摘要:
A microcomputer-based drive system for a switched reluctance motor requires no rotor position sensor and no discrete current sensors. Phase excitation is synchronized with rotor position by indirectly estimating rotor position according to instantaneous phase inductance. Current regulation is achieved by incorporating pilot devices for current sensing into the switching devices of the power converter and by employing a fixed off-time current chopping strategy. One application is for use in a laundering machine.
摘要:
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.
摘要:
A motor system having a stationary assembly including a winding and a rotatable assembly in magnetic coupling relation to the stationary assembly. A power supply link having upper and lower rails supplied by a power supply provides power to the motor winding. The power supply link has power switches responsive to a motor control signal for selectively connecting the rails to the winding to energize the winding with a motor current whereby an electromagnetic field is produced for rotating the rotatable assembly. The power switches include a set of upper power switches and a set of lower power switches. Each of the power switches has a conducting state and a nonconducting state. The system includes a disable circuit for selectively generating a disable signal and a control circuit for generating the motor control signal to control the power switches. The control circuit is responsive to the disable signal for controlling the power switches so that the lower power switches become conducting and the upper power switches become nonconducting, or vice-versa, thereby de-energizing the winding to disable the motor. Other features are also disclosed including circuitry for commutating the motor in advance of zero crossings of the back electromotive force, correcting asymmetries in the commutation intervals and reversing the motor.
摘要:
A method and apparatus are provided for controlling the switching devices in a switched reluctance machine bridge inverter, which inverter has at least two switching devices per phase leg, during generating operation. At the start of the conduction interval for a particular machine phase, both switching devices of that phase are turned on, causing the phase current to build up. When the phase current reaches an upper hysteresis band level, both switching devices are turned off, resulting in the application of a reverse voltage across the phase winding and directing the phase current into the power source via flyback diodes. At relatively low and medium speeds, the phase current decreases until it reaches a lower hysteresis band level, at which point only one switching device is turned back on to form a freewheeling loop through that device and the corresponding flyback diode. The process repeats until the turn-off angle of the active phase is reached, at which point both switches are turned off in order to discharge the corresponding phase winding.
摘要:
A single phase permanent magnet motor includes a rotor, a stator, and a quadrature axis winding positioned out-of-phase from a main winding of the stator for generating an output signal representative of rotor angular position. An integrator can be coupled to the quadrature axis winding for phase retarding the output signal, and a comparator can be coupled to the integrator for detecting zero crossings of the phase retarded output signal to provide a commutation signal. The quadrature axis winding can be positioned about ninety electrical degrees out-of-phase from the main winding of the stator, and the integrator can be adapted to phase retard the output signal by a number of degrees which decreases as a speed of the motor increases. At low speeds the phase retard is preferably at about ninety degrees so that the phase retarded signal becomes in-phase with the main stator winding back EMF voltage. The motor may further include a rectifier coupled to the quadrature axis winding for rectifying the output signal, and a lowpass filter for filtering the rectified output signal to provide a signal proportional to velocity. Also the single phase motor is commutated for maximum torque production.
摘要:
A single phase permanent magnet motor includes a rotor, a stator, and a quadrature axis winding positioned out-of-phase from a main winding of the stator for generating an output signal representative of rotor angular position. An integrator can be coupled to the quadrature axis winding for phase retarding the output signal, and a comparator can be coupled to the integrator for detecting zero crossings of the phase retarded output signal to provide a commutation signal. The quadrature axis winding can be positioned about ninety electrical degrees out-of-phase from the main winding of the stator, and the integrator can be adapted to phase retard the output signal by a number of degrees which decreases as a speed of the motor increases. At low speeds the phase retard is preferably at about ninety degrees so that the phase retarded signal becomes in-phase with the main stator winding back EMF voltage. The motor may further include a rectifier coupled to the quadrature axis winding for rectifying the output signal, and a lowpass filter for filtering the rectified output signal to provide a signal proportional to velocity. Also the single phase motor is commutated for maximum torque production.
摘要:
A motor with positive torque parking positions. The motor includes a rotor which is rotatable about an axis of rotation and a stator in magnetic coupling relation with the rotor. The stator includes a plurality of teeth each having a radially extending shaft and an axially extending face. The faces of the stator teeth define an aperture for receiving the rotor and the faces of the stator teeth and the rotor define an air gap therebetween. Each stator tooth has a notch in its face that is approximately at least as wide as the shaft of the stator tooth so that the stator has a magnetic configuration relative to the rotor for parking the rotor in a rest position corresponding to a positive torque starting position. The motor also includes a winding on the shafts of the stator teeth and a control circuit for controlling current in the winding whereby an electromagnetic field is produced for rotating the rotor at a desired speed or torque during operation of the motor.
摘要:
Plural-stage form-wound stator pole coil windings for a switched reluctance motor utilize a greater portion of the interpole space than conventional windings, thereby increasing production of magnetic flux. In a two-stage form-wound coil winding, the first stage comprises an inner coil winding which fits directly around a stator pole. The second stage comprises an outer coil winding which fits directly around the first coil winding. All outer coil windings are applied to the stator before inserting the inner coil windings into the outer coil windings and electrically connecting the inner coil windings thereto. Torque production and output voltage are increased, resulting in a highly efficient motor.
摘要:
An on-line RFP procurement auction system with bidder sub-auctions for both repair and salvage of damaged property, using a telecommunications network accessible by network members including requesters, repair bidders, and salvage bidders, for processing an RFP for goods and services through at least one server and operating software. The system includes a database for each category of goods and services offered or desired by network members; software for requesters to generate RFPs for goods or services that include photographic and alpha-numeric RFP data; software for transmitting the RFPs to the server; capacity for e-mail and wireless distribution of RFP notices to bidders who have requested notices within selectable categories of RFP's; capacity to enable a repair bidder to submit an encrypted bid to the server; and capacity within the server for generating a list of all responsive bids and e-mailing the same to the requester after conclusion of an auction.
摘要:
A motor with positive torque parking positions. The motor includes a rotor which is rotatable about an axis of rotation and a stator in magnetic coupling relation with the rotor. The stator includes a plurality of teeth each having a radially extending shaft and an axially extending face. The faces of the stator teeth define an aperture for receiving the rotor and the faces of the stator teeth and the rotor define a air gap therebetween. Each stator tooth has a notch in its face that is approximately at least as wide as the shaft of the stator tooth so that the stator has a magnetic configuration relative to the rotor for parking the rotor in a rest position corresponding to a positive torque starting position. The motor also includes a winding on the shafts of the stator teeth and a control circuit for controlling current in the winding whereby an electromagnetic field is produced for rotating the rotor at a desired speed or torque during the operation of the motor.