Load Sheddingtechniques For System With Cogeneration: A Review

Abstract

In developing countries a large demand of power will be seen in future. It is essential to maintain power continuity and reliability. Contingencies like fault occurrence and generated power and load demand imbalance causes system frequency instability. Load-shedding is the ultimate solution to restore system frequency and ensure availability of electrical power to critical loads in the plant. This paper presents a review of traditional adaptive and computational intelligent load shedding scheme. A comparison of these entire schemes with corresponding advantages and disadvantages is summarized.

An adaptive decentralized under voltage load shedding in distribution networks

“…The author in Reference 3 mentions the lack of information on magnitude of disturbances, unable to estimate the actual value of power imbalance, shedding the fixed amount of load during disturbances, is not suitable for the modern and complex power systems. The author in Reference 22 noted that on conventional scheme the voltage thresholds do not differentiate between the buses that feed loads whatever their priority or importance and finally large simulation and transient stability studies required as mentioned in Reference 25. The preset thresholds remain the same even after load shedding has been done.…”

“…These techniques offer some advantages over conventional UVLS, and offers more robustness and flexibility. The authors in Reference 25, for example, summarized some intelligent UVLS characteristics: it reflects true status and loading conditions for the load to be shed, their error is usually minimized, the load shedding priority list is updated and subcategorized in critical and noncritical loads. In addition, in Reference 26 the authors finds that intelligent techniques has the ability to find optimal load shedding scheme, more efficient when applied to modern and complex power systems but it do not guarantee to adapt with a combination of frequency and voltage instabilities in the system.…”

“…Previous works as References 3,25 summarized the specifications of an adaptive UVLS whatever its different methodologies, so they believed that adaptive UVLS accurately determines the amount of load to be shed.…”

Assessing Effectiveness of Research for Load Shedding in Power System

“…There are less evidence to highlight this trade-off.  As per the discussion laid by Lakra [12], there are three types of load shedding schemes i.e.conventional. adaptive, amd computational intelligent schemes.…”

“…Review work on under-voltage schemes was also published by Verayiah [10] and Mozina [11]. Review of load shedding techniques has also been seen in the work carried out Lakra and Kirar [12] where a good and simple description of load shedding schemes can be found. Hence, we carry out further updation of the recent works with respect to different forms of technqiues that has not been discussed or reviewed in the existing system.…”