Caterpillar Inc.

Jackson Wai

Jesse R Gerdes

Ahmed Khalil

James Michael Thorne

Mark E Hartman

Seok-hee Han

Sangameshwar Sonth

Carlos Eduardo Nino Baron

James David Siegle

Thuong Le

Ernesto Inoa

Carlos Nino Baron

Amara Ashfaq

Sajan Abdul

Thomas Michael Sopko, Jr

Gregory J Speckhart

Thomas M Sopko

Robert Wayne Lindsey

Jason Lee Miller

Joshua M Williams

Benjamin Paul Gottemoller

Timothy Goldammer

Bruce Henry Hein

Adam Braun

Amir Saad

Daniel E Henderson

Alexander Cameron Crosman, Iii

Rodwan Tarek Adra

Bryan G Lammers

Dachuan Yu

Robert Roy Sychra

James Allen Roal

Jyothiraditya Ramaswamy

Mahesh Sitaram Illindala

Aaron Luther Thomas

Karthik Desingu

Carlos Eduardo Nino-Baron

Jean Marcos Lobo Da Fonseca

Varsha Sunkara

Chad Brewer

Brad A Kough

Sam Han

Yash Bhatia

Capacitor voltage balancing techniques are described for a 3-level 3-level dual-active-bridge converter that controls the duration of a zero voltage state of the low voltage (LV) and medium (MV) side transformer voltages based on a voltage difference between the upper and lower capacitors of both the LV and MV sides independently, the power delivered (P), and the LV and MV DC voltages. This control varies the angle to maintain the power requirement, which induces the additional voltage drop across the transformer inductance to produce the required current to flow through the capacitors and balance the capacitor voltages.

Capacitor voltage balancing techniques for multi-level dual active bridge converter

An interface circuit to interface an energy source to a power bus of a microgrid includes a switching inverter circuit, an output filter circuit coupled between an output of the three-phase inverter circuit and the power bus, and a control circuit loop to control switching of the switching inverter circuit. The control circuit loop is coupled to the output filter circuit and the switching inverter and includes a proportional-integral oscillator-based repetitive (PIOR) controller.

Voltage source inverter control for unbalanced and nonlinear loads

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.

Techniques for limiting power using an active front end

An apparatus can include an inverter to provide an output N-phase alternating-current to an external component. When N equals two, a phase of the N phases can include an upper gate and a lower gate. The apparatus can also include a current detector configured to detect a phase current magnitude of the output alternating current. The apparatus can also include a controller coupled to the current detector and to the inverter. The controller can generate a gate command for controlling a gate of the inverter. The controller can also determine a value for a current threshold less than a shutoff current threshold for the external component. The controller can provide a protection command to turn off the upper gate of a corresponding phase of the inverter responsive to detecting that the phase current magnitude is greater than the current threshold.

Current protection to prevent overcurrent in electrical grids and motors

A work machine includes a frame, a traction system supporting the frame, a power source mounted on the frame, a switched reluctance motor, an inverter configured to control power to the motor from a power source, and a controller. The controller is configured to receive a signal indicating a desired torque and determine if the desired torque is between an upper threshold and a lower threshold. If the desired torque is between the upper threshold and the lower threshold, pulse width modulation is used to produce a PWM adjusted torque command, and the motor is commanded based on the PWM adjusted torque command. The PWM adjusted torque command is configured to cycle between the upper threshold and the lower threshold to produce the desired torque.

System and method of overcoming a dead-band in a switched reluctance motor

Power based self-sensing of a rotor position of an SR motor at mid to high speeds and low torque is achieved by an SR motor control system by comparing the motor power to an injection maximum power. A position current pulse is injected to a stator pole in response to the motor power being less than the injection maximum power. An actual stator current created by the position current pulse is compared to an estimated stator current, and a stored estimated rotor position in a memory is updated to a new estimated rotor position if the actual stator current is not equal to the estimated stator current.

Power based pulse injection control for SR self sensing

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.

Switched reluctance self sensing active pulse torque compensation

A control system that includes a converter circuit and a control device is disclosed. The converter circuit may be configured to control a phase current of a switched reluctance machine. The control device may be configured to determine an estimated flux based on a bus voltage, a phase voltage, and a mutual voltage. The control device may be configured to determine a flux threshold based on the phase current, and determine a first limit and a second limit relative to the flux threshold. The first limit and the second limit may be scaled relative to the flux threshold based on one or more of the target speed, the load demand, or the bus voltage. The control device may be configured to compare the estimated flux with the first limit, and reset the estimated flux to the second limit based on determining that the estimated flux satisfies the first limit.

Modified flux observer for switched reluctance machines

A device may receive a current measurement of a motor identifying a plurality of component currents associated with a plurality of phases. The device may determine a position estimate for the motor based on the plurality of component currents associated with the plurality of phases. The device may control the motor based on the plurality of component currents.

Switched reluctance motor control system

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.

Inverter topology

A control system for a rotary electric machine includes a controller configured to generate dynamic input current data based upon a dynamic analysis of self flux data, mutual flux data, and saturation scaling factor data. Upon generating a torque request, the controller is configured to determine a desired electrical input based upon the dynamic input current data to generate the desired output torque. The desired electrical input includes a magnitude and duration of an electrical pulse and a desired angular position of the rotor of the rotary electric machine relative to the stator of the machine. The controller determines an angular position of the rotor and generates an operating command to generate the desired electrical input at the desired angular position of the rotor to propel the rotary electric machine and generate the desired output torque. A rotary electric machine and method of operating same are provided.

System to control a rotary electric machine

A device may select an operation mode based on at least one of a motor speed, a motor transient speed, or a motor power command value. The operation mode may be selected from a group of operation modes including a single pulse mode, a continuous conduction mode, and a variable dwell continuous conduction mode. The device may control a switched reluctance motor using the operation mode.

Optimized switched reluctance phase current control in a continuous conduction mode

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.

Sensorless control of switched reluctance machines for low speeds and standstill

A control system is provided for an electric machine having a rotor and a stator. The control system has a converter circuit in electrical communication with the stator and a controller in electrical communication with the converter circuit. The controller is configured to receive a first signal indicating a torque applied to or output by the rotor and receive a second signal indicating a rotational speed of the rotor. The controller is also configured to determine at least one characteristic of a pulse signal based on at least one of the first or second signal. The controller is also configured to inject the pulse signal into one or more phases of the stator via the converter circuit according to the determined at least one characteristic. The controller is also configured to determine a position of the rotor based on the injected pulse signal.

Adjustable pulse injection in electric machine control

A system and method for estimating a position and a speed of a rotor of a Switched Reluctance (SR) machine is provided. The SR machine comprises the rotor, a stator and at least one winding. The method includes generating a diagnostic pulse having a trapezoidal shape. The method further includes injecting a diagnostic pulse into the at least one winding of the SR machine. The method further includes measuring an actual stator current flowing through the at least one winding of the SR machine. The method further includes computing an estimated stator current flowing through the at least one winding using observer-based estimation technique. The estimated stator current is compared with the actual stator current to compute an error signal. At least one of the position and the speed of the rotor is estimated based on the error signal.

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Dunlap, IL, United States of America

Jackson Wai