Zhicheng Zhou

Bio: Zhicheng Zhou is an academic researcher from China Academy of Space Technology. The author has contributed to research in topics: Inductor & Switched-mode power supply. The author has an hindex of 4, co-authored 5 publications receiving 84 citations.

A Novel Phase-Shift Dual Full-Bridge Converter With Full Soft-Switching Range and Wide Conversion Range

Abstract: This paper proposes a novel phase-shift dual full-bridge converter with shared leading leg and dual outputs in series. Full soft-switching range of the active switches can be achieved based on the parallel full-bridge configuration of the converter, and the dual outputs of the proposed converter are connected in series. The output voltage can be regulated by primary-side phase-shift and secondary-side phase–shift dual-mode control scheme, and a wide conversion range can be achieved. Furthermore, the circulating current in the primary-side full-bridge circuits can be extinguished. Therefore, the proposed converter would be useful for constant peak power and wide output voltage range applications. Steady-state operation and relevant analysis results of the proposed converter are presented and verified on a 1.5-kW hardware prototype. The experimental results show that the proposed converter can achieve a peak efficiency of 95.3%.

Three-Port DC/DC Converter With All Ports Current Ripple Cancellation Using Integrated Magnetic Technique

Abstract: This paper presents a novel integrated magnetic three-port converter (IMTPC) with high power density and all three ports’ current ripple cancellation. The proposed IMTPC can interface one PV port, one bidirectional battery port, and one load port of the PV-battery dc power system. Only two high power magnetic devices are needed in an IMTPC for realizing power conversion, ripple cancellation, and switch driver simultaneously. Three extra capacitors were added to achieve three ports’ current ripple cancellation. Therefore, the port of the IMTPC will always in continuous-conduction mode with “zero current ripple,” thus, size of passive filter can be reduced and accuracy of maximum power point tracking can be improved. Meanwhile, simple driving of the high-side switch can be realized by integrated magnetic winding, which is responsible for MOSFET driver's voltage level shift. The using of the integrated magnetic technique not only performs aforementioned advantages but also shows great potential for reducing the weight and volume of the dc–dc converter. Finally, experimental verifications are given to illustrate the feasibility and effectiveness of the proposed topology and control method.

Linear Regulator Design Considerations of the Serial Linear-Assisted Switching Converter Used as Envelope Amplifier

Abstract: Envelope elimination and restoration technique and envelope tracking technique are proposed to enhance efficiency of radio frequency power amplifier (RFPA), and both of them take envelope amplifier (EA) as a high slew-rate variable voltage source. Serial linear-assisted switching converter, one of the solutions of EA, has benefits in high tracking bandwidth, high tracking accuracy, and relatively low switching losses. Among those many types of linear-assisted switching converter, the design of a linear regulator is rarely mentioned. This paper proposes a new design of linear regulator to supply a higher voltage and maintain high tracking bandwidth by dividing a linear regulator into four different parts. Beyond that, an input filter is recommended to increase the power supply rejection ratio (PSRR) of a linear regulator in high frequency, which is able to reduce the glitch caused by multilevel voltage power supply. An EA prototype is composed of the proposed linear regulator, the PSRR improvement filter, and the multilevel voltage power supply. To align signals, circular convolution is suggested as a modified algorithm. Experiments show that this prototype has a maximum output of 40 V, a tracking bandwidth of about 2 MHz for a full-range sinusoidal signal, and a tracking ability for OFDM envelope signal with a subcarrier up to 5 MHz.

Active Voltage Sharing Module for Input-Series Connected Modular DC/DC Converters

Abstract: Since both the input-series–output-series system and the input-series–output-parallel system have a circuit configuration in which the input sides are in series, it is very suitable for applications with high input voltages. This article proposes a simple active voltage sharing module (AVSM) that allows two closed-loop dc/dc converters to be combined directly into an input-series system as power devices to meet various voltage requirements. An AVSM, consisting of one coupled inductor and two metal–oxide–semiconductor field-effect transistors, is connected on the input side of the two submodules. By adopting a control method with fixed frequency and duty cycle, accurate input voltage sharing can be achieved, enabling voltage isolation sampling of the submodules and the voltage sharing regulators of the system to be eliminated, thus greatly simplifying the design process of the input-series system. This article introduces the AVSM working principle and discusses the stability of the proposed input-series system. It then describes a simulation performed to verify the theoretical analysis results and addresses the influences of the AVSM parameters on the system performance. Finally, the use of a prototype to test the steady-state and dynamic performances of the proposed scheme is discussed.

A Building Block Method for Input-Series-Connected DC/DC Converters

Abstract: DC/DC converters are connected in series at the input so that low power devices can be used in high-voltage conversion applications. This article proposes a building block method for constructing an input-series-connected dc/dc converter, which combines voltage sharing modules (VSM) with voltage source modules or current source modules. A VSM consists of two MOSFETs, an inductor, and an open-loop driver. The input voltage sharing between the individual modules is achieved by connecting one VSM to the inputs of the two power modules. The proposed method makes the standardized functional modules can be combined together like building blocks, which greatly simplifies the converter complexity and shortens the system development cycle without sacrificing the high dynamic response performance and excellent sharing effect. This article first analyzes the working principle of the converter. Second, the stability constraints of the proposed method are revealed, and the effects of various parameters on the performance are discussed. Furthermore, the theoretical analysis results are verified by simulation. Finally, taking the voltage source module as an example, a prototype is built to test its steady-state and dynamic performance.

Energy storage system: Current studies on batteries and power condition system

Abstract: To maximize the introduction of renewable energy, introducing grid energy storage systems are essential. Electrochemical energy storage system, i.e., battery system, exhibits high potential for grid energy storage application. A battery energy storage system is comprised of a battery module and a power conversion module. This paper starts by reviewing several potential battery systems, as well as an advanced aluminum-ion battery that currently has promising prospects in the electrochemical energy storage system. The characteristics of the batteries are reviewed and compared, including the materials, electrochemistry, performance and costs. The application prospect of the batteries is discussed. The paper summarizes the features of current and future grid energy storage battery, lists the advantages and disadvantages of different types of batteries, and points out that the performance and capacity of large-scale battery energy storage system depend on battery and power condition system (PCS). The power conversion system determines the operational condition of the entire energy storage system. The new generation wide bandgap semiconductor for power electronic technology is discussed from the perspective of performance, topology, model and non-linearity and is compared to the traditional silicon-based semiconductor. Finally, the application prospect of the new generation semiconductor technology in the energy storage system is indicated. This paper concludes the application status of the energy storage system in the renewable energy power generation and indicates the critical problems that need to be addressed during the construction and operation of the storage system.

Switched Capacitor Converter Based Multiport Converter Integrating Bidirectional PWM and Series-Resonant Converters for Standalone Photovoltaic Systems

Abstract: Photovoltaic (PV) systems containing a rechargeable battery as an energy buffer require multiple dc–dc converters for PV panel control and battery regulation, and hence, they are prone to be complex and costly. To simplify the system by reducing the number of converters, this paper proposes the nonisolated switched capacitor converter (SCC)-based multiport converter (SC-MPC) for standalone PV systems. The proposed SC-MPC can be derived by integrating a bidirectional pulsewidth modulation (PWM) converter, series-resonant converter (SRC), and an SCC with sharing switches. PWM and pulse frequency modulation (PFM) controls are employed for the PWM converter and SRC, respectively, to regulate either a battery voltage, output voltage, or input power from a PV panel, depending on power balance among the input, battery, and load. The 150-W prototype was built for an experimental verification, and the results demonstrated the output voltage could be regulated independently on the battery voltage or input port of PV panels.

Dual-Transformer-Based DAB Converter With Wide ZVS Range for Wide Voltage Conversion Gain Application

Abstract: A control strategy is proposed for the dual-transformer-based dual-active-bridge converter to achieve wide zero-voltage switching (ZVS) range for wide voltage conversion gain range application The phase-shift control is adopted for the dual-transformer-based converter with minimum power switches employing half bridge output, and a control law is proposed to achieve wide ZVS range and reduce the current-related loss With the proposed method, four switches of the converter can achieve full range of ZVS The other two switches can achieve full-range ZVS under positive power flow, while a slightly reduced ZVS region under reverse power flow Unlike the methods employing three control degrees of freedom, the proposed method only utilizes two decoupled control variables, making the controller easy to be implemented, more reliable, and independent of the converter parameters In addition, the design of turns ratios for the two transformers is also optimized based on the control law and loss analysis The effectiveness of the converter with the proposed control is verified by experimental results from a 1-kW prototype

An Overview of High-Conversion High-Voltage DC–DC Converters for Electrified Aviation Power Distribution System

Abstract: This article presents the state-of-the-art review of high-conversion high-voltage (HCHV) dc–dc converters for a modern aerial vehicle’s power distribution system. Higher dc bus voltages have become a trend in recent aerial vehicle development because of the potential reduction in size and weight of the rest of the power system and an increase in power density. Some front-end dc energy sources, such as fuel cells, batteries, and supercapacitors, may level at a low voltage and require HCHV dc–dc converters to integrate with the high-voltage dc bus. On the other hand, high-conversion step-down converters are required between the dc bus and various low-voltage electronic loads. A detailed review of HCHV dc–dc converters for an aviation power distribution system is limited in the literature. This article presents two main architectures of such converters. Architecture-I employs individual two-port dc–dc converters to link each source to the dc bus, and Architecture-II uses a single multiport converter (MPC) to connect all the sources to the dc bus. Architecture-I categorizes the two-port dc–dc converter topologies into unidirectional and bidirectional converters, followed by further classifications based on isolation and control schemes. Multiport dc–dc converters for Architecture-II are categorized based on port numbers and then source connection methods. This review investigates multiple topologies within each category or classification, highlighting selected circuit diagrams and their features and shortcomings. This article presents several insightful comparisons, among various bidirectional converters for Architecture-I, and MPCs for Architecture-II, for a designer to choose a proper converter. In terms of converter characteristics, this article focuses on dc voltage gain, power density, efficiency, and reliability, as these qualities are of utmost importance in an aviation application.