Carrier Corporation

Florida State University Research Foundation, Inc.

Da Zhang

Thomas Gietzold

Bassel Al-Annouf

William Perdikakis

Ismail Agirman

Hui Li

Jeffrey John Burchill

Christopher S Czerwinski

Jeffrey M Izard

Emmanuel Collins

Richard T Pandzik

Thomas Bekasi

Subbarao Varigonda

Mark E Rollins

Salih Baris Ozturk

Weiqian Hu

A pulse width modulation (PWM) interleaving system is provided. The PWM interleaving system includes active harmonic filters (AHFs). The AHFs are disposed in parallel with each other and with a load. The AHFs are electrically coupled to a common coupling point that is electrically interposed between a grid and the load. The AHFs are configured to affect, by PWM, a characteristic of current flowing between the grid and the load. The PWM interleaving system further includes a controller operably coupled to the AHFs and configured to synchronize the PWMs of the AHFs to thereby cancel ripple currents propagating towards the grid.

Pulse width modulation interleaving

A pulse width modulation (PWM) based active harmonic filter (AHF) system including a controller configured to adjust a load on the system from a first to a second load, the first load being greater than the second load, wherein the controller is configured to adjust a frequency of the system from a first to a second frequency when the load is equal to the second load, and wherein the second frequency is greater than the first; a first harmonic compensator configured to filter a first order of harmonics of a load when the load is equal to the second load; and a second harmonic compensator configured to filter a second order of harmonics of the load in parallel with the first order of harmonics when the load is equal to the second load and frequency equals the second frequency, the second order of harmonics being greater than the first order.

Pulse width modulation upshift at partial load to improve total harmonic cancellation performance for chiller applications

A method for expulsion of a fluid inside a compressor at start-up including the steps: applying a first signal to the motor windings for a first duration of time to align the motor rotor to the initial position; applying a second signal to the motor windings to start rotation of the compressor shaft; applying a third signal to the motor windings for a second duration of time to hold the compressor shaft in place; and applying a fourth signal to the motor windings to accelerate the motor to an operational speed.

Method for soft expulsion of a fluid from a compressor at start-up

Platforms and techniques are provided for controlling a power inverter using space vector pulse width modulation (PWM) operation. The inverter converts a direct voltage (DC) power source to an alternating voltage (AC) output by controlling a set of three phase switches. A bootstrap capacitor is coupled to each switch. When each switch in the set of three phase switches is in a zero state, the coupled bootstrap capacitor can charge from the current delivered in a corresponding pulse width modulation (PWM) signal. The bootstrap capacitor can deliver stored power when a one (high) switch state is entered. Each switch can be maintained at a zero state, and thus charge the bootstrap capacitor, for at least two consecutive segments of the PWM cycle. Pre-charging of the bootstrap capacitor is ensured before power delivery is required.

Systems and methods for space vector pulse width modulation switching using boot-strap charging circuits

A method of conducting smooth motor startup is provided and includes operating a motor in an open loop control scheme at startup, operating the motor in a closed loop sensorless control scheme at a time after startup and transitioning between the open loop control scheme and the closed loop control scheme by reducing a difference between an estimated rotor angle of the motor and a commanded ramping angle of the motor.

Method for smooth motor startup

An apparatus and method for boosting output of a generator set are provided. The output of the generator set is connected to an electrical load. The apparatus includes an energy storage unit, and a power-electronic unit. The energy storage unit uses batteries and capacitors to store electric energy. The power-electronic unit measures an electrical parameter of the output of the generator set. Based on the measured electrical parameter and a predefined criterion, the power-electronic unit determines additional energy required by the electrical load. Thereafter, the power-electronic unit supplies the additional energy to the electrical load. The additional energy is drawn from the energy storage unit.

Apparatus and method for boosting output of a generator set

Different circuit-based implementations of stochastic anti-windup PI controllers are provided for a motor drive controller system. The designs can be implemented in a Field Programmable Gate Arrays (FPGA) device. The anti-windup PI controllers are implemented stochastically so as to enhance the computational capability of FPGA.

Growing community of inventors

Manchester, CT, United States of America

Da Zhang