Describe the bug
The CEC grid supporter list includes a field titled "Voltage Maximum". This quantity is the maximum DC voltage at which inverter efficiency is measured, which is not the same as the maximum input DC voltage. For example, for inverter "SMA America STP 33-US-41 [480V]", Voltage Maximum is given as 800Vdc, but the inverter maximum DC input voltage is 1000 Vdc, per the datasheet.
Private communication with SMA America informs that the inverter maximum DC input voltage is not requested by the CEC.
The problem is with how SAM uses "Voltage Maximum" to suggest and check string length. For example, this line
modules_per_string_max = floor( inverter.vdcmax / voc_max_design );
An alternative is to assume that the maximum DC input voltage is 125% of "Voltage Maximum" (private communication with SMA) but I don't know if this rule of thumb works for all inverters. Another alternative is to remove the string length calculations.
Describe the bug
The CEC grid supporter list includes a field titled "Voltage Maximum". This quantity is the maximum DC voltage at which inverter efficiency is measured, which is not the same as the maximum input DC voltage. For example, for inverter "SMA America STP 33-US-41 [480V]", Voltage Maximum is given as 800Vdc, but the inverter maximum DC input voltage is 1000 Vdc, per the datasheet.
Private communication with SMA America informs that the inverter maximum DC input voltage is not requested by the CEC.
The problem is with how SAM uses "Voltage Maximum" to suggest and check string length. For example, this line
An alternative is to assume that the maximum DC input voltage is 125% of "Voltage Maximum" (private communication with SMA) but I don't know if this rule of thumb works for all inverters. Another alternative is to remove the string length calculations.