In recent days the application of micro controllers are increasing in electrical equipment protecting devices. Electrical systems are allowed to operate without any proper control system, so keeping this in mind we implemented a “Load monitor and Breaker with Digital Display using Microcontroller “ to protect the electrical systems from over currents.
The basic requirements of the protecting device are to monitor the changes in the current, voltage, frequency of the power system. For that we make use of micro controller in sensing the varying conditions and a protective relay is operated for protecting the network from un wanted over currents.
Youtube video link to view block diagram
The over current protection system uses an PIC micro controller, whenever the current in the main lines crosses a particular value the micro controller causes the circuit breaker to trip the circuit.
So firstly we need to monitor the load current so for that we use a current transformer whose primary is connected to the load terminals and its output terminals are converted into dc by using an rectifier and filter and it is converted in to digital pulses by the A/D converter, and then this digitalized pulses is fed to the micro controller, if this signal crosses the normal value it trips the circuit by passing signals to the relay circuit.
Download Load monitor and Breaker with Digital Display using Microcontroller Project Report
Hardware of the protective system:
The hardware i.e. the main components of the proposed system are,
- Sensing circuit – sensing circuit included current transformer i.e. current sensor, relay and circuit breaker.
- Control circuit – PIC micro controller interfaced with the secondary of the current transformer.