Transient fault information based multifunctional integrated IED in smart substation

Abstract

A transient fault information based IED integrating protection, fault location, fault record, measurement and control functions for transmission line is proposed in this paper. IED hardware scheme adopts multiple CPU distributed structure, and includes mainly the following modules: process level communication module, protection module, fault location and record module, measurement and control module, station level communication module and a MMI module. Transient fault information utilization is illustrated in detail, which mainly reflected in the protection module and the fault location and record module. Some key techniques are used to meet the smart substation development requirements. The multifunctional integrated IED can apply in the existing smart substations, improve protection performance and fault location precision, reduce equipment cost and operation and maintenance cost.

Identification of broken conductor faults in interconnected transmission systems based on discrete wavelet transform

“…This calculation involves multiplying the first detail coefficient (D1) of the aerial mode for both voltage (D1 Vr ) and current (D1 ir ) at each SSU. The resulting value is derived using the following equation [33,34], (2N presents the samples in a window, n denotes the sampling order within a sliding window that covers a complete cycle).…”

Study of Ultra-High-Speed Protection of Transmission Lines Using a Directional Comparison Scheme of Transient Energy

“…6 2) Effect of Data Window: In order to improve the sensitivity, the data window should be set appropriately according to (14) regarding a certain line length. Obviously, a much shorter data window leads to fewer samples, for example, only one or two samples left, which will make the results easily influenced by disturbances.…”

“…3) Effect of the length of lines: Another impact on the data window is the length of the lines as shown in (14). A large number of simulation results show that the number of samples within the data window should be no less than 4 to ensure the sensitivity even under the most serious fault scenarios.…”

“…Therefore, if the line is too short, the sampling rate should be proportionally increased to guarantee at least 4 samples within the data window. If the line is too long, say 600 km, the data window will be 4 ms according to (14), which is adverse to the operation speed of the protection. In order to speed up the operation, the data window is limited to 2 ms for very long lines and simulation results show that it still has high sensitivity.…”

“…Otherwise, it is an external fault.Since the calculation of the algorithm does not require great computational effort, the corresponding time consumption can be neglected. If the length of line PM, MN and NQ is 100 km, 300 km and 400 km, respectively, we can set the data to(14). Let us consider a very close-up fault at the relay R M .…”