1. Power quality management for induction furnace foundry
Mr.Danaisak Tangsakha
Provincial Electricity Authority (PEA)
Thailand

2. Topic Introduction Problem & Mitigation Techniques Conclusion
Provincial Electricity Authority, Thailand
5 December 2018

3. What is “Harmonics Voltage”?
A sinusoidal voltage with a frequency equal to an integer multiple of the fundamental frequency of the supply voltage (EN50160) Order 3 : 3 × 50 Hz = 150 Hz
Provincial Electricity Authority, Thailand
5 December 2018

4. Where is the source of the harmonics?
(a) Power flow at the fundamental frequency
(b) Harmonic power flow
Provincial Electricity Authority, Thailand
5 December 2018

5. Single Line Diagram PEA System 115 kV
INDUCTION
FURNANCE
LOAD
GENERAL
LOAD
GENERAL
LOAD
GENERAL
LOAD
GENERAL
LOAD
Provincial Electricity Authority, Thailand
5 December 2018

6. INDUCTION FURNANCE Induction Furnace inverter 24 pluse
Ideal harmonic h=p±1 order 23, 25
4 unit and Full Load 3 unit (39.80 MW)
Provincial Electricity Authority, Thailand
5 December 2018

7. INDUCTION FURNANCE PEA System 115 kV
Provincial Electricity Authority, Thailand
5 December 2018

8. Load Characteristic 10 pm – 9 am
TOU rate : Customer Loads operated in off-peak period
Provincial Electricity Authority, Thailand
5 December 2018

9. Problem
Induction Furnace Load THD over limit Harmonics Standard in Thailand
Adjacent 22 kV Customers complaints included flickering lights, UPS alarms, drive trips, impairment of electronic equipments
Provincial Electricity Authority, Thailand
5 December 2018

10. Total Harmonic Distortion ,THD
Provincial Electricity Authority, Thailand
5 December 2018

11. Harmonics Standard in Thailand
Table 1 Harmonics Current Limit (Base 1,000 MVA)
Tolerances 10% or 0.5 A , 2 order
PRC - PQG - 01 / 1998
Provincial Electricity Authority, Thailand
5 December 2018

12. Harmonics Standard in Thailand
Table 5-2 limit of Total Harmonic Distortion VoltageTHDv (%)
Point of Common Coupling : PCC
(kV)
Total Harmonic
Distortion Voltage
THDv (%)
Individual Harmonic
Distortion Voltage(%)
Odd
Even
0.4 5 4 2
11 and 12 3
1.75
22 ,24 and 33 1 69
2.45
1.63
0.82
115 and above
1.5
0.5
PRC - PQG - 01 / 1998
Provincial Electricity Authority, Thailand
5 December 2018

13. Voltage Fluctuation Standard in Thailand
Point of Common Coupling
: PCC (kV)
Pst
Plt
Below 115 kV
1.0
0.8
More than 115 kV
0.6
Pst ; Short-Term Severity Values (10 minutes)
Plt : Long-Term Severity Values (2 hours)
PRC - PQG - 02 / 1998
Provincial Electricity Authority, Thailand
5 December 2018

14. Mitigation Techniques
Connect to Network
Monitoring
Harmonic Filter
Simulation
July,2009
Sep,2009
Provincial Electricity Authority, Thailand
5 December 2018

15. Network Configuration
230/115 kV
230/115 kV
BPA
SPA
115/22 kV
115/22 kV
NPA
NPB
LNS
END LINE
Provincial Electricity Authority, Thailand
5 December 2018

16. Monitoring With out Harmonics Filter
Harmonics current at PCC:115kV at Ling Nan Steel for 1 EAF with out Harmonics Filter
Case
MVA
Harmonics Order
Base 1 2 3 4 5 6 7 8 9
With out Harmonics Filter -
70.28
5.85
6.33
7.91
6.55
6.6
2.48
0.91
1.22
With Harmonics Filter
Harmonics Current Limit at Base 1,000 MVA
1,000
Ih limit Base on 115kV Nakorn Pathom2
1,984
9.92
7.99
5.99
3.99
Remark ×
Provincial Electricity Authority, Thailand
5 December 2018

17. Monitoring With out Harmonics Filter
Harmonics current at PCC:115kV at Ling Nan Steel for 1 EAF with out Harmonics Filter
Case
MVA
Harmonics Order
Ih rms
Base 10 11 12 13 14 15 16 17 18 19
With out Harmonics Filter -
1.04
3.95
0.92
2.98
0.49
0.65
0.73
1.18
0.57
0.97
16.19
With Harmonics Filter
Harmonics Current Limit at Base 1,000 MVA
1,000 1 3
10.34
Ih limit Base on 115kV Nakorn Pathom2
1,984 2
5.99
20.63
Remark
Provincial Electricity Authority, Thailand
5 December 2018

18. Harmonic Filter Tuned Filter Order 4 and 5 High pass filter Order 6
Provincial Electricity Authority, Thailand
5 December 2018

19. Simulation by DIgSILENT
On Site Tuned Filter
Provincial Electricity Authority, Thailand
5 December 2018

20. Harmonic Filter 4th 5th 6th Provincial Electricity Authority, Thailand
5 December 2018

21. Harmonic Filter Provincial Electricity Authority, Thailand
5 December 2018

22. Simulation by DIgSILENT
Provincial Electricity Authority, Thailand
5 December 2018

23. Monitoring and Simulation
Case
Harmonic Order 1 2 3 4 5 6 7 8 9
Ih limit Base on 115kV
Nakhon Pathom2 -
9.92
7.99
5.99
3.99
With Harmonics Filter
198.89
1.14
7.70
1.93
5.20
0.91
1.81
0.45
Simulation : DigSILENT
177.1
0.79
3.69
0.36
0.03
0.12
0.21
0.83
1.44
Remark
Case
Harmonic Order 10 11 12 13 14 15 16 17 18 19
Ih limit Base on 115kV
Nakhon Pathom2 2
5.99
With Harmonics Filter
0.45
2.49
1.81
0.68
Simulation : DigSILENT
0.07
4.1
0.12
1.39
0.51
0.5
0.6
0.83
1.44
0.33
Remark
Provincial Electricity Authority, Thailand
5 December 2018

24. Conclusion
The network configuration in this case reduced the affect to nearby customers and also improved voltage level.
The results of harmonic filters are
dramatically reduced voltage distortion on the 22 kV and not to affect the nearby customer
Customer run 3 unit from 4 unit because harmonic filters design for 3 unit.
Provincial Electricity Authority, Thailand
5 December 2018

25. Thank you for your attention…
Provincial Electricity Authority, Thailand
5 December 2018