Patent AU-2015381975-B2 (AU)
Title: Method for quantitative evaluation of switched reluctance motor system reliability through three-level Markov model
Inventor: CHEN HAO
IPC: G01R31/34
Filed: 2015-12-28
Granted: 2017-07-27
Abstract: Abstract The invention discloses a method for evaluation of switched reluctance motor system reliability through quantitative analysis of three-level Markov model. Through analysis of the operating condition of switched reluctance motor drive system under first-level faults, second-level faults and third-level faults, 4 valid states and 1 invalid state under first-level faults, 14 valid states and 4 invalid states under second-level faults, and 43 valid states and 14 invalid states under third-level faults are obtained. If initial normal state and final invalid state are also considered, a three-level Markov model will have 62 valid states and 20 invalid states in total. A state transition diagram of the switched reluctance motor drive system under three-level faults is established, a state transition matrix is obtained, a probability matrix P(t) of the system in valid states is attained, the sum of all elements of the probability matrix P(t) in valid states is calculated, and MTTF is obtained from reliability function R(t) through calculation, thereby realizing evaluation of switched reluctance motor system reliability through quantitative analysis of a three-level Markov model. The method has a desirable engineering application value. Drawings Cl A] A c : CS F6 B3 10 CIO F8 All ' l 4 Cl P I C, 12 Ac 1 CI3 A Flo C14 Fli A,5 B5 1 c 1 ' F12 __N\ 4 B6 AC17 CIS O C19 'A F 1 5 A17 11C 21 C21 16 AC 2 2 /C22 A F17 B8 A, c, I '25 B9 1A1C 2 8 27 c A Aglo BJO ,43 0 j *- I/ I C3 A F23 F C32 C31 /1F24 BI 11 33 AF25 I'll- 34 C33 AF26 A3 A812 '- N A C35 C34 I B12 36 C3 427 A 813 1 C37 11F28 B13 1 , 39 C38 _" AC40 \_ C39 F30 /114 /1814 B14 41 C4Q F3 11C42 I C42 915 C4 I A4 44 1-) 11F33 BI 1 5 A 45 C44 C45 /I F3 AC47 C46 C47 F' /1817 "1" /1 C49 C4 /1F37 B16 /115 A 50 C50 5 C52 /1F4 B17 -1 A5 56 C55 AF Claims 1. A method for evaluation of switched reluctance motor system reliability through quantitative analysis of three-level Markov model, wherein it has the following steps: through analyzing the operating condition of switched reluctance motor drive system under first-level faults, second-level faults and third-level faults, 5 first-level Markov states including 4 valid states and 1 invalid state, 18 second-level Markov states including 14 valid states and 4 invalid states, and 57 third-level Markov states including 43 valid states and 14 invalid states are obtained in total; if initial normal state and final invalid state are also considered, a three-level Markov model will have 62 valid states and 20 invalid states in total, a state transition diagram of the switched reluctance motor drive system under three-level faults is established and a valid-state transition matrix A under three-level faults is obtained: Al All A12 A13 state transition matrix A is a square matrix with 62 lines and 62 columns, the lines of state transition matrix A stand for initial valid states, the columns of state transition matrix A stand for next states to be transferred, corresponding transition rates are corresponding elements in state transition matrix A, and the transition rate of a state is the opposite number of the transition probability sum of the transition from this state to all states (including invalid states); in Formula (1), A1, All, A12, A13, A2, A3, A4 are nonzero matrices, 0 stands for zero matrix, and sub-matrix Al is a square matrix with 13 lines and 13 columns: Al= 0 B2 0 (2) in Formula (2), B1, B21, B31, B2, B3 are nonzero matrices, 0 stands for zero matrix, B21 and B31 of the five nonzero matrices have only one nonzero element, the rest elements are all zero elements, and the five sub-matrices are: AlA 0 0 0 0 0 -(BB+ 0 0 0 B1= 0 0 -(l + c2 + l + C4) ll c2 c3l 0 0 -42 0 0 0 0 0 -u2 0 0 0 0 0 -AF3 (3) B2= 0 -"F24 0 0 0 -'F5_(4