Stand-alone Solar Photovoltaic Power Research Articles

Design methodology and implementation of stand-alone solar photovoltaic power system for daily energy consumption of 9.16 kWh

This stand-alone solar photovoltaic power system was designed to power a daily energy consumption of 9.16 kWh reliably, by means of photovoltaic only. The design involves different components whose capacities depend on 9.16 kWh daily energy consumption and 1-day autonomy, including several factors that determine the choice of selection. After implementation, the system was put to the test for two days to ascertain the design validity and check if it would be able to sustain the daily load demand for 24 h without failure. The results reveal that the design methodology employed for the stand-alone system in this study is accurate and reliable because the system was able to power the load interminably for 34 h, with a resulting 0.6% DoD at the end of the test. This was due to the complete energy balance that the design methodology offers. Day 1 shows that the overall PV array power was 208% higher than the daytime load power and 61.2% higher than the overall daily load power. While Day-2 shows the overall PV array power to be 130% higher than the daytime load power and 56.3% higher than the overall daily load power, The energy balance between PV array, battery, and load size was completely and sufficiently achieved on both days, as the highest depth of discharge recorded during the test was 48.7%. The study reveals that through a complete energy balance between PV, battery, and load size, a standalone PV system can reliably sustain daily energy demand. It aims to design a stand-alone PV system capable of reliably sustaining daily energy demand without the need for long days of autonomy, so as to help prevent failures in solar PV projects that come as a result of inappropriate sizing, planning, and a lack of technical know-how.

An intelligent converter and controller for electric vehicle drives utilizing grid and stand-alone solar photovoltaic power generation systems

In this study, a battery energy management system for electric vehicle (EV) applications is proposed with a standalone photovoltaic (PV) source and controlled based on the availability of grid, PV source, load consumption, and energy stored in the battery. This paper proposes a single-ended primary-inductance converter (SEPIC) DC-DC converter for charging the battery through the utility and PV source that provides good load regulation. The bidirectional nature of the proposed DC-DC converter provides the charging and discharging of the EV battery in the succeeding modes of operation, i) grid-tied charging, ii) PV-tied charging, iii) discharging to the load in the absence of utility and PV source, and iv) regenerative braking. An improved perturb and observe-based maximum power point tracking (MPPT) algorithm is proposed to track the maximum power from the PV source. In addition, to handle the four modes of operation, a dedicated controller is also proposed. Firstly, the proposed system is validated using MATLAB/Simulink software by considering different operating conditions, and the performance is compared with the traditional MPPT algorithms. Finally, the effectiveness of the suggested system is validated through an experimental prototype. The result proved the superiority of the converter and controller over the traditional systems.<div align="center"> </div>

Simulation and Experimental Investigation of a Smart MPPT based Solar Charge Controller

ABSTRACT This paper presents the concept of a maximum power point tracking (MPPT)-based solar charge controllers (SCC) for charging a battery in stand-alone solar photovoltaic (SPV) systems. An SCC is a battery charge regulator that is connected in between the SPV panel and the battery, the primary purpose of the SCC is to regulate the charging of the battery so that it charges correctly and more importantly it is not overcharged. Nowadays mainly two types of SCCs are in use, one is the pulse width modulation (PWM)-based SCCs and the other one is MPPT-based SCCs. Although PWM-based SCCs may get the job done but they have very low efficiency as compared to MPPT-based ones and thus waste a lot of SPV power. This fact has been analyzed in our report by executing the simulations for both the charge controller types and the efficiency of PWM was found to be only 65% where as that of the MPPT based is 94%. In this prototype model, we have implemented MPPT-based SCC along with one Wi-Fi module for monitoring the battery voltage, current, PWM pulses and battery status on smartphone. The user also gets notified about the battery status, whether the battery is charging or it is over charging. If the SPV voltage is more than 12 V the relay disconnects the battery from the SPV cell and a notification regarding this is given to the user. All these features make the prototype versatile and user-friendly.

Design Analysis of 7.5KW Stand Alone Solar Photovoltaic Power System for an Intermediate Household

Aim: Design Analysis of 7.5KW Stand-alone Solar Photovoltaic Power System for an Intermediate Household.
 Methodology: A design analysis of standalone 7.5KW PV system was carried out using PV modeling equations based on load estimated. The analyzed data of the solar photovoltaic components was used to determine the estimated output power of 7.5KW. Therefore, a number of modeling equations and methodologies for designing a PV system based on application have been developed and simplified in order to ensure the optimum performance of the system. The analyzed solar powered 7.5KW system was achieved by designing 24 solar panels of 335W each, 16 deep cycle battery of 200A each, and a pulse width modulation (PWM) charge controller of 60A to monitor the output of the battery for safety operation. The battery will be connected to the inverter circuit (DC-AC) to generate 220V alternating current in its output via a step-up transformer. In this paper, design analysis of a standalone PV system enables of producing power to a household with approximate consumption of 7.5KW was conducted. 
 Results: The standalone PV system along with the cost implications was analysed and designed. In this analysis a sequential design plan of an independent standalone solar powered photovoltaic structure was analysed and overviewed to supply continuous and uninterrupted power to a typical utility with maximum power consumption of 7500W (7.5KVA). The calculated/computed values of all the components yield a result that can serve the purpose. Based on the design analysis, the result implies that the estimate consumption of 7.5KW in a day requires 24 PV panels of 335 Watts each, 16 (12V, 200Ah) batteries, 10KW inverter, (12V, 60A) charge controller and copper wire of cross-sectional area (1.688mm2) for installation. 
 Conclusion: In Nigeria, to generate a solar power of 7.5KVA requires almost $15,585.70 which is equivalent to N 5,965,426.66.

Single Stage Autonomous Solar Water Pumping System Using PMSM Drive

This article presents a single stage standalone solar photovoltaic (SPV) array fed water pumping system using a permanent magnet synchronous motor (PMSM). The vital contribution of this work includes: 1) development of the novel modified vector control, which improves the torque response of the system, 2) development of a novel single stage variable step size incremental conductance technique, which provides a fast maximum power point tracking and eliminates the need of intermediate stage dc–dc converter, and 3) introduction of SPV power feed-forward term, which accelerates the overall response of the system under dynamic conditions. This system includes a SPV array, a three-phase voltage source inverter (VSI), a PMSM and a pump. The SPV array converts solar energy into electrical energy. The VSI acts as power processing unit, which supplies desired currents to drive the PMSM. As the PMSM rotates, the pump coupled to the motor accomplishes the objective of water pumping. This system is modeled and simulated using MATLAB/Simulink with available simpower system toolbox and the behavior of the system under varying atmospheric conditions are validated experimentally on a developed prototype in the laboratory.

Self-sufficiency of 3-D printers: utilizing stand-alone solar photovoltaic power systems

A self-replicating rapid prototyper (RepRap) is a type of 3-D printer capable of printing many of its own components in addition to a wide assortment of products from high-value scientific or medical tools to household products and toys. There is some evidence that these printers could provide low-cost distributed manufacturing in underprivileged rural areas. For the most isolated communities without access to the electric grid, a low-cost alternative energy is needed. Solar energy can be harvested through a stand-alone photovoltaic (PV) power system specifically designed to match the needs of the RepRap. The voltage and current requirement for the printer demands the use of buck along with a bidirectional DC converters to ensure proper operation. This paper provides the design for a stand-alone PV—lithium ion battery power system with an efficient controller. Robust and agile PI controller schemes are utilized to efficiently maintain the distribution of energy through the power system. The system was defined with ordinary differential equations, simulated and tested for two operational conditions in MATLAB/Simulink. The results showed that the controller developed operates the system in a stable condition and the simulation shows steady acceptable behavior that makes this system highly suitable for hardware implementation.

Proposed generalized models for estimating the reliability of a stand-alone solar photovoltaic power system

New mathematical models for the reliability of a stand-alone solar photovoltaic power system (SPV) are proposed in this paper. One of the important reliability indices is the loss-of-load probability (LOLP), so its dependence on the design parameters is modelled. The special role that the battery storage can play to fulfil the desired reliability level (RL) is clearly demonstrated. For a given size of solar cells array (SCA), an econometric model of LOLP is developed to yield the incremental change in the system's total lifetime costs on modifying the LOLP level. The effect of the failure rate of each system component on the SPV reliability level has been estimated and is fully discussed. The behaviour of the SPV reliability level with SCA tilt angle and series-parallel configuration is established under the prevailing working conditions. The significance of the relationship between the preventive maintenance schedule for each of the system components and its reliability is analysed, resulting in a new chart that enables schedules which yield the required system reliability to be planned directly.