A time-domain method is described for the identification of synchronous-machine equivalent-circuit parameter using on-line measurements obtained while the machine is operating under normal conditions, and is perturbed by a small disturbance. The advantage of this method is that only linear optimization techniques are required to determine the machine parameters and, therefore, convergence is guaranteed. The method requires no disruption of machine service and the identified parameters relate to normal operating conditions. >

Synchronous machine parameter identification: a time domain approach

The authors present a decentralized model reference adaptive control (DMRAC) scheme for the design of power system stabilizers (PSS) and a means for coordinating the generating unit excitation and governor control loops. In the excitation and governor control loops. In the proposed scheme, the state variables of the generating unit (GU) are to track those of an explicitly specified reference system which is designed to have desirable performance characteristics. The adaptive control law for coordinating the exciter-governor stabilizer signals is derived from a Lyapunov energy function, and thus assures system stability. Decentralized regulation and tracking tests on simulated one-machine infinite bus system show significant improvement in system performance. >

Design of a model reference adaptive stabilizer for the exciter and governor loops of power generators

This paper sets forth the experimental procedure for obtaining the parameter set of a synchronous machine model with saturation and arbitrary linear network representation for the rotor. The method utilizes a combination of magnetization curves and standstill frequency-response tests. A novel test procedure is proposed for obtaining the turns ratio. The rotor's transfer function and stator leakage inductance are extracted from the frequency response using genetic algorithms.

Experimental characterization procedure for a synchronous machine model with saturation and arbitrary rotor network representation

This paper describes the application of multi-variable control design methods to the problem of designing co-ordinated stabilizers in a multi-machine environment. Linear state space methods are used to design co-ordinating stabilizing inputs for the exciter and governor loops, based on a number of local outputs. The dynamics of the multi-machine power system are taken into account by determining a dynamic equivalent model of the power system as seen from the transformer bus of the design generator. This is accomplished using identification techniques as described in a previous paper[2]. The generator equations are linearized and combined with this dynamic equivalent of the remainder of the power system, resulting in a reduced order representation of the combined system. Linear optimal control methods are then used to determine the co-ordinated controller. The effects of nonlinearities are taken into account by experimenting with different cost function weightings. The method is demonstrated by applying it to a generating station in an example 63 bus power system with a total of 59 generators represented.

Co-Ordinated Governor/Exciter Stabilizer Design in Multi-Machine Power Systems

Dynamic reduction of large-scale AC/DC power systems via retaining the trunk network

This paper discribes the use of identification methods for the determination of dynamic equivalent models of portions of a power system. The resulting models are linear models for use in stabilizer design and dynamic stability studies. Data for the models are obtained from a transient stability program where small perturbations of the complex voltage on a bus are made, and the resulting complex currents are measured. Using the above data and linear system identification techniques, linear models are obtained relating the complex current to the complex voltage on the bus. The power system as seen from the bus may then be replaced by the model. An example system of 59 machines and 63 buses is used to demonstrate the method[l].

J. D. Aplevich

Papers

Co-Ordinated Governor/Exciter Stabilizer Design in Multi-Machine Power Systems

Dynamic Equivalent Power System Models