Efficient fault-tolerant systems with high reliability and enhanced power quality for green energy applications
In the modern era of development, green energy resources are being advocated by many countries to meet increasing demands for electrical energy due to the rapid depletion of non-renewable resources. For instance, the implementation of electric vehicles has gained popularity as an effective measure for dealing with the energy crisis and environmental pollution. Similarly, solar Photovoltaic (PV)-based and wind energy generation has emerged as an important alternative to water pumping in the irrigation sector. These systems are driven by conventional modules of dc-ac power conversion and this single-stage power conversion has the disadvantages of complex modulation control, limited ac output, and low power quality. Besides, such arrangements of inverter modules are susceptible to switch or sensor failures and the control strategy can become more complex with high-voltage operations. With rising concerns over safety, the question of reliability has gained attention in critical applications namely, electric vehicles, PV-fed irrigation systems, and wind energy conversion systems. It has been observed that conventional converter topologies cannot suffice for the high-voltage magnitude required for the operation of motor drives. They also lack the integration of fast and cost-effective methods for the identification, isolation, and reconfiguration of faults. Hence, the need for a high-gain power converter with efficient fault-tolerant capabilities is a demanding challenge to cater to the needs of industries. To address the above-mentioned issues, this research work presents a design and thorough analysis of new topologies of impedance-source converters with higher boost capabilities. Additionally, the fault-tolerant capability of the proposed topologies of power converters is investigated for switch failures of the inverter module, sensor, and actuator failures. Regarding electric vehicle applications, a Bidirectional-Z-source inverter (Bi-ZSI)-fed induction motor drive is proposed with fault-tolerant capabilities. A suitably fast detection and diagnosis scheme to isolate the faulty leg and resume the normal operation is experimentally validated in this work. Secondly, an online estimation method based on the Kalman filter approach is designed and implemented for an induction motor drive system to provide fault-ride through capabilities during sensor outages in Electric Vehicles. Thirdly, a promising inverter configuration is designed and implemented to obtain a high voltage output with single-stage power conversion, that is particularly suitable for a PV-fed irrigation system. Besides, the proposed fault-tolerant circuit is designed to handle switch failures of inverter modules due to open-circuit and short-circuit faults. Last, a new topology of impedance source network, called a Sigma-Z-source network, is proposed for a wind energy system. Also, a suitable data-driven Reinforcement learning-based Algorithm is proposed to facilitate the fault remedial strategy during actuator faults in Permanent Magnet Synchronous Generator (PMSG)-fed wind energy conversion system (WECS). This research is especially of great interest in crucial applications involving automotive and green energy resources, as these applications require strict protocols for ensuring safety. The proposed strategies are characterized by low-cost prototypes, fast responses, and better efficiency compared to current techniques. These strategies will minimize irregular maintenance schedules (a problem with current strategies), which will increase output without having to compromise on industry safety requirements.