Nutech Ventures

Liyan Qu

Wei Qiao

Taesic Kim

Haosen Wang

Jun Wang

Fa Chen

Ze Wang

Zhe Zhang

A wind turbine generator fault detection method is described. The method includes obtaining a first signal from a generator of a wind turbine and a second signal from a vibration sensor coupled to the wind turbine, the first signal representing an output current of the generator, and the second signal being a time-sampled signal representing vibrations of a bearing in the wind turbine. Determining a shaft rotation frequency signal from the first signal, the shaft rotation frequency signal representing a time-varying rotational speed of a shaft of the wind turbine. Resampling an envelope of the second signal based on the shaft rotation frequency signal to provide a third signal, the third signal being an angular sampled signal. Detecting, by the at least one processor, a fault in the bearing of the wind turbine by identifying a characteristic signature of a bearing fault in the third signal.

Detecting faults in wind turbines

A method for power management of a multi-cell battery includes identifying a desired power value and voltage value, determining a battery voltage value and a battery current value for a battery, determining a number of battery banks from a plurality of battery banks to use for the battery, where each battery bank includes one or more battery cells (or battery modules), checking availability of each of the one or more battery cells (or battery modules), selecting one or more battery banks from the plurality of battery banks, where the selection of a battery bank is based on the availability of the battery cells (or battery modules) included in the battery pack, and a quantity of the selected battery banks is equal to the determined number of battery banks, and connecting the available battery cells (or battery modules) in the selected one or more battery banks to form the battery.

Rechargeable multi-cell battery

Magnetic flux valves can be used in electromagnetic (EM) power converters to electronically control output signals of the EM power converters. An input signal is provided to an EM power converter that includes two or more core sections in which at least one core section includes a magnetic flux valve having an adjustable reluctance. The EM power converter has one or more primary windings and one or more secondary windings wound around one or more core sections. One or more control signals are provided to the one or more magnetic flux valves to control a reluctance or reluctances of the one or more magnetic flux valves, affecting magnetic coupling between the primary and secondary windings. An output signal is generated, in which the output signal is a function of the input signal and the one or more control signals.

Electromagnetic power converter

A scalable universal space vector pulse-width modulation (SVPWM) scheme for multilevel inverters is disclosed. In the disclosed SVPWM scheme, the modulation triangle is quickly identified based on a coordinate transformation from an &#x3b1;-&#x3b2; coordinate system to a 120&#xb0; oblique coordinate system. Then, the duty cycles and switching states of the three vertices of the modulation triangle are determined by simple algebraic computations. In a switching period, any vertex of the modulation triangle can be flexibly selected as the start point to optimize the switching sequence with flexibly adjustable duty cycle(s) for the redundant switching state(s) according to specific applications.

Scalable universal space vector pulse width modulation scheme for multilevel inverters

The aging of an electronic component in an electronic power converter can be monitored based on two or more case temperature measurements. A power electronic device is enclosed in a package having a baseplate, in which the power electronic device generates heat during operation and the baseplate transfers heat to a heat dissipating device or a cooling device. Sensors measure temperatures at first and second locations on a surface of the baseplate. A data processor calculates a value for a first parameter based on the temperatures at the first and second locations, in which the first parameter is indicative of an aging process of the power electronic device, and generates a first signal based on a comparison of the calculated value and a first predetermined threshold. The data processor calculates a value for a second parameter based on the first parameter value, a predetermined look-up table, and the temperatures at the first and second locations, in which the second parameter is indicative of another aging process of the semiconductor switching devices, and generates a second signal based on a comparison of the calculated value and a second predetermined threshold.

Monitoring aging of power semiconductor devices based on case temperature

This disclosure features an apparatus including a motor controller to generate control signals to control an electric motor. The motor controller includes a first saturation controller to generate a first saturation controller output based on feedback signals associated with the electric motor. The motor controller further includes a duty ratio modulator coupled to the first saturation controller. The duty ratio modulator is configured to determine activation times for a set of voltage vectors based on the first saturation controller output. The motor controller is configured to generate, at each switching cycle, a control signal based on the set of voltage vectors and the activation times for the set of voltage vectors, and provide the control signal for controlling the electric motor.

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Lincoln, NE, United States of America

Liyan Qu