Abstract: An electrical accumulator unit wherein an energy storage device is utilized in conjunction with an actively controlled bidirectional power converter to provide auxiliary power to an electrical network is disclosed.

Abstract: An adaptive method and device for identification and compensation of errors in resolver output signals which can increase the accuracy of position estimates of the resolver angle is disclosed. The method utilizes the ideal orthogonal relationship of two resolver output devices to determine an error factor. The error factor is then used to correct the resolver position estimate.

Abstract: A method and apparatus are presented to facilitate simulation of complex systems on multiple computing devices. Model authors can specify state-related information to be exported for viewing or access by other applications and models. Subsystem models may be written to enable connection with other subsystem models via controlled interfaces, such as by defining state-related information for export and providing for a particular use of data imported from other models to which a subsystem model is connected. In some embodiments, a consistent distributed simulation API enables cross-platform, multi-device simulation of complex systems, wherein the proprietor of each subsystem simulation can keep its implementation secret but accessible to others.

Abstract: A system, method, and apparatus select state variables for, build state equations of, and simulate time-domain operation of an electronic circuit. The circuit is modeled with three branch types (inductor, resistor, voltage source in series; capacitor, resistor, current source in parallel; and switch), including four pre-defined switch types (unidirectional unlatched, bidirectional unlatched, unidirectional latched, and bidirectional latched). Automated analyses determine efficient state variables based on the currently active circuit topology, and state equations are built and applied. Switching logic determines when switch states change, and state equations for the new topology are either drawn from a cache (if the topology has already been processed) or derived anew. The switch control signals may be combined into a single switching variable, defined as a function of the state output.

Abstract: Power electronic based power and propulsion systems are used in a wide variety of applications including locomotives, hybrid electric vehicles, aircraft, spacecraft, and ships. In general, the power electronic loads in such systems have tightly regulated outputs which causes them to behave as constant power loads exhibiting negative input impedances in a small signal sense. Such systems can be prone to negative impedance instability. The present invention mitigates negative impedance instability without the introduction of any passive or active devices into the system by providing nonlinear modulation of the power into the power electronic load.