DING Yong,MAO Meiqin,ZHANG Jintao.Oscillator-resembled Phase Locked Loop-less Unified Power and Voltage Controller for Grid-connected Inverter[J].Automation of Electric Power Systems,2025,49(22):35-43.
DING Yong,MAO Meiqin,ZHANG Jintao.Oscillator-resembled Phase Locked Loop-less Unified Power and Voltage Controller for Grid-connected Inverter[J].Automation of Electric Power Systems,2025,49(22):35-43. DOI: 10.7500/AEPS20250617001.
Oscillator-resembled Phase Locked Loop-less Unified Power and Voltage Controller for Grid-connected Inverter
The establishment of a new power system requires grid-connected inverters to be able to flexibly adapt to complex power grid conditions. The use of traditional dual-mode grid-following/grid-forming control for grid-connected inverters has problems of mode switching and complex control
while there exist problems of multiple control parameters and complicated design when virtual oscillator control is adopted. To this end
by referring to the oscillating voltage self-formation principle of nonlinear oscillators simulated through virtual oscillator control
an oscillator-resembled phase locked loop-less unified power and voltage controller (OR-PLL-less UPVC) for grid-connected inverters is proposed. The OR-PLL-less UPVC consists of power control module
voltage self-formation module
and voltage magnitude regulation module. First
the structure and operation principle of each module in OR-PLL-less UPVC are introduced
and the control law of the inverter output voltage is analyzed. Then
the state-space model of the system is established to analyze its small-signal stability. Finally
through simulation and real-time controller hardware-in-loop experiments
it is verified that the proposed OR-PLL-less UPVC can autonomously adjust the inverter port voltage under variations in parameters such as grid-side line impedance
power grid voltage/frequency
and track the power dispatching instructions
achieving the unified grid-following/grid-forming control under complex operating conditions.
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DING Yong
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Related Institution
North China Branch of State Grid Corporation of China
State Key Laboratory of Power System Operation and Control (Tsinghua University)
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