Fault-Tolerant SRM Drive with a Diagnosis Method Based on the Entropy Feature Approach

Abstract

The power electronic converter design is essential for the operation of the switched reluctance motor (SRM). Thus, a fault-tolerant power converter is fundamental to ensure high reliability and extend the drive operation. To achieve fault tolerance, fault detection and diagnosis methods are critical in order to identify, as soon as possible, the failure mode of the drive. To provide such capability, it is proposed in this paper a new fault-tolerant power converter scheme combined with a fault detection method regarding the most common power semiconductors failures in SRM drives. The fast and reliable proposed diagnosis method is based on the entropy theory. Based on this theory, normalized indexes (diagnostic variables) are created, which are independent from the load and speed of the motor. Through this method, it is possible to identify the faulty leg, as well as the type of power semiconductor fault. To test and evaluate the proposed solution several laboratory experiments were carried out using a 2 kW four-phase 8 / 6 SRM.

Diagnostically Oriented Experiments and Modelling of Switched Reluctance Motor Dynamic Eccentricity

“…The induced voltage in the inductive element modelling the k -th winding phase is given by the equation [ 16 ]: …”

“…In [ 6 ], the authors simulate the SRM motor performance at time-varying conditions using Wigner–Ville distribution. In [ 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ], the authors present different approaches for motor modelling either 2D or 3D with different physical phenomena. In [ 17 ], there is a fine introduction to SRM modeling with comparison to test bench analysis but without any diagnostic components.…”

A Review of the Power Converter Interfaces for Switched Reluctance Machines

“…The proposed solution, presented in [91], uses the same principle of [90] with some improvements regarding fault-tolerant operation. This solution also depends on using healthy legs to control two phases not in sequence, such as phases 'A' and 'C' or phases 'B' and 'D,' in a four-phase SRM, but it uses several changeover solid-state relays (SSRs) to connect the faulty legs to other healthy phase in order to replace and isolate the faulty devices.…”

“…However, there are several faults in which that capability is not achieved. For example, in case of an open-circuit failure of outer power devices (see Figure 14a) [91] using a healthy leg to control two phases not in sequence. This solution requires several solid-state relays (SSRs) to connect the faulty legs to other healthy phase in order to replace and isolate the faulty power semiconductors.…”

“…Figure 26.Fault-tolerant topology proposed by[91] using a healthy leg to control two phases not in sequence. This solution requires several solid-state relays (SSRs) to connect the faulty legs to other healthy phase in order to replace and isolate the faulty power semiconductors.…”