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This paper proposes a unified algorithm for PWM strategies of matrix converters. A general form of the modulation functions for the matrix converter is derived based on the geometric transformation approach. The research results reveal that each allowable modulation matrix can be expressed as an indirect modulation. Moreover, this paper presents a new viewpoint to consider the matrix converter as...
The paper presents results of analysis of operation of asymmetrical split-phase (six-phase) electric vehicle drive on the base of two neutral-clamped converters, controlled by combined schemes of synchronized pulsewidth modulation (PWM), providing both common-mode voltage cancellation and continuous synchronization of the output voltage of inverters during the whole control diapason. Simulations give...
The paper presents results of dissemination of a novel method of synchronized pulsewidth modulation (PWM) for control of dual (cascaded) neutral-point-clamped inverters for photovoltaic generation. Basic system topology includes two insulated strings of photovoltaic panels, feeding two cascaded neutral-clamped inverters, connected to grid by a three-phase transformer with the open winding configuration...
This paper presents an improved topology of BLDC motor drive with a DC-DC Converter in the DC link and a combined Pulse Amplitude Modulation (PAM) and Pulse Width Modulation (PWM) technique. The goal is to separate the speed control and inverter commutation, in order to reduce switching losses and the inverter size and cost. Digital simulations of the proposed drive are performed with position sensors...
This paper proposes to apply an AC/AC direct converter topology for servo systems. In the conventional AC/AC converter which consists of a PWM rectifier and a PWM inverter, the p-n junction temperature becomes high at the low output frequency or the servo-lock operation because the output current concentrates at the specific switching devices in the inverter. On the other hands, the AC/AC direct converter...
Operation of switch-mode converters results in electromagnetic noise propagating throughout the power electronic system. PWM strategies with fixed switching frequency generate harmonics in the spectra of converter voltages and currents. Random pulse width modulation techniques allow elimination of the harmonics, resulting in a continuous spectrum of noise, that is, a spectrum retaining all frequency...
Interleaving PWM waveforms is a proven method to reduce ripple in dc-dc converters. The present work explores interleaving for three-phase motor drives. Fourier analysis shows that interleaving the carriers in conventional uniform PWM significantly reduces the common-mode voltage. New DSP hardware supports interleaving directly with changes to just two registers at setup time, so no additional computation...
A novel hybrid cascade H-bridge converter is presented in which cascaded H-bridge cells and one three-phase two-level converter with a flying capacitor are connected together. The output voltage will be increased while the number of isolated DC bus can be reduced. PWM control method and flying capacitor voltage balancing algorithm are analyzed. Simulation results verified the proposed performance.
A power electronics circuit is a converter that converts energy from one level of voltage/current/frequency to another using semiconductor-based electronic switches. The process of switching the electronic devices in a power electronic converter from one state to another is called modulation. There are a number of modulation strategies. The less the degree to which undesirable harmonics are created...
Pulse-width modulation (PWM) of a signal or power source involves the modulation of its duty cycle, to either convey information over a communications channel or control the amount of power sent to a load. This paper presents work on modelling and simulation of modified unipolar PWM applied to a single phase DC-AC converter (inverter) as switching control schemes. The harmonic analysis for switching...
This paper presents a feasibility study of a zero voltage switching (ZVS) PWM dual full bridge (DFB) DC-DC converter with secondary-side phase-shifting power control scheme. The soft-switching PWM DC-DC converter newly-developed for a DC pre-voltage regulator in a plasma radiofrequency (RF) power generator can achieve soft commutation at all the power devices under the wide range of load power. By...
This paper deals with a new circuit prototype of two active edge resonant cells-assisted soft-switching symmetrical PWM half-bridge inverter type DC-DC high power converter employing a high frequency planar transformer with center-tapped secondary windings and rectifier with choke-input. Its operating principle is described in detail by using switching mode transition equivalent circuits which is...
A general problem in the double PWM converter is the voltage unbalance of the dc-link capacitors. This unbalance distorts the waveforms of the output voltage and current. Furthermore, it will lead to instability of the inverter system. Based on the analysis for the unbalance problem, a novel feedback control strategy of DC capacitor voltage deviation is proposed in this paper. The method does not...
Many countries are making strong harmonic current regulations for high power consuming equipments to reduce power loss and voltage distortion in power distribution. To comply with the regulation, the PWM converter is receiving more interest due to the low harmonic current generation compared with diode rectifier and unity power factor. This paper introduces a design of PWM converter inverter system...
This paper presents an analysis and the design of an off grid PV system for providing electricity for remote area. The system composed of dc-dc multilevel boost converter (MLBC) which is used for extracting maximum power from the cell. It has been chosen to generate three dc voltages at its output terminal. In addition to, a multilevel dc link inverter suitable for the generated dc bus voltages. The...
This work analyzes the proportional (P) and the proportional-integral (PI) control strategies of current loop controllers applied to pulse width modulated (PWM) power converters. Maximum and minimum gain limits are established for both cases based on the converter per-unit (pu) values. The drawbacks of each controller, for the operation in continuous time domain, are also evaluated.
An accurate theory of calculating the DC link capacitor voltage ripple and current ripple for SPWM inverters and PWM rectifiers, which are most commonly used in series hybrid electric bus (SHEB) converter/inverter systems at low speed, is presented in the paper. Most of all, the results are analyzed and summarized into graphs, which helps to find the right capacitance value for a given voltage ripple...
In this paper, a hybrid cascade multilevel three-phase converter is constructed based on field programmable gate array (FPGA). FPGA comprises thousands of logic gates and it provides flexibility to modify the designed circuit without altering the hardware. So FPGA is applied to design the PWM pulse generator for multilevel converter with no synchronization and communication trouble. A SHPWM pulse...
This paper presents the implementation and experimental results of an algebraic real-time sinusoidal pulse width modulation algorithm (SPWM) based on B-Spline carriers. B-spline functions are used as carrier signals with the aim to to reduce harmonic content of the three phase inverter output voltage. The presented algorithm eliminates the problem of B-spline recursive evaluation with convolution...
A novel method of synchronized pulsewidth modulation (PWM) has been disseminated for control of dual neutral-point-clamped inverters feeding asymmetrical dual three-phase (six-phase) motor drive with two DC sources. Control algorithms provide in this case elimination of alternating common-mode voltages both in each inverter and in the load. Phase voltages of the drive system are characterised by quarter-wave...
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