Phase PWM Inverter Research Articles

Voltage Error Estimation-Based Fault Diagnosis Method for Three- phase PWM-inverter in Grid-connected Photovoltaic Power System Without any Over-rating

Inverter is an essential component of a grid connected PV system. In fact, an open-switch fault in this power converter could result an important system malfunction and consequently leads to system disconnection. In this context, this paper focuses on the fault-tolerant control of PWM-inverter with redundancy leg for grid-connected PV system. In addition, a fast method of fault detection and compensation is used to maintain the continuous operation of the converter when there is a half-leg open-circuit fault (IGBT+ anti-parallel diode) on one of PWM-inverter legs. Therefore, it can detect this type of fault and compensate it in less than 50 μs by using a time criterion instead of voltage criterion. Also, the fuzzy logic technique is employed to control the active and reactive power injected into the network without exceeding the whole system power capacity limits. Note that, in this study, the active and reactive power references of the chosen operating point (the reactive-to-active power ratio: tgφ = Q/P = 0.19) are based on experimental tests. Simulation results show the feasibility and the effectiveness of the proposed fault diagnosis method in terms of fault detection and service continuity in presence of a half-leg open-circuit fault in PWM-inverter without any over-rating of the PV system components or instability.

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.

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

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.

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.

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

Effects of Modulation Index on Harmonics of SP-PWM Inverter Supplying Universal Motor

This manuscript presents the effects of changing modulation indices on current and voltage harmonics of universal motor when it is supplied by single phase PWM (SP-PWM) inverter, the effect has been analyzed with simulation and experimental setup. For variable speed applications universal motor can be controlled either by phase angle control drive or by SP-PWM inverter drive. SP-PWM inverter-fed drive is common technique that is used to adjust the voltage applied to motor, so that variable speed can be obtained. With the application of SP-PWM inverter-fed drive, harmonics are generated because of power electronic devices. According to the IEEE standard 519, the total harmonic distortion (THD) must be within 5%. In this paper, the effect of modulation index (MI) is used to analyze THD content, and its variation alters the harmonic content. However, the effects are also analyzed through experimental setup in order to validate the system performance. In future work, keeping modulation index constant, different PWM strategies can be employed in order to decrease harmonics.

A Galvanic-Isolated Grid-Connected fuel cell single phase AC power generation system with LCL filter

Fuel cell system is a promising alternate way of power generation from clean, green fuel such as Hydrogen with almost zero emissions. It can be a primary power or an aiding power to the grid during instability. Grid connected fuel cell systems experience double line frequency ripples from the inverters which affect the life of fuel cells. The current ripples are to be limited within 15% for safe operation of the fuel cells. This paper presents design of a dual active bridge DC-DC converter to step up the low voltage DC output from fuel cell to a high voltage DC with galvanic isolation and a PLL based grid synchronized single phase PWM inverter with dq reference frame grid current control suitable for fuel cell systems. Extended Symmetrical Optimum method is used for optimal tuning of the PI controllers. An LCL filter is designed for effective ripple attenuation in the grid current with active damping of the resonance in the region of stability. MATLAB/Simulink ® is used for the design and is verified with a 1kW Horizon PEM fuel cell system. The power is exported to the grid with measured THD i of 1.7% in the grid current with reactive power injection by simple phase shift modulation control. The maximum overall system efficiency is measured to be 85%.

불연속 변조 기법을 이용한 고속철도 추진제어장치용 단상 PWM 컨버터

본 논문에서는 불연속 변조 기법을 이용한 고속철도 추진제어장치용 단상 PWM 컨버터에 대해 연구하였다. 기존 PWM 컨버터는 대 전력 특성으로 인해 스위칭 손실을 줄이기 위해 주파수 변조지수를 10 이하로 낮게 사용함에 따라 제어의 대역폭이 감소하고, 안정적인 역률 제어를 위해 추가의 보상 기법을 필요로 하는 등의 문제점을 가지고 있다. 이를 해결하기 위해 3상 PWM 인버터에서 사용하는 불연속 변조 기법을 단상 PWM 컨버터에 적용하였다. 제안한 방식은 옵셋 전압 기법을 활용하여 간단히 구현될 수 있으며 동일 스위칭 손실 대비 주파수 변조 지수를 2배 증가시켜 제어 특성을 향상시키고 스위치 간의 동특성도 동일하게 가져갈 수 있다. 100 kW급 PWM 컨버터에 대한 시뮬레이션을 통해 제안한 불연속 변조 기법에 대한 타당성을 검증하였다. In this paper, for high speed railway propulsion systems, a single phase PWM Converter using discontinuous PWM (DPWM) was investigated. The conventional PWM Converter uses a low frequency modulation index of less than 10 to reduce switching losses due to high power characteristics, which results in low control frequency bandwidth and requires an additional compensation method. To solve these problems, the DPWM method, which is commonly used in three phase PWM Inverters, was adopted to a single phase PWM Converter. The proposed method was easily implemented using offset voltage techniques. Method can improve the control performance by doubling the frequency modulation index for the same switching loss, and can also bring the same dynamic characteristics among switches. Proposed DPWM method was verified by simulation of 100 kW PWM converter.

A Variable Switching Frequency Approach to Reduce the Output Current Ripple of Single -Phase PWM Inverters

A Variable Switching Frequency Approach to Reduce the Output Current Ripple of Single -Phase PWM Inverters

Short-Circuit Incipient Faults Detection from Single Phase PWM Inverter using Artificial Neural Network

Solar Photovoltaic (PV) system consists of three main parts which are PV array, PV inverter and utility grid. From the three, PV inverter is considered the weakest link in the solar PV system. Insulated Gate Bipolar Transistor (IGBT) is the most critical component in an inverter and is often blamed for the failure of inverters. If the incipient faults of the IGBT can be detected, the breakdown possibility of the solar PV system can be improved. However, before the incipient faults can be detected, it needs to be first generated before further analysis and improvements can be made. This paper proposes a process on how to generate the incipient faults which are caused by the short-circuit fault of a single phase PWM inverter. The single phase PWM inverter consists of four IGBTs and there is a total of six parameters that need to be observed for each IGBT. The parameter that could cause short-circuit fault to the IGBTs is identified by modifying the parameters of IGBT one at a time. The response at the inverter output is observed and recorded after each modification to the parameter value is done. From the results, it shows that parameter Threshold voltage (V ge(th) ) is identified to be able to generate the short-circuit incipient faults. For the application of detection the incipient faults using neural network, a total of 100 short-circuit incipient faults and one set of normal condition waveform are collected at the output of the single phase PWM inverter. These waveforms are then used to train the feedforward backpropagation neural network. One hidden layer feedforward backpropagation neural network of 7 neurons was trained and MSE of was obtained. It was shown that the trained feedforward backpropagation neural network was able to detect which IGBT component of the single phase PWM inverter produced the short-circuit incipient faults.

Importance of thermal radiation from heat sink in cooling of three phase PWM inverter kept inside an evacuated chamber

The paper describes a thermal analysis of a three-phase inverter operated under a Sinusoidal Pulse Width Modulation (SPWM) technique which used three sine waves displaced in 120° phase difference as reference signals. The IGBT unit is assumed to be placed with a heat sink inside an evacuated chamber and the entire heat has to be transferred by conduction and radiation. The main heat sources present here are the set of IGBTs and diodes which generates heat on a pulse basing on their switching frequencies. Melcosim (a well-known tool developed by Mitsubishi Electric Corporation) has been used to generate the power pulse from one set of IGBT and diode connected to a phase. A Scilab code is written to study the conduction and thermal radiation of heat sink and their combined effect on transient growth of the junction temperature of IGBT unit against complex switching pulses. The results mainly show that how thermal radiation from heat sink plays a crucial role in maintaining the junction temperature of IGBT within a threshold limit by adjusting various heat sink parameters. As the IGBT heat generation rate becomes higher, radiative heat transfer of the heat sink increases sharply which enhances overall cooling performance of the system.

Modeling and Simulation of Solar PV and DFIG Based Wind Hybrid System

Abstract The increasing energy demand and depletion of fossil fuels has risen in awareness of searching for alternative energy source thus the inexhaustible solar and wind energy is becoming an interesting topic which has grabbed the attention of researchers to make it sustainable power. The objective of this paper is to provide sustainable power for rural areas and remote places. This paper gives the architecture of hybrid system. The proposed system consists of solar PV and Doubly Fed Induction Generator (DFIG) based wind turbine. In Solar PV MPPT technique is used to maximize the power and boost converter is used to rise the DC voltage of solar PV and fed to the three phase PWM inverter. The DFIG has two controllers Rotor side control and Grid side control. Rotor side converter and Grid side Converter have the capability of generating or observing reactive power and to maintain constant rotor speed, and controls the DC-link voltage, controller for boost converter, inverter AC-DC-AC is implemented using vector control method. Simulation study of the proposed system is carried out with MATLAB Simulink and simulation results are provided.

Research of Off-Grid Household Photovoltaic Power System

The electricity shortage can be effectively alleviated by developing household photovoltaic power system in vast rural areas, it is necessary to establish simulation models. In this paper, the dynamic modeling of household photovoltaic power system including photovoltaic,Cuk-chopper circuit,battery and a single phase PWM inverter have been made in the ElectroMagnetic Transient Program /Alternative Transient Program(EMTP/ATP) software package.Control strategy based on MPPT for the power control of the inverter have been also developed. Operation characteristic of household photovoltaic power system was developed. Simulation results proved the validity of the model.

A ripple current minimisation based single phase PWM inverter

This paper is aimed at improving the output voltage waveform of a single phase PWM inverter. Two approaches is proposed, the first approach is based on selected harmonic elimination (SHE) of order up to 7th harmonic, for minimising harmonic distortion and modulating amplitude of the fundamental component of the output voltage waveform. For the first time, the Levenberg– Marquardt algorithm (LMA) is used for determining the switching angles of the inverter switches. The second approach is based on ripple current minimisation using LMA. A simulation model is developed using PSIM for the inverter to verify the proposed approaches. An experimental system was implemented to demonstrate the effectiveness of the proposed approaches by using PIC16F877 microcontroller. Analysis of the voltage THD as influenced by the amplitude modulation index is made using MATLAB based on the computed switching angles.

전류제어 루프를 갖는 선형 압축기 스트로크 제어기의 동적 성능 향상에 관한 연구

In this paper, a linear motor stroke controller using a phase lag filter and a single phase PWM inverter with a current controller has been implemented. In order to control the cooling capability of a refrigerator or an air conditioner in which linear compressors are applied, the piston speed should be controlled. The piston speed control can be obtained by adjusting the frequency or the stroke of linear motors. Generally, the frequency is fixed, for example, as 60Hz and the stroke is adjusted. The dynamic performance of linear compressors depends on how accurately the stroke or the piston position is controlled by the current applied. A linear motor piston position controller with a current control loop is proposed and verified via some simulation studies.

추가적인 센서가 필요 없는 3상 PWM 인버터의 LCL 필터 능동댐핑

In this paper, a new active damping method of LCL filter without capacitor voltage sensors is proposed for 3 phase PWM Inverter. Normally, L filter or LCL filter is used as an output filter of grid connected PWM inverter. An LCL filter has more excellent performance than L filter to reduce harmonic current, so the small inductance value can be used. However, the resonance problem in LCL filter is happen due to the zero impedance by the addition of LC branch. To solve the resonance problem, the various active damping method has been proposed so far. Generally, the virtual resistor active damping methods is required to additional hardware sensors for measurement of capacitor voltage and current. In this paper, the new active damping method is proposed without any capacitor voltage or current sensors. In the proposed method, the resonance component of the capacitor voltage of LCL filter can be observed by a simple MRAS(Model Reference Adaptive System) observer without additional hardware sensors, and this component is suppressed by feedforward compensation. The validity of the proposed method is proven by simulation and experiment on the 3-phase PWM inverter system.

Comparative Analysis of Voltage Control Signal Techniques for Single Phase Inverter

I n this paper, an experimental study is carried out to investigate the performance of various voltage control signal techniques for single phase PWM inverter. These techniques include single pulse width modulation, multiple pulse width modulation, sinusoidal pulse width modulation, modified sinusoidal pulse width modulation and phase displacement control. The performance of these carrier schemes are evaluated in terms of harmonic factor, total harmonic distortion and lowest order harmonic through simulation runs in MATALAB/Simulink. The technique with better harmonic spectrum is then implemented using an inexpensive and readily available AT89S52 microcontroller which generates the gating signals including dead time for switching devices comprising the inverter. The study can be employed for teaching the concepts of carrier schemes to undergraduate students taking the course of power electronics Index Terms—Contro l signal techniques, matlab/simulink, microcontroller at89s52, pulse width modulation, single phase inverter

ＥＤＬＣを用いた単相ＵＰＳの離散時間モデル追従制御

Electric Double Layer Capacitor (EDLC) has an environment-friendly impact and it has a lasting life than the conventional rechargeable battery. However, EDLC has the disadvantage of loss voltage by charge energy. In this paper, the single phase PWM inverter for UPS using buck-boost chopper with EDLC is applied in discrete-time model following control. It is established that this method compensates for output sine waveforms all regardless of rippling voltage in EDLC. The output voltage of the buck-boost chopper substantially covers charge energy in EDLC.