PWM inverter

PV inverters have been tested according the procedure defined in the EN 50530 standard-overall efficiency of grid connected photovoltaic inverters. Maximum power point tracking efficiency, static and dynamic, power electrical conversion and overall efficiencies are measured. Results for two models of microinverters and for one string inverter for comparison purposes are presented in this work.

Many advantages of a linear compressor over a reciprocating one have encouraged refrigerator manufacturers to develop linear compressors for various applications, including domestic refrigeration. In this paper, a micro control system for inverter based motor drives and a PWM inverter circuit for linear compressors are designed.  Also, a closed-loop stroke control system has been implemented. To demonstrate the practical significance of our results, we present some experimental results.
Keywords: linear compressor,  reciprocating compressor, PWM inverter, stroke control

In order to control the cooling capability of a refrigerator or an air conditioner in which linear compressors are applied, the piston stroke and current should be controlled instantaneously. Generally, the piston frequency is fixed as 60Hz and the piston stroke is adjusted. In this paper, performance analysis of instantaneous piston stroke in a single phase PWM inverter has been done for four different types of filters. These filters are used to calculate and control the maximum values of the estimated piston stroke and current instantaneously and to analyze the dynamic characteristics of the stroke control in a linear compressor system. Some simulation studies have been done to verify the feasibility of our control algorithms.

Keywords- linear compressor, piston stroke, PWM inverter, filter

This issue (DOI: 10.13140/RG.2.2.34778.75203) includes the following papers; P1181632510, AUTHOR="Fahim Salauddin", TITLE="DPCM Soft Modelling in Open-Loop Representations" P1111633511, AUTHOR="B. Dhouib and H. Hadj Abdallah", TITLE="Voltage Source Converter of Three Phase Photovoltaic Grid Connected System and Fault Analysis" P1111638520, AUTHOR="G.Swapna and N.KrishnaKumari and D.Ravi Kumar", TITLE="Sensor less Control of PMSM with FOC using MRAS", P1111634512, AUTHOR="Fethi Demim and Kahina Louadj and Aidene Mohamed and Abdelkrim Nemra", TITLE="Solution of an Optimal Control Problem with Vector Control using Relaxation Method", P1111636517, AUTHOR="Raheel Muzzammel and Umair Tahir", TITLE="Comprehensive Comparison of PWM and SVM based Three Phase AC to AC Matrix Converters", P1111641522, AUTHOR="Phi Hoang Nha and Dao Quang Thuy", TITLE="Improving the Characteristics of Switched Reluctance Motor"

This paper describes the effects of modulation techniques and the number of pulses on low power dissipation in a single-phase inverter and a multilevel inverter. Multilevel invert-ers and single-phase inverters given pulse input use PWM (Pulse Width Modulation), SPWM (Sinusoidal Pulse-Width Modulation) and PWL (Piecewise-Linear) modulation techniques, either in the form of square waves or multilevel pulses paired with the appropriate LCL filters. produce an inverter circuit that has a low THD (Total Harmonic Distortion) and high efficiency. The use of transformers is also mentioned in this paper to increase the source voltage at an output of 48 volts to around 220V-227Volt. Simulation results show that the effect of simple modulation switching techniques, such as PWM generated square waves, is simpler and more efficient if the right filter is used. The results of the simulation in PSpice show that of the switching techniques control in inverter system with fit filter can reduce the THD up to 1.81% and the efficiency is very high reaching of about 98%.

In this paper the Synchronous Reference frame PI-based control method for generating the reference signals for the Voltage Source Converter of Shunt Active Power Filter (SAPF) is presented. The method relies on the performance of the Proportional-Integral (PI) controller for achieving the best control performance of the SAPF. To improve the performance of the PI controller, the feedback path to the integral term is introduced to compensate the winding up phenomenon due to the integrator. Using Reference Frame Transformation, reference signals were transformed from c b a   stationery frame to q d   0 rotating frame. Using the PI controller, reference signals in q d   0 rotating frame were controlled to get the desired reference signals for the Pulse Width Modulation. Using MATLAB/SIMULINK, the 5 th , 7 th , and 11 th harmonics were used to test the proposed Active Power Filter with improved PI controller resulting in harmonic content down to 3.87%.

In a single-phase inverter switched using unipolar sine-triangle PWM, two sinusoidal modulating signals of equal amplitude and phase-shifted by 180 degrees are compared against a common triangular carrier to control the switching of the two inverter legs. This paper investigates the injection of a common-mode signal to the two sinusoids. It is shown that the common-mode signal added should comprise of even harmonics only in order to ensure waveform symmetry at the two inverter poles and that no low-frequency harmonic currents flow through the load. This paper identifies a common-mode signal, which results in clamping of each leg for 90 degrees in each half-cycle of the fundamental voltage. While even harmonic injection cannot increase the maximum line-line voltage for a given dc bus voltage, the proposed bus-clamping scheme reduces the inverter switching losses by half. Further, the proposed technique ensures that the losses in all the devices over a line cycle are equal.

In this paper the effects of a Static Synchronous Series Compensator, which is constructed with a 48-pulse inverter, on the power demand from the grid are studied. Extensive simulation studies were carried out in the MATLAB simulation environment to observe the compensation achieved by the SSSC and its effects on the line voltage, line current, phase angle and real/reactive power. The designed device is simulated in a power system which is comprised of a three phase power source, a transmission line, line inductance and load. The system parameters such as line voltage, line current, reactive power Q and real power P transmissions are observed both when the SSSC is connected to and disconnected from the power system. The motivation for modeling a SSSC from a multi-pulse inverter is to enhance the voltage waveform of the device and this is observed in the total harmonic distortion (THD) analysis performed at the end of the paper. According to the results, the power flow and phase angle can be controlled successfully by the new device through voltage injection. Finally a THD analysis is performed to see the harmonics content. The effect on the quality of the line voltage and current is acceptable according to international standards.

review.jpe.or.kr/On_line/admin/paper/files/13-JPE-0936.pdf

The paper involves the speed control of three phase induction motor by using the PWM fed VSI. Speed can
regulate by varying the external resistance in series with rotor circuit but this method is not so efficient.
Therefore this paper is focused on frequency control method for which a three phase induction motor drive
fed by Pulse width modulation Voltage source inverter. PWM is most reliable and efficient way to regulate
the output voltage of VSI. There are several ways to modulate the pulse width but this paper deals with
sinusoidal pulse width modulation technique. By varying the modulation index of SPWM then vary the
voltage of VSI. This technique minimizes the lower order harmonics and improves the response of VSI. The
transient rotor current, electromagnetic torque and rotor speed of the Induction Motor will improve.
Proposed model of open loop PWM Inverter fed induction motor drives in MATLAB/Simulink software.

In this paper, different sinusoidal pulse width modulation (SPWM) control strategies of multilevelflying capacitor inverter are presented. Three control strategies are studied; the triangular multicarrier SPWM, thesaw tooth multicarrier SPWM and the sinusoidal multicarrier SPWM. This work begins with a presentation of theflying capacitor inverter. Then a paragraph that gives a brief review of the triangular multicarrier SPWM, the sawtooth multicarrier SPWM and the sinusoidal multicarrier SPWM. A comparison between the three SPWM controlstrategies is established based on the simulation results. The comparison objects are the root mean square rms ofthe output voltage and the total harmonic distortion (THD). The results obtained demonstrate that the sinusoidalmulticarrier SPWM is better than the saw tooth multicarrier SPWM and the triangular multicarrier SPWM.Simulations are carried out by PSIM program.

This paper describes the effects of modulation techniques and the number of pulses on low power dissipation in a single-phase inverter and a multilevel inverter. Multilevel inverters and single-phase inverters given pulse input use PWM (Pulse Width Modulation), SPWM (Sinusoidal Pulse-Width Modulation) and PWL (Piecewise - Linear) modulation techniques, either in the form of square waves or multilevel pulses paired with the appropriate LCL filters. produce an inverter circuit that has a low THD (Total Harmonic Distortion) and high efficiency. The use of transformers is also mentioned in this paper to increase the source voltage at an output of 48 volts to around 220V-227Volt. Simulation results show that the effect of simple modulation switching techniques, such as PWM generated square waves, is simpler and more efficient if the right filter is used. The results of the simulation in PSpice show that of the switching techniques control in inverter system with fit filter can reduce the...

In an electric drive vehicle, the available voltage on
a DC-link is limited, and so the inverter output voltage and,
consequently, the line motor maximum speed are limited. The
fundamental voltage of the inverter output is increased
approximately 27% using a square wave switching pattern
instead of a sine wave switching pattern. However, this pattern
can only be used at high speeds, and at lower speeds a pulse width modulation pattern should be used. In order to achieve proper control, the switching pattern should be changed seamlessly. In the present paper, a new pulse width modulation (PWM) scheme for single-mode seamless control of Vernier motors is proposed.
In the proposed scheme, the reference voltage is modified to
change the switching pattern continuously so that the voltage
changes smoothly from a high-frequency pattern to a square
wave and voltage discontinuity does not occur. Experimental
results reveal that the inverter-switching pattern changes
smoothly from a sinusoidal pulse width modulation pattern to a
square wave pattern, and so seamless control from the constant torque region to the constant-power region, and vice versa, is achieved. Since the proposed scheme is a single-mode control, it is much simpler than current technologies, which are based on multi-mode controllers. Also the proposed method has a lower total harmonic disturbance (THD) as well as a lower harmonic distortion factor (HDF) compared to some existing methods.

A simple but powerful design method based on realcoded
Genetic algorithms (GAs) to solve the minimization of the
Total Harmonic Distortion (THD) criterion is obtained. GAs
provides a much simpler approach to off-line tuning of Pulse
width Modulation (PWM) switching angles than the rather
complicated non-genetic optimization algorithms. Genetic
algorithms are exploratory search and optimization procedures
that were devised on the principles of natural evolution and
population genetics.

This paper discusses a Static Synchronous Series Compensator which is constructed with a 48-pulse inverter. Extensive simulation studies are carried out to verify the proper operation of the mentioned Flexible AC Transmission Systems (FACTS) device. In MATLAB simulation environment the designed device is connected to a power system that is comprised of three phase power source, transmission line, line inductance and load. The system parameters such as line voltage, line current, reactive power Q and real power P transmissions are observed both when the Static Synchronous Series Compensator is connected to and disconnected from the power system. The compensation achieved by the SSSC and its effects on the line voltage, line current, phase angle and real/reactive power flow are examined in detail. The motivation of modeling a Static Synchronous Series Compensator from a multi-pulse inverter is to enhance the voltage waveform of the device and this is observed in total harmonic distortion (THD) analysis performed in the end. The results of the study shows that the voltage injection is successfully achieved by the new device and the power flow and phase angle can be controlled. Also the THD analysis assures that this is accomplished without comprising from the quality of the line voltage and current.

http://www.ajbasweb.com/ajbas/2009/1301-1314.pdf

Recent studies on optimal PWM switching strategies have shown great effort in developing techniques that fully utilizes the computational ability of the microprocessor rather than its memory space in generating the optimal PWM switching angles online in real time. However in suboptimal PWM strategy the modulating signal regarded as a non-sinusoidal waveform. It is assumed to be an arbitrary non-sinusoidal waveform, which is usually undefined. This arbitrary modulating wave is then sampled at twice the carrier frequency to produce the sampled amplitude modulated wave. However, the mathematical form of this function is determined by a special optimization process. Traditional optimization methods suffer from various drawbacks, such as estimation of initial parameters, prolonged and tedious computational steps and convergence to local optima. Thus in this paper genetic algorithm is used rather than traditional optimization methods to find the optimal switching angles in suboptimal PWM strategy by minimizing the distortion factor. These optimal switching angles are used to calculate the sampled points which are used to determine the optimal non-sinusoidal modulating signal. A curve fitting technique is used to determine the optimal non-sinusoidal modulating signal using MATLAB program. A simulation result shows different cases with different modulation depth to minimize the output distortion factor and to improve the three-phase inverter performance.

This paper gives a detail modelling of six phase Permanent magnet synchronous machine (PMSM) and complete simulation of it’s drive system and performance analysis in different speed with PI controller. proposed method can be used easily in many applications like ship propulsion, Hybrid electric vehicle, Washing machine, Ship propulsion, Traction, Spinning mills, Aerospace etc. Proportional-Integral controller is mostly used in drives system. The combination of proportional and integral is important to increase the speed of response and also to eliminate the steady state error. Performance analysis with proportional (Kp) and integral (Ki) constant with different speeds and constant torque is studied in the drive system.

A new voltage control method for single-phase full-bridge PWM inverters that having an output LC filter is proposed in this paper. The proposed voltage controller has a capability to realize a zero steady- state output voltage error with fast response. The zero steady-state output voltage error is achieved by using a controller that is derived by using the virtual LC resonant circuit. Fast response is obtained by using a virtual resistance that is connected in parallel with the filter capacitor. The validity of the proposed method is verified by experimental results. A new voltage control method for single-phase full-bridge PWM inverters is proposed in this paper. The proposed voltage controller has capability to realize a zero steady-state output voltage error with fast response without complicated transformation. To control the output voltage, a voltage control based on new virtual LC resonant circuit is proposed. By using the proposed control technique, a zero steady-state error ...

Graphical User Interface (GUI) based systems are flourishing their popularity in the industrial area in
present days. If it is possible to integrate the GUI based systems with a Global System for Mobile (GSM)
modem for controlling and monitoring, it will be magnificently acceptable communication system. In this
paper a method is presented on a distant machine and motor control system monitoring and controlling,
using a GSM modem and GUI. PIC microcontroller is used to bridge and synchronize the operation of GUI
and GSM systems.

The purpose of this paper is to improve the output quality of three-phase PWM DC-AC inverter. The improvement in output quality is required to reduce the harmonic components. The PWM control can reduce harmonic components by adjusting the width of each pulse. We design the switching phase to improve output quality, also propose an evaluation function for evaluating the frequency components. In order to optimize the switching phase, particle swarm optimization is applied.
We confirm the effectiveness of the proposed method comparing with other methods. Moreover, we confirm the effectiveness by using the implementation circuit of the three-phase inverter.

This paper discusses a 48-pulse H-bridge PWM inverter which utilizes a quasi-resonant topology that is comprised of a clamping circuit and a resonant circuit, in order to achieve soft switching. The use of a multi-pulse inverter increases the quality of the output whereas the implementation of soft switching technique increases the overall efficiency of the inverter by decreasing switching losses that reach considerable values with the abundant number of switches and a switching frequency of the order of KHz. Furthermore, in order to be able to respond load variations a feedback loop is constructed with a PI controller to realize closed loop current control. This system is aimed to be a building block for FACTS devices such as Static Synchronous Series Compensator (SSSC). The motivation of designing a more efficient and dynamic inverter with high power quality is to construct more efficient and effective FACTS devices.

http://insipub.com/ajbas/2009/1814-1826.pdf

Corresponding Author: Taha Selim Ustun, Department of Electrical Engineering University Malaya Kuala Lumpur, Malaysia E-mail: tahaselim@yahoo.com Phone: +6014-320-2881 Fax: +603-7957-5316 1301 ... Power Line Compensation Study of a Static Synchronous ...

This paper presents a single-phase five-level inverter topology for grid-connected PV systems with a novel Pulse Width-Modulated (PWM) control scheme. Two reference signals identical to each other with an offset equivalent to the amplitude of the triangular carrier signal were used to generate PWM signals for the switches. A proportional-integral current control algorithm is implemented in MATLAB/SIMULINK to keep the current injected into the grid sinusoidal and to have high dynamic performance with rapidly changing atmospheric conditions. The inverter offers much less total harmonic distortion and can operate at near-unity power factor. A Proportional Integral (PI) current control algorithm is implemented to optimize the performance of the inverter. Simulation results indicate that the Total Harmonic Distortion (THD) of the five level inverter is much lesser than that of the conventional three-level inverter. Further, both the grid voltages and grid current are in phase at near-uni...

Properties of powder core based inductors when utilised in a passive filter of the voltage source inverter are investigated to highlight the importance of considering the soft-saturation nature of powder materials in determining the inductance when subjected to varying load current. Simulations were carried out in ANSYS Maxwell and Simplorer to understand the magnetic behaviour of inductors under pulse width modulation in a three-phase inverter. Variation of the effective inductance due to soft saturation nature of the powder cores is utilised to achieve the inductance demanded by the passive filter at the design stage.

In this study, a novel sinusoidal PWM switched AC/DC/AC converter interface scheme using real novel triloop voltage error tracking fuzzy logic controller (FLC), to stabilize the stand alone Wind Energy Conversion Scheme (WECS) using an induction generator. The proposed novel sinusoidal Pulse Width Modulator (SPWM) switched (AC/DC/AC) converter (diode rectifier and 6-pulse IGBT inverter) interface scheme serves as a combined voltage stabilization regulator and maximum wind energy utilization and enhancement compensator.