The design makes use of power from a present transformer to energy a fault indicator, shops power in a supercapacitor, and features a backup battery.
The TIDA-01385, reference design from Texas Devices (TI) encompasses a circuit that captures power from a present transformer to energy the fault indicator’s system load, whereas storing surplus power in a 2.7 V supercapacitor. A major Li/SOCl2 battery serves as a backup energy supply, extending the fault indicator’s operation when the facility grid fails. Able to dealing with enter currents starting from 3 mA to 2 A, this Design delivers a secure 3.6 V output to the system load inside 2 seconds of connecting the present transformer. The design is particularly suited to fault indicator purposes.
A fault indicator is a tool utilized in electrical energy distribution networks to detect and sign fault situations. By pinpointing the precise part of the community experiencing a fault, these indicators assist scale back operational prices and decrease service interruptions. To quickly determine the kind and site of faults, trendy fault indicators are designed to report operational knowledge from the facility community and transmit this info to an information concentrator through low-power wi-fi communication when essential.
The facility for the fault indicator is equipped primarily by means of power harvesting units, with a major battery serving as a backup. Typical power harvesting sources embrace present transformers (CTs) or photo voltaic cells. For the reason that power output from a CT is dependent upon the present flowing by means of energy strains, and photo voltaic cell output varies with daylight situations, an power buffer comparable to a supercapacitor or rechargeable battery is critical to make sure a secure energy provide. The reference design presents a circuit that harvests power from a CT to cost a supercapacitor, offering a secure energy supply for the system load.
The design takes energy from the secondary facet of a present transformer (CT), with a most enter present of two A and a typical minimal present above 3 mA, relying on the system load. The AC enter from the CT is transformed to DC utilizing a full-bridge rectifier. When the supercapacitor is totally charged, an overcharge safety circuit diverts extra present to floor. As soon as the voltage drops under a sure stage, charging resumes. The charging circuit solely permits the supercapacitor to cost when the enter voltage is above 1.6 V, making certain sufficient energy for the system even when the supercapacitor begins at zero voltage.
A monitor circuit helps handle the supercapacitor’s cost stage to stop overcharging. A lift converter will increase the voltage to a gradual 3.6 V to energy the system load, which additionally helps keep away from draining the battery throughout regular situations. The backup battery is related by means of a Schottky diode and supplies energy when the grid fails and the supercapacitor is empty. This setup ensures a secure and dependable energy provide for the fault indicator system.
TI has examined this reference design. It comes with a invoice of supplies (BOM), schematics, meeting drawing, printed circuit board (PCB) structure, and extra. The corporate’s web site has extra knowledge in regards to the reference design. To learn extra about this reference design, click on right here.
