Silicon superjunction MOSFET (Si SJMOS) with SiC Schottky diode is a popular choice in single-phase dual-boost PFC converter applications due to their lower cost, standard gate driving voltage, and high reliability. SiC Schottky barrier diode (SBD) can mitigate the issue of poor reverse recovery of the body diode of Si SJMOS and improve the converter's efficiency. SiC MOSFETs are now available in the voltage range of 600-650V, where they can be used as an alternative to the Si SJMOS. It is generally believed that using SiC MOSFET in place of Si SJMOS will increase the converter's efficiency. However, SiC MOSFET in this voltage range (600-650V) has a similar on-state performance to Si SJMOS. On the other hand, SiC MOSFET is expensive when compared with Si SJMOS. Also, being a new device, the reliability data for SiC MOSFETs from the field is not available. This work presents a comparative study of the switching dynamics of similarly rated SiC MOSFET and Si SJMOS, where SiC SBD is used as a free-wheeling diode. Two sets of 650V SiC MOSFET and Si SJMOS of different current ratings are considered for comparison. The experiments are conducted for a range of gate resistance and operating currents. © 2022 IEEE.

This paper presents a closed-loop controller design approach for a single-phase (1φ) pulse-width modulated (PWM) high frequency (HF) AC inverter, supplying the non-linear load for space application. Control challenges in HF inverter are highlighted compared with 50/60 Hz conventional inverter. Considering HF PWM inverter with resistive load, the parameters for two-loop control structure are decided to meet specific stability criteria and steady-state performance. Re-tuning of the controller is performed to support non-linear load (uncontrolled diode bridge rectifier) with trap filters. The possibility of connecting damper resistors in series with the trap filters is also explored for better control loop shaping. Analog realization of the controller is also discussed in brief. The proposed controller design is validated experimentally by transferring 0.5 kW power through a 50 V peak, 10 kHz AC system. © 2022 IEEE.

An asymmetrical six-phase machine (ASPM) with two isolated neutral points is analyzed in two orthogonal planes-one of these planes is associated with electromagnetic energy transfer. The energy-transferring plane of ASPM has two regions-linear and overmodulation (OVM). Unlike the linear region, the average voltage injected in the non-energy transferring plane of the OVM region is non-zero. The efficacy of carrier-based implementation of an equivalent space-vector PWM (SVPWM) technique to reduce the computational burden is well-known in three-phase inverter literature. Although carrier-based implementations of popular SVPWM techniques of ASPM are researched for the linear region, such carrier-based implementation doesn’t exist for the OVM region. Moreover, a direct extension of the carrier-based strategy in the linear region to the OVM region isn’t possible because it requires the calculation of non-zero voltages in the non-energy transferring plane. This paper presents a carrier-based implementation of one of the SVPWM techniques in the OVM region, resulting in minimum RMS harmonic voltage. The proposed technique is a natural extension of an important known PWM technique applied in the linear region. The proposed algorithm generalizes the duty signals in terms of maximum, middle, and minimum of three intermediate signals. These duty signals are then compared with two carrier signals to generate the required gating pulses. The proposed algorithm is validated through simulation and experiment on a hardware prototype at a maximum power of 4.5 kW.

In this paper, small signal modeling of series resonant converter (SRC) operating under variable frequency modulation is presented. Noting that the existing small signal models are of higher order and mathematically complex, a reduced order model is proposed to make the control loop design easy. Both time-domain-based exact state plane analysis and averaging technique of an electrical variable are adopted to derive control-to-output transfer functions of SRC. Accuracy of the proposed approach is validated using LTSPICE simulation.

This paper presents a design and operation strategy for a single-phase single-stage Dual active bridge (DAB) based AC-DC converter. Conventional AC-DC power conversion happens in two stages, an active front end converter followed by an isolated DC-DC conversion stage. Conversion with multiple stages lead to lower efficiency and power density due to presence of an intermediate DC link capacitor and hard-switched rectifier. This paper utilizes a single stage conversion topology where the grid side converter is switched only twice in a line cycle resulting in reduced switching losses. A modulation strategy is discussed which results in unity power factor operation and soft switching. Two separate design strategies are proposed which lead to minimization of the DAB rms and peak of inductor current. Simulation results are presented for a 2.5 kW converter which verify the effectiveness of the design technique.

Model Predictive control is a modern method of nonlinear control which gives superior performance with the cost of increased computational burden. In this paper, continuous control set model predictive control (CCS-MPC) for buck converter is proposed. This control strategy achieves constant switching frequency and retains the advantage of faster response of Model predictive control(MPC). The proposed algorithm is based on sampled data model of buck converter. The computation related to solution of a continuous optimization problem is done through a polynomial approximation of a transcendental function. The paper also shows how this approximation is valid for all practically designed buck converters. The proposed control strategy is verified in simulation and compared with experimental results, and it shows good performance for both reference tracking and disturbance rejection. It is superior compared to classical PI with lead controller and is about six times faster than conventional PI with lead controller.

This paper presents a carrier based implementation of Space Vector Pulse Width Modulation (SVPWM) of dual matrix converters (MCs) using synchronously rotating vectors. Usage of only synchronously rotating vectors ensures the elimination of differential and average common mode voltages which lead to circulating currents and electromagnetic interference (EMI) problems respectively. The proposed strategy is an alternative way to achieve SVPWM, but it doesn't involve the knowledge of space vectors once it is derived. Also, it avoids any trigonometric and division operations that could be needed to implement the SVPWM using the general space vector approach.

This paper presents an analysis and comprehensive comparison between the passive filter component requirements of a matrix converter and a DC-link based back-to-back converter. Proper design of the filter components requires the estimation of the switching frequency components present in various voltages and currents. An accurate estimation of different ripple quantities is presented by simple analytical expressions and verified by MATLAB/Simulink simulations. The filters are designed and a quantitative comparison of the passive components is done.