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Summary: With the advancement of power electronic converters over the last few decades, the capability to integrate solar photovoltaics, wind, diesel generators, batteries, ultracapacitor, and electric vehicles with standalone networks or utility grids has increased. For the reliable operation of standalone networks, accurate load sharing among these sources is required. As a result, several load sharing schemes with inherent merits and related demerits are presented in the literature. This work intends to address shortcomings of earlier reported control schemes with the inheritance of associated merits using the proposed control scheme. The proposed enhanced Master–Slave control, with advanced droop control scheme, is illustrated for Master voltage source inverter with resistive line impedance and improves the steady‐state response by improving voltage and frequency profile. It reduces the voltage drop caused by load effect and droop effect, allowing the voltage and frequency regulation during load changes and distinct load conditions such as balanced linear load, unbalanced linear load, and balanced nonlinear load in standalone alternating current (AC) microgrids. Furthermore, Slave voltage source inverters independently compensate for local load demand. This paper presents precise current control and voltage control design methodology and a mathematical model for voltage control and their performance analysis in time and frequency domain. Finally, the proposed enhanced Master–Slave control for accurate load sharing among parallel standalone AC microgrids validated using real‐time simulator and experimental results is provided to verify the effectiveness of the proposed control scheme. [ABSTRACT FROM AUTHOR]

In order to control dual active bridge conventionally, control scheme such as single phase shift is used which reduces the system efficiency particularly when voltage conversion ratio differs from unity. This causes more circulating power and high current stress in switches. Moreover, voltage obtained at primary side of high frequency transformer is of two‐level only, which increases voltage stress across it. Furthermore, it has only one degree of freedom which confines its ability to regulate power flow. In this paper, a transistor clamped dual active bridge dc–dc converter is proposed with three degrees of freedom which improves its ability to regulate power flow, and because of incorporation of five‐level voltage on primary side of high frequency transformer, current stress in switches and voltage stress across high frequency transformer reduces. Mathematical modelling for the proposed converter is done for obtaining power flow equation. In addition to the phase shift control, proposed converter has two more control parameter which enhances the power flow controllability of the converter. Comparative analysis with conventional dual active bridge shows that the proposed converter is having more efficiency. Performance of the proposed converter is verified via simulation and hardware implementation. [ABSTRACT FROM AUTHOR]

This paper proposes a new single-input dual-output [SIDO] soft-switched resonant full-bridge converter, which has asymmetrical structures for the isolated multiple outputs. The proposed structure is capable of supplying different loads having dissimilar voltage-current characteristics and independent of each other. This converter features wide range of zero current switching (ZCS) turn-off and automatic load-voltage regulation. In automatic load-voltage regulation, converter maintains constant voltage without the need of change in frequency or duty ratio during load change. First, the modes of converter operation are explained and then design of key parameters have been outlined. A laboratory prototype for 380 V, 500 W as main output and 24 V, 50 W as auxiliary output for an input voltage range of 40–50 V was built-up and tested. Experimental results confirm the viability of voltage regulation, ZCS and power efficiency of the proposed converter. [ABSTRACT FROM AUTHOR]

Summary: In this work, an isolated modular resonant circuit with effective voltage regulation is presented as front‐end for multilevel inverter system to interface renewable sources of energy with micro grid. Inputs of each module of the converter are connected to low‐voltage DC sources. Modular‐structured module outputs may be linked in sequence or parallel to attain the desired DC link capacitor voltage for multilevel inverter. The proposed converter overcomes imbalance in the capacitor voltage of diode‐clamped inverter structure. Interleaved phase shift of 90° is supplied among the gate pulses of all four modules that minimizes the input‐side current ripples. An effective zero voltage switching (ZVS) is achieved over wide load range using duty cycle and frequency‐duty cycle double control method to improve system performance at light load condition. Adopting powder core magnetics and low forward voltage insulated‐gate bipolar transistors (IGBTs) reduces magnetic and conduction loss. A 12‐kW prototype of the designed modular resonant converter was verified by experimentation with a different‐level diode‐clamped inverter structures. [ABSTRACT FROM AUTHOR]