Research On Substation Protection Scheme Based On Bay Level Protective Relays

With the development of large scale new energy and hybrid super/ultra high voltage interconnected power grid, and the concept of Energy Internet being proposed, the traditional three-section protection using local information is gradually exposed to its inherent drawbacks. The use of muli-source information has become a research focus which is able to improve and enhance the performance of traditional protection. Based on the research about the traditional protection system, this paper propsed a constitution scheme of substation protection based on the bay level protective relays, which utilizes the logic protection action signal to make the logical judgment on the substation protection. The proposed scheme is implemented and tested based on a practical project of Shendang in Jiaxing, Zhejiang.Proposed a constitution scheme of substation protection based on traditional protection system. First, upload the protection logic signal and switch state signal of the existing bay level protective relays to the substation center through the GOOSE network in accordance with the IEC61850 standard. Then, according to the protection action signal, the fault in the station can be identified rapidly and accurately by the substation center. Finally, issue the trip command through the GOOSE network to the intelligent terminal, and the fault will be cleared.Proposed a substation protection algorithm based on the logical judgment of the protection action signal uploaded by the bay level protective relays, including transformer protection logic, high voltage bus protection logic, medium voltage bus protection logic and low voltage bus protection logic. The protection logic uses the signal on both sides of the device being protected to carry out fault identification, and uses the remote backup protection action signal to check the fault identification results to eliminate the influence of the individual protection signal error. The protection logic is not dependent on each other, so the logic can be executed separately, and meets the requirement of test and maintenance in actual project.Based on the practical network of Shendang in Jiaxing, Zhejiang, firstly, build the power system model in RTDS simulation platform, and use the CBuilder to develop bay level protection module and substation protection module. Then, the real-time simulation test of the proposed substation protection scheme is carried out, which shows that the proposed scheme can accurately and reliably identify the substation faults.