Faults detection and mitigation in excitation control of synchronous machines in large-scale power grids

Abstract

This paper presents a new decentralised fault detection and mitigation system for excitation control systems used in synchronous generators in power grids. The system detects and diagnoses faults in the basic components of the excitation control systems with high accuracy and in almost real time using fuzzy set theory. Once a fault is diagnosed, a mitigation action follows, where the signal out of the faulty component is replaced by an alternative signal generated by the fault mitigation system. The mitigation action ensures that the field excitation voltage and thus the terminal voltage of the affected generator are controlled in a way that pre-fault stability of the grid is maintained. The accuracy and effectiveness of the proposed scheme are verified through case studies performed on the IEEE 30 bus test system.

Simulation and Test Bed of a Low-Power Digital Excitation System for Industry 4.0

“…Their operating characteristics can be expressed by the following equations: Ordinarily, a constant magnetic flux should be maintained for motors, and this can be achieved by maintaining a constant field current. Equation (2) shows that, when the motor output torque is greater than the load torque, the extra torque becomes an acceleration torque and pushes the speed of the motor. At the same time, the output torque increases when the armature current increases.…”

“…These are basically associated with many other critical social elements such as food production, water consumption, manufacturing, resource management, security, and environment. Currently, process system engineering is in a position where it can solve the most important problems associated with energy systems and mitigate their impact on all countries around the world [1][2][3].…”

A Cost-Effective Redundant Digital Excitation Control System and Test Bed Experiment for Safe Power Supply for Process Industry 4.0

“…Also, The defects in power system components have been a serious problem in modern power systems and many system errors caused by such defects were continuously reported in the last few decades [15][16][17][18][19]. Accordingly, the research on the ECS fault detection methods is being carried out actively as the previous research results [20][21][22][23][24][25][26][27] were drawn from the simple excitation system models. For instance, in the research result of [25], a static load was used as the load generated in the power system whereas a 3-phase full-wave rectifier was supposed to be the exciter.…”

“…A transducer defect detection and mitigation method adaptable to ECS was proposed in [26] where an IEEE ST2A model was introduced but the model did not have any over/under-excitation (Block 4 & 5, Figure 1) limiters which would play an essential role in the steady and safe operation of synchronous generators. The Authors' proposal of an excitation fault diagnosis and mitigation approach based on a Mamdani fuzzy inference is proposed in [27] but the parametric uncertainties have not been considered in the excitation system model. Additionally, the model's operation under the external influences/disturbances (i.e., transmission line defect, load variation, etc.)…”