Loss of Excitation (LOE) Protection of Generator by R-X Schemes

International Journal of Research and Scientific Innovation (IJRSI) | Volume V, Issue III, March 2018 | ISSN 2321–2705

Loss of Excitation (LOE) Protection of Generator by R-X Schemes

Vishal J.Patel¹, Nilaykumar A.Patel²

  ^{1, 2} M&V Patel Department of Electrical Engineering, Charusat University of Science & Technology, Nadiad Petlad Highway 139,Changa, Gujarat, India

Abstract–Generator is the most important equipment of our power system.when the generator fault occurs the effected entire in power system. So the generator protection is needed in power system protection. When the generator LOE loss of excitation field fails then the generator speed also increase and generator works on induction generator and instead of delivering reactive power it absorb the reactive power from the system. so, the generator protection is needed in power system. Different protection will be used in generator protection. In this paper focus on RX scheme for generator excitation protection.

Keywords -Generator protection loss of excitation protection RX scheme , active and reactive power of the system.(1)

I. INTRODUCTION

The generator Loss Of excitation (LOE) is a very common fault in synchronous machine and can be caused by short circuit of the field winding, unexpected field breaker open or LOE relay mal operation. the Loss-of-excitation (LOE) protection of synchronous generator is becoming more and more important to the generator protection with the development of power system.(2) This is because LOE is a common fault for synchronous generators, which may cause serious damages to generators and the interconnected power systems. When loss of excitation occurs its speed will increase and syn. Generator works on induction generator. Generator taking reactive power from the system instead of supplying it. This may cause severe damage to the generator itself and to the power system to which the generator is connected.

Generator loss of excitation can be caused by short circuit of the field winding, unexpected field breaker opening and a failure in the excitation system. So the R-X Schemes of generator field failure protection will be used. For these reasons, LOE protection schemes are required to detect the LOE condition as rapidly as possible while remaining insensitive to the external faults and other system disturbances describes the characteristics of impedance measurement scheme, which is the most common LOE protection scheme. R-X schemes is generator terminal impedance measurement on R-X plane.

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