Optimal Operation of Automotive Electrical System with Photovoltaic Generation and Three-level Battery Management Scheme

For many years, the electrical power requirements in Automotive Electrical System (AES) have been quickly increasing and are predicted to continue to climb. This trend is being pushed by the introduction of a slew of new vehicle features. The constant growth in power needs is stretching the limitations of current automotive power generation and control technologies, stimulating the development of higher-power and higher-voltage electrical systems and components. Electrical power on a vehicle is not free. It comes as a direct result of consuming fuel within the engine to drive the alternator. With a typical engine efficiency of 44% and with present fuel costs this leads to onboard electrical power costs 4 times more than a typical household utility rate. Global oil and gas resource depletion, as well as environmental concerns, have prompted the automobile industry to build more efficient and eco-friendly cars in order to minimize fuel use and safeguard the environment. In our proposed Automotive Electrical system configuration, we have an AES system which is powered by an automotive alternator and battery combination where the alternator is driven by an IC engine and we have a hybrid energy system using a Rooftop PV array with a battery management system (BMS). We discovered that during the off state, the whole load of the automobile is dependent on the 12Vlead acid battery for power, which causes the SOC to drop dramatically. As a result, the suggested model will include a flexible thin-film solar PV module positioned on the rooftop, which will be supported by a Maximum Power Point (MPPT) Tracking charge controller and will deliver energy to recharge the extra battery and meet the electrical requirements when the vehicle is stationary. When the vehicle is in motion, the existing alternator in the car's electrical system takes over the battery charging requirements, by this way, we can meet the electrical requirements of AES without running the engine for a long time by consuming fuel. The proposed model specialty is investigated using MATLAB/Simulink and compared with existing methods. Keywords: Automotive Electrical System (AES), Internal Combustion Engine (ICE), Hybrid Energy System, Rooftop PV array, Maximum Power Point Tracking (MPPT).

Improved Invasive Weed Optimization Algorithm for Global Maximum Power Point Tracking of PV Array Under Partial Shading Conditions

Photovoltaic (PV) array under partial shading conditions (PSCs) has several maximum power points (MPPs) on the power-voltage curve of the PV array. These points; have a unique global peak (GP) and the others are local peaks (LPs). This paper aims to study an improved version of a heuristic optimization technique namely, Invasive Weed Optimization (IWO) to track the global maximum power point (GMPP) of a PV array which is an important issue. The proposed improved IWO (IIWO) algorithm modifies IWO to speed up the convergence and make the system more efficient. In addition to study the effect of changing input parameters of IIWO on its performance. An overall statistical evaluation of IIWO, with standard IWO and Particle Swarm Optimization (PSO) is executed under different shading conditions. The simulation results show that IIWO has faster and better convergence as it can reach the GMPP in less time compared with other techniques.

Investigation of Partial Shading Scenarios on a Photovoltaic Array’s Characteristics

The purpose of this study is to investigate the impact of different partial shading scenarios on a PV array’s characteristics in order to develop a simple and easy-to-implement GMPP controller that tracks the PV array’s global maximum power point (GMPP). The P-V characteristic of the PV array becomes more complicated under partial shading, owing to the presence of many power peaks, as opposed to uniform irradiance conditions, when there is only one peak called the maximum power point. In fact, and according to an experiment conducted in this study, when a PV array is partially shaded, the P-V characteristic mostly presents two peaks, given the existence of only two levels of irradiance, one of which is called the global peak (i.e., the GMPP). Furthermore, the first peak is located at Vmpp1 (the PV array’s voltage corresponds to this peak), whereas the second is at Vmpp2. The proposed approach works by estimating the values of Vmpp1 and Vmpp2 using two equations in order to control the DC/DC converter of the PV system. The first equation is used when the GMPP is at the first peak, while the other is used when the GMPP is at the second peak. Several scenarios are simulated and presented in this paper to verify the accuracy of these equations. In addition, some conclusions are drawn to suggest a simple method for tracking the GMPP.

Optimal Hybrid PV Array Topologies to Maximize the Power Output by Reducing the Effect of Non-Uniform Operating Conditions

The photovoltaic (PV) system center inverter architecture comprises various conventional array topologies such as simple-series (S-S), parallel (P), series-parallel (S-P), total-cross-tied (T-C-T), bridge-linked (B-L), and honey-comb (H-C). The conventional PV array topologies under non-uniform operating conditions (NUOCs) produce a higher amount of mismatching power loss and represent multiple maximum-power-points (M-P-Ps) in the output characteristics. The performance of T-C-T topology is found superior among the conventional topologies under NUOCs. However, T-C-T topology’s main limitations are higher redundancy, more number of electrical connections, higher cabling loss, poor performance during row-wise shading patterns, and more number of switches and sensors for the re-configuration of PV modules. This paper proposes the various optimal hybrid PV array topologies to overcome the limitations of conventional T-C-T array topology. The proposed hybrid topologies are such as series-parallel-cross-tied (S-P-C-T), bridge-link-cross-tied (B-L-C-T), honey-comb-cross-tied (H-C-C-T), series-parallel-total-cross-tied (S-P-T-C-T), bridge-link-total-cross-tied (B-L-T-C-T), honey-comb-total-cross-tied (H-C-T-C-T), and bridge-link-honey-comb (B-L-H-C). The proposed hybrid topologies performance is evaluated and compared with the conventional topologies under various NUOCs. The parameters used for the comparative study are open-circuit voltage, short-circuit current, global-maximum-power-point (GMPP), local-maximum-power-point (LMPP), number of LMPPs, and fill factor (FF). Furthermore, the mismatched power loss and the conversion efficiency of conventional and hybrid array topologies are also determined. Based on the results, it is found that the hybrid array topologies maximize the power output by mitigating the effect of NUOCs and reducing the number of LMPPs.