电压源型电能质量控制技术研究

设计了应用于配电网的电压源型电能质量控制系统,该系统主要包括整流器、三相逆变器、控制器、电压电流检测电路等.研究了提高用户电压质量的电压无功控制规律,设计了抑制电压波动和闪变的控制系统,并分析了控制系统的稳定性以及控制作用与网侧阻抗的关系.给出了谐波电压模拟检测电路并对其幅频特性和相频特性进行了仿真计算.通过电能质量控制系统与电网间同步运行试验和谐波电压抑制试验,实现了逆变器与电网的同步运行控制以及负载谐波抑制控制.     

多路数字绝缘电阻测试仪的设计

为了准确可靠地实现电气设备绝缘电阻多路巡回检测,提出了基于PC/104总线的数字绝缘电阻测试仪的结构和系统硬件、软件设计方案;系统选择反激式单片开关电源设计方案,产生250V直流测试电压;采用光电微电子继电器开关电路,检测24路绝缘电阻;采用线性隔离放大电路,提高系统安全性;实现了多路绝缘电阻的巡回检测和自动量程转换功能,绝缘故障时准确报警;实验结果表明,该仪表满足测量多路绝缘电阻的要求,缩短了测试时间,提高了测试效率,运行性能良好.     

UPS逆变器的渐近收敛无差拍控制

传统无差拍控制应用于UPS逆变器,存在对系统参数变化的鲁棒性问题.本文提出了一种新的控制方案-渐近收敛无差拍控制.该方案与传统无差拍控制的区别是,不是将正弦信号作为参考电压,而是采用当前的输出电压和正弦信号的加权平均作为下一控制周期的目标量.基于DSP搭建了1kVA/700W的实验样机.理论分析和实验结果表明,渐近收敛无差拍控制有良好的稳态性能和快速的动态响应,对系统参数的变化有较好的鲁棒性.     

A Robust Deadbeat Control Method for UPS Inverters

The traditional deadbeat control for UPS inverters has a robustness problem. The parametric imprecision can greatly harm the stability of the system, which restricts the application. A novel robust deadbeat control method is proposed in this paper to deal with the problem. In the proposed control method, a proportional element is added to the traditional deadbeat control in order to improve the robustness to parametric imprecision. To eliminate the error between output voltage and voltage reference caused by environmental noise and parametric deviation, a model reference adaptive regulator is also added to the control method. A 1kVA prototype is built based on DSP. Theoretical analysis and experimental results show that the robustness for parametric variation of the proposed method is much better than the traditional deadbeat control. The system can remain stable even when the systemic parameters have a large deviation from calculating parameters. The system has small static error and fast dynamic response with the new control method. This method is easy to realize in DSP and is suitable for full digital realization of UPS.