Harmonics supprenssion and power factor/comprehensive efficiency improving
Energy saving by SC7
SC7 series is harmonics suppression converter to conect inverter drive equipment.
SC7 control input voltage and input current to same phase (power factor=1) for harmonics suppression.
Therefore, to use this SC7 will be energy saving by harmonics suppression and power factor/comprehensive efficiency.
Outline of comprehensive efficiency improving
Power supply equipment efficiency |
Improving by power factor=1 control. |
Capacity of breaker
Cable size |
Reducing capacity of wiring apparatus by decreasing motor current and input current. |
Inverter efficiency |
Improving by inverter's inside loss; Rectifier loss is nothing. |
Motor driving voltage |
Keep the motor driving voltage to high level without voltgae drop as rector. |
Motor efficiency |
Improving by decreasing motor current for high motor driving voltage. |
- Comparison of needed input capacity:
Inverter only:
Input Capacity = (1.732*Vout*Iout)/(eff1 * cosX)
Connected SC7:
Input Capacity = (1.732*Vout*Iout)/eff2
Vout: Inverter's output voltage
Iout: Inverter's output current
eff1: Inverter's efficiency
eff2: Inverter and SC7 efficiency
cosX: Inverter's input power factor
Inverter's input power factor:
Reactor installing: about 0.8
nothing: 0.4~0.6
Note:
Interter's input power factor depends on capacity of power supply and impedance of wiring.
- In case of driving 160kW motor (440V-250A)
Condition |
Inverter/Converter efficiency |
Total power factor |
Necessary input Capacity |
Inverter with DC choke |
0.96 |
0.8 |
248.1 kVA |
Inverter with SC7 |
0.98 x 0.98 = 0.96 |
1 |
198.5 kVA |
Condition |
Input current |
Cable size |
MCCB flame |
Selected transformer capacity |
Inverter with DC choke |
253 A |
100 mm2 |
400 AF |
300 kVA |
Inverter with SC7 |
194 A |
60 mm2 |
300 AF |
200 kVA |