Design of microcontroller based multi-functional relay for automated protective system

Abstract

This paper presents the design and implementation of a microcontroller based multi-functional relay that can protect the equipment against over-current, over-voltage & under voltage. Provision for settings of over voltage, over current and under voltage limits is provided. Simulations are carried out using proteus eight (SP4) platforms and hardware prototype with ATMega328 as core controller is built to validate the operation of the microcontroller as multifunctional numerical relay. Index Terms--Arduino Uno board, ATMega328, faults, micro controller, over current relay, proteus 8 professional). I. INTRODUCTIONhe reliability and security electrical supply is an important factor in modern society. However increasing complexity of power systems makes it difficult for protection operation to achieve these objectives. Nevertheless, numerical relays are able to improve the protection operation significantly. The relays are capable of performing complex processing faster and with higher accuracy [1].Protection relay is a device which by means of measuring power system quantities (currents and voltages) and processing them through its internal logic, has the capacity to control the operation of a circuit breaker. The internal logic allows the relay to initiate a tripping sequence when anomalous conditions arise within the power system. With regard to their construction three types of relays can be distinguished: electromechanical, static and digital. In electromechanical relays, the actuating force is created by electromagnetic interaction. Static relays are based on analogue electronic components such as diodes, transistors, capacitors, etc. whereas numerical relays have their logic implemented in software and microprocessor technology. Some relay designs combine the static and digital technology. This paper concentrates on the analysis of digital relays. A digital relay consists of the following main parts: microcontroller, analogue input system, digital output system and independent power supply [2]. Figure 1 presents a simplified block diagram of a digital relay. The National Electrical Code defines over current as any current in excess Gandi ramarao ,Sateesh K Telagamsetti, PG students, V S Kale, Associate Professor are with the

Multiagent System-Based Adaptive Numerical Relay Design and Development: Part I - Firmware

“…These microprocessorbased relays possessing various features and capabilities can effectively detect and handle faults in the power system for various protection features such as overcurrent, overvoltage, undervoltage, distance protection, differential protection, and more. [1] To facilitate efficient data exchange among protection devices and remote monitoring systems within electrical substations, several communication protocols have been developed, such as Modbus, DNP3, IEC 60870, and the IEC 61850 standard [2].…”