ABSTRACT:
Renewable energy sources;
which are abundant in nature and climate friendly are the only preferable
choice of the world to provide green energy. The limitation of most renewable
energy sources specifically wind and solar PV is its intermittent nature which
are depend on wind speed and solar irradiance respectively and this leads to
power fluctuations. To compensate and protect sensitive loads from being
affected by the power distribution side fluctuations and faults, dynamic
voltage restorer (DVR) is commonly used. This research work attempts to
withstand and secure the effect of voltage fluctuation of grid connected hybrid
PV-wind power system. To do so battery and super magnetic energy storage (SMES)
based DVR is used as a compensating device in case of voltage sag condition.
The compensation method used is a pre-sag compensation which locks the
instantaneous real time three phase voltage magnitude and angle in normal
condition at the point of common coupling (PCC) and stores independently so
that during a disturbance it used for compensation. Symmetrical and
asymmetrical voltage sags scenario are considered and compensation is carried
out using Power System Computer Aided Design or Electro Magnetic Transient
Design and Control (PSCAD/EMTDC) software.
KEYWORDS:
1.
Dynamic voltage restorer
(DVR)
2.
Energy storage
3.
Intermittent
4.
Power quality
5.
Voltage sag compensation
SOFTWARE: MATLAB/SIMULINK
Figure 1. The Proposed Bes-Smes Based Dvr For On Grid Pv-Wind Hybrid System
EXPERIMENTAL RESULTS:
(a)
(b)
(c)
Figure 2. Simulation Results And Dvr Response For
25% Symmetrical Voltage Sag Case (A) Load Voltage Without Dvr, (B) Dvr Injected
Voltage And (C) Load Voltage With Dvr
(a)
(b)
(c)
Figure 3. Simulation Results And Dvr Response For 12%
Symmetrical Voltage Sag Case (A) Load Voltage Without Dvr, (B) Dvr Injected
Voltage And (C) Load Voltage With Dvr
(a)
(b)
(c)
Figure 4. Simulation Results And Dvr Response For
25% Asymmetrical Voltage Sag Case (A) Load Voltage Without Dvr, (B) Dvr
Injected Voltage And (C) Load Voltage With Dvr
(b)
(c)
Figure5. Simulation Results And Dvr Response For 35%
Asymmetrical Voltage Sag Case (A) Load Voltage Without Dvr, (B) Dvr Injected
Voltage And (C) Load Voltage With Dvr
In this paper, a voltage sag enhancement
of sensitive load which gets power from grid connected PV-wind power system is
demonstrated using HES based DVR. The proposed DVR targets to protect the
sensitive load from being affected by any voltage fluctuation which arise
either from fault condition or unstable power output of PV-wind system. The
control and operations of BES and SMES devices is developed by observing
voltage condition of the grid at the PCC and the SOC levels of battery and
SMES. In addition to this, for full realization of the proposed DVR system the
control and operation of the VSC is developed by observing the voltage level at
the PCC. The pre-sag compensation strategy is selected based on the capability
of both magnitude and phase jump restoration. Based on the conditions, three
operating states of the HES based DVR are defined, which are normal (idle
state), charging state and discharging state. The effectiveness of the proposed
operating states has been demonstrated in realistic cases. In the simulation,
different voltage sag depth scenarios are considered for both symmetrical and
asymmetrical voltage imbalances and the HES based DVR works well. A combination
of voltage sag, voltage swell and harmonics scenarios will be demonstrated in
the future works.
REFERENCES:
[1] BP Statistical Review of World
Energy, 68th ed. 2019.
[2] M. R. Banaei and S. H. Hosseini,
“Verification of a new energy control strategy for dynamic voltage restorer by
simulation,” vol. 14, pp. 112–125, 2006.
[3] IRENA, Future of wind: Deployment,
investment, technology, grid integration and socio-economic aspects (A Global
Energy Transformation paper). International Renewable Energy Agency, Abu Dhabi,
2019.
[4] IRENA, Future of Solar Photovoltaic:
Deployment, investment, technology, grid integration and socio-economic aspects
(A Global Energy Transformation: paper). International Renewable Energy Agency,
Abu Dhabi, 2019.
[5] H. M. Al-masri, S. Member, M.
Ehsani, and L. Fellow, “Feasibility Investigation of a Hybrid On-Grid Wind
Photovoltaic Retrofitting System,” IEEE Trans. Ind. Appl., vol. 52, no. 3, pp.
1979–1988, 2016.
