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
BLOCK DIAGRAM:
FIGURE 1. On grid PV-wind hybrid system
EXPECTED SIMULATION 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
(a)
(c)
FIGURE 5.
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
CONCLUSION:
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 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.
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