Smart Grid Lab

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Smart Grid Experimental Lab


The Smart Grid experimental Lab accommodates a large number of facilities to allow the simulation, testing and experimentation of Smart micro Grids. A diagram of our experimental setup is shown next:

Diagram of the Experimental Smart Grid

Smart Grid Lab accommodates the following building blocks:

  • SMG Testing switchgear.
  • Power test instruments and systems;
    • SICON Masterys MC UPS 220-380V/80kVA;
    • Programmable DC Power Supply 600V/ 8.5A /5KW;
    • Programmable DC Power Supply, 100V/100A/5000W;
    • Programmable AC Power Source 150V/0-300V/60A/6KVA/45-1000Hz;
    • Programmable AC & DC Electronic Load 4.5kW/45Arms/50V-350V/45-440Hz, DC;
    • Resistive load 3+N/9kW.
  • Renewable energy resources:
    • High temperature PEM fuel cell, up to 2kW;
    • Photovoltaic panels, up to 3kW.
  • Power-line communication:
    • Programmable PLC communication modules implementing the PRIME standard

SMG Testing Switchgear (Pmax=12KW, Imax=55A)


The SMG Testing switchgear is a custom switchgear designed and built to meet, through flexibility and controllability, the needs of a multidisciplinary research activity in residential Smart Grids. The system is composed of three principal sections: an input section, an output section, and a control section. The input section typically realizes the connection of the testing system to the main power source (e.g., off-grid sources like UPS or renewables like PV, fuell-cell, ecc.), while the output section allows to connect the desired loads. Here, naturally, “input” and “output” do not imply any restriction to energy flows, indeed a bidirectional flow of energy is fair. The control section supervises voltages, currents, and temperatures to guarantee the proper and safety operation of the apparatus, moreover it communicates via LAN network the switchgear’s status. The facility is also equipped with a set of cables (for a total length of about 1 km) so that it allows to reproduce typical Smart micro-Grid environments. The lugs of each cable are available at the output section of the switchgear, while at the input section are available the sources’. Hence, through the proper interconnection of cables and systems, a diverse variety of grid configurations can be realized acting on switchgear’s sockets. In these terms, SMG Testing switchgear enable to built and analyze, into the research lab, electrical structures that simulate residential Smart micro-Grids. The special focus is on Smart micro-Grid characteristic distributed and dynamic phenomena, such as intermittent micro-generation, intermittent loads, interferences between smart devices’ communication, and losses.

Switchgear

Renewable Energy Resources


High temperature PEM fuel cell, 100V/100A/2kW DC

A fuel cell is an electrochemical cell that converts chemical energy from a fuel into electric energy. Electricity is generated from the reaction between a fuel supply, in our particular case Hydrogen 3.5 (99.95%), and an oxidizing agent. The reactants flow into the cell, and the reaction products flow out of it, while the electrolyte remains within it. The chose cells are produced by SerEnergy (see http://www.serenergy.dk/) and presents some specific advantages. In fact, the configuration is composed of two independent modules for good test flexibility. Moreover, the HPEM (High Temperature Polymer Electrolyte Membrane) provides compact dimension, solves the Electrode Flooding in PEM, and reduction of Hydrogen consumption. The DC link from the cell is fed into the R&D area where DC/AC system are tested.

Fuel cell diagram:

Fuel Cell System Diagram

Photovoltaic panels, up to 3kW DC

Photovoltaics (PV) is a method of generating electrical power by converting solar radiation into direct current electricity using semiconductors that exhibit the photovoltaic effect. The solar plant is installed in the roof of the main department building (DEI/A). It consists of 15 photovoltaic modules strung together into 4 photovoltaic arrays. The DC link from the arrays is fed into the R&D area where DC/AC systems are tested.

Power Test Instruments and Systems:


Masterys BC

Masterys

Masterys BC is commercially available as an uninterruptible power source for business critical and industrial applications. The SartGrid lab disposes of a modified version of Masterys BC able to fit the particular needs of a research lab. The Masterys’ architecture is shown in the following figure:

 

Masterys ACAC Scheme

 

Its structure is that of a typical UPS, namely, its components are an AC/DC converter, a set of capacitors and batteries, and a DC/AC converter enhanced with a built-in tailored controller unit enabling the user to configure the machine’s behavior. In particular it is possible to define the following aspects of the generated output voltage:

  • RMS output nominal voltage and nominal output frequency;
  • Output voltage periodic swing from a definable minimum rms voltage to a maximum rms voltage, repeated over user defined periods;
  • Add harmonics of arbitrary frequency and RMS voltage to the output;
  • Introduce periodic frequency variations on the fundamental output component;
  • Introduce a jitter in the output waveform;
  • Introduce configurable voltage dips into the output waveform.

Users can execute the setup and configuration procedure via a remote controller (a PC connected to DEI LAN, having  the relevant software installed).

Once properly configured, Masterys will behave, at the output ports, as a three phase ideal voltage source capable of sustaining the defined voltage, through generating or sinking output currents. It can deliver to output loads or absorb and inject back to the power mains up to 64kW of active power. See the technical specifications for further details.

Programmable AC & DC Electronic Load (4.5kW/45Arms/50V-350V/45-440Hz, DC)

The programmable AC & DC electronic load can simulate load conditions under high crest factor and varying power factors with real time compensation even when the voltage waveform is distorted. Its control architecture uses DSP technology to simulate non-linear rectified loads through the particular RLC operation mode. The instrument offers the possibility to route voltage and current signals to an oscilloscope through analog outputs.

Programmable PLC communication modules


Communication over the Smart micro Grid is carried out by exploiting the existing electrical network via power line communications (PLCs). PLCs today offer a reliable, secure, and efficient way to convey information over the grid, at a very reasonable cost. The devices used in the lab are evaluation boards: "Eval ST7590-1SoC" PRIME power line communication kits, which are based upon a narrowband PRIME standard (see http://www.prime-alliance.org). They implement PHY and MAC layer functionalities, and can be externally controlled via a serial interface.

 

programmable PLC communication board