Static Frequency Converters are used to feed loads that need AC mains at a different fixed frequency than the available one. By means of an intermediate turn into DC, the unit is able to deliver the requested AC power at the specific frequency.
So this system includes 2 sub-systems: - rectifier: turns AC input mains into DC - inverter: turns DC mains into the output AC one, at the necessary frequency
It is possible to add a set of batteries in order to provide the system with a certain autonomy in case of a input mains failure.
UNIT DESIGN
Excellent dynamic behaviour unit, with IGBT transistors. One microprocessor control manages the system considering the received signals and orders, and informs the user about its status. Control functions:
- historic: 250 last alarms displayed, with date and time - automatic control: programmable start-up and shut down - diagnosis: unit status is displayed and transmitted - measures: •Vef and Ief of all phases •active, apparent and reactive powers •internal temperatures •efficiency •input and output power factor and frequency - test: automatic, local/remote, periodical and programmable - digital adjust: adjustable parameters by keyboard - configurable: adjustable system basic functions - help: it provides help for the keyboard use
MAIN FEATURES
• high input power factor, ≥ 0,95 • perfect sine-wave output signal, digitally synthesised • high frequency and output voltage stability • high efficiency, simplicity and reliability • excellent behaviour with non linear unbalanced loads • digital multiprocessor control, PWM modulation • display, keyboard, leds, and serial I/O channels interface • galvanic insulation transformer incorporated • parallel operation with other units, as an option • it could include a 28 VDC auxiliary power supply, up to 1000 A
SPECIFICATIONS (generic, to detail for each case)
Input Three-phase 220 / 380 / 400 VAC, +15%, -10% Frequency 50 / 60 Hz, ± 5% Power factor up to 0.9
Output From 5 to 2500 kVA Frequency 50 / 60 / 400 Hz, ± 0,1 % Single-phase 220 VAC, ± 1 % Three-phase 220 / 380 / 400 VAC, ± 1 % Voltage adjustment ± 5% Vn Admissible cos φ 0.6 capacitive / 0.4 inductive First harmonic 3% Max. global THD dist. with linear load < 3 % no linear load < 5 % Dynamic response ± 5 % Response time 30 ms Crest factor 3 Efficiency 84 – 96 %, according to power
Options Pb or NiCd batteries 6 or 12 pulse Anti-harmonics filter BPL stabiliser transformer Auxiliary pwr. sup. 28VDC / 40 to 1000 A Redundant Parallel operation with other units Antiseismic, Class 1E Output distribution switchboards Control cabinets Adaptable to different standards (MIL, UL, ...) Container mounted Design Metallic self-stable cabinet Protection grade IP20 to IP54 Colour RAL 7032 (typical)
All the above characteristics could be modified under demand |