Model a 400W HPS Fixture in SPICE



Step 1: Voltage Source

A 3-phase voltage source should be used with a line-to-line voltage of 480V. Use the following syntax:

V_phase1 v1 0 sin(0 480 50)V_phase2 v2 0 sin(120 480 50)V_phase3 v3 0 sin(240 480 50)

Step 2: Resistor

The current model uses a simple resistor, but you might want to add inductance. For a 400W HPS fixture, the operating resistance is typically around 872 ohms:

R_fixture f1 f2 872

Step 3: Inductor (Optional)

HPS fixtures have some inductance due to the magnetic ballast. A real-world model would include an inductor in series with the resistor. A suitable value depends on the fixture's specifications, but a typical range is 1-10mH:

L_fixture f1 f2 5mH

Step 4: Capacitor (Optional)

Some fixtures also have a capacitor in parallel with the lamp to improve power factor. A value of 10-100uF might be appropriate:

C_fixture f2 0 50uF

Step 5: Lamp Model

The lamp itself can be modeled as a voltage-controlled current source. Unfortunately, there is no standard model for a 400W HPS lamp in SPICE. You may need to find a specific model or experiment to determine appropriate parameters.

Example Lamp Model

Subckt lamp i oV_lamp i o {V}R_lamp o 0 10I_lamp o 0 {I_lamp(V)}.model I_lamp(V) VSWITCH(Ron=0.1 Roff=100k).ends lamp

In this example: `V_lamp`: Voltage across the lamp `R_lamp`: Leakage resistance of the lamp `I_lamp`: Current through the lamp, modeled using a voltage-controlled switch (VSWITCH) with a low resistance (Ron) when the voltage is above a certain threshold and a high resistance (Roff) when the voltage is below the threshold.

Adjust the parameters of the lamp model to match the characteristics of your specific 400W HPS lamp.Complete Circuit

Voltage Source

V_phase1 v1 0 sin(0 480 50)V_phase2 v2 0 sin(120 480 50)V_phase3 v3 0 sin(240 480 50)Fixture Model

R_fixture f1 f2 872Inductance (Optional)

L_fixture f1 f2 5mHCapacitance (Optional)

C_fixture f2 0 50uFLamp Model

i v1 0 lamp.param I_lamp(V) = 1.25(exp(V/20) - 1)Circuit Connections

v1 f1v2 f1v3 f1f2 v2

This circuit represents a simplification of a 400W HPS fixture in SPICE. The lamp model is an approximation and should be adjusted according to the specific fixture characteristics. Flag for review