NB/T 10394-2020Specification for photovoltaic power generation system performance (English PDF)

3.1 Standard test condition

The battery temperature is 25 °C, the irradiance is 1000 W/m², and the air quality is AM1.5.

Note: The spectral irradiance distribution meets the requirements of GB/T 6495.3.

3.2 Nominal power of the rear side of a bifacial PV module

The peak power on the back of the module measured under standard test conditions, in units of peak watts (Wp).

3.3 Installation capacity of PV modules

For single-sided modules, it refers to the sum of the nominal power of the photovoltaic modules installed in the photovoltaic power generation system, and the unit is the peak watt (Wp).

For double-sided modules, the front installation capacity refers to the sum of the nominal power of the front of the photovoltaic modules installed in the photovoltaic power generation system, and the unit is peak Watt (Wp), its back installation capacity refers to the sum of the nominal power on the back of the photovoltaic modules installed in the photovoltaic power generation system, and the unit is peak watts (Wp).

The installed capacity of a bifacial module photovoltaic power generation system refers to its frontal installed capacity.

3.4 Rated capacity

The sum of the rated active power of the inverters installed in the photovoltaic power generation system, in watts (W).

3.5 PV power to inverter power ratio

The ratio of the installed capacity of the photovoltaic system to the rated capacity.

3.6 Mismatch losses

The series mismatch power loss of all photovoltaic modules in the photovoltaic module branch, the parallel mismatch power loss of the photovoltaic module branch, and the combiner box parallel The sum of power loss in connection mismatch.

3.7 DC cable losses

The sum of the power loss of all DC cables from the output end of the photovoltaic module to the input end of the inverter.

3.8 AC cable losses

The power loss of all AC cables from the output end of the inverter to the step-up transformer, and the step-up transformer to the grid-connected point in the grid-connected photovoltaic power generation system with.

3.9 System failure and maintenance losses

Power generation caused by component, inverter, step-up transformer and other equipment failures, maintenance needs, and management problems in the operation of photovoltaic power generation systems loss.

3.10 System external losses of photovoltaic power generation system

Photovoltaic power generation system due to the power grid, natural disasters and other external factors caused the loss of power generation

3.11 Electric energy tariff point

The property boundary between the photovoltaic power generation system and the grid facilities or the transaction settlement point specified in the contract agreement.

3.12 Levelized cost of energy

The discount ratio of all costs incurred by the photovoltaic power generation system during the evaluation period to the total amount of electricity available to the grid, in yuan per kilowatt-hour (CNY/kWh).

3.13 System performance

Refers to the annual equivalent utilization hours of photovoltaic power generation systems, system energy efficiency ratio, levelized electricity cost, unit area efficiency, and external benefits And other indicators.

4.1 Component efficiency

Module efficiency should be the ratio of module power measured under standard test conditions to the product of module area and radiation intensity, the calculation formula as follows. […]

4.2 Double-sided ratio of double-sided modules

The double-sided ratio of the double-sided module should be the ratio of the nominal power on the back of the double-sided module to the nominal power on the front of the double-sided module. The calculation formula is as follows. (2)

4.3 Inverter efficiency

Inverter efficiency includes maximum conversion efficiency and average weighted total efficiency. The maximum efficiency of the inverter is based on the The test and certification result is confirmed. The average weighted total efficiency of the inverter should be calculated according to the following formula.

Note: G represents the total annual radiation exposure, using the multi-year average (generally the 30-year average), and the unit is megajoules per square meter per year (MJ·m-2·a-1)

4.4 Capacity ratio

The volume ratio should be calculated as follows. […]

4.5 DC power loss

The DC power loss index of the photovoltaic power generation system should be the sum of all mismatch losses from the component output to the inverter input and the DC line loss The ratio to the sum of the output power of all components, expressed as a percentage.

4.6 AC power loss

For grid-connected photovoltaic power generation systems, the AC power loss of the photovoltaic power generation system should be all the AC line losses from the output end of the inverter to the grid-connected point And the ratio of the sum of the power loss of the step-up transformer to the sum of the output power of all inverters, expressed as a percentage.

4.7 Selection of solar resource data for photovoltaic power generation system

The calculated value of solar resources of photovoltaic power generation system should be based on at least one complete year of actual measurement data of the solar radiation field observation station.

Count. When the actual measurement data of the solar radiation field observation station is not available, it can represent the long-term observation data of the weather station or the long-term radiation data calculated by the weather station.

The calculation is based on statistical calculation data based on satellite remote sensing data or physical inversion data. Radiation data measurement and processing should meet IEC According to 61724-1, the priority level of solar resource data selection for photovoltaic power generation system is shown in Table 3.