An Adaptive Protection for Radial AC Microgrid Using IEC 61850 Communication Standard: Algorithm Proposal Using Offline Simulations

Abstract

The IEC 61850 communication standard is getting popular for application in electric power substation automation. This paper focuses on the potential application of the IEC 61850 generic object-oriented substation event (GOOSE) protocol in the AC microgrid for adaptive protection. The focus of the paper is to utilize the existing low-voltage ride through characteristic of distributed generators (DGs) with a reactive power supply during faults and communication between intelligent electronic devices (IEDs) at different locations for adaptive overcurrent protection. The adaptive overcurrent IEDs detect the faults with two different preplanned settings groups: lower settings for the islanded mode and higher settings for the grid-connected mode considering limited fault contributions from the converter-based DGs. Setting groups are changed to lower values quickly using the circuit breaker status signal (XCBR) after loss-of-mains, loss-of-DG or islanding is detected. The methods of fault detection and isolation for two different kinds of communication-based IEDs (adaptive/nonadaptive) are explained for three-phase faults at two different locations. The communication-based IEDs take decisions in a decentralized manner, using information about the circuit breaker status, fault detection and current magnitude comparison signals obtained from other IEDs. However, the developed algorithm can also be implemented with the centralized system. An adaptive overcurrent protection algorithm was evaluated with PSCAD (Power Systems Computer Aided Design) simulations, and results were found to be effective for the considered fault cases.

IEC 61850-Based Centralized Protection against Single Line-To-Ground Faults in Ungrounded Distribution Systems

“…Assuming that the fault resistance ranges up to 5 kΩ, it is possible to determine V T 0 and m I TF 0 using (6) and (8), respectively. The threshold value for the zero-sequence angle difference m θ TF 0 is also determined by (6) and (8). Note that the zero-sequence angle difference is independent of the fault resistance, as indicated by the relationship between 4 V R 0 and 4 I R 0 own in Figure 3b.…”

Improved Adaptive Protection Scheme Based Combined Centralized/Decentralized Communications for Power Systems Equipped With Distributed Generation

“…The proposed method depends on using two directional relays in each feeder to isolate the feeder from both sides because As a common protocol, the IEC 61850 standard enables the integration of all protection, control, measurement, and monitoring functions [45].…”

Protection of Future Electricity Systems

“…While in the past its practical application was not perceived as critical and was also limited by technological constraints, the development of numerical multifunctional relays accompanied by digital communications, as well as increased system-fault-level variability, has enabled adaptive protection to progress to practical applications. In this issue, we include two papers [1,2] which propose adaptive solutions for both high-voltage transmission systems and distribution-level microgrids.…”