Artificial intelligence for photovoltaic systems

Photovoltaic systems have gained an extraordinary popularity in the energy generation industry. Despite the benefits, photovoltaic systems still suffer from four main drawbacks, which include low conversion efficiency, intermittent power supply, high fabrication costs and the nonlinearity of the PV system output power. To overcome these issues, various optimization and control techniques have been proposed. However, many authors relied on classical techniques, which were based on intuitive, numerical or analytical methods. More efficient optimization strategies would enhance the performance of the PV systems and decrease the cost of the energy generated. In this chapter, we provide an overview of how Artificial Intelligence (AI) techniques can provide value to photovoltaic systems. Particular attention is devoted to three main areas: (1) Forecasting and modelling of meteorological data, (2) Basic modelling of solar cells and (3) Sizing of photovoltaic systems. This chapter will aim to provide a comparison between conventional techniques and the added benefits of using machine learning methods

Analysis of power losses and Lifetime for the inverter in electric Vehicles using variable voltage Control and variable switching Frequency modified pwm

With the increasing demand for reduced emissions and improved fuel economy, the automakers are focusing on the development of electric vehicles (EVs). The performance requirements for EVs includes high driving range and long life of its components. The power converters are among the most stressed and less reliable EV drivetrain components. Hence, improving the lifetime of the power converters is essential for the success of EV adoption. The lifetime of the power converters can be improved by reducing thermal stress of the power devices, which represents the main cause of failure. Since the temperature and power losses of the power device are proportional, thermal stress can be reduced by minimizing the power losses. In addition to the lifetime improvement, minimizing the power losses of the power converters can extend the EV range since the power demand under a given loading conditions is reduced. In this regard, this thesis aims to study the impact of an existing power loss reduction technique known as variable dc-bus voltage control (VVC) on the inverter lifetime. In addition, it proposes a new pulse width modulation (PWM) strategy called variable switching frequency modified PWM (VSF-MPWM) for three-phase two level voltage source inverter. The VSF-MPWM aims to minimize the inverter power losses, but without sacrificing the output current quality. In order to study the impact of the VVC on the inverter lifetime, a lifetime estimation method is first presented. This method uses the Artemis urban and US06 driving cycles in order to obtain the thermal loading, and consequently the lifetime consumption of the inverter power devices. Then, the VSF-MPWM is proposed, which minimizes the switching loss by clamping any of the three-phase legs at the phase current peak and by reducing the number of commutations through variable switching frequency. However, in order to achieve an acceptable current quality, the proposed VSF-MPWM controls both the clamping period and the switching frequency according to the current quality constraints of the conventional PWM strategy. The impact of the VVC on the inverter lifetime and the performance of the proposed VSF-MPWM on the inverter power losses and current quality are investigated through MATLAB Simulink. The lifetime analysis reveals that the VVC has the ability to improve the lifetime of the inverter by a factor of 5.06 and 3.43 under Artemis urban and US06 driving cycles, respectively, compared to the conventional constant dc-bus voltage control (CVC). On the other hand, the simulation result shows that the proposed VSF-MPWM can save up to 35.4 % and 23.8 % of switching and power losses, respectively, compared to the conventional PWM. Meanwhile, the VSF-MPWM can obtain the same output current quality as that of the conventional PWM

A comparative review of three different power inverters for DC–AC applications

This paper presents a comparative review of three different widely used power inverters, namely the conventional six-switch inverter; the reduced switch count four-switch inverter; and the eight-switch inverter. The later inverter can be reconfigured as a neutral-point diode-clamped inverter at the failure of one inverter leg. The three power inverters are compared and discussed with respect to cost, complexity, losses, common mode voltage, and control techniques. The paper is intended to serve as a guide regarding selecting the appropriate inverter for each specific application. Simulation results are presented to demonstrate the performance of the three power inverters, followed by a comprehensive comparison between the three power inverters

Recent Advances of Wind-Solar Hybrid Renewable Energy Systems for Power Generation: A Review

A hybrid renewable energy source (HRES) consists of two or more renewable energy sources, such as wind turbines and photovoltaic systems, utilized together to provide increased system efficiency and improved stability in energy supply to a certain degree. The objective of this study is to present a comprehensive review of wind-solar HRES from the perspectives of power architectures, mathematical modeling, power electronic converter topologies, and design optimization algorithms. Since the uncertainty of HRES can be reduced further by including an energy storage system, this paper presents several hybrid energy storage system coupling technologies, highlighting their major advantages and disadvantages. Various HRES power converters and control strategies from the state-of-the-art have been discussed. Different types of energy source combinations, modeling, power converter architectures, sizing, and optimization techniques used in the existing HRES are reviewed in this work, which intends to serve as a comprehensive reference for researchers, engineers, and policymakers in this field. This article also discusses the technical challenges associated with HRES as well as the scope of future advances and research on HRES