Phase Inverter System Research Articles

Voltage Sag Mitigation in PV Boot-Strap Converter Inverter System

This-effort displays an idea to straightforwardly mitigate sag in PV-Inverter system. ‘This effort deals with designing, modeling &comparison of PV fed Bootstrap converter and three phase inverter (PVBSCTPI) system with and without LVRT (Low voltage ride through). Here, PV is utilized as a source.„_The-Simulink-models for-PVBSCTPI with and without LVRT have been-developed using the-elements of Simulink&-investigations are executed. The outcomes are compared-in terms-of output voltage, Real & Reactive power. The outcomes represent that voltage sag of PVBSCTPI system is mitigated using a DVR. The improved performance-in terms-of voltage has been obtained with LVRT based - PVBSCTPI system. The output voltage and power are found to be higher with LVRT.

English

English

저압배전선로 전압안정화를 위한 상태관측과 반복제어를 적용한 무효전력 보상기

In this paper, a new reactive power control algorithm using a stat observer and repetitive control for voltage adjustment to the low-voltage distribution line is proposed and verified by simulation and experiment. A reactive power compensator has a single -phase full bridge inverter structure and consists of DC voltage controller to maintain a constant DC voltage, and current controller for reactive power generation. A DC ripple compensation method use an output from the state observer and the output is used as the DC voltage controller feedback to regulate the DC voltage constant. In order to inject a stable reactive power, the fundamental component of current is controlled by a PI controller, and a repetitive controller is connected in parallel with the PI controller to compensate for lower-order harmonics. The repetitive controller, as implemented in the synchronous coordinate system, serves to eliminate low-order odd harmonic components. The proposed control technique is experimented with a ±5kVar single phase inverter system and verified the performance of the proposed algorithm by confirming that THD is reduced to 2% from 9%.

분산 제어 기법을 사용한 삼상 인버터 제어기 개발

Electric power conversion system market is expanding as renewable energy industry rapidly grows. Most of these electric power conversion systems typically ranging from 10kW to 250kW, are controlled by high speed digital signal processor. This paper proposes a three phase inverter system each arm of which is equipped with DSP together with gate driver. In existing inverters, main DSP generates PWM signals and controls all three arms. In the proposed inverter, each arm is independently self-controlled by dedicated DSP that measures phase voltage/current and generates PWM signals, according to synchronization and control reference data sent by main DSP via serial communication ie. CAN communication. The proposed controller can be used for unballenced 3phase load. The experimental results are proposed for proving the control methode.

PID Control of a Three Phase Photovoltaic Inverter Tied to a Grid Based on a 120-Degree Bus Clamp PWM

This paper presents a new operating type of a three phase photovoltaic PID current control system connected to the low voltage distribution grid. This operating type introduces a 120-degree bus clamp PWM control method (120° BC-PWM). A 120° BC-PWM is a special switching sequences technique employing bus clamp sequences that use only one phase under a PWM and PID control state every 60° while the other phases are being clamped. The BC-PWM method was used to generate six PWM signals to control a three phase inverter system every 60° with constant power input and a small dc link film capacitor. The main objective of this paper is to use new PWM techniques with a PID current control method to reduce the switching losses of three phase inverters. The losses were reduced to 1/3th for each transistor by reducing the time operation for each transistor. The simulation results of the BC-PWM method show an improvement in the performance of the three phase inverter system connected to the grid. Simulation setup of the system obtained is built by using a SiC MOSFET, 5 kVA, 400 V line-line and 25 kHz switching frequency. The PID control is not continuously active for each phase but is operational in 60° and saturated at 120° in a half period. Following a proper tuning of the windup, it recovers very easily.

The study on DC-link Film Capacitor in 3 Phase Inverter System for the Consideration of Frequency Response

The study on DC-link Film Capacitor in 3 Phase Inverter System for the Consideration of Frequency Response

Single Phase Inverter System using Proportional Resonant Current Control

<span>This paper presents the harmonic reduction performance of proportional resonant (PR) current controller in single phase inverter system connected to nonlinear load. In the study, proportional resonant current controller and low pass filter is discussed to eliminate low order harmonics injection in single phase inverter system. The potential of nonlinear load in producing harmonics is showed and identified by developing a nonlinear load model using a full bridge rectifier circuit. The modelling and simulation is done in MATLAB Simulink while harmonic spectrum results are obtained using Fast Fourier Transfor. End result show PR current controller capability to overcome the injection of current harmonic problems thus improved the overall total harmonic distortion (THD).</span>

Modeling and Fuzzy Logic Control of PV Based Cascaded Boost Converter Three Phase Five-level Inverter System

Power Quality development using PV based boost cascaded inverter system is one of the reliable methods. This paper handle with modeling and fuzzy logic control of boost to boost cascaded three phase inverter system with PV as source. MATLAB simulink model for BBCIS has been developed using the elements of simulink and cascaded loop investigations are performed with PI and Fuzzy Logic Controllers. The dynamic responses of the above systems are compared in terms of time domain parameters. The consequences point to that maximum power is obtained with minimum THD using FLC.

Application of PI Current Controller in Single Phase Inverter System Connected to Non Linear Load

This study is concerned with the problem of network power quality when inverter systems are connected to a nonlinear load. Nonlinear loads are well known as one of the biggest source of harmonics in the power system. Besides that, inverter systems also have their nonlinearity characteristic because of the electronic components. As the inverter system is connected to nonlinear load, it resulting in harmonic distortion-related problem and draw non-sinusoidal currents in the system, thus reducing the power quality in the system. The application of Proportional Integral controller in this system is the main interest of this study. This current controller capable of reducing total harmonic distortion and improve the state of current waveform. This paper focuses on application of simple manual trial and error tuning technique to produce the optimum value for the gains. The result of study verifies the trial and error manual tuning of PI current controller in compensating harmonic distortions. Simulation and modelling of the system are successfully developed using Matlab/Simulink.

New Gen Algorithm for Detecting Sag and Swell Voltages in Single Phase Inverter System

In this manuscript, a novel sag and peak detector by means of a delta square operation for a single-phase is suggested. The established sag detector is from a single phase digital phase-locked loop (DPLL) that is founded on a d-q transformation employing an all-pass filter (APF). The d-q transformation is typically employed in the three-phase coordinate system. The APF produces a virtual phase with a 90 deg phase delay, but the virtual phase can not reproduce an abrupt variation of the grid voltage, at the moment in which the voltage sag transpires. As a consequence, the peak value is severely garbled, and settles down gradually. A modified APF produces the virtual q-axis voltage factor from the difference between the current and the former value of the d-axis voltage component in the stationary reference frame. Nevertheless, the amended APF cannot sense the voltage sag and peak value when the sag transpires around the zero crossing points such as 0 deg and 180 deg since the difference voltage is not adequate to sense the voltage sag. The suggested algorithm is proficient to sense the sag voltage through all regions as well as the zero crossing voltage. Furthermore, the precise voltage drop can be obtained by computing the q-axis component, which is relational to the d-axis component. To authenticate the legitimacy of the suggested scheme, the orthodox and suggested approaches are contrasted by means of the simulations and investigational results.

New Gen Algorithm for Detecting Sag and Swell Voltages in Single Phase Inverter System for Micro grid

In this manuscript, a novel sag and peak detector by means of a delta square operation for a single-phase is suggested. The established sag detector is from a single phase digital phase-locked loop (DPLL) that is founded on a d-q transformation employing an all-pass filter (APF). The d-q transformation is typically employed in the three-phase coordinate system. The APF produces a virtual phase with a 90° phase delay, but the virtual phase can not reproduce an abrupt variation of the grid voltage, at the moment in which the voltage sag transpires. As a consequence, the peak value is severely garbled, and settles down gradually. A modified APF produces the virtual q-axis voltage factor from the difference between the current and the former value of the d-axis voltage component in the stationary reference frame. Nevertheless, the amended APF cannot sense the voltage sag and peak value when the sag transpires around the zero crossing points such as 0° and 180° since the difference voltage is not adequate to sense the voltage sag. The suggested algorithm is proficient to sense the sag voltage through all regions as well as the zero crossing voltage. Furthermore, the precise voltage drop can be obtained by computing the q-axis component, which is relational to the d-axis component. To authenticate the legitimacy of the suggested scheme, the orthodox and suggested approaches are contrasted by means of the simulations and investigational results.

DSPIC BASED POWER ASSISTED STEERING USING BRUSHLESS DIRECT CURRENT MOTOR

This study illustrates the Electrically Assisted power Steering (EAS) using BLDC motor for a vehicle. Earlier the Electrically Assisted power Steering (EAS) was implemented with DSP. This study shows the usage of a dsPIC to control the BLDC motor with an encoder. The BLDC motor here is driven by dsPIC through a three phase inverter system. IRAMS type of inverter is used which is cost efficient and space efficient. The dsPIC supplied with the input of the steering. In its higher capacity the vehicles speed controller acts as the assistance level controller for steering effort. At the lower capacity, the torque controller gives the effort level control. In reality this can be realized as torque sensor and vehicle sensor interfaced in the dsPIC. For actual implementation in the system, a dsPIC-based BLDC motor controller with three-phase inverter module is used with Hall-effect sensor feedback. It is designed in such a way that the driver assistance can be varied at any time without any difficulty.

삼상 인버터의 한상 개방 고장 시 PMSM 토크제어 알고리즘

A torque control algorithm suitable for detecting an open circuit failure in which one of the three phases is unable to supply power to a motor in the permanent magnet synchronous motor is presented in this paper. When the failure occurs in the inverter, the output torque of motor is restricted. A new method which is implemented by using only a processor algorithm internally without any hardware redundancy circuit is proposed. A simulation and experimental study is carried out with a three phase inverter system to show the validity of the proposed method.

FPGA Based Optimized Discontinuous SVPWM Algorithm for Three Phase VSI in AC Drives

The discontinuous space vector pulse width modulation (SVPWM) has well-known that can reduce switching losses. By simplifying the thermal management issues, the discontinuous SVPWM can potentially reduce the inverter size and cost. However, using the modulation due to different time interval equations for each sector can introduce glitches at the points when the sector is changed. The more main problem, it can increase unwanted harmonic content and current ripple. Consider the decrease in switching losses associated with discontinuous modulation allows the system to utilize a higher switching frequency, this paper present high frequency switching of optimized discontinuous SVPWM based on FPGA to overcome the problems above. The proposed SVPWM has been successfully implemented by using APEX20KE Altera FPGA to drive on a three phase inverter system with 1.5 kW induction machine as load. The results have proved that the method can reduce harmonic content and current ripple without glitches. DOI : http://dx.doi.org/10.11591/ijpeds.v3i1.735

Simple Realization of 5-Segment Discontinuous SVPWM Based on FPGA

The Space Vector Pulse Width Modulation (SVPWM) is possibly the best among all the PWM techniques for variable frequency drive applications. Unfortunately, the modulation algorithm is mainly implemented with software based on microcontroller or digital signal processors (DSP). These are software-based technique purely and obviously not an ideal solution. Employing Field Programmable Gate Array (FPGA) to realize SVPWM strategies provides advantages that it is considered as an appropriate solution to boost system performance of an SVPWM algorithm. Moreover, although in the literatures the implementation for three-phase SVPWM based on FPGA is not lacking, however all these designs are based on the conventional SVPWM without considering hardware-resource saving and not simple. This paper present a simple realization of 5-segment discontinuous SVPWM with a difference approach based on FPGA, in which the judging of sectors and the calculation of the firing time to generate the SVPWM waveform is simple, and also the switching losses is low. The proposed discontinuous SVPWM has been designed and successfully implemented by using APEX20KE Altera FPGA considering hardware-resource saving and has successfully driven a three phase inverter system with induction machine 1.5 kW as load.

An analysis of design conditions for a phase-inverter speaker system with a drone cone

In this paper useful design conditions for a phase-inverter speaker system with a drone cone, which realize a flat response, are given for the first time by applying the network synthesis theory to the sound-pressure transfer function of this speaker system. The design conditions are obtained in relation to the sound-pressure zero below the reproducing region for the cases of the general Butterworth and the general Chebyshev rational function characteristics, and also obtained in relation to the amount of ripple of the sound-pressure frequency response in the reproducing frequency region for the case of the general Chebyshev rational function characteristic. The effects of equivalent resistance of the box due to the absorbing material on the design conditions are also considered. The calculated sound-pressure frequency response based on the design conditions obtained agrees fairly well with the measured response. Comparison of the sound-pressure frequency response of this speaker system with those of the closed box and the bass-reflex system is also given.