Analysis of CD-PAR Benefits and

Technical Performance

Alberto Del Rosso, PhD - EPRI

ARPA-E GENI Program Review

New Orleans, LA

January 13-14, 2015

Compact Dynamic Phase Angle Regulators (CD-PAR) for

Transmission Power Routing

1

CD-PAR Objective

2

CD-PAR

P/Q Control

• Control phase angle to control real power

• Control voltage magnitude to control reactive power

• Control real and reactive power dynamically

• Can be installed around existing sectionalizers

-1 -0.5 0 0.5 1-1

-0.5

0

0.5

1

Real Power, PU

Re

active

Po

we

r, P

U

VQS

Constant Duty

Control of P/Q Between Two Buses

VQS enables in-phase injection

Goals of the study

‣ Contribute to articulate value proposition of CD-PAR

technology:

– Evaluate the impact of CD-PARs on system metrics including

thermal overload relief, stability, and reliability improvement

– Evaluate the use of CD-PARs to increase transmission capacity:

• Divert power flow to reduce congestion

• Improve voltage and angle stability

• Control strategies: preventive measure - remedial measure

– Analysis of the use of CD-PARs to improve distribution system

efficiency and utilization

3

Approach

‣ Case studies on synthetic and actual power system models

4

CD-PAR 1

5 control

96 MW

80% short

term rating 117 MW

98% short

term rating

35 MW

Additional load

Line out

Critical contingency

46 MW

38% short

term rating

0

50

100

150

200

250

300

350

400

1 501 1001 1501 2001 2501 3001 3501 4001 4501 5001 5501 6001 6501 7001 7501 8001 8501

Wind

without CD-PAR

with CD-PAR

Transmission Sub-transmission Distribution

•Reduced wind generation

curtailment

•Two systems: Alberta

Electric System, Utility in NY

• Increased network

loadability

• Differ investment

• Improved utilization by

balancing load among

feeders and

substations

Modeling for system studies

5

i k

j

P,Q

CD-PAR

Control LogicP[MW] Q[Mvar]

α tap

V

I

P

POD Signal

(a)

α tap

CD-PAR

Phase Angle

Command

CD-PAR

Tap

Command

0 0

K2max

–+ S

K1

K2

Tds

Kds

s

KiKp

P

PPP

1 Tds

Kds

s

KiKp

Q

QQQ

1S

+

Qref

Qkj

+

–

S+

Pref

Pij

f

POD

sT

K

1

Vmin

Vmax

4

3

1

1

sT

sT

2

1

1

1

sT

sT

w

w

sT

sT

1POD

CD-PAR Control Logic

K0max

PVmax

PVmin

QVmax

QVmin

s0 s1 s2 s3

s4 s5 s6 s7

v4

v2 v3

v6

v0v1

Vs

v5

K0

(b)

i k

j

P,Q

CD-PAR

Control LogicP[MW] Q[Mvar]

α tap

V

I

P

POD Signal

(a)

α tap

CD-PAR

Phase Angle

Command

CD-PAR

Tap

Command

0 0

K2max

–+ S

K1

K2

Tds

Kds

s

KiKp

P

PPP

1 Tds

Kds

s

KiKp

Q

QQQ

1S

+

Qref

Qkj

+

–

S+

Pref

Pij

f

POD

sT

K

1

Vmin

Vmax

4

3

1

1

sT

sT

2

1

1

1

sT

sT

w

w

sT

sT

1POD

CD-PAR Control Logic

K0max

PVmax

PVmin

QVmax

QVmin

s0 s1 s2 s3

s4 s5 s6 s7

v4

v2 v3

v6

v0v1

Vs

v5

K0

(b)

Phase Shifter

(1 Phase Shown)

`

Bridging Auto

Filter

Voltage/ Reactive Power

Regulator

Active Power Regulator

-OR-

For OpenDSS: 3-phase model

For PSS/E: Static and dynamic models

CD-PAR Control Capability

6

• Nominal voltage: 138.0 k V

• CDPAR sec. voltage: 500 V

• 90 km transmission line

• Maximum Phase Angle of CD-PAR

α : ±2 degrees

0

20

40

60

80

100

120

140

10 40 80 140

Po

we

r (M

W)

Length (Km)

0

20

40

60

80

100

120

140

160

±2 ±5 ±10 ±15

Po

wer

(MW

)

Phase Angle Range (Degrees)

Active power vs. line length Active power vs. max. CD-PAR phase

angle shift

CD-PAR

Use of CD-PAR to Improve Wind Integration

7

Wind Injection:

Calgary

• Alberta Electric System Operator

Coverage Map

• Hypothetic case

Scenario: Interconnection request for 350 MW

Wind Plant

8

262DOME EM4

1.1258.3

677CYPRES2

1.1258.0

SW

7.4

6% S

267DOME EM7

1.0142.7

674CYPRES1

1.0143.0

911EMPLIQTP

1.0142.6

53SANDYPT7

1.0142.7

111SANDHIL7

1.0142.7

266EMPRESA7

1.0142.9

34.1

1.0

639

1 65.6

37.6

338.0

100.0L

52.1

SW

0.0

0.0

1 2.7

7

0.0

0.0

1

1473MCNEILL

1.0143.0

320CHAPPIC7

1.0138.5

32.7

17.71

1.0

272

32.7

18.5 32.7

17.61

1.0

272

32.6

18.534

0.1

0.0SW

0.0

65.5

1

100% S

40% S

21% S

25% S

38% S

114% I

39% S

N/A

N/A

19% S

19% S

N/A

59% S

900001PAR_1

900002LTC

0.9214.0

0.0

0.0

0.0

0

1.0237.8

N/A

CD-PAR

• Injection limit due to N-1

conditions

•Limit without CD-PAR:

215 MW

•Limit with CD-PAR: 330

MW

• Wind spillage reduction

174 GWh

•CD-PAR controlled for N-1

as well as N conditions:

Short term rating >

permanent rating

•

1

25.0

100.0

50.0

1

75.0

48.3R

1

1.0

00

0

1.0

00

0

-1.6R1

.00

00

1.0

00

0

0.9

99

8

1.0

00

00

.22

1.00013.8

1.000230.0

1GENERATOR

1.000230.0

1.000230.0

901PAR_1

911LTC

2LOAD

3GSU_BUS

1.0004.2

Generator angle excursion

No CD-PAR

230/13.6 kV CD-PAR

Use of CD-PAR for Power Oscillation Damping

9

Channel Plot

2 - ANGL 3[GSU_BUS 13.800]1 : test_POD_doublegfedcb2 - ANGL 3[GSU_BUS 13.800]1 : test-SMIBgfedcb

Time (seconds)

11109876543210

150

125

100

75

50

25

0

-25

-50

-75

-100

CD-PAR

1

6

1

7

1

1

8

9

1

10

4

113

1

1

5

CD-PAR

kV: >0.000 <=138.000 <=345.000

2

1

G3

G4

1

G2

G1

25 KM

10 KM 110 KM 110 KM10 KM 25 KM

<=15.000

Area 2Area 1

Tie Line

<=230.000

Bus - VOLTAGE (kV/PU)Branch - MW/MvarEquipment - MW/Mvar

GENERATOR G1 (ANGLE)

Time (seconds)

2522.52017.51512.5107.552.50

65

60

55

50

45

40

35

30

25

20

15

10

Potential Applications in Distribution Systems

10

CD-PAR

12/16/20 MVA 12/16/20 MVA

25 MVA 15 MVA

5 MVA

20 MVA 20 MVA

Transmission (HV)

System

TRANSMISSION GRID

CD-PAR

P, Q

Sub B

Feeder BFeeder A

Sub A

B) Balancing Substation

Transformer Loading

A) Feeder Support

Between Remote

Substations

Feeder Support Between Remote Substations

11

OpenDSS Model of Actual Feeders

‣ Analyze the capability of the CD-PAR to

attain desired power flows to the load at the

feeders’ ends

Objective of the Study

• Each feeder serves half the load (equal

sharing)

Control Target

-1500

-1000

-500

0

500

1000

1500

-6 -4 -2 0 2 4 6

Ta

rge

t M

ism

atc

h (

kW

)

Degree Phase Angle Difference (Moreland - Morningside)Phase angle difference (Sub A – Sub B)

CD-PAR capabilities are affected by: • Feeder characteristics where CD-PAR will be

installed

• Feeder loading

• Variation of phase angle difference on

transmission system

Sub-transmission system case

12

CD-PAR 1

5 control

96 MW

80% short

term rating 117 MW

98% short

term rating

35 MW

Additional load

Line out

Critical contingency

46 MW

38% short

term rating

CD-PAR 2

5 control

Combined distribution and 60 kV

subtransmission network that feed a medium

size city in CA

Inflow

• Maximum additional load with CD-PAR 1: 35 MW

• Maximum additional load with both CD-PAR 2: 55

MW

Conclusions

‣ CD-PAR can improve efficiency and utilization of transmission and

distribution systems

‣ CD-PAR can be effectively used to damp power system

oscillations

‣ The use of CD-PAR for multiple uses may improve the value

proposition – technically feasible

‣ Control interactions need to be considered:

– Between the different control loops of a CD-PAR device

– With other devices on the system

‣ Practical implementation: Event based Special Protection Scheme

13

What else is needed to demonstrate the value

proposition?

‣ Detailed evaluation of other potential benefits:

– i.e.: enabler of system flexibility

‣ Economic assessment of benefits and cost:

– benefits, and beneficiaries

‣ Detailed technical and economic comparison with alternative

solutions

‣Mathematical models to determine optimal location and

capacity of CD-PARs

‣ Demonstrate the role of power flow controllers in the grid of

the future – The integrated grid

14