SimPowerSystems

The Continuous Library

The Continuous library contains two types of blocks:

• Current sources simulating continuous machine models, surge arrester, saturable transformer, and distributed parameter lines
• Switching logics used for purely resistive power electronic devices (Breaker, Diode, Thyristor, and Universal Bridge of forced-commutated devices)

  

Nonlinear Blocks Simulated by Current Sources

These blocks use a voltage input (output of the state-space model of the linear circuit) and their current output is fed into the state-space model. For complex models, such as electrical machines requiring several inputs and outputs, vectorized signals are used. Useful internal signals are also returned by most of the models in a m measurement output vector.

For example, the Asynchronous Machine model is stored in the block named asynchronous_machine. The model uses as inputs a vector of four voltages: two rotor voltages (VabR and VbcR) and two stator voltages (VabS and VbcS). It returns a vector of four currents: two rotor currents (IaR and IbR) and two stator currents (IaS and IbS). The model also returns a measurement output vector of 20 signals. When the Asynchronous Machine block is used from powerlib this measurement output vector is accessible through the m output of the machine icon. You can get details on the model inputs and outputs from the documentation of powerlib and powerlib_models block icons.

Logics for Switches and Power Electronic Devices

For switches and power electronic devices, the blocks contain only the logic returning the status (open or closed) of the switch. The switch status is passed to an S-function, which recomputes the state-space model of the linear circuit each time that a switch status is changed. The m output is a vector returning the switch current and voltage. The i output returns the tail current of forced-commutated devices such as IGBTs and GTOs. All the switch logics are vectorized. This means that a single model is used by power2sys to simulate all the devices having the same type.

The Nonlinear Model Library

The Discrete Library