Our system solutions partner Condensator-Dominit GmbH shows in an interesting application report how the dynamic mains voltage regulator OSKAR in combination with a high-pass filter can ensure the energy supply in sensitive areas of a hospital:
Case study: Hospital (Healthcare)
Our system solutions partner Condensator-Dominit GmbH shows in an interesting application report how the dynamic mains voltage regulator OSKAR in combination with a high-pass filter can ensure the energy supply in sensitive areas of a hospital:
Voltage quality with OSKαR ®
Three-phase active mains voltage regulator for highly dynamic correction of symmetrical and asymmetrical voltage dips and/or phase asymmetries in the electrical power supply.
Local conditions
Clinics and hospitals use a variety of highly sensitive medical devices for diagnosis or patient monitoring. Some of this medical equipment provides important information, for example, for planned operations or helps provide the best possible treatment to patients. Many of these medical devices are expensive to manufacture, purchase, and maintain, and often place high demands on the quality of their voltage and power supplies. This occurred with a state-of-the-art medical device purchased by a hospital for radiation treatment, which frequently experienced uncontrolled shutdowns, forcing treatment to be interrupted.
Customer problem
Voltage drop (reduction of the effective value)
Voltage drop (reduction of the effective value)
The medical equipment purchased for radiation treatment was relatively sensitive to electrical grid fluctuations. According to the manufacturer's specifications, only minor deviations in the supply voltage were permitted, "only" +/- 51 volts from the formal nominal value (UN = 400 V).
Customer requirement
To ensure trouble-free operation of the medical equipment, a system was sought that would respond quickly and effectively to power fluctuations, ensure continuous availability with low power losses, and require little maintenance.
Our solution
The customer's requirements were fully met. A system was installed that ensures safe and trouble-free operation, consisting of an OSKαR® dynamic mains voltage regulator and a passive high-pass filter (HP). The combination of the OSKαR® dynamic mains voltage regulator and the passive high-pass filter (HP) significantly counteracts both "slow" effective voltage changes (amplitude reduction) and transient (short-term) voltage events (dip/spike). OSKαR® is a three-phase active mains voltage regulator for the highly dynamic correction of symmetrical and asymmetrical voltage dips and/or phase asymmetries in the electrical power supply. Voltage dips of up to 30 μs, e.g., caused by faults in the power supply network or by large load connections, are fully corrected by the use of OSKαR®.
The installed HP filter is a passive, voltage-controlled filter system with a reciprocal impedance characteristic – meaning that the filter impedance decreases steadily with increasing frequency (order) (a "1/n" characteristic). This makes it possible to specifically influence the complex grid impedance (higher-level grid, feed-in transformers, cables, etc.) across a broad bandwidth (particularly in the higher frequency range) using the filter and effectively combat any existing harmonic voltage levels (interference variables) across a wide frequency range.
Effective voltage curve at the input (mains side) and at the output (load side) of OSKαR®:
Impedance-frequency characteristic (“IFC” curve) of the resulting
Impedance of the hospital network:
(the mains impedance is shown without and with the HP filter switched on)
Grid conditions before the measure was activated:
(voltage level)
Network conditions after activation of the measure
(voltage level)
Voltage curve before the measure is activated:
