Vienna rectifiers are widely used as front-end rectifiers in many applications because of their high efficiency and high power density. However, this topology has a problem that its current is always distorted near zero-crossing points, especially when the converter-side current ripples are large. This paper reveals and models the zero-crossing current distortion phenomenon, which is caused by non-shared vectors of adjacent sectors when the sector detection error occurs. Near the zero-crossing points, the inevitable sector detection errors will occur due to the presence of the switching current ripples and other factors such as the control delay. The errors can be divided into two types, namely the lag error and the lead error. The effects of the two types of errors are equivalently modeled in the dq frame in this paper. When the detection error occurs, it is equivalent to applying additional interference terms to the control output. Based on the equivalent error model, the paper proposes two compensation methods to eliminate the zero-crossing effect caused by the sector error. The proposed methods are easy-to-implement and effective. Finally, simulation and experimental results validate the theoretical analysis.

An improved scheme of a dual‐switch forward converter is proposed in this paper. Compared with the original converter, the new one can provide higher resetting voltage during the hold‐up time interval under the action of an additional reset capacitor. Namely, it allows the converter's duty cycle to be larger than 50%. As a result, the proposed method can transfer more energy stored in the bulk capacitor to the load side during the hold‐up interval. Therefore, a smaller bulk capacitor can be used for the converter's hold‐up time requirement. Since the additional reset capacitor acts only as a compensation, it would not affect other performance of the converter. The additional circuit can be applied for the dual‐switch forward converter when small‐volume and high power density are required. The working principle and the performance of the converter are analysed, and the relevant theory formulas are deduced. Then the parameters of key components are given. Finally, the theoretical analysis is validated through a 200 W experimental prototype.

The double-section phenomenon is inherent to the sequential switching shunt regulator (S3R), which increases the bus ripple, affects the poststage filter design, generates electromagnetic interference, and reduces the system reliability. In this article, an in-depth study of the S3R reveals that the double-section phenomenon is caused by a combination of hysteresis loop overlap, sampling integration delay, and parasitic capacitance of the solar panel. To suppress the influence of the double-section phenomenon, according to the working characteristics of S3R, an improved controller is proposed: first, replace the ladder-shaped comparators with the ladder-shaped subtracters and then use fixed frequency control to fix the sampling ripple frequency; subsequently, the specific frequency of the sampling ripple is compensated to reduce the phase shift, thus reducing the delay of the sampling signal, and finally, the S3R’s double-section phenomenon is suppressed. The controller’s specific structure and parameter design procedure are also given in this article. Finally, the correctness and feasibility of the proposed method are proved by building an experimental prototype.

The lithium-ion battery equalization system is a critical component in Low-Earth Orbit (LEO) satellite power supply systems, ensuring the consistency of battery cells, maximizing the utilization of battery pack capacity, and enhancing battery reliability and cycle life. In DC bus satellite power systems, passive equalization technology is widely adopted due to its simple structure and ease of control. However, passive equalization suffers from drawbacks such as complex thermal design and limited operation primarily during battery charging. These limitations can lead to inconsistent control over the depth of discharge of individual battery cells, ultimately affecting the overall lifespan of the battery pack. In contrast, active equalization technology offers higher efficiency, faster equalization speeds, and the ability to utilize digital control methods, making it the mainstream direction for the development of lithium-ion battery equalization technology. Nevertheless, active equalization often requires a large number of switches and energy storage components, involves complex control algorithms, and faces challenges such as large size and reduced reliability. Most existing active equalization techniques are not directly applicable to DC bus satellite power systems. In this study, based on the operational characteristics of LEO satellite power storage batteries, an active–passive hybrid equalization topology utilizing a switching matrix is proposed. This topology combines the advantages of a simple structure, ease of control, and high reliability. Its feasibility has been validated through experimental results.

This paper investigates the leader-following consensus problem for second-order nonlinear multi-UAV systems under both fixed and Markovian switching topologies. A distributed event-triggered control protocol is proposed, which incorporates a unified triggering function that simultaneously handles intra-cluster and inter-cluster state errors. For fixed topology, sufficient conditions are derived to ensure practical fixed-time consensus. For Markovian switching topologies, a rigorous stability-guaranteeing framework is established using Multiple Lyapunov Functions and Average Dwell Time theory, which formally ensures asymptotic consensus under admissible switching signals. The absence of Zeno behavior is rigorously proved by deriving a positive lower bound on inter-event times. Comparative numerical simulations demonstrate that the proposed strategy achieves faster convergence and significantly reduces communication burden compared to conventional methods, validating its effectiveness and superiority in dynamic multi-cluster environments.

This letter proposes an interleaved hybrid control for parallel three‐level (TL) LLC converters in battery charging applications. The duty cycle and the switching frequency are used to adjust the voltage gain; the phase shift control is adopted to realize voltage sharing of the divided capacitors. A virtual equivalent frequency‐gain control is adopted to coordinate multiple control variables. And the current ripples are reduced for the interleaved structure. Based on the performance analysis, an upper optimizer is proposed to update the upper limit frequency and interleaving arrangement in real time. Accordingly, it achieves a wide range of output voltage, and it further improves the system efficiency under light load and low output voltage conditions. A prototype is presented to verify the effectiveness of the proposed method.