FAULT-TOLERANT CONTROL METHOD FOR POSITION SENSOR OF SWITCHED RELUCTANCE MOTOR

20170324358 · 2017-11-09

Inventors

Cpc classification

International classification

Abstract

A fault-tolerant control method for a position sensor of a switched reluctance motor, if the position sensor of the switched reluctance motor runs without a fault, detecting, in real time, four equal-interval or equal-angle continuous edge pulses of an output signal of the position sensor, the fourth edge pulse being the current edge pulse, and detecting time intervals (T1, T2, T3) between each two adjacent edge pulses sequentially, thereby calculating a time interval (T4) between the current edge pulse and a next edge pulse following the current edge pulse. If the position sensor of the switched reluctance motor fails, and the next edge pulse following the current edge pulse is lost, reconstructing the next edge pulse after the interval time (T4) of the current edge pulse of the output signal of the position sensor. The method can be used, when one or more position sensors of a rotatory and linear switched reluctance motor having various phases and various topology structures fail, to reconstruct an edge pulse after lost.

Claims

1. A fault-tolerant control method for position sensor of switched reluctance motor, comprising: when the position sensors in a switched reluctance motor operate without fault, four consecutive equal-space or equal-angle edge pulses in the output signals of the position sensors are detected in real time, wherein, the fourth edge pulse is the current edge pulse, and, in a chronological order, the third edge pulse is earlier than the fourth edge pulse, the second edge pulse is earlier than the third edge pulse, and the first edge pulse is earlier than the second edge pulse, the time interval between the first edge pulse and the second edge pulse is T.sub.1, the time interval between the second edge pulse and the third edge pulse is T.sub.2, and the time interval between the third edge pulse and the fourth edge pulse is T.sub.3, the time interval T.sub.4 between the next edge pulse right after the current edge pulse and the current edge pulse is calculated according to the following formula: $\begin{matrix} T_{4} = \frac{- B + \sqrt{B^{2} - 4 .Math. .Math. AC}}{2 .Math. .Math. A} & (1) \\ A = \frac{T_{1} (T_{1} + T_{2}) .Math. {(T_{2} - T_{3})}^{2}}{T_{3} (T_{2} + T_{3}) .Math. (T_{1} - T_{2})} & (2) \\ B = \frac{T_{1} (T_{1} + T_{2}) .Math. {(T_{2} - T_{3})}^{2} + {T_{2} (T_{2} + T_{3})}^{2} .Math. (T_{1} - T_{2})}{(T_{2} + T_{3}) .Math. (T_{1} - T_{2})} & (3) \\ C = - T_{2} .Math. T_{3} (T_{2} + T_{3}); & (4) \end{matrix}$ if a position sensor of the switched reluctance motor fails and the next edge pulse right after the current edge pulse is lost, the next edge pulse is reconstructed at the time interval T.sub.4 after the time of the current edge pulse; thus, fault-tolerant operation of the position sensors in the switched reluctance motor is realized.

Description

DESCRIPTION OF THE DRAWINGS

[0008] FIG. 1 is an installation diagram of position sensors in a rotary switched reluctance motor in a three-phase 12/8 structure;

[0009] FIG. 2 is a schematic diagram of detection of edge pulses in the output signals and signal reconstruction of position sensors in the rotary switched reluctance motor in a three-phase 12/8 structure;

[0010] FIG. 3 is an installation diagram of position sensors in a rotary switched reluctance motor in a four-phase 8/6 structure;

[0011] FIG. 4 is a schematic diagram of detection of edge pulses in the output signals and signal reconstruction of position sensors in the rotary switched reluctance motor in a four-phase 8/6 structure;

[0012] FIG. 5 is an installation diagram of position sensors in a linear switched reluctance motor in a three-phase 6/4 structure;

[0013] FIG. 6 is a schematic diagram of detection of edge pulses in the output signals and signal reconstruction of position sensors in the linear switched reluctance motor in a three-phase 6/4 structure.

DETAILED DESCRIPTION

[0014] Hereunder the examples of the present disclosure will be further described with reference to the accompanying drawings:

Example 1

[0015] As shown in the installation diagram in FIG. 1, three position sensors P, Q, R are installed symmetrically in a rotary switched reluctance motor in a three-phase 12/8 structure, and the angular interval α is 60°. When the position sensors in the switched reluctance motor operate without fault, as shown in FIG. 2, four consecutive equal-angle edge pulses Q, P, R, Q in the output signals of the position sensors are detected in real time, wherein, the fourth edge pulse Q counted from the left is the current edge pulse, and, in a chronological order, the third edge pulse R is earlier than the fourth edge pulse Q, the second edge pulse P is earlier than the third edge pulse R, and the first edge pulse Q is earlier than the second edge pulse P, the time interval between the first edge pulse Q and the second edge pulse P is T.sub.1, the time interval between the second edge pulse P and the third edge pulse R is T.sub.2, and the time interval between the third edge pulse R and the fourth edge pulse Q is T.sub.3, the time interval T.sub.4 between the next edge pulse P right after the current edge pulse Q and the current edge pulse Q is calculated according to the following formulae:

[00002] $\begin{matrix} T_{4} = \frac{- B + \sqrt{B^{2} - 4 .Math. .Math. AC}}{2 .Math. .Math. A} & (1) \\ A = \frac{T_{1} (T_{1} + T_{2}) .Math. {(T_{2} - T_{3})}^{2}}{T_{3} (T_{2} + T_{3}) .Math. (T_{1} - T_{2})} & (2) \\ B = \frac{T_{1} (T_{1} + T_{2}) .Math. {(T_{2} - T_{3})}^{2} + {T_{2} (T_{2} + T_{3})}^{2} .Math. (T_{1} - T_{2})}{(T_{2} + T_{3}) .Math. (T_{1} - T_{2})} & (3) \\ C = - T_{2} .Math. T_{3} (T_{2} + T_{3}); & (4) \end{matrix}$

[0016] if a position sensor in the switched reluctance motor fails and the next edge pulse P right after the current edge pulse Q is lost, the next edge pulse P is reconstructed at the time interval T.sub.4 after the time of the current edge pulse Q; thus, fault-tolerant operation of the position sensors in the rotary switched reluctance motor is realized.

Example 2

[0017] As shown in FIG. 3, two position sensors P and Q are installed symmetrically in a rotary switched reluctance motor in a four-phase 8/6 structure, and the angular interval β is 75°. When the position sensors in the switched reluctance motor operate without fault, as shown in FIG. 4, four consecutive equal-angle edge pulses P, Q, P, Q in the output signals of the position sensors are detected in real time, wherein, the fourth edge pulse Q counted from the left is the current edge pulse, and, in a chronological order, the third edge pulse P is earlier than the fourth edge pulse Q, the second edge pulse Q is earlier than the third edge pulse P, and the first edge pulse P is earlier than the second edge pulse Q, the time interval between the first edge pulse P and the second edge pulse Q is T.sub.1, the time interval between the second edge pulse Q and the third edge pulse P is T.sub.2, and the time interval between the third edge pulse P and the fourth edge pulse Q is T.sub.3, and the time interval T.sub.4 between the next edge pulse P right after the current edge pulse Q and the current edge pulse Q is calculated according to the following formulae:

[00003] $\begin{matrix} T_{4} = \frac{- B + \sqrt{B^{2} - 4 .Math. .Math. AC}}{2 .Math. .Math. A} & (1) \\ A = \frac{T_{1} (T_{1} + T_{2}) .Math. {(T_{2} - T_{3})}^{2}}{T_{3} (T_{2} + T_{3}) .Math. (T_{1} - T_{2})} & (2) \\ B = \frac{T_{1} (T_{1} + T_{2}) .Math. {(T_{2} - T_{3})}^{2} + {T_{2} (T_{2} + T_{3})}^{2} .Math. (T_{1} - T_{2})}{(T_{2} + T_{3}) .Math. (T_{1} - T_{2})} & (3) \\ C = - T_{2} .Math. T_{3} (T_{2} + T_{3}); & (4) \end{matrix}$

[0018] if a position sensor in the switched reluctance motor fails and the next edge pulse P right after the current edge pulse Q is lost, the next edge pulse P is reconstructed at the time interval T.sub.4 after the time of the current edge pulse Q; thus, fault-tolerant operation of the position sensors in the rotary switched reluctance motor is realized.

Example 3

[0019] As shown in the schematic installation diagram of FIG. 5, three position sensors P, Q, R are installed symmetrically in a linear switched reluctance motor in a three-phase 6/4 structure, the interval distance x is 30 mm. When the position sensors in the switched reluctance motor operate without fault, as shown in FIG. 6, four consecutive equal-interval edge pulses Q, P, R, Q in the output signals of the position sensors are detected in real time, wherein, the fourth edge pulse Q counted from the left is the current edge pulse, and, in a chronological order, the third edge pulse R is earlier than the fourth edge pulse Q, the second edge pulse P is earlier than the third edge pulse R, and the first edge pulse Q is earlier than the second edge pulse P, the time interval between the first edge pulse Q and the second edge pulse P is T.sub.1, the time interval between the second edge pulse P and the third edge pulse R is T.sub.2, and the time interval between the third edge pulse R and the fourth edge pulse Q is T.sub.3, the time interval T.sub.4 between the next edge pulse P right after the current edge pulse Q and the current edge pulse Q is calculated according to the following formulae:

[00004] $\begin{matrix} T_{4} = \frac{- B + \sqrt{B^{2} - 4 .Math. .Math. AC}}{2 .Math. .Math. A} & (1) \\ A = \frac{T_{1} (T_{1} + T_{2}) .Math. {(T_{2} - T_{3})}^{2}}{T_{3} (T_{2} + T_{3}) .Math. (T_{1} - T_{2})} & (2) \\ B = \frac{T_{1} (T_{1} + T_{2}) .Math. {(T_{2} - T_{3})}^{2} + {T_{2} (T_{2} + T_{3})}^{2} .Math. (T_{1} - T_{2})}{(T_{2} + T_{3}) .Math. (T_{1} - T_{2})} & (3) \\ C = - T_{2} .Math. T_{3} (T_{2} + T_{3}); & (4) \end{matrix}$

[0020] if a position sensor in the switched reluctance motor fails and the next edge pulse P right after the current edge pulse Q is lost, the next edge pulse P is reconstructed at the time interval T.sub.4 after the time of the current edge pulse Q; thus, fault-tolerant operation of the position sensors in the linear switched reluctance motor is realized.

[0021] The method provided in the present disclosure is applicable to fault-tolerant control of single position sensor or multiple position sensors in switched reluctance motors with three position sensors in a three-phase 6/4 structure or three-phase 24/16 structure, switched reluctance motors with four position sensors in a four-phase 8/6 structure or four-phase 16/12 structure, switched reluctance motors with two position sensors in a four-phase 8/6 structure or four-phase 16/12 structure, and rotary or linear switched reluctance motors, etc.

FAULT-TOLERANT CONTROL METHOD FOR POSITION SENSOR OF SWITCHED RELUCTANCE MOTOR

Inventors

Cpc classification

Classification Explorer

H02P25/0925

ELECTRICITY

Classification Explorer

H02P6/16

ELECTRICITY

International classification

Classification Explorer

H02P6/16

ELECTRICITY

Abstract

Claims

Description