Table 1:
Allowable limit for distribution transformer (DT) loading, voltage regulation, and harmonics [
11
,
12
].
Attributes
Recommended limit
Regulatory standard
DT loading
80% of the installed capacity, withstand up to 120%
Inverter capacity
10 kVA for single phase
30 kVA for three phase
AS 4777 [
11
]
Voltage regulation
Allowable limit is
6%, that is, 240 V
6% for single phase and 415 V
6% for three-phase systems
Voltage rise due to PV at PCC is 1% at 240 V line to neutral voltage.
AS 4777 [
11
]
Harmonics
THD up to 50th harmonic should be less than 5%
voltage harmonic limit to 8%.
AS 4777 [
11
]