Novel integrative options for passive filter inductor in high speed AC drives

Abstract

--This paper presents novel integration options for passive inductor which include: motor-shaped rotational and motor-shaped rotor-less inductor for high speed motor drive system. The novel options have been designed and their performance is compared with the conventional EE core inductor using finite element analysis. It is observed that there is a significant reduction in total losses at fundamental frequency along with substantial reduction in the AC copper loss at 10, 15 and 20 kHz switching frequencies, when the proposed integrated options are utilized. For the motor-shaped rotational inductor, the total losses at fundamental frequency and AC copper loss at different switching frequencies are reduced by 26.1% and 73.8% (at different switching frequencies) respectively. There is a reduction in overall volume by 3.6%, but this comes with 11.7% increase in weight. For the motor-shaped rotor-less inductor, the total losses at fundamental frequency and AC copper loss at different switching frequencies are reduced by 10.4% and 73.8% (at different switching frequencies) respectively. There is a reduction in overall volume by 3.6% but this comes with 6.1% increase in weight. The proposed designs can share the cooling system of the motor thus, eliminating the requirement of separate cooling system.

Design optimization of integrated rotational inductor for high-speed AC drive applications

“…Novel integrated options for passive filter inductor which includes: motor-shaped rotational (RT) and rotor-less inductor for high speed AC drives is presented in [4]. Both RT and rotor-less inductor designs are integrated axially, on the same shaft, inside the motor housing and as a result singular shared cooling system can be utilized.…”

“…However, if the rotor is removed [4], it can be a suitable solution for high power line inductors, isolation and power transformers where supply frequency is fixed and cooling requirement is high. These can then be integrated within the motor or generator housing to share the existing cooling system.…”

“…The objective of this paper is to understand the effect of design degrees of freedom on the motor-shaped rotational inductors, proposed in [4], and optimize them for high speed AC drives applications with an aim to reduce losses at both fundamental and switching frequency. Different slot-pole combinations and winding arrangements are considered and compared with a benchmark EE core inductor.…”

“…The rotational inductors were optimized and compare with conventional EE core inductor in terms of total losses, weight and AC copper loss. EE core inductor is first designed [11] and then converted into motor-shaped rotational inductors [4]. For the purpose of …”

“…This leads to a separate sub-system which in turn results in a lossy and bulky overall system. In order to overcome these drawbacks the integration of passive components need to be introduced both from functional and physical point of view [1][2][3][4][5].…”