Real Power Modulation of a Wind Turbine Using Wide-Area ......• Sandia proprietary control system...
Transcript of Real Power Modulation of a Wind Turbine Using Wide-Area ......• Sandia proprietary control system...
Real Power Modulation of a Wind Turbine Using Wide-Area
PMU Feedback
Felipe Wilches-Bernal (SNL)Jon Berg (SNL)
David Schoenwald (SNL)Adam Summers (SNL)Brian Pierre (SNL)
Ian Gravagne (Baylor U.) & Ross Guttromson (SNL)with additional contributors:
Big Picture • Overall objective: Build a prototype, demonstration system that can
utilize spinning inertia (energy storage) of a wind turbine to “give and take” real power to grid
• In appropriate frequency band (approx 0.1 to 2 Hz)• Using PMU feedback in real time• Proportional to (but opposing) grid frequency deviations• DOE SBV between Sandia and NIRE (Lubbock, TX)
Big Picture Satellite Clock
PMU (SEL 487)
PMU(SEL 421)Satellite Clock
WSU network
WSU network
InternetInternet
UDPC37.118
SandiaDMZ
SNL XNetSNL XNet
CONET LabCONET Lab
θ2H(z)f2
UDPPacketBuild
ΣΣ
H(z)
fnom
θ1f1+
-
UDPPacket
Encryption
SNL XNetSNL XNet
Supervisory Control
InternetInternet
TTU networkTTU network
UDPPacket
Decryption
Wind ControlRoom
ΣΣ…
Modulated Torque
Command
Damping or RegulationSelector Switch
UDPC37.118
Ts
Ts
Ts
Ts
Ts
Δτ
Vestas V27 Wind Turbine
Visualizationand
Storage
Satellite Clock
Legendf1, f2: Grid frequencyCONET: Control and Optimization od Networked Energy TechnologiesSNL: Sandia National LaboratoriesSWiFT: Sandia Wind Test FacilityTs: GPS Time Stamp LocationTTU: Texas Tech Universityθ1 ,θ2 PMU Voltage Phase AngleWSU: Washington State UniversityXnet: Sandia Research Communication Network
τ
τ+Δτ
Turbine Controller
kΔf=Δτ…
SWiFT Site, Lubbock, TX Sandia CONET Lab, Albuquerque, NM
WSU, Pullman, WA
Network Switch
Turbine Controller
Modulation Controller
Background• Building on work of the Sandia/BPA PDCI modulation project
• B. Pierre et al., "Supervisory system for a wide area damping controller using PDCI modulation and real-time PMU feedback," 2016 IEEE Power and Energy Society General Meeting (PESGM), 2016.
• B. J. Pierre et al., "Open-loop testing results for the pacific DC intertie wide area damping controller," 2017 IEEE Manchester PowerTech, 2017.
• R. Guttromson, I. Gravagne, J. White, J. Berg, F. Wilches-Bernal, and C. Hansen, "SAND2018-772151: Use of Wind Turbine Kinetic Energy to Supply Transmission Level Services," Sandia National Laborotories, Albuquerque, NM, March, 2018.
• T. Knuppel, J. Nielen, K. Jensen, A. Dixon, J. Ostergard, “Power Oscillation Damping Controller for Wind Power Plant Utilizing Wind Turbine Inertia as Energy Storage,” 2011 IEEE Power and Energy Society General Meeting, 2011.
Experimental Setup: PMUs• PMUs
1. SEL 421 located at Washington State U (Pullman, WA), with GPS clock.2. SEL 487 Located at Sandia Labs, with GPS clock.
• Both PMUs transmitting C37.118-2015, “UDP_S”, 60 msg/s (WSU using public internet)
• Both on western grid
Experimental Setup: Modulation Controller• Modulation controller is the design prototype
for PDCI (resides at Sandia “CONET” lab)• LabView-based RT OS• Two operational modes
θ2H(z)f2
UDPPacketBuild
ΣΣ
H(z)
fnom
θ1f1+
-
UDPPacket
Encryption
Supervisory Control
Ts
Ts
𝑚𝑚𝑚𝑚𝑚𝑚 = 𝑘𝑘∆𝑓𝑓
Experimental Setup: SWiFT site• Scalable Wind Farm Technology site: 3 Sandia-owned Vestas V29
turbines in Lubbock. • 225 kW rated power• 29 m blade diameter• Retrofitted for Type IV operation (AC-DC-AC)• Sandia proprietary control system (NI VeriStand platform, with subsystems
compiled from MATLAB/Simulink)• Not on western grid but that’s OK
SWiFTControl House
Experimental Setup: Turbine Controller• Modified the turbine speed controller to accept “torque modulation”
input
Experimental Setup: Torque Modulator
Remove out-of-order packets
Incoming mod signal + origination time stamp
Safety checks
Error recovery
Bandpass
220 225 230 235 240 245 250 255 260
seconds
-25
-20
-15
-10
-5
0
5
10
15
20N
m, k
W
SWiFT Vestas turbine real power modulation: chirp test 3
700
720
740
760
780
800
820
840
860
880
RP
M
Torque Demand (Nm)
Real Power Output (kW)
Gen RPM
Chirp generatedat SWiFT
Chirp Test 1
550 555 560 565 570 575
Seconds
-20
-10
0
10
20
SWiFT Vestas turbine real power modulation: chirp test 4
12
14
16Torque Modulation (Nm)
Real Power Output (kW)
quantization ~.3 kW, 0.1 s
Chirp Test 2
400 450 500 550 600 650 700 750 800 850
Seconds
-20
-10
0
10
20SWiFT Vestas turbine real power modulation demonstration
0
5
10
15
20
Torque modulation (Nm)
Real Power Output (kW)
525 530 535 540 545 550
-20
-10
0
10
20Detail magnification
0
5
10
15
20
Wide area differential mode
0 0.5 1 1.5 2 2.5 3
Frequency (Hz)
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
Rel
ativ
e si
gnal
am
plitu
de
Stability control signal frequency content
Design bandwith
Tower resonance area
Wide area frequency content
220 230 240 250 260 270 280 290
Seconds
-2
0
2
4
6
8
10
12
14
16
SWiFT Vestas turbine real power modulation: regulation
5
10
Regulation Control Signal
Torque Modulation (Nm)
Real Power Output (KW)Frequency regulation modeSafety sat limit
Return-to-zero
Filters not allowing“slow” trends through
30 35 40 45 50
seconds
-15
-10
-5
0
5
10
SWiFT Vestas turbine real power modulation: signal latency
Control input signal
Torque Modulation (Nm) 39.5 40 40.5 41 41.5 42
-10
-5
0
5
10
Magnification Detail
40 - 65ms
Signal Latency
ℎ ℎ
1 2 3 5 4 6 7 9 8 10
𝜏𝜏𝐵𝐵
𝜏𝜏𝐴𝐴
𝜏𝜏𝐷𝐷𝜏𝜏𝑃𝑃
𝜇𝜇𝑃𝑃
𝜇𝜇𝑄𝑄
PMU sig transmission
PMU1 arrival
PMU2 arrival
Time alignment
Control sig transmission
Control sig arrival
Time alignment
0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.1
PMU transmission latency (s)
0
500
1000
1500
2000
2500
3000
3500
4000
4500PMU --> ABQ tranmission latency
PMU1 (Albuquerque)
mean = 27 ms
std = 1.3 ms
N = 16700
1 outlier at 93 ms
PMU1 (Washington State)
mean = 70 ms
std = 1.3 ms
N = 16700
PMU transmission delay
0.037 0.0375 0.038 0.0385 0.039 0.0395 0.04 0.0405
seconds
0
10
20
30
40
50
60
70
80
90
100ABQ --> SWiFT network transmission latency histogram
mean = 38.4 ms
std = 0.56 ms
N = 4987 Control signal transmission delay
Q: How’d you get transmissions in/out of Sandia so quickly? A: X-net
A word on comm security• Message Authentication Coding (MAC) using SHA-256 w/ pre-share
key
Illustration of Message Authentication Code Process (www.sqa.org.uk)
ABQ SWiFT
Conclusions, future work• It is possible to modulate the real power output of a wind turbine with zero
“spill” using real-time PMU feedback. • Wind operators can provide grid services (“Wind helps grid!”)• Within appropriate frequency band
• Challenges remain:• Need better measurement of power output (PMU at tower)• Analysis of overall phase margin complicated (filters, delays, sampling,
quantization...)• Freq regulation mode needs more thinking• Explore larger (much larger?) modulation limits• Can it be scaled up? • Ongoing question of cybersecurity for PMU comm