A Transformer-Less Multiconverter Having Output Voltage and Frequency Regulation Characteristics, Employed with Simple Switching Algorithms

The attractive features of the direct AC-AC converters increase their use in many applications such as voltage control for a heavy-duty load that has a high time constant, AC machine drives, and heating systems based on the induction process. These converters process power in single-stage having simple circuit topologies with reduced switching devices and circuit components. These characteristics lead to the efficient power conversion process. The use of a low-frequency input transformer with multiple output tapping for the regulation of output voltage and frequency is one of the major sources of cost, size, and conversion losses. The complication in the switching algorithms is also the main concern in these converters. The preceding deficiencies lower their potency to be used in daily life. The costly controllers or processors are to be employed to realize the complex control techniques or algorithms. That increases the overall cost and circuit complication. This paper introduces the simple control techniques employed to a novel transformer less multi converter to have the various ac outputs for voltage and frequency regulation. The validation of power circuit and control schemes is tested through the simulation and practical results obtained in Simulink and practical setup respectively.

Intelligent Protection of VSD Transformers

Variable Speed Drives (VSD) protect themselves as well as the driven motors. In contrast, the isolation input transformer typically requires its dedicated protection. Unlike distribution and power transformers, the protection of VSD duty transformers need to consider several additional aspects, such as non-sinusoidal current with harmonic content, multi-winding design, phase-shifted converter windings etc. This paper aims to explain the challenges related to protection of VSD transformers. A guideline for reliable transformer protection based on good design practice is proposed. Finally the possibility to integrate the transformer protection into the VSD protection scheme is being explored.

Power Balance Method using Coupled Shunt Inductor and Multiple-Input Transformer for ISOP LLC Converter

High-capacity power-supply systems using a large input voltage typically improve efficiency and can be miniaturized by dividing the input voltage into multiple small voltages, thereby minimizing the stress on the switching element and thus materializing a fast switching function. When a large input voltage is divided into small voltages in series through a DC link capacitor, power is supplied to each converter and the power of each LLC (Inductor-Inductor-Capacitor) converter can be divided and converted. However, such LLC converters, which are configured by the division of the input voltage, have power imbalance due to the parameter variation between active and passive elements of the power board, which results in an increase in the stress and heat of a particular element. As this problem of power balance necessitates a design for securing a power margin and as the heated element increases its volume, the efficiency and reliability of the LLC converter are degenerated. Accordingly, this study attempted to solve the problem of the power imbalance of LLC converters at each level using a coupled shunt inductor and multiple-input transformers sharing magnetic coupling.

An anfis converter control approach of grid connected wind/PV/battery system

The major objective of this task is a control technique for power flow management of a network associated hybrid PV-wind-battery based system with multi-input transformer coupled bidirectional DC-DC converter using ANFIS controller is introduced. The proposed system intends to fulfill the demand of load, deal with the power flow from the distinctive sources, injects surplus power into the network and charge the battery from framework as and when required. A transformer coupled boost half-bridge converter is used to tackle power from wind, while bidirectional buck-boost converter is used to outfit control from PV alongside battery charging/releasing control. A single stage full-bridge bidirectional converter is used for ac loads and collaboration with grid. The proposed converter has reduced number of intensity change stages. This enhances the effectiveness and unwavering quality of the framework. In this article Adaptive Neuro Fuzzy interference System (ANFIS) is proposed for better performance of the system. Neural system has many inputs and also has multiple outputs but the fuzzy logic has multiple inputs and single output, so the combination of this two is known as ANFIS which is utilized for nonlinear applications. The proposed paper of simulation results acquired using MATLAB/Simulink demonstrate the execution of the proposed control procedure for power stream the executives under different methods of activity.