The document presents a presentation on electric springs as a new smart grid technology. Electric springs function analogously to mechanical springs by providing voltage support, storing electric energy, and damping electric oscillations. They maintain the balance of power and demand on the grid through various compensation modes. The presentation outlines electric spring principles, types of compensation, operation and limitations. It provides results from practical evaluations showing electric springs can balance power and regulate voltage with intermittent renewable sources. Future applications include incorporating electric springs into smart loads to adapt to fluctuating renewable power.

1. A PRESENTATION ON
“Electric Spring- A New Smart Grid Technology”
SARVAJANIK COLLEGE OF ENGINEERING AND
TECHNOLOGY, SURAT
Prepared by: Amit A. Kulkarni
Enroll. No. : 150420707002
M.E-II Sem-IV
ELECTRICAL ENGINEERING DEPARTMENT
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2. Outline
 Introduction
 Principle & Realization of Electric Springs
 Types of Compensations
 Operations & Limitations
 Practical Evaluation
 Experimental Results
 Future of Work
 Conclusions
 References
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3. • The Paris Agreement
– To increase use of Renewable energy
• Intermittent power leads to new instability issues in power grid.
– Maintain instantaneous balance between power and demand.
• SMART LOAD and SMART GRID
• Centralized and Distributed systems for improving power quality
and controlling power flow.
Introduction
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Fig. 1 ES embedded in a SMART Load

4. • Described by Robert Hooke in 1678.
• Mechanical Spring:
– Provide mechanical support.
– Store mechanical energy.
– Damp mechanical oscillations.
• Hooke’s Law for Ideal mechanical spring;
History
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2
kx
2
1
P.E
-kxF


Fig. 2 An array of distributed mechanical spring

5. • Analogues to Mechanical spring an Electric spring
is an electric device that can be used to:
– Provide electric voltage support.
– Store electric energy.
– Damp electric oscillations.
• Hence electric spring can be controlled by the
charge stored in the capacitor.
Principle of ES
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a
a
Cvq
Cvq

 Inductive mode
Capacitive mode
 dtiq c

6. Analogy
1 2 3
1. Neutral Position
2. Mechanical Push
3. Mechanical Pull
1. Neutral Position
2. Voltage Boosting
Function
3. Voltage Reduction
Function
1. ES in form of C
2. Schematic for
i/p V control
3. ES with
dissipative load.
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Fig. 3 Different positions of ES

7. Types of Compensation
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Inductive Capacitive Positive Real Negative Real
Inductive
+
Positive Real
Inductive
+
Negative Real
Capacitor
+
Positive Real
Capacitor
+
Negative Real
Fig. 4 Vector illustration of three power quantities for different cases of power compensation

8. • Essentially involves dynamic control of an electric field in the capacitor.
• Varying the energy stored in electric field of the capacitor in a sinusoidal manner
with the objective of keeping the rms value of vs equal to vs_ref, an alternating
electromotive force (e.m.f.) with controllable magnitude at the mains frequency
can be generated across the capacitor as the electric spring voltage (va).
Operation
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Fig. 5 To ensure V & P at critical load to
remain constant when line voltage
feeding load is fluctuating.

9. • Aim is to restore Vs to nominal value of mains voltage Vs_ref.
• Pin-Dynamically changing input power.
• Power balance equation for system;
• Vector equation of Electric Spring is;
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Operation(Cont..)
   
21
2
2
2
1
2
1
ReRe
PPP
Z
Z
v
Z
Z
v
P
in
so
in














aso vvv 
21
2
21
22
PPP
R
v
R
vv
P
in
sas
in














 
 •Vs is kept constant by electric spring only variable is va.
•P2 is constant, so varying va will vary P1 ϶ sum of P1 &
P2 will follow profile of Pin.

10. • Considering R-L load, & vectors are rotating in
anticlockwise direction at grid frequency.
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Modes & Limitation
•ES is in “Neutral” position in which va=0.
•Power generation by renewable source is sufficient to meet the load
demand and simultaneously maintain vs at vs_ref.
•ES is in “Inductive” mode in which va is positive (+vc).
•Power reduction for Voltage boosting in Z1 needed in order to
keep vs at vs_ref.
•Vo is made less then vs_ref
•ES is in “Capacitive” mode in which va is negative (-vc).
•Power boosting for voltage reduction in Z1 needed in order to keep
vs at vs_ref.
•Vo is made less then vs_ref
Fig. 6 Operating mode of ES to maintain vs to vs_ref for R-L load

11. Neutral Inductive modeCapacitive mode
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Power System with ES
Fig. 7 Schematic of an Electric
Power System with an ES.
Fig. 8 Operating modes of ES to maintain vs at vs_ref for power system with source impedance of a network box.
Electric Spring

12. Case 1) Operation of an ES as a novel Smart-Grid device.
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Practical Evaluation
Fig. 9 Experimental setup for ES

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RESULTS
Fig. 10 Steady-state electric spring waveforms under “neutral” mode

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RESULTS(Cont..)
Fig. 11 Steady-state electric spring waveforms under “capacitive” mode.

15. RESULTS(Cont..)
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Fig. 12 Steady-state electric spring waveforms under “inductive” mode.

16. Case 2) Operation of an ES in unstable power grid fed
by intermittent Renewable Power.
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Fig. 14 RMS values of the mains voltage Vs , noncritical load voltage Vo and electric spring voltage Va before and after
the electric spring is activated.
RESULTS

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Fig. 15 Power of the critical load and noncritical loads.
RESULTS (Cont..)

19. Case 3) Test of ES in a power system with intermittent
Renewable Power injection.
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Fig. 16 ES tested in distribution network

20. RESULTS
Fig. 17 RMS values of the critical load (mains) voltage Vs, noncritical load load voltage Vo and electric spring voltage
Va before and after the electric spring is activated. 1
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21. 01-02-2018
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RESULTS (Cont...)
Fig. 18 Power of the critical load and smart load.

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Future Scope
Fig. 19 a)ES-2 b)Input voltage control c)Input current controller d)ES for PQ improvement e)PF correction by ES
a)
b)
c)
d)
e)

23. • SVC(SSSC) vs ES
• Provides both voltage support and suppression and for shaping load
demand to follow the fluctuating wind power profile.
• Can be incorporated with existing noncritical loads such as water heater,
road lighting systems to form a new generation of smart loads that are
adaptive to the power grid.
• Reliable and effective solution for distributed energy storage, voltage
regulation and damping functions for future power systems.
• Stability measures makes it independent of ICT.
• Unlike traditional ES provides RPC, with a cause to determined to de-
carbonize electric power generation to reduce global warming.
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Conclusions

24. • S. Yan, S. C. Tan, C. K. Lee, B. Chaudhuri and S. Y. R. Hui, "Use of
Smart Loads for Power quality Improvement," in IEEE Journal of
Emerging and Selected Topics in Power Electronics, vol. 5, no. 1, pp.
504-512, March 2017.
• S. C. Tan, C. K. Lee and S. Y. Hui, "General Steady-State Analysis and
Control Principle of Electric Springs With Active and Reactive Power
Compensations," in IEEE Transactions on Power Electronics, vol. 28, no.
8, pp. 3958-3969, Aug. 2013.
• S. Y. Hui, C. K. Lee and F. F. Wu, "Electric Springs—A New Smart Grid
Technology," in IEEE Transactions on Smart Grid, vol. 3, no. 3, pp.
1552-1561, Sept. 2012.
• N. R. Chaudhuri, C. K. Lee, B. Chaudhuri and S. Y. R. Hui, "Dynamic
Modeling of Electric Springs," in IEEE Transactions on Smart Grid, vol.
5, no. 5, pp. 2450-2458, Sept. 2014.
References
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