CCS355 Neural Networks & Deep Learning Unit 1 PDF notes with Question bank .pdf
Adaptive Frequency PLL Approach for Grid Connected MFI
1. An Adaptive Frequency PLLApproach for
Grid Connected Multifunctional Inverter
for Residential Applications
Presented By:
Mrs. A. Mounika Reddy
Research Scholar, Annamalai University
Paper Id: PSM 3059
The 2nd International Conference
on Advances in Physical Sciences and Materials 2021
(ICAPSM 2021)
12-13 Aug 2021,Coimbatore,India
2. Abstract
• In this paper, an adaptive frequency Phase locked loop (PLL) based approach for grid
connected multifunctional inverter is presented for residential applications.
• The proposed approach deals with non-linear loads and also non ideal grid voltages
like unbalance harmonics, frequency variation, magnitude variation, etc. and can
eliminate the DC offset in a voltage signal which in turn improves the power quality.
• A third order generalized integrator based PLL with adaptive frequency and DC offset
elimination blocks will effectively deal with the power grid voltage changes, frequency
changes and eliminate the phase difference between PLL output.
• This approach is implemented as control algorithm for single-stage single-phase grid
connected multifunctional inverter for PV applications in order to feed energy to the
grid and also to improve the power quality.
3. • Perturb & Observe based Maximum Power Point Tracking method is
employed for estimating reference PV voltage signal and power. A
detailed analysis with the proposed control technique is presented in
this paper.
• Various operating conditions are provided to verify the performance
and effectiveness of the proposed control using MATLAB / Simulink.
4. Power Quality
Causes for Power Quality Problems
• Unbalanced Load for a Three-Phase System
• Switching of Heavy Loads.
• Lightening
• Non-Linear Loads.
Techniques to Mitigate Power Quality Problems
• Passive Filter Techniques
A Combination of L & C Passive elements for Filtering.
• Active Power Filter Techniques
Using VSI and CSI
•Hybrid Filter Techniques
A Combination of Passive and Active Filters.
The term Power Quality describes the variation of voltage, current, frequency and
Harmonics in the power system.
5. • Synchronization means
the minimization of
difference in voltage,
frequency and phase angle
between the corresponding
phases of the generator
output and grid supply.
• Grid synchronization is
an important part in the
control of grid-connected
power electronic
converters. The
fundamental phase-angle
at the point of common
coupling should be tracked
on-line in order to control
energy transfers
6. Line Diagram of Single-Stage PV Grid
Connected System
β
v
+
-
pv
v
S S
1 4
dc
C
pv
i
inj
i
f
L
s
L s
R
L
i
l
L
ldc
R
ldc
L
t
v
s
v
Non Linear Load
A A
A
A
7. Basic PLL
Third Order Generalized Integrator with
adaptive frequency unit based QSG
DC elimination unit
Kdc
Orthogonal Signal Generation unit
Frequency estimation
unit
Kf
K
α
v
t
v
β
v
8. The proposed TOGI Based Phase
Locked Loop
TOGI
t
v
α
v
β
v
α β
d q
v v
2 2
d
v
Mod
2p
Sin t
p
V̂
t
Sin
𝒘𝒇𝒇
c
10. Performance of Proposed MFI with
Non-Linear Load
Performance of the proposed MFI with
nonlinear load
Operation of the grid under Voltage Swell
(15%)
11. Dynamic Performance of the
controller when a sudden load is
applied.
Performance of MFI with change in
irradiance from 1000 to 800 W/m2.
12. Performance of MFI with change in
irradiance from 800 to 600 W/m2.
Performance of MFI with change in
irradiance from 600 to 1000 W/m2.
13. Performance of MFI when
temperature is changed from 250 C
to 350 C.
Performance of MFI when
temperature is changed from 350 to
300 C.
14. Conclusion
A simple controller based on frequency adaptive approach for a single-phase
single-stage grid connected multifunctional inverter is proposed and tested using
MATLAB / Simulink. The proposed controller proves its tracking ability of the grid
voltage or load current signal under adverse conditions and sudden load changes. The
solar PV system is integrated with the grid in such a way to feed the load and also to
the grid during off load conditions. The controller is tested during change in
temperatures and irradiance, voltage swell, non-linear load conditions and sudden
changes in load. In all these conditions, the tracking of peak load current and voltage
magnitude and phase are found to be satisfactory.
