Variable Frequency Drive

Variable Frequency Drive

Medium Voltage (MV) Variable Frequency Drives (VFD) ElectroDrives ED27 are designed for automatic control of a wide range of industrial systems with squirrel cage induction motors (SCIM), synchronous motors (with or without an external exciting system) and permanent magnet motors.

ElectroDrives’ VFDs have extensive motor control functionality and cover a large power range to operate with mills, crushers, conveyors, pumps, fans, compressors, extruders, mixers, etc. They offer wide sets of functions and unique algorithms for high-quality control of motors. The implementation of ED27 VFD provides increased reliability of equipment operation, productivity, and energy savings. Innovative technical solutions in the field of transformer design, cooling systems and intelligent algorithms development guarantee a non-stop operation of equipment minimizing the costs.

The ElectroDrives VFD is an adaptive solution compatible with any environmental conditions and the best option that ensures a long-term operation. It is represented by three lines, each of which was created for different climatic conditions: from comfortable conditions of electrical rooms to extreme conditions of hot deserts and Arctic colds, for coastal climates or installation in metallurgical plants:

  • ED27 series for indoor installation in an IP31 (NEMA2) or IP42 (optional) enclosure with an operating temperature of 0ºC up to 50ºC.

  • ED32 series for outdoor installation in an IP65 (NEMA4) enclosure with dual independent air-cooled circuits with operating temperatures of -30ºC up to +60ºC.

  • ED37 series is the integrated containerized solution for outdoor installation in an IP43 e‑house with operating temperatures of up to -60ºC to +50ºC.

Robust design with multiple possibilities. ElectroDrives has gained its reputation for the robustness of their medium voltage equipment within the last 25 years which have been recognized by the most demanding customers in critical applications. Developing redundant solutions with flexible applications at an affordable price has enabled the operation of different systems in variable speed mode.

Air cooling system. When dealing with medium voltage is very important to understand the robustness and reliability that the air-cooling system provides to the process. Water-cooling systems are more compact in size, but they increase the installation time and cost and could represent a risk in case of leakage. ElectroDrives ED27 cooling is forced-air type. The cooling system is based on exhaust fans mounted on the roof.

The fan speed is controlled by software and is optimized depending on the temperature of the transformer windings and power cells. Air filters are used to prevent dust and other impurities from getting inside the cabinets. Filter mats can be replaced without stopping and without opening the power sections of the VFD.

Simple integration. Direct connection to the mains and motor is achieved by ElectroDrives ED27 VFD structure itself with an input multi-winding phase-shifting transformer and series connection of power cells from the motor supply.

Due to the high voltage operation, the MV VFD keeps the input and output currents very low, therefore a much smaller cable section is required.

Versatile operation of any motor. ElectroDrives ED27 operates squirrel cage induction motors, synchronous motors as well as permanent magnet motors. Due to the low overvoltage obtained with our unique technology, ElectroDrives ED27 is capable to operate with existing old motors with standard insulation, as well as with the new motors designed for VFD applications, with reinforced insulation. All this is obtained without any additional output filters.
The multilevel pulse width modulation (PWM) provides a pure sine waveform in the output current, with a very low harmonics distortion current (THDi ≤ 2%) and voltage (THDu ≤ 5%).

Multi-cell topology and power quality. ElectroDrives ED27 topology with a multiple-winding phase-shifting transformer, with a multi-pulse rectifier (18-pulse up to 54-pulse rectifier), reduces the harmonics content dramatically and increases the power factor at the input, making unnecessary any additional filter or capacitor bank in the plant. Additionally, the multi-cell technology simplifies the construction of the drive making maintenance extremely easy.

Motor start station. ElectroDrives provides a wide range of algorithms and software suited for each application, enabling to connect up to nine motors to one ED27 VFD, including all necessary MV switchgear required to do so.

Synchronous transfer of the motor from the drive to the mains and back is the basis for reliable process control. For example, it is possible to soft-start one or several ball mills smoothly and, once that they are connected directly to the mains, to have speed control in a SAG mill with the same ED27 VFD.

Small footprint. ElectroDrives approach to the design of compact format transformers, power elements and cooling systems, allows optimization of the drive overall dimensions. Moreover, the one-sided maintenance and installation concept of the ED27 VFD line enables to save even more space.

Voltage sags protection. Our ElectroDrives ED27 is specially designed to operate during voltage sags and dips in the mains. Additionally, the VFD is rated to operate continuously at a gird voltage as low as 85% without derating. This provides uninterruptible process operation at the most adverse grid conditions.

Easy setup and monitoring. ElectroDrives ED27 VFD is equipped with a Wi-Fi adapter. It enables easy commissioning via a cell phone or tablet using the ED27 wizard application in few clicks. The wizard allows performing a step-by-step drive setup, checking operation waveforms and building a report of the operating performance.

Redundancy options

Having ElectroDrives more than 25 years of experience in especially critical processes, the ED27 VFD provides several possibilies to prevent any shutdown or unavailability of the equipment:

  • The power cells bypass option enables the continuous operation of the motor in case of a failure of any power cell. This is possible to combine with additional power cells that increase the overvoltage capability of the VFD.

  • Redundant fans with the use of air valves guarantee that in case a fan fails, the cooling system is able to provide the necessary flow without stopping and without limiting the load in the motor.
  • Redundant VFD or bypass allows in extreme demands of redundancy and backup to operate the motor independently with one ED27 VFD or other, or even to start the motor in DOL.