Improvement of Dynamic Reactive Power Characteristics of New-type Condenser by Excitation Parameters

Abstract

The new-type condenser has the capability of dynamic reactive power compensation under subtransient, transient and steady-state, which could effectively solve the problem of insufficient dynamic reactive power reserve under the background of large-scale development of UHVDC transmission. In this paper, the excitation system parameters of the condenser are taken as the research object. First, the basic principle of new-type condenser and the excitation system model are introduced. Then, an effective gain of reactive current is defined as the quantitative index of the dynamic reactive power characteristics of the new-type condenser, and the effect of excitation system parameters on the dynamic reactive power characteristics of new-type condenser is studied by frequency domain trajectory sensitivity analysis. Finally, the simulation model of the condenser grid connected system is built based on PSCAD/EMTDC, the steady-state reactive power output level and transient response characteristics of new-type condenser with different excitation parameters are studied, and the optimization direction of the condenser excitation system parameters is determined. The simulation results show that reducing k A, k p, k D, T m and increasing k I T D, T Z are beneficial to improve the steady-state reactive power output of the condenser. Decreasing k A, k p, k D and increasing k I, T D, T m, T Z are beneficial to improve the transient response characteristics of the condenser.