Development of High Performance Power Converters for New Energy System Utility Interface

在2001年，即该项目的最后一年，为了加速光伏系统连接到交流系统线路的扩散，对以下几点进行了研究，并取得了一些优异的结果：（1）通过简化系统配置来降低成本已经开发了两种新的无功率传感器MPPT（最大功率点跟踪）控制方案，并向IEEJ交易报告。(2)本文介绍了一种基于空间矢量调制（SVM）技术的新型软开关变换器及其控制方案，并在国际会议上作了报告。(i)基于功率均衡的MPPT控制新方案：不需要光伏阵列瞬时功率信息，即可实现自身最大化。交流系统侧电流小回路的内部控制信号al代替实际功率。阐明了确保稳定运行和快速响应的设计准则。(ii)新的基于极限环现象的MPPT控制方案：它不仅删除了功率传感器，但爬山最大化算法的最大功率。给出了保证鲁棒极限环产生的系统设计准则。(iii)新的软开关拓扑及其控制方案：提出了三相输出的高频联动系统接口变换器，并提出了一种新的SVM技术，该技术考虑了软开关操作对换流的限制。仿真和实验结果都证明了上述思想的正确性.

In 2001, the last year for this project, the following points have been investigated in order to accelerate the diffusion of PV systems connected to the ac system lines, and some excellent results have been obtained ;(1) Cost reduction by simplifying the system configurationTwo kinds of new power sensor-less MPPT(maximum power point tracking) control schemes have been developed, and reported to the IEEJ transactions.(2) Additional value with multifunctionA new soft switching converter and its control scheme based on SVM(space vector modulation) technique have been developed, and reported in an international conference.The main ideas of new proposals are as follows.(i) New MPPT control scheme based on power equilibrium : It needs no information of instantaneous power generated by PV array to maximize itself. The interior control sign al for current minor loop on ac system side is utilized in place of the actual power. The design criteria to ensure a stable operation and fast response have been clarified.(ii) New MPPT control scheme based on limit cycle phenomena : It removed not only power sensors, but also mountain climbing maximizing algorithm for maximizing the power. The system design criteria to guarantee the robust limit cycle generation have been given.(iii) New soft switching topology and its control scheme : High frequency linked system interface converter with three-phase output was proposed, and new SVM technique in witch the restrictions in commutation due to the soft switching operation being taken into account has been proposed. Those all ideas have been proven by both simulation and experimental results.