Category Archives: MatLab Projects
This paper presents a novel four-level hybrid-clamped converter topology which is composed of eight switches and one flying capacitor per phase. The operating principle is introduced and phase-shifted pulse width modulation is used to control this converter. A detailed analysis of the average currents through the flying capacitor and neutral points of the dc-link is presented. Based on the analysis, it can be concluded that the voltages across the flying capacitor and dc-link capacitors can be naturally balanced under ideal and steady-state condition. A low-power three-phase prototype is built up and experimental results are presented to validate the proposed topology and modulation method.
A novel multiport isolated bidirectional dc-dc converter for hybrid battery and supercapacitor applications is presented, which can achieve zero voltage switching for all switches in the whole load range. The bidirectional power flow between any two of the ports is free, and the circulating power is low for the well matching of the transformer voltages of all time regardless of the voltage variations of the battery and supercapacitor. Moreover, the current ripples are greatly decreased by interleaved control, which is good for battery and supercapacitor. The converter topology and the operation principle are introduced. Detailed analysis on soft-switching of all switches is given. On the basis of theoretical analysis, the principle and method for parameter designing are provided. A hybrid energy management strategy combining bus voltage control and energy management of the energy storage devices is proposed and the control scheme is presented. Moreover, detailed parameter design of a prototype converter is given for a 380-V dc-bus microgrid lab system. Effectiveness of the control strategy, correctness of the analysis on soft-switching, and the parameter design methods are verified by the simulation and experimental results.
This paper proposes a zero voltage switching (ZVS) technique for bidirectional dc/dc converters. The dc/dc unit considered consists of two distinct bidirectional dc/dc cells paralleled at both input and output and whose two input bridges are coupled by means of passive inductive branches. A multiangle phase-shift modulation method is proposed which simultaneously achieves bidirectional power control, power sharing, and ZVS of all the electronic devices over the full power range without the need for auxiliary switches. Simulation and experimental results are reported for a 2.4 kW dc/dc unit consisting of two paralleled 1.2 kW bidirectional dual-bridge series resonant converter cells.
Voltage-source converter (VSC)-based transmission systems have attractive potential features in terms of power flow control and stability of the network. Although relatively low switching frequency operation of high-power converters (9-15 times the line frequency) is desirable, it makes them sensitive to power network imbalances when they may be needed the most.
This paper presents a sliding mode controller to address the problem of voltage regulation in microgrids involving doubly fed induction wind generators (DFIGs). The control objective is to achieve terminal voltage regulation while ensuring maximum power point tracking (MPPT). The control development is based on voltage sensitivity analysis to eliminate the possibility of interference with the other voltage regulation devices in the microgrid. The proposed method:
This study presents a modified flying capacitor three-level buck dc-dc converter with improved dynamic response. First, the limitations in the transient response improvement of the conventional and three-level buck converters are discussed. Then, the three-level buck converter is modified in a way that it would benefit from a faster dynamic during sudden changes in the load. Finally, a controller is proposed that detects load transients and responds appropriately.
High-Efficiency Digital-Controlled Interleaved Power Converter for High-Power PEM Fuel-Cell Applications
A high-efficiency digital-controlled interleaved dc-dc converter is designed and implemented to provide a regulated high voltage output for high-power proton-exchange-membrane fuel-cell applications. Ripple cancellation on input current and output voltage can be achieved by the studied interleaved dc-dc power conversion technique to reduce hysteresis energy losses inside the fuel-cell stacks and meet battery charging considerations on the high-voltage dc bus.
This paper proposes a high-efficiency dc-dc converter with fast dynamic response for low-voltage photovoltaic (PV) sources. The voltage stress of power switches is reduced at low-voltage side. Zero-current turn-off of output diodes is achieved at high-voltage side. Power efficiency is improved by reducing switching power losses. A modified proportional and integral controller is also suggested to achieve fast output voltage control.
Photovoltaic (PV) systems proposes attractive alternative source of generation because these can be placed near to the load centers when compared with other renewable source of generation. It is therefore rooftop PV is the centre of attraction for majority PV systems. The rooftop PV system in general is grid connected and supports the off grid load with battery backup. The designed system must ensure total evacuation of generated power and with high efficiency of conversion, and utilizes the resource adequately to maximize the utilization of energy.
Design, analysis and simulation of linear controller of a STATCOM for reactive power compensation on variation of DC link voltage
The STATCOM (STATic synchronous COMpensator) is a shunt connected voltage source converter using self-commutating device and can be effectively used for reactive power control. Its principle of operation is similar to that of a synchronous condenser. This paper describes the modeling of STATCOM along with the design of linear current and voltage controllers. The design of controllers for the converters can be realized in two ways.