Soft-switching System Research Articles

Modified Soft-Switching System with Safe Connections of Capacitors and Inductors in Three-phase Voltage Source Inverter

Modified Soft-Switching System with Safe Connections of Capacitors and Inductors in Three-phase Voltage Source Inverter

Stability analysis and speed control of brushless DC motor based on self-ameliorate soft switching control methods

In recent years, electric vehicles are the large-scale spread of the transportation field has led to the emergence of brushless direct current (DC) motors (BLDCM), which are mostly utilized in electrical vehicle systems. The speed control of a BLDCM is a subsystem, consisting of torque, flux hysteresis comparators, and appropriate switching logic of an inverter. Due to the sudden load torque variation and improper switching pulse, the speed of the BLDCM is not maintained properly. In recent research, the BLDC current control method gives a better way to control the speed of the motor. Also, the rotor position information should be the need for feedback control of the power electronic converters to varying the appropriate pulse width modulation (PWM) of the inverter. The proposed optimization work controls the switching device to manage the power supply BLDCM. In this proposed self-ameliorate soft switching (SASS) system is a simple and effective way for BLDC motor current control technology, a proposed control strategy is intended to stabilize the speed of the BLDCM at different load torque conditions. The proposed SASS system method is analyzing hall-based sensor values continuously. The suggested model is simulated using the MATLAB Simulink tool, and the results reveal that the maximum steady-state error value achieved is 4.2, as well as a speedy recovery of the BLDCM's speed.

Soft-Switching System With Safe Connections of Capacitors and Inductors in Three-Phase Two-Level Voltage Source Inverter

This article presents a new soft-switching system for three-phase two-level voltage source inverters. In this system, capacitors are not connected in parallel to the main transistors, and inductors are not connected in series with the auxiliary transistors. Avoiding these types of connections protects the inverter transistors against damage in cases of disturbances in the inverter control system. The control algorithm of the main transistors of the inverter is the same as that of the transistors of an inverter operating with the hard-switching technique because the auxiliary transistors are switched depending on the operation state of the main transistors. The structure and operation principles of the new soft-switching solution are comprehensively described herein. Additionally, the control algorithm and the principles for selecting the elements of the new soft-switching circuits are discussed. The validity of the system operation was verified by performing laboratory tests with a three-phase voltage source inverter (3 kW, 250 V, 12 A, and 3 kHz) supplying an inductive-resistive load or a squirrel cage induction motor, whereas numerical calculations were performed for inverters with a higher rated power. The switching losses of the inverter operating with the proposed soft-switching solution were compared with those of an inverter operating with the hard-switching technique. The proposed soft-switching system increases the inverter efficiency, especially with medium- and high-rated powers.

Modifications of the soft switching system resistant to disturbances in control systems of voltage sources inverters

Czasopismo Techniczne » 2018 » Volume 10 » Modifications of the soft switching system resistant to disturbances in control systems of voltage sources inverters A A A

Control Global del Péndulo con Rueda de Reacción Empleado Redes Neuronales Artificiales y Linealización Extendida

En este artículo se presenta el diseño y la simulación de un controlador híbrido de dos etapas para el péndulo invertido con rueda de reacción (RWP). En la primera fase se realiza el modelado general del brazo pendular a través de un modelo no lineal que determina la energía almacenada en la planta, y usando una estrategia de balance conocida como regulación de energía (RE), se obtienen los datos necesarios para el entrenamiento de una red neuronal artificial (RNA). En la segunda etapa, por medio de un sistema de conmutación suave, se intercambia el control neuronal por un controlador basado en la linealización extendida de las variables de estado (LEVE), con lo cual se garantiza la permanencia del péndulo en la región de operación. La estrategia de control propuesta, muestra un excelente desempeño ante fenómenos de perturbación externa y garantiza la operatividad global del sistema físico.

소프트스위칭 방식을 적용한 절연형 승압용 DC/DC 컨버터

Recently, renewable energy sources are under the spotlight. due to the depletion of fossil fuels and environmental problem for the carbon dioxide. Among them, research on the Photovoltaic System using solar energy systems has been actively conducted. In this paper, we propose boosting the insulated DC/DC converter topologies Applied to soft-switching methods used in photovoltaic PCS. The proposed topology is of a type that combines a series of full-bridge converter and a boost converter, a full bridge converter and applying the insulation and soft switching system, the output voltage boost stage is carried out for the boost control. The proposed circuit validity was verified through the PSIM simulation and 5kW PV PCS Prototype and experiments.

Adaptive variable structure hierarchical fuzzy control for a class of high-order nonlinear dynamic systems

In this paper, a novel adaptive hierarchical fuzzy control system based on the variable structure control is developed for a class of SISO canonical nonlinear systems in the presence of bounded disturbances. It is assumed that nonlinear functions of the systems be completely unknown. Switching surfaces are incorporated into the hierarchical fuzzy control scheme to ensure the system stability. A fuzzy soft switching system decides the operation area of the hierarchical fuzzy control and variable structure control systems. All the nonlinearly appeared parameters of conclusion parts of fuzzy blocks located in different layers of the hierarchical fuzzy control system are adjusted through adaptation laws deduced from the defined Lyapunov function. The proposed hierarchical fuzzy control system reduces the number of rules and consequently the number of tunable parameters with respect to the ordinary fuzzy control system. Global boundedness of the overall adaptive system and the desired precision are achieved using the proposed adaptive control system. In this study, an adaptive hierarchical fuzzy system is used for two objectives; it can be as a function approximator or a control system based on an intelligent-classic approach. Three theorems are proven to investigate the stability of the nonlinear dynamic systems. The important point about the proposed theorems is that they can be applied not only to hierarchical fuzzy controllers with different structures of hierarchical fuzzy controller, but also to ordinary fuzzy controllers. Therefore, the proposed algorithm is more general. To show the effectiveness of the proposed method four systems (two mechanical, one mathematical and one chaotic) are considered in simulations. Simulation results demonstrate the validity, efficiency and feasibility of the proposed approach to control of nonlinear dynamic systems.

Design of an IDC Power Three-Phase Equilibrium Distribution Soft-Switching System

To decrease the cost brought by the electric energy waste, a three-phase equilibrium distribution soft-switching system is proposed. The system guarantees three-phase equilibrium. Firstly, the inverter tracks the original access phase to be synchronous, then switch the electric equipment to the inverter. Secondly, the inverter tracks the alternative access phase to be synchronous, then switch the electric equipment to the alternative access phase to accomplish the soft-switching. Experiment is used to carry out verification for this system. The result shows that there is no impulse current when the electric equipment switches. The system achieves soft-switching.

Design of a Balanced Three-Phase Power Supply Soft-Switching Based on Single-Phase Inverter Power

To eliminate the negative effects caused by three-phase unbalanced distribution, a novel soft-switching system based on single-phase inverter is proposed. The system achieves three-phase equilibrium distribution by adjusting the power supply of the electric equipments. This paper presents a track strategy named regulating frequency to promise no impulse current, which means regulating the output frequency of the inverter to make the output voltage of the inverter synchronize with the grid voltage. Firstly, make the output voltage of the inverter synchronize with the voltage of original access phase, then switch the electric equipment to the inverter. Secondly, make the output voltage of the inverter synchronize with the voltage of alternative access phase, then switch the electric equipment to the alternative access phase to accomplish the soft-switching. MATLAB software and experiment are used to carry out verification for this system. The result shows that the impulse current is practically zero when the electric equipments are switching. The system achieves soft-switching.

Full-bridge Converter의 새로운 ZVS 스위칭 기법

Existing switching system that is one of the ways which are used for DC/DC power converter is classified to hard-switching system and resonant-soft-switching system, generally. Hard-switching system is inefficient because the power loss of the switching element is large when it is been to trun on or turn off. And resonant-soft-switching system have the defect that need to add the another reactor and capacitor that make it expensive and huge. This paper suggest the ZVS Full-Bridge power converter contrcution of novel switching system for the overcoming these shortcomings. In Suggested soft-switching system, the front of buck converter at diode current, switch is changing on and off at the part of full-bridge converter`s zero voltage part. as the result that is possible to be ZVS excepting the reactor and capacitor. also to verify the reasonability of the isolated ZVS full-bridge DC/DC converter as previously suggested, we produced the 500[W] level DC/DC converter and enforced the simulation for Psim, and then it able to conform the superiority of the DC/DC converter`s efficient.

High-Power-Factor Soft-Switched DC Power Supply System

This paper proposes a dc power supply system to give high power factor and low current distortion on the rectifier side and provide stable dc voltage on the isolated dc/dc converter side. The proposed dc power supply system uses a new zero-voltage-switching (ZVS) strategy to get ZVS function. Besides operating at constant frequency, all semiconductor devices operate at soft switching without additional voltage stress. A significant reduction in the conduction losses is achieved, since the circulating current for the soft-switching flows only through the auxiliary circuit and a minimum number of switching devices are involved in the circulating current path, and the rectifier in the proposed dc power supply system uses a single converter instead of the conventional configuration composed of a four-diode front-end rectifier followed by a boost converter. An average-current-mode control is employed in proposed dc power supply system to detect the transition time and synthesize a suitable low harmonics sinusoidal waveform for the input current. A design example of 1000-W soft-switching single-phase dc power supply system is examined to assess the converter performance.

High-Efficiency•Low-Noise Resonant Three-phase Converter

In this paper, a soft switching system investigated on the 50 kVA medium capacity power supply system is reported. The main circuit is composed of a full bridge PWM converter/inverter connecting a capacitor in parallel to each main switch. The converter is provided with a commutation circuit for AC link resonance, while the inverter with a commutation circuit for DC link resonance respectively. Compared with the ordinary soft switching system, the proposed system has low part count. The commutation control circuit detects input current, output current and DC capacitor voltage to control commutation switches Q1-Q4 in a manner that commutation current can be minimized. As a result of experiments on the 50 kVA system, it was confirmed that the proposed circuit could reduce conduction noise below 10 MHz and improve the conversion efficiency from 88.5% to 90.5%, when compared with the hard switching circuit.