Select Continuous ( default) to perform a continuous solution of the model.

Select Discrete to perform a discretization of the model. You specify the sample time in the Sample time parameter.

Select Phasor to perform continuous phasor simulation of the model, at the frequency specified by the Frequency (Hz) parameter.

If Simulation type is set to Discrete phasor, you can perform a phasor simulation at fixed time steps specified by the Sample time (s) parameter, at the frequency specified by the Frequency (Hz) parameter. The Discrete phasor solver uses simplified machine models that produce simulation results similar to transient stability software.

Specify the sample time used to discretize the electrical circuit. This parameter is visible only when the Simulation type parameter is set to Discrete or to Discrete phasor.

Set the Sample time parameter to a value greater than 0. The powergui block displays the value of the sample time. The default value is 50e-6 s.

Specify the frequency for performing the phasor simulation of the model. This parameter is enabled only when you set Simulation type to Phasor or to Discrete phasor. The powergui block displays the value of the phasor frequency. The default value is 60 Hz.

Open the Steady-State Voltages and Currents Tool dialog box to display the steady-state voltages and currents of the model. For more information, see power_steadystate.

Open the Initial States Setting Tool dialog box to display and modify initial capacitor voltages and inductor currents of the model. For more information, see power_initstates.

Open the Machine Initialization Tool dialog box to initialize three-phase networks containing three-phase machines so that the simulation starts in steady state. The Machine Initialization tool offers simplified load flow features but can still initialize machine initial currents of your models. For more information, see power_loadflow.

Open the Impedance vs Frequency Measurement Tool dialog box to display the impedance versus frequency defined by the Impedance Measurement blocks. For more information, see power_zmeter.

Open the FFT Analysis Tool dialog box to perform Fourier analysis of signals stored in a structure with time format. For more information, see power_fftscope.

See Performing Harmonic Analysis Using the FFT Tool for an example that uses the FFT Analysis tool .

Open a window to generate the state-space model of your system (if you have Control System Toolbox™ software installed) and open the Linear System Analyzer interface for time and frequency domain responses. For more information, see power_ltiview.

Open a window to design a hysteresis characteristic for the saturable core of the Saturable Transformer block and the Three-Phase Transformer blocks (two- and three-windings). For more information, see power_hysteresis.

Open a window to compute RLC parameters of an overhead transmission line from conductor characteristics and tower geometry. For more information, see power_lineparam.

Open the Generate Report Tool dialog box to generate a report of steady-state variables, initial states, and machine load flow for a model. For more information, see power_report.

Open power_customize to create custom Simscape Electrical Specialized Power Systems blocks.

Open the Load Flow Tool dialog box to perform load flow and initialize three-phase networks and machines so that the simulation starts in steady state.

The Load Flow tool uses the Newton-Raphson method to provide robust and faster convergence solution compared to the Machine Initialization tool.

The Load Flow tool offers most of the functionality of other tools available in the power utility industry. For more information, see power_loadflow.

Defines the maximum number of iterations the Load flow tool iterates until the P and Q powers mismatch at each bus is lower than the PQ tolerance parameter value (in pu/Pbase). The power mismatch is defined as the difference between the net power injected into the bus by generators and loads and the power transmitted on all links leaving that bus. For example, if the base power is 100 MVA and PQ tolerance is set to 1e-4, the maximum power mismatch at all buses does not exceed 0.1 MW or 0.1 Mvar. The default value is 50.

Specify the frequency used by the Load Flow tool to compute the normalized Ybus network admittance matrix of the model and to perform the load flow calculations. The default value is 60 Hz.

Specify the base power used by the Load Flow tool to compute the normalized Ybus network admittance matrix in pu/Pbase and bus base voltages of the model, at the frequency specified by the Load flow frequency parameter.

To avoid a badly conditioned Ybus matrix, select the base power value in the range of nominal powers and loads of the model. For a transmission network with voltages ranging from 120 kV to 765 kV, a 100 MVA base is usually selected. For a distribution network or for a small plant consisting of generators, motors, and loads having a nominal power in the range of hundreds of kilowatts, a 1 MVA base power is better adapted. The default value is 100e6 VA.

Defines the tolerance between P and Q when the Load flow tool stops to iterate. The default value is 0.0001.

Determine the voltage units (V, kV) used by the Load Flow tool to display voltages. The default is kV.

Determine the power units (W, kW, MW) used by the Load Flow tool to display powers. The default is MW.

When this check box is selected, the Simscape Electrical Specialized Power Systems warnings do not display during model analysis and simulation. By default, this option is not selected.

Select to enable the command-line echo messages during model analysis. By default, this option is not selected.

Select to use TLC state-space S-functions (sfun_spssw_contc.tlc and sfun_spssw_discc.tlc) in Accelerator mode and for code generation.

Clear this box if you notice a slowdown in performance when using Accelerator mode, compared to previous releases. This slowdown occurs if you have the LCC compiler installed as the default compiler for building external interface (mex). By default, this option is not selected.

Select this option to model switching devices as current sources. By default, this option is not selected, which corresponds to the recommended setting for most of your applications.

Modeling switches, such as circuit breakers or power electronic devices, as current sources implies that the on-state switch resistance Ron cannot be zero. In this modeling method, the switches cannot be connected in a series with an inductive circuit or with another switch or current source.

This parameter is available only when the Simulation type parameter is set to Continuous.

When this option is enabled, you must add a circuit (R or RC snubber) in parallel with the switches in your model so that their off-state impedance has a finite value. If your real circuit does not use snubbers, or if you want to simulate ideal switches with no snubber, you must at least use resistive snubbers with a high resistance value to introduce a negligible leakage current. The drawback of introducing such high-impedance snubbers is that the large difference between the on-state and the off-state switch impedance produces a stiff state-space model.

Select to disable the snubber devices of the power electronic and breaker blocks in your model. This parameter is enabled only when the Simulation type parameter is set to Continuous and the Disable ideal switching option is cleared. By default, this option is cleared.

Select to disable the internal resistance of switches and power electronic devices and to force the value to zero ohms. This parameter is enabled only when the Simulation type parameter is set to Continuous and the Disable ideal switching option is cleared. By default, this option is cleared.

Select to disable the internal forward voltage of power electronic devices and to force the value to zero volts. This parameter is enabled only if the Simulation type parameter is set to Continuous and if the Disable ideal switching option is cleared. By default, this option is cleared.

Select to display the differential equations of the model in the Diagnostic Viewer when the simulation starts. This parameter is enabled only when the Simulation type parameter is set to Continuous and the Disable ideal switching option is cleared. By default, this option is cleared.

Select this parameter to automatically set the discretization method to Trapezoidal robust in models that contain at least one of the following blocks:

If your model contains none of these blocks, the discretization method is automatically set to Tustin/Backward Euler (TBE). This parameter is available only when the Simulation type parameter is set to Discrete.

Set this parameter to Tustin/Backward Euler (TBE) to simulate the model using a combination of the Tustin and Backward Euler methods.

Set this parameter to Tustin to discretize the electrical model using the Tustin method. If you use this solver, you need to specify the Rs and Cs snubber values to avoid numerical oscillations when the firing pulses are blocked (when the bridge is operating as a rectifier). You can use the following formulas to compute the values of Rs and Cs:

where:

These values are derived from these criteria:

Set this parameter to Backward Euler to discretize the electrical model using the Backward Euler method.

The default is Tustin/Backward Euler (TBE). This parameter is enabled only if you set the Simulation Type parameter to Discrete and the Automatically handle Discrete solver and Advanced tab solver settings of blocks parameter is cleared.

This parameter is enabled only when Discrete solver is set to Tustin. Select to increase simulation speed by enabling the solver to interpolate in discrete models using power electronics. When this option is selected, the solver captures gate transitions of power electronic devices occurring between two sample times, allowing larger sample times (typically 20×) than you use with the standard solvers. For example, simulating a 5 kHz PWM converter with Tustin (no interpolation) or Tustin/Backward Euler normally requires a 1.0 µs sample time (sampling frequency = 200 × PWM frequency) to obtain a good resolution on pulse generation and guarantee accurate results. With interpolation enabled, using a sample time as large as 20 µs executes faster while preserving model accuracy.

When you select this option:

See the power_buck example model to see how interpolation increases accuracy and simulation speed.

This option is enabled when the Interpolate switching events option is selected. The interpolation method computes model outputs at fixed sample times while taking into account switching events that occur between two sample times. The method receives pulses at fixed time steps and computes the time delays of gate signals arriving within each time step. Computing the time delays enables the method to capture the evolution of states at different switching times.

When Use time-stamped gate signals is cleared, the interpolation method computes the time delays of gate signal.

When Use time-stamped gate signals is selected, the block does not compute the time delays of gate signals. You then need to directly provide time-stamped gate signals to the switching devices in your model. See the power_buck example for more information on the concept of time-stamped gate signals in Simscape Electrical Specialized Power Systems switching devices.

The Use time-stamped gate signals parameter is enabled only when you set Simulation type to Discrete, set Solver type to Tustin, and select the Interpolate option. By default, this option is cleared.

Select to increase simulation speed by enabling the solver to store and reuse matrix computation results. This parameter is enabled only when you set Simulation type to Continuous or Discrete. By default, this option is not selected.

Specify the buffer size for saving state-space matrix computations. This parameter is enabled only when you set Simulation type to Discrete, set Solver type to Tustin, and select the Store switching topologies options. The default value is 100 MB.

If you select blocks, initial state values defined in blocks are used for the simulation.

If you select steady, force all initial electrical state values to steady-state values.

If you select zero, force all initial electrical state values to zero.

The default is blocks.

When selected, the Solver tolerance, Maximum number of iterations, and Continue simulation if maximum number of iterations is reached parameters define the discrete solver used for nonlinear iterative elements such as the nonlinear resistor in the Surge Arrester block and nonlinear inductors modelling saturation in the Saturable Transformer block.

This parameter is enabled only when the Simulation type parameter is set to Discrete.

Specify the largest acceptable solver error. Default is 1e-4.

Specify the maximum number of iterations. Iterations stop when the Solver tolerance is achieved. A solution is usually found within 1 to 3 iterations. An error message is returned and simulation stops if a solution is not found when the maximum number of iterations is exceeded. Default is 100.

Select to limit the maximum number of iterations. This parameter is used for real-time applications. Usually, limiting the number of iterations to 2 produces acceptable results.