SD2S Frequency Converter

The Specialist for High-speed Applications

Frequency Converter SD2S – The Expert for High-speed Applications

Powerful, flexible and compact – these words describe the drive amplifier SD2S by SIEB & MEYER. Using the available drive functions synchronous and asynchronous motors with speeds up to 480,000 rpm can be driven by SD2S, especially in respect of a low motor heating in high-turning motors with small rotor volume. Furthermore, small motor temperatures are the basis for a high machining quality. Depending on the application, the operation can be carried out with or without encoder. For the operation with an encoder SD2S offers the possibility to evaluate the common encoder systems existing on the market. SD2S is connected to the higher-ranking control via analog reference values (+/-10 V), digital I/Os, RS232, USB, CAN bus, Profibus*or EtherCAT (CoE)**.

* Via SERVOLINK respectively Anybus adapter.
**CoE=CAN over EtherCAT

Easy but robust

Additionally to the basic characteristics in respect of a low motor heating SD2S offers two drive functions characterized by an easy parameterization and a robust operation for applications up to 120,000 rpm. For asynchronous motors the drive function V/f-PWM is used. By means of the V/f characteristic curve the user can carry out the graphically aided parameterization of the motor. As using the V/f characteristic curve is an established form of motor parameterization for example in grinding applications, the user can take advantage of the experience gained in this field.

The SVC drive function (Sensorless Vector Control) is provided for synchronous motors and is based on the equivalent circuit diagram usually found in the motor data sheet. SVC allows 4-quadrant operation of high speed synchronous motors and generators so that SD2S can be used for high speed applications such as turbo blowers or turbines for
utilization of process energy.


Technology Functions for Grinding Applications

Multi parameter sets – The flexibility of grinding machines largely depends on the possibility of a fast and simple use of grinding spindles. The feature of saving up to 64 motor parameter sets in the drives enables the variable operation with different motors. The number of parameter sets can be encoded via the digital inputs or alternatively via the provided data interfaces.

Gap Eliminator / Load Indicator – The load indicator is a standard function that is implemented
in all devices of series SD2x. The function is used to monitor the status of the active current of spindles. If a preset
motor workload is exceeded, the function generates a message. In contrast to acoustic emission sensors, this function
evaluates the actual active current of the motor. This is why a very high precision is possible when detecting the
load changes of the motor. A load created by e.g. a touch between tool and work piece causes a significant rise in
the motor current. Such a load is detected by means of the load indicator. This makes additional external
components obsolete.

The load indicator can be used:
- as an indicator for tool breakage
- as a main system in dressing processes
- for a detection with micrometer precision when the tool touches the work piece (gap / touch)
- as an indicator for a necessary tool change due to abrasive wear
- as an indicator for a necessary feed rate reduction (productivity increase by reducing the air-cutting time)
- for a fully automatic adjustment
- as a substitute for acoustic sensor technologies (acoustic emission)