Static Frequency Converters
The Megatherm Static converters are the result of development from experience in solving Induction Heating & Melting problems for the Industries. Design have been re-engineered to achieve easy maintenance, minimum breakdown and operate continuous operation at full power under all adverse site conditions. A high availability rate and higher operating efficiency are the salient features. Megatherm converters are equipped with proven reliable parallel resonant type Inverters for the entire frequency range.
Available Models
Melting Series I (Foundry)
| Capacity
(KG) |
50 |
75 |
100 |
150 |
200 |
300 |
500 |
750 |
1000 |
| Rated Power
Output (KW) |
50 |
100 |
100 |
125 |
150 |
200 |
350 |
450 |
550 |
| Power Variation |
‹—
5% to 100% —› |
| Max
Frequency (HZ) |
3000 |
3000 |
3000 |
3000 |
3000 |
1000 |
1000 |
1000 |
1000 |
| Input Supply
Voltage (Volts) |
415 |
415 |
415 |
415 |
415 |
415 |
415 |
415 |
660 |
| Input (KVA) |
55 |
82 |
110 |
135 |
165 |
220 |
380 |
500 |
610 |
Melting Series II (Foundry)
| Capacity
(KG) |
1500 |
2000 |
3000 |
3500 |
4000 |
5000 |
8000 |
10000 |
12000 |
15000 |
| Rated
Power Output (KW) |
1000 |
1250 |
1500 |
1600 |
1800 |
2500 |
3000 |
4500 |
5500 |
6500 |
| Power
Variation |
‹—
5% to 100% —› |
| Max
Frequency (HZ) |
500 |
500 |
500 |
500 |
500 |
500 |
500 |
400 |
300 |
300 |
| Input
Supply Voltage (Volts) |
660 |
850 |
850 |
1250 |
2x850 |
2x850 |
2x850 |
2x850 |
2x850 |
2x850 |
| Input
(KVA) |
1080 |
1360 |
1630 |
1740 |
1960 |
2720 |
3260 |
4900 |
6000 |
7100 |
Heating Series III
| Rated
Power Output (KW) |
25 |
50 |
75 |
100 |
150 |
200 |
250 |
300 |
| Power
Variation |
‹—
5% to 100% —› |
| Max
Frequency (KHZ) |
50 |
50 |
25 |
10 |
10 |
10 / 3 |
10 /
3 |
10 / 3 |
| Input
Supply Voltage (Volts) |
‹—
3Ph 415V 50Hz —› |
| Input
(KVA) |
35 |
70 |
107 |
142 |
210 |
285 |
350 |
425 |
Technical Characteristics
Megatherm's Static Frequency Converters mainly consist of
Rectifier, DC link and Inverter. The rectifier consist of one or more fully controlled three phase bridges employing
the latest semi-conductor technology and digitally controlled special phase locked loop synchronization
enabling power source to operate with mains as well as Gas/Diesel generator sets easily. This design allow
infinitely variable adjustment of converter output between 5% to 100% of its rated power capacity. The DC link circuit
consists essentially of water cooled reactors with special type of winding. The DC link circuit smoothens the current
from rectifier which is fed to the inverter. Moreover, the smoothing choke prevents an excess rise of current in the
DC link circuit in the event of a short circuit on the load. On each switch off, the flow pattern in the rectifier
is reversed, so that magnetic energy stored mainly in the DC link circuit is feed-back into the mains. High speed
semi-conductor fuses are fitted to protect the power thyristors.
Inverter consists of one fully controlled single phase bridge employing the latest high speed distributed gate
Thyristor or Insulated Gate Bipolar Transistor (IGBT). By alternate switching on/off of the inverter device, an
alternating current is produced in a load circuit. The inverter electronics control ensures that inverter runs at
the frequency determined by the natural resonance created by the load.
Power conversion efficiency of Megatherm panels is very high. At 500Hz. frequency the efficiency is 97% and between
10 Hz. to 50 KHz. is 91%. The main advantage is that efficiency together with instant readiness for operation
and reliable starting offer excellent possibility of controlled energy savings on different type of parallel
compensated resonant load circuits. |
