Phase PWM Research Articles

Closed-Loop Harmonic Suppression for Grid Connected 3-Phase PWM Inverters

Closed-Loop Harmonic Suppression for Grid Connected 3-Phase PWM Inverters

Single Phase Inverter Design for Solar Panel Output Voltage

Inverter is a devices that functions to convert DC input voltage to AC. One technique for optimizing the inveter output is SPWM. In this final project, a single–phase SPWM inverter with bipolar SPWM switching is designed. This inverter has 1 phase H-Bridge spesifications, with IGBT components, resistors, warehouse and inductors where there are 4 MOSFETs that can be connected. By carrying out 3 test with different sources for a 244.44 volt DC source it produces 0,47 % harmonic, a variable DC source produces 54,81 % harmonics and for a PV sources 9,91 % harmonics. Of the three test, the largest harmonic value is by using a variable DC source. Large harmonic can affect the shape of the wave to be non-sine and the wave has lots of ripples. This simulation aims to facilitate the design of real inverter devices.

Maximum Power Control of DFIG Based Grid Connected Wind Turbine Generator System

This paper presents a simulation model of variable speed wind turbine with a doubly fed induction generator developed in Matlab/simulink. Vector control of a doubly fed induction generator (DFIG) drive for variable speed wind power generation is described. A slip ring (wound rotor) induction generator with back to back three phase PWM converter between its rotor and the grid forms the electrical system. A vector control scheme for the PWM converters results in independent control of active and reactive power. Line (supply) voltage oriented reference frame has been used to independently control the active and reactive power. Results are provided at the end for sub synchronous and super-synchronous operation of the DFIG.

Optimization of Single-phase PWM Rectifier Performance by Using the Genetic Algorithm

This paper is dealing with single phase PWM rectifier parameter optimization. A control loop has been designed to attain a suitable output DC voltage with minimum ripple, input current with minimum harmonic and maximum input power factor. In this paper these parameters have been optimized by using Genetic algorithm. To verify the effectiveness of proposed optimization, different simulations have been done. By using MATLAB simulink the simulation results prove that the proposed system working good.

Highly-Efficient Power-Conditioning System for Grid-Tied Fuel Cell Power Generation

ssssssssThis paper proposes a grid-tied power conditioning system for the fuel cell power generation, which consists of a 2- stage DC-DC converter and a 3-phase PWM inverter. The 2- stage DC-DC converter boosts the fuel cell stack voltage of 26- 48V up to 400V, using the hard-switching boost converter and the high-frequency unregulated LLC resonant converter. A laboratory experimental set-up was built with the 1.2kW PEM fuel-cell stack to verify the feasibility of hardware implementation. The developed power conditioning system shows high efficiency of 91%, which is very positive result for the commercialization. ssssss

Proper magnetic materials selection method for AC filter inductor design used in single phase PWM inverters

The use of wide-bandgap devices such as SiC and GaN has improved the efficiency and power density of power converters compared with conventional Si devices. However, a significant portion of the efficiency loss and volume in power converters is attributed to the magnetic components, particularly the challenges of miniaturization and loss reduction. This is due to the use of nonsinusoidal waveforms, with high-frequency switching of the PWM inverter introducing ripple components that exhibit complex loss characteristics. In this study, we propose a method for selecting magnetic materials for AC filter inductors based on loss and volume considerations. In addition, the effectiveness of the proposed method is validated through experiments.

Performance Evaluation of Induction Motor Behaviour on Conventional and PV System Power Sources

The present study explores the integration of photovoltaic (PV) systems for enhancement of power system quality and reliability, particularly when PV system is deployed to power inductive loads which have wide applications in commercial and industrial settings. A mixed approach is deployed using MATLAB/Simulink for the modelling and simulation process. The study investigates the impact of inductive loads on PV system, comparing its performance with a conventional power source of same power willing capacity. The PV system was modelled by connecting PV arrays in series and parallel combinations. The output of the PV arrays was fed into a three phase PWM inverter, the harmonics present at the inverter output were eliminated using properly sized Inductor- capacitor (L-C) filter circuit. Also, a three-phase conventional source of same output capacity was modelled. Comparative analysis of the impacts inductive loads has on both sources were carried out and this was accomplished by integrating three-phase asynchronous motor rated at 15kW(20HP). The induction motors were independently powered by two distinct sources and further subjected to intermittent loading conditions. The major parameters investigated includes the rotor speed, rotor current, and electromagnetic torque of the asynchronous motor. The outcome of the study showed that the conventional source outperforms the PV system. These necessitates the studies on adoption of advance strategies on how the negative impacts and challenges encountered in the course of integrating PV system to power inductive loads will be address.

Grid Integration of Livestock Biogas Using Self-Excited Induction Generator and Spark-Ignition Engine

This study developed a grid-connected biogas power generation system for a rural community using a 3-phase 2.2 kW squirrel-cage induction machine as the self-excited induction generator. The generator was driven by a 196 cc single-cylinder spark-ignition engine fueled by biogas. We developed a back-to-back converter that consists of a 3-phase PWM rectifier as the generator-side converter and a single-phase LCL-filtered grid-connected inverter. The generator-side converter transferred the active power to the grid-side converter and supplied the reactive power control back to the generator. The notch filter-based bus voltage control on the generator side mitigated the inter-harmonics in the generator current. The injected grid current complied with the IEEE 1547 standard because of the multi-frequency unbalanced synchronous reference frame control. The proposed system was validated with biogas produced from pig manure at a pig farm in central Thailand, which found a maximum output of 1.2 kW with a thermal system efficiency of 10.7%. The proposed system was scheduled to operate at 1.2 kW for 8 h per day with a levelized cost of 0.07 US$/kWh, 42% cheaper than the retail electricity price, and a payback period of 2.76 years. The proposed system is suitable for a farm with a minimum of 34 pigs.

A control approach for power quality improvement of a large-scale grid connected PV system at standard test conditions

In this paper two stage grid connected photovoltaic system (GCPVS) is simulated in MATLAB/Simulink software with control strategy based on voltage source converter (VSC) which is operated to supply active power and filter the harmonics currents at common coupling point (CCP). The developed control scheme is applied to a large- capacity system of 1 MW and the parameters of the system components are attuned to achieve harmonics level in accordance with the IEEE standard 519. In presented system, power electronic converters, boost converter and inverter, are interfaced between photovoltaic generation unite and grid. To maximize power delivery by photovoltaic system, perturb and observation algorithm based maximum power point tracking technique (MPPT) is used for boost converter control. For the inverter control, VSC based strategy including reference frame transformation, phase lock loop interface, PI controllers and PWM technique is applied. The system performance was evaluated for power and voltage control at standard test conditions (STC) and relevant IEEE standard has been considered for its validation. Moreover, harmonics level for voltage and current signals at CCP is monitored by Fast Fourier transformation (FFT) analysis. Simulation results are presented to verify system performance for selected parameters.

Switching loss analysis of IGBT and MOSFET in single phase PWM inverter fed from photovoltaic energy sources for smart cities

Switching loss analysis of IGBT and MOSFET in single phase PWM inverter fed from photovoltaic energy sources for smart cities

Performance Benchmarking of Active-Front-End Rectifier Topologies Used in High-Power, High-Voltage Onboard EV Chargers

High power onboard battery chargers employed in electric vehicles (EVs) and plug-in hybrid EVs (PHEVs) fed from three-phase mains typically consist of a two-stage structure as AC-DC and DC-DC stages. The AC-DC stage is also known as the active front end (AFE). While the AFE rectifies the mains voltage, maintains the power factor, and provides a constant DC-link voltage to the DC-DC converter, the DC-DC converter stage regulates the charging current considering the charging algorithms in order to extend the battery service life. This study focuses on the selection of cost/performance effective AFE topology that can be used in high power onboard chargers. Four different suitable AC-DC topologies are investigated: (i) 3-phase 2-level rectifier, (ii) 3-phase, 3-level neutral-point-clamped (NPC) rectifier, (iii) 3-phase, 3-level T-type rectifier, and (iv) Vienna rectifier. In this study, the aforementioned AFE topologies have been simulated on the PLECS/SpeedFit environment and compared in terms of efficiency, losses, temperature, the number of switching elements, cost and cost/efficiency metrics. The performance results of the aforementioned topologies have been evaluated under different operating frequencies. The results reveal that the most suitable topology alternatives for the front-end AC-DC converter are 3-phase 2-level PWM rectifier and Vienna rectifier. Although the 3-phase 2-level PWM rectifier is superior with its 12% cost advantage, fewer components, and ease of control advantages, it lags a little behind the Vienna rectifier in terms of total harmonic distortion.

Comparative study of control techniques for three phase PWM rectifier

This paper studies and compare the performances of different control strategies of 3-phase active rectifier under different load and frequency conditions. There are three main control approaches to be investigated such as: Voltage Oriented Control (VOC), Direct Power Control (DPC) and Model Predictive Control (MPC). The traditional method VOC has been used widely in practice. Its control principle is available to many different grid-connected converter systems such as electric drive system, renewable energy conversion system. However, the problem of optimal design of the current regulators for the different operating conditions of the system is not an easy problem. The DPC and MPC methods then help to eliminate the disadvantages of the VOC. The MPC method has been now become much interesting since it offers a general solution to a multi-goal optimization problem. In the paper, the system structures and controller parameters are briefly presented. The main evaluation factors of the active rectifier are low input current distortion (THD), a unit input power factor and stable DC output voltage. Three methods are analyzed and verified using MATLAB software and measuring experiment on a real model. The obtained results show that the VOC method achieves stable quality under different load as well as the switching frequency conditions, while the MPC method may achieve good quality with a rather high switching frequency.

Simulation model of single phase PWM inverter by using MATLAB/Simulink

This work is presenting under the title simulation model of single phase PWM inverter by using MATLAB/Simulink. There are many researchers’ works in this field with the different ways because it is important field and it has many applications. The converter DC power to AC power for any system that mean it need the power electronic device (inverter). The inverter is using when the source DC power and the load AC power. In this work, the simulation system includes the source 300V DC power, inverter, LC filter and load (R). The simulation result shows the waveform of all part in this system like input and output current and voltage.

Research of Three Phase PWM Rectifier based on Direct Vector Control Method

In oilfield worldwide, beam pumping units are wildly used to produce oil. the working mechanism of beam pumping unit determines that its driving motor frequently enters into the state of power generation, so PWM reversible rectifier is an ideal choice for recycle the generated energy, therefore it is necessary to research the control theory of PWM reversible rectifier. The paper presents a digital algorithm for the PWM rectifier, on the basis of coordinate analyzing theory and SVPWM method. The method that directly calculates the basic vector operation time and position is adopted, so the arc-tangent calculation is avoided, calculation process is simplified. Based on the vector coordinate transformation of three-phase reversible PWM rectifier, the control equation of direct current control method is derived in this paper. The rectifier control algorithm is realized with high performance DSP TMS320F28335. The experimental results prove that the method proposed in the paper is practical and correct.

Dual loop control for single phase PWM inverter for distributed generation

Abstract In this paper the design of synchronous frame DQ control based double loop control for single phase inverter in distributed generation system is proposed. For synchronous frame control, the orthogonal signal is generated by second order generalized integrator method. In Dual-loop control systems, the inner capacitor current feedback control and outer synchronous frame control is used to achieve better performance with zero steady state error. The better performance of load is achieved by providing load current as an additional feedback instead of using inductor current feedback. The proposed system is simulated using Matlab and results were presented. The designed controller gives the inverter output voltage with good transient response and reduced harmonic distortion.

Research on multi-core DSP cooperative control system in environmental protection equipment

Traditional multi-servo motor control systems have the problems of poor output stability in environmental protection equipment, weak robustness, and low control ability. Based on this, the research of multi-servo motors control systems based on FPGA are proposed. The paper Construct a parameter distribution models on multi-servo motor control, using motor terminal voltage, current, and back-EMF as control constraints, calculate the difference between the output currents of the multi-servo motors, and construct a saturation function to analyze the multi-servo motor control objective function. Sampling phase current signal and PWM duty cycle as modulation parameters, combined with fuzzy adaptive PID control method to control the output robustness of multiple servo motors, calculating the equivalent mechanical power and equivalent electromagnetic power of multiple servo motors. The optimized parameter adjustment method performs self-tuning processing of the motor output, and the transient stability adjustment of the multi-servo motor is performed based on the method of the average terminal voltage analysis to realize the optimal design of the multi-servo motor control law. The test results show that the output stability of the output of the multi-servo motor control system using this method is better, the motor control is more robust and the control ability is higher.

Positive and Negative Sequence Voltage Compensation Using Statcom at Wind Farm

The study of shunt connected FACTS devices is a connected field with the problem of positive and negative voltage compensation and better mitigation of instability problems in today’s world. In this project, the shunt operation of FACTS controller is studied, the STATCOM, and how it helps in the better utilization of a network operating under normal conditions. First literature review of many papers related to FACTS and STATCOM is carried out, along with positive and negative voltage compensation. The study of STATCOM and its principles of operation and control, including phase angle control and PWM techniques, are carried out. The study of shunt connected devices is a shunt connected field positive and negative sequence voltage compensation and better mitigation of transmission related world. Statcom is a FACTS device whose capacitive or inductive current can be controlled independent of system ac voltage. Whenever an asymmetrical fault occurs in a system, power loss and voltage instability can occur in that system. So to increase the life time of generator drives and to reduce that voltage instability, Statcom can be used. Statcom can compensate positive sequence voltage for improving voltage stability and for reducing torque ripples negative sequence voltage has to be compensated. Statcom can perform co-ordinated action regarding positive and negative voltage compensation. In this thesis, review of positive and negative voltage compensation and results for positive sequence voltage compensation and negative voltage compensation using MATLAB simulation is shown.

Design and Implementation of Fuzzy Logic based Single Phase Inverter using FPGA Controller

The single phase inverter provides continuous AC power supplies without any interrupt .The idea is to serve sinusoidal AC output whose voltage and frequency can be controlled by PWM pulse. The main theme of this concept is to present a new construction of an FPGA based control techniques for inverter. In this proposed system, a PI controller is used to the single phase PWM voltage source inverter. It minimizes periodic distraction resulted from linear load. Simulation provides the results, with reduced harmonics distortion of the output voltage .and innovative technique for including a fuzzy logic controller through a usual sampled pulse-width modulator is reported. The FLC is used to decrease the harmonic distortion and to offer better standard regulation. Simulations are carried out in ALTERA-Quartus II 8.0 software in addition by means of Matlab/Simulink and the results are presented for various control techniques. FPGA controller is preferred for the real time realization of the switching approach, for the most part owing to its larger computation speed which is able to guarantee the precision of the PWM pulse is developed. At the concluding stage the FPGA is used as a PWM generator in order to apply the appropriate signals for inverter switches

Experimental Verification of Deadbeat Control with 1-MHz Multisampling and Disturbance Compensation Method for Three Phase PWM Inverter

Experimental Verification of Deadbeat Control with 1-MHz Multisampling and Disturbance Compensation Method for Three Phase PWM Inverter

Improved virtual flux direct power control of three phase PWM rectifier using SOGI-FLL estimator under disturbed voltage conditions

In this paper, improved sonsorless direct power control (DPC) of three-phase rectifiers is presented. The new system are based on virtual flux (VF) and notch filter using Second Order Generalized Integrator frequency located loop SOGI-FLL estimator. In order to improve the VF-DPC performance of PWM rectifier, an improved observation method of virtual flux-linkage is proposed. To avoid the relevant problems of pure integrator, and to achieve the accurate observation of the grid voltage’s phase, (SOGI-FLL) are used to displace the pure integrator. Theoretical principles of this method are presented and discussed. These strategies are also investigated under disturbed grid voltage. A theoretical analysis of active and reactive power under a non-ideal source is clearly demonstrated. In order to calculate the compensated powers, the extraction of positive, negative, and harmonic sequences of voltage and current is needed and a multiple dual SOGI-FLL method is used for rapid and accurate extraction. It is shown that the VFDPC with integrating notch filter exhibits several advantages, particularly providing small ripple of DC-link voltage and sinusoidal line current when the supply voltage is not ideal.