IEC TS 63156 pdf – Photovoltaic systems – Power conversion equipment performance – Energy evaluation method
1 Scope
This document describes the procedure for evaluating the energy conversion performance of stand-alone or grid-connected power conversion equipment (PCE) used in PV systems. This procedure includes the calculation of inverter performance to anticipate the energy yield of PV systems. This evaluation method is based on standard power efficiency calculation procedures for PCE found in IEC 61683 and IEC 62891, but provides additional methods for evaluating the expected overall energy efficiency for a particular location given solar load profiles. This document can be used as the energy evaluation method for PCE in IEC TS 61724-3, which defines a procedure for evaluating a PV system’s actual energy production relative to its modeled or expected performance.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
IEC 61683, Photovoltaic systems – Power conditioners – Procedure for measuring efficiency
IEC TS 61836, Solar photovoltaic energy systems – Terms, definitions and symbols
IEC 62891, Maximum power point tracking efficiency of grid connected photovoltaic inverters
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC TS 61836 as well as the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
IEC Electropedia: available at http://www.electropedia.org/
ISO Online browsing platform: available at http://www.iso.org/obp
3.1
irradiance
G
electromagnetic radiated power per unit area
Note 1 to entry: Unit: W•m −2.
3.2
in-plane irradiance
G I
total irradiance on the plane of a PV cell or module
3.3
rate of change of irradiance
R
change in irradiance amount during 1 s
Note 1 to entry: Unit: W•m −2 •s −1.
3.4
rated input voltage
V DC,r
rated input voltage specified by the manufacturer, to which other data sheet information refers
Note 1 to entry: Unit: V.
3.5
rated input power
P DC,r
rated input power of the power conversion equipment, which can be converted under continuous
operating conditions
Note 1 to entry: Unit: W.
3.6
rated output voltage
V AC,r
utility grid voltage to which other data sheet information refers
Note 1 to entry: Unit: V.
3.7
rated output power
P AC,r
active power that the power conversion equipment can output during continuous operation
Note 1 to entry: Unit: W.
3.8
PV simulator MPP-Power
P MPP,PVS
MPP power provided by the PV simulator
Note 1 to entry: Unit: W.
3.9
input power
P DC
measured input power of the device under test
Note 1 to entry: Unit: W.
3.10
PV simulator MPP voltage
V MPP,PVS
MPP voltage provided by the PV simulator
Note 1 to entry: Unit: V.
3.11
input voltage
V DC
measured input voltage of the device under test
Note 1 to entry: Unit: V.
3.12
PV simulator MPP current
I MPP,PVS
MPP current provided by the PV simulator
Note 1 to entry: Unit: A.
3.13
input current
I DC
measured input current of the device under test
Note 1 to entry: Unit: A.
3.14
output power
P AC
measured AC output power of the device under test
Note 1 to entry: Unit: W.
3.15
output voltage
V AC
measured AC voltage of the device under test
Note 1 to entry: Unit: V.
3.16
output current
I AC
measured AC output current of the device under test
Note 1 to entry: Unit: A.
3.17
MPPT efficiency
η MPPT
ratio of the energy drawn by the device under test within a defined measuring period T M to the energy provided theoretically by the PV simulator at the maximum power point (MPP):
P DC (t) is the instantaneous value of the power drawn by the device under test, in kW;
P MPP (t) is the instantaneous value of the MPP power provided theoretically by the PV simulator, in kW.
Note 1 to entry: Unit: dimensionless, usually expressed as a percentage, %.
3.18
energy conversion efficiency
η CONV
ratio of the energy delivered by the device under test at the AC terminal within a defined measuring period T M to the energy received by the device under test at the DC terminal: