Improvement of Performance of PWM Inverter with Voltage Booster with Regenerating Capability Augmented by Double-Layer Capacitor

在前人的研究中，我们提出了用双电层电容增强再生能力的升压型PWM逆变器。在该电路中，电容器并联到电池上。因此，电路需要大量的电容单元。在本研究中，我们提出了两种电路拓扑(电路拓扑1和电路拓扑2)来减少电容单元的数量。在这些拓扑中，电容器串联连接到电池。在拓扑1中，使用了用于电池和双层电容器的升压转换器和用于仅用于双层电容器的降压转换器。所有的再生能量都被双层电容器吸收。然而，这种拓扑结构不能控制双层电容器的端电压，为了解决这个问题，拓扑2使用了两个双向升压器来控制来自或到双层电容器的功率。其中一个升压器同时用作蓄电池和双层电容，用于控制PWM逆变器的直流侧电压。另一种只用于双层电容器，以控制进出双层电容器的电流。提出了系统的潮流控制策略和蓄电池电流间接控制策略，并讨论了升压电流与双层电容器蓄电池电压比之间的关系。这些结果对拓扑2的系统设计是有用的。最后，将所提出的拓扑和以前的拓扑的结果进行了比较，结果表明，拓扑2在电容数量和控制能力方面具有最大的优势。

Performance of PWM inverter with voltage boosters which had regenerating capability augmented by double-layer capacitor was improved.In previous research, we proposed PWM inverter with voltage booster which had regenerating capability augmented by double-layer capacitor. In this circuit, the capacitor was connected to battery in parallel. So, the circuit needed a large number of capacitor cells. As the result, the topology increased cost, volume and weight of the system.In this research, we proposed two circuit topologies (circuit topology 1 and circuit topology 2) to reduce the number of capacitor cells. The capacitor was connected to the battery in series in these topologies.For the topology 1, a step-up converter for both of battery and double-layer capacitor and a step-down converter for only double-layer capacitor were used. All regenerative power was absorbed by the double-layer capacitor. However, this topology was not able to control the terminal voltage of the double-layer capacitor.To solve the problem, the topology 2 used two bidirectional voltage boosters to control the power from or to the double-layer capacitor. One of the boosters was used for both of the battery and double-layer capacitor to control the dc link voltage of PWM inverter. The other was used for only the double-layer capacitor to control the current flowing from and to the double-layer capacitor. A strategy to control the power flow of the system and a strategy of battery current indirect control were proposed.The relation between the currents of voltage boosters and the ratio of battery voltage to voltage of double-layer capacitors was also discussed. These results are useful to design the system for topology 2. Finally, the results from proposed and previous topologies were compared and it was shown that the topology 2 had most advantageous in terms of the number of capacitors and control capability.