Sendai Microgrid - Introduction and Use Casee2rg.com/microgrid-2012/Sendai_Irie.pdf · Constructed for the purpose of demonstration project ... Microgrid automatically shifts to grid

Copyright (C) Mitsubishi Research Institute, Inc.

Sendai Microgrid

- Introduction and Use Case

July, 2012

Hiroshi Irie (Mr.), Mitsubishi Research Institute, Inc.

1

Outline

Today’s topic - Sendai Microgrid Constructed for the purpose of demonstration project

Still in operation after finishing demonstration project

Has two aspects

MPQM (Multiple Power Quality Microgrid)

Microgrid which supplies electricity in islanded mode – “Earthquake”

Contents

Introduction of Sendai Microgrid

Use Case

What is MPQM, and how it works

Change in configuration after the demonstration project

Earthquake experience of Sendai Microgrid

To be presented by Dr. Hirose after this presentation


By Me

By Dr. Hirose

2 Copyright (C) Mitsubishi Research Institute, Inc.

Sendai Microgrid Overview

3

Sendai Microgrid

Constructed as a 4-year demonstration project (FY 2004 – 2007)

Entrusted by NEDO

Technical feature = MPQM (Multiple Power Quality Microgrid)

Desired power quality varies by customer in the Microgrid.

MPQM enables power supply with different levels of power quality for each

customer within the area.


PV Panels 50 kWp

(IPS) Integrated

Power Supply DVRs

200 kVA 600 kVA

MCFC 250 kW Gas Gen-sets

350 kW X 2

Sendai City

Overview of Sendai Microgrid Geographical location of Sendai City

4

Coverage Area

One connecting point (PCC) with Utility Grid

Divided into 2 areas:

University area

City-owned area


App. 0.5 km (0.3 mile)

High School

Water Plant Facility

Connecting Point with Utility Grid

Cable Routes

Buildings

N

University Zone

City-owned Zone

Energy Center

5

Power Quality Definition and the Loads

Different classes of power quality

In the Sendai Microgrid, five classes of power quality (DC Supply, A, B1, B2 & B3)

have been defined according to each consumer’s needs.


Requirements

CLASS

DC

Power

AC Power

A B1 B2 B3

Interruption NI NI < 15 ms < 15 ms < 15 ms

Voltage Dip Y Y Y Y Y

Outage Y Y Y Y* -

Voltage Fluctuations Y Y - - -

Voltage Harmonics Y Y - - -

Voltage Unbalance N/A Y - - -

Frequency Variation N/A Y - - -

Note. NI: No Interruption, Y: With compensation-: Without compensation,

*: When Gas engine sets generated

Power quality classes of the Sendai Microgrid

CLASS Capacity Consumers (Load)

A 200 kVA Clinic (MRIs)

Laboratory (servers)

B1 20 kVA Nursing Care Facilities

(lighting, PCs)

B2 600 kVA

High School

(lighting, PCs, elevators)

Water plant (induction motors)

B3 200 kVA Nursing Care Facilities

(lighting, clinic equipment)

DC 20 kW Energy Center

(servers, lighting, fans)

Normal N/A

Nursing Care Facilities

Training Center

Dormitories

Power quality classes and Loads

6

System Configuration

Generation Facility

Integrates generation facilities in coordination with power from area EPS

Generation Facilities inside the Microgrid

Two Gas Engines (350kW × 2)

Photovoltaic Generation (50kW)

Fuel Cell (250kW)


DVR*#2

NormalQuality

Load

B3Quality

Load

130 kW700 kW

350 kW350 kW 50 kW

18 kW

6.6 kVac Bus

Point of Common

Coupling PVGE GE

250 kW

MCFC

420 kW

B1Quality

Load

DVR*#1

B2Quality

Load

20 kW180 kW

AQuality

Load

DCQuality

Load

Integrated Power Supply

IPS

200 k

VA

600 k

VA

DGs

PQ

Improvement

Different

PQ Levels’

Loads

Resale Prevention Relay

Key Energy Devices

IPS (Integrated Power Supply)

Provides the highest level of quality

DVR (Dynamic Voltage Restorers)

Compensates Voltage Dip

2 Switches

Point of Common Coupling


Manages islanding operation of the

Microgrid by changing the switch

status to Open or Close in the event

of power outage/recovery.

Configuration of Sendai Microgrid


Use Case -What is MPQM and

How it works

8

Definition of MPQM and Model Simplification

Definition

. The Multi Power Quality Microgrid (MPQM) enables the supply of power to critical loads at multiple levels

of power quality at higher levels than are supplied normally by the distribution utility.

The Microgrid does this by utilizing Distributed Energy Resources (DER) and power from the distribution

utility (grid) in a mutually complementary manner

Functions

The MPQM can continue to supply power at a high power quality level, when grid connected, when the

DER is grid-connected, or when the grid suffers from an outage and the DER is in an islanding operation

mode.

Simplified Model MPQM”:

Focuses on the functionality of “Multiple Power Quality Supply”

Describes the supply of three classes of power quality, as follows:


Class Voltage Dip

Compensation

Waveform

Compensation

Power-failure Compensation

A-Class Compensation

by IPS

Compensation

of waveform.

In case of power outage in grid: DER shifts to islanding operation.

In case of power outage of DER: Power continues to be supplied

from the UPS (battery) embedded in the IPS.

B-Class Compensation

by DVR

No waveform

compensation

In case of power outage in grid: DER shifts to islanding operation.

In case of power outage of DER: No compensation for outage.

Normal

Class

No voltage dip

compensation

No waveform

compensation

No compensation or back up for outage.

9

Configuration of the Simplified Model

Simplified Configuration

The below diagram shows a configuration of the Microgrid offering three classes of

power quality shown in the previous page.


Generation Facility

Microgrid has DERs

Two operational modes

Grid Connection Mode

Islanding Mode

Two Switches

Switch 1

PCC between MPQM and

commercial grid

Switch 2

Boundary point of the

microgrid’s Islanding

Operation Model Configuration

A ClassLoad

A ClassLoad

A ClassLoad

NormalClassLoad

NormalClassLoad

NormalClassLoad

B ClassLoad

B ClassLoad

B ClassLoad

DVR IPS

Grid DERs

Optimized operation between the grid power and DGs

Power Quality

ImprovementNormalQuality

A Class Quality SystemB Class Quality System

SWITCH1SWITCH2

10

Configuration of the Simplified Model (Cont.)

IPS

Able to supply A-Class

Power quality compensation system

with battery storage


Three operational modes:

Grid-Connection Mode

DER-Islanding Mode

Battery-Supply Mode

DVR

Able to supply B-Class

Compensates Voltage dip

Implemented in STATCOM


PV AC Power Source

BatteryACSW

Bypass Circuit

Byp

ass C

ircu

it

50 kWp

DCDC

50 kW 600 Ah

DC Bus

430 Vdc

DCAC

ALoad

B1Load

DCLoad

ACDC

DCDC

300 Vdc

Bidirectional

Converter20 kW

200 kVA

(180 kW)

300 kVA

(270 kW)

3P 400 Vac 3P 200 Vac

IPS System used in Sendai Microgrid

11

MPQM’s Behavior – Four Stages

Four Stages Comprising MPQM’s Behavior

Stage 1: Demand and generation forecast, generation scheduling and on-the-day

review

Develop generation schedule of the Microgrid

Monitor supply-demand status


Stage 2-1：A-CLASS POWER

QUALITY SUPPLY

Supply A-Class loads with A-

Class quality of power.

Stage 2-2：B-CLASS POWER

QUALITY SUPPLY

Supply B-Class loads with B-

Class quality of power.

Stage 3: Automatic shift to

connected operation at grid

restoration

Manage the grid’s outage/

restoration with two switches Four Stages of Function

A ClassLoad

A ClassLoad

A ClassLoad

NormalClassLoad

NormalClassLoad

NormalClassLoad

B ClassLoad

B ClassLoad

B ClassLoad

DVR IPS

Grid Power DGs

NormalQuality

A Class Quality SystemB Class Quality System

SWITCH1SWITCH2

Stage 1

Stage 3

Stage 2-1Stage 2-2

12

Stage 1:

Demand and generation forecast, generation scheduling and on-the-day review

Precondition

Reverse flow from MPQM to Grid is prohibited according to the grid connection agreement

between MPQM owner/operator and the electric utilities.

Therefore, it is required for the Microgrid to set a target for the power flow at the PCC and

incorporate it into the operational plan of DER.


EMS

Demand Archive

DER

1.1:demand record

1.2:demand forecast value1.3: PCC reference1.4:output reference3.1:revised output reference

Customer RTU

2.1:output reference3.2:revised output reference

2.2:demand record

Flow of DER Dispatch

Flow1: Development of generation

schedule

Develop generation schedule

based on the past demand

data, demand forecast and

PCC flow target value.

Flow2: Command and monitoring

Send commands to DER and

also monitor demand data

Flow3: Correction of discrepancy

Change the planned value in

case there is a discrepancy

between supply & demand.

Communication Diagram of Stage 1

13

Stage 2-1：

A-CLASS POWER QUALITY SUPPLY

In the Event of Instantaneous Voltage Dip (Case 1)

IPS shifts into Battery-Supply Mode as it detects an occurrence of instantaneous voltage dip

from the grid voltage.


DER

IPS1:Grid Voltage

Grid

Switch2

2.1:Grid Voltage

EMS

2.2a: Switch 2 signal

2.3: DER-Islanding mode command

2.2b: Switch 2 signal

2.4: DER islanding operation signal

2.5: IPS-DER Islanding mode command

3: DER STOP SIGNAL

In the event of grid outage (Case 2)

Switch 2 automatically

opens as it detects an

outage.

DER shifts to Islanding

mode as it detects the

opening of Switch 2.

EMS sends IPS a

command to shift to

Islanding mode as it

detects the opening

of Switch 2.

IPS shifts into Islanding mode.

In the event of DER stop (Case 3)

IPS shifts into battery supply mode as it

detects the stop of DER. Communication Diagram of Stage 2-1

14

Stage 2-2：

B-CLASS POWER QUALITY SUPPLY

B-Class power quality cannot be supplied when DER is no longer available.

In the event of Instantaneous Voltage Dip (Case 1)

DVR compensates the voltage as it detects an occurrence of instantaneous

voltage dip from the grid voltage.


DER

DVR1:Grid Voltage

Grid

Switch2

2.1:Grid Voltage

2.2: Switch 2 signal

2.3: DER-Islanding mode command

In the event of grid

outage (Case 2)

Switch 2 automatically

opens as it detects an

outage

DER shifts to Islanding

mode as it detects the

opening of Switch 2.

Communication Diagram of Stage 2-2

15

Stage 3:

Automatic shift to connected operation at grid restoration

Microgrid automatically shifts to islanding operation at time of grid outage.

Microgrid automatically shifts to grid connected operation at time of grid restoration.


DER

Switch 11.1b:grid voltage2.1: grid voltage

Grid

Switch2

1.1a:grid voltage

1.2: Switch 2 signal2.5: Switch 2 signal

1.3: DER-Islanding mode command2.3b:islanding system voltage

islanding system frequency2.6: Grid connection mode command

2.2:grid voltagegrid frequency

2.3a:grid voltagegrid frequency

2.4: Switch 2 close operation

Communication Diagram of Stage 3

At time of grid outage (Case 1)

Switch 2 opens as it immediately

detects an outage from the grid

voltage information.

Simultaneously, Switch 1 opens.

DER shifts to Islanding mode as it

detects the opening of Switch 2.

At time of grid restoration (Case 2)

Switch 1 closes as it detects power

restoration from the grid voltage

information.

DER synchronizes the voltage and

frequency of the islanding system

with the grid’s voltage and

frequency.

DER closes Switch 2 as soon as it

detects the synchronization.


Configuration Update After the Demonstration

(Introduction to Hirose-san’s Presentation)

17

Coverage Area of Sendai Microgrid after the Demonstration


Coverage area and configuration of the Sendai Microgrid changed during and after

the demonstration project.

GE is now also used for emergency power generation, starting to supply the C-Class power

to emergency system in (newly-built) hospitals.

Fuel Cell (MCFC) has been removed.

Supply of B2-Class (Sendai High School Water Plant Facility) has been finished.

DVR has been also removed.

Coverage Area During Demonstration

New Hospital Opened- Deriver C-Class

High School



Energy CenterStop electricity Supply to City Owned Zone(B2 Class)High School



N

Energy Center

Coverage Area After

Demonstration

18

Changes in Configuration

Configuration during the demonstration project

DVR*#2

NormalQuality

Load

B3Quality

Load

130 kW700 kW

350 kW350 kW 50 kW

18 kW

6.6 kVac Bus

Point of Common

Coupling PVGE GE

250 kW

MCFC

420 kW

B1Quality

Load

DVR*#1

B2Quality

Load

20 kW180 kW

AQuality

Load

DCQuality

Load


IPS

200 k

VA

600 k

VA


DVR*

#2

NormalQuality

Load

B3Quality

Load

130 kW700 kW

350 kW350 kW 50 kW

18 kW

6.6 kVac Bus

Point of Common

Coupling PVGE GE

B1Quality

Load

20 kW180 kW

AQuality

Load

DCQuality

Load

Integrated

Power Supply

IPS

200 k

VA

C’Quality

Load

SW

170 kW

DVR*

#2

NormalQuality

Load

B3Quality

Load

130 kW700 kW

350 kW350 kW 50 kW

18 kW

6.6 kVac Bus

Point of Common

Coupling PVGE GE

B1Quality

Load

20 kW180 kW

AQuality

Load

DCQuality

Load

Integrated

Power Supply

IPS

200 k

VA

C’Quality

Load

SW

170 kW

Configuration after the demonstration project

There is more B2-Class load.

C’-Class load (supply to new hospital) has been added, instead.


Thank you for your attention! [email protected]

Documents

Sendai Microgrid - Introduction and Use Casee2rg.com/microgrid-2012/Sendai_Irie.pdf · Constructed for the purpose of demonstration project ... Microgrid automatically shifts to grid