2012-Transformer-loss_eva... - Institute of Integrated Electrical ...

INSTITUTE OF INTEGRATED ELECTRICAL ENGINEERS 2
SIC is the cost installing transmission line with a kW of
capacity
Loss Cost Rate refers to NLLCR or LLCR or
ALCR1/ALCR2
FCRG is the Fixed Charge Rate of Generating Plant
FCRT is the Fixed Charge Rate of Transformer
FCRS is the Fixed Charge Rate of Transmission
h is the number of hours per year that transformer is
energized
The Fixed Charge Rate of Plant/Transformer refers to that
portion of investment needed per year to support the capital
investment. In its simplest form, it represents the required
yearly income from the investment. Its components are as
follows;
1) Minimum Acceptable Rate of Return
2) Annual Cost of Depreciation and
3) Taxes
For purposes of this study, FCRT and FCRS are equated
to NGCP’s Weighted Average Cost of Capital (WACC) for
the second regulatory period which is 15.87%. FCRG is set
equivalent to 15%, NEDA’s Social Discount Rate.
The numerator in the equation for the Loss Cost Rate
represents the cost per year to provide a continuous kW
of loss. The first term (GIC × F CRG + SIC × F CRS)
represents that portion of investment cost on a generation and
transmission needed per year to support transformer losses
while the second term represents the cost of the energy under
the present prevailing energy cost. For Luzon, the current year
energy cost, CYEC, is set to $0.1444/kWh This is based on
P7.04/kWh 2 energy rate and P48.65/$1 3 peso-dollar exchange
rate.
III. NO LOAD LOSS COST RATE
Following the principles in Section II, the No Load Loss
Cost Rate is determined as follows;
NLLCR =
(GIC×F CRG + SIC×F CRS) + LECN
ET ×F CRT ×IF
Except for ET and IF terms in the denominator, the formula
for NLLCR is similar to the equation for transformer
loss in Section II. Note that LECN, the Levelized No Load
Energy cost, is the energy portion in Section II equivalent
to US$ 1,573.43/kWyear for Luzon. LECN is determined in
Section VI. ET and IF are dimensionless factors introduced
to reflect the Efficiency of Transmission and Increase Factor
respectively. ET is determined through power flow simulations
and is set to 0.9783 for Luzon Grid. To simplify calculations,
IF is set to 1.007 4 and only reflects project overhead cost.
By introducing ET, the calculated energy, in terms of cost
is marked-up to include other costs dissipated through inefficiency.
IF further increments this cost in proportion to project’s
overhead cost.
2 Figures from PSALM
3 Exchange rate forecast from Economist Intelligence Unit as used by NGCP
in the 3rd Reg. Filing
4 Based on actual budget
Values for other variables are as follows;
Generation Installation Cost GIC = $1,600/kW
Generation Installation Cost SIC = $2.74/kW 5
Solving for NLLCR for Luzon Grid;
NLLCR =
(1, 600×0.15 + 2.74×0.1444) + 1, 573.43
(0.9783×0.1587×1.007)
NLLCR = $11, 601.60/kW
IV. LOAD LOSS COST RATE
For the Load Loss Cost Rate, there is a need to remove
the impact of the Availability Factor AF 6 from LECN, as
calculated in Section VI since for this loss rate Transformer
Loading Factor TLF will be used. Modifying LECN in this
manner results to LECL or the Levelized Load Energy Cost,
LECL is determined as follows:
LECL = LECN
AF
=
1, 573.43
0.9897
1, 589.8
=
kW
year
With the denominator remaining the same as that for No-
Load Loss Cost Rate, the equation for the Load Loss Cost
Rate is:
LLCR = (GIC×F CRG + SIC×F CRS)×P RF 2 ×P UL 2
(ET ×F CRT ×IF )
2
LECL×T LF
+
(ET ×F CRT ×IF )
The new terms in the numerator are dimensionless adjustment
factors introduced to enable realistic assessment. The
Peak-Per Unit Load (PUL) relates demand-associated losses to
full rated transformer and not to the peak transformer load 7 . It
is the average of yearly peaks over the lifetime of transformer
divided by the rating at which the load losses are guaranteed
to be tested. For this study, load losses are assumed to be
tested at full-load transformer rating. Using load forecast data
for 2009, PUL is set to 1.114 for Luzon.
The Peak Responsibility Factor (PRF) is the transformer’s
load during system peak 8 , divided the transformer’s peak load.
This factor is intended to compensate for the transformer
peak load losses not occurring at the system peak losses.
The rationale is, if the entire transformer peak does not
occur during the system peak, then there is no need to put
up additional generation since the transformer load and its
losses could be supplied by the system. That is reason behind
inclusion of PRF in the demand portion of the loss assessment
equation. The data used in the determination of this parameter
5 Based on $27,365.00/km, 2008 Price Level of 5km, 69kV ST/SC, 1-336.4
MCM ACSR
6 Availability Factor AF is the expected percentage of time the transformer
will be energize. AF = 0.9897
7 Guide for the Evaluation of Large Power Transformer Losses, USDA
8 System Peak assumed to occur at 1900H