Cascaded multilevel converters are promising candidates for grid-connected PV systems, but low-frequency ripples may exist in a DC link. Such ripples are not just inherent; they can occur due to environmental factors, such as variations in a certain range of irradiance of the PV. To address this issue, this article proposes a clock phase-shifted (CPS) energy balance control method for grid-connected cascaded multilevel inverters for photovoltaic (PV) systems. The proposed control scheme can prevent the low-frequency ripple of the DC link propagating to the power grid. Furthermore, it is feasible in principle and no adjustment of the control parameters is needed. The simulation and experimental results verify the effectiveness and feasibility of the proposed approach.

In this paper, a novel control method is proposed based on energy balance principle in the circuit for hybrid conduction mode (HCM) boost power factor correction (PFC) rectifier. The proposed control method is universal for both the continuous conduction mode (CCM) and the discontinuous conduction mode (DCM). With this superiority, no mode transition is needed inside one mains half-cycle when operating in HCM, and thus high-quality input current can be achieved. And the proposed control method is simple to implement but rather effective. Simulation results show significant improvement compared with conventional control methods.

The cover image is based on the Rapid Communication TRPV6 variants confer susceptibility to chronic pancreatitis in the Chinese population by Wen‐Bin Zou et al., https://doi.org/10.1002/humu.24032.

The One-Cycle Controlled Boost Power Factor Correction converter has one voltage control loop, which may exhibit instability when the load is light. The instability results in a low Power Factor. To ensure that the Power Factor is high, a time delay circuit was adopted in this paper to control the instability of the converter. The architecture of the time delay circuit is described, and its transfer function is derived. The double averaging method was applied to the converter to determine the parameters in the control method. Experimental results verified the time delay control method in the converter. The power factor increased from 0.82 to 0.99 after activating the delay control circuit.