Research Of Operation And Maintenance Technology Based On IEC61850 In Secondary System Of Intelligent Substation

With the rapid development of smart grid construction, the substations under the jurisdiction of Hangzhou power Supply Company are rapidly entering the intelligence era. Intelligent substation has become the mainstream direction for construction and improvement of substations, however there are also many problems to be solved in operation and maintenance. For example, Safety measures for the substation secondary circuits are very important to ensure the security of operation and maintenance. Safety measures for the secondary system in conventional substations are based on the theory of apparent electrical breakpoint, which cannot be used in intelligent substations. State Grid Corporation of china is gradually promoting maintenance without power-off that is mainly based on on-line monitoring and live monitoring techniques. At the same time, evaluation index on the power supply circuit in addition to equipment has been added to the electric benchmarks. Therefore, the traditional maintenance mode of relay protection which is widely used now and demands to cut off primary equipment is facing severe challenges. Condition-based maintenance of substation primary equipment makes it difficult for the first verification of the secondary system that shall be conducted one year after operation to acquire the power-off condition. In consequence, the problem often appears that equipment cannot have verification in time and runs without being verified.In order to solve these problems, this dissertation studies the structural characteristics of intelligent substations, and puts forward several improvement techniques and methods for operation and maintenance of intelligent substations. Aiming at the safety measures for the secondary circuits in intelligent substations, this paper firstly analyzes the secondary circuit isolation technologies applied for intelligent substations with a comparison among them, and proposes implementation principle of dual-configuration GOOSE safety measure and other safety measures. The feasibility of intelligent substations using relay protection maintenance without power cut is analyzed on the basis of using proper secondary safety measures. Secondly, this paper introduces safety measures and commissioning methods of maintenance without power cut with real examples. This paper presents the first-check type acceptance of intelligent substations, which improves acceptance quality of the secondary system, and also solves the problem that it is difficult for the first verification of the secondary system that conducts years after operation to get power off condition.By consistently using in the substations under jurisdiction, these operation and maintenance techniques and methods as mentioned above are gradually improved, and their effectiveness and feasibility are verified. The safety measures for the secondary circuits of intelligent substations are applied as well as verified in the maintenance work of intelligent substations, which provides reliable security isolation for the secondary circuits. Relay protection maintenance of intelligent substations without power cut is conducted by means of turning off single set of protection device in turn. In this way, the power-off time caused by protection maintenance can be significantly reduced, and the reliability of power supply can be remarkably improved. As a result of practical verification, the stability of totally-verified intelligent substation secondary system through first-check type acceptance is guaranteed. The first-check type acceptance for intelligent substation relay protection enhances the completion and acceptance quality of substation projects, dramatically decreases the defect rate after the relay protection equipment putting into operation, reduces loss caused by equipment defects, and improves the operation and management level of relay protection equipment.