基于虚拟电阻的微电网孤岛运行控制策略
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摘要
将下垂控制应用于微电网中电压源型逆变器的并联运行,具有无需通信、即插即用的优点,增加了系统的冗余性和灵活性,但也存在系统频率偏移、输出电压跌落等问题。为此提出一种基于虚拟电阻的下垂控制策略,删除了传统三环下垂控制中的功率下垂环,使用虚拟电阻环代替原来的功率外环,通过调节虚拟电阻的阻值来使各逆变器合理分配功率。此控制策略要求各逆变器输出电压相位一致,所以使用同步脉冲来进行同步,同时也使系统频率保持在50 Hz不随负载波动。仿真和实验证明了所提控制策略的有效性。
Droop control that applied to the parallel operation of voltage source inverters in microgrid has the advantages of no need of communication,plug and play,which increases the redundancy and flexibility of the system,but there are also some problems such as system frequency offset and output voltage drop.A droop control strategy based on virtual resistance is proposed.The virtual resistance loop is used instead of the original power loop.The power sharing between different inverters is achieved by adjusting the virtual resistance.The synchronous pulse is used to synchronize the voltage phase and keep the system frequency at 50 Hz.Simulation and experiments demonstrate the effectiveness of the proposed control strategy.
Droop control that applied to the parallel operation of voltage source inverters in microgrid has the advantages of no need of communication,plug and play,which increases the redundancy and flexibility of the system,but there are also some problems such as system frequency offset and output voltage drop.A droop control strategy based on virtual resistance is proposed.The virtual resistance loop is used instead of the original power loop.The power sharing between different inverters is achieved by adjusting the virtual resistance.The synchronous pulse is used to synchronize the voltage phase and keep the system frequency at 50 Hz.Simulation and experiments demonstrate the effectiveness of the proposed control strategy.
引文
[1]王成山,肖朝霞,王守相.微网中分布式电源逆变器的多环反馈控制策略[J].电工技术学报,2009,24(2):100-107.
[2]张明锐,杜志超,王少波.微网中下垂控制策略及参数选择研究[J].电工技术学报,2014,29(2):136-144.
[3]张平,石健将,李荣贵,等.低压微网逆变器的“虚拟负阻抗”控制策略[J].中国电机工程学报,2014,34(12):1844-1852.
[4]荆龙,黄杏,吴学智.改进型微源下垂控制策略研究[J].电工技术学报,2014,29(2):145-152.
[5]周贤正,荣飞,吕志鹏,等.低压微电网采用坐标旋转的虚拟功率U/f下垂控制策略[J].电力系统自动化,2012,36(2):47-51,63.
[6]Li Y,Li Y W.Virtual Frequency-voltage Frame Control of Inverter Based Low Voltage Microgrid[A].Electrical Power&Energy Conference(EPEC)[C].2009:1-6.
[2]张明锐,杜志超,王少波.微网中下垂控制策略及参数选择研究[J].电工技术学报,2014,29(2):136-144.
[3]张平,石健将,李荣贵,等.低压微网逆变器的“虚拟负阻抗”控制策略[J].中国电机工程学报,2014,34(12):1844-1852.
[4]荆龙,黄杏,吴学智.改进型微源下垂控制策略研究[J].电工技术学报,2014,29(2):145-152.
[5]周贤正,荣飞,吕志鹏,等.低压微电网采用坐标旋转的虚拟功率U/f下垂控制策略[J].电力系统自动化,2012,36(2):47-51,63.
[6]Li Y,Li Y W.Virtual Frequency-voltage Frame Control of Inverter Based Low Voltage Microgrid[A].Electrical Power&Energy Conference(EPEC)[C].2009:1-6.