The salient features & specification for SMPS based power plants are given in the table below. The figure of high frequency switched mode power supply is shown below:
Salient Features of SMPS System:
- Smaller in size, 70 to 80 % reduction in size as compared to the thyristor controlled power plant.
- Lesser in weight, 70 to 80 % reduction in weight as compared to the thyristor controlled power plant.
- Modular concept, easy to maintain, easy to install and easy to expand the capacity.
- Higher in efficiency (above 90 %).
- Improved power factor (near to unity).
- Controlled harmonic distortion.
- Limited inrush current. No need to install higher capacity EA set.
- Accepts wide input voltage variation.
Specification for SMPS Based Power Plant: (GR NO. G SMP-01- 03 MARCH 97).
Single Phase: 6.25 A, 12.5 A, 25 A & 50 A.
Three Phase: 50 A, 100 A & 200 A.
Rural System: For small loads.
Urban System: For large loads.
- VRLA Battery.
- Lead Acid battery.
- Dry Heat upto 55 °C.
- Cold temp upto -5 °C.
- Humidity upto 95 % RH at 35 °C.
Natural cooling: For 6.25 A, 12.5 A & 25 A modules.
Forced cooling: For 50 A, 100 A & 200 A modules.
- 1 ϕ, 230 V (150 to 275V).
- 3 ϕ 400 V (320 to 480V).
- 1 ϕ, 230V (150 to 275V).
- 3 ϕ, 400V (340 to 440V).
Frequency: 50 Hz (48 to 52 Hz).
Power Factor: Between 0.9 lag to 0.98 lead.
- 80 to 85 % for 1 ϕ units.
- 85 to 90 % for 3 ϕ units.
Voltage Distortion: within 10 %.
Current Distortion: within 20 % for loads between 50 to 100 %.
EMI/EMC: As per GR No. G/EMI-01/01 APR 90.
Lead Acid Battery VRLA Battery Auto Float Voltage: 52.8 V 54 V. Auto Charge Voltage: 56.4 V 55.2 V. Extended Charge: 65.0 V N.A.
Regulation: ±1 %.
Current limiting: 50 to 100 % adjustable.
Psophometric Noise: 2 mV / 4 mV with/without Battery.
Peak to peak ripple: 300 mV maximum.
Protection: DC overvoltage fuse / CB in output path for overload/Short circuit.
Soft Start (Switch ON):
- Build up time less than 10 s.
- Overshoot less than 5 % per 20 ms.
Load Sharing: Within ±10 % at 50 to 100 % load.
Rural Sustem Urban System Height (max.) 1500 mm 2200 mm Depth (max.) 600 mm 600 mm Width (max) 750 mm 750 mm
Floor loadind: Less than 975 kg/m².
Functional (Module / System level):
- Mains available.
- FR/FC on Auto Float.
- FR/FC on Auto Charge.
Alarm (Module level):
- DCOV/DCUV/Output Fail
- FR/FC Overload.
- Fan Fail (Due to any reason).
Alarm (System level):
- Load Voltage High/Low.
- FR/FC fail.
- Mains out of range.
- System overload.
- Mains ON battery discharge.
- Fan fail (at rack level).
- Temp Compensation Fail.
- Battery Fail/Isolated.
Health monitoring: auto Float/Charge operation depends upon battery condition.
Charging Current: Battery current limiting in Float / Charge mode of operation.
Isolation: Battery cut-off at 44.4 V for Rural / Unattended stations.