Power Quality Improvement
Using UPQC Integrated with Distributed Generation Network
ABSTRACT
The increasing demand of electric
power is giving an emphasis on the need for the maximum utilization of
renewable energy sources. On the other hand maintaining power quality to satisfaction
of utility is an essential requirement. In this paper the design aspects of a
Unified Power Quality Conditioner integrated with photovoltaic system in a distributed
generation is presented. The proposed system consist of series inverter, shunt
inverter are connected back to back on the dc side and share a common dc-link capacitor
with Distributed Generation through a boost converter. The primary task of UPQC
is to minimize grid voltage and load current disturbances along with reactive
and harmonic power compensation. In addition to primary tasks of UPQC, other
functionalities such as compensation of voltage interruption and active power
transfer to the load and grid in both islanding and interconnected mode have
been addressed. The simulation model is design in MATLAB/ Simulation environment
and the results are in good agreement with the published work.
KEYWORDS:
1. Distributed Generation(DG)
2. Interconnected mode
3. Islanding mode
4. Maximum power point tracking (MPPT)
5. Power Quality (PQ)
6. Unified power quality conditioner
(UPQC)
7. Photovoltaic array (PV).
SOFTWARE:
MATLAB/SIMULINK
BLOCK
DIAGRAM:
Fig. 1. UPQC with
DG connected to the DC link
Fig. 2 Bus voltage,
series compensating voltage, and load voltage
Fig. 3 Simulation result for
upstream fault on feeder: Bus voltage, compensating voltage, load voltage
Fig. 4 Simulation results for load
change: nonlinear load current,Feeder current, load voltage, and dc-link
capacitor voltage
CONCLUSION
The new configuration is named
unified power-quality conditioner with Photo Voltaic System (UPQC-PV). Compared
to a conventional UPQC, the proposed topology is capable of fully protecting
critical and sensitive loads against distortions, sags/swell, and interruption
in both islanding and interconnected modes. The performance of the UPQC-PV is evaluated
under various disturbance conditions and it offers the following advantages:
1) To regulate the load voltage
against sag/swell and disturbances in the system to protect the
nonlinear/sensitive load.
2) To compensate for the reactive
and harmonic components of nonlinear load current.
3) To compensate voltage
interruption and active power transfer to the load and grid in islanding mode
to protect sensitive critical load.
4) Depending upon the ratings, the
combined system can reduce the cost up to one fifth of the separate system. Capacity
enhancement has been achieved using multi-level or multi-module and central
control mode, however, the flexibility of UPQC to increase its capacity in
future and to cope up with the increase load demand in medium voltage distribution
system.
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