Caterpillar Inc.

Gregory J Speckhart

Dachuan Yu

Jackson Wai

Jesse R Gerdes

Michael S Lukich

Larry Ellis Kendrick

Mark E Hartman

Eric M Andris

Darwin R Carrell

Bryan Edward Nelson

Gregory Scott Hasler

Thomas M Sopko

James David Siegle

Jeffrey Michael Thate

Joshua C Ruedin

Joshua M Williams

Bruce Henry Hein

Ronald C Gayles

John Joseph Votoupal

Jyothiraditya Ramaswamy

Karthik Desingu

Techniques are described to smooth start a multilevel dual active bridge converter by pre-charging the capacitors present on the converter without requiring any additional hardware. Various phase shift angles determine the power delivered by the dual active bridge converter. By using the techniques, a predefined amount of time is reserved to pre-charge the capacitors until the capacitors reach a desired voltage after which time the smooth starting of the dual active bridge converter is initiated.

Start-up control for multilevel dual active bridge converter

An example transformer includes a controller that determines the currents on a power grid side of the transformer, as well as an inverter/load side of the transformer. The transformer may be of a delta-wye configuration. The controller compares the currents on the delta side of the transformer to the currents on the wye side of the transformer to determine whether the currents on either side are imbalanced. If the currents on the delta side are balanced, while the currents on the wye side are imbalanced, then the controller may determine that an open phase condition exists on the wye side of the transformer. Alternatively, if the currents on the delta side are imbalanced or if the currents on the delta side are balanced and the currents on the wye side are also balanced, then the controller determines that no open phase condition exists.

Open phase detection

The present disclosure discloses methods, systems, and non-transitory computer-readable medium for off-grid load stabilization. For instance, the method may include: receiving generator data from at least one generator and energy storage data from at least one energy store; determining, based on the generator data and/or the energy storage data, a moving average of a system load of the at least one generator; and determining, based on the generator data and/or the energy storage data, an instantaneous load value of the at least one generator. The method may further include: determining a first electronic storage dispatch (ESD) based on the moving average of the system load and the instantaneous load value of the at least one generator; and providing the first ESD to the at least one energy store.

Methods and systems for off-grid load stabilization of energy distribution systems

A variable speed genset system is provided that may include a primary power source, an electric machine, an energy storage device, a boost converter, and a controller. The electric machine may be coupled to the primary power source and electrically coupled to a load through a common bus. The boost converter may be in electrical communication with the common bus and the energy storage device. The controller may determine a State of Health (SOH) for the energy storage device, selectively engage the energy storage device to provide a first power amount to the common bus, and selectively change the operating speed of the primary power source to provide a second power amount to the common bus, the speed based on the SOH, a temperature of the energy storage device, and the load demand. The combination of the first and second power amounts substantially meet a load power demand.

Life degradation mitigation for transient response energy storage

A hybrid energy storage system (HESS) and method of controlling a HESS is provided. The HESS comprises a common direct current (DC) bus having a DC bus voltage, an energy storage device electrically coupled to the common DC bus, a power device electrically coupled to the common DC bus, and a controller in operable communication with the energy storage device, the power device and the common DC bus. The controller is configured to, when the energy storage device is charging, increase a power device charging current if an energy storage device charging current is greater than a charging limit for the energy storage device, and when the energy storage device is discharging, increase a power device discharging current if an energy storage device discharging current is greater than a discharging limit for the energy storage device. The HESS can be part of a power system.

Control of hybrid energy storage system for high pulse load

A method of determining an optimal operating speed of a variable speed genset is provided. The method may include determining whether an actual operating speed of the genset approximates a desired operating speed, the desired operating speed being predetermined based on a measured load value associated with the genset, the desired operating speed being associated with an applied offset value that is adjustable between a minimum offset value and a maximum offset value; incrementing the applied offset value of the desired operating speed to decrease the actual operating speed if the actual operating speed approximates the desired operating speed, and the applied offset value is less than the maximum offset value; and determining the desired operating speed as the optimal operating speed if the actual operating speed approximates the desired operating speed, and the applied offset value is equal to the maximum offset value.

Adaptive variable speed genset control

A method of controlling a power converter in an electric drive machine is disclosed. The method may include determining a first switching frequency and determining a second switching frequency. The method may also include comparing the first switching frequency and the second switching frequency. The method may further include selecting a power converter switching frequency from the lesser of the first switching frequency and the second switching frequency to control a power converter.

Method and system for temperature-based power converter control

A method of detecting one or more failed current sensor and estimating a phase current for the failed current sensor on a three-phase machine is disclosed. The method may include detecting one or more failed current sensor by determining if an absolute value of a sum of the phase currents of the motor is below an open circuit value. The method may also include determining which phase currents are approximately zero, for each phase current associated with each phase of the motor, if the sum of the phase currents of the motor is not below the open circuit value. The method may further include estimating the phase current for the failed current sensor by determining the phase current value for the failed current sensor, that when added to the phase currents of the remaining current sensors, will make the sum of all the phase currents equal to approximately zero.

Method and system for detecting a failed current sensor in a three-phase machine

A system is provided for controlling an electric machine. The system has a power source configured to supply electric energy to the electric machine. In addition, the system has an inverter operationally connected to the power source and the electric machine and configured to increase or decrease a rotor flux component of a voltage applied to the electric machine, while maintaining a torque component at an essentially constant level. The system further has a control device configured to determine at least one parameter of the electric machine and operate the inverter in either a first or a second mode in response to the at least one determined parameter.

Electric motor system implementing vector and slip control

An engine braking system includes a pump associated with a source of fluid, the pump supplying pressurized fluid to fuel injectors associated with the engine. An electronic controller is associated with the engine and determines a desired engine braking level as a function of various engine operating conditions and operator inputs. The engine controller produces a pump signal as a function of the desired engine braking level.

Method and apparatus for engine braking

The present invention provides a method and apparatus for determining the oil grade of an actuating fluid in a fuel system. The method includes the steps of determining an actuating fluid temperature, a pump speed, and a peak pressure or a timing event of the actuating fluid, and responsively determining the oil grade of the actuating fluid.

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Peoria, IL, United States of America

Gregory J Speckhart