Simplified PWM charge controller sizing and selection/es

Un controlador de carga PWM está clasificado para funcionar a un tensión CC del sistema y una corriente máxima en especifico. Los módulos FV diseñados para funcionar a esta tensión de CC del sistema deben conectarse en circuitos de fuente FV en paralelo para lograr el la capacidad mínima de la fuente FV y el controlador de carga, por lo tanto, debe dimensionarse para manejar esta cantidad de corriente. Si se excede la clasificación actual de un controlador de carga PWM, puede dañarse o destruirse.

Paso 1: Determine la potencia nominal del módulo fotovoltaico y la configuración de la serie

La tensión CC dle sistema limita las opciones de módulos y configuraciones que son posibles con un controlador de carga PWM. A continuación se muestra una tabla con la cantidad de módulos que se pueden conectar en serie para cada circuito de fuente FV dependiendo de la tensión del sistema de CC.

Tensión de CC del sistema	36 celdas	60 celdas	72 celdas
12 V	1	—	—
24 V	2	—	1
48 V	4	—	2

PV module power rating	=

Number of modules in series	=

Step 2: Determine proposed module configuration

This calculation will give a minimum number of PV modules - the result should always be rounded up. Different modules sizes and configurations can be explored to find the optimal design.

Number of PV modules	= Temperature adjusted minimum PV source size ÷ PV module power rating (Step 1)

The final number of PV modules should always be larger than this value - the result should always be rounded up.

Number of PV source circuits	= Minimum number of PV modules ÷ Number of modules in series (Step 1)

Step 3: Total PV source current

This calculation will give a minimum current rating to use as a basis for selecting the charge controller. The Isc rating of the PV module can be found on its specifications sheet. This value is multiplied by a required 1.25 safety factor to make sure the charge controller can handle periods of excessive current due to high irradiance.

Total PV source current	= Final number of PV source circuits (Step 2) × Isc rating of chosen module (Step 1) × 1.25

Step 4: Select a charge controller

A single charge controller is the simplest and cheapest option, but for larger systems multiple charge controllers often are used in parallel. The final chosen charge controller should:

1. Function at the DC system voltage.
2. The charge controller(s) should have a total current rating that is larger than the minimum current rating (Step 2). Common charge controller current ratings: 4.5 A, 5 A, 6 A, 10 A, 12 A, 15 A, 20 A, 25 A, 30 A, 35 A, 40 A, 45 A, 50 A, 55 A, 60 A.

Final charge controller current rating	=

The result of the following equation should always be rounded up.

Number of charge controllers	= Total PV source current (Step 3) ÷ Final charge controller current rating

Step 5: Determine final PV source power rating

The total power rating of the PV source can be calculated by multiplying the power rating of the chosen PV module by the final number of PV modules (Step 3).

PV source power rating	= PV module power rating (Step 1) × Final number of PV modules (Step 3)