In this dissertation a new model for the synchronous machine is presented. This model, based on non-standard test data, allows for the appropriate modelling of the frequency dependent behaviour of the damper windings. The non-standard test data consist of frequency responses, either measured or calculated. The form of these responses will automatically determine the order of the resulting model. Saturation effects in the synchronous machine are also modelled with this new method. The model was successfully tested in both an electromagnetic transients program (EMTP) and in a stability program. It was found that when frequency response measurements are used directly, the model is more accurate than when using the standard data from the manufacturer or data estimated to match approximately the frequency response measurements. It was also ascertained that this model could be used to speed up the solution in a stability program, both by allowing the user to match the order of the model to the required accuracy depending on the event and integration step, and by modifying the input frequency response data to minimize the discretization error made when using large integration steps. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate

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by Lam Chun-wing. / Chinese title: / Bibliography: leaves 131-135 / Thesis (M.Phil.)--Chinese University of Hong Kong, 1983

A relatively new development in the electric machines field has been the written-pole technology, of which the latest product is the large single-phase electric motor, the single phase Written-Pole Motor (WPM). The WPM is a synchronous, permanent-magnet single-phase motor having a weak rotor cage for start-up which in addition exhibits significant hysteresis effects at speeds below or above true synchronism. The electrical configuration of the WPM places it in the capacitor-start capacitor-run category of single-phase motors, due to the large size and need for an approximation of a round rather than elliptic rotating magnetic field. This thesis presents the results of the research conducted by the author in the Motor Systems Resource Facility (MSRF) of the Electrical and Computer Engineering Department at Oregon State University. The thesis is structured into two main parts: Testing and Modeling. The tests conducted on the WPM were trying to independently verify manufacturer's claims with regards to efficiency, power factor, robustness, power-outage ride-through and furthermore to study the behaviour of the machine during voltage sags, overvoltages and undervoltages. Tests were conducting in order to develop a mathematical model from which the performance of the machine can be predicted. The modeling efforts were concentrated in the development of a comprehensive model which would include all three major aspects of the WPM, and the performance of the resulting model was compared with the sampled data. / Graduation date: 1999

The Brush less Doubly-Fed Machine (BDFM) has the potential to be a more cost effective replacement for conventional induction or synchronous machine drives. The BDFM has two stator windings: a power winding and a control winding. An electronic power converter of variable voltage and frequency is connected to the control winding and allows the speed of the machine to be adjusted synchronously. The power winding, by design, carries the majority of the current needed for operation, the control winding only a fraction of the current, thus enabling the converter rating to be as low as 25% of the rating of the machine depending on the speed range of operation. To date, only one specific stator pole-pair combination has been investigated, namely the 3/1 combination, where 3 and 1 refer to the power winding pole-pairs and the control winding pole-pair, respectively. Since the speed of the machine is dependent on the sum of the pole-pairs of the stator windings, a general pole numbered model is needed to evaluate the performance of such general machines with other pole-pair number machines. The BDFM describing system equations are transformed to the two axis (dq) rotor reference frame using a power invariant transformation. The analysis shows an additional term involving the common bar impedance which was not present in earlier analyses. The dynamic model is simplified to yield a steady state synchronous model. The synchronous frequency of analysis is investigated which results in two equivalent steady state models. The models developed can easily handle excitation of any frequency or sequence on the control winding without the use of an auxiliary model as used in previous analyses. The voltage forced model predictions match data taken for a 5 hp BDFM laboratory prototype, establishing the validity of the analysis. The model is used in illustrating the torque producing capabilities and unity power factor operation of the machine under a variety of inputs. Using the model, predictions are made on a different pole-pair combination machine (4/2 BDFM) for use as a 60 hp pump drive as an alternative to a 3/1 BDFM for the same application. / Graduation date: 1995