In this paper, a three-phase multilevel cascaded H-bridge inverter is developed for injecting renewable power energy into the grid through a filter. The main contribution of this work is to reduce the total harmonic distortion (THD) by using a passive filter and to enhance the output voltages by adopting a multicarrier pulse width modulation (MCPWM). The simulation results affirm a good performance of the proposed multicarrier PWM control using a three-phase five-level inverter. The proposed inverter is tested as well as the THD and the spectral analysis of the output voltage are calculated using Simulink/Matlab software.

https://ijpeds.iaescore.com/index.php/IJPEDS/article/download/13280/11483

A Multicarrier PWM Technique for Five Level Inverter Connected to the Grid

Performance analysis of multiple gain boost converter with hybrid maximum power point tracker for solar PV connected to grid

Induction Motors (IM) are work horse of power industries. Controlling of IM is crucial task in most of the applications. This paper presents implementation of a Variable Frequency Drive (VFD) controller for a three phase induction motor driven by single phase supply on an Arduino platform. The hardware setup involves a rectifier-inverter combination along with a DC link. The present work concentrates on programming the timers of ATMEGA 2560 microcontroller to obtain the required switching pulses. The simulation results of the developed switching control technique with due validation from a hardware setup are presented.

Arduino based V/f Drive for a Three Phase Induction Motor using Single Phase Supply


 In this paper, a multistring-multilevel inverter (M-MLI) for renewable-energy-source applications has been proposed with reduced switch count and harmonics along with single-switch fault analysis for various levels. It requires only ‘m+1’ power switches for ‘m’ voltage levels. The proposed work achieves the fine-tuning of switching angles using a metaheuristic technique, i.e. the teaching–learning-based optimization algorithm (TLBOA), to mitigate the total harmonic distortion (THD) of the M-MLI. Furthermore, the proposed TLBOA has been compared with conventional modulation techniques such as equal phase (EP), half-equal phase (HEP), near-level control (NLC) and Newton–Raphson (NR) to verify the effectiveness of TLBOA for various voltage levels in terms of % voltage-THD (%V-THD), computational time and methodology. By fine-tuning the switching angles, the %V-THD is improved significantly when compared with EP, HEP, NLC and NR modulation techniques. For an 11-level single-phase M-MLI, the %V-THD using TLBOA at 0.91 modulation index (MI) is 5.051%. The lower-order harmonics, i.e. 5, 7, 11 and 13, are eliminated to improve the power quality. Furthermore, MLIs are often prone to failure, resulting in waveform distortion. The extreme reduction in power quality impacts the load and significant damage is likely. The location of the open-circuit fault to be identified becomes more tedious under the faulty conditions with increased switch counts and voltage levels since the mathematical modelling fails to address the scenario in less computational time. Hence, the machine-learning approach, i.e. support vector machine (SVM) with Bayesian optimization, has been discussed to locate the faulty switch. Finally, the proposed M-MLI configuration has been modelled, simulated and validated using MATLAB® and Simulink®. The results of the M-MLI configuration have been verified for 7, 9 and 11 levels using TLBOA along with fault analysis using the SVM approach.

/pdf/switching-angle-optimization-and-fault-analysis-of-a-1n3fc8z3.pdf

Switching angle optimization and fault analysis of a multistring-multilevel inverter for renewable-energy-source applications

Modelling and control of wind energy conversion system: performance enhancement


 In this paper, the performance of a permanent magnet synchronous generator (PMSG)-based wind energy conversion system (WECS) supplied to an uncontrolled rectifier-fed boost converter (BC) interfaced with a three-phase T-type three-level inverter (TLI) has been analysed. The proposed WECS involves three converters, namely an uncontrolled rectifier that is used for conversion from AC to DC; a BC supplied by a PMSG-fed rectifier used to enhance the voltage gain; and a grid-connected three-phase T-type TLI is proposed to eliminate power-quality issues with synchronization of grid voltage and current. The main goal of this research is to model and control the grid-connected T-type TLI using a d–q synchronous frame for wind energy for regulating the DC-link voltage and transferring the generated wind power from the BC to the grid. Furthermore, the perturb & observe (P&O)-based maximum power point (MPP) approach is recommended to keep track of the MPP for a BC that is supplied from a PMSG-based WECS under constant and variable wind speeds. The proposed PMSG-based WECS interfaced with grid-connected T-type TLI using d–q control has been computationally modelled, simulated and validated with constant and variable speeds using MATLAB® and Simulink®. It is confirmed that the P&O-based MPP approach ensures maximum power for varying wind speeds, and the total harmonic distortion of the T-type TLI grid current value is 3.18%, which is within IEEE-519 limits. Furthermore, with grid synchronization, the power factor of the T-type TLI is maintained at unity to avoid power-quality issues.

https://academic.oup.com/ce/article-pdf/6/4/534/44548095/zkac034.pdf

Wind energy conversion system using perturb & observe-based maximum power point approach interfaced with T-type three-level inverter connected to grid

Brushless excitation system is widely used in large capacity synchronous generators since it removes the usage of commutator, brushes and slip rings, hence reduces the losses, maintenance and increases reliability. Rotating Rectifier Assembly (RRA) is the main part of brushless alternator. Due to ageing phenomenon and continuous process regime, diodes in rotating rectifier can fail either due to Open Circuit (OC) or Short Circuit (SC), which overloads the exciter and hence the alternator can no longer run securely. If such condition is prolonged, the Automatic Voltage Regulator (AVR) as well as the exciter windings can be damaged.This paper presents two different methods of diode failure detection in brushless alternators. First method uses an algorithm based on output voltage and the second uses the ripple factor of the exciter field current. Diode failure condition is detected for different type of loads connected to 4 kVA, 380 V, 50 Hz, 4 poles generator with 14 pole exciter (brushless alternator) and the results are verified using MATLAB/Simulink. Also, the protection schemes for rotating diode assembly as well as exciter field windings are presented using Metal Oxide Varistor (MOV) and Discharge Resistor.

Detection of Rotating Diode Failure Condition & its Protection in Brushless Alternator

The aim of this paper is to explore the use of various current mode control (CMC) techniques to design a single phase grid tie inverter integrated with anti-islanding protection. Three types of CMC techniques have been discussed, namely current hysteresis control (CHC), constant frequency control (CFC) and average current mode control (ACMC). The performance of the grid tie inverter in the event of grid voltage failure is also studied to help install an anti-islanding mechanism. The proposed control techniques shall eliminate the use of Phase locked loop (PLL) control as the current reference is generated from the grid voltage itself. All three current mode control techniques of an inverter have been simulated in MATLAB/Simulink to evaluate the performance of the designed inverter. The simulated results show a current THD of less than 5% in all three methods and a good anti-islanding response.

https://ijpeds.iaescore.com/index.php/IJPEDS/article/download/20868/13343

Pranupa S

Papers

Wind energy conversion system using perturb & observe-based maximum power point approach interfaced with T-type three-level inverter connected to grid

Arduino based V/f Drive for a Three Phase Induction Motor using Single Phase Supply

Detection of Rotating Diode Failure Condition & its Protection in Brushless Alternator

Current mode control of single phase grid tie inverter with anti-islanding