Abstract: The time scale is a ruler used to describe the speed characteristics of a control system and can be used to correct the controller parameters. The structure of the control system with time scale correction and its parameter setting and tuning method are introduced in this paper. The implementation of time scale correction and the tuning procedure applied to the main steam pressure control system of a 1 000-MW ultra-supercritical coal-fired power generation unit are presented. The performance of the main steam pressure control system in terms of deep peak regulation and large load variation shows that time scale correction is a simple but effective method for variable parameter control and has the potential to reduce the working load and shorten the time of on-site commissioning.

Key words: time scale, parameter correction, control system, tuning, ultra-supercritical unit