Caterpillar Inc.

Mahesh Sitaram Illindala

Dachuan Yu

Jackson Wai

Jesse R Gerdes

Seok-hee Han

Michael Parry Liechty

Osama Mohammad Alkhouli

Varsha Sunkara

Matthew Thomas Muller

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

A hybrid power system is disclosed. The hybrid power system may include a primary power source configured to provide a primary power, and an energy storage device coupled to the primary power source, the energy storage device configured to store excess primary power provided by the primary power source. The hybrid power system may further include a variable speed genset, the variable speed genset including a secondary power source configured to operate at a variable rotor speed to provide a secondary power responsive to power requirements of a load. The hybrid power system may also include a central controller communicatively coupled to the primary power source, the energy storage device, and the variable speed genset, the central controller configured to control the primary power source, the energy storage device, and the variable speed genset based on the power requirements of the load.

Hybrid power system with variable speed genset

A control system for a power inverter is disclosed. The power inverter may be configured to supply power to a grid. The control system may include a plurality of output voltage sensors and a plurality of output current sensors configured to measure output line voltages and output line currents of the power inverter. The control system may further include a controller coupled to the power inverter. The controller may be configured to provide a control signal associated with a disturbance frequency to the power inverter. The controller may be further configured to determine an output power of the power inverter based on the output line voltages and output line currents, and determine an amplitude of oscillation in the output power caused by the disturbance frequency. The controller may also be configured to detect an islanding condition, if the amplitude of oscillation is below a threshold. The control system may further include an interface circuit coupled to the controller and configured to disconnect the grid from the power inverter if the islanding condition is detected.

Power inverter control for grid-tie transition

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Dunlap, IL, United States of America

Mahesh Sitaram Illindala