Power electronic devices have become abundant today due to their capabilities
for precise process control and energy savings benefits. However, they also ...
Mehran University of Engineering & Technology, Jamshoro. Submitted in ... We are also very thankful to our co-supervisor, Engr. Ms Mokhi Maan, assistant.
power compensation capacitors and passive filters, and they are single-phase equipment installed in each feeder of the traction substation. Usually, the coupling ...
GRID. PRoduCt guide. Why do we need reactive power compensation and
harmonic filtering? ..... mV switchgear and motor control centers. • large
transformers.
quantify the benefit for the electric utility company and users in the reactive power compensation problem. Then we derive the optimal solution for the active and ...
employed DSP offers several assembly language instructions optimizing ... The prototype consists of an intelligent power supply Agilent 6813B AC Power ...
HARMONIC FILTERING AND REACTIVE POWER COMPENSATION. ..... ordered
I design main and control circuits as well as equipment layout. As a last steps, ...
equipments are well known as Flexible AC Transmission Systems (FACTS) devices, and introduced in 1988 by Hingorani [3]. The objective of FACTS devices is ...
The function of an AC transmission system is to provide electric power from one ... AC voltage than FACTs device, the reactive power from a. STATCOM ..... Flexible AC Transmission Systems,â IEE Proceedings on Generation,. Transmission ...
The Static Synchronous Compensator (StatCom), and Static VAR Compensator (SVC) are twotypes of shunt controllers for injection of reactive current, their.
are with Power Electrical and Electronic Systems Research Group,. University of Extremadura, School of Industrial Engineering, Avda. Elvas s/n 06006 Badajoz, ...
mechanics - the problem of QRHO under Brownian motion. ...... other researchers associated this phenomena with nonclear and exotic nature of nucleus.
Jan 23, 2012 - ... locations and adequate amount of reactive power support at HV/MV transformer station is also required. ..... List of Figures. Figure 1.1 Basic ...
FACTS consist of SVC, Thyristor switched capacitors, Thyristor controlled reactor, .... thyristor (GCT) has an improved gate structure and gate-drive circuitry.
Feb 21, 2015 - that demanded. In distribution system, these generated ... Email Id: [email protected] ... functionality of the power distribution system.
Reference List. This reference list gives an overview of Siemens' reactive power
compensation and power quality management projects for utility applications.
Feb 21, 2015 - [7] L. M. Cipcigan and P. C. Taylor, âInvestigation of the reverse ... [23] M. Fila, G. A. Taylor, M. R. Irving, J. His cock, P. Lang, and P. Aston,.
modular features of an H-bridge based multilevel STATCOM. This approach allows the implementation of the topology with dedicated modules in order to ...
Apr 1, 2017 - Distributed Energy Micro-Storage Systems in Smart. Communities ... Introduction. The idea of the so called Smart Communities [1,2] is supported by the following facts: the rising ... their own renewable energy supply. A central ...
34. NONLINEAR LOAD REACTIVE COMPENSATION AND POWER FACTOR CORRECTION USING. MODULATED POWER FILTER. A.M.Sharaf and H.Huang.
May 13, 2010 - dc-link capacitor and the battery. Index Terms-Battery, bidirectional charger, charger, electric vehicle, EV, PHEV, reactive power, V2G.
Olcay Aydin, Lecturer. Department of Control and Automation Technologies,. Turgutlu Vocational School, Celal Bayar University,. Turgutlu/Manisa/Turkey.
May 30, 2012 - Publisher's Note: âMagnetic diagnostics using the third-harmonic magnetic response for a molecule-based magnet networked by a single chiral ...
Video Super-Resolution Using Motion Compensation and. Classification-Aided Fusion. Karen Simonyan*, Sergey Grishinâ ,. Moscow State University, Graphics ...
... power theories. ⣠Experimental verification of shunt compensation. Photo: http://fc08.deviantart.net/fs70/f/2011/146/1/d/europe_by_bang_a_rang-d3ha2gk.jpg.
Reactive and Harmonic Compensation Using the Conservative Power Theory Thomas Haugan and Elisabetta Tedeschi
Presentation Outline !
• • • •
Smart grid and active power filtering The conservative power theory Experimental verification Conclusion
The Smart Grid Concept !
• !
•
• !
The traditional power system! ‣ Symmetric and sinusoidal grid voltage ‣ Well established power theories The smart grid! ‣ Increasing energy demand ‣ Environmental and climatic issues ‣ Sustainable energy mix (renewables) ‣ Distributed generation ‣ Electric vechicles ‣ Grand-scale introduction of power electronic loads ‣ Update power theories ‣ Counteract unbalanced and non-sinusoidal load scenarios
FACTS - Shunt compensation! ‣ Passive compensators ‣ Active compensators, active power filters (APF) Active power filtering! ‣ Power electronics converter in current control mode ‣ Eliminate load current distortion ‣ Power factor correction ‣ Load balancing ‣ Reference generator algorithm dictates APF characteristics ‣ Performance closely related to latency in digital controller 4
Conservative Power Theory (CPT)
p(t) = u(t) i (t) = _
q(t) = u(t) i (t) =
N X
n=1 N X
un (t)· in (t) dt _
u n (t)· in (t) dt
n=1
_
s(t) = p(t) + jq(t) = u(t) i (t) + j u(t) i (t)
5
CPT - Basic Currents i a (t) =
N {ian }n=1
i r (t) =
,
N {irn }n=1 N
i v (t) = {ivn }n=1 ,
ian (t) = ,
irn (t) =
Pn un
2 un
Qn _
un
ivn (t) = in (t)
= Gn u n
_
2
_
u n = Bn u n
ian (t)
irn (t)
6
CPT - Balanced Currents
i ba (t)
i br (t)
=
N b ian n=1
=
N b irn n=1
,
iban (t)
,
ibrn (t)
=
=
P u
b u = G un 2 n
Q _
u
_
2
b_
un = B un
7
CPT - Unbalanced Currents
i ua (t) = i a (t)
i ur (t) = i r (t)
n
i ba (t) = (Gn n
i br (t) = (Bn
Gb )un
_
oN
Bb)un
n=1
oN
n=1
8
CPT - Decomposition of Current i (t) = i b (t) + i u (t) + i v (t) = i ba (t) + i ua (t) + i br (t) + i ur (t) + i v (t) i (t)
2
= i b (t)
2
+ i u (t)
2
+ i v (t)
2
= i ba (t)
2
+ i ua (t)
2
+ i br (t)
2
+ i ur (t)
2
+ i v (t)
2
Measured Current i(t)
Balanced Active Currents iba (t)
Unbalanced Active Currents iua (t)
Balanced Reactive Currents ibr (t)
Unbalanced Reactive Currents iur (t)
Void Currents iv (t)
9
CPT - Decomposition of Power 2
A = u
2
i
2
= u
2
·
⇣
2 i ba
+
2 i ua
+
2 i br
+
2 i ur
+ iv
2
⌘
= P 2 + Na2 + Q2 + Nq2 + D2
Apparent Power A
Active Power P
Reactive Power Q
Unbalanced Active Power Na
Unbalanced Reactive Power Nq
Distortion Power D
10
CPT - Decomposition of Current Void Currents
• • •
Residual component after considering balanced/unbalanced currents. Account for harmonics in the current. Correspond to distortion power and instantaneous power oscillations.
! Unabalanced Reactive Currents • • •
Equal any difference between basic and balanced reactive currents. Account for zero and negative sequence currents, system unbalance. Correspond to unbalanced reactive power.
! Balanced Reactive Currents • • •
Calculated assuming a symmetric power system. Quadrature phase-relation with system voltages. Correspond to reactive power.
! Unbalanced Active Currents • • •
Equal any difference between basic and balanced active currents. Account for zero and negative sequence currents, system unbalance. Correspond to unbalanced active power.
! Balanced Active Currents • • •
Calculated assuming a symmetric power system. Phase-aligned with system voltages. Correspond to active power.
Measured Load Current
i (t) = i b (t) + i u (t) + i v (t) = i ba (t) + i ua (t) + i br (t) + i ur (t) + i v (t) i (t)
2
= i b (t)
2
+ i u (t)
2
+ i v (t)
2
= i ba (t)
2
+ i ua (t)
2
+ i br (t)
2
+ i ur (t)
2
+ i v (t)
2 11
CPT - Summary !
Void Currents
•
Main Properties! ‣ Valid in both symmetric sinusoidal and harmonic voltage regimes ‣ Accounts for unbalance and ‣ harmonic load characteristics ‣ The classic power theory is included as a subset ‣ Orthogonal mapping of current and power flow
Unabalanced Reactive Currents
Balanced Reactive Currents
!
•
Current Decomposition! ‣ Balanced active currents ‣ Balanced reactive currents ‣ Unbalanced active currents ‣ Unbalanced reactive currents ‣ Void currents
Unbalanced Active Currents
!
•
Power Decomposition! ‣ Active power ‣ Reactive power ‣ Unbalanced active power ‣ Unbalanced reactive power ‣ Distortion power
Balanced Active Currents
Measured Load Current
! i (t) 2
2
= i b (t)
A = u
2
i
2
2
+ i u (t)
= u
2
·
⇣
2
2
= i ba (t)
2 i ua
2 i br
+ i v (t)
2 i ba
+
+
2
+
+ i ua (t) 2 i ur
2
+ i br (t)
+ iv
2
⌘
2
+ i ur (t)
2
+ i v (t)
2
= P 2 + Na2 + Q2 + Nq2 + D2
12
Harmonic filtering
Reactive compensation
Load balancing
Active Power Filtering
CPT! Applications
Instrumentation & Measurement Power metering
Power system monitoring
Accountability
13
Prestudy - Simulation in Simulink
• • • •
Load: three-phase thyristor rectifier on stiff grid Cause harmonic pollution and reactive power consumption Active power filter eliminates harmonics and Q Idealistic representation, latency in digital signal processor
Active Power Filter - Controller! ‣ LEM current/voltage transducers ‣ Xilinx ML605 FPGA ‣ OPAL-RT OP5600 Real-Time Simulator ‣ Model-based code (C++/VHDL) generation Active Power Filter - Hardware! ‣ 20 kW 3-phase/2-level VSC ‣ 2.0 mH L-filter between grid and VSC Tested 3 Common Scenarios! ‣ Stiff grid voltage 3ph 230V/50Hz ‣ A Diode rectifier ‣ B Thyristor rectifier ‣ C Diode rectifier in parallel w/RL-load
15
Test A - Diode Rectifier Fluke 434 (Grid)
CPT (Load)
• • • •
Target: remove current harmonics. Improved harmonic spectrum. Notable reduction in THD. Residual current harmonics.
16
Test B - Thyristor Rectifier Fluke 434 (Grid)
CPT (Load)
• • • •
Target: provide harmonic filtering and reactive power compensation. Greatly improved power factor. Reduction of THD and harmonic content. Uncompensated high-order harmonics due to APF controller latency. 17
Test C - Diode Rectifier and RL-Load Fluke 434 (Grid)
CPT (Load)
• • • •
Target: harmonic filtering and reactive power compensation. Unity power factor. Dominant harmonics eliminated. Residual switching ripple from APF.
18
Conclusion • Trend: grand-scale introduction of power electronic loads • Electric vehicles and associated super-chargers • Possible issues: system stability, harmonic pollution, low power factor and reduced transmission capacity. • APF can be utilized to compensate harmonics, reactive power. • The CPT aims to more accurately decompose current and power flow for all voltage regimes. • CPT applications: instrumentation and shunt compensation. • Experimental demonstration that CPT and APF can be used to deal with harmonics and power factor correction.
