Supplying district heating
To facilitate drive or control of electrically operated fittings in power stations or supply networks, Regeltechnik Voigt GmbH from Eibau in Germany's region of Saxony is at the forefront of technology. To build the new district heating distribution network in the city of Dresden they read the sensor signals with the AS-Interface double slave from ICS and found all their expectations in the world's easiest bus system to be proven.
It all started with "Voigt's washing machine in a tub" in 1930. This device saved the housewives the hard manual labour with plunger and washboard, and became a legend in and around Eibau in the Oberlausitz region of Saxony. Not least because of the builder, the grandfather of today's owner, who improved the propulsion technology continuously even at that time.
A generation later the name Voigt stood proud above a prosperous work shop in former German Democratic Republic. The shop repaired industrial valves and Klimakt actuators for fittings. And after the German reunion in 1991 today's Regelungstechnik Voigt was founded.
Everybody who has met the current CEO Jürgen Voigt, will know his quality to bring together traditional well proven technology and modern inventions. The good old engineering philosophy 'no way is there no way' and the benefits of modern technologies, such as AS-Interface fuse together into a successful unit. Together with his team Voigt plans and mounts facilities in a range of power and other community supplies. These require electrically powered fittings for service or control from power plants or pumped storage hydro power stations to water, sewage or community heating facilities.
In the current project the district heating distribution facilities for the supply network of DREWAG - Stadtwerke Dresden GmbH - had to be re-equipped. In most of the decentralised distribution locations there are two to eight electrically powered fittings. These are equipped according to their purpose with limit and torque switches as well as with analog signals for the feedback transducers that are required for the valve control. These signals are converted to AS-Interface by double slave modules of ICS. Then the signals are sent via AS-Interface to a PLC. These double slave modules have eight binary inputs and an analogue input (4..20mA). Measuring at only 90x60x20mm it fits into the connection boxes of the fitting actuators. The modules are fully potted protecting them against moisture and other environmental insults. For each actuator an AS-Interface operating device is mounted on site, containing four pushbuttons and signaling lights.
By this concept Sebastian Kretschmer, in charge of automation technology at Voigt, was hoping for several benefits at once. It can be used in modular units up to 16 actuators. It allows the efficient connection to existing remote control technology. It is compatible with the fittings of different manufacturers without additional wiring efforts. It offers the use of small control cabinets for all the actuators of one station. The position feedback of the actuators can be measured conventionally, or alternatively seen on a touch display.
Due to its flexibility, simple expandability and compactness the AS-Interface has met the expectations of Voigt and Sebastian Kretschmer in practical as well as in economic terms. This is why he will continue to use AS-Interface for the next steps of the project.