bidirectional converter application in renewable energy · bidirectional converter application in...

Bidirectional Converter Application

in Renewable Energy

By: Prof. Hamdy Ashour Electrical and Control Engineering Department

Arab Academy for Science &Technology,

Collage of Engineering and Technology, Alexandria, Egypt,

[email protected] & [email protected]

This presentation will highlight on the followings:-

Definition

Utilization within AC Micro-Grid

Utilization within DC Micro-Grid

Utilization within Hybrid Micro-Grid

Typical Topology Examples

Case Study

A lecture by: Prof. Hamdy Ashour

mailto:[email protected]





Bidirectional converter is a power electronics based circuit configuration that can perform the stepping up and stepping down of voltage level with ability of power flow control in both directions.

Bidirectional converters can be used in various applications including Uinterrupted Power Supplies (UPS), Energy Storage System (batteries and fuel cell), Vehicle to Grid (V2G) , and Hybrid Grids with Renewable Energy Resources.

Definition

Power Electronics Converter

(PEC)

Supply (A)

Supply (B)

AC Grid

Fossil Stations

Nuclear Stations

Hydro Stations

Wind Stations

SS

SS

SS

PEC (DC / AC)

DP (DC)

DC Loads

Electrical Vehicles

Storage Units

PEC (AC/ AC)

PEC (AC/ DC)

PEC (AC/ DC)

PEC (AC/ DC)

DP (AC) AC Loads

Solar Stations

SS: Synchronization System

PEC: Power Electronics Converter

DP: Distribution Panels

AC Power Lines

DC Power Lines


Utilization within AC Micro-Grid




AC Power Lines

DC Power Lines

DC Grid

Solar Stations

Fossil Stations

Nuclear Stations

Hydro Stations

Wind Stations

PEC (DC / DC)

DP (DC)

DC Loads

Electrical Vehicles

Storage Units

PEC (AC/ DC)

PEC (DC / DC)

PEC (DC / DC)

DP (AC) AC Loads

PEC (AC / DC)

PEC (AC / DC)

PEC (AC / DC)

PEC (DC/ AC)


Utilization within DC Micro-Grid

AC Grid

Solar Stations

Fossil Stations

Nuclear Stations

Hydro Stations

Wind Stations

AC Loads

SS

SS

SS

DC Loads

Small Wind Units

Small Solar Units

Biodiesel Units

Electrical Vehicles

Storage Units

DC Grid

PEC (AC / AC)

PEC (DC / AC)

DP (AC) DP (DC)

PEC (DC / DC)

PEC (DC / DC)

PEC (AC / DC)

PEC (DC / DC)

PEC (DC / DC)

PEC (AC / DC)


Utilization within Hybrid Micro-Grid




AC Power Lines

DC Power Lines


Typical Topology Examples

Topology of non-isolated bidirectional converter composed of pulse width modulation (PWM) converter and bidirectional buck-boost DC-DC converter

Topology of isolated bidirectional converter composed of pulse width modulation (PWM) converter and bidirectional dual-active-bridge (DAB)

Battery-less Hybrid Micro-grid Power Management Using Bidirectional Three Phase Power Converter

This research work proposes a setup for power flow management over a hybrid grid (including AC and DC grids) using a three phase converter and without need to any permanent storage systems (batteries or fuel cells) on the DC bus to counteract their high cost, complexity of design and integration.

Such proposed system is capable of serving low voltage residential and commercial loads where there would be an availability of renewable energy sources and possible DC loads (heaters, LED lights, electronics, etc …).

Bidirectional power transmission is achieved between AC and DC bus through a three phase converter whose primary objective is to maintain a constant DC bus voltage with respect to DC sources or loads change.

A proportional integral controller is utilized to achieve the reference DC bus voltage by varying the reference AC grid side current which is controlled by a hysteresis controller.

Through Matlab/Simulink simulation and practical implementation, the proposed prototype setup was evaluated for different operation scenarios


Renewable Energy System

DC Micro –Grid Bus AC Micro –Grid Bus

DC Loads AC Loads

PV PEC

Bidirectional

Converter

Mover SG

CB

DSP

Synchronizer &

Power Controller DSP

Power Flow

Controller

V DC

I DC I AC

V AC Gate

Signals

V AC

I AC

f AC

VSG

I SG

f SG

Reactive Active

Trip

Distributed Generation System

Over All System


Proposed Bidirectional Converter Based Setup


Flowchart demonstrating modes of operation

Modes of Operation

The main objective is to eliminate the use of any batteries

or fuel cells, allowing future power level increase on DC bus

with no possible storage requirements and price limitations.

This will require continuous monitoring of DC bus

voltage, since any fluctuations in the DC bus power will

result in direct impact on the DC bus voltage.

To achieve that, three different modes of operation are

provided:-

Mode 1: Inverter mode or current injection to AC grid

that happens when the photo-voltaic (PV) source produces

power (PPV) more than required by DC load, resulting in

potential increase of DC bus voltage.

Mode 2: Rectifier mode or current drawn from AC grid

that happens when the PV source produces power (PPV)

less than required by DC load, resulting in potential

decrease of DC bus voltage.

Mode 3: Off mode, when DC load power is equal to output

DC source power (PPV). A lecture by: Prof. Hamdy Ashour

Simulation Analysis


Proposed hybrid grid simulation ( Using Simulink/ Matlab)

AC grid voltage and current for different operation modes

Mode 1

Mode 3

Mode 2

Experimental Setup

# Description # Description # Description

1 Variable DC power

supply 6

External source for

converter gate power (15 V

adaptors)

11 DC bus voltage

sensor

2 Series DC resistance 7 DSP – Contactors isolation

circuit 12 3-ph AC grid

3 DC bus capacitor 8 DSP 13 DC load

4 3-ph converter 9 3-ph AC grid current

sensors 14

Measuring

devices

5 AC grid side

inductor filter 10 Phase “A” voltage sensor


Experimental Results

Effect of increasing DC load current ( from 0.0A to 2.2A) in the DC grid voltage

(a) without the proposed controller VDC = is decreased from 48V to 15V

(b) with the proposed controller

VDC = is almost constant at 48V


Experimental Results

AC grid voltage (VA) and current(IA) for different operation modes


[1] “Battery-less hybrid micro-grid power management using bi-directional three phase power converter” Mohamed Ismail Nassef, Hamdy Ahmed Ashour and Hussein El Desouki Said ICDCM 2015

[2] “DSP-based simple technique for synchronization of 3-phase alternators with

active and reactive power load sharing” Mohamed Ismail Nassef, Hamdy Ahmed Ashour and Hussein El Desouki Said ICEMC 2016

[3] “Topology of a Bidirectional Converter for Energy Interaction between Electric

Vehicles and the Grid” Jiuchun Jiang , Yan Bao and Le Yi Wang Energies 2014

[4] “A Review of Non-Isolated Bidirectional DC-DC Converters for Energy Storage Systems”

Kostiantyn Tytelmaier, Oleksandr Husev, Oleksandr Veligorskyi and Roman Yershov YSF 2016


Prof. Hamdy Ashour

bidirectional converter application in renewable energy · bidirectional converter application in...

Documents