BAUR Prüf-und Messtechnik GmbH has introduced “liona” - a portable device for measuring and locating partial discharge s during operation (online). With this device, medium- and high-voltage cables and switching stations can be tested quickly for partial discharges without major expense and disconnections. Special high-frequency current sensors (HFCT, High Frequency Current Transformers) are supplied with the measuring device for performing measurements on a live power grid. These probes disconnect the partial discharge signal in the cable screen.
The device also comes with capacitive couplers that are used for performing measurements on the housing of switching stations, for example. To acquire meaningful information in spite of the active mains operation, the device software differentiates between interference signals (e.g. caused by switching operations) and the partial discharges to be measured. This differentiation enables the DeCIFer algorithm from IPEC Ltd., the core of the software. The algorithm is the result of many years of expertise acquired by IPEC.
liona presents the result of the automatic measurement in a clear graph. This graph provides information on the level and type of partial discharges. With an iPD impulse generator - available as an option - partial discharges can be located precisely and the cable length determined even during operation. For this purpose, the impulse generator is connected to the other end of the cable line via an HFCT on the cable line. With the easy connection, measurement in minutes and the omission of cumbersome switching actions, liona completes the partial discharge measurement offline within a short duration. If partial discharges are detected in the cable line during the online measurement, performing a more detailed offline cable diagnostics using tan delta and partial discharge measurement is recommended. liona makes it easy for engineers not only during the measurement, but also during transport.
The device weighs only 12 kg and has the dimensions of normal cabin baggage. The impact-resistant and moisture-proof box allow the device, the accompanying analysis computer and the accessories to be transported safely.
