The development of electrical machines for converting power between mechanical and electrical forms is central to a low-carbon future. The pace of development in electrical machines is higher now than ever before as we seek to remove weight, remove cost, improve reliability, use only sustainable materials and exploit better manufacturing and material developments. Concerns about mechanical dynamics introduce design constraints on electrical machines. Traditionally, designers make the system mechanically stiff so that the first major resonance frequency lies comfortably above highest rotor spin speed. Avoiding this constraint can reduce cost and mass significantly. The best way to do this is to get the electrical machine itself to produce forces helping to control vibration. In effect, we can make the electrical machine behave like a magnetic bearing also. More concisely, we aim to achieve “vibration control using unbalanced magnetic pull” (VCUMP).
The earliest designs for VCUMP machines had two completely different sets of windings in the machine and/or they used very non-standard power-electronic arrangements to drive the machine. These arrangements are impractical in most contexts because they introduce substantial cost, mass and unreliability in the new electrical/electromagnetic arrangement. This PhD is about engineering VCUMP machines that add virtually zero cost, mass or unreliability in the electrical/electromagnetic arrangement relative to a “standard” electrical machine. By utilising clever connections of coils within the machine stator, we can ensure several desirable attributes: (1) the additional mass of conductors required in the VCUMP machine is minimal (often zero), (2) the machine will act exactly as a “normal” electrical machine if no sideways forces are required on the rotor, (3) that if something goes wrong with the features that either determine what sideways forces should be exerted or that drive the currents to implement those forces, these cannot interfere with the normal operation of the electrical machine and (4) the sideways forces can never cause a problem of their own in the mechanical dynamics. Such VCUMP machines are possible and they have the potential to achieve very widespread deployment in applications including white goods, hand-tools, renewable energy generators, nuclear power generation, electrified aerospace propulsion, laboratory equipment, manufacturing equipment, primary power-train machines and range-extenders in ground-based and water-based transportation and space equipment.
The PhD will benefit from expert supervision from two leading research groups at the University of Nottingham – the power-electronics, machines and control (PEMC) group and the gas turbines transmissions research centre (G2TRC). Both have experience of VCUMP machines. The work will call for understanding of both electrical machines and mechanical dynamics so a first degree in either electrical engineering or mechanical engineering is an essential pre-requisite. Whichever engineering discipline has been studied for the first degree, the candidate will likely have to learn a little of the other but the resource is present to support that learning. The work will involve (i) coupled modelling of the combined electro-mechanical dynamics of the system using tools already developed in MATLAB as well as industry-standard tools such as ANSYS, (ii) experimentation to explore and to prove the efficacy of the methods being investigated, (iii) design developments building on concepts that have been introduced already and conceiving extensions of those to improve practicality.
Interested candidates should consult [email protected] .