UWE Bristol Engineering showcase 2015

Rhodri Taylor
BEng (Hons) Electrical and Electronic Engineering
Project Supervisor
Dr. Hassan Nouri
Fault Detection & Modelling of Solar PV Modules
Introduction
The consumption of non-renewable energy
sources, such as oil & gas have been rapidly
increasing for a number of years and with these
being a finite resource there has been a drive for
alternative energies in recent years. .
Solar PV cells convert sunlight into direct current
(DC) electricity using semiconductor materials,
mainly silicon. The conversion of solar energy by
this method is seen as a favourable option as it is
a direct conversion; this means that there are no
mechanical moving parts or environmental
emissions during the conversion from sunlight to
electricity. However, PV cells have a number of
certain drawbacks such as low power-rating, high
cost, low reliability, etc. The low reliability is due
to the possibility of a fault being hidden in the
solar PV array, reducing its lifetime and
efficiency.
It is these common PV faults that this
investigation will focus on, testing fault modelling
& detection techniques using PSCAD and
creating a HMI management system for remote
monitoring.
PSCAD Modelling
Two PSCAD PV array models were designed as
part of this investigation, one was used to
replicate previous experimental results and the
second was based on a grid-tied PV array. Fault
models were also developed to simulate a typical
DC arc fault.
Fault Detection
Various fault detection methods were used
during this investigation to detect all of the
simulated faults. An FFT was used to analyze the
harmonics of the PV system current. Analysis of
these results also showed that certain faults can
be identified by fluctuations of individual
harmonic components.
During a parallel arc fault the 3 rd and 5 th
harmonics peaked unlike during other faults
allowing not only the detection of the fault but
the type of fault can be identified also.
HMI Monitoring System
The HMI monitoring system designed in this
investigation is based on the Siemens WinCC
platform and uses an S7-1200 CPU to handle the
fault detection and management of the
networking interface. This system allows the
remote monitoring of a PV array and provides
live diagnostic information to the user.
Project summary
The main aim of this investigation is to model and
simulate various faults & fault detection techniques
that commonly occur in solar PV modules and arrays
and to develop a system to remotely monitor and
manage a PV installation.
Project Objectives
To create a simulation module of a typical PV array to
test fault detection.
To develop a DC arc fault model in PSCAD and verify
results.
Replicate experimental results using the designed
PSCAD models.
Test common PV faults on grid-tied system using
PSCAD simulation models.
Design HMI management system for remote
monitoring of PV array on Siemens platform.
Collate results & findings of different faults and
detection techniques.
Project Conclusion
This investigation involves the design of accurate
PSCAD models of a grid-tied PV array and replication
of experimental fault models.
These designed fault models are verified against the
experimental work that they are based on.
Various fault detection techniques are used to detect
the simulated faults in PSCAD including the use of a
FFT.
A HMI management system is also designed to allow
the remote monitoring and detection of a typical PV
array.