ModelingTech Energy Technology uses StarSim Simulation software and NI hardware to build up Micro-Grid real-time simulation system,  which includes a real-time microgrid simulator and a microgrid energy management system controller. The EMS controller and the microgrid simulator use Modbus protocol to communicate with each other.The whole system is shown as below:

Introduction of Microgrid Simulation Model

The micro-grid system includes distributed renewable energy nodes such as solar power, PMSG, and has the VRB energy storage system to support the micro-grid while working under islanded mode. The system load includes ordinal residential load and electric vehicle charging load etc. The topology and the system parameters are referred from the EU benchmark micro-grid system ^[1].

The corresponding relation between the micro-grid system on the real-time simulator and the real microgrid is shown as below:

Functions of Microgrid EMS Controller 

Microgrid EMS mainly realizes the following dispatching and controlling functions:

· The control and switch of two operation modes: grid-connected mode and islanded mode；

· Energy storage system control；

From islanded to grid-connected mode: EMS controls the battery inverter into active synchronization mode, adjusts the microgrid voltage frequency, phase and amplitude to match them to those of the grid voltage, then connects the microgrid to the grid smoothly.

Under grid-connected mode: EMS chooses the charging and discharging mode according to the SOC (state of charge) of battery.

· Management of controllable loads under the islanded mode；

Under islanded mode, when the wind and solar power is insufficient and the microgrid maintains the active power balance by removing the unimportant load.

· Management of voltage support and reactive power under the islanded mode.

EMS uses the droop control algorithm to dispatch and control the reactive power of inverters (PV, wind turbine and energy storage) with the constraints of inverter capacities. 

More Research Areas

The platform is extensible and flexible and the user can do the following research:

· Research on more complex control strategies of microgrid

Such as the load management of the microgrid under random weather conditions, the smooth switching between the grid-connected mode and the islanded mode, etc.

· Research on the simulation and control of power electronics and distributed energy

Such as the SVG, the photovoltaic systems and the electric vehicles.

· Research on the digital-physical co-simulation of microgrid

Combining with the physical hardware and the flexibility of microgrid real-time simulator, the digital-physical co-simulation can accelerate the research.

References

[1]PAPATHANASSIOU S,HATZIARGYRIOU N,STRUNZ K. A benchmark low voltage microgrid network[C], CIGRE Symposium. Athens,Greece,2005:1-5.

Please email info@modeling-tech.com for more information!