-150．
	SUN J H， CHU Z ．Optimal configuration of distributed generation considering carbon trading and reactive power compensation[J]．Power Generation Technology，2024，45(1)：142-150．
[14]	SHI K， YE H H， SONG W T ．Virtual inertia control strategy in microgrid based on virtual synchronous generator technology[J]．IEEE Access，2018，6：27949-27957． doi:10.1109/access.2018.2839737
[15]	ZHAO F， SHUAI Z K， SHEN C，et al ．Comparison of transient angle stability between different virtual synchronous generators[C]//2019 IEEE 3rd Conference on Energy Internet and Energy System Integration (EI2)．Changsha，China：IEEE，2019：2529-2533． doi:10.1109/ei247390.2019.9062257
[16]	王继磊，张兴，朱乔华，等．虚拟同步发电机暂态稳定性分析与控制策略[J]．电机与控制学报，2022，26(12)：28-37．
	WANG J L， ZHANG X， ZHU Q H，et al ．Transient stability analysis and control strategy of virtual synchronous generator[J]．Electric Machines and Control，2022，26(12)：28-37．
[17]	陈宇杰，王淳，王青，等．基于角频率偏差补偿的VSG有功控制[J]．电网技术，2019，43(9)：3432-3439．
	CHEN Y J， WANG C， WANG Q，et al ．A VSG active power control based on angular frequency deviation compensation[J]．Power System Technology，2019，43(9)：3432-3439．
[18]	SONI N， DOOLLA S， CHANDORKAR M C ．Improvement of transient response in microgrids using virtual inertia[J]．IEEE Transactions on Power Delivery，2013，28(3)：1830-1838． doi:10.1109/tpwrd.2013.2264738
[19]	李清辉，葛平娟，肖凡，等．基于功角与电流灵活调控的VSG故障穿越方法研究[J]．中国电机工程学报，2020，40(7)：2071-2080．
	LI Q H， GE P J， XIAO F，et al ．Study on fault ride-through method of VSG based on power angle and current flexible regulation[J]．Proceedings of the CSEE，2020，40(7)：2071-2080．
[20]	张余余，赵晋斌，李芬，等．基于功角动态补偿的VSG故障穿越方法研究[J]．电网技术，2021，45(9)：3667-3673．
	ZHANG Y Y， ZHAO J B， LI F，et al ．VSG fault crossing method based on dynamic compensation of power angle[J]．Power System Technology，2021，45(9)：3667-3673．