Catalog

Description

0.75 – 500 kW

Specifications:

The inverter of MFC710/AcR series is designed for control of asynchronous motors with a rated voltage of 400 V. We also offer designs for voltages of 500 V and 690 V, as well as other customized specifications upon individual agreement. This drive allows for the return of energy into the grid (four-quadrant grid rectifier).

MFC710/AcR was developed by incorporating the AcR (Active Rectifier) reverse rectifier module into the MFC710 frequency inverter, replacing the regular input circuit. This eliminates issues related to the usage of diode rectifiers in drive systems, namely:

– current and voltage distortion in the grid due to the nonlinear nature of the load;

– unidirectional power flow.

The following diagrams show the block schemes of both types of the converters.

Block scheme of the traditional MFC710-type system:

Block scheme of MFC710/AcR-type system:

Using MFC710/AcR-type inverter, we obtain:

• Correction of PFC power factor, reduction of current distortion factor (THDi), and voltage distortion factor (THDu). AcR module allows for a sinusoidal current waveform, eliminating the negative effects of higher harmonics integrated into the grid while using conventional power supply systems.
• Bidirectional power flow, four-quadrant operation. In conversion drives, it commonly occurs that the energy stored in the load is to be reversed to the source or dissipated as heat in a braking resistor. In case this process is intensive or occurs frequently, the usage of an additional braking resistor may be economically inefficient or impossible. AcR module ensures a bidirectional energy flow, which facilitates the transfer of the stored energy to the grid for recycling. This solution is justified not only from the energy balance perspective, but also in terms of operational costs. Apart from that, the module is used in centrifuge drives, cranes, and energy recovery systems from renewable sources.
• DC link voltage stabilization. AcR module is a three-phase boost AC/DC converter. This means that the voltage in the DC link of the inverter can be higher than the voltage in the grid. By using AcR module in a frequency inverter, it is possible to obtain an output voltage higher than the supply voltage (for example, with an input voltage of 400 V AC at 50 Hz, the output voltage can be 0-500 V AC at 0-400 Hz).

MFC710AcR 200 kW 400 V

Technical Specifications:

• Grid-side voltage: 3×400 V, 3×500 V, or 3×690 V, 45–66 Hz; other voltage levels are available upon request
• Electrical machine-side voltage: 3 x 0–400 V, 3 x 0–500 V, or 3 x 0–690 V
• Reversible rectifier (with energy return to the grid)
• Control:

– scalar U/f (linear/quadratic);

– vector (sensor/sensorless).

• Detachable alarm and control panel with an LCD display
• Built-in PLC
• Built-in pump or fan block controller
• Built-in PID controller
• RS232/RS485 built-in communication module (MODBUS)
• Option of control over operation and parameter settings via communication channel
• Programmable constant speeds
• Motor potentiometer function
• Option of direct connection of the incremental encoder (5V, linear transmitter)
• Elimination of programmable resonance frequency bands
• Specific shapes and slopes of the speed setting  characteristics (linear, “S” curve)

Programmable control structure:

– switchable control options (A, B);

– speed setting (control panel, analog input, PID controller, motor potentiometer, PLC block);

– start/stop (control panel, digital inputs, PLC block);

– programmable digital inputs: start/stop, direction, operation lock, external fault, fault rectification;

– programmable digital outputs (3 relays and 1 open collector): standby, operating, fault, warning, radiator temperature exceeded, set or maximum speed reached, current limit reached, PLC block output;

– programmable analog outputs: frequency, rotation speed, output current, output voltage, load level, PLC block output.

• Operational time measuring
• Real-time clock (optional)
• Locking and diagnostic system
• Keyboard protection with access codes system
• Saving parameters for 4 motors
• Factory-preset parameter sets

MFC710/AcR frequency converters do not include a built-in braking transistor by default, which prevents the connection of an additional braking resistor.

If you need the drive equipped with a braking transistor (necessary to connect an additional braking resistor), please, inform us while ordering. This is essential, as the braking transistor is installed at the stage of production and cannot be added later.