Fast and accurate acquisition of voltage components is the basic requirement for grid-tied inverters to realize various control under unbalanced grids. In view of this situation, a delay sampling period filter, which rapidly separates each voltage component by delaying two sampling periods in dq frame, is proposed in this article. In view of the noise interference, a delay operation period filter (DOPF)

This article presents an auxiliary circuit for the current-fed half-bridge (CFHB) converter, aiming to clamp the high voltage spikes across the main switches caused by the energy stored in the leakage inductance of the transformer. This circuit also provides zero-current switching (ZCS) to the main switches at turn- off . Moreover, the rectifier diodes and the auxiliary switch operates under ZCS at

Recently, several publications have discussed the design of LCL filters and current controllers for grid-connected converters. However, the focus was the LCL filter used as a differential mode (DM) filter. Besides its conventional application as DM filter, a modified LCL filter configuration can be used as an integrated common mode (CM) and DM filter, which is particularly interesting for transformerless

The generation of high dc voltages is necessary for feeding many technical applications and testing the insulation material of high-voltage dc transmission lines and ac power cables with long lengths. The article proposes a modular multiplier high-voltage dc generator with integrated Cockcroft–Walton (CW) circuits. In this new topology, CW circuits are connected in series to produce a high dc output

It is more efficient to employ inductive power transfer (IPT) systems to charge automated guided vehicles (AGVs) than traditional plug-in systems. In order to provide independent and different charging power for the driven system and the control system of AGVs simultaneously, this letter proposes a coaxial dual-receiver structure and a decoupling circuit, which utilizes a passive component connected

Dual stator winding induction machines (DSWIMs), which have two sets of three-phase windings with unequal pole pairs in their stator and a standard squirrel cage rotor, have overcame the narrow speed operation region and circulating current problems exists in other types of dual winding machines. These advantages are resulted from the independent operation of their winding sets. The independent operation

The low on -resistance of wide-band-gap (WBG) transistors is a key feature for efficient power converters; however, the anomalous loss in their output capacitance ( C OSS ) severely limits their performance at high switching frequencies. Characterizing C OSS losses based on the large-signal measurement methods requires an extensive effort, as separate measurements are needed at different operation

Hybrid modular multilevel converter that consists of a combination of half-bridge submodules and full-bridge submodules (FBSMs) can block dc fault current. However, in the case of distant bulk power transmission, the large excess energy that stored in the long-distance line will greatly affect the fault clearing time and FBSM capacitor overvoltage. During the fault clearing process, several commutations

Efficient dc–dc power-conversion with wide-span voltage-regulation is crucial to a sustainable and robust power electronics system. Dual-active-bridge (DAB) offers straight-forward regulation and its transformer enables voltage step-up/down required for many applications, such as battery chargers and bus converters for dc distribution systems. However, losing soft-switching at light loads or when operating

This letter proposes an online capacitance estimation method for the modular multilevel converter. In the prevalent methods, the inherent second-order circulating current or the injected low-frequency current/voltage component is utilized to calculate the submodule (SM) capacitance. In this letter, the relationship between the voltage variation of an SM capacitor in one fundamental period and the driving

The series-connected system is widely used in the medium or high voltage applications. For the series-connected inverter system, the phase angle synchronization should be guaranteed to ensure the total output voltage. Usually, a centralized controller is used to send the same voltage command to each module downstream. In order to improve the flexibility and scalability of the modular system, a decentralized

This letter proposes a novel capacitor condition monitoring method for modular multilevel converters (MMCs) based on reference submodules (SMs). It significantly enhances the capacitor monitoring accuracy by making full use of the SM voltage sensor measurement range. Accuracy comparison between the existing method and the proposed method is conducted to quantify the improvement of accuracy. Moreover

In magnetic resonant wireless power transfer (WPT), relays are placed between a transmitter and a receiver as a means of increasing both the operating distance and the power transfer efficiency, but this makes the analysis of the WPT system more complicated. In this letter, we derive a mathematical expression for the power transfer efficiency with an optimal load resistance based on an equivalent circuit

The dc in a power system may be caused by geomagnetic disturbances that are the result of solar storms and high-altitude nuclear detonations. Increased inverter-based generation is also contributing to small dc injection into the power systems. The resultant dc could have serious consequences for the power systems as it may drive power transformers into saturation, cause transformer internal heating

A compact rectenna with a wide input power range is proposed for wireless power transfer (WPT). Two different diodes, having distinct operating powers, i.e., high-input-power diode and low-input-power diode, are introduced to the rectenna design for extending the operating input power range. A mid-inductor is placed in the rectifying circuit to isolate the radio frequency (RF) signal from dc power

Commercial gallium nitride (GaN) high-electron-mobility transistors used for power electronics applications show superior performance compared to silicon (Si)-based transistors. Combined with an increased radiation hardening properties, they are key candidates for high-performance power systems in a harsh environment, such as space. However, for this purpose, it is key to know the potential failure

A new strategy framed in the field of model predictive direct current control applied to surface permanent magnet synchronous generator (SPMSG) is presented. Compared to conventional space vector control systems, the proposed predictive strategy reduces the number of PI regulators and maintains the advantages of a fixed switching frequency. It also performs a faster response providing a smooth electromagnetic

Dynamic wireless power transfer (WPT) for charging electric vehicles (EVs) overcomes some of the problems associated with EVs battery size and weight as well as distance range limitation and long charging duration. High efficiency and fixed output voltage of WPT systems are of great importance for reducing operating cost and facilitating battery charging, respectively. On the other hand, utilizing

In this letter, a new coupling structure for dynamic wireless power transfer (DWPT) systems is proposed. Bipolar coils are symmetrically placed on the transmitter unipolar coils, resulting in natural decoupling between the bipolar coils and the unipolar coils. This special structure can mitigate the self-couplings between the adjacent unipolar transmitter coils and hence facilitate the design of the

The active capacitor concept based on power electronic circuits has been proposed recently to exceed the physical limit of the passive capacitor. It retains the physical convenience of use as a passive capacitor and has the potential to increase either the power density or the lifetime depending on the applications. However, the cost of the existing design by using ceramic or film capacitors to achieve

High thermal and electrical stress, over a period of time tends to deteriorate the health of power electronic switches. Being a key element in any high-power converter systems, power switches, such as insulated-gate bipolar junction transistors (IGBTs) and metal-oxide semiconductor field-effect transistors, are constantly monitored to predict when and how they might fail. A huge fraction of research

This article presents a cost-effective prognostic method for the bond wires in the insulated-gate bipolar transistor (IGBT). Consider that the crack propagation in the wire bond leads to the bond wire liftoff, the corresponding state equation is established from the fracture mechanics theory, with the consideration of the uneven distribution of the temperature swings. Hence, the proposed model can

Series–series (SS) and series–parallel (SP) topologies are widely used in resonant inductive coupling wireless power transfer systems for various applications. However, the selection of an appropriate topology to achieve higher output power or higher efficiency is typically difficult because design optimization of the circuit parameters (e.g., characteristic impedance, load resistance, and mutual inductance)

MnZn-based ferrite materials like the EPCOS N87 or K2004 are commonly used as magnetic cores in inductive power transfer (IPT) applications. However, the performance and the reliability of IPT systems are limited by ferrite's intrinsic brittleness and low flux density saturation point. In this article, a study of nanocrystalline-ribbon-based magnetic cores for IPT applications is presented. Finite

To improve the efficiency of high frequency inverter (HFI) in inductively coupled power transfer system, pulse density modulation (PDM) is often used. However, the output current of the HFI fluctuates seriously, especially at light load. It affects the stable operation of the system and the implementation of zero voltage switching. In this article, an improved pulse density modulation (IPDM) is proposed

Resonant rectifier topologies would be a promising candidate for achieving simple, compact, and reliable single-stage wireless power transfer (WPT) receiver if not for the lack of good dc regulation capability. This article investigates the problems that prevent the feasibility of single-stage dc regulation in resonant rectifier topologies. A possible solution is the proposed differential resonant

In this article, an optimal design procedure of shunt RC damped LCL filter is discussed. The proposed design procedure finds the minimum damping resistance to guarantee the stability of the grid-current controller without affecting the effectiveness of the filter. This minimum value is derived using the factorized filter input admittance and filter forward transadmittance. The proposed factorization

Quasi-Two-Level PWM Operation of modular multilevel converters enables a significantly smaller amount of installed module capacitance, even with low output frequencies required for machine drives. This article presents an implementation of this operation mode with an improved current control that leads to fast and precise current transitions. The proposed current control combines a deadbeat controller

Three-phase meander-type dynamic wireless power transfer is ideal for the power supply or charging of rail vehicles. However, there is a lack of systematic analysis and design of the three-phase receiver. To achieve the compact design of the three-phase receiver in practical applications, this article studies the compact three-phase receiver with overlapped receiving coils and ferrite core. Based on

Inductive power transfer (IPT) systems have many unique benefits compared to conventional plugged-in systems. The coupling pads in IPT systems are inevitably misaligned in many practical applications, thus leading to variations of the transferred power and efficiency that necessitate the use of complicated control for output regulation. A common solution is to use two IPT converters with opposite trends

Model predictive control (MPC) methods are popularly employed in modular multilevel converters (MMCs) due to their fast dynamic response and multiobjective control capability. However, they present some inherent problems, such as computational complexity, variable switching frequency, poor steady-state performance, and tedious weighting factor selection. This article develops a deadbeat predictive

The increasing penetration of distributed generators in low-voltage distribution grids may lead to distribution transformers, also a smart transformer, experiencing the reverse power flow, which is less as compared to the forward power flow in the current electric grid. This article proposes an asymmetrical bidirectional dc–dc (AB-DC/DC) converter, which has two partial-scale rectifiers of an active

Direct current (Dc) networks have proven advantages in high voltage direct current (HVDC) transmission systems, and now they are expanding to medium- and low-voltage distribution networks. One of the major challenges is to develop reliable dc–dc voltage transformation achieving high efficiency and performance, especially at high voltage and high step ratio. New resonant modular multilevel topologies

This article proposes a mission profile-based reliability prediction method for modular multilevel converters (MMCs). It includes key modeling steps, such as long-term mission profile, analytical power loss models, system-level and component-level thermal modeling, lifetime modeling, Monte Carlo analysis, and redundancy analysis. Thermal couplings and uneven thermal stresses among submodules are considered

This article proposes a line-current ripple minimization pulsewidth modulation strategy with reduced zero-sequence circulating current (ZSCC) for two parallel three-phase two-level converters. We split each 60° sector into six subsectors, each applies the nearest three vectors to ensure minimal line-current ripple. To reduce the ZSCC, we further investigate all vector sequences of the nearest three

This article presents a carrier-based pulsewidth modulation (PWM) strategy to reduce the common-mode voltage (CMV) with output harmonic distortion minimization for three-level neutral-point-clamped (NPC) inverters. The proposed method is first presented for three-level NPC inverters, and then, generalized for odd n -level inverters including NPC and cascaded inverters. With the help of base voltage

In consumer electronics, high power density power adapters are designed to minimize the adapter size. As a result, the components are getting very close and the near-field coupling issue tends to be severe. This compromises the performance of electromagnetic interference filters, especially at high frequencies. This article investigates near-field capacitive couplings and the reduction techniques in

SiC devices can upgrade the inverter performance to a new level by its potentially more than ten times higher switching speed compared to its Si counterpart. However, the high switching frequency and dv/dt, di/dt worsen the electromagnetic interference. Reduction of the common mode (CM) noise of the non-isolated photovoltaic (PV) inverters is addressed by many researchers through adding filters or

In this article, the common-mode (CM) noise model is developed for an ac–dc–ac system with paralleled power modules. The CM noise contributions from both rectifiers and motor drives are analyzed. The interaction between the ac/dc rectifiers and dc/ac motor drives is explored. The CM noise reduction techniques which include a decoupling inductor technique and a CM noise balance technique are proposed

Output impedance characteristics of interfaced converters of energy sources are the important indicators to assess the anti-interference ability of the dc microgrids. However, the output impedance is often approximately modeled by neglecting the impacts of delay units. In order to accurately study the anti-interference ability, the output impedance of an energy storage system is modeled with the consideration

Current-fed switched inverter (CFSI) is a high-gain inverter topology suitable for applications which have limited input dc source voltage, e.g., roof-top solar applications. A very high step-up ratio between ac output and dc input along with inherent shoot-through protection makes it suitable for low-power stand-alone inverter applications. In this article, a novel interleaved topology for CFSI (ICFSI)

This article presents a novel adaptive backstepping based nonlinear control scheme incorporated with machine loss reduction and parameter uncertainties for grid-connected doubly fed induction generator (DFIG) driven wind energy conversion system (WECS). The proposed nonlinear controller is developed to stabilize both the grid and rotor side current control loops of direct-drive DFIG-based WECS. Traditional

In this article, a novel coupled inductor-based high step-up dc–dc converter is proposed. The introduced converter benefits from various advantages, namely ultrahigh voltage gain, low voltage stress on the power switches, and continuous input current with low ripple. Therefore, the presented converter is suitable for renewable energy applications. By utilizing clamped circuit, voltage spike of the

A novel quasi-two-stage multifunctional inverter (QMFI) for photovoltaic (PV) applications is proposed in this article. With the help of the quasi-two-stage architecture, part of active power can be directly transferred from PV arrays to the grid or load within a single power conversion stage and hence improve the efficiency. In addition to active power transfer, both the realization of maximum power

Photovoltaic (PV) systems operating in the outdoor environment are vulnerable to various factors, especially dust impact. Abnormal operations lead to massive power losses, and severe faults as short circuit may cause safety problems and fire hazards. Therefore, monitoring the operation status of PV systems for timely troubleshooting potential failure and effective cleaning scheme are the focus of current

Most maximum power point trackers (MPPTs) for electromagnetic energy harvesters (EMEHs) are based on resistive matching technology, where the input resistance of the MPPT is made equal to the magnitude of the output impedance of the harvester. This is valid when the output reactance of the EMEH is much smaller than its output resistance. However, some EMEHs, such as permanent magnet generator, have

The class-E converter with soft-switching has been widely used in high-frequency wireless power transfer (WPT) system. However, the high voltage stress on the switch limits its application. In this article, a compound voltage-clamped class-E converter, consisting of an auxiliary clamped circuit and class-E converter, is proposed in the WPT system to solve the issue. Through impedance analysis, SP (series–parallel)

Lithium-ion (Li-ion) batteries endure substantial energy loss and power recession under cold environments, requiring to be heated before starting normal operations in electric vehicles (EVs). Currently, many internal ac heating approaches powered by batteries have been proposed to achieve a fast heating speed, high efficiency, and good uniformity. However, due to the bulky size, high cost, and low

The zero-voltage switching (ZVS) T-type dc–dc converter has been proposed as an alternative to the conventional ZVS pulsewidth modulated (PWM) full-bridge (FB) converter. Although it has a number of advantageous features, the ZVS T-type dc–dc converter is not well known among power electronic engineers, and the topology has thus been neglected. In this article, the operation of the dc–dc ZVS T-type

An impedance-source inverter can offer the voltage buck-boost function in a single-stage circuit. Its advantages include a simple structure, safety, and reliability. This article proposes a Cockcroft–Walton multiplier voltage (CWMV) impedance-source inverter consisting of a modified CWMV circuit and an impedance-source inverter. There are two types of circuits: the CWMV Z-source inverter (ZSI) and

A nonisolated soft-switching bidirectional dc–dc converter (BDC) with interleaved technique and built-in transformer (BT) is proposed for the interface between the energy storage system and dc microgrid bus in this article. A T-type neutral-point-clamped circuit is integrated into an interleaved conventional buck–boost BDC to obtain a high voltage-gain ratio and decrease voltage stresses of power switches

Due to the presence of parasitic elements in switching devices and circuit realization, crosstalk phenomenon in bridge-leg configurations is unavoidable. A passive resonant level shifter that can suppress the effect of the crosstalk and deliver a low off -state gate-source voltage to reduce the forward voltage drop of the body diode of SiC mosfet s is presented. The circuit is composed of two parts

In this article, a novel high conversion ratio dc–dc converter suitable for photovoltaic applications is presented. Utilizing single-switch and single-magnetic core, low ripple input current and low voltage stress across the semiconductors are the major advantages of the proposed converter. In order to provide a soft-switching condition for the converter switch at a wide range of output power, a passive

In this article, we describe a new approach for the compact and energy-efficient cooling of converters where multiple miniaturized microfluidic cold plates are attached to transistors providing local heat extraction. The high pressure drop associated with microchannels was minimized by connecting these cold plates in parallel using a compact three-dimensional-printed flow distribution manifold. We

This article presents two hybrid multioutput buck–boost quasi-Z-source converters (q-ZSCs) capable of giving two dc and one ac outputs simultaneously from a single dc input. One dc and the ac outputs of the proposed multioutput q-ZSCs have both buck and boost capabilities and the other dc output has the property of boosting the input voltage, thereby capable of giving a wide range of voltage gain both

The conventional five-phase finite-control-set model predictive control (FCS-MPC) suffers from heavy computational burden. Meanwhile, the control set with finite vectors inevitably leads to deteriorated operation performance. This article proposes a novel FCS model predictive current control (MPCC) with continued modulation. A cascaded optimization procedure is proposed, which includes main virtual

This article presents a new rotor speed observer for the sensorless control of stand-alone brushless doubly fed induction generators based on the control winding flux model reference adaptive system structure. The observer is incorporated in the control strategy for regulating the terminal voltage magnitude and frequency under the different operating conditions. The capability of the proposed observer

This article presents a progressive comparison of predictive torque control (PTC) algorithms for a five-phase induction motor fed with a two-level five-phase inverter. The extension of three-phase PTC to the five-phase motor, introduces current harmonics of the order 10n $\pm$ 3 (n = 0, 1, 2.. .), which are not responsible for torque/flux production. The inherent disadvantage of PTC is being a variable

Considering the propagation delay, dV SW /dt immunity, and power dissipation issues in the bootstrapped high-side gate driver design, a monolithic high-voltage dc–dc buck converter with a high-speed dynamic level shifter and improved gate drive buffer is presented in this article. With the introduction of instantaneous dynamic current, the propagation delay of the level shifter is reduced to 1.13 ns

A control scheme is presented for a dual inverter drive with a floating capacitor bridge, with decoupled motor and capacitor dynamics. A stator current reference frame is used that decouples the real and reactive power components of the motor and enables the decoupling of the motor and capacitor dynamics. Apart from the high frequency voltage ripple due to the inverter switching pattern, the capacitor