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

为了提高具有双层电容增强再生能力的升压器的PWM逆变器的性能，在以前的研究中，我们提出了具有双层电容增强再生能力的升压器的PWM逆变器。在该电路中，电容器与电池并联。因此，电路需要大量的电容器单元。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。在拓扑1中，采用了蓄电池和双层电容同时使用升压变换器和只使用双层电容的降压变换器的结构。所有的再生功率被吸收的双层电容器。然而，该拓扑不能控制双层电容器的端电压，为了解决该问题，拓扑2使用两个双向升压器来控制来自双层电容器的功率或去往双层电容器的功率。其中一个升压器用于电池和双层电容器，以控制PWM逆变器的直流链电压。另一个仅用于双层电容器，以控制从双层电容器流出和流入双层电容器的电流。提出了系统功率流控制策略和蓄电池电流间接控制策略，讨论了升压器电流与蓄电池电压与双层电容电压比的关系。这些结果对拓扑2的系统设计是有用的。最后，从建议和以前的拓扑结构的结果进行了比较，它表明，拓扑2具有最有利的电容器的数量和控制能力。

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.