Fault management system for a switched reluctance motor
First Claim
1. A fault management system for detecting faults in a multiphase switched reluctance motor employing unidirectional current excitation from a DC source, each phase of said motor comprising two stator poles and a phase winding having two motor leads for connecting the phase winding in series with at least one respective semiconductor switch, said system further isolating any detected faults so that the faulted motor phases are deactivated and motor operation is continued through the remaining phases, said system comprising:
- a plurality of phase control circuits, said phase control circuits each comprising a respective AND gate coupled to a separate respective semiconductor switch, each AND gate generating a low logic level output signal when a fault is detected in the corresponding motor phase, whereby each motor phase exhibiting a fault is deactivated;
a plurality of current sensor means, each respective one of said current sensor means coupled to a separate respective semiconductor switch to sense the instantaneous current in the respective motor phase winding, the output of each of said current sensor means, respectively, coupled to an input of the AND gate of the corresponding phase control circuit, each respective one of said current sensor means generating a low logic level output signal to the AND gate of the corresponding phase control circuit whenever the respective instantaneous phase current exceeds a regulated current limit; and
a plurality of current differential sensor means, each respective one of said current differential sensor means coupled to a separate respective motor phase winding for detecting any difference in current flow between the two leads of each respective phase winding of the corresponding phase, the output of each of said current differential sensor means, respectively, coupled to an input of the AND gate of the corresponding phase control circuit, each respective one of said current differential sensor means generating a low logic level signal output to the AND gate of the corresponding phase control circuit when any difference in current flow between the two leads of each respective phase winding of the corresponding phase is detected.
1 Assignment
0 Petitions
Accused Products
Abstract
A fault management system for a switched reluctance motor detects faults through phase current differential sensing and phase flux differential sensing and isolates any fault by deactivating any faulted phase. Motor operation continues through the remaining phases. A speed control circuit maintains the normal operating speed of the motor, despite the deactivation of one or more phases. Starting the motor when stopped in a "dead zone" created by a faulted phase is accomplished by using the intact phases to generate negative torque to move the rotor out of the dead zone.
122 Citations
36 Claims
-
1. A fault management system for detecting faults in a multiphase switched reluctance motor employing unidirectional current excitation from a DC source, each phase of said motor comprising two stator poles and a phase winding having two motor leads for connecting the phase winding in series with at least one respective semiconductor switch, said system further isolating any detected faults so that the faulted motor phases are deactivated and motor operation is continued through the remaining phases, said system comprising:
-
a plurality of phase control circuits, said phase control circuits each comprising a respective AND gate coupled to a separate respective semiconductor switch, each AND gate generating a low logic level output signal when a fault is detected in the corresponding motor phase, whereby each motor phase exhibiting a fault is deactivated; a plurality of current sensor means, each respective one of said current sensor means coupled to a separate respective semiconductor switch to sense the instantaneous current in the respective motor phase winding, the output of each of said current sensor means, respectively, coupled to an input of the AND gate of the corresponding phase control circuit, each respective one of said current sensor means generating a low logic level output signal to the AND gate of the corresponding phase control circuit whenever the respective instantaneous phase current exceeds a regulated current limit; and a plurality of current differential sensor means, each respective one of said current differential sensor means coupled to a separate respective motor phase winding for detecting any difference in current flow between the two leads of each respective phase winding of the corresponding phase, the output of each of said current differential sensor means, respectively, coupled to an input of the AND gate of the corresponding phase control circuit, each respective one of said current differential sensor means generating a low logic level signal output to the AND gate of the corresponding phase control circuit when any difference in current flow between the two leads of each respective phase winding of the corresponding phase is detected. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
-
-
15. A multiphase motor drive including a fault management system for detecting motor phase faults and isolating any detected fault by deactivating the faulted motor phase to allow motor operation to continue through the remaining phases, comprising:
-
a multiphase switched reluctance motor employing unidirectional current excitation, each phase of said motor comprising two stator poles and a phase winding having two motor leads; an inverter comprising at least one semiconductor switch for each phase of said motor, each semiconductor switch being connected in series with the respective phase winding; a plurality of phase control circuits, said phase control circuits each comprising an AND gate coupled to the input of the respective semiconductor switch and generating a low logic level output signal when a fault is detected in the corresponding motor phase for deactivating said motor phase exhibiting a fault; a plurality of current sensor means, each respective one of said current sensor means coupled to a separate respective semiconductor switch to sense the instantaneous current in the respective motor phase winding, the output of each of said current sensor means, respectively, coupled to an input of the AND gate of the corresponding phase control circuit, each respective one of said current sensor means generating a low logic level output signal to the AND gate of the corresponding phase control circuit whenever the respective instantaneous phase current exceeds a regulated current limit; and a plurality of current differential sensor means, each respective one of said current differential sensor means coupled to a separate respective motor phase winding for detecting any difference in current flow between the two leads of each respective phase winding of the corresponding phase, the output of each of said current differential sensor means, respectively, coupled to an input of the AND gate of the corresponding phase control circuit, each respective one of said current differential sensor means generating a low logic level signal output to the AND gate of the corresponding phase control circuit when any difference in current flow between the two leads of each respective phase winding of the corresponding phase is detected. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
-
-
29. A method for starting a multiphase variable reluctance motor, including a rotor and a stator, when the rotor is stopped in a dead zone created by a faulted phase, said motor having at least one operating phase which, with said rotor in said dead zone, cannot generate sufficient positive torque for rotation in a pre-selected direction, said method comprising:
-
activating the operating phase to generate negative torque for rotation in the direction opposite to said pre-selected direction; moving the rotor out of the dead zone; and reversing the direction of torque generation by the operating phase, thereby rotating the rotor in the pre-selected direction.
-
-
30. A method for detecting and isolating motor phase faults in a multiphase switched reluctance motor, said motor having at least one operating phase through which motor operation is continued, each phase of said motor comprising two stator poles and a phase winding having two motor leads for connecting the phase winding in series with at least one respective semiconductor switch, said method comprising:
-
sensing the instantaneous phase current in each respective phase winding; comparing each respective instantaneous phase current to a predetermined reference current to detect the current differential between each respective phase current and said predetermined reference current; determining whether each respective current differential exceeds a predetermined current differential level; and deactivating each corresponding motor phase wherein the respective current differential exceeds said predetermined current differential level. - View Dependent Claims (31, 32, 33, 34, 35, 36)
-
Specification