Stand-alone power system

About: Stand-alone power system is a research topic. Over the lifetime, 8650 publications have been published within this topic receiving 192397 citations. The topic is also known as: Stand-alone photovoltaic power system.

Design and economics analysis of an off-grid PV system for household electrification

Abstract: This paper presents a study about an off-grid (stand-alone) photovoltaic (PV) system for electrification of a single residential household in the city of Faisalabad, Pakistan (31.42°N, 73.08°E, 184 m). The system has been designed keeping in view the required household load and energy available from the sun. The complete model for the sizing of complete PV system has been presented to determine the required PV power rating, battery storage capacity, size of charge controller and inverter to fulfill the required load. Using this model, the peak power and area of PV modules, capacity of battery backup, size of charge controller and inverter was calculated to be 1928 Wp and 12.85 m2, 9640.5 W h, 56.65 A and 1020 W, respectively. The economics evaluation using life cycle cost (LCC) analysis of the complete system has also been carried out. The LCC of the system was found to be PKR. 457,306 whereas the annualized life cycle cost (ALCC) was determined to be PKR. 31,963 yr−1, respectively. The unit electricity cost has also been calculated and was found to be PKR. 14.8 kW h−1. The results show that unit cost of electricity produced using off-grid PV system is lower than the unit cost charged in case of conventional electric supply to the residential areas. It is concluded that off-PV electricity is technically and economically viable technology for the electrification of residential applications.

Electric car drive system provided with hybrid battery and control method

Abstract: In an electric car drive system having a car drive motor powered by a mounted direct current power supply, a control system including a signal generating means is provided to generate signals which control motor speed. The direct current power supply is composed of a power battery having secondary cells connected to the motor and an energy battery formed by fuel cells connected in parallel to said power battery via an energy battery control switch. The electric car drive system is composed of a charge control means which charges the power battery using the energy battery if the charge of the power battery is below the specified value when said key switch is turned off, and suspends charging if the charge is equal to or greater than the specified value. A battery current and voltage control controls a voltage increasing circuit connected between the energy battery and the power battery based on the current or voltage of any one of the power battery, energy battery or motor and keeps the voltage of the direct current power supply within a specified range.

Economic and Efficient Voltage Management Using Customer-Owned Energy Storage Systems in a Distribution Network With High Penetration of Photovoltaic Systems

Abstract: The widespread installation of distributed generation systems is crucial for making optimal use of renewable energy. However, local distribution networks face voltage fluctuation problems if numerous photovoltaic (PV) systems are connected. Recently, energy storage systems that can be installed at commercial customers have been developed. This paper proposes a concept that solves the voltage fluctuation problem in distribution networks with high penetration of PV systems by using customer-side energy storage systems. The distribution network operator (DNO) is allowed to control the output of the energy storage systems of customers during a specific time period in exchange for a subsidy covering a portion of the initial cost of the storage system. The cost effectiveness of the cooperative operation for both customer and DNO is discussed by numerical simulations based on minute-by-minute solar irradiation data. Our results have clarified the possibilities of making voltage management more economical in distribution networks.

A Compact Digitally Controlled Fuel Cell/Battery Hybrid Power Source

Abstract: A compact digitally controlled fuel cell/battery hybrid power source is presented in this paper. The hybrid power source composed of fuel cells and batteries provides a much higher peak power than each component alone while preserving high energy density, which is important and desirable for many modern electronic devices, through an appropriately controlled dc/dc power converter that handles the power flow shared by the fuel cell and the battery. Rather than being controlled to serve only as a voltage or current regulator, the power converter is regulated to balance the power flow to satisfy the load requirements while ensuring the various limitations of electrochemical components such as battery overcharge, fuel cell current limit (FCCL), etc. Digital technology is applied in the control of power electronics due to many advantages over analog technology such as programmability, less susceptibility to environmental variations, and low parts count. The user can set the FCCL, battery current limit, and battery voltage limit in the digital controller. A control algorithm that is suitable for regulating the multiple variables in the hybrid system is described by using a state-machine-based model; the issues about embedded control implementation are addressed; and the large-signal behavior of the hybrid system is analyzed on a voltage-current plane. The hybrid power source is then tested through simulation and validated on real hardware. This paper also discusses some important issues of the hybrid power source, such as operation under complex load profiles, power enhancement, and optimization of the hybrid system. The design presented here can not only be scaled to larger or smaller power capacities for a variety of applications but also be used for many other hybrid power sources

Providing electricity access to remote areas in India: An approach towards identifying potential areas for decentralized electricity supply

Abstract: This study presents the results of a preliminary attempt towards identifying potential areas in India where provision of electricity through renewable energy-based decentralized generation options can be financially more attractive as compared to extending the grid The cost of generation of electricity from coal, hydro and nuclear power plants and also cost of transmission and distribution of electricity in the country have been estimated The delivered cost of electricity (generated in a coal thermal power plant) in remote areas, located in the distance range of 5–25 km is found to vary in a wide range varying from Rs 1 318 to 23114/kWh depending on peak electrical load and load factor The study indicates that renewable energy-based decentralized electricity supply options (such as micro hydro, dual fuel biomass gasifier systems, small wind electric generators and photovoltaics) could be financially attractive as compared to grid extension for providing access to electricity in small remote villages