Simulation of Turbine Governing in Time Domain

In this work there have been developed rational approximations for the elastic pressure/flow transfer function in a pipe. The approximation method is called Limited Zero and Pole Method, and it approximates the function with a selected number of its own zeros and poles. The method was carried out by Li [3] for a system without friction. The approximation has been successfully extended by including a stationary friction term. Originally, the pressure/flow transfer function is a transcendent.’ function, but becomes algebraic and linear through the approximation, This rakes it possible to transfer the function from the frequency domain to the time domain, to use modern automatic control theory for linear systems. A state space formulation are established and the pressure and the flow are simulated in time domain. The simulations are compared with results computed by the well known Characteristics Method, described by Streeter & Wylie [1]. The results shows very good agreement.