Purpose of medium-voltage variable frequency drive EK-AV6
The variable frequency drive (VFD) EK-AV6-XX-XF-IX, manufactured by Energocomplekt JSC, is designed to ensure effective speed control of medium-voltage AC motors with a stator voltage of 3, 6, 10 kV. the VFD is based on power IGBT-transistors with multi-level PWM. The EK-AV6-XX-XF-IX does not require the installation of additional equipment to reduce the negative effects of energy conversion.
The EK-AV6-XX-XF-IX is fully digitally controlled, can be used in automated manufacturing, controlled and monitored by a higher-level control system.
Frequency converter EK-AV6-2.0-AF-I6, 2000 kW, 6 kV.
The EK-AV6-XX-XF-IX has a powerful microprocessor control system combined with high-speed power modules, which demonstrates the following advantages:
- smooth speed control over a wide range;
- smooth start and smooth stop of the engine;
- high accuracy of maintaining the technological parameter;
- ease of reconfiguration of parameters for specific operating conditions;
- significant reduction of engine noise and vibration;
- the possibility of working under the control of the upper level ACSMS using the protocols ModBusRTU, Profibus DP.
When using frequency converters EK-AV6-XX-XF-IX:
- there is no significant harmonic interference in the supply network;
- no need for power filters in the chain of VFD-AD;
- the length of cables from the VFD to the engine can reach 2 km;
- the power factor is not less than 0.95;
- possible dynamic braking of the engine (direct current supply to the stator) and run-out;
- does not require the selection of special engines with an increased class of insulation, engine heating does not go beyond the usual;
- it is possible to restore the efficiency of the VFD in a short time without using a special tool (cell replacement is possible in less than 30 minutes).
Functional scheme of the power part of the cell.
Working principle
To improve the quality of the output voltage, the EK-AV6 panel contains a number of pulse-width converters (cells) of low power. Each power cell has its own three-phase rectifier attached to the secondary winding of the input transformer with a voltage of 690 V. The 6 kV VFD uses 15 cells of 690 V, connected by 5 in phase sequentially, the phases are connected into a star.
Each cell is designed for full output current, but operates only at 1/5 of the output voltage. The 3 kV and 10 kV frequency converters contain 3 and 8 cells in phase, respectively.
Composition
Structurally, the EK-AV6-XX-XF-IX consists of separate cabinets, each of which includes five power cells, air cooling forced or water. The control system is installed in a separate control cabinet and is connected to the cells via a fiber-optic channel.
Structural diagram of the frequency converter series EK-AV6.
The EK-AV6-XX-XF-IX has a fully modular structure. The damaged module can be easily and quickly replaced. The failed cell is automatically turned off without operator intervention, while the power output of the drive drops by 10% (for the VFD by 6 kV).
The company performs supervision, equipment adjustment, warranty and post-warranty service, training of service personnel, technical advice on the choice of equipment. Equipment delivery is carried out within 6 months from the date of conclusion of the contract and prepayment.