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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Harmonic Filter Provincial Electricity Authority, Thailand 5 December 2018

Simulation by DIgSILENT Provincial Electricity Authority, Thailand 5 December 2018

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

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

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