Descripció del projecte
This project will develop and apply a new analytical, multi-objective, dynamic, optimisation methodology to optimise electric motors for hydraulic applications.
In the current century, the global warming and resources scarcity have become an important issue to be attended. In terms of preventing global warming and conserving natural resources, the use of energy efficient tecnologies is of paramount importance. Among the most suited electric motor types taking into account the efficiency are the rare-earth-based PMSMs (permanent magnet synchronous motors) highlight due to their superior characteristics, including specific power, speed range capability or efficiency, although other topologies may be analyzed, such as rare earth free PMSM, synchronous reluctance motors,among others.
The project will seek to identify effective and feasible strategies to enhance efficiency, performance and range of the electric motors to be developed. The project also aims to develop improved modelling techniques and methodologies for motor mapping. The research activity will ultimately deliver improved, exploitable, fundamental knowledge of motor control and optimisation for performance and range of electric motors.
Due to high dynamic demand of hydraulic applications, very compact and stiff components are needed to fulfil the requirements of the load. The highest power density and a very low losses are therefore needed in order to develop an attractive solution and to satisfy the requirements. An investigation on the state of art of components has to be done focusing on the improvements to be developed fot the industry. The investigation is interested to improve these aspects in order to improve the competitiveness of the manufacturer
· efficiency
· power density
· speed range
· reliability
· cost
Typically, the improvements are focuse three different approaches:
· materials
· structure, dimensions or topology
· control
This work is focused to minimise the ratio power/ volume or mass/ torque of the motor by considering the real limits of temperature during the operating cycle. The sizing strategy is composed of two steps.
The first step is the sizing optimization of the motor with the operating point of the cycle. In this step we allow high level of flux density and the level of current density in the conductors exceeds the usual level for the continuous operating of the machine. These two parameters can reduce significantly the volume of the machine.
The second step checks the temperatures in the machine by simulating the entire cycle. So suitable models for optimization tools are carried out and are a compromise between the time computing and the required accuracy. Consequently, a magnetic model taking account of the cross saturation in the machine by using the nodal network method has been carried out ; efficient iron losses model in the flux weakening operation has been carried out and thermal model using too the nodal network method has been carried out. The thermal model is the main point for the sizing strategy so, a particular attention is needed.
