Projects: Projects for Investigator
Reference Number EP/C007395/1
Status Completed
Energy Categories Energy Efficiency(Other) 50%;
Other Power and Storage Technologies(Electricity transmission and distribution) 25%;
Energy Efficiency(Industry) 25%;
Research Types Basic and strategic applied research 100%
Science and Technology Fields ENGINEERING AND TECHNOLOGY (Electrical and Electronic Engineering) 100%
UKERC Cross Cutting Characterisation Not Cross-cutting 100%
Principal Investigator Professor E Levi
No email address given
Liverpool John Moores University
Award Type Standard
Funding Source EPSRC
Start Date 01 December 2005
End Date 30 November 2007
Duration 24 months
Total Grant Value £209,635
Industrial Sectors Energy
Region North West
Programme Materials, Mechanical and Medical Eng
Investigators Principal Investigator Professor E Levi , Engineering, Liverpool John Moores University (100.000%)
  Industrial Collaborator Project Contact , Liverpool John Moores University (0.000%)
Project Contact , Moog Italiana S.r.l., Italy (0.000%)
Project Contact , Semikron Ltd (0.000%)
Project Contact , Verteco Ltd (0.000%)
Web Site
Abstract Numerous industrial applications require two or more variable-speed electric drives, which have to be controlled independently. The existing solution for such applications consists of a set of three-phase motors, which are all supplied from individual three-phase voltage-source inverters and the inverters are customarily paralleled to the common dc link. A fundamentally different concept for a multi-drive system, based on utilisation of multi-phase machines (with a phase number greater than three), is currently in the final year of investigation in an EPSRC project. The concept requires an appropriate series connection of stator windings of a certain number of multi-phase machines and the supply comes from a single multi-phase inverter. Vector control principles are applied to achieve decoupling of the dynamics of different machines in the group. The concept has already been demonstrated to be feasible both theoretically and experimentally and its main benefit, when compared to the standard solution with three-phase machines, is a saving in the required number of inverter legs.This proposal is conceived as a logical successor of the current EPSRC project. It intends to explore the possibility of achieving a saving in the number of required inverter legs using a set of motors paralleled to a multi-phase inverter. This eliminates a drawback of the series connection related to the need to have both beginnings and endings of each stator phase brought out to the terminal box. The project is organised along two research tracks, depending on the number of phases of the motors used. The first track investigates use of paralleled multi-phase machines, supplied from a multi-phase inverter, while the second track looks at utilisation of paralleled three-phase machines, supplied from a multi-leg inverter (with a common inverter leg for the third phase of all machines). Both configurations enable saving of the same number of inverter legs for the given number of machines. It should be noted that both multi-drive configurations are believed to offer a potential for a substantial saving in the required installed inverter power in winder applications.The intention is to develop at first theoretically these two novel concepts and to examine next the characteristics by simulation. Vector control principles will be used and it will be necessary to develop appropriate methods for multi-phase (multi-leg) inverter PWM control in order to apply current control in the rotating reference frame (the emphasis will be on space vector modulation). Experimental part of the project will aim at proving the existence of decoupled dynamic control in these two configurations and will rely heavily on the experimental rig designed and commissioned as a part of the work on the current project. The final part of the research will conduct a comparative analysis of the advantages and shortcoming of the two proposed paralleled multi-drive systems using the standard three-phase multi-drive system, with inverters paralleled to the dc link, as a benchmark. The comparison will include the series-connected multi-phase multi-drive systems as well, thus enabling establishment of guidelines for future use of multi-drive systems
Publications (none)
Final Report (none)
Added to Database 23/03/12