FC2

Frequency Converter FC2 – The Drive for High-Speed Applications

FC2 is conceived for parallel operation of several asynchronous spindles with speeds up to 500,000 rpm. The required interfaces for temperature sensors and motor encoders are already integrated. Thus FC2 can operate up to 12 spindles and monitor the corresponding sensors whereas the proper control does not require any motor encoder. The PAM mode (Pulse Amplitude Modulation) allows operating the spindles without additional motor chokes. The above described features of FC2 reduce the system costs. The device is connected to the control via an analog reference speed value, the serial interface (RS232) or via SERVOLINK 4. The wide-range power input and the integrated power supply of FC2 allow its autarkic use in the machine so that the voltage of the spindles is independent of the voltage of the positioning drives.

Multi-Spindle Operation without Sensor

The control without sensor allows parallel operation of several asynchronous motors. Since motor encoders are not required spindle costs and wiring work are reduced. The reliability of the machine increases as broken cables and electromagnetic interferences in encoder lines have no influence anymore.

Speed-Dependant Switching between Modulation Modes

In order to provide the maximum torque for small speed values and to keep power losses in the spindle as small as possible the modulation mode is switched in dependance on the speed. This allows optimum operation characteristics of the spindles over the complete speed range.

Slip Compensation and Load Compensation

The slip compensation is able to compensate for the system inherent spindle slip. For this purpose the output frequency and the output voltage is increased by the frequency converter correspondingly to the operating point of the spindle in order to reach the reference speed in spite of the slip of asynchronous motors.

The load compensation supplies the required current in dependance on the spindle load. This function ensures that current only flows, if it can be converted into a torque. This leads to an important temperature reduction during no-load operation, even though the maximum torque is provided.

Safety Integrated

The safety category 4 according to EN 954-1 can be reached by the integrated restart lock. As external protective circuits are not necessary, system costs are reduced. The requirements according to SIL 3 of EN 61508 are met.