Calculate maximum absolute values of terminal voltage time derivatives (dv/dt) based on logged simulation data
summaryTable = elec_getNodeDvDtSummary(node,tau)
calculates the maximum absolute values of rates-of-change of voltage variables for nodes
that are based on the
summaryTable = elec_getNodeDvDtSummary(
foundation.electrical.electrical domain, based on
logged simulation data. The function returns the data for each terminal in a table. The data
in the table appears in descending order according to the maximum magnitude of the
rate-of-change of voltage variables with respect to the ground, over the whole simulation
time. The table does not contain data for terminals that are held fixed.
Before you call this function, you must have the simulation log variable in your current
workspace. Create the simulation log variable by simulating the model with data logging
turned on, or load a previously saved variable from a file. If
the name of the simulation log variable, then the table contains the data for all the blocks
in the model that have nodes based on the
foundation.electrical.electrical domain. If
is the name of a node in the simulation data tree, then the table contains the data only for
the children of that node.
Examining rates-of-change of voltage variables in power electronics circuits is useful
for determining the potential for unwanted conducted or radiated emissions. The
rate-of-change data also helps you to identify switching devices that might be susceptible
to parasitic turn-on. All nodes that are based on the
foundation.electrical.electrical domain store the potential with
respect to electrical ground as the variable
v. When you log simulation
data, the time-value series for this variable represents the trend of the potential over
time. You can view and plot this data using the Simscape™ Results Explorer.
To evaluate the rates-of-change of voltage variables, the
elec_getNodeDvDtSummary function employs finite difference
approximation of the first derivative with respect to time. It performs 1-D data linear
interpolation of voltage variables using a uniform grid with the time step,
tau. The function then applies the central differencing scheme to the
For small time steps, finite differencing may lead to inaccurate results. The time
tau should be small enough to capture waveforms, but not so
small that the finite differencing error becomes large. For example, for power
transistors with an expected limit of 50 V/ns for their voltage rate-of-change, a
reasonable guess for
tau is 1e-9 s.
Open the Class E DC-DC Converter example model.
This example model has data logging enabled. Run the simulation to create the simulation
simlog_ee_converter_dcdc_class_e in your current
Calculate the maximum absolute values of rates-of-change of voltage variables for the whole model with a time step of 1e-9 seconds, and display the results in a table.
summaryTable = elec_getNodeDvDtSummary(simlog_ee_converter_dcdc_class_e,1e-9)
summaryTable = 19x3 table LoggingNode Terminal max_abs_dvdt ____________________________________________________________________________ ________ ____________ "ee_converter_dcdc_class_e.R_Trans" "n" 3.9473e+10 "ee_converter_dcdc_class_e.Transformer" "p1" 3.9473e+10 "ee_converter_dcdc_class_e.Cs" "n" 3.9457e+10 "ee_converter_dcdc_class_e.R_Trans" "p" 3.9457e+10 "ee_converter_dcdc_class_e.Cs" "p" 3.3499e+10 "ee_converter_dcdc_class_e.LDMOS" "D" 3.3499e+10 "ee_converter_dcdc_class_e.Ls" "n" 3.3499e+10 "ee_converter_dcdc_class_e.Sense_Vds.Voltage_Stress_Sensor" "p" 3.3499e+10 "ee_converter_dcdc_class_e.D2" "p" 6.5621e+09 "ee_converter_dcdc_class_e.Transformer" "n3" 6.5621e+09 "ee_converter_dcdc_class_e.D1" "p" 6.4827e+09 "ee_converter_dcdc_class_e.Transformer" "p2" 6.4827e+09 "ee_converter_dcdc_class_e.Behavioral_Gate_Driver.Controlled_Voltage_Source" "p" 1e+09 "ee_converter_dcdc_class_e.LDMOS" "G" 1e+09 "ee_converter_dcdc_class_e.Cout" "p" 3.0547e+06 "ee_converter_dcdc_class_e.D1" "n" 3.0547e+06 "ee_converter_dcdc_class_e.D2" "n" 3.0547e+06 "ee_converter_dcdc_class_e.R_Load" "p" 3.0547e+06 "ee_converter_dcdc_class_e.Sense_Vout.Voltage_Sensor" "p" 3.0547e+06
The table shows the maximum absolute values over the whole simulation time of voltage
rates-of-change for all the blocks in the model that have nodes based on the
node— Simulation log variable, or a specific node within the simulation log variable
Simulation log workspace variable, or a node within this variable, that contains the
logged model simulation data, specified as a
Node object. You specify
the name of the simulation log variable by using the Workspace variable
name parameter on the Simscape pane of the
Configuration Parameters dialog box. To specify a node within the simulation log
variable, provide the complete path to that node through the simulation data tree,
starting with the top-level variable name.
tau— Time step for numerical differentiation
Time step for numerical differentiation, specified as a real number, in seconds.
tau determines the interpolation grid as
summaryTable— Maximum absolute values of the voltage rates-of-change for each block
Maximum absolute values of the voltage rates-of-change for each block, returned as a
table. The first column lists all the logging nodes in node that are based on the
foundation.electrical.electrical domain. The second column lists
the terminal names. The third column lists the corresponding maximum absolute values of
voltage rates-of-change, in volts per second. The table does not contain data for
terminals that are held fixed.
Not recommended starting in R2019a
elec_getNodeDvDtSummary function will be removed in a future
release. Use the
ee_getNodeDvDtSummary function instead. The only difference between these
functions is the function name. To prevent your code from generating an error when the
function is removed, update to the new function name.