IMPLEMENTATION OF A STAND-ALONE 3.5KVA POWER SYSTEM

ABSTRACT

Power failure and fluctuation in power supplied by the grid electricity supply companies in Nigeria have continued to linger, fuel marketers are taking significant portions of households’ and businesses’ incomes which they expend to power noise polluting generating sets which may eventually come with imaginable consequences on the health of its user. These problems gives a need to design a solar inverter system suitable for designated load requirements. The aim of this work is to design and install a 3.5KVA hybrid solar inverter system to provide a back-up and reliable power supply to a standard office apartment. In this work, eight sets of 270W monocrystalline solar panels is installed on the rooftop of an office apartment, these panels have four sets of two panels connected in series and each set connected in parallel. A 24V, 3.5KVA hybrid inverter is connected to a set of four 12V, 200Ah tubular batteries. The batteries are connected such that two sets of two batteries are connected in parallel and each of these sets are connected in series to achieve a 24V, 400Ah battery setup. The Solar panels make use of the hybrid inverters built-in 60A charge controller to charge up the batteries from the ambient sun light. Test and experiments carried out on the installed inverter system shows that the system meets the required design performance with an output voltage and frequency is 220V and 50Hz respectively and a Power efficiency of 90.64%. This can sustain steady output of 220-240 volts to external load for 8 hours or more. The duration depends on the summary of the wattage of the load throughout the usage period.