Transient Response of an Incinerator Plant by Considering Boiler Model With Dynamic Steam Variation

This paper investigates the effect of boiler steam system on transient response of turbine generators for an incinerator plant. By performing the test of cogeneration units, the mathematical models of turbine generator, governor, and boiler have been identified, which are used in the computer simulation to solve the steam pressure and system frequency of the cogeneration system for islanding operation after tie line tripping. Due to the variation of trash heat value, the power output of the cogeneration unit is stochastically varied with the steam generation for normal operation, which will cause the dynamic change of tie line power flows. For the severe fault contingency of external power systems, the cogeneration system will be isolated by tie line tripping, and the system frequency response is then determined by including the boiler effect to represent the dynamic steam generation. Because of more sluggish response of the boiler system caused by unstable trash heat value, the transient response of the incinerator governor system is inferior to that of conventional industrial cogeneration systems. To maintain the system stability for successful islanding operation of the incinerator plant, the amount of load shedding after tie line tripping has to be properly determined based on the transient stability analysis by considering the response of boiler system.