Primary frequency control scheme for a fixed-speed dish-Stirling solar-thermal power plant

The ability of an induction generator-based dish-Stirling (DS) solar–thermal power plant in providing primary frequency control is examined. A dynamic model of the power plant is developed, in which the receiver/absorber temperature of the Stirling engine is allowed to vary. Primary frequency control is achieved through the adaptive regulation of the receiver temperature set-point and the droop setting of the output power–temperature characteristics of the DS system. However, the penetration level of the solar–thermal generation into the grid system has to be constrained to avoid the onset of instability due to the nonminimum phase characteristics of the DS system. The transient droop compensation technique is then proposed to alleviate the instability issue and results in an increase in the allowable DS penetration level.