13891 photo voltaic power systems and micro grids

8/3/2019 13891 Photo Voltaic Power Systems and Micro Grids

1/23

PhotoVoltaic Power Systems& Micro-Grids, AAU

Tamas Kerekes

Department of Energy Technology

Aalborg University


2/23

PV systems and Micro Grids research programme at Aalborg

University, Department of Energy Technology

Control and design of photovoltaic converters and Micro grid systems with grid connections for

renewable energy systems

2

Members:Remus Teodorescu, Dezso Sra, Tams Kerekes, Erhan Demirok,

Xiaonan Lu, Markos Katsanevakis, Sevnur Eygn

External members Pedro Rodriguez, Marco Liserre, Josep Guererro, Juan Carlos Vasquez

Industrial partners:

Danfoss Solar Inverters, Danfoss Drives, Sunsil, Refu Electronic, Ris,

Eltra, Gamesa Eolica, Enertron, Gaia, Energinet, APC

Partner Universities:

Polytechnic of Bari, Technical University of Catalunia, University of Alcala,

University of Vigo, University of Timisoara, Czech Technical University of

Prague


3/23

PV systems and Micro Grids research programme at Aalborg

University, Department of Energy Technology

Control and design of photovoltaic converters and Micro grid systems with grid connections for

renewable energy systems

Main research areas:

Control strategies for single-phase and three-phase grid-connected PV converters

Grid synchronization and voltage monitoring methods

Islanding detection algorithms

On-line grid impedance estimation for PV inverters

Ride-through capabilities for grid-connected PV converters in case of grid disturbances and faults

Advanced modelling and simulation of grid-connected PV converters (Simulink, PLECS)

Low cost DSP (TMS320F28xx) control implementation

Maximum Power Point Tracking for PV inverters

Modeling and simulation of PV arrays under various athmospheric conditions

Real-time PV simulator for testing grid-connected PV inverters

Characterisations and diagnostics of PV panels

Hardware design of PV inverters

Transformerless PV inverter topologies

Leakage current modeling for transformerless PV inverters (PLECS)

Interaction of Multiple PV inverters with LV network (Matlab, PSCAD)

Voltage control and flexible reactive power sharing (grid supporting and forming) for multiple PV inverters

3


4/23

PV Systems - Main facilities

4

Grid Converters

up to 5A/400V, single-phase or three-phase

with flexible digital control: dSpace DS1103 or TMS320F2812 and

F28335 eZdsp Development board

PV inverter test setup (includes 32kW Dynamic PV simulator,4.5-kW Dynamic Grid Simulator, 3-kW Electronic AC Load, Anti-

islanding Test Setup)

Residential Micro-Grid setup (includes 1.9-kW Polycrystallinesilicone solar panel array, 1.5-kW Danfoss Solar inverter and 1.7-kW

SMA Sunny Boy PV inverters, SMA Sunny island inverter, VRB-ESS5-kW

4h Flow battery, as well as California Instruments 3kW

programmable AC load)

PV-E PVPM 1000C - 1000V/20A photovoltaic I-V curvetracer

for panel/string characterisation

Flashing Solar Simulator Mencke & Tegtmeyer -

240V/16A

for indoor characterisation of PV panels

California Instruments Grid Simulator

for fault simulations

High bandwidth Regatron PV Simulator (includes TopConQuadro Power Supply Module, TC.LIN Linear Post-Processing Unit,

and SASControl PC Software). Output ratings: 32 kW, 1000VDC, 40A


5/23

5

1.8mH

1.8mH

1.8mH

4.7uF

1.8mH

1.8mH

1.8mH

4.7uF

PON109-25a - GPL


6/23

PV Systems - Main activities

Advanced Control for Grid Converters

Control structures

development of the control

structures in different reference frames such as natural

abc, stationary

or synchronously rotating dq for

better matching the application.

Current controllers

different linear (PI, resonant) and

nonlinear (hysteretic, predictive) controllers

Grid synchronization

phase-locked loop (PLL) based

strategies

Grid monitoring

accurate detection of grid voltage

magnitude, frequency and phase angle for fast grid fault

detection. On-line grid impedance estimation.

Ancillary services

voltage support, frequency control,

reactive power compensation, UPS, active filtering, etc.

can be implemented in software.

Control under grid fault

symmetrical currents can be

injected during unsymmetrical grid faults.

6


7/23

Advanced grid voltage and

frequency monitoring for passive

anti-islanding detection

Active anti-islanding methods

based on:

o Harmonic injection

o P,Q variations

o Phase modulation


Software Anti-Islanding of PV Inverters

7


8/23

Improved MPPT optimized for faster tracking andhigher tracking efficiency in cloudy, rapidly

changing conditions, typical to northern Europe

Intelligent MPPT with detection of slow partial

shading caused by fixed obstacles

On-line characterization and performancemonitoring of PV panels by series and shunt

resistance estimation, detection of partial shadows

caused by dirt or reduction of the transparency of

the covering layers as well as rated power

estimation

Model parameter extraction (Rs, Rp, diode qualityfactor) from data-sheet

Cell/connection failures detection


Advanced MPPT and Diagnostics

8


9/23


10/23

Hardware design of:

interleaved DC/DC converter topology for

battery management

DC/DC converter for photovoltaic array

Integrated into a single 3-phase bridge

Energy management for DC coupled micro grids


Integrated multi-function DC/DC converter for PV generation and energystorage for micro grids

10


11/23

Development of new functions for grid-connectedPV inverters to increase their penetration level

Improve LV network power quality by PVinverters (harmonics, fluctuations, unbalance)

Contribution to new LV grid standards regardingPV integration


Control of Grid Interactive PV Inverters

1 2 3 40

5

10

15

OutputPower[kW]

Node number

Injected Power

Curtailed Power

Vo

ltage[V]

Power Generation Profile

245

246

247

248

249

250

251

252

253

Voltage

1 2 3 4-10

-5

0

5

10

15

ActiveandReac

ivePower[kW],[kVA]

Node number

Active Power

Reactive Power

Voltage[V]

ower enera on ro e

235

240

245

250

255

Voltage

Reactive power support

Power curtailment

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12/23


PV Inverter Testing

Advanced high-bandwidth PV simulator

including dynamic irradiation profiles (pulse,

ramp, staircase, custom) and partial shading

Dynamic MPPT efficiency tests dynamic

irradiation profile including sunrise, fast-

and

slow-clouds and sunset

Grid-fault tests

ride-through tests with faulty

grid using grid simulator (sags, short-circuits,

asymmetry, etc.)

Local grid tests

stability and robustness tests

under the conditions of the local grid, including

islanding

Efficiency tests

advanced setup with LabView

interface and 0.02% power accuracy

YOKOGAWA WT3000, PV Simulator with

dSPACE control

European efficiency tests

semi-automated

tests

12


13/23

5kW

4h, 28V Flow-Battery+Island-Grid Inverter

Can switch to the grid for selling

electric energy, or buying if

there is not enough generation

House

3kW Electronic AC load1.5 kW Wind Turbine+ WindyBoy

Inverter1.9 kWp Solar Array

+ PV Inverter

Green Residential Micro Grid Main Components

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14/23

Flow Battery 5kW-4h- no maintenance- 10,000+ deep cycles- high efficiency- full response over temp- nominal charging current

- x2 overloading- ca. 300 USD/kWh

Green Residential Micro Grid Flow battery

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15/23

Green Residential Micro Grid System Configuration

15


16/23

Green Residential Micro Grid Laboratory view

16


17/23

Green Residential Micro Grid On-line monitoring

Monitoring of:

generated wind power

generated solar (PV) power

total power fed into utility network

wind speed

ambient and PV cell temperature

solar irradiation

sampling up to 1Hz

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18/2318

Industrial/Ph.D. Course in "Photovoltaics Power Systems - in theory and practice" by RemusTeodorescu, Aalborg University; Vitezslav Benda, Technical University in Prague; Pedro Rodriguez,Technical University of Catalonia; Dezso Sera and Tamas Kerekes Aalborg University.

Industrial/Ph.D. Course in "Power Electronics for Renewable Energy Systems - in theory andpractice" that will be held at Aalborg University, November 15-17 by Remus Teodorescu, AalborgUniversity; Marco Liserre, Polytechnic of Bari and

Pedro Rodriguez, Technical University of

Catalonia.

Industrial/Ph.D. Course in "Micro-Grids - in theory and practice" by Remus Teodorescu andTamas Kerekes, Aalborg University; Josep Guerrero and Juan C. Vasquez, Technical University ofCatalonia.

PhD/Industrial courses


19/23

Reliable Grid Condition Detection (STVF, Ris, ELTRA) Modelling and control of grid inverter (Gamesa Eolica, Enertron)

Control Development for Residential PV Inverters with Software Anti-Islanding Feature (PSO,

Danfoss Solar A/S)

Gaia Wind Turbine in Wind-Diesel Systems and as Stand-Alone (MITA A/S, GAIA A/S, AAU, RIS,

UVE)

High Efficiency Solar Inverter (AAU, REFU GmbH)

PhD Projects

Control of Grid Interactive PV Inverters (AAU, Danfoss Solar Inverters A/S)

Erhan Demirok

(ongoing)

Analysis and modelling of transformerless PV inverter systems (PSO, Danfoss Solar Inverters A/S) -

Tamas Kerekes (finalised)

Real-time Modelling, Diagnostics and Optimised MPPT for Residential PV Systems (AAU,

PSO/ELTRA) -

Dezso Sera (finalised)

Reliable Grid Condition Detection and Control of Single-phase DPGS (AAU, STVF) -

Mihai Ciobotaru

(finalised)

Monitoring and Advanced Control of Three-Phase Distributed Power Generation System (AAU,

Ris, Eltra) -

Adrian Timbus (finalised)

In addition, Master student projects related to Micro Grids and PV systems are runningcontinuously

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Research collaboration projects


20/2320

Smart Photovoltaic Systems (SPVSYS)

to support the integration of PV systems into the electrical power systems by

proposing new, more intelligent converters that are able to interact with the electrical

environment at their point of connection

-

Smart control of PV systems, by employing new functionalities that prepare PV inverters for the

integration into the smart grids of the future, and help comply with the ever more stringent grid

requirements in an environment where many other PV systems are connected to the same grid.

-

Condition Monitoring and Diagnostics functionalities that monitor the state of the entire PV power

system including the PV array, inverter and grid, and feature effective measures to maximize

availability and reduce maintenance.

Partners:

Aalborg University; Danfoss Solar Inverters A/S; Sunsil A/S; Technical Universityof Catalonia; Technical University of Bari; Technical University

of Warsaw

Future work


21/2321

Questions ?


22/2322

PON107-45 - DRIVES lab

PON109-25a - GPL


23/23

PON107-45 - DRIVES lab

dSPACE system

Danfoss FC302 inverterinterface card

Danfoss FC302 inverter

2.2kW

LEM

modules

DC Power

Supply

PCSimulink with RTW &

dSPACE Control Desk

PWM1

UDC-IM

PWM2

PWM3EN

Danfoss FC302 inverterinterface card

Danfoss FC302 inverter

15kW

LEM

modules

DC Power

Supply

PWM4

PWM5

PWM6EN

DC

IM PM

IRST-IM

UDC-PM

IRST-PM LEM

modulesLEM

modules

DC

13891 photo voltaic power systems and micro grids

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