Ore Olubamiwa

Stellenbosch University | SUN · Department of Electrical & Electronic Engineering

In this paper, an investigation is conducted into the causes of strong vibrations in a 12/10 DC excited vernier reluctance machine (DC-VRM) prototype operated as a synchronous condenser. FEA models of the machine are simulated at different operating conditions to determine the vibrational characteristics. Experimental validations at similar conditi...

Research interest on brushless doubly fed induction machines (BDFMs) is increasing, as they offer higher reliability compared to doubly fed induction generators (DFIGs) in wind turbines. At the moment, BDFMs do not have a definitive structure nor design process, as literature is rife with different approaches to designing BDFMs. In this paper, a co...

In this paper, it is proposed that design evaluations of brushless doubly fed machines (BDFMs) be conducted at unity power factor in the synchronous generating mode, for wind turbine applications. In the build up to this idea, differences in power output at asynchronous, synchronous motoring, and synchronous generating modes are highlighted and dis...

The brushless doubly fed induction machine (BDFM) is considered as an alternative to doubly fed induction generators (DFIGs) in wind energy conversion systems. However, BDFMs have a complex machine structure, and their operations are relatively complicated. In this study, the winding function theory is used in the development of a coupled circuit (...

Rotor-tied doubly fed induction generators (DFIGs) boast of higher efficiencies than conventional DFIGs and may be more suitable for rotary transformer designs. This paper maps out a methodology for designing rotor-tied DFIGs. Following this methodology, a 5.5 kW rotor-tied DFIG was designed and finite element analysis (FEA) was performed with rele...

The steady state operation of a rotor-tied doubly fed induction generator (DFIG) is described in this paper in relation to slip, the electrical and mechanical frequencies. The ratio of the stator power to the input mechanical power of a rotor-tied DFIG relative to slip is illustrated. The transformer model based equivalent circuit of rotor-tied DFI...