Here are some options:

1. PSpice Model Library:

• SW/SW_ST: This model represents a simple switch (SW) and a switch with hysteresis (SW_ST). You can set the on-resistance (RON), off-resistance (ROFF), switching time (TON, TOFF), and hysteresis voltage (VH) for the SW_ST model.
• S1: This model represents a controlled switch with a single control voltage. You can define the relationship between the control voltage and the switch state.
• SW_PWM: This model represents a switch driven by a Pulse Width Modulation (PWM) signal. You can specify the PWM frequency, duty cycle, and delay time.

2. SPICE User-Defined Model:

• You can create a SPICE user-defined model to describe the specific characteristics of your fast mechanical switch. This allows you to include details like contact bounce, arcing, and other non-ideal behaviors.

3. External Models:

• Several third-party libraries provide SPICE models for various switches, including fast mechanical switches. Some popular options include:ModelOn!: Offers a wide range of switch models, including SPST, SPDT, and complex switches with multiple contacts. SwCAD: Provides SPICE models for various electromechanical components, including switches, relays, and contactors.

Here are some additional tips for finding the appropriate switch model:

• Identify the specific type of fast mechanical switch used in your hybrid breaker.
• Consult the manufacturer's datasheet for the switch specifications.
• Consider the level of accuracy required for your simulation.
• Look for models that include relevant parameters like switching time, contact bounce, and resistance.
• Test different models and compare the results to validate your simulation.

Here are some resources that may be helpful:

• PSpice Switches: https://www.pspice.com/models/cadence
• EMA Design Automation - How to Create a Switch SPICE Model: https://resources.ema-eda.com/ema-blog/how-to-create-a-switch-spice-model
• ModelOn! SPICE Models: https://modelon.com/
• SwCAD SPICE Models: https://silvaco.com/services/spice-modeling/

Here is an LTSPICE version utilizing the analogy between electrical and mechanical dynamics. I am sure you can convert easily.