In one of our industrial areas we have replaced HPSV (High-Pressure Sodium Vapour) light fittings with LED light fittings. We are also using APFC (Automatic Power Factor Control) for improving the power factor. The power factor was around 0.8 with APFC was used along with HPSV light fittings.
The LED lighting system is getting damaged when APFC is in the circuit. On investigation of the failure of LED lights, it was found out that there is a surge in the Voltage in LT lines. The voltage is not expected to exceed 250 V in the LT lines. Thus, APFC had to be taken-off as it was causing high voltage in the LT line. However, removing APFC reduces the power factor and it is now around 0.68 to 0.70. LED lights are not getting damaged when APFC is removed from the circuit.
Note: HPSV light fittings had inbuilt surge voltage protection and hence they were not getting damaged.
APFC should be used as it improves power factor and helps receive subsidy from the local electricity board.
APFC unit has 16-stage capacitor bank. The technical details are provided in Table 1.
Table 1: APFC Details
|Number of stages||16|
|Total Capacity of APFC||225 KVAR|
|Number of capacitors||Total 8 nos (50 KVAR – 3 nos., 25 KVAR – 02 nos., 10 KVAR – 02 nos., 05 KVAR – 1 no)|
We are looking for solutions that will enable the use of APFC without causing voltage surge and subsequently damaging the LED lights.
System should be
- Easy to manage.
- Easily integrated into existing operations.
Details relating to LED ratings, Distribution Transformer capacity and its tap positions are as follows.
- LED ratings: LED light fittings are from 100 to 350 Watt and voltage bandwidth is 130 – 245 V.
- DT (Distribution Transformer) capacity & rating: 200 KVA DT. (3 Ph, 3300 / 433 V, 50 Hz, Dyn11, H.V. Amp. – 34.88 & L.V. Amp. – 266.66, ONAN)
- DT Tap positions: 05 nos. taps are in the DT., now set at tap position no. 1 (The voltage rating in the primary side at tap position no 1 is 3465 V, no 2 is 3382.5 V, no 3 is 3300 V, no 4 is 3217.5 V & no 5 is 3135 V and secondary voltage rating is 433 Volt)
- Incoming voltages: Incomer voltage is 3.3 KV (from the port supply) which is converted into 415V for phase-phase and 240V for phase-neutral.
- DT Neutral earthing resistance value and other earth resistance values of installation: DT neutral earthing is solidly earthed and other resistance values of installations <1 ohm.
Awards:- INR 8,00,000