A Single-Phase Single-Stage Current Source Inverter With Buck-Boost Capability and Reduced Inductor

For the conventional single-phase current source inverter (CSI), a large inductor is needed to stabilize the input current, which increases system volume, cost, and losses. In this article, a single-phase single-stage CSI with its operation principle is proposed. Different from conventional CSIs where only voltage-boost operation is supported, the input dc-link voltage of the proposed CSI can be higher than the peak value of output voltage (buck mode), and it can also be lower than the peak value of output voltage (boost mode). So, it is very suitable for occasions with a wide input voltage range. Moreover, the input inductor current can be balanced within per switching cycle using the proposed operation strategy. As a result, the input inductor and output filter capacitor are decreased. First, the derivation and operating modes of the CSI are given in detail. Then, the design guidelines of the components are presented, and a comparison with some existing CSIs has been made. A 1 kW prototype is also built and tested in the laboratory, the experimental results are presented to verify the effectiveness of the proposed CSI and control strategy.