ac/ dc microgrids

AC/ DC MicroGrids

Introduction

・Problems in the field of electricity and energy after the 2011 earthquake

・Problems of global warming countermeasures

· The continued need for the development of morestable power supply systems due to increased renewable energy.

· A basic energy plan Improvement of consumption efficiencyby 35% by 2030

· Achieving the government goal of Hydrogen society, using IoT

・The expansion of introduction and utilization of renewable energy・To promote energy conservation and reduce greenhouse gas

emissions・The development of energy Management System（EMS）

From large scale centralized typeTo distributed cooperative type

Sponsored by the Aichi Institute of Technology, and the AIT Research project “Development of Hybrid-Power Science & Technology for Green-Energy” (Research Period 2015- )

Now: We are researching the Comfort and Community Green Grid System

MEXT-Supported Program for Collaboration with Local Communities Project “Development of next generation power supply system in micro grid

introduction power system” (Research Period 2006-2010)

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Research on micro / smart grids at Aichi Institute of Technology

MEXT-Supported Program for the Strategic Research Foundation at Private Universities “Creation of solar energy utilization integration technology by nano-material control technology” (Research Period 2010 -2014)

We have been researching into on micro/smart grids as follows

Comfort and Community Green Grid System

In this system, an electric power system mainly based on renewable energy, we aim to build an energy system that saves energy and can provide power to a society without sacrificing comfort and convenience.

Wind power generatorHigh Efficiency Power Generation

and utilization technology

High efficiency power generation of solar power generation equipment

And utilization technology

Peak cut / peak shift technology

Degradation diagnosis of power storage device and technology to extend the life

AC / DC hybrid power supply

Development of EMS

Utilization of fuel cell power generation system

Development of V2H and V2H

Power interchanges at consumers

Development of highly converter

Research on micro / smart grid at Aichi Institute of Technology

Solar power generator



Batteries AC/DC converter

Batteries

Wind turbine

Wind turbine

Wind turbine Micro-Water

turbine

Library

No.12 Building

No.2 Building

Diesel Generators

Aichi Institute of Technology

http://www.ait.ac.jp/facility/research/new-energy/

Our Goal

Project Implementation

Structure

Project items Training engineers and improving technical skills

Construction of green grid by application technology using new energy

“Development of Hybrid-Power Science & Technology for Green-Energy”

Achievement of project

Research Institute for Industrial TechnologyEco-electric research centerGraduate school of engineeringGraduate school of business computer science

CollaborationsCompanies and organizations in Japan and overseasMunicipalities, domestic and international universities

AC/DC MicroGrds in A I T

Operation method of the developed power supply device

Uninterrupted

Voltage・Current Control ?

Islanding mode Connected mode

・System constant power operation・System limited power operation・Peak cut · Peak shift・Reverse tide operation

Connected Mode

Power characteristics

Voltage characteristics

270

280

290

300

310

320

330

340

350

360

370

380

0:00 4:00 8:00 12:00 16:00 20:00 0:00

Volta

ge[V

]

Time[hh:mm]

Const. Power

Power exchange・It is possible to supply power to DC load with reduced loss. ・Energy loss of power exchange can be reduced by the battery and

distributed power connected to the DC system.・The capacity of the possible power exchange does not depend on the

system capacity.

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Power exchange (system configuration)

The figure shows the system configuration when a PFC is used.Between MG 1 and MG 2, PFC is introduced.

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Experimental results using PFC

Conditions of electric power exchange

Eg: MG1：340V MG2：330V MG1⇒MG2MG1：320V MG2：330V MG2⇒MG1

When PFC was used, it was judged only by the DC voltage value of the grid.When the voltage deviates from the set value, power is exchanged.

MG1 MG2

Vbatt_max 336 340

Vbatt_min 330 320

Set voltage of each MG

Name Capacity The number of system

Photovoltaic system 4kW 2

Bi-directional converter

20kVA 2

Storage battery 15.6kWh 2

Load 3kW

PFC 10kW 1

Specification

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Charging/discharging characteristic storage battery

Island modePower interchange

mode

2096.8 1682.5

Decrease of 19.8%

Rechargeable battery charge[Wh]

In case of Island mode In case of Power exchange mode

Power characteristics (MG1)

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Power characteristics (MG2) In case of Island mode In case of Power exchange mode

Charging/discharging characteristic storage battery

Island modePower interchange

mode

280.1 275.6

Decrease of 1.6%

Rechargeable battery charge[Wh]

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DC MicroGrds in Aichi Institute of Technology

We conducted the experiments which used this micro grids

AC power supply system and DC power supply system in LED lighting

Rectifier

LED using AC LED using DC

1

照度計

Experiment environment

AC100V(Dimming rate85%)

AC1 DC2

Volatege [V] 100.2 180.0

Current [A] 0.346 0.169

Power [W] 34.0 30.2

Illuminance [lx] 1152

Efficiency [%] DC2[W]/AC1[W] 88.8

AC200V(Dimming rate85%)

AC1 DC2

Voltage [V] 200.3 180.0

Current [A] 0.172 0.169

Power [W] 33.5 30.2



DC380V(Dimming rate 85%)

DC1 DC2

Voltage [V] 380.3 179.9

Current [A] 0.085 0.166

Power [W] 32.2 29.9



LED lighting using AC / DC Power

DC-LEDはAC-LEDと比較して

2.8%(AC200V)

4.1%(AC100V)

効率が良い

The air conditioner equipment using DC power supply

Solar power panelPmax 70WVoc 20.4VIsc 4.87A

Vpm 15.8VIpm 4.43A

Power Conditioning systemRated power 5.5kW

Rated input voltage DC250VInput operation

voltage range DC0～400V

Rated output voltage AC202±12VRated frequency 50/60Hz

Power factor 0.95

Maximum output power 1.3kWInput operation voltage range DC40～230V

Voltage boost range magnification 1.1～4

Number of circuit 1Power conversion efficiency 98%

Indoor unitRated voltage 100V

Rated frequency 50/60HzRated power consumption of

the electric motor 0.77kWCooling operation current 6.5A

Rated cooling power consumption 0.56kW

Outdoor unitRated voltage 100V

Rated frequency 50/60HzCompressor electrical motor

output 600W

Air Conditioner

DC/DC Converter unit

Specifications

The specifications of each unit used in the aforementioned test system are presented in these tables.

Mode II (with PCS)

Mode III (with PCS )

Mode I(DC power supply)

This system has three operation modes.

Mode I (DC power supply)

This system is a mode which consumes all the outputs of PV by an air-conditioner. When the output of PV is not enough, the power from a grid is used for an air conditioner. When the outputs of PV is enough,we cannot use a power for other equipment.

MPPT control

Experimental of mode I

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Power consumption of the air conditioner>>> AC power supply >>> DC power supply

Photovoltaic Power

Generation

Air Conditioner

AC DCCompressor ～ACDCDC/DCConverter

DCDC

DC power supply mode

AC power supply mode Measurement point of the DC electric powerMeasurement point of the AC electric power

MODEAC

Power （kW)DC

Power (kW)PV

Out put (kW)Room

temperature（℃）Room

humidity（％）Outside

temperature（℃）Outside

humidity（％）

DC 0.01 2.22 2.46 22.4 16.2 5.2 47.3AC 2.35 0.03 0.15 22.3 17.9 5.0 56.1

Performance comparison of AC and DC

Performance comparison of AC and DC

Conclusion■We introduced the AC/DC hybrid-type grid of

Aichi Institute of Technology.

■We developed PFCs to for the experimental model, and the expected operation by certain control has been demonstrated.

■In this presentation, we reported on the demonstration of the basic operation.In the future, we will continue studies for quantification of protective coordination, power supply stabilities, higher efficiency, and cost benefits.

Thank you for your cooperation.

ac/ dc microgrids

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