Distributed current control for multi-three phase synchronous machines in fault conditions

Among challenges and requirements of on-going electrification process and future transportation systems there is demand for arrangements with both increased fault tolerance and reliability. Next aerospace, power-train and automotive systems exploiting new technologies are delving for new features and functionalities. Multi-three phase arrangements are one of these novel approaches where future implementation of aforementioned applications will benefit from. This paper presents and analyses distributed current control design for asymmetrical split-phase schemes composed by symmetrical three phase sections with even number of phases. The proposed design within the dq0 reference frame in nominal, open and short circuit condition of one three-phase system is compared with the vector space decomposition technique and further validated by mean of Matlab/Simulink® simulations.

I. Introduction

Electrification of future transportation systems is demanding for more reliability and fault tolerance than current fossil fuel solutions are able to guarantee. Nowadays, the multi-three phase machine concept is gaining popularity [1], [2] thanks to the repetition of a very well-known system: a two level voltage source converter controlling a three phase machine with a three phase set of windings (a, b, c) in Fig. 1. The repetition of this unit block (or module, or segment) establishes the multi-three phase machine concept in Fig. 2. The DC/AC converters are connected in parallel rather than in series. Indeed if wired in series, a fault in one converter would affect all the others.