If a failure in the components of a photovoltaic (PV) system

such as PV module

controller

inverter

load

cable

etc. goes undetected and uncorrected

it can seriously affect the efficiency

safety

and reliability of the entire PV power plant. In addition

fires can occur if specific faults

such as arc

ground

and line-to-line faults remain unresolved. Therefore

PV system (PVS) fault diagnoses are crucial for PV power plant reliability

efficiency

and safety. Many fault diagnosis methods and techniques for PVS components have been developed. In addition

with the development of PV devices

more advanced and intelligent diagnostic technologies are continuously being researched and developed. However

a systematic and thorough analysis

summary

and conclusion are still urgently required. Thus

this paper introduces the types

causes

and impacts of PVS faults

and reviews and discusses the methods proposed in the literature for PVS fault diagnosis

and in particular

failures in PV arrays. Special attention is paid to the optimization direction of various fault diagnosis methods under different priorities

and their limitations

feasibility

complexity

and cost-effectiveness. Finally

challenges and suggestions are put forward for future research.