OOO OOOO

• First Demo. Proj. of KEPCO

(Peak Shaving, Freq. Regulation

Renew. Power Stabilization)

• Prove commercial FR ESS cntlr.

Jocheon Facility (Jeju Island) 4 MW / 2 hr.

Demonstration

2011 – 2014

Flexible ESS Project 2015 – 2018

Development of Flexible ESS Tech

• 28 MW ESS for Phase I (60 MW) of 2.5GW Offshore Wind Farm

• ESS value up with changing op. strategy depending on the needs of the power grid

F/R ESS Commercialization

2014 – 2018

F/R-ESS Project

•KEPCO BM Proj.(52MW ESS) (Seo-Anseong 28 MW, Shin-Yongin 24 MW)

•And total 500 MW by 2018

28 MW /15 min. (Seo-Anseong)

Energy Storage System • Rated Power : 4MW (1MW PCS X 4) • Rated Energy : 8MWh (1MWh battery in 40ft Container X 8) • Control : Single PMS (Power Management System) • 23kV Grid interconnection

1MW ES-PCS Panel

Main control panel

Inverter panel Battery power

Incoming panel

Test item (PCS)

• Efficiency (Average 95.5%)

• Harmonics (Under 5% THD)

• Power Factor

• Response time (about 16ms)

• Protection

Test item (Battery System)

• Cell balance, Efficiency, etc.

-1

0

1

2

3

4

59.8

59.9

60.0

60.1

60.2

1 2 3 4 5 6 7 8 9 10

주파수(With ESS) 주파수(Without ESS) ESS

※ 피크부하 : 58.2 ▶ 55.1 MW(5.3% 저감)

45

50

55

60

1 3 5 7 9 11 13 15 17 19 21 23

조천S/S 부하 충전량 방전량 Load (MW)

hour

Freq. (Hz)

Power (MW)

sec

-

2

4

6

8

10

0 1 2 3 4 5

풍력출력 풍력+ESS

Ramp rated : 88%↓, .81.1[%/min]

Wind (MW)

hour

Peak : 3.6%↓(27.426.4 MW)

6.31MWh

7.74MWh

30

25

20

15

wind Wind+ESS Freq. With ESS Freq. Without ESS

S/S Load Charged Discharged

ESS application demonstration

• Peak shaving : peak demand 27.4MW 26.4MW • Frequency regulation • Wind smoothing : Maximum Power fluctuation (8 1.1 %/min)

PCS

Since 2015, ESS (Energy Storage System) for GF (Governor Free) is installed up to 236MW in KEPCO

FR ESS Operational Planned

Total 2015 2016 2017 2018

Rating(MW) 52 184 140* 124 500

No. of Facilities 2 7 4* 4 17

24MW SeoYongIn

28MW SeoAnSeong

16MW ShinChungJu

24MW ShinGyeRyong

24MW ShinGimJe

24MW ShinHwaSun

48MW GimJe

28MW SokCho

36MW NonGong

24MW UiRyeong

48MW Gyeongsan

24MW Ul Ju

36MW Ul San

Seo-Anseong ESS Facility (28 MW) Shin-Yongin ESS Facility (24 MW)

Shin-Hwasun ESS Facility (24 MW) Shin-Gyeryong ESS Facility (24 MW)

Configuration of 24MW FR ESS(example)

154kV

23kV

440V

Main Tr.

ESS Tr.

PCS

Bat

[SAND2013-5131 : DOE EPRI ESS Handbook]

Major objectives is Primary Frequency Control to maximize fast response benefit. • We defined two ESS operation modes 1. Steady state control mode 2. Transient state control mode

FR Algorithm for steady state • Over deadband (±0.03Hz) : droop control with speed regulation • Within deadband : recovery control of battery SOC

0.5 0.63~0.67 0.8

30

-30

△f [mHz]

SOC [p.u]

Charge

Charge Ratio : -10% of Pn

0 Discharge

Discharge Ratio : 5% of Pn

0

0

1.0

Charge Ratio : -5% of Pn

Discharge Ratio : 10% of Pn

0

FR Algorithm for transient state

Operation mode (steady state transient state) • Condition

under 59.97 Hz and ROCOF lesser than - 0.028 Hz/sec during 1000 msec.

• Operation Power : ΔHz × K(sys. freq. char. Constants, 787 MW/0.1Hz)

Exit mode (transient state steady state) • Condition

Positive freq. ramp above 59.9 Hz still after 1 sec • Operation

Speed regulation : 0.16% (Droop control) Until recovering 60 Hz or 6 min after starting exit mode

Seo-Anseong ESS #1(16MW) Transient exit mode : triggered within 200msec. Recovering 60Hz or 6 min after starting exit mode

Response to Hanul NP #1(950MW) trip (‘16.1.19 11:39:48)

deadband

Transient mode Exit mode Steady State

ESS SOC (%) Frequency(hz) ESS Power output(MW)

Frequency (hz)

Issue and future study (Freq. pick-up system) Different ESS response owing to different freq. signal conditioning system

14

ESS response

ShinGimjae UiRyung

ESS P [MW]

Multi-Purpose ESS development Optimal operational strategy for technical and economical solution Supply & demand issue (renewables, peak), power system (FR)

28 MW ESS for renewable energy integration To be integrated with 60 MW off-shore wind farm

Phase I 60 MW

Phase II 440 MW

Phase III 2,000 MW

KEPCO Testing Center

Saemangeum 345kV Substation

5

Substation

Local Control

1C Group (12MW/12MWh)

2C Group (4MW/2MWh)

4C Group (12MW/3MWh)

28 MW ESS configuration • We defined three ESS Group by Power – Energy ratio • ESS group is controlled by LPMS (Local Power Management System) • Whole ESS is controlled by TEMS

6

LPMS application mode LPMS have an adjustable control time step from 20ms to 1hour Operation mode can be changed by user or TEMS Flexible ESS can perform the following functions

7

G/F Arbitrage Peak shaving Wind Shift

Smoothing Ramp limit Capacity firming External control

TEMS control block

LPMS

G/F

Arbitrage

Peak shaving

Wnd REC

Wnd smoothing

Wnd ramp limit

Wnd Cap. firming.

Manual control

Grid System Info.

Emergency Normal Check System State

(hourly cycle)

Assign Optimal LPMS Function

AGC Response

Wind Output Control

Peak Shaving Scheduling

Other Function

Allocate Available ESS Reserves

Op. Mode Control Para.

Freq. Reg. Operation

Wind Output Ramprate Limit

Peak Shaving

Other Functions

Gov. Free AGC

10 min. Ctrl. 30 min. Ctrl. 1 hr. Cntrl

Ld-based SMP-based

Backup Power

Power Rsrv. Support

Allocation of Rsrv.

(per min. cycle)

7

KEPCO demonstrated Energy Storage System (2011~)

Peak shaving, FR, Wind Smoothing by Jocheon 4 MW / 8 MWh in Jeju

Flexible ESS for multi function and fleet control (2014~2018)

KEPCO has got a lot of know-how about operation and installation from about

400MW ESS.

Siting, PCS and BMS performance test, communication design, etc.

PCS and Battery performance also improved.

KEPCO will further develop various technologies to expand the use of ESS.

Multi Modular ESS, Smart Inverter, Etc.

7

Thanks Sungmin Cho Sungmin.cho@kepco.co.kr