09-10-2012, 10:31 AM
Design of PI Controller For a Stand alone PV System in AC Voltage
Applications
Design of PI Controller.pdf (Size: 284.58 KB / Downloads: 91)
Abstract
This paper focuses on the renewable energy
system PV (Photo Voltaic) Cell in stand alone model. The
system consisting of PV cell, DC-DC Boost converter, and
Inverter coupled to the load system. An 18V photovoltaic cell
and a DC-DC boost converter is designed for the purpose of
boosting the PV cell output voltage. An inverter is used to
convert DC to AC for application purposes. A control
technique is adopted for controlling the entire converter
system. The PI controller is designed for DC-DC boost
converter and Inverter using Ziegler-Nicholz technique. The
performance of the system is analyzed under both variations
in temperature of PV cell and load parameter for the
feasibility of controller. Theoretical analysis and simulation
results are provided to verify its performance.
INTRODUCTION
One of the major issues confronting users and designers of
solar energy system is the random, fluctuating nature of
the energy sources. This makes them unpredictable’ are
even ‘unreliable’ in the eyes of some compared to
traditional supplies of electric energy. In reality, the load
on electric network supplied is itself random, being subject
to seasonal and environmental influences such as the
weather. All plant, whether, renewable or not, suffers from
occasional breakdown, which also impacts on supply
availability. This gives a basis of designing renewable
energy system – not on the basis of an unachievable 100%
reliability but to a availability The solar distributions were
used to obtain a net system availability using convolution
processes. This paper presents a different approach one
based on designing of PV cell, modeling of DC-DC boost
converter and Inverter. A PI controller is designed to
ensure regulation of system, under supply and load
disturbances.
PV CELL
Solar cells have many applications. They have long been
used in situations where electrical power from the grid is
unavailable, such as in remote area power systems, Earthorbiting
satellites and space probes, consumer systems,
e.g. handheld calculators or wrist watches, remote
radiotelephones and water pumping applications. More
recently, they are starting to be used in assemblies of solar
modules (photovoltaic arrays) connected to the electricity
grid through an inverter, often in combination with a net
metering arrangement.
CONCLUSION
This paper presents a PV Cell Stand alone model with
output voltage regulation. An 18V PV Cell, DC-DC Boost
converter and an Inverter are designed and results are
verified under closed loop operation . The purpose of DCDC
Boost Converter is to regulate the output voltage of
PV Cell. An inverter is used to convert DC to AC voltage
for application purposes. Two closed loop PI Controller is
effectively used to control entire system. The simulation
results verifies that output voltage of PV Cell and AC
voltage at the load is maintained constant under
temperature and load parameter variations. From the
performance analysis it can be concluded that an PV Cell
is effectively regulated with higher output voltage.