UNIFREM Frequency Converters
UNIFREM frequency converters (variable-frequency drives) are the flagship product of VONSCH.
They are versatile, modern frequency converters built from the best elements, with rich software features, available in many variants.
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Characteristics and advantages of UNIFREM
High fault tolerance
UNIFREM has integrated protections against overvoltage, undervoltage, overcurrent, ground fault, short circuit between phases and thermal overheating. The system reacts to input or output phase failures and the calculation of the thermal integral of the motor prevents overheating, thus increasing the long-term service life of the equipment.
Minimal impact on the power grid
Three-phase commutating input chokes minimize the extraction of higher harmonic currents, while standard suppression filters ensure minimal interference to the power grid according to EN 61800-3 and EN 61000-6-4.
Minimal losses – “lossless” inverter
The use of state-of-the-art solid-state power elements virtually eliminates losses in the inverter, minimizing energy dissipation while reducing interference in and around the power system.
Minimised dimensions
The optimization of the power-designed heat sinks and the strategic placement of the power elements allows to achieve significantly reduced device dimensions without compromising on performance.
High reliability
A new generation of power capacitors with increased temperature range and extended lifetime, together with fans equipped with quality bearings, guarantee long-term reliability and quiet operation of the inverter.
Advanced vector control
UNIFREM enables open and closed vector control of asynchronous and synchronous motors with high precision and dynamics. Automatic online parameter adaptation, for example identifying changes in winding resistance or inductance saturation, ensures optimal performance even under changing conditions.
Speed, torque and position control
The device is designed for the most demanding applications where the required speed, torque and position must be precisely maintained. With a high sampling period of 200 µs, it also enables extremely precise position control.
Precise scalar control
Scalar control with U/f curve and slip compensation provides very precise adherence to the desired speed, with control quality comparable to simpler vector control – ideal for applications with smaller requirements.
Rich software equipment
Interactive display listings and a clear parameter structure simplify setup and monitoring of the device. Parameter access is possible in several ways and is supported by different levels of user authority. Integrated logic blocks (PLC) and independent communication lines (RS485, USB, CAN) ensure uniform and flexible operation.
Comprehensive features and flexible optimisation
The device offers kinetic backup for short-term power failures, a fly start on a revved motor and three different braking modes. A versatile PID controller, a fully configurable input and output system, dedicated crane software and the ability to switch between four sets of parameters with user macros allow optimization of power input or maximization of power output to suit specific requirements.
Wide communication compatibility
Support for CANopen, MODBUS and PROFIBUS communication protocols ensures seamless integration with other systems and devices, greatly expanding the inverter’s application possibilities.
Complete history of events and faults
The configurable system logs up to 1,000 fault, warning and event records, greatly facilitating equipment diagnostics and maintenance.
VONSCH Drive Studio
The innovative VONSCH Drive Studio software allows setting up, diagnostics and archiving of data to a PC. It allows firmware upload, parameter reading and archiving, processing of diagnostic data from the “black box” and display of graphical waveforms, thus simplifying the operation and maintenance of the inverter.
VF version for high frequency or special motors up to 3000Hz
All frequency converters (UNIFREM 400M and above) are also available in VF version for high frequency or special motors up to 3000Hz. UNIFREM VFs allow independent adjustment of output voltage and frequency.
