Research on Implementation Scheme of Local Bay Control Unit (BCU) Installation

An implementation scheme of local BCU installation is introduced in this paper. The BCU is divided into two parts in this scheme, namely, the fundamental BCU and auxiliary BCU, in principle, the former one includes measurement, position acquisition of circuit breakers and isolators and control function, the signals of this part can be standardized, but at present, for the differences of primary equipment, the pressure blocking and binary input and output (BIO) acquisition (BIO) are hard to be standardized, so the signals of this part are acquired by the auxiliary BCU and directly sent to station control level through MMS network. The scheme effectively solved the problems of large quantity of binary input and binary output and the different binary input quantity of primary equipment.

1. Introduction

Local protection is the development direction of relay protection in the future. The relay protection device does not rely on the merging unit and the intelligent terminal any more and can be installed outdoors near the corresponding bay. The intermediate links are simplified by using cable to realize sampling and tripping, so the speed and reliability of the protection are effectively improved. At present, the some literatures have also put forward the local implementation schemes of secondary devices, such as line protection, main transformer protection, busbar differential protection, disturbance and fault recording system and so on, and compare the application schemes of local protection, and explore the system network architecture after the total secondary equipment is installed locally in the substation. Local installation of relay protection device has been put into service in a number of substations. On the basis of this research and practice, it is necessary to study the local scheme of various services to make sure that they can reach the overall optimal solution of local protection substation.