Research and Implementation of SCD Precision Decoupling in Intelligent Substation for Single Equipment Replacement

In the process of reconstruction and expansion of intelligent substation, it is difficult to accurately define the influence scope of SCD file upgrade. In the wake of each modification of SCD file, all configuration information contained in SCD needs to be re-verified, which greatly increases the workload of debugging, operation and maintenance of intelligent substation. Via decoupling SCD files, the problems of modification and re-verification of SCD files in the reconstruction and expansion stage can be tackled. In this paper, SCD precision decoupling method for smart substation with single equipment replacement is proposed, which makes SCD decoupling work more detailed, adaptable to various expansion and technical transformation of substation. The decoupling of SCD is refined from logical structure to physical link level, and the decoupling range of SCD is precisely determined, so as to minimize the modification and reverification range of SCD files and reduce the change risk caused by SCD modification.

Smart substation network quality monitoring and fault prediction

The smart substation communication network is the basis for information sharing of various devices in the substation. Its operation status has an important impact on the safe operation of the substation and even the power grid. Therefore, real-time status monitoring of the smart substation communication network is becoming more and more important. Aiming at the problems of single dimension, insufficient real-time performance and manual fault analysis in existing substation communication network state monitoring technology, this paper proposes a method of smart substation communication network state monitoring and fault prediction based on network communication quality. This paper uses switch ACL technology and coloring technology to obtain communication quality indexes such as bandwidth utilization, delay, and packet loss rate in real time; based on a multi-dimensional evaluation algorithm, a comprehensive evaluation model of network communication quality is constructed; the model of the relationship between abnormal network communication quality and failures is established. Finally, real-time monitoring of network communication quality and fault prediction are realized. The application analysis in a typical 110 kV substation shows that this method can effectively evaluate the network communication quality and accurately predict failures, and can guide operationer and maintenaner to quickly restore the normal operation of the communication network.

Electronic Current Transformer Defects Statistical Analysis of Intelligent Substation

In order to master operation status of the electronic current transformer(ECT), application investigation and defects statistical analysis were conducted on ECT of 110(66)kV~1000kV applied in smart substation of the State Grid Corporation of China(SGCC). The defect location, defect cause and defect type of ECT with different principles are analyzed. The results indicate that the defects of ECT are mainly concentrated in the acquisition unit, the defect rate is closely related to the reliability of electronic components, the technical level, production process and quality control of the manufacturer. In view of the typical defect analysis, the corresponding solution measures are put forward to provide reference for the subsequent research and application of ECT.

An improved simulated load test system

A miniaturized analog load-checking relay protection test device is developed in this paper, in which a high-precision wireless phase volt-ampere test device is configured. This device, characterized by intelligence and ease of operation, realizes the detection of the transformation ratio, polarity, phase, etc. of the secondary wiring of the transformer in the smart substation merging unit and the conventional substation. It meets the testing requirements of smart substations, and can test bus differential protection, line protection, and various protections such as main transformer differential.

Reliability Evaluation for Cyber-Physical Smart Substation

Smart substation is the key part of smart grid. The reliability of smart substation is extremely important to the safe and stable operation of the smart grid. Smart substation is a cyber-physical system (CPS). Hence, this paper conducts reliability evaluation study for smart substation from the perspective of CPS. Firstly, the basic reliability indices of cyber and physical elements of smart substation are presented. The reliability index of one cyber element takes into account the reliability factors of data leakage, tampering, loss and delay, etc., on the cyber side. Then, the cyber-physical interactions of smart substation are analyzed. It is concluded that the effect of the cyber side and cyber-physical interactions on the reliability of smart substation is reflected in the effect of measurement and control messages on circuit breaker operation. And, the new reliability indices considering cyber-physical interactions are proposed. Furthermore, the MALI-hybrid method, which combines the Monte Carlo method, analytical method, Latin hypercube sampling method, and important sampling method, is presented for evaluating the reliability of smart substation. Finally, the rationality of the proposed reliability indices, the efficiency, and correctness of MALI-hybrid method are verified by case studies.

Prospective Smart Distribution Substation in Bangladesh: Modeling and Analysis

Being one of the fastest-growing economies in the world, Bangladesh needs to upgrade its electrical network and aim to reduce dependency on fossil fuel-based energy. For the aging and ever-expanding power network, it is necessary to have a smart substation in order to provide reliable, affordable, and sustainable electrical power. As Bangladesh is looking to integrate Distributed Generation (DG) in the power system, it is high time to think about integrating a smart distribution substation into its power network. In this paper, an investigation of the current power generation structure of Bangladesh was conducted and is described. The major focus was given to the upgradation of the existing substation and distribution setup of Bangladesh by providing suitable architectures, technologies, and communication protocols. Detailed studies of Bangladesh’s prospects to incorporate the new technology and renewable energy into its power network are discussed. ETAP was used to simulate the prospective system to show the feasibility of the prospective smart distribution substation in Bangladesh’s power network.