Power System Frequency Dynamic Simulation Analysis and Tool Development of PSS/E

The continuous increase of the penetration of renewable energy sources makes system frequency dynamic behaviors change greatly under disturbance accidents. Obtaining system frequency response accurately is conductive to frequency dynamic behavior analysis and stability control strategies analysis. In this paper, PSS/E function extension is realized by using Python program to establish the auxiliary model and simulate boiler dynamic process and call the Application Program Interfaces (APIs). Adopting the given model structure and modifying the constant parameter makes PSS/E could consider the influences of frequency deviations on the output of boiler and auxiliaries. PSS/E function extension solves the disadvantage that PSS/E cannot handle the scenario with large frequency deviations in electromechanical transient simulation function. IEEE 39-buses system is used to illustrate the effects of boiler thermal state and the output of auxiliary on system frequency response characteristics and the validity of PSS/E extension modeling is verified by this typical example system.

I. Introduction

The increasing penetration of renewable energy leads to the system inertia decreasing, which brings a potential threat to power system frequency security and stability[1], [2]. The active power deficits will result in a wider range of frequency deviations. Several actual power grid accidents analyses show that the dynamic response trajectory deviates from the numerical simulation results under severe disturbance accidents. The adaptability of the traditional frequency security and stability analysis model is facing challenges [3], [4]. Therefore, obtaining a system frequency response curve rapidly and accurately is conductive to frequency security and stability state analysis, frequency control strategies analysis, and design.