Quasi-steady state variable step simulation method applicable to long time scale in power system

Abstract

The invention discloses a quasi-steady state variable step simulation method applicable to a long time scale in a power system, belonging to the field of simulation technology of power systems. The method comprises the steps of firstly establishing a quasi-steady state simulation model of the system, performing load flow calculation on the power system to obtain a steady state value of each variable, and then selecting a numerical integration method according to the state of the system, wherein when the system is in a quick change phase, an improved Euler method of a fixed step is adopted for solving; and when the system is in a slow change phase, an implicit trapezoidal integration method of a variable step is adopted for solving. The method improves the quasi-steady state simulation speed of the power system, also improves the stability of the numerical algorithm, and overcomes the defects of the quasi-steady state simulation method for the long time scale in the power system.

Description

technical field [0001] The invention belongs to the technical field of power system simulation, and in particular relates to a quasi-steady-state variable step-size simulation method suitable for medium and long-term scales in power systems. The solution of the differential equation in the mathematical model is divided into two stages, the fast-changing stage is solved by the improved Euler method with fixed small step size, and the slow-changing stage is solved by the implicit trapezoidal integration method with variable step size. Background technique [0002] Usually, the dynamic process with a fluctuation time of several seconds to tens of seconds is called short-term transient stability, and the full-time domain simulation method is generally used for simulation; the dynamic process with a fluctuation time of tens of seconds to several minutes is called long-term transient Stability, because the full-time domain simulation method uses detailed models for all components,...

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Problems solved by technology

Therefore, the step size of the improved Euler algorithm is greatly limited, and the simulation usually can only use a smaller step size, which limits the simulation speed

[0024] The quasi-steady-state simulation ignores the smaller time constants, and only retains the larger time constants, which speeds up the system simulation speed. However, the quasi-steady-state simulation method usually uses the improved Euler method to solve the differential equations, and the system stability is low, and The improved Euler method limits the simulation step size so that the simulation step size cannot be too large. Therefore, the simulation time for medium and long-term scale simulations of power systems using quasi-steady-state simulations is still relatively long

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