Z-source converter-based feedback type electronic load

This paper presents an ac electronic load topology based on Z-source converter. It comprises ac-dc-ac structure and the novel Z-network is also used. The new topology has some advantages over the traditional ac electronic load. On one hand, it has unique features that can boost or buck voltage without a DC-DC converter using only a modified switching pattern that adds the shoot-through zero states to the traditional SPWM, thus minimize the number of active devices. On the other hand, it can achieve PFC function, and immune to EMI noise so as to greatly increase reliability. This structure decreases the harmonic current as well as cost and volume. Hysteresis current control in the rectifier and modified SPWM control in the inverter are adopted. The ac electronic load can perform power recycle, save energy and reduce the test cost. Theoretical analysis and MATLAB simulation have been performed to describe and validate the proposed converter.