摘要
提出一种应用于单相并网逆变器的可降低开关损耗的模型预测控制方法。该方法基于单相逆变器的离散状态模型,首先加入参考电流方向的判断,对开关状态进行初步筛选并且闭锁部分器件的状态,设置电流跟踪差为指标函数,将筛选出的开关状态代入指标函数进行寻优,选出可使指标函数最小的开关状态;其次引入降损指标函数,判断当前时刻的控制误差,若控制误差在限定范围,保持前一时刻开关状态输出,否则根据当前时刻指标函数最小值更新开关状态,从而大幅降低系统开关频率。该控制方法原理简单、数字化控制易于实现,与传统的控制方式相比,其不用整定PI参数,且系统具有较强鲁棒性。仿真结果表明控制器对并网电流跟踪性能良好,大幅降低了开关频率。
A method based on the model predictive control is proposed to decrease the switching loss of single-phase grid-connected inverter. It detects the current direction based on the discrete state model of the inverter to select the switching state preliminarily and to block the states of some devices,takes the tracking current difference as the index function and substitutes the selected switching state into the index function to search the optimal switching state resulting in the minimum index function. A loss reduction function is then introduced to evaluate the current control error,if the error does not exceed the limit,the switching state output remains,otherwise changes the switching state output according to the present minimum of index function to significantly reduce the system switching frequency. The proposed control method is simple in principle and easy to implement the digital control. Compared with traditional control methods,the system is more robust and no PI parameters are needed. Simulative results show that,the controller tracks the grid-connection current well and the switching frequency is greatly reduced.
出处
《电力自动化设备》
EI
CSCD
北大核心
2015年第8期84-89,共6页
Electric Power Automation Equipment
基金
国家自然科学基金资助项目(51207086)
上海市教育委员会科研创新项目(14YZ126)
上海绿色能源并网工程技术研究中心资助项目(13DZ2251900)~~
关键词
模型预测控制
开关状态
跟踪控制
开关频率
优化
逆变器
model predictive control
switching state
tracking control
switching frequency
optimization
electric inverters
