Method and system for calculating stability margin domain of control parameters of hydraulic turbine regulating system

A system for calculating a stability domain of control parameters of a hydraulic turbine regulating system, comprising:

• a construction module of a high-order state space model, used to construct the high-order state space model of the hydraulic turbine regulating system, wherein the hydraulic turbine regulating system comprises a PID governor, a water diversion module comprising a pressure regulating well, a hydraulic turbine, and a generator module;
• an eigenvalue screening module, used to randomly select a set of the control parameter within a PI stability domain, find a conjugate pole without any zero within a preset distance and closest to an imaginary axis in a zero-pole distribution diagram after converting the high-order state space model as a dominant eigenvalue, and determine an eigenvalue closer to the imaginary axis than the dominant eigenvalue as an interference eigenvalue;
• an associated state variable obtaining module, used to calculate a participation factor of each state quantity in the hydraulic turbine regulating system to the interference eigenvalue, and determine the state variable corresponding to the participation factor exceeding a preset value as an associated state variable of the interference eigenvalue;
• an interference eigenvalue inverse solution module, used to input a target control parameter into the high-order state space model to calculate the eigenvalue, and judge a certain eigenvalue as the interference eigenvalue if a ratio of the participation factor of the associated state variable to the certain eigenvalue is more than 50% of the participation factor of all the state variables to the certain eigenvalue;
• a stability margin judgement module, used to judge whether a real part of the eigenvalue after removing the interference eigenvalue is all less than −m, if yes, the target control parameter meets a stability margin requirement;
• wherein m is the stability margin requirement;
• a target control parameter updating module, used to move the control parameter (0,0) according to a step size, and update the target control parameter by adopting the control parameter obtained after each movement, wherein
• the set of all the control parameters meeting the stability margin requirement forms the parameter stability margin domain;
• the interference eigenvalue inverse solution module comprises:
• an eigenvalue solution module, used to input the target control parameter into the high-order state space model to solve for the eigenvalue of a state matrix;
• a participation factor calculation unit, used to calculate the participation factors of all the state variables to all the eigenvalue using the participation factors;
• an interference feature confirmation unit, used to calculate a ratio
• ϕ
• g
• ,
• k
• /
• ∑
• i
• =
• 1
• n
• ϕ
• i
• ,
• k
• of the participation factor of a current state variable to a current eigenvalue in the participation factor of all the state variable to the current eigenvalue, and consider the current eigenvalue to be the interference eigenvalue if
• ϕ
• g
• ,
• k
• /
• ∑
• i
• =
• 1
• n
• ϕ
• i
• ,
• k
• >
• 0.5
• ;
• wherein
• ⁢
• ϕ
• g
• ,
• k
• is a participation factor of a current g-th state variable to a current k-th eigenvalue;
• n is a total number of the eigenvalue;
• an iterative driving unit, used to update the current eigenvalue to a next eigenvalue, and drive the interference feature confirmation unit to find all the interference eigenvalue.