Control system of variable speed pumped storage hydropower system and method of controlling the same

A method of controlling a variable speed pumped storage hydropower system including a secondary excitation device configured to apply a current to a secondary winding of a generator-motor, a flow rate adjusting valve control unit configured to control an opening of a flow rate adjusting valve that adjusts a flow rate of a pump-turbine directly connected with the generator-motor, and a speed control unit configured to generate a secondary current active power component command value of a secondary excitation device, the method comprising:

• an optimization processing process of generating a generator-motor output command value based on a demanded generator-motor output, and calculating and output a flow rate adjusting valve opening demand value and a first command value from a head value and the generator-motor output command value, the first command value including a slip command value, a rotational speed command value, an angular velocity command value, or a secondary frequency command value, by a control system;
• a speed control process of generating a secondary current active power component command value of the secondary excitation device based on the first command value;
• an output compensation process of calculating a compensation value of the secondary current active power component command value;
• a mechanical output compensation process of calculating at least either a compensation value of the opening of the flow rate adjusting valve or a compensation value of the generator-motor output from a result calculated in the output compensation process;
• and
• an output control process of generating a flow rate adjusting valve opening command value based on the generator-motor output command value, the flow rate adjusting valve opening demand value, the compensation value calculated in the mechanical output compensation process, and the output detection value of the generator-motor, and outputting the flow rate adjusting valve opening command value to the flow rate adjusting valve control unit.