Cascaded multilevel inverter cells produce double-grid frequency ripples that require a large electrolytic capacitor bank for every cell, resulting in reduced system reliability and lifespan. This paper proposes a new generalized power-decoupling methodology that is applicable to any three-phase cascaded multilevel inverter topology. The proposed flux cancellation method is based on forcing a three-phase

A typical battery energy storage system consists of a combination of battery packs and a grid-tied power conversion system. The control algorithm of the power conversion system plays an important role when interfacing the DC energy stored in battery packs with the conventional AC grid to generate an obedient bidirectional power flow. Finite control set model predictive control is believed to be one

This paper proposes a new approach that allows the diagnosis and the ability of discernment between the frequency signatures of eccentricity faults and those of demagnetization in a permanent magnet synchronous motor (PMSM). This approach is based on the application of a very selective band-pass filter in the stator current. A judicious calculation of the parameters of this filter makes it possible

In this paper, a simplified active islanding detection method based on a power control disturbance signal for a three-phase grid-connected inverter application is presented. The disturbance and observation method is used to simplify the significant indicator, which determines the islanding condition. The control algorithm, which is used to command the observation and disturbance method, is derived

For dual-active-bridge (DAB) DC-DC converters, a variable frequency triple-phase-shift (VF-TPS) modulation strategy based on a particle swarm optimization (PSO) algorithm was proposed to solve the problem of the low efficiency of TPS modulation in larger power conditions. To facilitate the implementation of the PSO algorithm, the mathematical expressions between the transmission power or the RMS square

The conventional current and voltage control methods of AC/DC power factor correction (PFC) rectifiers have been applied using proportional-integral (PI) or proportional-resonant controls. However, these approaches do not guarantee global stability at various operating points and are sensitive to disturbances, such as parameter or load variations. In this paper, a new control method is proposed based

Due to an unfortunate oversight the acknowledgement section has been omitted.

A current-balancing strategy for a multileg interleaved DC/DC converter with a reduced number of current sensors for electric-vehicle chargers is proposed in this paper. There are imbalances between the leg currents of multileg DC/DC converters, which are caused by the difference between the leg impedances and the driver delay. Each of the leg current sensors must achieve current balancing. However

This paper proposes the independent switching technique to remove abnormal output voltage in hybrid active neutral-point clamped (ANPC) inverters. The hybrid ANPC inverter is composed by mixing silicon (Si) devices and silicon carbide (SiC) devices, unlike the conventional ANPC inverter which is generally composed of Si devices only. SiC devices provide low switching losses under a high switching frequency

In this paper, a new SVPWM switching technique, named ZSVM_1TI, has been proposed for a three-level (3L) T-type Z-source inverter (ZSI). ZSVM_1TI is based on three main modifications of the existing PWM techniques for 3L inverters. First, the existing SVPWM of a 3L ZSI has been modified to double the frequency of the null interval. After that, an improved version of the maximum boost control (MBC)

Existing PWM methods suffer from a tradeoff between zero-sequence circulating current (ZSCC) and line-current ripple, which are two major concerns of two parallel interleaved two-level (2L) voltage-source converters (VSCs). Thus, this paper introduces a novel space vector-based PWM strategy to reduce both line-current ripple and ZSCC. Given the redundancy of the vector combination of two parallel interleaved

This paper studies the characteristics of SiC inverter powertrains on common-mode (CM) EMI emission. First, a CM noise source model of an EV powertrain is built. Then, the factors of switching frequency, switching speed, and switching ringing on the CM noise source are analyzed. Finally, experiments on a conducted EMI test-bed are carried out to verify the influence of SiC inverters on conducted CM

To study the temperature distribution and change the law of the permanent magnet synchronous motors used in vehicles during extreme driving, the concept of extreme variable working condition (a running process from a low-power condition where a motor can run for a long time, to peak power and then to a low-power condition) was proposed. To calculate the temperature field, an overall simplified model

This paper analyzes and compares the typical rotating high-frequency voltage injection (RTHF) method and the typical pulsating high-frequency voltage injection (PSHF) method in terms of torque ripple and vibration. Analysis and experiment results indicate that the PSHF performs better when it comes to torque pulsation and vibration. In addition, it is more suitable for rim motors which have strict

This paper presents an enhanced compensation strategy for distributed generation (DG) systems to simultaneously achieve accurate power sharing and harmonics compensation at the point of common coupling (PCC). In the proposed control strategy, the output impedance is modified at the fundamental and harmonic frequencies to compensate for the line impedance mismatches among DG units, which results in

A high step-up isolated forward–flyback DC–DC converter with pulse frequency modulation (PFM) is presented in this paper. The proposed converter has features of both a forward and a flyback converter and can deliver energy during the turn-on and turn-off intervals in a switching period. In addition, by utilizing resonance it can achieve zero-voltage switching (ZVS) for the primary switches and zero-current

The LCL filter is widely used in grid connected converters for good harmonic mitigation performance. With pulse width modulation strategy, converter terminal voltage contains various sideband harmonic components together with expected components corresponding to the modulation wave, especially under a low switching frequency. Considerable resonant current can be generated if the undesired sideband

A modified topology to obtain a high efficiency bidirectional type DC–DC converter without magnetic coupling is proposed in this paper. The modified circuit contains four switches with their body diodes, two inductors and a capacitor, and the topology arrangement uses two boost converters to develop the gain. The input current of the modified topology is divided between two different values of inductors

State of charge (SoC) balancing and accurate power sharing have been achieved among distributed batteries in a DC microgrid without a communication network by injecting an AC signal. The frequency of the generated signal is proportional to the SoC of a predefined master battery and it is used for the other batteries as a common variable to estimate the SoC and output power of the master battery. Based

Wide band gap semiconductor device silicon carbide (SiC) metal oxide semiconductor field effect transistors (MOSFETs) have many advantages and are considered to be the most promising alternative to silicon (Si) insulated gate bipolar transistors (IGBTs) in low-/medium-voltage fields. However, a faster switching speed results in more serious electromagnetic disturbance problems in the application of

A new three-phase buck/boost/buckboost power factor correction rectifier is presented in this paper. For the converter, only two high-frequency switching actions exist in each sample period, and only one inductor is used. As a result, system efficiency can be improved. The commutation procedures are analyzed for the three modes, the controller design of the rectifier is discussed, and the output duty

The right-half plane (RHP) zero in the control to output voltage transfer function of a boost converter operating in the continuous conduction mode limits the loop bandwidth. By injecting a scaled version of the inductor current into the loop, it is possible to shift the zero from the right-half plane to the left-half plane, which leads to increased stability of the control loop. This solution generates

With the rapid development of semiconductor technology, the applications of silicon carbide (SiC) MOSFETs have been booming in recent years, where short-circuit fault protection plays an important role. In this paper, voltage and current waveforms under different short-circuit faults are analyzed. Then, two types of turn-off modes, namely a soft turn-off mode and a two-stage turn-off mode are introduced

Due to an unfortunate oversight, the funding number of the Fundamental Research Funds for the Central Universities has been given erroneously. It should be read: 2013/2019B04114

A new structure for doubly fed induction generator (DFIG) wind farms with coordinated power control under grid fault conditions are proposed in this paper. The proposed structure uses one grid side converter (GSC) and one energy storage system (ESS) for the entire wind farm unlike conventional structures, which have one GSC for each of the DFIGs. A converter loss decrease and a reliability enhancement

This study implemented a 30 kW, 750 Vdc, silicon-carbide (SiC)-based uninterruptible power supply(UPS) applied it on a three-phase four-leg inverter. For component selection, LC filter and DC-link capacitor were designed based on the PSIM simulation. SiC MOSFET was used to achieve higher efficiency and better reliability than the conventional Si IGBT-based UPS applications. Furthermore, desaturation

In this paper, an online junction temperature monitoring method based on the on-state voltage under high collector current density measurements for IGBT power modules is proposed. Unlike the conventional junction temperature monitoring method, the presented method can extract the junction temperature during operation without altering the modulation strategy or topology of the converter. The proposed

The soft-switching buck inverter, which is mainly applied to solve the contradictions between the switching frequency and the shoot-through problem along with the dead-time effect, is proposed in this paper. A detailed analysis of the relationship between the range of the duty ratio to realize soft-switching as well as the additional voltage stress and the current stress is conducted. In addition,

With the rapid development of DC transmission technology, DC circuit breakers, the key equipment for DC fault handling, have become a research hotspot of scholars. This paper proposes a novel hybrid DC circuit breaker topology to improve the shortcomings of traditional hybrid DC circuit breakers. Traditional hybrid DC circuit breakers use too many IGBTs, which results in a large volume and a high cost

Under an unbalanced network, model predictive control (MPPC) with a new definition of the instantaneous reactive power has attracted a great deal of attention due to its simple control structure and outstanding steady-state performance. However, the reactive power cannot precisely trace the nonzero reference. In this paper, a model predictive DC-component power control (MPDCPC) is proposed to tackle

Due to an unfortunate oversight some equations (4, 5, 6 and 7) have been given errorneously.

This study proposes a design of an inner control loop for the load torque control of an electric load simulator (ELS), which is specifically designed to simulate load torque (i.e., load) for mechanical equipment. By mainly drawing on linear active disturbance rejection control, a mechatronic model-based inner loop controller of ELS is designed using measured torque to reduce the complexity of the estimator

Flux estimator (FE) is critical for achieving high-performance sensorless drive of induction motors. A voltage model (VM) is an excellent candidate for a FE since it does not require speed information and has a simple structure. A VM using a closed-loop style has excellent sensorless drive capability over a wide speed range. However, it is limited by the uncertainties such as offset and parameter mismatch

The carrier phase-shift PWM strategy is widely used in modular multilevel converters to satisfy the driver demands of the numerous switches in submodules. However, the traditional carrier phase-shift PWM strategy can cause an imbalance phenomenon in the submodule capacitor voltages, which deteriorates the system working performance. This study develops a mathematical model of an MMC system, which is

Although the silicon carbide (SiC) metal–oxide–semiconductor field-effect transistor (MOSFET) is superior to the conventional silicon (Si) insulated gate bipolar transistor in terms of switching performance, the switching losses of SiC devices increase rapidly by hard switching when the switching frequency (fsw) increase to hundreds of kilohertz (kHz). This paper proposes an auxiliary zero-voltage-transition

In a three-phase multilevel cascaded inverter (MLCI), when a failed module is bypassed, the number of modules in each phase becomes unbalanced. Under this condition, a method to obtain a balanced three-phase output is to move the neutral point of the MLCI. The neutral-point shift (NS) method has attracted a great deal of attention since the output of the inverter has a relatively low harmonic distortion

Silicon carbide (SiC) metal–oxide–semiconductor field-effect transistors (MOSFETs) are expected to be an attractive replacement for Si MOSFETs in high power applications due to their high blocking voltage, high switching speed, and low switching losses. However, a high switching speed can lead to voltage and current overshoot as well as oscillation during the switching process, which results in additional

With the large number of applications for multi electric aircraft (MEA), the power capacity of the aviation static inverter (ASI) has been continuously improved. Therefore, more and more modular parallel-based topologies are being used in the ASI to achieve power expansion. Combined with carrier phase-shift modulation, the harmonic components of a system can be further reduced. However, due to the

This paper proposes a model predictive control (MPC) algorithm designed for nine-switch converter with output filter (NSCOF) to control two three-phase AC loads independently. A state function of each leg of nine-switch converter (NSC) is established to characterize the internal conditions of the NSC because the traditional model of the NSCOF does not involve the interior model of the NSC. Based on

Inaccurate reactive power sharing and voltage distortion at the point of common coupling (PCC) always exist in a parallel inverter system due to feeder impedance mismatches and nonlinear load disturbances. An enhanced inverter control scheme through an output impedance adjustment is proposed to address these issues. Inverter output impedance is regulated considering fundamental and harmonic frequencies

The junction temperature of power semiconductors is a critical parameter during reliability evaluation. The incorporation of long-term mission profiles, such as power loadings and ambient temperature, into lifetime and reliability evaluations of power semiconductors increases the computational burden. Thus, there is an urgent need for a more accurate method for junction temperature acquisition. Current

Magnetic resonant wireless power transfer (MR-WPT) has become a significant method for powering the measurement units in landslide monitoring boreholes. This paper focuses on the effects of quality factor, coupling distance and load on the power transfer stability, sensitivity and performance of an MR-WPT system. Firstly, through a numerical model of an MR-WPT, the effect of quality factor and coupling

This paper presents a single-switch high-voltage gain DC–DC converter with a coupled-inductor. The proposed converter overcomes the drawbacks of traditional DC–DC converters such as insufficient boost capability and high stress on the devices. Its advantages include having a small number of switch devices, low voltage stress on the switch, and a high voltage gain. This paper analyzes the operating

A signal injection method without torque ripple is presented to estimate the stator winding temperature of a surface-mounted permanent magnet synchronous machine (PMSM), where the temperature is estimated based on the stator resistance. First, the current signal (Δid*) is injected into the current control loop to produce DC current offsets used to calculate the stator resistance, where the injected

Accurate estimation of the lithium-ion battery state of charge plays an important role in the real-time monitoring and safety control of batteries. In order to solve the problems that the real-time estimation of the lithium-ion battery is difficult and the estimation accuracy is not high under various working conditions, a lithium-ion battery is taken as a research object, and the working characteristics

For the five-level active neutral point clamped (5L-ANPC) converter, the coupling problem between the DC-link capacitor voltages and flying-capacitor (FC) voltages will increase the capacitor voltage fluctuations. The capacitor voltage fluctuations and current harmonics of the space vector pulse width modulation (SVPWM) are less than those of the sinusoidal pulse width modulation (SPWM), because the

To solve the inherent contradiction between convergence speed and optimization accuracy in the traditional optimal control strategy for the excitation parameters of SRGs, a novel optimal control strategy for the excitation parameters is proposed. In this strategy, the turn-off angle is fixed at its optimal value and kept constant, and the turn-on angle is optimized through two steps. In the first step

This article presents an integrated control scheme to improve power sharing for power management and voltage regulation in DC microgrids. The proposed scheme considers the available power and the stochastic nature of sources to achieve adequate power sharing among them. Therefore, it achieves effective utilization of each source. In addition, the effective use of energy storage systems (ESSs) is also

This paper proposes an efficient bridgeless power factor corrected (PFC) modified single ended primary inductor converter (SEPIC) for arc welding power supplies (AWPS). The overall configuration is composed of two converters: (1) a modified bridgeless SEPIC PFC converter, which is controlled by a PI controller to achieve a high power factor and fast response; and (2) a full bridge buck converter with

Efficient extraction of the maximum power from photovoltaic (PV) systems under inherently variable weather conditions is a key issue that has been tackled in recent years. Maximum power extraction techniques are relevant for increasing the penetration of PV systems into electric systems. This paper presents an averaged current mode control strategy as a maximum power extraction technique in a photovoltaic

All-metal induction heating (IH) systems have been introduced to heat both ferromagnetic and non-ferromagnetic pots using dual resonant frequencies. They are designed for heating ferromagnetic pots using a first harmonic operation mode (FHOM) and for heating the non-ferromagnetic pots using a third harmonic operation mode (THOM). All-metal IH systems employing dual resonant frequencies consist of an

An advanced predictive current controller (APCC) based on deadbeat (DB) control theory for permanent magnet synchronous motor (PMSM) drives is proposed in this paper, where the optimum voltage vector is computed offline by solving an optimization problem. The optimum voltage vector along with a zero-voltage vector (ZVV) is applied to the motor under steady state condition to minimize ripples in the

The traditional single-stage boost LLC resonant AC/DC converter has been widely studied due to advantages such as few power stages, high power factor, and soft switching. However, it also has several disadvantages, such as a low and narrow input voltage, a DC bus voltage that is much higher than the input voltage, and high stress of the switching devices. Therefore, it is generally used in power grids

Current-fed isolated bidirectional DC–DC converters (CF-IBDCs) play an important role in battery energy storage systems. However, the closed-loop dynamics is rather slow with conventional proportional–integral controllers because a precise mathematic model remains absent for optimization. In this paper, a simple precise mathematical model is presented to describe the large and small-signal behaviors

High amounts of harmonics cause noise and electromagnetic interference to nearby systems. Pulsewidth modulation (PWM) techniques are used to reduce the amount of harmonics near the multiples of switching frequencies. To trim down the noise and electromagnetic interference and improve the quality of the output voltages, different types of constant and variable switching frequency random PWM techniques

The power ripple in the input filter is normally ignored in the conventional model predictive control scheme (MPC) of an AC/DC matrix converter under imbalanced grid voltage conditions. Unfortunately, this power ripple causes output power and current ripples. Some methods compensate this power ripple to obtain a ripple-free output current. However, these methods are generally complicated due to the

In this paper, a control method for a 3-bridge LLC resonant converter operating with a wide output voltage control range is described. Duty changes that stem from switching devices cause topology transitions that allow the converter to shift sequentially across four operating modes, where the primary resonant tank circuits and the secondary terminals can be connected in parallel or in series making

Multiple output LED drivers are necessary to achieve better performance and higher reliability in street lighting, tunnel lighting and LCD background lighting applications. Based on LCL-T constant-current characteristics, a modular multiple output LED driver is proposed in this paper. The LCL-T rectifiers are connected to the same voltage bus and work like current sources. However, since there are

There are 6 modes in the full working state of a traditional 3-phase rectifier, and each mode is necessary for power factor correcting and for realizing the corresponding DC-link voltage. It is obvious that too many modes in the full working state increase the switch stresses, which results in high switching loss and increased economic cost. Reducing the number of working modes is a feasible solution

This paper proposes an identification method for mechanical parameters based on position control. To improve motion control performance, the moment of inertia and friction components must be considered. Based on mechanical equations, the proposed method estimates the moment of inertia, viscous friction coefficient, and Coulomb friction in the off-line state. Mechanical parameters are obtained from