power quality - dips and interrutions
TRANSCRIPT
Saxion University of Applied Sciences
POWER QUALITY
Deel A
Jentje Bootsma
Power Quality Dips and Interruptions
Power Quality
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Dips and Interruptions
Introduction
Dips/Interruptions
UPS-DC/UPS-AC
Harmonics
Power Quality
Energie efficiëntie
Kosten
Power Quality
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Dips and Interruptions
Voltage dips are defined as sudden reduction in voltage to lower voltages for a short period of time, followed by recovery to the original voltage.
Definition of Voltage Dips
Power Quality
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Dips and Interruptions
Short interruptions are defined as a disappearance of AC voltage for a short period of time, typically not exceeding 1 minute, followed by recovery to the original voltage. Short interruptions can be considered as voltage dips to zero volts.
Definition of Short Interruptions
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Dips and Interruptions
Voltage variations are gradual changes of the supply voltage to a higher or lower value than the rated voltage. The duration can be short or long.
Definition of Voltage variations
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Dips and Interruptions
• Stroke of lightning on • High voltage • Medium Voltage • Low voltage
• Short circuit • High voltage • Medium Voltage • Low voltage
• Cable braking • Starting large motors, transformers
Voltage dips can’t be avoided and will propagate through the grid
Causes of dips
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Dips and Interruptions
Influences decreases with distance
Propagation of dips
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Dips and Interruptions
Normal operation
10 ms 1 min
1%
90%
100%
110%
Under voltage Voltage dip
Short interruptions
3 min
Long interruptions
Over voltage
Voltage variations, dips and transients
Definitions: NEN-EN 50160
No requirements
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Dips and Interruptions
Dip profile
120 ms
Dips
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Dips and Interruptions
Power Quality
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Dips and Interruptions
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Dips and Interruptions
IEC 61000-4-11
Immunity testing
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Dips and Interruptions
IEC 61000-4-11 Classification of test results
• Performance Criteria A ‘Performance within specification limits’ • Performance Criteria B ‘Temporary degradation which is self-recoverable’ • Performance Criteria C ‘Temporary degradation which requires operator intervention’ • Performance Criteria D ‘Loss of function which is not recoverable’