The PV industry has been growing rapidly for many years and we are now seeing many new manufacturers coming on line. In more recent years we have seen an emphasis on grid connected systems with government subsidy schemes, feed in tariffs and climate change driving industry growth. We have seen inverter manufacturers driving the PV array voltages up to 800 and 1000V dc for reasons of efficiency and cost reduction.
At the same time the industry has now had product out in the field for an extended period and we are seeing the affects of aging of modules, connectors and wiring system. All of these affects combined are leading to an increase in faults developing in systems. The high dc voltages lead to significant stress on insulation systems and the possibility of arcing faults developing. Safety issues for dc systems are much more significant than for ac systems because of arcing and corrosion issues that can develop.
Fusing is also a very important issue and difficult to craft accurately in PV system so that adequate protection is provided.
This paper explores the range of safety issues being faced by the industry and explores the response in terms of module and safety standards and new safety devices to improve array safety.