Inverter Data

Uniquely identifies the equipment item. The program automatically assigns a name, but you can change it, if needed. The name can be up to 16 characters long.

For inverters, the program automatically assigns the names INV-1, INV-2, INV-3, and so on.

The AC bus to which the inverter connects, which must already exist on the one-line. For your reference, the base kV is displayed next to the bus name.

Describes the way the output of the inverter is controlled for IGBT type. The options are:

• Stand Alone: The inverter will supply any amount of required load, just like an AC grid Swing Bus. The specified voltage magnitude (Ctrl kV PU) and angle (Ctrl Angle) will be maintained. You should carefully check the capability (limits) of the inverter.
• Voltage Controlled: This model supplies the specified amount of kW to connected system, keeping the voltage magnitude at specified value (Ctrl kV PU) on the load side bus. There must be a Stand Alone system present when an inverter is operating in Voltage Controlled mode. Specify the kVAR Min and kVAR Max limits for the inverter.
• Const PQ Output: This model supplies the specified amount of kW and kVAR to connected system. There must be a Stand Alone system present when an inverter is operating in Const PQ Output mode. Specify the kVAR Min and kVAR Max limits for the inverter.

For an IGBT inverter only, if the DC voltage on the input to the inverter drops below this value, then the inverter begins stepping its specified kW loading down until the input voltage rises above Min Voltage Threshold.

Note: The power flow will not solve when loading on photovoltaics causes them to experience a severe terminal under-voltage. Therefore, this special control was added so that inverters fed by photovoltaics reduce load when voltage drops below VMP so that photovoltaics are required to supply less power, thus helping the DC voltage on the photovoltaics increase into a range where a power flow solution can be reached.

The default is Linear, indicating the equipment does not produce harmonics. Choosing Harmonic makes the item an harmonic source and makes other fields in this tab available to edit.

Note: For an adjustable frequency drive (AFD), the Load Type is always Harmonic.
For motors, the Load Type is Harmonic if the With Adjustable Frequency Drive (AFD) check box is selected on the Specifications tab of the motor; otherwise, it is always Linear.

Use to set the fundamental amps. The options are as follows:

• Equipment Rating sets Fundm Amps to the equipment rating of the item described in the Specifications tab. 
• User Specified activates the Fundm Amps field, enabling you to specify a value. 

To use fundamental current calculated by power flow, select Calculated from Power Flow in the Summation Fundamental Voltage area of the Harmonics Options > Control dialog box.

Use the spreadsheet to enter the harmonic spectrum produced by this item. You can enter up to 30 different harmonics in each equipment item. In the spreadsheet, enter the Harmonic Number (such as 5 for the 5^th harmonic), the Harmonic Current in percent of the Fundamental Amps, and the Current Angle. By indicating the current angle, you can simulate transformer phase shift effects on rectifiers so appropriate canceling can take place. The harmonic may be integer or non-integer.

Common harmonic spectra may be entered from the device library. For instructions on how to enter your own spectra information, see Harmonics with Spectrum™. After selecting a particular device library spectrum from the Mfr and Type lists, click Import, and that spectrum is entered into the harmonic spreadsheet.