Drives for the global market
New generation drives prove their worth in the chemical process engineering

In companies manufacturing on a global footing, new facilities or upgrades to existing plants need to be well thought-through and costed. Suppliers who themselves rank as “global players” and provide a comprehensive service offer which includes maintaining spare parts and customer services bring benefits here. This is exemplified by a new generation of frequency converters.

Like every other company in the chemicals industry, at Bayer too the use of frequency converters to control engine speed is making drive engineering more efficient. The variable speed means that processes typically found in the sector, such as transporting and dosing products, can be controlled much more precisely than when using mechanical control devices, with shorter reaction times. Furthermore, variable-speed operation protects the mechanism of the whole drivetrain due to gentle ramp-up and ramp-down, and it prevents compression waves in the pipe system, for example.

Using frequency converters, it is possible to avoid unfavorable operating conditions such as cavitation, gas or particles being transported along with the product, supersonic shock waves or vibrations. Not the least of its merits is the fact that variable-speed operation delivers major energy-savings when compared with fixed-speed motors on applications with a quadratic load moment, i.e. dynamical type compressors such as pumps and fans. Depending on the characteristic curve for the plant, these savings can be up to 50 per cent. Due to the significant economies involved, purchasing a frequency converter often pays for itself after only a few months. For drive requirements which are primarily concerned with saving energy and process precision, working in tandem with a higher-level automation system, the Sinamics G150 frequency converter—like the Micromaster 440—proves particularly suitable. These Siemens devices are specially designed for drive requirements where there is no regenerative feedback, in other words for typical “energy-saving applications” with a quadratic pattern of moments as in pumps and fans, but also for constant moment drives such as extruders or mixers. Being a member of the Sinamics drive family, the G150 series similarly benefits from the wide-ranging advantages of this new generation of drives.
The key advantages of the Sinamics family of drives are their standardized and simple planning, commissioning and operation. One example of this is the highly-versatile engineering tools: “Sizer” for project planning and “Starter” for commissioning and diagnosis. These software tools replace the need for additional manuals. Sinamics devices where high performance is required, such as the G150, come equipped with the AOP 30 operator panel, with its self-explanatory texts in the menu navigation which are presented in plain text via the graphic display.
A comprehensible approach to operating the equipment
Sinamics G150 drives can be preconfigured at the Siemens plant to suit the functions the drive is to perform, making them particularly easy to commission and operate. Thanks to the comprehensible approach to how it operates, the user only needs to focus on the functionalities he really needs. The clear and comprehensible design makes the device robust and reliable. It is also noteworthy for its modular build and easy accessibility. As a result, in the event that servicing is required the modules can be replaced with very limited manual intervention. Noise during operation, even at full speed, remains below 69 db(A), including on cabinet units with outputs of several hundred kW. Interfacing the devices with higher-level process control systems such as the Simatic PCS7 is made simple thanks to the standard Profibus interface.
Chemical industry requirements satisfied in full
Designed with the chemical industry in mind, Sinamics G150 devices, like the Micromaster 440, satisfy every requirement for that industry. With the chemicals sector in mind, they come equipped with Namur terminal strips and Namur functionalities. In addition to the Namur terminal strip, it is possible to fit the Profibus Profidrive 4.0 profile server in the “process engineering” operating mode.
At companies like Bayer, the Sinamics devices are fitted with both the Namur terminal strip and the Profibus Profidrive 4.0 profile server in the “process engineering” operating mode. This is because its production plants use both operating modes. Operation and monitoring is carried out primarily via the Profibus Profidrive 4.0 profile server, whilst operations using the conventional Namur terminal strip are also possible. There is similarly a guarantee of safe electrical isolation using a PELV (protective extra low voltage) system.
To limit the normal steep voltage edges found on IGBT intermediate circuit voltage converters and the cable/cable voltage on the engine, LC output filters or dU/dt filters are provided; these restrict the voltage gradient to values below 500 V/µsec. In addition, the cable/cable voltage is limited to values within the tolerances recommended by VIK/Namur, even for long engine cables. Referenced to a 690 V network voltage, these are 1350 V. An EMC filter for a second environment category C3 pursuant to EN61800-3 is installed as standard on equipment finishes for TN networks. The power cut-off on the frequency converter is supplied by upstream fuse protection, or above 800 A by a power switch.
Sinamics G150 drives are offered as standard with IP 21 protection. The cabinet units can be supplied as options with up to IP 54 protection.
From Dormagen to Caojing — in use worldwide
At Bayer, Sinamics G150 are used at its Leverkusen, Dormagen and Krefeld/ Uerdingen sites in the Lower Rhine region, in Antwerp (Belgium), in Map Ta Phut (Thailand) and at the Caojing plant in China. In terms of applications, the uses mainly involve pumps, compressors, fans, mixers, extruders and equipment for transporting solid matter during chemical process engineering. The Sinamics G150 range covers the major part of all standard high-performance drive functions in the chemical industry, in voltage classes from 400 to 500 to 690 V, and for outputs of up to 1500 kW.
For coordinated drives where the liberated brake energy needs to be fed back to the grid (e.g. conveyor belts, foil/film machines, chemical fiber plants and packaging machines), however, different Sinamics series machines are required: Sinamics S150 cabinet units and Sinamics S120 cabinet modules cover four-quadrant operation. For drive applications which require several megawatts, such as very large mixers or extruders,
the Sinamics GM150 medium voltage converter represents an economical solution.