Constant Impedance Load

The Constant Impedance Load component is located in Microgrid Library. The component icon and its properties window are shown in Table 1. The constant impedance load component represents a three-phase balanced or unbalanced constant impedance load. The possible combinations for the impedance are R, RL series connection, and RC series connection.

Table 1. Constant Impedance Load in the Schematic Editor core library
component	component dialog window	component parameters
Constant Impedence Load		Property tabs: 1 - General 2 - Three-phase 3 - Phase A 4 - Phase B 5 - Phase C

Figure 1. Constant Impedance Load component view under its mask

Tab: "General"

In this tab properties that are applicable to both balanced an unbalanced operation can be set.


Parameter	Code name	Description
Nominal frequency	fn	Nominal grid frequency.
Connection type	conn_type	Combo box that defines the three-phase connection. Options are Y (wye or star) or Δ (delta or triangle) connections.
Enable neutral connection	enable_neutral	By checking this box, an additional port that represents the neutral of a star connection will be added.
Set balanced 3ph power	set_balanced	By checking this field, the power will be balanced. If unchecked, the power can be defined per phase independently.

Tab: "Three-phase"

In this properties tab, power ratings of the load can be defined for balanced load option.

Figure 3. Three-phase properties window tab


Parameter	Code name	Description
Nominal 3ph line voltage	Vn_3ph	Nominal grid line to line voltage.
Nominal 3ph power	Sn_3ph	Desired three phase apparent power to be consumed.
Power factor mode 3ph	pf_mode_3ph	This field allows choosing among lag, lead, or unit power factors (inductive, capacitive or pure resistive load).
Power factor 3ph	pf_3ph	Power factor value applied on chosen power factor mode (when power factor mode is not set to unit).

Tabs: "Phase A", "Phase B", "Phase C" for Y connection

These tabs are used when Set balanced 3ph power is not checked in the General tab. In these tabs you can enter the voltage, power, and power factor per phase. The parameters described here are for Y connection.


Parameter	Code name	Description
Nominal phase voltage (VAn, VBn or VCn)	VAn, VBn or VCn	Nominal line to neutral voltage of the respective phase.
Nominal phase power (SAn, SBn or SCn)	SAn, SBn or SCn	Desired line to neutral apparent power consumed for the respective phase.
Power factor mode	pf_modeA, pf_modeB or pf_modeC	This field allows choosing among lag, lead or unit power factors (inductive, capacitive or pure resistive load) for the respective phase.
Power factor (A, B or C)	pfA, pfB or pfC	Power factor of the respective phase (when power factor mode is not set to unit).

Tabs: "Phase A", "Phase B", "Phase C" for Δ connection

These tabs are used when Set balanced 3ph power is not checked in the General tab. In these tabs you can enter the voltage, power, and power factor per phase. The parameters described here are for Δ connection.


Parameter	Code name	Description
Nominal line voltage (VAB, VBC or VCA)	VAB, VBC or VCA	Nominal line to line voltage between the respective phases.
Nominal line power (SAB, SBC or SCA)	SAB, SBC or SCA	Desired line to line apparent power consumed between the respective phases.
Power factor mode	pf_modeA, pf_modeB or pf_modeC	This field allows choosing among lag, lead or unit power factors (inductive, capacitive or pure resistive load) for the respective phase.
Power factor (A, B or C)	pfA, pfB or pfC	Power factor of the respective phase (when power factor mode is not set to unit).

Example

Overall behavior can be better understood with the use of the given constant impedance load example:

Model name: meter_and_const_z_load.tse

SCADA interface: SCADA_Panel.cus

Path: /examples/models/microgrid/meter_and_constant_z_load/