广义谐波电网环境电压源型并网变流器滑模变结构直接功率控制策略

Improved Sliding-Mode-Based Direct Power Control Strategy of Grid Connected Voltage Sourced Converter Under Universal Harmonic Grid

针对实际电网电压中存在实时动态变化的谐波运行环境,提出电压源型并网变流器广义谐波下的滑模变结构直接功率控制(sliding-mode-based direct power control,SMCDPC)策略;其实施是针对所有次数谐波,该控制策略不需实时精确的电网谐波次数和相位检测,具有实际工程应用价值。在以往研究成果的基础上,建立了广义畸变电网环境中的并网电压源型变流器(grid-connected voltage-sourced converters,VSC)的完整数学模型,提出3种该运行环境下的控制目标:正弦形输出电流,消除有功功率波动和无功功率波动。完成了滑模变结构直接功率控制设计。仿真结果表明,相比传统滑模变结构直接功率控制,改进的滑模变结构直接功率控制增强了电压源型并网变流器在实际电网广义电压谐波下环境中的运行能力。

Aiming at operation of grid-connected voltage-sourced converters（VSC） under universal and dynamically varied harmonic voltage conditions existing in real power grid, this paper proposes an improved sliding-mode-based direct power control（SMC-DPC）strategy under universal harmonic grid voltage. Due to tasks to all harmonics, its implementation has no need of accurate detection of concrete order and phase position of harmonics, thus with certain engineering application potentials. Based on past researches, integral mathematic model of VSC under universal harmonic circumstances is founded, three different control objectives, i.e.sinusoidal currentoutput, active and reactive power fluctuation eliminations, are devised and final improved SMC-DPC strategy under universal harmonic grid voltageis performed. Simulation results reveal that the improved strategy enhances VSC operating performance under universal grid harmonic voltage, contrasting to traditional SMC-DPC.