Adaptive Scheme for Minimal Load Shedding Utilizing Synchrophasor Measurements to Ensure Frequency and Voltage Stability

Abstract

This article presents a new scheme for load curtailment in the power system under critical contingencies that may pose a threat to the frequency and voltage stability of the system. The proposed scheme is based on a two-stage loadshedding strategy. In the first stage, disturbances have been classified based on the computed value of the disturbance power, and the load-shedding requirement in the system has been assessed based on the frequency stability, as well as dynamic voltage stability, conditions. The scheme assumes the availability of real-time data from a synchrophasor-based wide area monitoring and control system. A dynamic voltage stability criterion has been developed in this stage using a voltage stability risk index to assess the voltage stability in real time. Suitable locations for the load curtailments have been chosen according to the voltage stability risk index, which is calculated at each load bus. After the system attains transient stability, the second stage of the proposed scheme determines the optimal redispatching of generators for recovering the loads as much as possible, which had been curtailed in the first stage following the contingency. Performance of the proposed scheme has been tested on a 10-machine, New England 39-bus system, and the results are compared with a conventional under-frequency load-shedding scheme and an adaptive load-shedding scheme.

Micro-synchrophasor based special protection scheme for distribution system automation in a smart city

“…This ensures a reliable power supply to MC hospital campus and add on to the meticulous efforts taken by power system operations team for upgradation of power system protection and automation, in the journey towards smart Thiruvananthapuram city. [42]. The study assumes availability of data from PMU using which a dynamic voltage stability criterion i.e.…”

“…The study assumes availability of data from PMU using which a dynamic voltage stability criterion i.e. voltage stability risk index (VSRI) [42] is devised to analyze the voltage stability of system in real time. The VSRI at each load bus is used for deciding upon suitable locations for the load curtailments to mitigate voltage instability.…”

“…The VSRI at each load bus is used for deciding upon suitable locations for the load curtailments to mitigate voltage instability. The scheme using VSRI was chosen for study as comparison has been made with conventional under frequency load shedding scheme as well as another load shedding scheme in [42]. As in [42], the New England 10-machine 39-bus system shown in Fig.…”

“…The scheme using VSRI was chosen for study as comparison has been made with conventional under frequency load shedding scheme as well as another load shedding scheme in [42]. As in [42], the New England 10-machine 39-bus system shown in Fig. 17 has been chosen for testing VSI derived in the present study.…”

A New Optimal Under-frequency Load-shedding Method Using Hybrid Culture–Particle Swarm Optimization–Co-evolutionary Algorithm and Artificial Neural Networks

“…It is to be noted that the two first methods are not effective in practice, but the third not only has a remarkable effect on system stability but also can be implemented with under-frequency relays capabilities. In [8,9], two different load-shedding approaches with the combination of frequency and voltage stability criteria and using df/dt were reported. In [10], a novel approach using the second derivative of the frequency as a source of information for the forecast of the frequency trajectory to improve the UFLS adaptation capability was proposed.…”