Transcript Melo EDP PT Session 2 – Block III – Question 9.1 Barcelona 12

Barcelona 12-15 May 2003
EDP Distribuição Energia
ASD Immunization to Voltage Dips
Case Study in Cement Industry
Melo EDP PT Session 2 – Block III – Question 9.1
1
Barcelona 12-15 May 2003
General approach
• Electric utility side



Protections optimisation
Split busses and load transfer
Close of HV meshes
• Customer installations side


Implementation of high power quality technologies
with energy storage in critical sectors
Immunization of sensible equipment through software
and hardware techniques
Melo EDP PT Session 2 – Block III – Question 9.1
2
Barcelona 12-15 May 2003
Cement plant characterization
• Cement plant is supplied in HV (60kV) by two
independent feeders
• Main loads are mills, fans, compressors and
pumps
• The application of ASD in fans presents a large
energy saving potential and an excellent
improvement of the process flexibility
• Main fans of the production process are driving by
ASD
Melo EDP PT Session 2 – Block III – Question 9.1
3
Barcelona 12-15 May 2003
Kinetic energy recovery on fans
• Tripping of critical fans with voltage dips can
cause the whole production process stop
• We are attending the implementation of KER
technique in cement industry
• This ride-through technique was applied only in
ASD that drive critical fans
• Voltages and power of machines


Voltage: 690V and 400V
Power: 800kW, 216kW, 200kW and 160kW
Melo EDP PT Session 2 – Block III – Question 9.1
4
Barcelona 12-15 May 2003
ASD behaviour with voltage dip
AC Voltage
DC Voltage
100%
50%
Motor Speed
t1
t2
t1 – t3: Voltage Dip
t3
t
t2 – t3: Kinetic Energy Recovery
Melo EDP PT Session 2 – Block III – Question 9.1
5
Barcelona 12-15 May 2003
Conclusions
• In the cement plant the voltage dips severity
is lower (supplied in HV)
• Kinetic energy recovery is an easy and fast
immunity technique without investment
• The analysis period after implementation is
still reduced but we hope a better operation
• The ride-through capability improvement
should start in critical loads
Melo EDP PT Session 2 – Block III – Question 9.1
6