IEEE Transactions on Sustainable Energy, 2017
ABSTRACT: This paper proposes a novel double-fed induction
generator (DFIG)-based wind-energy conversion system (WECS), which incorporates
a dynamic voltage restorer (DVR) and energy storage system (ESS). The DVR is in
series with the output terminal of a wind turbine generator (WTG) and parallel
to the dc link of the WTG with the ESS. The control scheme of the WECS is
designed to suppress wind power fluctuations and compensate grid voltage
disturbances, which in turn improve the fault ride through (FRT) capability and
the wind power penetration level. Finally, the performance of this WECS is
investigated under various operation scenarios such as symmetrical and
asymmetrical grid faults.
KEYWORDS:
1. Double-fed induction generator (DFIG)
2. Energy storage system (ESS)
3. Wind power fluctuations
4. Dynamic Voltage Restorer (DVR)
5. Fault Ride Through (FRT).
SOFTWARE:
MATLAB/SIMULINK
BLOCK DIAGRAM:
Fig. 1. Structure of the novel
DVR-ESS-embedded WECS
EXPECTED EXPERIMENTAL
RESULTS:
Fig. 2. Symmetrical grid fault with 50%
voltage dip. (a) Grid voltage. (b) Compensation voltage. (c) WTG’s terminal
voltage. (d) RSC/GSC current RMS. (e) Power response. (f) Additional power
response. (g) State of charge. (h) DC link voltage.
Fig. 3. Symmetrical grid fault with 90%
voltage dip. (a) Grid voltage. (b) Compensation voltage. (c) WTG’s terminal
voltage. (d) RSC/GSC current RMS. (e) Power response. (f) Additional power
response. (g) State of charge. (h) DC link voltage.
Fig. 4. System performance under asymmetrical
grid fault. (a) Grid voltage. (b) Compensation voltage. (c) WTG’s terminal
voltage. (d) RSC/GSC current RMS. (e) Power response. (f) Additional power
response. (g) State of charge. (h) DC link voltage.
Fig. 5. Different sequence components in
d-q reference frame. (a) Positive-sequence components in d-axis.
(b) Positive-sequence components in q-axis. (c) Negative-sequence
components in d-axis. (d) Negative-sequence components in q-axis
Fig.6 Crowbar scheme
Fig.7 WECS scheme
CONCLUSION:
In this paper, a novel
DVR-ESS-embedded WECS is proposed. The system configuration and its control
scheme are designed, and simulations are conducted under normal operation and
fault operation conditions to test the system performance. The main conclusions
are as follows. The embedded ESS can store surplus wind power for release when
needed. By designing different power output commands, i.e., constant output
power or filtered output power, the ESS can effectively suppress the wind power
fluctuations and further improve the penetration level of wind power. The use
of a DVR can significantly improve the FRT capability of the WECS under
symmetrical and asymmetrical voltage fault conditions, and is particularly
suitable for already installed DFIG-WTGs that do not possess sufficient FRT
capability. During a disturbance, the blocked wind power generation is stored
for subsequent use to suppress wind power fluctuations without any loss of
energy.
REFERENCES:
[1]
T. Ackermann, “Wind Power in Power Systems,” 2nd
ed., Chichester: Wiley-Blackwell, 2012.
[2]
International Electrotechnical Commission, “Grid
integration of large capacity renewable energy sources and use of large
capacity electrical energy storage,” White paper, 2012.
[3]
A. McDonald and G. Jimmy, “Parallel wind turbine
powertrains and their design for high availability,” IEEE Trans. Sustain.
Energy, vol. 8, no. 2, pp. 880-890, Apr. 2017.
[4]
J. Yao, H. Li, Z. Chen, X, Xia, X, Chen, Q, Li,
and Y, Liao, “Enhanced control of a DFIG-based wind-power generation system
with series grid-side converter under unbalanced grid voltage conditions,” IEEE
Trans. Power Electron., vol. 28, no.7, pp. 3167-3181, Jul. 2013.
