VFD

The vfd object models a variable frequency drive (VFD) motor controller.

Sample

object meter {
    phases "ABC";
    name node4;
    nominal_voltage 4200;
}

object vfd {
    from node4;
    to node5;
    object player {
        property desired_motor_speed;
        file ../data_vfd_speedPlayer_delta.player;
        flags DELTAMODE;
    };
    phases "ABC";
}

object load {
    name node5;
    bustype SWING;
    phases "ABC";
    base_power_A 1000;
    base_power_B 1000;
    base_power_C 1000;
    current_pf_A 0.9;
    current_pf_B 0.9;
    current_pf_C 0.9;
    current_fraction_A 1;
    current_fraction_B 1;
    current_fraction_C 1;
    nominal_voltage 4200;
}

VFD Parameters

Properties

vfd objects are derived from link objects, so any parameters of the link object are available as well.

The I/O column indicates whether a property is user-settable input (I), simulation-computed output (O), or both (IO).

Table 1: vfd table 1

Property Name	Type	Unit	I/O	Description
rated_motor_speed	double	1/min	I	Rated speed of the VFD in RPM. Default = 1800 RPM
desired_motor_speed	double	1/min	I	Desired speed of the VFD In ROM. Default = 1800 RPM (max)
motor_poles	double	N/A	I	Number of Motor Poles. Default = 4
rated_output_voltage	double	V	I	Line to Line Voltage - VFD Rated voltage. Default to TO node nominal_voltage
rated_horse_power	double	hp	I	Rated Horse Power of the VFD. Default = 75 HP
nominal_output_frequency	double	Hz	I	Nominal VFD output frequency. Default = 60 Hz
desired_output_frequency	double	Hz	IO	VFD desired output frequency based on the desired RPM
current_output_frequency	double	Hz	IO	VFD currently output frequency
efficiency	double	%	IO	Current VFD efficiency based on the load/VFD output Horsepower
stable_time	double	s	I	Time taken by the VFD to reach desired frequency (based on RPM). Default = 1.45 seconds
vfd_state	enumeration	N/A	IO	Current state of the VFD Valid values: OFF, CHANGING, STEADY_STATE.