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Smart Grid for a

Future Low Carbon Society

November 2nd, 2012

Power Grid Engineering Project

Mitsubishi Electric Corporation

“Norway-Japan cooperation on renewable energy”

1

Solar

Wind

Source: EPIA/ Global Wind Energy Outlook 2011

Renewable Trend in the World

2 Source: METI http://www.enecho.meti.go.jp/saiene/kaitori/index.html

Effect of Feed in Tariff in Japan

New incentive for renewable started July 1st 2012: PV assets register for

FIT benefit increase constantly from that.

0

200

400

600

800

1000

1200

Jul Aug Sep

MW <10kW

>10kW

Jul Aug Sep

<10kW 144 306 444

>10kW 301 724 1035

(>1000kW) (243) (565) (733)

3

Grid Operation Challenges Challenge Reason Technical Solution

1

Frequency deviation Unstable output from

renewable

•Forecasting

•Control for PV and Wind

•Hydro Optimization

(Variable Speed)

• Installation of Battery

2

Excess Power A large amount of

unstable output from

all the PV panels at

low load period

• Installation of Battery

•Control for PV and Wind

•Demand Response

3

Voltage instability Excess power output

from individual PV

panel in the feeder

•Partitioning transformer

•Installation of Voltage

Regulator

•Control for PV

4

● Large amount of photovoltaic may create imbalance in the production and a consequent deterioration of the power quality

● Optimal dispatch of the supply resource coordinating batteries, thermal power plants and pump storage plants

● The dispatch and control algorithm was tested in a scenario with high penetration of photovoltaic and the power quality level (frequency within +/-0.2Hz from nominal value) was ensured

Time

Po

we

r Generation

Time

Pow

er Thermal Pump Storage Batteries

Balance

Management

System

Photovoltaic

Po

we

r

Coordination of Batteries and controllable plants Weather Dependent

Demand Frequency

－ ＋

Nuclear→Fix Production

Pow

er

Distributed Resource Control Signal

Demand Supply Balance Management

5

Micro Grid Energy Management System

Microgrid Configuration (NEDO-Hachinoe） Control based on 4 level operation

● Micro grid technologies support the integration of renewable electricity sources

smoothing the unpredictable fluctuations with a advance energy management system

● In severe conditions, micro grid technologies allowed island operation controlling

batteries and other electricity sources to stabilize voltage and frequency

micro-grid: an integrated energy system consisting of interconnected loads and distributed energy

resources (DER) which as an integrated system can operate in parallel with the [bulk power system]

grid or in an intentional island mode

Private Distribution

Network

Power

Gas

Public Office

Gas

Holder

Batteries

EMS

Methane Gas

Chamber

Schools Commercial

Grid

Operating Plan

Economic load dispatch

Tie-line control

Local Control

Constraints Demand

Correction Operation

Target

Output control Tie-line deviation

Operation Control Local Info

Wood Boiler

Renewable

sources

Microgrid

Heat

Gas Engines

Gas Boiler

6

Keihanna Science City CEMS demonstration project

Energy monitoring of the entire area

Energy consumption data acquisition for each load to understand the regional energy needs

Demand response （DR） program for grid support

Demand response is achieved sending request to single EMS and controlling batteries following the request Connection of the power system operator

CEMS Functions

Incentives for demand

Points are granted to demand that achieve CO2 reduction or demand response targets

CEMS servers at Keihanna Plaza

Request for cooperation

CEMS

Local Community

CO2 emission target Point found info

Point registration for each user

Area Info

Point Management

Revenue to Users

SOC level

EV management center

DR request

BEMS Power System management

Utility

：Communication network ：other

communication

Weather Info

Local Battery

Weather forecast

DR request CO2 target

DR request CO2 target

HEMS

Charge/Discharge Order

Energy use status

Energy use status

Energy use status

7

Keihanna Science City DR mechanism

Calculation of CO2 reduction for each demand

Calculation of power consumption/reduction within the control

band for each demand

Time

Are

a T

ota

l

Con

su

mption

Consumption/Production Target Planed Consumption/Production Band of control

ＣＥＭＳ

Local Battery

Local community

Area CO2 emission target

Utility

Demand/surplus reduction

Control within the upper and

lower bound

Planed Consumption/Production

Band of control

EMS-1

Demand side EMS

・・・

EMS-n

30 minutes plan

ＤＲTarget

EMS-1

Demand side EMS

・・・

EMS-n

Charge/Discharge Control

CEMS functions include 1)development of the basic consumption plan for the area

based on the single demand plan 2) dispatch of the demand reduction based on the requirements of the utility

Verification of the results of incentives (points) mechanism for DR

Cost benefit verification of batteries in demand response program in coordination

with demand side EMS

Energy Management Functions

30 minutes plan

8

Local Voltage Control with Power Electronics Devices

SVR Distributed Generator

L

Building, Factory etc.

Target point

Voltage at SVR

Is=0

G=L=Max

G=L=0

SVR (SVC) can detect only voltage at its location. Voltage at Target point can be strongly

Vs Vc

Vs

Vc？

G

LRT Ｌ

Ｌ

Feeder 2

Feeder 1 Several PV

Voltage

Distance

Upper Limit

Lower Limit

Voltage Feeder 1

Voltage Feeder 2

• Distributed generators affect the distribution network voltage. It is expected an increase of voltage and high fluctuation in the profile.

• Voltage increase can create damage to customers appliances and PV stopping.

- Power electronic devices able to monitor the voltage locally and to supply or absorb reactive power can be a solution to the challenge:

1) LRT (Load Ratio Control Transformer) 2) SVR (Step Voltage Regulator) 3) SVC (Static Var Compensator)

-Location and sizing of the devices are designed using power flow simulation

9

Central Voltage Control

P,Q,V

Central Voltage Control System

LRT

Distribution Line

SVR

Switch Unit

Switch Unit SVR Unit

LRT Unit

Tap Status

Tap Control

P,Q,V

P,Q,V

Distribution Automation System

Switch Unit

Optical Fiber Network

Tap Status

Tap Control

Local controlled devices can help in solving some problems but due to the narrow vision of the network status they may not be sufficient.

Central Voltage Control System:

- Acquisition of several data of the network using sensors installed in the switch.

- Power flow calculation for state estimator of not monitored network points

- Optimal tap control signal for LRT, SVR or reactive power output for SVC based on loss minimization.

- On line control of distribution equipment

10

Japanese Strategic Projects

Project Title Place Objective

Smart Hose Smart House Demonstration Project

Several places

Development and demonstration of technologies for the optimization of electric appliances inside a house

Micro grid

Demonstration tests of the next-generation power Trans./Dist. network for solar power generation

10 island

-Kyushu

-Okinawa

Identification of challenges to be solved before the construction of a next-generation power transmission and distribution network that can cope with the mass introduction of solar power generation in the years to come

Smart City

Demonstration of Next-Generation Energy and Social Systems

4 Cities:

-Yokohama,

-Toyota,

-Kyoto,

-Kitakyushu

Demonstration of a smart community, (regional energy / social systems) that combine in multiple concepts such as the “coordinated use” of energy (electricity heat and untapped energy), the transformation of regional transport systems and people’s lifestyle.

Smart Grid

Project to Substantiate Optimization Control Technology for Next-Generation Electrical Tran./Dist. Systems

Universities A large-scale project featuring participation from a total of 28 entities composed of 3 universities 10 businesses/groups associated with electrical power, and 15 corporations investigating all the aspects of next grid

Source: METI HP/ NEDO HP