Minrui Leng

• Sichuan University

High-gain dc-dc converters are an important link for connecting low-voltage renewable energy sources, such as photovoltaics, to the high-voltage dc bus. This paper presents a non-isolated ultra-high voltage gain converter based on a three-winding coupled inductor for distributed renewable energy applications. The input inductor and clamping capacit...

The linear-motor type magnetic flux pump serves as a wireless power source intended for charging second-generation (2G) high-temperature superconducting (HTS) double-pancake coils (DPC). This study is grounded in the utilization of magnetic flux pump apparatus, in conjunction with the theoretical framework of macroscopic magnetic coupling effects (...

This study investigates the feasibility of utilizing the line loss power factor to assess the reactive, unbalanced, and harmonic line losses in low-voltage distribution networks and explores the method of calculating decoupled line loss values based on this factor. To achieve this objective, we establish preliminary definitions of single-phase and...

Conventional buck power factor correction (PFC) converter has the disadvantage of high harmonic currents due to the dead zone of input current. An improved method, critical-continuous mode control buck-flyback converter has not completely eliminated the impact of dead zone of buck unit on the input current. In this paper, a single-stage integrated...

In this paper, primary LCC compensation topology and their variants are firstly investigated to adapt sub-harmonic control so that the wireless power transfer system can achieve the advantageous of soft switching, inherent open-circuit protection, high design freedom and high efficiency, simultaneously. Extensive comparisons are conducted among the...

Sub-harmonic control (SHC) is an excellent method for wireless charging system because it is easy to achieve full-load range soft switching and unity power factor. However, in existing works, SHC is only applied to the system with primary series compensation topology (PSCT), which has the drawbacks of low degrees of design freedom, high sensitivity...

Due to increased efforts on digitizing the modern power electronic systems and microgrids, their operational reliability and stability are prone to the risk of cyber attacks. In this paper, we inspect the overlooked stability issues caused by cyber-attacks, and present an overall design insight for stabilization of microgrids under cyber attacks. F...

Bipolarity in dc microgrids is desirable as it enhances the system's reliability and efficiency. However, the stability assessment for bipolar dc microgrid is challenging due to the integration of three-wire dc distribution line and numerous connected power converters, which is different from the stability analysis of conventional unipolar dc micro...

This paper develops a cost-effective and efficient wireless charger with multiple outputs based on newly proposed H3 bridge inverter, which has the benefits of reduced switch requirements and independent regulation capability. The output power of each channel is regulated by asymmetric duty cycle control. With the help of auxiliary LC branch, soft...

Inductive power transfer (IPT) technology becomes highly attractive option for wireless battery charging applications. To fulfill the charge profile of battery packs, wide output voltage regulation is always necessary. In this paper, an improved LCC-S compensated IPT system utilizing variable frequency switched capacitor control is put forward. Com...

Model predictive control (MPC) is one of the promising candidates for power converters with improved stability and faster response. Overshoot, a crucial transient precursor, is a custom design requirement based on the converters' applications having variant time-domain specifications that are subject to their safety and reliability. Apart from the...

Microgrids relying on cooperative control are supported by communications, which are highly vulnerable to cyberattacks. A significant amount of research is already carried out on the detection and mitigation of cyberattacks to secure the operation of dc microgrids. Although cyberattacks are fully capable of causing cascaded converter outages leadin...

A multi-port converter with bipolar outputs to integrate renewable energy and energy storage into the bipolar dc bus is the desirable solution due to its high reliability and efficiency. A novel symmetric bipolar outputs full-bridge four-port converter based on phase-shift modulated buck-boost voltage balancer is proposed in this paper. The interle...

Inductive power transfer (IPT) systems with multiple output voltages are potential to supply a variety of loads simultaneously. This paper proposes an IPT system with multiple semi-active rectifier cells (SARCs) connected in series at the receiver (Rx) side. These SARCs are independent of each other and their output voltages can be regulated indivi...

Multibus dc microgrids, which combine renewable energy sources, energy storage systems and loads, have voltage stability requirement, which solicits increasing research attention in practice. Potentially complex architectures of the multibus dc microgrids make it difficult to evaluate the stability using the conventional stability criteria. In this...

For a photovoltaic (PV)/battery power system consisting of PV module, energy storage system, and local load, using a three‐port converter (TPC) instead of several single‐input converters is more desirable, such as simpler circuit, higher efficiency, lower cost, and centralized control without communication circuit. In this paper, a TPC is proposed...

A current sensor based global maximum power point tracking (GMPPT) algorithm of photovoltaic (PV) system is proposed in this paper to increase the tracking speed during rapidly changing partial shading condition (PSC). For the proposed algorithm, the tracking range of duty cycle is reduced by calculating both the upper limit of duty cycle and the l...

This chapter has overviewed the application of model predictive control (MPC) methods in power electronic systems. This chapter was started with introduction of the basic definitions of the MPC as a control methodology and then with categorization of various methods belonging to the broad family of MPC, which have been applied in the general power...

Based on the current-mode switching cell (CMSC), an inductive power transfer (IPT) system with dual-output is proposed in this letter. In the proposed IPT system, two CMSCs are inversely connected in series at the Rx side. Two CMSCs operate in the positive half-cycle and in the negative half-cycle of the Rx coil current, respectively. The dual outp...

To avoid the time-consuming weighting-factor tuning work in conventional finite control set model predictive control (FCS-MPC), a sequential model predictive control (SMPC) scheme for stand-alone voltage source inverters of an islanded ac microgrid is proposed in this paper. The main idea is that two cost functions for separately minimizing the cap...

To regulate the output voltage of inductor–capacitor–capacitor-series ( LCC -S) compensated wireless power transfer (WPT) system, a hybrid control strategy of phase shift modulation (PSM) and a switch-controlled capacitor is presented in this article. In the proposed hybrid control strategy, LCC -S compensated WPT system can realize wide output...

In the standalone renewable energy system, multiport converter is more desirable than several single-input converters as it has advantages of simpler circuit, higher efficiency and lower cost. This paper proposes a novel topology synthesis method to derive integrated three-port converters with low cost and compact structure. With the proposed topol...

Interaction between individual converters in a cascaded system may affect stability. This brief investigates the effect of the load converter on the stability of the source converter in the cascaded system. On the contrary to the previous perception, a source converter in an unstable state can be stabilized after cascading with a proper load conver...

Recently, it has been reported that valley V <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> control can be applied to boost converters. However, the actual transient performance and design methodology are not clear due to insufficient knowledge about its small signal model. In this article, a...

A bipolar dc microgrid is desirable as it enhances the system reliability and efficiency. However, the conventional bipolar dc microgrid requires multiple dc-dc converters to feed the power to the load, which leads to large volume and weight and high cost. In this paper, a novel four-port converter is proposed to integrate photovoltaic (PV) module...

In a conventional photovoltaic (PV) DC microgrid system, mismatches among the PV modules due to partial shading will cause power loss. The distributed maximum power point tracking (DMPPT) can effectively solve the mismatch problem and achieve high‐efficiency power output. This study proposes a maximum power range estimation method based on the DMPP...

Average small signal model, known as a simple and powerful tool, is widely used to provide design guidance for switching converters. Due to the ignorance of high-frequency characteristics, conventional average small signal model fails to reveal dynamics of switching converters with ripple-based control. Improved small signal models for ripple-based...

To improve the load transient performance of boost converter, digital valley V <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> (DVV) control with trailing-edge modulation is proposed. After analysis of output voltage ripple of boost converter, the control law of DVV controlled boost converter i...

In order to improve the output power of PV(PhotoVoltaic) unit in the DC microgrid, the cascaded distri-buted MPPT(Maximum Power Point Tracking) architecture is used instead of the traditional centralized MPPT architecture. A DC microgrid consisting of PV units, batteries and loads is taken as the research object and the control strategy of the casc...

The discrete mapping model of current-mode controlled buck converter with constant current load, taking account of composite output capacitors (parallel connection of two different types of capacitor branches, i.e. electrolytic capacitors and ceramic capacitors), is established. Based on the model, dynamical effects of varying output capacitance an...