MODELING OF HVDC-MMC TRANSMISSION SYSTEM FOR ELECTROMAGNETIC TRANSIENTS June 21st 2013 Hani SAAD Ph.D. student Director: Prof. J. Mahseredjian, École Polytechnique de Montréal, Canada Co-director: Prof. X. Guillaud, École Centrale de Lille, France Industrial partner : RTE-France Co-directors of project: S. Nguefeu and S. Dennetière
24
Embed
MODELING OF HVDC-MMC TRANSMISSION SYSTEM FOR ... · 2. MMC topology overview 3. MMC models 4. Control system 5. HVDC-MMC model in EMTP-RV 2 Here is the plan of the presentation. I
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
MODELING OF HVDC-MMC TRANSMISSION SYSTEM FOR ELECTROMAGNETIC TRANSIENTS
June 21st 2013
Hani SAAD
Ph.D. student
Director: Prof. J. Mahseredjian, École Polytechnique de Montréal, Canada
Co-director: Prof. X. Guillaud, École Centrale de Lille, France
Industrial partner : RTE-France
Co-directors of project: S. Nguefeu and S. Dennetière
Hello everybody, my name is Hani saad I am a phd student from the ecole polytechnique de montreal And my presentation focuses on modeling hvdc-mmc System for electromagnetic transients
Plan:
1. Introduction
2. MMC topology overview
3. MMC models
4. Control system
5. HVDC-MMC model in EMTP-RV
2
Here is the plan of the presentation. I will first start witht a small introduction, than show overview of the MMC topology. After that, the differents type of models developped in emtp are presented. The control system strucuture is than presented, and the HVDC-MMC system model in emtp is than simulated and presented
1. Introduction
3
VSC based HVDC transmission system is expanding rapidly.
The recent Modular Multilevel Converter (MMC) topology offers significant benefit compared to previous VSC technologies
Advantages of Modular Multilevel Converter (MMC):
• Low frequency modulation
• Lower transient peak voltages on IGBT, which will lead to a lower losses
• Very low THD, hence no need for High-pass filters or very small size
• Modular structure, scalable to different power and voltage levels
As may everybody know, Vsc-hvdc link are expanding rapidly due to several reasons as enviromental, decreasing cost of the power switchs, the ability to supply weak grid etc. The recent VSC type topology called MMC offers significant advantages compared to other previous topology as 2-3levels
2. MMC topology overview
4
Idc
SM-1
SM-2
SM-N
SM-1
SM-2
SM-N
SM-1
SM-2
SM-N
SM-1
SM-2
SM-N
SM-1
SM-2
SM-N
SM-1
SM-2
SM-N
Vdc
Ls
Ls Ls Ls
Ls Ls
iua
ib
ic
va
iub iuc
ila ilb ilc
vb ia
vc
. . . . . . . .
.
. . . . . . . .
.
Arm At normal operation, S1 and S2 are complementary The sub-module consist of two states: Su->on and Sl->off Su->off and Sl->on
SM
aupv _
SM
alowv _
Sub-Module
C
Su
Sl
Su
Sl
On
On
On
On
Off
Off
Off
Off
ON State OFF State
On Off
Su
Sl
Su
Sl
Su
Sl
3. MMC models
5
Depending on the type of study different type of modeling are presented:
• Model 1 – Model based on nonlinear IGBT models
• Model 2 – Model based on simplified switchable resistance
• Model 3 – Switching Function of Arm (SF-arm)
• Model 4 – Average Value Model of MMC (AVM-MMC)
. .
. . . .
Model 4 Model 3 Model 2 Model 1
3. MMC models
6
Model 1 - Models based on nonlinear IGBT models
• In this case IGBT/diode are modeled by nonlinear resistor and an ideal switch.
p
n
g
C
g
p
n
S1
S2K2K1
+
RL
C
g
p
n
0 1000 2000 3000 4000
0.6
0.8
1
Current (A)
Voltage (
V)
Entered characteristic plot
Advantages: Very easy to achieve, it preserve the main structure of the IGBT The V-I curve of the IGBT/diode is modeled.
Total IGBT/diode in the HVDC-MMC 401 Level system: 2(IGBT/SM)*400(SM/arms)*2(arms/phase)*3(phases)*2(converters) = 9 500 IGBTs/diodes
i(t)
iua
i(t)
ila
+L_
arm
1
#L
arm
#
+L_
arm
4
#L
arm
#
i_arm_pu i_arm_A
Base i_arm
i_arm_pu i_arm_A
Base i_arm
S Vc
pos
ph
400 SM
400SM _low_A
S Vc
pos
ph
400 SM
400SM _up_A
Vc _up_AS_up_A
S_low_AVc _low_A
AC
i_up_A
P
N
i_ low_Bi_ low_A
i(t)
iub
i(t)
iuc
i(t)
ilb
i(t)
ilc
+L_
arm
2
#L
arm
#
+L_
arm
3
#L
arm
#
i_arm_pu i_arm_A
Base i_armi_arm_pu i_arm_A
Base i_arm
i_arm_pu i_arm_A
Base i_arm
i_arm_pu i_arm_A
Base i_arm
+L_
arm
5
#L
arm
#
+L_
arm
6
#L
arm
#
S Vc
pos
ph
400 SM
400SM _up_B
S Vc
pos
ph
400 SM
400SM _up_C
S Vc
pos
ph
400 SM
400SM _low_B
S Vc
pos
ph
400 SM
400SM _low_C
Vc _up_BS_up_BS_up_C Vc _up_C
S_low_BVc _low_B
S_low_CVc _low_C
i_up_Bi_up_C
i_ low_C
c
b
a
AC
i_up_A
P
N
i_ low_Bi_ low_A
i_up_Bi_up_C
i_ low_C
3. MMC models
D
S
G
+
+R
LC
+
1M
nonlinear diode model
+
0 R
n1
p1p2
V1
V0
S2
+
#Cp#
!v
Cp
S1
Rc
Vc_eq2
Rc
Vc_eq400
Rc
Vc_eq1
r1_1
r2_1
r1_2
r2_2
r2_400
r1_400
veq
varm
iarm
req
Advantages: Reduction of electrical nodes to 3 nodes, without loosing the variable information of each SM. Low computation time Inconvenient: The model is hard-coded, hence the user has no more access to SM circuits The V-I curve of IGBT/diode is not modeled
C vc_1
C vc_2
vc_400 C
_ _ _ _
1 1
( ) ( ) . ( ) ( )N N
arm SM eq i arm SM eq i
i i
v t r t i t v t T
_
_ _
2( ). 1( )( )
2( ) 1( ) )
2( )( ) ( ).
2( ) 1( )
c
SM eq
c
SM eq c eq
c
r t r t Rr t
r t r t R
r tv t T v t T
r t r t R
3. MMC models
8
Model 2 - Models based on simplified switchable resistance IGBT and diodes are represented by two-value resistors (Ron and Roff). A reduction is performed to reduce the number of electrical nodes that describe converter.
Model 3 – Switching function of Arm • Each MMC arm are modeled as controlled current and voltage sources for ON/OFF states and
half diode bridge for Blocked state. • These models can be used to study harmonics generated and control system which account
for energy regulation of MMC-arm. • It suppose that Capacitor voltages balancing control operate correctly
Assuming that:
3. MMC models
10
+
-D
+
-
+
-
+
-
ns Xnsarmi
ONNR
ONNR
2D
1D
a) ON/OFF states
b) BLOCKED state
C
N
+
-
armi
+
-
armv
X
Ctoti
Ctotv
Ctotv
+
.
.
arm n C ON armtot
C n armtot
v s v NR i
i s i
1
N
i
in
S
sN
1 2...
CtotC C Ci
vv v v
N
where:
-> For ON state 1iS
0iS -> For OFF state
11
MMC Model 3
DLL block
Fortran 95 code
3. MMC models
Switching function model of MMC arm
+
NP
AC
S_up_A
S_up_B
S_up_C
S_low_A
S_low_B
S_low_C
i_up_A
i_up_B
i_up_C
i_low_A
i_low_B
i_low_C
Vctot_up_A
Vctot_up_B
Vctot_up_C
Vctot_low_A
Vctot_low_B
Vctot_low_C
MMC_SF_arm
N
P
AC
S_up_CS_up_BS_up_A
i(t)
i_low_A i(t)
i_low_B
i(t)
i_low_C
i(t)
i_up_A
i(t)
i_up_B
i(t)
i_up_C
S_low_CS_low_BS_low_A
Vctot_up_A Vctot_up_B Vctot_up_C
Vctot_low_AVctot_low_B Vctot_low_C
V+
-
V+
-
+
SF-arm
Vpos
Vneg
s_arm Vc_tot_arm
arm_up_phA
+
SF-arm
Vpos
Vneg
s_arm Vc_tot_arm
arm_up_phB
mmc
+
SF-arm
Vpos
Vneg
s_arm Vc_tot_arm
arm_up_phC
mmc
+
SF-arm
Vpos
Vneg
s_arm Vc_tot_arm
arm_low_phA
+
SF-arm
Vpos
Vneg
s_arm Vc_tot_arm
arm_low_phB
+
SF-arm
Vpos
Vneg
s_arm Vc_tot_arm
arm_low_phC
+L
10
#L
arm
#
+L
16
#L
arm
#
+L
17
#L
arm
#
+L
18
#L
arm
#
+L
19
#L
arm
#
+L
20
#L
arm
#
scopeVarm_up_A
scopeVarm_low_A
a
c
Model 4 – AVM (Average Value Model) • The AC and DC side characteristics are modeled as controlled current and voltage sources. • These models can be used to study harmonics generated by such converters. • AVM model suppose that internal variables of MMC (Capacitor voltages and current of each
arm) are controlled correctly
AC side: DC side:
𝑒𝑐𝑜𝑛𝑣𝑗 =𝐿𝑎𝑟𝑚2
𝑑𝑖𝑗
𝑑𝑡− 𝑣𝑗
𝑒𝑐𝑜𝑛𝑣𝑗 = 𝑣𝑟𝑒𝑓𝑗𝑉𝑑𝑐2
𝐼𝑑𝑐 =1
2 𝑣𝑟𝑒𝑓𝑗𝑗=𝑎,𝑏,𝑐
𝑖𝑗
𝑃𝐴𝐶 = 𝑃𝐷𝐶 𝑖 = 𝑎, 𝑏, 𝑐
3. MMC models
12
/ 2armL
convce
convbe
convae
av
bv
cv
refabcv
+
+
+
+
+
+
𝑒𝑐𝑜𝑛𝑣𝑗 = 𝑣𝑟𝑒𝑓𝑗 . 𝑉𝑑𝑐/2
dcI
refabcv
lossR armdcL
dcC dcV
+
+
+
+
1
2 𝑣𝑟𝑒𝑓𝑗 𝑖𝑗
13
MMC Model 4
AVMMMC
+
NP
AC
varefvbrefvcref
Trip
AVM1
3. MMC models
AC
Pa
ge
Ia
Pa
ge
Ib
Pa
ge
Ic
PageVcrefPageVbrefPageVaref
AC_side
VacVdcVref
AC_side_phA
+
0/1e15
+
0/1e15
+
0/1e15
PageVc_tot PageVc_totPageVc_tot
AC_side
VacVdcVref
AC_side_phB
AC_side
VacVdcVref
AC_side_phC
N
P+
L1
#Larm_eq_DCside_AVM#
+
cI1
0/1e15
+C1
!v#C_eq_DCside_AVM# V
+
-Page Vc_tot
Trip
+
#R_eq_DCside_AVM#
R1
DC_side
Iac_phAIac_phBIac_phC
I_dcVref_phBVref_phA
Vref_phC
DCside1
PageIc
PageIa
PageIb
PageVcref
PageVbref
PageVaref
++
+L2
#L
arm
_e
q_
AC
sid
e_
AV
M#
+L3
#L
arm
_e
q_
AC
sid
e_
AV
M#
+L4
#L
arm
_e
q_
AC
sid
e_
AV
M#
i(t) Iac
a
b
c
However the control system is much more complex Upper control (VSC control) Since MMC topology is a VSC type, the generic Outer/Inner Control can be used Lower control (MMC control) Controller related to the MMC topology, in order to control internal variables
14
+
+
X +
S R
2
P sin( ) P ( )
cos( ) ( )
S RR R
S R RR R R
V Vfct
X
V V VQ Q fct V
X
Basic idea: By linearizing the power equation, active and reactive power can be decoupled, thus: • Regulating the phase angle -> active power is controlled • Regulating the voltage amplitude -> reactive power is controlled
14
4. Control system
15
Control system structure
Low
er level con
trol
Up
per
leve
l co
ntr
ol
DC
side
gate signal
Yg/∆
CBA
Outer Control
P/Q/Vdc
AC side
MMC
measurements
ˆabce
Inner Control
NLC
Modulation
CCSC
ˆ ˆet abc abc
SM SM
up lowv v
et abc abcup lows s
4. Control system
+
SRC1
+
SRC2P1 P2
N2N1
Cable_70km1
MMC
monopolemodel1400 SM
VSC_1
MMC
monopolemodel1100 SM
VSC_2
16
HVDC link modeled in EMTP-RV
Equivalent source
VSC-MMC station
Underground cable
DC fault pole-to-pole
AC fault (3LT)
5. HVDC-MMC model in EMTP-RV
Pac control VDC control
NB: This test case is included in the examples folder of EMTP-RV 2.5
17
5. HVDC-MMC model in EMTP-RV
Section related with Type of model and circuit configuration
Section related with electrical parameters of the MMC station
Section related with the start-up sequence if checked
18
5. HVDC-MMC model in EMTP-RV
Section related with the control type
Section related with protection system
Exported Mask,do not modify
Scope :
AC1 2
-30
Exported Mask
1/1
Converter_Tfos
p
n
+
Sta
r_p
oin
t_re
acto
r
4k,6
50
0
Page i_up_A
Page i_low_A
Page i_up_B
Page i_low_B
Page i_up_C
Page i_low_C
Page Vc_up_C
Page Vc_up_B
Page Vc_up_A
Page Vc_low_C
Page Vc_low_B
Page Vc_low_A
PageS_up_A
PageS_low_A
PageS_up_BPageS_low_B
PageS_up_C
PageS_low_C
Page Vdc
Page
V_
Se
co
nd
ary
_T
ran
sfo
Page
I_S
eco
nd
ary
_T
ran
sfo
Page
V_
Prim
ary
_T
ran
sfo
Page
I_P
rim
ary
_T
ran
sfo
+
1000
Pa
ge
AC
_B
RK
Pa
ge
Co
nve
rte
r_B
RK
Page Idc
v i
Secondary2
v i
Primary2
V+
-
i(t)
+
AC_BRK
+
AC_convertor_BRK
MMC 21Levels
Capa.
Voltages
Gate
signals
Input Ouput
Current
Arms
i_up_A
P
i_up_B
i_up_C
i_low_A
i_low_B
N
i_low_C
AC
S_up_B
S_up_A Vc_up_A
Vc_up_B
Vc_up_CVc_low_C
Vc_low_B
Vc_low_AS_low_A
S_low_B
S_low_CS_up_C
MMC_21L1
Va_ref
Vb_ref
Vc_ref
Page Vabc_ref
Page S_up_A
Page S_low_A
Page S_up_B
Page S_low_B
Page S_up_CPage S_low_C
PageVc_up_C
PageVc_up_B
PageVc_up_A
PageVc_low_C
PageVc_low_B
PageVc_low_A
Pagei_up_A
Pagei_low_A
Pagei_up_B
Pagei_low_B
Pagei_up_C
Pagei_low_C
Lower Level Control
Gate
signals
Capa.
Voltages
Current
Arms
Va_refVb_refVc_ref
Vc_low_AVc_up_A
Vc_up_B
S_up_A
Vc_low_B
Vc_up_C S_up_CVc_low_C S_low_C
S_up_BS_low_B
S_low_A
theta
i_up_C
i_up_B
i_low_C
i_low_B
i_up_Ai_low_A
MMC_control
Lower_Level_Ctrl1
Pa
ge
blo
ck_
MM
CSMprotection
B1 B2B3 B4
B5 B6B7 B8
B9 B10B11 B12
order
SM_protection
scope
I_circular_phA
f(u)1
2
(u[1]+u[2])/2
PageVdc
scope
Vref_phA
PageV_Secondary_Transfo
PageI_Secondary_Transfo
PageV_Primary_Transfo
PageI_Primary_Transfoia
vava
ia
scope
V�_Primary_ph
scope
I�_Primary_phA
scope
V�_Secondary_phA
scope
I�_Secondary_phA
PageVdc scope
VdcPageV_Primary_Transfo
PageI_Primary_Transfo
PageV_Secondary_Transfo
PageI_Secondary_Transfo
PageVabc_ref
Va_ref
Vb_ref
Vc_ref
Page P_meas
Page Q_measPageP_meas
PageQ_meas
scope
P_meas
scope
Q_meas
PageIdc
Page Converter_BRK
Page AC_BRK
Page block_MMC
#base_dc_Irated#
#base_ac_Vrated#
#base_ac_Irated#
#base_dc_Vrated#
Start-up sequenceand Protection system
converter_BRK
AC_BRKIdc
block_MMC
Start_up_Protect1
PageConverter_BRK
PageAC_BRK
Pageblock_MMC
scope
Converter_BRK
scope
block_MMC
scope
I_circular_phA
Pagei_up_A
Pagei_low_A Iarm in pu oi
Idc in pu oiPageIdc scope
Idc
Vdc in pui o
PageVc_up_A
PageVc_low_A
Vc1
Vc20
scope
Vc1_up_phA
scope
Vc20_up_phA
Vc1
Vc20
scope
Vc1_low_phA
scope
Vc20_low_phA
Iarm in pu oi
1
#base_Vcapa_SM#
1
#base_Vcapa_SM#
1
#base_Vcapa_SM#
1
#base_Vcapa_SM#
scope
AC_BRK
Upper Level Control
V_Secondary_Transfo
I_Secondary_Transfo
Vabc_ref
V_Primary_Transfo
I_Primary_Transfo
Vdc_measVdc
theta
P_measQ_meas
Upper_Level_Ctrl
AC_Converter
19
MMC model 1 to 4 Power Transformer
Acquisition system Control and Protection System
DC side AC side
Subsystem structure of the VSC-MMC station
5. HVDC-MMC model in EMTP-RV
20
5. HVDC-MMC model in EMTP-RV
MMC model comparisons under AC fault Simulation configuration: MMC-401Level (N = 400SMs/arm) Time-Step = 10us Three-phase to ground fault of 200ms after 1sec of simulation
0.95 1 1.05 1.1 1.15 1.2 1.25 1.3 1.35 1.4-2
-1
0
1
2
curr
ent
(pu)
time (s)
0.95 1 1.05 1.1 1.15 1.2 1.25 1.3 1.35 1.4
-1
-0.5
0
0.5
1
voltage (
pu)
time (s)
Model 1, 2 and 3
Model 1, 2, 3 and 4
Model 4
ai
0.95 1 1.05 1.1 1.15 1.2 1.25 1.3 1.35 1.4-2
-1
0
1
2
curr
ent
(pu)
time (s)
0.95 1 1.05 1.1 1.15 1.2 1.25 1.3 1.35 1.4
-1
-0.5
0
0.5
1
voltage (
pu)
time (s)
Model 1, 2 and 3
Model 1, 2, 3 and 4
Model 4
av
0.95 1 1.05 1.1 1.15 1.2 1.25 1.3 1.35 1.4-1.5
-1
-0.5
0
0.5
curr
ent
(pu)
time (s)
0.95 1 1.05 1.1 1.15 1.2 1.25 1.3 1.35 1.40.95
1
1.05
1.1
1.15
voltage (
pu)
time (s)
Model 4
Model 1, 2 and 3
Model 4
Model 3Model 1 and 2
dcI
0.95 1 1.05 1.1 1.15 1.2 1.25 1.3 1.35 1.4-1.5
-1
-0.5
0
0.5
curr
ent
(pu)
time (s)
0.95 1 1.05 1.1 1.15 1.2 1.25 1.3 1.35 1.40.95
1
1.05
1.1
1.15voltage (
pu)
time (s)
Model 4
Model 1, 2 and 3
Model 4
Model 1 and 2 Model 3
dcV
MMC-2 phase A current: MMC-2 phase A voltage:
MMC-2 dc current: MMC-2 dc voltage:
21
5. HVDC-MMC model in EMTP-RV
MMC model comparison under DC fault Simulation configuration: MMC-401Level (N = 400SMs/arm) Time-Step = 10us Permanent Pole-to-pole DC fault at 1.9sec of simulation
1.85 1.9 1.95 2-5
0
5
curr
ent
(pu
)
time (s)
1.85 1.9 1.95 20
5
10
curr
ent
(pu
)
time (s)
Model 4
Model 1, 2 and 3
Model 4
Model 1, 2 and 3ai
1.85 1.9 1.95 2-5
0
5
curr
ent
(pu)
time (s)
1.85 1.9 1.95 20
5
10
curr
ent
(pu)
time (s)
Model 4
Model 1, 2 and 3
Model 1, 2 and 3
Model 4
Zoomed
dcI
1.898 1.9 1.902 1.904 1.9060
2
4
6
8cu
rren
t (p
u)
time (s)
1.898 1.9 1.902 1.904 1.9060
2
4
6
8
curr
ent
(pu)
time (s)
Model 1, 2 and 3
Model 4
dcI
MMC-1 ac current: MMC-1 dc current:
Zoomed MMC-1 dc current:
22
Computation performances • 401-levels MMC based HVDC link was tested for 1sec simulation. • The simulation time is compared for all models • The best computing performance is given by Model 4
5. HVDC-MMC model in EMTP-RV
Model Time step
(μs)
Computation time (s) in function of SMs/arm
20 50 100 400
# 1 10 258 822 2,106 13,459
# 2 10 37 65 114 441
# 3 10 18 18 18 18
# 4 10 15 15 15 15
# 4 100 2 2 2 2
6. References
23
• Saad H., Dennetière S., Mahseredjian J., Delaru P., Guillaud X., Peralta J., Nguefeu S., “Modular multilevel converter models for electromagnetic transients,” submitted to IEEE Trans. on Power Delivery, TPWRD-00396-2013
• Saad H., Dufour C, Dennetière S., Mahseredjian J., Nguefeu S., “Real Time simulation of MMCs using the
State-Space Nodal Approach,” accepted in IPST 2013, International Power System Transient Conference
• Saad, H.; Peralta, J.; Dennetiere, S.; Mahseredjian, J.; Jatskevich, J. and al, "Dynamic Averaged and Simplified Models for MMC-Based HVDC Transmission Systems," Power Delivery, IEEE Transactions on , vol.PP, no.99, pp.1,10
• Peralta J., Saad H., Dennetiere S., Mahseredjian J., Nguefeu S. "Detailed and Averaged Models for a 401-
Level MMC–HVDC System," Power Delivery, IEEE Transactions on, vol. 27, no. 3, pp. 1501-1508, July 2012
• Peralta J., Saad H., Dennetiere, S., Mahseredjian, J., "Dynamic performance of average-value models for multi-terminal VSC-HVDC systems," Power and Energy Society General Meeting, 2012 IEEE, pp. 1-8, 22-26 July 2012