Abstract:
Techniques to limit electrical power when forming an electrical grid using an active front end unit having an inverter that is coupled to a capacitor (and inductor) that is coupled to an electrical grid. For example, to limit power, the integration of a commanded frequency of the system can be limited to be within a specified phase delta of a measured phase angle of an electrical grid voltage vector. The calculation from power limit to phase delta can be done when the phase of the electrical grid voltage vector has been determined to be accurate and is calculated based on the measured capacitor voltage, grid voltage, and the estimated voltage drop across the output components of the system.
Abstract:
A system and method for torque compensation in a switched reluctance (SR) machine disposed on a machine is disclosed. The system may comprise a SR machine, an inverter and a controller. The controller is in operable communication with the inverter and is configured to determine a commanded main current associated with energization by a main current of a first portion of the plurality of windings for a controlling phase, and determine a commanded parasitic current associated with energization by a parasitic current of a second portion of the windings in a non-controlling phase. The controller is further configured to determine an offset current based on the commanded parasitic current, and determine a target current based on a first sum of the commanded main current and the offset current, and command the inverter to actuate the target current in the first portion of the windings during the controlling phase.
Abstract:
A system and method for torque compensation in a switched reluctance (SR) machine disposed on a machine is disclosed. The system may comprise a SR machine, an inverter and a controller. The controller is in operable communication with the inverter and is configured to determine a commanded main current associated with energization by a main current of a first portion of the plurality of windings for a controlling phase, and determine a commanded parasitic current associated with energization by a parasitic current of a second portion of the windings in a non-controlling phase. The controller is further configured to determine an offset current based on the commanded parasitic current, and determine a target current based on a first sum of the commanded main current and the offset current, and command the inverter to actuate the target current in the first portion of the windings during the controlling phase.
Abstract:
An electrical inverter may include a plurality of phase modules to provide a plurality of phase outputs. Two or more of the plurality of phase modules may share a common insulated-gate bipolar transistor.
Abstract:
A control system for a switched reluctance (SR) machine having a rotor and a stator is provided. The control system may include a converter circuit in electrical communication between the stator and a common bus, and a controller configured to monitor a bus voltage of the converter circuit and a phase current of the SR machine. The controller may be configured to determine a phase voltage based on one or more of main pulses and any diagnostic pulses, determine an estimated flux based on the phase voltage and an associated mutual voltage, determine a rotor position based at least partially on the estimated flux, and control the SR machine based on the rotor position and a desired torque.
Abstract:
A method for determining rotor position of a switched reluctance (SR) machine having a rotor and a stator is provided. The method may include injecting a test pulse into one or more idle phases of the SR machine, determining a decoupled flux value based at least partially on a total flux value corresponding to the test pulse and a mutual flux value, and determining the rotor position based at least partially on the decoupled flux value.
Abstract:
A method of controlling a motor is provided. The method may determine one of a switching period, a fundamental cycle, and a current target per phase leg of the motor having at least one high voltage transition point; determine a dwell period to be enforced at the transition point between an engagement of a first switch of the phase leg and an engagement of a second switch of the phase leg where each of the first switch and the second switch may be selectively engageable between a first state and a second state; engage the first switch from the first state to the second state at the transition point; and engage the second switch from the first state to the second state after the transition point and upon expiration of the dwell period.
Abstract:
A method of estimating an initial rotor position of a switched reluctance (SR) machine having a rotor and a stator is provided. The method may comprise the steps of driving a phase current in each of a plurality of phases of the SR machine to a predefined limit, performing an integration of a common bus voltage associated with each phase, determining a flux value for each phase based on the integrations, and determining the initial rotor position based on the flux values.