Harmonic Mitigating Transformer Cost-Effectiveness Evaluation Tool
a
Inputs:
Transformer Rating (kVA)
Secondary Voltage (V)
Load (kW)
Load Power Factor (%)
Full Load I2R Losses in Primary (W)
Full Load Eddy Current Losses in Primary (W)
HMT Full Load Primary Losses (W)
Load Hours per Day
Operating Days per Year
Utility Energy Rate ($/kWh)
Utility Demand Rate ($/kW-mo)
>HMT Capital Cost Premium ($)
Harmonic
Number (h)
Harmonic
Current I
h
(amps)
1
3
5
7
9
11
13
15
17
19
21
23
25
Results:
Current Total Harmonic Distortion (%)
Load (kVA)
Load (%)
Phase Current (@60 Hz)
K Factor
Full Load Eddy Current Losses in Primary (W)
Full Load Total Losses in Primary (W)
Load Losses in Primary at Input Load Level
Load Losses in Primary for K=1 at Input Load Level
Harmonic-related Losses in Primary (kW)
Non-Harmonic Related Savings/Losses (kW)
Total Direct HMT Savings (kW)
Avoided Cooling Power (kW)
Annual Energy Savings ($)
Annual Demand Savings ($)
Total Annual Savings ($)
Simple Payback (years)
Per-Unit
Current
b
(I
h-pu
)
K Factor
Notes:
a. This example assumes a completely balanced nonlinear load and that the difference in core losses between the HMT and the alternative transformer is negligible.
b. The per-unit current at any harmonic is equal to the magnitude of that current divided by the square root of the sum of the squares of the currents at all frequencies.
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