KPI scientists develop UFLS Scheme making power grids smarter

In the course of the operation of energy power grids, it is impossible to avoid completely accidents followed by a major frequency drop that is lower than 49 Hz. Such accidents entail heavy financial losses, which affect the national budget of a county and may well cause technological disasters.

Therefore, to reduce the risks of the collapse of a power grid, automatic emergency control devices (AECD) are installed. The AECD reduce electric power consumption by cutting off a certain group of consumers from the electricity supply. This process of selective electricity cuts is called the under-frequency load shedding (UFLS).

The AECD are conventional UFLS relays that have a set point. For instance, there are 3,500 UFLS relays scattered up and down the entire power grid of Ukraine, which can operate in a decentralized or centralized mode through an integrated control center.

To make under-frequency load shedding efficient, it is necessary to build the UFLS Scheme on all the relays. Scientists of the Kiev Polytechnic Institute (KPI) have developed the decentralized UFLS Scheme that enables it to operate smoothly even during cyber attacks.

The UFLS Scheme is the last echelon of protection of a power grid. At what stage a cascade accident will come to a stop is contingent on the efficiency of the above scheme:

- whether it is the total collapse of an electric power pool with the large-scale cut-off of electricity consumers;

- whether it is temporarily controlled balancing of separated regions that would enable the minimization of time required to revitalize the electric power pool.

KPI researchers offer to use the software (with their maintenance) in national power grids, which enables the establishment of the under-frequency load-shedding (UFLS) scheme based on the analysis of emergency modes and synthesis of the UFLS scheme. This approach makes it possible to compute the optimum set point relay, as well as to set up the UFLS scheme that would balance the power grid or its pinpointed part in any accident.

It is expedient, from the viewpoint of KPI researchers, to establish relationships with national power grids, involving technical universities.