The invention discloses an isothermal
compressed air energy storage system with primary
frequency modulation capability and an operation method thereof. The
system comprises a high-pressure air storage cavity, an impulse
turbine, a synchronous power generator and at least two working units, wherein the working units are connected in parallel, the top ends of the working units communicate with the high-pressure air storage cavity and the
tail water pipeline of the impulse
turbine, the bottom ends of the working units arecommunicated with the water inlet of the impulse
turbine through a pipeline, the working unit comprises two compression tanks, a top outlet formed by connecting the two compression tanks in parallel serves as the top end of the working unit, two pipelines are arranged at the bottom ends of the two compression tanks, the first pipeline is used for connecting the two compression tanks in parallel and serves as the bottom end of the working unit, the second pipeline is communicated with the two compression tanks, a water pump
system is arranged on the second pipeline, and a
nozzle with an adjustable opening degree is adopted in the impulse turbine. According to the invention, long-
time constant-
power output can be achieved, the purpose of stable overall output power is achieved through phase-shifting superposition of the multiple independent working units, the opening degree adjusting time of the
nozzle is short, and throttling loss is small.