The WDPF system is a kind of DCS

which had been brought forth by Westinghouse Corporation in USA at late 1980s

and being more widely used in China

most of them having been in operation up to more than ten years.Owing to their components being outdated

the spare parts

such as working stations and distributed processing units

are now not supplied and supported by the manufactory again.For this

some retrofit schemes have been put forward for upgrading the WDPF system

and several schemes for technically retrofitting the WDPF system being analysed and compared

then a comparatively reasonable one being determined.providing reference for technically retrofitting the WDPF system in power plants.