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Test Beds

India Testbed

Indian Institute of Technology Madras, Chennai, India

Brief About the Testbed:
The layout of the test bed developed in the laboratory is illustrated in Fig. In general, renewable energy-based distributed generation (DG) can be divided into two broad classes. In this figure, the first category belongs to those which generate ac power of variable magnitude and frequency, such as wind energy, tidal waves, micro-turbines, etc. The second category belongs to those which generate dc output, such as PVs, fuel cells, etc. In the figure, this is represented by PV units. In an ideal and practical DG energy park, the two types of generation should be controlled and integrated intelligently. This requires coordination between the generations from various renewable energy sources. From a power electronics point of view, at the primary stage, we require two types of converters, i.e., ac to dc converter and dc to dc converter, with their dc output to a common dc bus. This is indicated by the dc grid in Fig. . This common dc voltage is further converted to ac voltage of desired magnitude and frequency compatible with the ac grid. At this stage, a dc to ac converter is required. However, before connecting this ac output from the dc to ac converter, proper synchronizing and interfacing circuitry are required. In case the conditions are abnormal on the grid side, the microgrid system must be operated in islanded mode.

Fig. An integrated microgrid system with various renewable energy sources and storage units.

Indian Institute of Technology, Roorkee

Brief About the Testbed:

Testbed infrastructure involves:
  • DC microgrid test set-up with HESS, namely lead-acid batteries, lithium-ion batteries and super-capacitor, electronic loads, PV (both rooftop and emulators)
  • AC microgrid test set-up with 2.2 kW wind emulator and 7 kW grid interfaced PV inverter.
  • Further facilities like RTDS, Power amplifiers, OPAL-RT, FPGA-based WAVECT controllers, etc.
Technical Details: Technical details of the Testbed
Part-I (DC-Microgrid)
  • We have realized both utility interfaced and autonomous DC microgrid setups. Utility interfaced DC microgrid aims at reducing the peak power deficit and providing a reliable power supply even in case of a grid failure or during a blackout.
  • Two neighbouring autonomous DC microgrids are interconnected to enhance reliability by increasing virtual storing and discharging capacity when excess power and deficit scenario arises.
Part II (Wind integrated systems)
  • Coordinated voltage control schemes for the IEEE 33 bus distribution system consisting of DSTATCOM, DC Microgrid, wind system, and the OLTC. The objective is to extract maximum work from all the devices and henceforth improve the voltage profile, reactive power reserve, and transient condition of the network. PHIL experimentation is performed to validate the findings.
  • Cost-effective AC-DC hybrid technologies with the wind system as the AC source and PV within DC microgrid as the DC source for enabling power exchange during isolated and grid-connected modes. This also improves the fault ride-through operation using a supercapacitor in the DC Microgrid.

Architecture of the Testbed:

Fig. Laboratory testbed

Fig. Schematic diagram of interconnected DC Microgrids.

Part-III (AC-Microgrid)

Fig. Block diagram of the test setup for studying the interaction of inverters.

Indian Institute of Technology Bhubaneswar

Brief About the Testbed:
A 50 kW microgrid testbed, as shown below, is being set up at our laboratory. The DC side energy sources consist of a 10 kW Solar emulator, a 5 kW Fuel cell emulator, and a 55 kWh Li-ion battery bank. All these DC sources are connected to a DC distribution panel at 380 V. The AC side energy sources consist of a 10 kW synchronous generator, a 10 kW Doubly-fed induction generator-based wind farm, and a 5 kW Permanent magnet synchronous generator-based wind farm. All these sources are connected to an AC distribution panel operating at 3-phase, 415 V, and 50 Hz frequency ratings. This AC bus is connected to the utility grid through a synchronization panel. The bidirectional flow of energy can be carried out by a Bidirectional AC/DC converter of 25 KVA which is connected between the AC and DC bus. All the energy sources except the synchronous generator are having their corresponding power electronics converters configured with FPGA boards to control their outputs. A central monitoring and control system is proposed, which will be able to study the current status of the system, visualize inputs from all the converters as well as send control signals back to the converters to change their outputs accordingly.

The Architecture of the Testbed:

The function of the Battery management system and the bidirectional DC/DC converter is to charge the battery under normal operation as well as discharge and supply to load in case of any contingency. In addition, an Intelligent Transfer switch is proposed which will also be connected between the AC bus and the utility grid. The function of the switch is to disconnect the microgrid from the grid in case of any contingency (e.g. fault) within the microgrid or outside. At that time, the microgrid will work in islanded mode. Also, when the fault is cleared, the switch will reconnect the microgrid with the utility grid and that is called grid-connected mode. The control signal for the switch will also be sent from the central controller. PHIL setup having 7.5kVA linear four-quadrant power amplifier is in process for testing and validation of the microgrid testbed. Its Implementation and HIL testing of control schemes for energy management within hybrid AC/DC microgrid will be done.

Indian Institute of Technology Delhi, India

Brief About the Testbed:

The testbed is developed as the laboratory-scale evaluation testbed for the operation and control of the microgrid. Real-time hardware-in-the-loop (HIL) simulations and Rapid Control Prototyping simulations can be implemented in the experimental setup. The testbed includes real-time simulators like RTDS, OPAL-RT, and Typhoon 602+ that are interfaced with the physical devices according to the requirement of the experiment. The main objective of the testbed is to provide an accurate yet flexible environment for the testing of microgrid operation and control in situations that cannot be tested in the actual power network. Different innovative control strategies can be verified in this testbed with different microgrid architectures.

Some of the testbed configurations included in this report are power management in the DC microgrid, control of Voltage Source Converter Interfaced Standalone IBRs in AC Microgrid, and Protection of grid-tied IBRs.

Architecture of the Testbed:

Fig. Microgrid Testbed.

Fig. Testbed for real-time validation of an Anti-Islanding Protection Scheme of IBRs.

Indian Institute of Technology, Kanpur

Brief About the Test Bed:
As a part of this project, a smart Low Voltage (LV) distribution system test-bed is developed at IIT Kanpur. The objective is to build a test-bed replicating the Indian distribution network, which can be used as a platform to study various challenges and impacts of DER integration on the actual distribution system. The test-bed is fully reconfigurable to realize lab-scale models of any LV distribution system with or without DER integration. The designed test-bed has the capability to interface with various real-time simulators such as Real Time Digital Simulator (RTDS), Typhoon and Opal-RT, etc., and perform Power Hardware In Loop (PHIL) simulations to facilitate system performance studies. Many components of this test-bed are developed by graduate students as a part of their research work.

Fig. Overview of the LV distribution system testbed.

In this article, a holistic view of the complete test-bed facility is provided, and different elements of the test-bed are introduced.The first step to realize the test-bed was to identify various building blocks of the actual distribution system and fabricating their lab-scale models to fit in the test-bed environment. In the designed test-bed, the voltage level is kept similar to the actual system. However, the power rating is scaled down while maintaining the per unit equivalency. A block-level representation of the test-bed is shown in Fig. The descriptions of various components of the test-bed are summarized below.

The Energy and Resources Institute

Brief About the Testbed:

TERI’s Smart Controller Lab provides the state-of-the-art facilities for research in renewable energy integration and battery energy storage technology. It aims at developing innovative, cost-effective, smart and sustainable distributed power solutions for various applications. The lab is equipped with a Grid Simulator, PV Simulator, Battery Simulator and Load Emulator that provide a realistic testing environment.  The testbed has been developed at TERI’s Smart Controller (SC) Laboratory, TERI-Gram to provide experimental facility for integration of various Distributed Energy Resources (DERs) along with energy storage on a common platform.

The objective of the testbed is to conceptualize, design and demonstrate control strategies for clean energy based distributed energy solutions. The broad aim is to develop the proof of concept for integration of Battery Energy Storage System (BESS) at distribution level, energy management system (EMS) and testing the same in the laboratory condition for customizing various battery charge-discharge control algorithms for performing different distribution-level applications. The efficacy of BESS charging/discharging control algorithm for different applications like Distribution Transformer (DT) overload management, energy arbitrage has been tested through Hardware-in-the-Loop (HIL) by interfacing battery simulator, grid simulator and load emulator at TERI Smart controller (SC) Lab testbed. In this regard, TERI has developed a prototype of a grid-tied battery inverter with assistance from IIT Kanpur, which is utilized to interface the battery simulator (having DC output) with the grid simulator. The prototype has been installed at the TERI Smart Controller Lab testbed.
To fulfil this objective, the following works were planned:
  • Modelling of BESS system in MATLAB software.
  • Hardware-in-the-loop (HIL) testing in lab using LabVIEW, National Instruments (NI) CompactRIO (cRIO) controller.
  • Interfacing the battery simulator, grid simulator, load emulator and battery inverter to test the field pilot applications.
  • Testing the charge/discharge control logic of BESS for pilot installations.
Architecture of the Testbed:

Fig. Schematic diagram of lab testbed

Technical Details:
The schematic of TERI Smart Controller Lab testbed is given as Fig. below

Fig. Schematic of interface between real-time controller and lab equipment

Fig. TERI Smart Controller Lab testbed