Abstract: An apparatus for estimating electrical properties of an electrolyzer includes a data processing system for estimating electrical values, for example a membrane resistance, of the electrolyzer based on a difference voltage, a current, and an initial value and an attenuation time constant of a double-layer capacitance voltage of the electrolyzer during a shutdown of the electrolyzer. The difference voltage is a difference between a voltage of the electrolyzer and a total reversible voltage of the electrolyzer. The initial value and the attenuation time constant of the double-layer capacitance voltage are estimated based on values of the difference voltage when the current is zero and thus the difference voltage equals the double-layer capacitance voltage. The electrical values can be estimated even if a stepwise interruption of the current of the electrolyzer is not possible.

Abstract: A system for alkaline water electrolysis includes electrolysis cells, a hydrogen separator tank, a first piping from the electrolysis cells to the hydrogen separator tank, an oxygen separator tank, a second piping from the electrolysis cells to the oxygen separator tank, and a third piping for conducting liquid electrolyte from the hydrogen separator tank and from the oxygen separator tank back to the electrolysis cells. The system includes an ultrasound source for applying ultrasound on the liquid electrolyte contained by the first piping. The ultrasound enhances the separation of dissolved hydrogen gas from the liquid electrolyte contained by the first piping, and thus energy efficiency of the alkaline water electrolysis is improved. Furthermore, a safe control range of the alkaline water electrolysis is broadened because crossover of hydrogen gas to an oxygen side of the system is reduced.

Abstract: A system for determining a leak flow of a vacuum system of a vacuum filter includes a controller for adjusting speed of a filtration media of the vacuum filter and/or for adjusting supply rate of slurry onto the filtration media. The system includes a pressure sensor for determining pressure difference affecting over the filtration media and a layer of the slurry carried by the filtration media, and a device for determining flow rate through a vacuum pump that maintains the pressure difference. The speed of the filtration media and/or the supply rate of the slurry is/are adjusted so that the slurry is fully saturated by liquid along a whole filtration area affected by the pressure difference. Thus, fluid flow through the layer of the slurry is negligible and therefore the determined flow rate is indicative of the leak flow of the vacuum system.

Abstract: The present disclosure presents a method, a sensor comprising printed circuit board (PCB), and a sensor PCB for a capacitive sensor for sensing position or motion of a shaft comprising an electrically conducting part. The method and the sensor utilize the sensor PCB that comprises a mounting hole through which the conducting part of the shaft can be mounted, at least one capacitor electrode formed to the printed circuit board, wherein an electrode surface of the electrode extends parallel to a center axis of the mounting hole and faces the center axis.

Abstract: A control device (101) for controlling a magnetic levitation system includes a controller (103) for controlling one or more voltages directed to one or more windings of the magnetic levitation system on the basis of a deviation of a position of an object (108) to be levitated from a reference position so as to control a resultant magnetic force directed to the object. The controller selects, for each of temporally successive control periods, a control direction so that ability of the resultant magnetic force to decrease the deviation of the position is improved when the resultant magnetic force is changed in the selected control direction. Thereafter, the one or more voltages are selected in accordance with the selected control direction so as to decrease the deviation of the position by changing the resultant magnetic force. Thus, there is no need for nested control loops which are typically challenging to tune.

Abstract: The present disclosure presents a method, a sensor comprising printed circuit board (PCB), and a sensor PCB for a capacitive sensor for sensing position or motion of a shaft comprising an electrically conducting part. The method and the sensor utilise the sensor PCB that comprises a mounting hole through which the conducting part of the shaft can be mounted, at least one capacitor electrode formed to the printed circuit board, wherein an electrode surface of the electrode extends parallel to a center axis of the mounting hole and faces the center axis.