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Pictures of the Future



Mr. Sebastian Webel
Mr. Sebastian Webel


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Werner-von-Siemens-Straße 1
80333 Munich

Pictures of the Future
The Magazine for Research and Innovation

Power Transmission

Device Spots Vulnerabilities in Power Grids

Power grid providers as well as industrial enterprises both benefit from better grid monitoring.

A new power analyzer monitors and analyzes the power grid, helps prevent downtimes and avoid damage to equipment, especially when there is a high proportion of energy generated from renewable sources.

Siemens experts estimate that blackouts cause approximately €150 billion in damage worldwide every year when production or IT is down. In Germany, downtimes are very short, an average of only approximately twelve minutes per year. But conditions are changing, due to the high proportion of renewable energy in the grid. In the past, the supply quality – that is, the constant voltage quality, availability and quality of service – was established by the equilibrium between power generation and consumption. But as the amount of energy produced from renewable sources increases, significant voltage fluctuations and uneven availability may arise.

Modern technology also impairs grid quality. Devices that consume highly variable amounts of energy produce harmonics and thus interfere with sensitive electronics. An example of such a nonlinear consumer is a frequency-controlled drive, which is a motor that adjusts its power as demand changes. Many industrial enterprises use this technology to make their production processes more energy-efficient. However, if they operate sensitive plants at the same time, they have to secure the quality in their power grids.

With these considerations in mind, Siemens has developed a new power analyzer. The device gives grid operators and industrial enterprises a solution that allows them to correctly evaluate changing loads on power grids. To accomplish this, data regarding electrical variables, such as current, voltage, frequency and power as well as harmonics, need to be collected in the grid. Based on the results of such an analysis, operators can decide on the best way to ensure supply quality. After all, poor power quality not only burdens equipment, but a failure can shut down factories, damage plants and cut off households from the power supply. Good supply quality, on the other hand, reduces downtimes and increases the life of devices on the power grid.

Locating disturbances, identifying energy savings potential

The Sicam Q200 power analyzer measures all important parameters for power quality, analyzes them and visualizes the results. In addition it can be interfaced with energy management devices.

Siemens’ Sicam Q200 power analyzer measures all important parameters for power quality, analyzes them and visualizes the results. When installed at key points in power distribution stations, transfer points, feeders for industrial plants, industrial grids, etc. the device detects current, power, voltage, frequency and harmonics. It identifies disturbances and can detect short circuits and nonlinear consumers based on measurements of current. The device also indicates whether and where damage has occurred. Operators can use the resulting data to decide whether to preventively replace a device or component.

Sicam Q200 detects the power and corresponding phase angle of harmonics. These variables make it possible to determine the precise nonlinear consumer that is distorting a current. Active filters can then be installed to compensate for the harmonics. Thanks to its power measurements, the power analyzer also helps save energy. Measured data provides detailed insights into energy consumption on the grid and thus identifies savings potential.

The power analyzer displays measured values directly on the device and transmits them to a computer in the user’s energy automation or SCADA system. The device also stores measured values for additional analyses and can transmit long-term data and certain events to a higher level control center for further analysis. The power analyzer is operated via an integrated web server, which saves money, since no additional software is needed for configuration or data evaluation.

Christine Rüth
Picture credits: from top: 1. picture getty images/Jetta Productions