Performance Evaluation of Small Photovoltaic Stand-Alone Systems

In this paper, the authors report the performance test results of small Photovoltaic (PV) stand-alone systems according to IEC 62124: Photovoltaic Stand-alone System — Design verification. They also give a brief introduction of test procedures and pass criteria. These tests were carried out at the PV system laboratory in Photovoltaic and Wind Power Systems Quality Test Center, Chinese Academy of Sciences (PWQTC). The object of the test is to verify system design and performance of stand-alone photovoltaic systems. The performance test evaluates systems in the several aspects such as battery usable capacity, functional test, recovery test, system balance point, days of autonomy, etc. The results show that some systems failed in their performance test although they have qualified individual components. Unreasonable design of systems is considered as a main reason to cause failure. The other reasons are considered as battery quality problem, inappropriate setting for controller set points and controller quality problems.