Hardware Development For Autosynchronization Of Alternators

Abstract

Synchronization of alternators require three conditions to be satis ed - identical phase sequence, identical voltages both in magnitude as well as phase and frequency between the incoming machine and busbar. If these conditions do not match at the time of breaker closing on two sides of the generator circuit breaker, the power system expe- riences transient and generator may get damaged due to heavy circulating current at this instant. Automatic synchronizers ensure that a generator synchronization with the utility is achieved without causing disturbances. The automated synchronization is aimed to match the essential conditions by design- ing proper hardware and interfacing it with software.This avoids judgement based manual decision making. By considering a typical case system of small capacity al- ternators, the dissertation work is focused separately on the development of suitable hardware topology so as automatic and smooth synchronization of an alternator can be achieved. Two synchronous generators are to be paralleled automatically, at suit- able instant of time using developed hardware unit and proposed algorithms (The software part is not covered in this report). In case of non-matching conditions, the hardware alongwith software is expected to change the parameters, so that the con- ditions are met. The project is intended to make realization of safe and automatic synchronization process.The report also brie y discusses the traditional methods of synchronization of alternator. As a part of hardware development process, the spe- ci c area of work can be enlisted as below: 1. Sensor selection for power signal derivation 2.Design of signal conditioning circuits for frequency and voltage measurement e.g. active low pass lter, zero crossing detector and uncontrolled bridge recti er. 3.Veri cation of designed signal conditioning circuits through simulation in Or- CAD Capture software. 4. Design of circuitry for control of terminal voltage and frequency of alternator. 5. Veri cation of designed circuitry for control of terminal voltage and frequency of alternator by simulation in OrCAD Capture software . 6. Fabrication of signal conditioning circuits, control circuits, gate driver circuit and DC power supply. 7. Experimental performance evaluation of all fabricated circuits, individually as well as in interfaced condition with PIC16F877A microcontroller for considered typical case system and test conditions.