HYBRID INVERTER POWER SYSTEM

The main purpose of the project was to design a 3.5KVA inverter which makes use of both solar and mains or grid supply for charging the batteries. This is to reduce the frequency of power outages experienced in our homes and businesses. The project was carried out with the use of two 12V batteries connected in series to give a total of 24V DC which would serve as input for the inverter when on inverting mode and give an output of 220V AC for household appliances. Incorporated within the inverter was load control features, such that when the inverter stops charging and starts inverting, at a particular battery level set by the user, the heavy loads would be cut off while supply of power to the light loads continues. But when critical battery level is reached the light loads are also cut off and the inverter shuts down. This was done using Microcontroller in controlling relays which either powers on the load or cuts off the load when the battery is low. The proposed inverter design has two outputs through which load management was achieved. One of the outputs is designated to light loads and the other to heavy loads. The Microcontroller DSPIC30F4012 controls the load stage which can be programmed through the keypad to monitor the output power to the loads in output one and two, to ensure they do not draw power beyond the limits programmed by the user. To achieve this, the Microcontroller cuts off either of the outputs which exceed the set limit. The project was successful and the test results obtained was satisfactory. The inverter's operation was consistent with the design and the desired control of power consumption and power management was achieved.