Testing and Comparing Microgrid Controllers Performance Aspects Using Hardware-in-the-Loop Simulations

Microgrid Testbeds & Controller Procurement

Agenda ESIF-NREL intro

Microgrid Controller Procurement 2017

Microgrid testbed

Model validation

Test sequences

Controllers evaluation criteria

Example results

NREL – ESIF

Energy Systems Integration Facility (ESIF)

Clean, reliable, and affordable energy at a pace and scale that matters

https://www.nrel.gov/esif/

μGC Procurement NREL is seeking a microgrid control technology for

installation in a permanent microgrid research testbed at the Energy Systems Integration Facility located in Golden, Colorado.

The top-performing control technology will be installed at ESIF in 2018

Testing microgrid controls

* Pictures from “Development of a Real-Time Hardwarein-the-Loop Power Systems Simulation Platform to Evaluate Commercial Microgrid Controllers”, R.O. Salcedo J.K. Nowocin C.L. Smith R.P. Rekha E.G. Corbett E.R. Limpaecher J.M. LaPenta

MIT Microgrid Symposium 2017github.com/PowerSystemsHIL

NREL Stage 1 - CHIL NREL Stage 2 - PHIL

Simulated Microgrid Single phase nodes: 291x

3x Synchronous Generators with controls

2x ESS (VSI, Battery with controls)

2x PV (VSI with controls)

49x CB with Protective Relays

1x DMS interface

OP6500 – 12 cores utilized to run 100μs

Single line diagram

Single line diagram – PHILReal power hardware:•270kVA Amatek grid simulator•AE100 100kVA PV inv•Magna power DC - PV simulator•Caterpillar BDP250 –250kVA ESS inverter•AV900 bi-directional DC supply – battery emulator•250kW LoadTec loadbank•ABB CB•Onan Cummins 80kW diesel generator

HMI & DAQ

• Real time visualization of microgrid status using off-the-shelf RTAC

• Matlab used as test sequence generator and DAQ system

• MatlabOpal-RTcommunication using UDP

Controller interface Based on Ethernet only

50x IEC61850 GOOSE messages (Opal-RT)

56x Modbus TCP interfaces (Opal-RT)

Direct Modbus&IEC61850 communication to devices in PHIL

Load flow validation

Islanded Load flowReal time Error [%]

C3– V (pu) 1.00 0.99 0.88

C4– V (pu) 0.99 0.98 0.95

ESS– V (pu) 1.00 1.00 0.31

ESS– P (MW) 0.81 0.84 3.43

ESS– Q (MVAR) 0.88 0.85 3.08

PV– V (pu) 1.00 1.00 0.43

PV– P (MW) 1.00 1.00 0.22

PV– Q (MVAR) 0.00 0.00 0.00

… … … …

SimPowerSystemsLoad flow

Opal-RTReal-Time execution

Steady state comparison

Inverse load flow validationOpal-RT

Real-Time executionSimPowerSystems

Load flowSteady state comparison

PointLoad flow

Real time Error [%]

C1 – V (pu) 0.994 0.993 0.13C2 – V (pu) 0.985 0.984 0.13I1 – V (pu) 0.993 0.992 0.08I2-V (pu) 0.990 0.989 0.06P1-V (pu) 0.975 0.974 0.15GEN1 – V (pu) 1.001 1.000 0.10GEN1 – P (MW) 3.600 3.600 0.00GEN1 – Q (MVAR) 1.720 1.720 0.00Motor1-V (pu) 0.986 0.960 2.64C3 – V (pu) 0.996 0.993 0.30C4 – V (pu) 0.993 0.990 0.30

Transient behavior validation

Transient behavior validation

Load shedding 1.2MW

Frequency drop to 56.3Hz (compared to 55.0Hz)

Test sequence - stimuli

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 1000

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

t [min]

[PU

]

Irradiance PV1

Irradiance PV2

Grid energy price

Test sequence – grid stimuli

6 7 8 9 10 1159.55

59.70

59.85

60.00

60.15

60.30

60.45Grid frequency

[Hz]

6 7 8 9 10 11-5000

-2500

0

2500

5000

7500

10000DMS active power reference tolerances

[kW

]

time [min]

Test sequence – stimuli

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100mgc.en

dms.disconnect

grid.cut

motor1

motor2

fault.pv2

fault.pv1

fault.ess2

fault.ess1

fault.gen3

fault.gen2

fault.gen1

fault.loc6

fault.loc5

fault.loc4

fault.loc3

fault.loc2

fault.loc1

time [min]

Key Performance Parameters (KPP)KPP1 - Resiliency and Reliability

Measured by calculating the energy delivered to predetermined categories of load. A penalty will be added for any outage on critical loads.

KPP2 - Operation and Maintenance

The cost of fuels to run DER’s and values device degradation from use (e.g. causing faster failure, circuit breakers use).

KPP3 - Interconnection Contract

The price of energy during the test sequence will vary to allow the controller to benefit from various choices (e.g. dispatching energy from battery).

KPP4 - Distribution Service Operator (DSO) Commands

The microgrid controller can allow additional revenue by providing services to DSO on request. Failing to provide required services will result in a penalty.

KPP5 - Power Quality

Voltage and frequency violating IEEE 1547a-2014 clearing times (Tables 1 and 2 of the standard) will be counted. of the standard will be counted.

KPP6 - Microgrid Survivability

Keeping battery State of Charge (SoC) below the predetermined level during grid connected conditions will result in a penalty.

KPP7- Fuel- Free Asset Utilization

The amount of energy generated from PV to supply 1MWh of loads in the microgrid and PV energy generation will be measured.

KPP8 – Economic operation

Dollar sum of KPP1 to KPP7 allowing for overall comparison of various controllers under test

KPP1 – Resiliency Energy delivered to Critical loads (EC)

EC [kWh] P11 = 1.00[$/kWh]

Energy delivered to Priority loads (EP)

EP [kWh] P12 = 0.90[$/kWh]]

Energy delivered to Interruptible loads (EI)

EI [kWh] P13 = 0.85[$/kWh]

Energy Critical loads Outage (ECO)

ECO [kWh] P15 = 4.50 [$/kWh]

Energy Priority loads Outage (ECO)

EPO [kWh] P16 = 2.25 [$/kWh]

Energy left in ESS at the end of the sequence compared to initial state of charge

EESS [kWh] P17 = 1.00 [$/kWh]

10 20 30 40 50 60 70 80 900

5000

10000

15000kW served by load class

M

I

P

C

10 20 30 40 50 60 70 80 90-2

-1

0x 10

4kW outage by load class

0 10 20 30 40 50 60 70 80 90

-4000

-2000

0

2000

4000

time [min]

KPP1 summary values [$]

M I P C

KPP2 – Operational costsUsed Fuel - Diesel (FD) FD [gal] P21 = 74.55 [$/gal]

Used Fuel- Natural Gas (FNG)

FNG [m3] P22 = 4.18 [$/m3]

Number of Diesel starts (ND)

ND P23 = 10 00[$]

Number Combined Heat & Power re-starts (NCHP)

NCHP P24 = 10.00 [$]

Number of Battery cycles (NB)

NB P25 = 10.00 [$]

Number of Circuit Breaker cycles (NCB)

NCB P26 = 1.00 [$]

Energy delivered as Heat (EH)

EH

[MBtu]P28 = 147.00[$/MBtu]

5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95-10000

-5000

0Fuel costs per hour [$/h]

Diesel1

Diesel3

CHP2

5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 950

500

1000CB switches count [unit]

5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95-10000

-5000

0

5000KPP2 summary values [$]

time [min]

Diesel1 NG2 Diesel3 Heat2 CB switch

KPP3 – Interconnection contract

Exported Energy (EE) EE [kWh] PE [$/kWh] (p31)

Exported Energy Over limit (E E0)

EE0 [kWh] PEO [$/kWh] (p32=p31*kEO)

Energy imported (bought from grid. EB)

EB [kWh] PB [$/kWh] (p31)

Energy imported over limit (bought from grid, EBO)

EBO [kWh] PBO [$/kWh](p33=p31*kBO)

Reactive power over limit penalty

ERP [kVArh] P33 = 0.50 [$/kVArh]

12 13 14 15 16 17 18 19

-5000

0

5000

10000

15000

20000

Active power at POI [kW]

12 13 14 15 16 17 18 19-6000

-4000

-2000

0

2000

4000

6000Reactive power at POI [kVAr]

12 13 14 15 16 17 18 19

-2000

-1800

-1600

-1400

-1200

KPP3 summary values [$]

time [min]

EBO

EB

EE

EEO

ERP

Active Power Import Limit = 12 MWActive Power Export Limit = 6 MWReactive Power Limit = 5 MVAr

KPP4 – Grid servicesMeeting dispatch command premium (DP). Power imported from Grid to μG

TDP min P41 = 23.60 [$/min]

Meeting demand command premium (DM). Power exported from μG to Grid

TDM min P41 = 23.60 [$/min]

Following Volt/Var support premium (VV)

TVV min P43 = 290.00 [$/min]

Following Demand response curve (Freq/kW, FkW)

TFkW min P44 = 149.50 [$/min]

Meeting power factor request (PF) TPF min P46 = 11.21 [$/min]

Violating planned disconnect request (DR)

TDR min P45 = 19.50 [$/min]

Unplanned disconnect – failure to disconnect (UD)

TUD min P47 = 26.40 [$/min]

2 4 6 8 10 12 14 160

2000

4000

6000

8000

Active power at POI [kW]

2 4 6 8 10 12 14 16-6000

-3000

0

3000

6000

9000

Reactive power at POI [kVAr]

2 4 6 8 10 12 14 160

100

200

300KPP4 summary values [$]

time [min]

T

TD/M

TFkW

TPF

TVV

TDR

TUD

KPP5 – Power quality

• Voltage monitored on every bus

• According to IEEE 1547a-2014

• Fault integrators implemented in real time

* Table 1 from IEEE1547a-2014 standard

KPP5 – Power quality

• Frequency monitored on every bus

• According to IEEE 1547a-2014

• Fault integrators implemented in real time

* Table 2 from IEEE1547a-2014 standard

KPP6 – Microgrid survivability

• Penalty is issued when SoC is below 40% during grid connected operation

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 1000

20

40

60

80ESS state of charge [kW]

ESS1

ESS2

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100-350

-300

-250

-200

-150

-100

-50

0KPP6 summary values [$]

time [min]

ESS1

ESS2

KPP7 – Free assets utilization

38%

17%

15%

7%

14%

9%

Total energy consumed = 21778 kWh

Grid

Gen1

NGCHP2

Gen3

PV1

PV2

2%

17%

34%

47%

Consumption by loads = 19624 kWh

M

I

P

C

• >25% energy can come from solar in this test pattern

• >43% power can come from solar at peak irradiation

• Solar doesn’t have a cost associated thus it is very favorable to use it

KPP8 – Summary result

0 20 40 60 80 100-12000

-10000

-8000

-6000

-4000

-2000

0

2000

4000KPP8 - sum of KPP1..KPP7 [$]

Test case 1 Test case 2

0 20 40 60 80 100-1.5

-1

-0.5

0

0.5

1

1.5

2x 10

4KPP8 - sum of KPP1..KPP7 [$]

KPP1

KPP2

KPP3

KPP4

KPP5

KPP6

KPP8

Next steps Currently in are at Stage 1 (CHIL) and validating Team #4

We will publish details about competition winner’s strategies and analyze various teams’ approaches

Models will be published after procurement: github.com/mgcp2017/

AcknowledgementsThis work was supported by the U.S. Department of Energy. NREL would like to thank MIT Lincoln Laboratories for their collaboration on this project.

THANK YOU