ABSTRACT:
In this work, a novel
technique based on adaptive filtering is proposed for the control of three
phase universal active power filter with a solar photovoltaic array integrated
at its DC bus. Two adaptive filters
along with a zero crossing detection technique, are used to extract the
magnitude of fundamental active component of distorted load currents, which is
then used in estimation of reference signal for the shunt active filter. This
technique enables extraction of active component of all three phases with
reduced mathematical computation. The series active filter control is based on
synchronous reference frame theory and it regulates load voltage and maintains
it in-phase with voltage at point of common coupling under conditions of voltage
sag and swell. The performance of the system is evaluated on an experimental
prototype in the laboratory under various dynamic conditions such as sag and
swell in voltage at point of common coupling, load unbalancing and change in
solar irradiation intensity.
KEYWORDS:
1. Power quality
2. Universal active power filter
3. Adaptive filtering
4. Photovoltaic system
5. Maximum power point tracking
6. Quadrature signal generation
SOFTWARE: MATLAB/SIMULINK
CIRCUIT DIAGRAM:
Fig. 1. System Configuration of Solar
Photovoltaic Integrated Unified Active
Power Filter
EXPERIMENTAL RESULTS:
Fig. 2. Salient Signals in Extraction
of Fundamental Positive Sequence Load
Current using Adaptive Filter
Fig.
3. Salient Signals in Series Active Filter Control
Fig. 4.
Steady State Per Phase Signals of PCC and Load Side in a PV-UAPF Compensated
System
Fig. 5.
PV-UAPF Response under Nominal Condition
Fig. 6.
PV-UAPF Response under Sag Condition
Fig. 7.
PV-UAPF Response under Swell Condition
Fig. 8.
PV-UAPF Response under Voltage Sag/Swell Condition at PCC
Fig. 9.
PV-UAPF Response under Load Unbalancing Condition
Fig. 10.
PV-UAPF Operation During Change in Solar Irradiation
CONCLUSION:
The performance of
adaptive filter based PV-UAPF system under both steady state and dynamic conditions,
have been analyzed in detail. The method of sampling the fundamental component
of load current obtained through adaptive filter enables fast extraction of
fundamental active component of nonlinear
load currents for all phases in one sampling. Only two adaptive filters are
required to extract magnitude of active component of three phase load currents.
This technique requires reduced computational resources while achieving good dynamic
and steady state performance in extraction of fundamental active component of
nonlinear load current. The system performance has been found to be
satisfactory under various disturbances in load current, PCC voltage and solar
irradiation. The series active filter is able to regulate load voltage at 220 V
under variations of PCC voltage from 170 V to 270 V. The grid current THD is maintained at approximately 3%
even though the THD of load current is
28% thus meeting requirement of IEEE-519 standard. The PV-UAPF system has been
able to maintain the grid currents balanced under unbalanced loading condition.
The
proposed topology and algorithm are suited for employing in conditions where
PCC voltage sags/swells and load current harmonics are major power quality
issues. Certain power quality issues not addressed include voltage distortions,
flicker, neutral current compensation etc. This power quality issues can be
addressed by modification of topology and control algorithm according to the
requirements in the distribution system.
The
PV-UAPF system provides dual benefit of distributed generation as well as
improving power quality of the distribution system.
[1] N. R. Tummuru,M. K. Mishra, and S.
Srinivas, “Dynamic energy management of hybrid energy storage system with
high-gain pv converter,” IEEE Transactions on Energy Conversion, vol.
30, no. 1, pp. 150–160, March 2015.
[2] B. Singh, A. Chandra, K. A. Haddad, Power
Quality: Problems and Mitigation Techniques. London: Wiley, 2015.
[3] S. Devassy and B. Singh, “Control of
solar photovoltaic integrated upqc operating in polluted utility conditions,” IET
Power Electronics, vol. 10, no. 12, pp. 1413–1421, Oct 2017.
[4] S. Devassy and B. Singh,
“Performance analysis of proportional resonant and adaline-based solar
photovoltaic-integrated unified active power filter,” IET Renewable Power
Generation, vol. 11, no. 11, pp. 1382– 1391, 2017.
[5] L. Ramya and J. Pratheebha, “A novel
control technique of solar farm inverter as pv-upfc for the enhancement of
transient stability in power grid,” in 2016
International Conference on Emerging Trends in Engineering, Technology and
Science (ICETETS), Feb 2016, pp. 1–7.
