A wide range of applications
In recent years, high energy consumption has constrained economic growth very badly with the enhancement of industrial GDP, therefore, the Government has invested much money to support energy saving and consumption. Medium voltage variable frequency drive technology has been widely used for speed regulation, energy saving, soil startup and intelligent control of the medium voltage motors in industries such as thermal power plant, petroleum, chemicals, mining and metallurgy. Borna Electronics Co. has manufactured Medium iVoltage Variable Frequency Drive which is branded by BORNA-MegaDrive, based on near 30 years rich experiences in power electronics and relay protection. BORNA-Mega Drive can be widely applied to the following industries:
Power Generation: Induced draft fan, forced draft fan, condensate pump, feed pump, primary air fan, secondary air fan, booster fan, circulating pump, mill fan, slurry pump etc.
The petroleum and gas industry: compressors, draught fans, transfer pumps etc.
The metallurgy: blast furnace blowers, dust blowers, water pumps etc.
The large water transport project: water intake pumps, water supply pumps, pressure pumps etc.
Coalmine: belt conveyors, exhaust fans, etc.
Cement: kiln head fans, kiln inlet fans, circulating fans, high-temperature fans, raw material grinding machines, etc.
Others: Loads such as fans pumps and compressors in pharmaceutical, paper making and wind tunnel test.
- BORNA-MegaDrive is a voltage source inverter which can realize a very smooth speed regula- tion for medium voltage motors. It makes typical motors into intelligent ones
- BORNA-MegaDrive output voltage contains few harmonics which causes the motor not to generate extra heat and noise.
- Low harmonics and high power factor input, the typical value for power factor is 0.95 for loads more than %20, and there is no need for power factor correction.
- Modularized design of power units, interchangeable and easy to produce and repair, the capability of finding faults based on advanced diagnostic procedures in CPU
- BORNA-MegaDrive can operate even under the pppcondition of fault occurrence for some parts of power units using bypass function.
- Applicable to all kinds of power grids and suitable for typical medium voltage motor.
- Colorful touch screen, easy to operate and maintenance.
- Able to realize remote control, DCS operation and communications with Host, and support all kinds of communication interfaces such as CAN Profibus, Modbus, RS232, RS485 etc.
- Using the most advanced components, master control chip adopted TI’s DSP F28335 and ALTERA’S FPGA of EP3C to realize powerful processing capacity. Sampling adopted AD’s AD7606 with 16 bit to ensure control accuracy
- The switchgear can satisfy safety requirements, and the pressure-relief channel of high voltage switch can ensure safe use of operators.
- The ability of working under 2 different control modes: ooothe V/f and vector control modes
- BORNA-Mega Drive has a high amount of MTBF (Mean Time Between Failures) index about 100000 hours and low amount of MTTR (Mean Time To Repair) index about 10 minutes.
Configuration of BORNA-MegaDrive
BORNA-MegaDrive is a medium voltage multilevel convertor constructed by the cascade connection of single phase H-bridge inverters in series to achieve the required medium voltage output. Each single phase inverter receives input DC power from its own isolated 3-phase rectifier, itself fed with a separate transformer secondary. Each rectifier and associated inverter is assembled into an identical Power Module. BORNA-Mega Drive consists of phase shifting transformer cabinet, power unit cabinet, control cabinet and synchronization cabinet (optional).
This cabinet is used for installation of Phase-shift transformer with grade H insulation which is a dry type transformer with functions of temperature display and over-heat protection. The secondary multi-winding output pro- vides phase-shift power supply to power units. This can greatly improve the current waveform on grid side and reduce the harmonic interferences.
Grid-Connected Synchronous witching System
It is composed of the switching cabinet, a reactor cabinet and a synchronous-controller cabinet. The whole switching system is controlled synchronously by a sync-controller to ensure that the motor can be switched to the grid system smoothly from the VFD when its output voltage keep the phase-sequence and voltage value same as grid system.
Control Cabinet This Cabinet is used for installation of low voltage control components such as PLC,UPS, Electric siren, DC 24V power supply, Control Power Source Switch, Wiring Terminals, Touch Screen, Operation Button etc. Furthermore, the fiber optic communication, which makes completed elec- tric isolation between the control section and the high voltage section is used in order to ensure the safety and reliability of system.
The power cell is a AC-DC structure with a 1-phase output which is fed by a 3-phase input. AC voltage from the transformer secondary winding pass through the power cells input fuses to 3-phase diode rectifier, and with capacitance filter to become smooth DC voltage. Then the DC voltage feeds a single phase H-bridge circuit with 4 IGBT and becomes single-phase AC output with variable voltage and frequency. Each power cell has the same mechanical and electrical structure, and they can be exchanged with an- other one.