Grid-Following Control | Evaluating Microgrid Control with Simscape Electrical, Part 3

So a control system in an AC electrical power system that directly controls active and/or reactive power set points is referred to as grid-following. A control system on a DC electrical power system that directly controls DC power is referred to as grid- following. An electrical power system cannot have only grid-following control systems. There must be a grid-forming control system that operates in conjunction with the grid following control system.

OK, in this scenario the microgrid is grid-connected and the battery energy storage system operate in grid-following mode. It means that it directly controls the active and reactive power. To run the scenario, we double click on test param block, and select this one from the dropdown menu before simulating the model.

Here we can see the submission result from various power flows in the system. Note that the solar power changes through out the scenario due to the changing in irradiance. At two second, the BESS controller commands reactive power of 400 kilovolt ampere. And at 3.5 seconds, reactive power is reduced to 0. At 4 seconds the battery charging is commanded with a active power reference of 500 kilowatt.

On the left, we can see how the PV duty cycle responds to the changing irradiance. The system remains in NPPT mode throughout this scenario. On the right, we see PV voltage and current. Notw that because voltage is relatively well regulated, PV current tracks irradiance profile.