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The beginning of a new drive generation

Technical papers

SIEB & MEYER launches new frequency converter product family SD4x

Frequency converters for high-speed applications are one of SIEB & MEYER's specialties. Based on the new development platform SD4x, the company from Lueneburg is working on a new, future-proof device series. The devices support new interfaces and offer a number of additional functions. Users will benefit from higher speeds and from a significantly enhanced performance. The first step has already been taken: SD4S is the first device of the SD4x product family. This frequency converter is designed for small high-speed spindles or motors in a power range of a few hundred watts.

All frequency converters and servo amplifiers of series SD2x stand out for maximum performance at reduced system costs, low required space and a long service life. With this series, SIEB & MEYER offers its customers a wide range of standard devices. The portfolio of cutting-edge frequency converters and servo amplifiers covers a power range between 0.3 and 450 kVA and output frequencies from 0 to 8,000 Hz, which corresponds to a speed of 480,000 rpm. Different control methods and device topologies ensure to find an optimal solution for any application in the product range.

Efficient and proven – but outdated

The efficiency of the SD2x product family is proven by concrete figures. High-speed motors usually require high rotating field frequencies. The frequency converters of the SD2x family specialize in rotating field frequencies of up to 8,000 Hz and allow motor designs with more poles, which for example reduces the construction volume by up to 30 %. Another advantage of the SD2x product family is that the control procedures lead to a smaller portion of harmonic frequencies in the motor current. Losses in the frequency converters of the SD2x product family are by 50% less in comparison to competitive products and heating is reduced correspondingly. In addition, the multi-axis drive system SD2 allows an energy exchange between the individual movement axes via a common DC link and uses this potential for energy savings. Depending on the machine structure and motion profile, energy savings of up to 30 % can be achieved.

"Despite of all mentioned advantages: The SD2x product family as development platform has been on the market since 2006 and thus has reached an age that makes us as manufacturer think about the future", explained Torsten Blankenburg, CTO at SIEB & MEYER. It starts with the availability of material: SIEB & MEYER wants to guarantee its customers long product life cycles of at least 10 years. Some of the components implemented in the SD2x devices, however, will no longer be available in the mid term. The used development tools are also out of date. "Moereover, we have many ideas for the further development of our products that cannot be realized with the existing processors and memory sizes", stated Blankenburg.

New product family with increased performance

These are all good reasons for SIEB & MEYER to launch a new product family named SD4x. The SD4X devices will support new interfaces and protocols such as ProfiNet, TNC or Biss and thus will be well prepared for the future –additional features such as a real-time clock will ensure this. The key element is the significantly increased processor performance: The new 32-bit processor is up to five times faster, thus allowing a higher resolution and more precise calculations. SIEB & MEYER has also switched from a fixed-point to a floating-point arithmetic, which allows for a more flexible software design. All in all, the new processor system enables users to perform more complex tasks faster. On the hardware side, a new FPGA allows a 1.8 times faster calculation: It allows executing more complex control tasks. SIEB & MEYER has also significantly increased the memory capacity – with the 500 times larger memory there will be no bottlenecks in the foreseeable future.
For customers, this translates into a considerable performance increase: Higher switching frequencies and an enhanced control performance at even higher speeds lead to an optimized overall process.

Thanks to an integrated position controller, SD4x devices can now execute high-precise positionings. The speed and current controller have remained unchanged with regard to the SD2x series. "Our aim is to drive high-speed motors dynamically and with the smallest possible power losses", said Blankenburg. Therefore, we now support PWM switching frequencies of 24 and 32 kHz." For an even finer modulation of the sinus-wave signal, we have integrated a commutation angle control for 32, 48 and 64 kHz. The result is an almost optimum sine with nearly no harmonic currents. The power loss caused by the PWM can be reduced to a small fraction.

Easy usabililty of software and device

We have also strongly improved the usability: With drivemaster4, SIEB & MEYER provides a new version of the proven parameterization software. It is intuitive to use and its new user interface that is divided into four parts opens up entirely new possibilities. "In the previous versions, users had to open a new window for each new operation", explained Blankenburg. "In the latest version, we offer detail windows that flexibly change when you select another device." A watchlist allows subscribing for parameters of several devices at the same time – this is especially useful for multi-axis applications. Via a Data logger, users can monitor and evaluate characteristic curves over a longer period of time.

SD4S closes a gap in the lower power range

SD4S is the first device of the new product family SD4x and closes a gap within the product portfolio of frequency converters: The device is designed for high-speed spindles and motors within a power range of a few hundred watts. Application areas are e.g. dental milling machines or machines for super finishing as those required in watchmaking. Since small spindles do not come with a sufficient insulation resistance in the motors, SD4S now features a galvanic isolation of the thermal contact. An absolute novelty is the design width of 40 mm only. Just for comparison: The currently smallest device by SIEB & MEYER has a width of 70 mm. Particulary in applications with many axes and a low performance, the demand for highly compact drive systems is great. Thus, the Lueneburg experts have further reduced the construction volume.

The parameterization is realized via a default Ethernet interface that replaces the USB interface, which in industrial environments is prone to failure. Moreover, SD4S comes with programmable digital measuring system interfaces such as Biss-C, EnDat2.2 and TTL. Via a Webserver, technicians can display device information without the need of additional parameterization software. Thanks to the real-time clock, a time synchronization of an incident is possible: Users can figure out whether a failure has been caused for example by a thunderstorm.

"SD4S is the beginning of a new drive generation and the first product of our new development platform SD4x", stressed Blankenburg. "We will continuously extend the SD4S performance ranges." In the long term, SIEB & MEYER will replace all other devices of the SD2x product family. "The optimized performance, higher speeds as well as the lower motor heating without sine-wave filter – these are substantial advantages of the SD4x product family", summarized Blankenburg. The enhancements will allow improving the production quality for existing applications and, beyond that, exploring completely new fields of application."