A photovoltaic-fed z-source inverter motor drive with fault-tolerant capability for rural irrigation

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). In recent years, photovoltaic (PV) systems have emerged as economical solutions for irrigation systems in rural areas. However, they are characterized by low voltage output and less reliable configurations. To address this issue in this paper, a promising inverter configuration called Impedance (Z)-source inverter (ZSI) is designed and implemented to obtain high voltage output with single-stage power conversion, particularly suitable for irrigation application. An improved and efficient modulation scheme and design specifications of the network parameters are derived. Additionally, a suitable fault-tolerant strategy is developed and implemented to improve reliability and efficiency. It incorporates an additional redundant leg with an improved control strategy to facilitate the fault-tolerant operation. The proposed fault-tolerant circuit is designed to handle switch failures of the inverter modules due to the open-circuit and short-circuit faults. The relevant simulation and experimental results under normal, faulty and post-fault operation are presented. The post-fault operation characteristics are identical to the normal operation. The motor performance characteristics such as load current, torque, harmonic spectrum, and efficiency are thoroughly analysed to prove the suitability of the proposed system for irrigation applications. This study provides an efficient and economical solution for rural irrigation utilized in developing countries, for example, India

Neutral-point Voltage Control of Three-level NPC Inverter for Three-phase APF based on Zero-sequence Voltage Injection

© 2019 IEEE. Active Power Filters (APF) have already adopted the three-level inverter topology in medium-voltage and high-power applications for solving power-quality problems. The Neutral-point voltage clamped (NPC) Inverter because of its robustness has become a matured and broadly used topology. It is necessary to maintain the neutral-point voltage at the DC-side as close to zero as possible. The focus of this paper is on the neutral-point voltage control of the three-level NPC inverter based on multicarrier PWM by manipulating the dwell time of small vectors by injecting a zero-sequence voltage into the modulating signal. The effectiveness of the presented method on a three-level NPC inverter is validated via simulation in MATLAB/Simulink. The results confirm the efficacy of the method in maintaining the neutral-point voltage at a minimum value with the desired overall good APF compensation characteristics

Tri-Objective LPV Controller Design for the Thermal Management of Motor Drive Parameters in an Electric Vehicle

The increase in consumption of fossil fuels in transportation sector causes global warming and greenhouse gas emissions. Electric vehicles (EVs) provide an alternate solution to this combustion of fossil fuels. They use traction motor drives (mostly induction type) instead of combustion engines, but these drives suffer from parameter (stator, rotor resistance and mutual inductance) variations that result in the deterioration of drive as well as vehicular performance. The increase in the ambient and operating temperatures experienced by EV in its desired driving cycle is the major cause of such parameter variations. This paper proposes a tri-objective linear parameter varying (LPV) controller and observer design that allows these variations without affecting the performance of motor drive and vehicle. The controller design incorporates the linear matrix inequalities (LMIs) to guarantee the inherent system stability and L2 gain bound. The performance of LPV controller is compared with that of proportional-integral-derivative (PID) controller in case of motor drive and vehicular dynamics. The MATLABbased nonlinear simulations are carried out and the results are presented in terms of driveś terminal characteristics and highway fuel economy test (HWFET) drive cycle. These results ensure the excellent robust performance of the proposed control technique

A-source Inverter-fed PMSM drive with fault-tolerant capability for Electric Vehicles

© 2020 IEEE. This paper demonstrates the fault tolerance performance of the A-source inverter fed PMSM drive system for electric vehicles. The proposed topology of the A-source impedance network is implemented to obtain high gain dc output for the inverter module. This high magnitude dc output is fed to the PMSM drive system for electric vehicle applications. In addition to the design strategies of the proposed system, this paper presents a fast fault identification and diagnosis strategy under switch faults occurring in the inverter module. The utilized method is robust to common converter issues such as load variations and input power fluctuations. The simulation results of the proposed fault-tolerant operation have been presented in this paper. This efficient fault-tolerant operation substantially improved the reliability of the overall system. The achieved results demonstrate the effectiveness of the proposed system with fault-tolerant capability for electric vehicle applications

Harmonic identification based on DSC and MAF for three-phase shunt active power filter

© 2019 IEEE. Harmonic current identification is very important in control of Active Power Filters. The dq Synchronous Reference Frame (SRF) based reference-current extraction technique has been widely utilized for this purpose. The dynamic performance of reference-current detection is dependent on numerical filters. In this paper, the two most popular filters, Delayed Signal Cancellation (DSC) and Moving Average Filter (MAF) are utilized in the rotating reference frame for both fundamental component identification and selective harmonic identification. A comprehensive comparison of the performance of these two filters is then carried out. Experimental results from digital implementation are provided to substantiate the theoretical analysis and simulation results