General Electric Company

Ge Grid Solutions LLC

Hao Tu

Zheyu Zhang

Kenneth McClellan Rush

Luca Tonini

Ramanujam Ramabhadran

Tomas Sadilek

A control circuit for a power converter is provided. The control circuit includes a pulse width modulator, a current feedback loop, a bus voltage feedforward path, and a logic circuit. The pulse width modulator generates a control signal for the power converter to regulate a load current. The current feedback loop controls the pulse width modulator to converge the load current to a demanded current. The bus voltage feedforward path measures a bus voltage supplied to the power converter at an input bus and, in combination with the current feedback loop, control the pulse width modulator to regulate the load current based on the bus voltage. The logic circuit collects load current measurements and determines, based at least partially thereon, a voltage variation event has occurred on the input bus, and disables the control signal for the power converter in response to determining the voltage variation event has occurred.

Control circuit and method for bus voltage variation in power converters

A multilevel converter system is provided. The system includes a converter and a converter controller interfaced with the converter. The converter controller includes a voltage loop, a current loop, and a voltage compensation loop. The voltage loop is configured to receive first and second voltages from the first and second segments of the converter and a reference voltage. The current loop is configured to receive a current output of the converter, a reference current, and a balancing reference current. The voltage compensation loop is configured to receive the first and second voltages and a sign signal. The converter controller is configured to generate first and second pulse-width modulation (PWM) signals using output signals from the current loop and the output compensation signals from the voltage compensation loop. The PWM signals are configured to control the switches of the converter and to balance the first voltage with the second voltage.

Voltage balance systems and methods for multilevel converters

A converter includes a DC bus, a first DC-DC converter, a second DC-DC converter, and a plurality of circulating current suppression circuits. The first DC-DC converter is coupled to the DC bus and includes a first plurality of switches. The second DC-DC converter is coupled to the DC bus in parallel with the first DC-DC converter. The second DC-DC converter includes a second plurality of switches. The plurality of circulating current suppression circuits are coupled to the DC bus and are further respectively coupled to the first DC-DC converter and the second DC-DC converter. Each of the plurality of circulating current suppression circuits has a resonant frequency at or around a switching frequency for the first and second pluralities of switches. The plurality of circulating current suppression circuits is configured to suppress current at or around the switching frequency and pass at least direct current.

Paralleled DC-DC converters with circulating current suppression circuit

A multilevel converter system is provided. The multilevel converter system includes a multilevel converter and a short-circuit protection circuit. The multilevel converter includes a first segment and a second segment electrically connected to the first segment, wherein the first and second segments are each configured to convert a first current to a second current. The first segment includes a plurality of first switches. The second segment includes a plurality of second switches. The short-circuit protection circuit is electrically connected to the multilevel converter, wherein the short-circuit protection circuit includes at least one electrical component that is electrically connected in parallel with at least one of the plurality of first switches and the plurality of second switches. The short-circuit protection circuit is configured to protect the plurality of first switches and the plurality of second switches from a short-circuit current during a short-circuit condition.

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Raleigh, NC, United States of America

Hao Tu