Papers by Keyword: Zero Voltage Switching (ZVS)

Abstract: This paper presents a combined asymmetrical voltage cancellation and pulse density modulation technique for energy efficient induction heating system. The proposed technique minimizes the switching losses through soft switching operation and improves the efficiency at low power level. In this modulation technique, the smooth power control can be achieved. The study of power converter has been performed through MATLAB simulation tool and the results are presented. In this proposal, the efficiency of PDM and AVC control techniques are compared with the Hybrid Modulation technique.

Abstract: The interest toward the application of fuel cells is increasing in the last years mainly due to the possibility of highly efficient decentralized clean energy generation. The output voltage of fuel-cell stacks is generally below 50 V. Consequently, low-power applications with high output voltage require a high gain for proper operation. A zero-voltage-switching (ZVS) dc–dc converter with high voltage gain is proposed for fuel cell as a front-end converter. It consists of a ZVS boost converter stage and a ZVS half-bridge converter stage and two stages are merged into a single stage. The ZVS boost converter stage provides a continuous input current and ZVS operation of the power switches. The ZVS half-bridge converter stage provides a high voltage gain. The principle of operation and system analysis are presented. Theoretical analysis and simulation result of the proposed converter were verified.

Abstract: —This The Pulse Width Modulation (PWM) DC-to-AC inverter has been widely used in many applications due to its circuit simplicity and rugged control scheme. It is however driven by a hard-switching pulse width modulation (PWM) inverter, which has low switching frequency, high switching loss, high electro-magnetic interference (EMI), high acoustic noise and low efficiency, etc. To solve these problems of the hard-switching inverter, many soft-switching inverters have been designed in the past. Unfortunately, high device voltage stress, large dc link voltage ripples, complex control scheme and so on are noticed in the existing soft-switching inverters. This proposed work overcomes the above problems with simple circuit topology and all switches work in zero-voltage switching condition. Comparative analysis between conventional open loop, PI and fuzzy logic based soft switching inverter is also presented and discussed. Keywords— Zero voltage switching, Inverter, Dc link, PI controller, Fuzzy logic system control ,Modulation strategy, Soft switching

Abstract: This paper presents a Hardware implementation of single-stage solar based DC-DC converter for inductive load application. Solar model is connected in the input side. The circuit has two full wave converter connected to boost the voltage and also for the power factor correction. Switch-utilization factor is improved by using two active switches to serve in the PFC circuits. Controlled converter is used to load side along with pi filter. Finally inductive load is connected to output side. In the hardware circuit solar panel output voltage, transformer primary, secondary voltage and load voltage is measured. In the circuit used with all the component parameters to operate at zero-voltage switching which retains the high circuit efficiency. A circuit is designed for an 80v dc output and tested.

Abstract: This paper discusses the design and simulation of pulse width modulated based circuit for induction melting application. This high frequency inverter topology have the practical advantages of energy saving, clean environment, high output power due to low switching losses, less electromagnetic noise and low total harmonic distortion. This two stage power converter has single phase full bridge rectifier, DC filter, zero voltage switching pulse width modulation controlled high frequency inverter. In this work, the steady state operation and control strategy of pulse width modulated high frequency inverter is analyzed. In order to achieve energy efficiency switching losses are reduced by operating the inverter above resonance frequency. Input side supply harmonics is also reduced using EMI filter. The simulation of the designed high frequency power supply is carried out at a frequency of 20 kHz using MATLAB simulink tool. Simulation results proof the energy saving due to reduction in switching losses of the presented control strategy and reduction in harmonic distortion of the presented power supply for induction heating load.

Abstract: This paper analyses the characteristics of parallel LLC resonant converter, and makes the comparison of the characteristics of the order switch shunt and staggered parallel switch circumstances converter. The circuit uses UC3863 chip as the core control chip switch power supply, circuit adopts the half bridge structure. This model is seldom put forward through the experiments prove the feasibility and practicability of the LLC, and greatly improving the working efficiency. Using SABER simulation software for the converter circuit simulation and analysis with the theoretical calculation of the device parameters. Example of 300v voltage input, 12-18v output voltage, 2.5 KW, 500 KHZ parallel LLC resonant converter design and simulation for model analysis. Sum up the advantages of the parallel LLC resonant converter compared with the traditional LLC resonant converter .The results of simulation verify the feasibility of the design and the accuracy of the conclusion.

Abstract: This paper proposes a new improved zero-voltage switching isolated boost converter with coupling inductors. With the traditional advantages of smaller input current ripple, low diode voltage rating, and low transformer turns ratio of boost half bridge topology [ being retained, the proposed converter makes it much easier to realize zero voltage switching of primary switches compared with conventional converters.

Abstract: Based on the need to develop and test the products, a single phase DSP­based programmable AC power supply is designed. The power supply is capable of providing a stable AC voltage with adjustable amplitude and frequency over a wide range. Moreover, it can generate various high quality and low frequency arbitrary waveforms. Because of the advantages above, it will have great value in practice and a promising future in testing field. The main circuit of the power supply is to use rectifier and filter to make 220V AC voltage become steady DC voltage firstly. Then the inverter and the LC LPF are employed to produce the AC voltage which is required in the test system. The key part of the inverter is phase shift full bridge.

Abstract: In this research, a high-voltage direct current zero voltage switching (ZVS) PWM half-bridge converter is proposed. The parameters of the converter as follows: the input voltage is up to 4000V;the output voltage is 600V.The new ZVS PWM TL converter has neutral point clamping diodes and flying capacitor. This research is going to analyze the working principle of circuit witch thus realizing the zero voltage switching and the circuit parameters selection. Moreover, circuits simulation is carried out by MATLAB to verify the reliability and feasibility of this DC/DC converter topology.

Abstract: In this paper it constructs a phase shift to control zero-voltage-switching of high frequency inverter spot welding power supply topology structure. Through testing the former vice edge current, the system realizes the closed loop control. In this paper, it shows the working condition of main circuit modal. The experimental results proved the advantages of the topological structure.