Method and apparatus for identifying S-characteristic of pump turbine, and control method

A pump turbine control method, applied to a pumped storage power station, the pumped storage power station comprising at least one pump turbine, at least one rotation speed measurement device and at least one flow rate measurement device that are in a one-to-one correspondence with the pump turbine, and a control device, the method comprising:

• identifying, by the control device, whether the pump turbine enters an S-characteristic region using a method for identifying an S-characteristic of a pump turbine to obtain an identification result;
• and
• regulating, by the control device, a speed of the pump turbine according to the identification result and a power generation amount of the pump turbine;
• wherein the method for identifying the S-characteristic of the pump turbine includes:
• collecting a set of state parameters of the pump turbine at a preset time interval through the rotation speed measurement device and the flow rate measurement device, wherein the state parameters comprise a flow rate obtained by the flow rate measurement device and a rotation speed of the pump turbine obtained by the rotation speed measurement device;
• calculating, by the control device, a slope of a relationship curve between the rotation speed and the flow rate of the pump turbine within a current preset time interval;
• and
• determining, by the control device, whether the pump turbine enters the S-characteristic region according to a positivity or negativity and an absolute value of the slope, including:
• determining whether the slope meets at least one of a first condition or a second condition, wherein the first condition is that the slope is positive, the second condition is that the absolute value of the slope is greater than a first preset value, the first preset value being equal to a product of a preset coefficient and a historical slope, the historical slope being a slope of the relationship curve within a previous preset time interval;
• determining that the pump turbine enters the S-characteristic region when the slope meets at least one of the first condition or the second condition;
• and
• determining that the pump turbine does not enter the S-characteristic region when the slope does not meet the first condition and the second condition.