SE Engr. Technical Specifications 3

Question 1

What does the CEC weighted efficiency on an inverter datasheet represent?

Accepted Answer

Efficiency averaged over several load levels, weighted to reflect typical operation

Answer

CEC weighted efficiency combines efficiencies at several power levels using weights that reflect how often the inverter typically runs at each level.

Question 2

What does the 'MPPT voltage range' on an inverter datasheet specify?

Accepted Answer

The DC input voltage window in which the inverter can track maximum power

Answer

String Vmp must stay inside the MPPT window across all temperatures for the inverter to harvest full power.

Question 3

A system pairs 12.5 kW DC of modules with a 10 kW AC inverter. What is the DC/AC (inverter loading) ratio?

Accepted Answer

1.25

Answer

12.5 kW DC / 10 kW AC = 1.25.

Question 4

Which maximum DC system voltage is most common in modern US utility-scale PV plants?

Accepted Answer

1500 V

Answer

Utility-scale plants have standardized on 1500 V DC to allow longer strings and lower balance-of-system costs.

Question 5

Which standard defines interconnection and interoperability requirements for distributed energy resources connected to the US grid?

Accepted Answer

IEEE 1547

Answer

IEEE 1547 (2018 revision) sets the performance requirements for DER interconnection, including ride-through and voltage/frequency support.

SE Engr. - Solar Energy Engineering Certification Practice Test