Third generation of frequency converters

KW Aufzugstechnik has presented a new frequency converter at interlift in the form of the Goliath 921.

Following three years of development, the third generation of frequency converters is about to see its launch with the Goliath 921. It is a further development of the current Goliath 90 series. Its compact design permits positioning of the frequency converter internally in the switch cabinet as well as externally in the lift shaft. Thanks to standardised cable sets, easy installation via plug & play is possible, according to the company.

Advances in power electronics mean the latest generation of the highly efficient IPM modules can be used. They have only slight switching losses and therefore produce minimal waste heat.

The modern 32-bit microcontrollers with floating point units permit control processes with high precision and speed in the microsecond range. This facilitated extraordinary travel comfort, the manufacturer emphasised. Together with pulse multiplication in the speedometer analysis, ten million pulses per motor revolution are generated, resulting in precise position control and as a result in imperceptible start-up, according to KW Aufzugstechnik.

"Noiseless and wear-free"

Photo: © KW Aufzugstechnik

Like the predecessor converters, it operates at a 16 kHz clock rate. In combination with the contactorless operation without internal power relays / power contactors, operation is noiseless and wear-free, the company stated. A secure interface for the optional attachment of a contactorless brake device or conventional brake for three brake circuits is integrated.

Almost all drives on the market can be operated with the Goliath 921. For this purpose, all common encoder interfaces, such as TTL, HTL, Sin/Cos, EnDat, Hiperface, BissC, SS and optionally the resolver interface are available. For the controller, the familiar bus protocols such as KW Liftbus, DCP and CANopen-Lift are implemented but integration of the converter in an existing controller can also be realised by a parallel control with 13 freely assignable 24V IO interfaces.

User access is possible optionally via the bus protocol as well as via Bluetooth and WLAN interfaces, which provide a GUI via the web interface. In view of the coming EN ISO 8100-1 standard, the Goliath 921 not only provides for brake ventilation and wear monitoring but also activation of the third brake element.

More information: kw-aufzugstechnik.de