Simulation of the modes of operation of an AFPC system with controllable loads

Abstract:

The use of controllable loads in a system of automatic frequency and power control (AFPC) requires performing additional studies for determination of the parameters of the relevant laws of control, which is caused by technological differences (primarily by the inertial characteristics) from AFPC with regulating generators. For this purpose, a comparative analysis of the quality of control was performed by using the basic laws of control: proportional, proportional-differential (PD) and proportional-integral-differential (PID).
The present work was carried out by the numerical simulation of AFPC of the Ukrainian Interconnected Power System with an emergency perturbation. The efficiency of the laws of control was determined on the basis of analysis of the traditional parameters of quality of control (the maximum frequency deviation, the duration of the transient process and its nature, the presence of statics).
It has been established that the use of proportional law is not reasonable due to the oscillatory nature of the transient process and exceeding the limiting value of the maximum frequency deviation. The PD-law is the most efficient. When it is applied, AFPC satisfies the requirements of ENTSO-E and exceeds the most efficient configuration of AFPC with regulating generators at all parameters. PID-law is less efficient than PD-law, but it may be advisable to ensure the stability of the system.