The power factor of the electrical grid is greater than 0.95 throughout the motor's operating range, without an additional harmonic filter or compensation capacitor. The integrated device architecture provides power grid harmonic distortion data for current and voltage (THD I/V and TDD), in accordance with IEEE 519, IEC 61800-3, and G5/4-1. The device meets the limits specified in these standards, even in its basic configuration.
The inverter's efficiency, including the transformer, exceeds 95% across the entire motor speed range and surpasses 96% at load levels above 40%. The multi-level power transformer's charging circuit ensures core magnetization without inrush currents and smooth charging of the DC link capacitors for the converter stage.
The power transformer adapts the mains voltage to the transformer's output voltage and reduces the common-mode voltage in the motor windings. It also reduces common-mode current flow through the motor bearings, maximizing their lifespan. Fiber optic interfaces between the frequency converter's central processing unit and the power stage for IGBT and temperature control, as well as voltage and current feedback, are implemented to enhance noise immunity and provide effective isolation between the control and power sections. The power stages (H-bridges) are constructed with plastic film capacitors, semiconductor fuses, and an automatic converter bypass function, contributing to higher system availability in the event of a fault. The virtually sinusoidal output voltage and current minimize power dissipation, vibration, and torque pulsations in the motor.
For greater system reliability and availability, the MVW3000 is equipped with devices that protect the motor against overloads, overheating, and rotor lockup. In addition, the temperatures of the power stage and transformer are monitored.
Measuring 3,900 mm (width) x 2,210 mm (height) x 1,100 mm (depth), the variable frequency drive also boasts a compact design. Furthermore, it can be equipped with all commonly used communication protocols, including Modbus, Profibus, DeviceNet, and Ethernet.
