Grid

The Schematic Editor library block from the Microgrid library, shown in Table 1, models a grid power source.

Table 1. Grid component in the Schematic Editor core library
component	component dialog window	component parameters
Grid		Parameters: Nominal line voltage Nominal frequency Short Circuit power Inductive power factor Execution rate

Grid power stage

The grid power stage consists of a three-phase voltage source, grid inductance with series resistance, and a contactor.

Grid component inputs and outputs

This component has one user interface input and one user interface output. User interface input and user interface output are arrays of 20 elements. Table 2 describes the input signals and their order. Table 3 describes the output signals and their order. All these signals are also defined in the corresponding Grid UI using Probes (for output signals) and Scada inputs (for input signals), as shown in Table 4. Grid UI is located in the same place in the library with the Grid component and it can be unlinked from the library and adopted to your specific needs. The unit [pu] is associated to nominal values, which are inserted as Grid component parameters or derived from them.

Table 2. Grid UI inputs
Number	Input	Description	Input range
0	Connect	A digital input that closes the grid contactor. Contactor is closed when input value is high.	0 or 1
1	Grid_Vrms_cmd	Grid line voltage RMS command. [pu].	> 0
2	Grid_freq_cmd	Grid frequency command. [pu]	> 0
3-19	reserved_ins	Inputs that are not used.

Table 3. Grid UI outputs
Number	Output	Description
0	Connect_fb	Digital signal active when grid contactor is closed.
1	Vrms_meas_kV	An analog output with the RMS value of measured grid voltage. [kV]
2	Fmeas_Hz	An analog output with the value of the measured grid voltage frequency. [Hz]. *Note: Limited by the internal PLL to the range [0.5, 1.5] pu
3	Pmeas_kW	An analog output with the instantaneous value of active power output of the grid. [kW]
4	Qmeas_kVAr	An analog output with the instantaneous value of reactive power output of the grid. [kVAr]
5	Smeas_kVA	An analog output with the instantaneous value of apparent power output of the grid. [kVA]
6	PFmeas	An analog output with value of the grid power factor.
7-19	reserved_outs	Outputs that are not used.

Table 4. Grid UI
Grid UI	Grid UI internals

Grid component mask and parameters

Grid component mask consists of one tab for specifying parameters of the component.

Table 5. Grid component parameters description
Parameter	Code name	Description
Nominal line voltage	Vb	Grid nominal line voltage. [V]
Nominal frequency	f	Grid nominal frequency. [Hz]
Short Circuit power	Sb	Grid short circuit power. It determines the grid impedance value. [VA]
Inductive power factor	pf	Grid power factor when grid is short-circuited. It determines the resistance to reactance ratio.
Execution rate	Tfast	Execution rate of the internal signal processing. [s]

Example

Overall behavior and control methodologies can be better understood with the use of the given example:

Model name: pv_plant_gen.tse

SCADA interface: SCADA_Panel.cus

Path: /examples/models/microgrid/pv_plant/pv_plant (generic)