Abb Schweiz Ag

Siemens Aktiengesellschaft

Ioannis Tsoumas

Tobias Geyer

Peter Muszynski

Lennart Harnefors

Mario Schweizer

Frederick Kieferndorf

Peter Köllensperger

Georgios Darivianakis

Manuel Vetterli

Eduardo Rohr

Wim Van Der Merwe

Ralph Mario Burkart

Wim Van-der-Merwe

Christian Meier

Daniel Ulmer

The present disclosure provides a method for controlling an energy conversion system. The system includes a rotating electrical machine, a machine-side converter, a DC-link, and a grid-side converter. The method includes modulating the machine-side converter for converting an AC voltage of the rotating electrical machine into a DC voltage supplied to the DC-link, and modulating the grid-side converter to convert a DC-link voltage at the DC-link into an AC output voltage to be supplied to an electrical grid, wherein the machine-side converter is modulated with first optimized pulse patterns, which have been optimized such that a peak value of the DC-link voltage or of a DC-link voltage component of the DC-link voltage is constrained to a predetermined value.

Method for controlling an energy conversion system, energy conversion system, controller, computer program, and computer-readable medium

Described herein is a method of operating a power electronic converter device for an electrical power conversion system. The power electronic converter device includes a converter circuit including an input side, an output side, a first converter, and at least one second converter. The second converter includes at least one floating cell with a DC intermediate circuit and semiconductor devices. The method includes: switching the semiconductor devices of the floating cell at switching instants determined with optimized pulse patterns or carrier-based pulse width modulation; determining a fundamental voltage component for the floating cell; and generating the fundamental voltage component in the actual voltage of the floating cell by modifying the switching instants, such that a voltage Vof the DC intermediate circuit is lying in a given reference voltage range for balancing the DC intermediate circuit of the floating cell.

Method for operating a power electronic converter device with floating cells

In one embodiment, a method of operating a power electronic converter device for an electrical power converter system is provided. The power electronic converter device includes a converter circuit, a first converter, and a second converter. The first converter and the second converter are switch with a switching pattern such that the first converter and the second converter generate voltages with stepwise voltages changes and an output voltage of the power electronic converter device results from a superposition of the voltages of the first converter and the second converter. The switching pattern includes switching instants for the second converter such that the voltage of the second converter leaves the fundamental voltage component of the voltage of the first converter unchanged, such that the second converter does not generate a fundamental component of the output voltage.

An electrical converter includes a main converter for generating a first output voltage and a converter cell for converting the first output voltage into a second output voltage. A method for operating an electrical converter includes: receiving a reference voltage for the electrical converter; pulse width modulating the reference voltage with a first modulation frequency for generating a first switching signal for the main converter; switching the main converter with the first switching signal to generate the first output voltage; estimating the first output voltage from the first switching signal; determining a voltage error by subtracting the estimated first output voltage from the reference voltage; pulse width modulating the voltage error with a second modulation frequency, which is higher than the first modulation frequency, for generating a further switching signal for the converter cell; and switching the converter cell with the further switching signal to generate the second output voltage.

Cascaded pulse width modulation converter control

A method for controlling a converter system includes: determining, with a first controller stage, an output voltage reference for the converter system; generating, with the first controller stage, switching commands for a main converter based on the output voltage reference, such that the main converter converts an input voltage into an intermediate voltage provided at an output of the main converter and following the output voltage reference; and generating, with a second controller stage, switching commands for a floating converter cell connected to the output of the main converter, such that the floating converter cell converts the intermediate voltage into an output voltage provided at an output of the floating converter cell, wherein the floating converter cell comprises a cell capacitor and a semiconductor switch arrangement for connecting and disconnecting the cell capacitor between the output of the main converter and the output of the floating converter cell.

Two stage control of converter system with floating cells

In a method for reducing noise of a motor fed by a converter, a magnetic flux in the motor is changed for reducing a fundamental oscillation and a harmonic oscillation of the magnetic flux, and a degree of control and/or a pulse frequency of the converter is changed so as to change a harmonic oscillation of the magnetic flux.

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Zurich, Switzerland

Ioannis Tsoumas