The survey of the combined heat and compressed air energy storage (CH-CAES) system with dual power levels turbomachinery configuration for wind power peak shaving based spectral analysis

From the wind power spectrum density, wind energy fluctuations include various components with different frequencies and amplitudes. The hybrid energy storage, in this context, is a good choice for mitigating the wind power fluctuations effectively. Combined heat and compressed air energy storage (CH-CAES) system as a new CAES concept, can enlarge the system power/energy level with fixed underground cavern volume. Indeed, the CH-CAES system can be considered as a type of hybrid energy storage technology in which the compressors and electric heater are the two kinds of complementary energy storage elements. In this paper, the feasibility of utilizing the CH-CAES concept into wind power system for a peak shaving purpose is proposed. Based on the low-frequency, high-amplitude and high-frequency, low-amplitude components in wind power fluctuations, the CH-CAES system employs compressors and electrical heater to handle these components, respectively. Moreover, the turbomachinery in CH-CAES possesses a dual power levels configuration. The off-design models of key components are established to explore the CH-CAES system behavior when it is integrated with fluctuating wind power. Meanwhile, the components capacity is determined by using the spectral analysis method. The simulation results show that the CH-CAES system with dual power levels turbomachinery configuration can smooth out the wind power fluctuation effectively.