Typhoon HIL Blog


5 grand challenges for Microgrid Controlers that MIT Lincoln Laboratory Microgrid Controller Symposium aims to resolve

Posted by Ivan Celanovic on Feb 10, 2017 3:57:16 PM

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This year at the Microgrid & DER Controller Symposium, organized by the Massachusetts Clean Energy Center and the MIT Lincoln Laboratory, Typhoon HIL will be presenting center stage two live Microgrid HIL Testbed demos using the ultra-high fidelity controller Hardware in the Loop (HIL) interfaced with real industrial controllers.

We will demo both Eaton and GE microgrid controllers, in action, directly interfaced with Microgrid HIL Testbed and controlling a complex microgird controller HIL real-time simulation comprising 3 feeders with 24 busses, one diesel genset, one natural gas genset with combined heat an power, battery storage, PV inverter, and multiple loads running in real-time.

To make it even more interesting, we will be injecting random faults; dispatching DMS requests to microgrid controller to export active/reactive power and to island; blackstarting the microgrid  and all this while monitoring the microgrid “pulse” and measuring and streaming all the performance parameters in real-time.

As we are working with vendors to integrate their controllers with Microgrid HIL Testbed, to put it to the ultimate perfromance test, we are experiencing first-hand how challenging and grueling task it is to commission and test microgrids and microgrid controllers. Even at this day and age.

To complicate things even more, majority of microgrid projects are so called “brownfield” projects that are actually upgrades and retrofits of the existing  power systems.  Getting legacy and new microgrid assets to work together and to communicate in such heterogeneous microgrids is a tall order.

During the microgrid controller design, integration, and comissioning there are five grand challenges, as we see them today, that need to be overcame:

  1. Configuring and testing communications between microgrid controller and DERs-relays
  2. Configuring and testing protection
  3. DER controller configuring and testing
  4. Islanded mode power quality and system stability
  5. Certification of microgrids and microgrid controllers

Without ultra-high fidelity controller HIL simulators, microgrid controller vendors had no other choice than to jump directly from the design phase, to onsite commissioning and testing. When this commissioning is a retrofit job, the project cost and time exponentially explodes.

Controller Hardware in the Loop accelerates testing, commissioning and pre-certifying of microgrids and solves these 5 Grand Microgrid Challenges. Indeed, this what MIT Lincoln Laboratory Microgrid & DER Controller Symposium is demonstrating with Hardware in the Loop HIL Testbed and a spectrum of microgrid controller vendors.

Communications testing

Variety of communications protocols and no clear standardization in the field of microgrid communications requires a significant expertise and time just to get microgrid controller to talk to all the assets. Even when all the nodes talk the same “language,” e.g. Modbus, it takes tremendous amount of time to setup all the right registers, addresses, modes etc.  Now, if you are doing this in the field with limited patience for reading manuals while the DERs are pushing power it is an extremely risky job.

Fortunately, Microgrid Hardware in the Loop simulation provides ultra-high fidelity communication models for different DERs and relays that enable plugging microgrid controller into HIL and configuring communications using virtual device.  Incredible savings in time and money can be realized when this step can be done in a comfort of an office with a desktop HIL directly communicating with microgrid controller.

Protection

Adjusting protection and protection coordination is a complex task, especially for islanded operation and with large penetration of power electronics converters. In addition, more networked topologies that are starting to replace traditional radial networks pose additional set of challenges, including the reconfigurability of network topology.

Controller Hardware in the loop simulation provides a complete environment to test all the protection and protection coordination for all different fault scenarios.  In addition, controller HIL provides a flexibility to start with high-fidelity relay models and then to migrate to testing with real relays in the loop with the simulation.

DER controller configuring and testing

Microgrid projects often need to integrate heterogeneous DERs from different manufacturers into a functional unit. Configuring and tuning inverters and gensets for a particular microgrid architecture can be a daunting task.

Controller Hardware in the Loop simulation where DER controllers are integrated into the testbed enable comfortable configuration and parameter tuning process, without the need to go into the field and perform full power tests.  The time and money savings when this is done in the comfort of an office with a desktop HIL interfaced to microgrid controller and DER controllers are tremendous. Even if particular controller hardware is not integrated into the testbed one can use controller models to tune and test a number of parameters that will be used as a solid starting point in the field.

Power quality and system stability in islanded mode

While microgrid controls in grid-tied operation is challenging, the real test of microgrid controller capabilities is its ability to seamlessly transition from grid-tied to islanded mode and back, and its ability to provide power quality including tight frequency and voltage control. Furthermore, islanded operation is paramount.

Certification of microgrid controllers

While Controller Hardware in the Loop (HIL) pre-certification of inverter based DERs (solar and wind) is burgeoning, microgrid testing is still in its infancy.  In addition, microgrid standardization is in its infancy. IEEE1547.4 is starting to outline good practices and hopefully new revision of IEEE1547 will cover more microgrid standardization the field is still largely uncharted.

The emerging standards for microgrids will require LVRT/HVRT, LFRT/HFRT and grid support functions, similar to DERs, and the only way to systematically test these will be with cHIL. Field testing, for all different microgrid configurations at MegaWatt power levels is just not an option.  Controller Hardware in the Loop will become irreplaceable tool for testing and certification of Microgrids.

 

 

Watch the webinar now Inverter pre-certification for grid codes

 

Topics: Microgrids

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