Post on 31-Mar-2015
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Monitoring and Operationof PV-Battery Systems
Daniel Föhr, M.Eng.
Product Manger Energy Systems
Q3 Energieelektronik GmbH
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Content
The QBEE Energy System
Determine load profiles
Recording methods and quality of load profiles
Requirements of intelligent PV-battery systems
Advantages of monitoring PV-battery systems
Outlook – From PV to Smart Grid
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QBEE – The Energy System
Maximum usage of own PV energyby minimal purchased power
For new installations
For existing installations
State of the art lithium-ion technology
Compact and powerful
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Setup and components of the QBEE Energy System
1.5 kW bidirectional inverterSuitable for photovoltaic and wind energy with integrated charge controller and energy management
BatteryWith integrated battery management systemwith 2.0 / 4.0 / 8.0 kWh
Grid SensorMonitoring the input and reference power of all thre phases
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QBEE as DC/AC coupled system
Installation as a retrofit for an exisiting system or with an additional PV generator.In this case the battery can be charged via the DC input and/or over the AC connection.
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Determine of load profiles
Determine of the load profile is essential for the battery system layout
The layout of the ideal PV generator and the matching storage capacity for each individual household gets more and more complex
Do not store more than necessary!
Oversized batteries can rarely be exploited
Unused capacity increase costs per kW
The base load capacity determines the storage capacity
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Consumption behaviour
During the day almost never at homeConsumption mainly at night. At daytime long time to charge. High storage potential, no large-scale PV generator needed
Partially workingConsumption is distributed relatively evenly. Tuned mix of PV and Battery
Family with childrenConsumption is highest during the day. Less excess energy available for loading. Large PV generator for natural self-consumption
1
2
3
Consumption behavior can be divided into categories
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Determine of load profiles
QBEE GridSensor
Inductive power measurement of all three phases.
No separation of the lines needed.
Easy DIN rail mounting in the meter cupboard.
Ideal for determining an accurate statement:
One year measurement with a time resolution of 1 second and irradiation data
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Standard load profile
00:0000:45
01:3002:15
03:0003:45
04:3005:15
06:0006:45
07:3008:15
09:0009:45
10:3011:15
12:0012:45
13:3014:15
15:0015:45
16:3017:15
18:0018:45
19:3020:15
21:0021:45
22:3023:15
0
50
100
150
200
250
Standard load profile H0 for households in winter (BDEW)
Mo - Fr Saturday Sunday
Time
Lo
ad
in W
att
s
Example of a standard load profile (H0) with average values of 15 minutes
So
urc
e:
BD
EW
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Individual load profile
Example of an individual load profile with pulsed loads in a temporal resolution of 1 second
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Alternative method – consumption behavior by consumer groups
▪ On the basis of the yearly load consumption a standar load profil is scaled
▪ Merge into main consumer groups
▪ Determine of percentage weighing and tempral distribution
▪ Accuracy of +/- 10%
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Advantages of Monitoring PV-Battery Systems
Requirements:
Fast acting battery system and cell technology
Communication interface between EMS and BMS
Interface for external variables
Interface for Demand Site Management
Bidirectional communication link for external
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Battery System with Forecasting
EMS
BMS
Forecasts
Generator andload models
Load profile forbattery system
Battery model
SOC forecast
Communication interface between EMS and BMS
Weather forecast/Market price prediction
Forecast and determineof load profiles
Optimized operation of battery management
SOC prediction independence on loadprofile forecast
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Dynamic control of EEG regulations
Dynamic 70 or 60%regulation according to the EEG considering:
Entire house load
AC-coupled battery system as an intelligent load
Additional access load
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Demand site management
Excessive energy consumers:e.g. white goods, hot water don‘t need to be supplied by the battery system
Monitoring of PV-Forecast
Deposited load profile
Link with Home Automation
System
Shift consumption in peak
PV production time
Increase natural
self-consumption
Relief of public grid and battery
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Purchase and Sale of Electricity
PV electricity can be offered profitable outside the EEG market regulations.
In combination with battery, monitoring an forecasts:
Determine excess energy/demand
Supply security for the time period
Voltage stability in case of short-term weather changes
PV systems can combine to generate a virtual power plant and use their backup capacity for short term trading at the EEX.
Source: Solarworld
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Offering balancing energy
Based on the monitoring data also unused storage capacity can be identified
Receptive systems can have a positive effect on the grid by providing balancing energy: If they are able to obtain and delivery energy in times of grid overload.
In combination with a bidirectional connection a lucrative market model for the expiring EEG.
E.g. municipal utilities are eagerto regulate their power withintheir own grid.
PV-battery systems can alsoact as a virtual power plant
Source: next-kraftwerke.de
Short term trading with virtual power plants
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Conventional Storage
Conventional storage has no relief effect for the public grid
Maximum feed-ininto the grid
Charge till battery is full
Consumption of PV electricity
Peak production goes directly into the grid
Source: BSW
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Grid optimized charging
Charge when much electricity is generated
Reduced feed-in into the public grid
Low feed-in power increases local grid capacity
Combinded with an PV forecast the battery systems can contribute to:
Regulating the voltage on local low voltage grid
Regulating the frequency in the whole European grid
Source: BSW
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Outlook – From PV to the Smart Grid
PHOTOVOLTAIC
Feed-in
70% Regulation/Load management
Power Balancing/Reactive power control
Supervision & Control
SMART GRID
Intelligent purchase and sale of electricity
Supply of positive and negative control power
Load Management (E-Mobility Devices)
SMART HOME
Energy management
- Energy saving
- Intelligent energy distribution
- Demand site management
Link with Home Automation System
Emergency supply
Hot water preparation
Quelle: www.tret.net
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Q3 Energieelektronik GmbH & Co. KG
Daniel FöhrProduct Manager for Energy Systems
Marktplatz 4888400 BiberachGermany
Mail d.foehr@q3-energieelektronik.deWeb www.q3-energieelektronik.de
Thank you for your attention