Siemens Energy Global Gmbh & Co. Kg

Primetals Technologies Germany Gmbh

Andreas Lorenz

Rodrigo Alonso Alvarez Valenzuela

Sebastian Semmler

Clemens Jungkunz

Kilian Dallmer-Zerbe

Dominik Schuster

Ilhom Gafur

Ewgenij Starschich

Mustafa Baris Karacay

A method controls a power converter in which a target value of a control parameter is limited by at least one limiting value. The method is characterized in that the at least one limiting value is determined dynamically over time as a function of a power converter temperature. A power converter system having a control device is provided and configured to carry out the method.

Method for controlling a power converter, and power converter system having such a power converter

In a method for monitoring a high-voltage DC transmission the following are predefined: an amperage threshold value for an amperage of the high-voltage DC transmission, at least one interval length for time intervals and, for each predefined interval length, a change threshold value for a change in the amperage averaged over time intervals of the interval length. The amperage for each terminal of the high-voltage DC transmission is determined, and a change in the amperage averaged over time intervals of the interval length is determined for each predefined interval length. A DC error is determined if the magnitude of the amperage of at least one terminal is greater than the amperage threshold value or if, for an interval length, the magnitude of the averaged change in the amperage of at least one terminal is greater than the change threshold value predefined for the interval length.

Monitoring of a high-voltage DC transmission

A hydraulic cylinder unit (1) having a hydraulic cylinder (2), a piston (3) which can be moved in the hydraulic cylinder (2), and a servo valve (7). The piston (3) separates working volumes (5A, 5B) of the hydraulic cylinder unit (1) from one another. The servo valve (7) is connected to a hydraulic pump (8), a tank (9), and the working volumes (5A, 5B). The servo valve (7) is supplied with a pump pressure (pP) via the hydraulic pump (8). The tank (9) has a tank pressure (pT). The servo valve (7) is adjusted to a defined valve position (y). A piston position (z) of the piston (3) in the hydraulic cylinder (2) and working pressures (pA, pB) which are applied to the working volumes (5A, 5B) are detected. An analysis device (12) ascertains a leakage coefficient (&#x3c9;) of the hydraulic cylinder unit (1) using the piston position (z), the working pressures (pA,pB), the valve position (y), the pump pressure (pP), and a value which represents the tank pressure (pT) in connection with time-invariant parameters of the hydraulic cylinder unit (1).

Simple leakage detection in a hydraulic cylinder unit

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Erlangen, Germany

Andreas Lorenz