Transcript POWER QUALITY IN THE PHILIPPINES

POWER QUALITY AND THE
PHILIPPINE GRID CODE
Power Quality during the late 90’s
 PQ was dominated by Fluke and LEM
 Power Utilities has just started talking about
standards to be followed
 National Power Corporation, Meralco - main
proponents in the utility companies involved
in setting up the standards
 A very few manufacturing companies are
aware of the need of PQ for their facilities
Power Quality in the 2000’s
 More players came in (RPM, Dranetz-DMI, Hioki,
EIG, AEMC, Unipower, etc)
 Philippine Grid Code was published and started
to be implemented (2001)
 Philippine Distribution Code was published and
started to be implemented (2001)
 TransCo was separated from the National Power
Corporation (2003)
 National Power Corporation, TransCo, Meralco became models in the PQ standardization
Power Quality in the 2000’s (cont..)
 Privatization of the government owned
Power Plants
 TransCo became the National Grid
Corporation of the Philippines (NGCP)
 Models for PQ originates from NGCP and
Meralco using the PGC and PDC as basis for
the standards
 Manufacturing facilities engineers became
aware of the need to implement PM involving
PQ
Grid Code PQ Requirements
 Power Quality Performance (Article 3.2)
 System Frequency Deviation
 Voltage Magnitudes Variations
 Voltage Fluctuations
 Harmonic Frequencies
 Voltage Unbalance
 Transient Voltage Variations
Grid Code PQ Requirements
 Frequency Variations
 Nominal Frequency – 60 Hz
 Maintain Frequency during normal conditions
 Limits: 59.4 Hz ≤ f ≤ 60.6 Hz
Grid Code PQ Requirements
 Voltage Variations
 Long Duration Voltage Variation
Duration greater than 1 minute
Undervoltage (RMS value is less than or equal to 90%
of the nominal value)
Overvoltage (RMS value is greater than or equal to
110% of the nominal value)
95% ≤ RMS nominal voltage ≤ 105%
Grid Code PQ Requirements
 Voltage Variations
 Short Duration Voltage Variation
Duration greater than ½ cycle but not exceeding 1
minute
Voltage Swell (RMS value increases between 110%
and 180% of the nominal value)
Voltage Sag (RMS value decreases between 10% and
90% of the nominal value)
Grid Code PQ Requirements
 Voltage Fluctuation
 Random amplitude changes of RMS value
between 90% to 110% of the nominal voltage
 Voltage fluctuation shall not exceed 1% of the
nominal voltage for every step change, which
may occur repetitively
 Large voltage fluctuation other than a step
change maybe allowed up to 3% provided will
not put risk to the Grid or any User system
Grid Code PQ Requirements
 Flicker Severity
 Short Term Flicker Severity (PST) – short duty
cycle fluctuation,shall be computed over a 10minute period
 Short Term Flicker Severity (PLT) – long and
variable duty cycle fluctuation, derived from
PST levels
Grid Code PQ Requirements
 Harmonics
 Total Harmonic Distortion (THD) – ratio of the
RMS value of the harmonic content to the
RMS value of the fundamental quantity in
percent
Grid Code PQ Requirements
 Harmonics
 Total Demand Distortion (TDD) – ratio of the
RMS value of the harmonic content to the
RMS value of the rated or maximum
fundamental quantity in percent
Grid Code PQ Requirements
 Voltage Unbalance
 Refers to negative sequence unbalance factor
or zero unbalance factor
Negative Sequence Unbalance Factor = Negative Sequence Components of Voltages
Positive Sequence Components of Voltages
Zero Sequence Unbalance Factor = Zero Sequence Components of Voltages
Positive Sequence Components of Voltages
 Compliance:
Voltage Unbalance ≤ 1% for 115 kV and above
Voltage Unbalance ≤ 2.5% for 69 kV and below
Grid Code PQ Requirements
 Transient Voltage Variations
High frequency overvoltages shorter in duration
compared to short duration voltage variations
In-frequent short-duration may exceed levels of
harmonics limits provided such increases do not
compromise service to End-users or cause
damage to Grid equipment
In-frequent short-duration with a maximum value of
2% maybe permitted for Voltage Unbalance
subject to terms of Connection Agreement
END OF PRESENTATION
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