摘要: |
为了解决光伏并网发电系统漏电流问题,针对三相电压源逆变器,提出一种新型有限集模型预测控制减少逆变器共模电压的方法,即对光伏并网发电系统进行建模分析。研究发现只有非零矢量用于减少共模电压,故将非零矢量带入价值函数得到最优的矢量并在下一个周期使用。该新型有限集模型预测控制将共模电压限制于±1/6Vdc,可以减少光伏发电系统中漏电流,保证人身安全。和传统PI控制方法相比,模型预测控制可以提高电流跟踪的速度和精度。实验结果表明,该新型有限集模型预测控制能够减少共模电压和控制负载电流,具有快速的动态响应。 |
关键词: 三相逆变器;模型预测控制;共模电压;漏电流 动态响应 |
DOI:10.7667/PSPC151886 |
投稿时间:2015-10-26修订日期:2015-12-17 |
基金项目: |
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Finite set control model predictive control method to reduce common-mode leakage for three-phase voltage source inverter |
CHEN Suhua |
(College of Electrical Information Engineering, Xuchang University, Xuchang 461000, China) |
Abstract: |
In order to resolve the leakage current problem, this paper proposes a new finite-set model predictive control to reduce common-mode voltage of three-phase inverter. The model of photovoltaic (PV) grid power generation systems is analyzed. The study finds that only the nonzero vector is used to reduce the common mode voltage. Therefore, the nonzero vector is brought into the value function and the optimal vector is got to be used in the next cycle. The common-mode voltage can be limited to ±1/6Vdc by using the proposed finite-set model predictive control. This method can suppress the leakage current and guarantee the safety of human life. Compared with traditional PI method, it can improve the current tracking speed and precision. Therefore, the proposed model predictive control can reduce the common mode voltage and load current and has fast dynamic response. |
Key words: three phase inverter model predictive control common mode voltage leakage current dynamic response |