The following is a partial list of useful features to give the user an indication of the versatility of **SimuPec:**

- Two power electronics simulators;
**SimuPec**^{® }which is a conventional non fixed admittance simulator and**SimuPec_FA**^{® }the Fixed admittance matrix simulator. - Circuit Partitioning and decoupling (
**for both Simulators SimuPec_FA and SimuPec**) - Interactive and Dynamic Parameters Variation (
**non-fixed admittance Simulator SimuPec only**) - Modeling of Nonlinear and Time Variant Components
- Modular multilevel converter blockset “
**MMC-BLOCKSET**”

**SimuPec**^{®} and **SimuPec_FA**^{®}:

^{®}and

^{®}

**SimuPec**^{® }is a conventional non fixed admittance simulator and **SimuPec_FA**^{® }the Fixed admittance matrix simulator. Both of them^{ }can simulate the same power elecronics system without any modifications of the C-Circuit describtion file.

## Circuit Partitioning and decoupling:

**SimuPec**^{®} and **SimuPecFA**^{® }make use of system-partitioning by dividing the whole large scaled power electronics system containing thousands of switching device, thermal and electromechanical devices into many small sub-systems with different scale of time constants. This leads to remarkable speedup over single system (single very large system matrix).

A single time step delay is needed only if the S-function block needs to communicate with other blocks, for example in the MMC-converter there is no need of any time delay between the S-function blocks of the converter arms because there are no communications needed between each others. Between the S-function block of the converter arms and the main power supply circuit you should add single time step delay.

The figure below shows one MMC-converter station modeled as 7 Simulink blocks. One Simulink block for each arm (half leg) of the converter and one Simulink block for the power supply circuit.

The circuit topoloy of the 6-arms of converter are exsactly the same, they make use the same paramter-vector, however they need different input-vector and deliver different output-vector. Therefor you need to model only one converter arm and use it (copy and paste) for the other converter arms after modification of the respective input-vector and output-vector.

MMC Conveter station modeled as 7 S-function blocks

The basic model of the switching devices by the **fixed admittance Simulator** is a fixed admittance **G=1/ohm** during both switching states; although different values are used in the history source current Vector.

By the **non fixed admittance Simulator,** the basic model of the switching device is a piecewise linear model. The resistance value changes according to the switching state, it takes a very high value (*R _{off}>1e6*) in the turn-off state and a very small value (

*R*) in the turn-on state. The transition between these two states takes place instantaneously

_{on}<1e-3*.*

## Interactive and Dynamic Parameters Variation (**SimuPec only**):

All components parameters can be defined not only as constant values or as elements of the Simulink parameter vector *p[0, 1, 2, …]* but also as elements of the Simulink input vector *u[0, 1, 2, …]*. Components parameters can be interactively changed during the simulation by changing the value of the Simulink parameter vector in the **Simulink** model. They can also be dynamically defined by any **Simulink’s** block via the input vector *u[0, 1, 2, …]*.

The number of basic components offered by **SimuPec **is very small compared to other simulators. There is only e.g. one general purpose Resistor . The same is true for the general purpose inductors, capacitors, voltage and current sources etc. The reason for this is the possibility of dynamic variation of the components parameters.

**Modeling of Nonlinear and Time Variant Components:**

**SimuPec** provide two methods to model nonlinear and time variant circuit components (R, L and C).

- You can use the built-in nonlinear circuit components (R_NL, L_NL and C_NL).
- The nonlinear resistance R_NL is modeled as a current source its value is a function of the voltage on R_NL, either as an equation i=f(v) or in tabular form.
- The nonlinear inductance L_NL is modeled also as a current source its value is a function of the flux linkage ψ of L_NL, either as an equation i=f(ψ) or in tabular form. The flux linkage on L_NL is caculated in simulink by integrating the voltage drop on L_NL.
- The nonlinear capacitance C_NL is modeled as a voltage source its value is a function of electrical charge on C_NL, either as an equation v=f(Q) or in tabular form. The electrical charge on C_NL is caculated in simulink by integrating the current through C_NL.

- You can use the built-in circuit components (R, L and C) and deliver the instantaneous value of the circuit components (R, L and C), depending on the current or voltage of these components, either as equations R=f(v), L=f(i) and C=f(v) or in tabular form.