New design of composite controllers for synchronous machines via separation of timescales

The paper presents a new approach to the design of composite controllers for synchronous machines. The slow and fast state feedback controllers, which constitute the composite controller, are designed using the slow and fast subsystems obtained via iterative separation of timescales. Furthermore, stabilisation of the synchronous machine is investigated and it is found that the dynamic response is improved when the iterative approach is used as against the classical quasi-steady-state (QSS) technique. The approach presented does not require a knowledge of the perturbation parameter.