DVM - Design Verification Module

LineSurge() Test Objective

The purpose of the LineSurge() test is to determine the converter response to a sudden increase in line voltage amplitude. The input is configured as an AC Line Surge/Sag Input Source, and the output is configured as a Resistive Load. The initial conditions for the simulation are typically found with a FindAcSteadyState() test, which runs a long transient simulation and saves the initial conditions using the GenerateInitFile testplan entry.

The LineSurge() test runs a transient simulation on the converter with timing based on values entered in the Line Surge/Sag tab, which is shown below and accessed from the Full Power Assist DVM control symbol.

This test objective measures the following scalar values:

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Testplan Syntax

The LineSurge() function has the following syntax with the arguments described in the table below:

LineSurge(REF, LINE_RANGE, NOMINAL_VOLTAGE, SURGE_VOLTAGE, FREQUENCY)
LineSurge(REF, LINE_RANGE, NOMINAL_VOLTAGE, SURGE_VOLTAGE, FREQUENCY, OPTIONAL_PARAMETER_STRING)  

Argument Range Description

REF

n/a

The actual reference designator of the DVM Source or the generic syntax of INPUT:n where n is an integer indicating a position in the list of managed DVM sources. 

LINE_RANGE

LL or HL

The line range to select the correct symbolic voltage value. This can only be the two strings LL or HL.

NOMINAL_VOLTAGE

min:0

The RMS voltage for the input source during the normal operating conditions. The voltage can be a numeric value or a symbolic value, such as a percentage of nominal input voltage. Symbolic values use the LINE_RANGE parameter to find the correct symbolic value.

SURGE_VOLTAGE

min:0

The RMS voltage for the input source during the surge event. The voltage can be a numeric value or a symbolic value, such as HL_Surge. Symbolic values use the LINE_RANGE parameter to find the correct symbolic value.

FREQUENCY

min: > 0

The AC line frequency of the input source. This is used to both set the frequency of the input source and to set the simulation timing. The frequency can be a numeric or a symbolic value, such as F_High or F_Low.

OPTIONAL_PARAMETER_STRING

n/a

Parameter string with a combination of one or more timing parameters:

  • NCYCLES_STOP*
  • NCYCLES_DELAY
  • PHASE_ANGLE*
  • LINE_PHASEANGLE*

*    If more than one parameter is specified, join the parameter key-value pairs with a space, as shown in the example below. The order of the parameter names does not matter.

Simulation Timing

DVM sets the timing parameters for the LineSurge() test objective based on values that you enter on the Line Surge/Sag tab of the DVM Full Power Assist control symbol:

Delay Before Surge/Sag, Duration of Surge/Sag, Time to Recover, and Surge/Sag Phase Angle.

In the OPTIONAL_PARAMETER_STRING and in the calculations below, these values are renamed as follows:

The time delay is based on the following conditions and calculations. Typically the LINE_PHASEANGLE is set to 0, although in a 3 phase system only one of the three line sources will have a zero LINE_PHASEANGLE.

If LINE_PHASEANGLE is greater than 0, then

\[ \text{TIME_DELAY} = \frac{360 - \text{LINE_PHASEANGLE}}{360 * \text{FREQUENCY}} + \frac{\text{NCYLES1}}{\text{FREQUENCY}} + \frac{\text{PHASE_ANGLE}}{360 * \text{ FREQUENCY}}  \]

If LINE_PHASEANGLE is less than or equal to 0, then

\[ \text{TIME_DELAY} = \frac{\text{NCYLES1}}{\text{FREQUENCY}} + \frac{\text{PHASE_ANGLE}}{\text{360} * \text{FREQUENCY}}  \]

The pulse width and stop time are based on these calculations:

\[ \text{PULSE_WIDTH} =  \frac{\text{NCYLES2}}{\text{FREQUENCY}} \]

\[ \text{STOP_TIME} = \frac{\text{NCYCLES1} + \text{NCYCLES2} + \text{NCYCLES3}}{\text{FREQUENCY}}\]

A special note about the input voltage source used for this test objective. The slew rate of the input line voltage during the line transitions is limited by the input source. Each AC source has a programmable filter and slew rate limiter - the combination of these two circuits will limit the rate of change of the input line voltage. Of course, if the surge phase angle is set to 0, 180 or 360, there is no instantaneous change in the input voltage, as the line source changes when the line voltage is zero.

Source and Load Subcircuit Configuration

The LineSurge() test objective sets the source and load subcircuits to the following:

Source Control Source (if used) Load

AC Line Surge/Sag Input Source

DC Auxiliary Source

Resistive Load

Loads other than the output under test are set to the Resistive Load. All other sources are set to either the DC Input Source for DC sources or the AC Fixed Input Source for the AC input sources.

Measured Scalar Values

The LineSurge() test objective measures the following scalar values where {load_name} is the name assigned to each load, and {source_name} is the name assigned to each source.

Scalar Name

Description

Frequency({source_name})

A number which represents the line frequency.

V{load_name}%_diff_last_2_linecycles

The percent change in the output voltage when averaged over the last two line cycles.

vout{n}_recovery_time

The time required for the output voltage to reach the output voltage regulation band after the line surge event.
I{source_name} Minimum, Maximum, and RMS values of the source current during the entire simulation time.
I{source_name} After Surge Minimum, Maximum, and RMS values of the source current after the surge event.
I{source_name} During Surge Minimum, Maximum, and RMS values of the source current during the surge event.
I{load_name} Minimum and Maximum values of the load current.
V{source_name} Minimum and Maximum values of the source voltage.
V{source_name} After Surge The RMS voltage of the source after the surge event.
V{source_name} During Surge The RMS voltage of the source during the surge event..
V{load_name} Minimum and Maximum values of the load voltage during the entire simulation time.
V{load_name} After Surge Minimum value of the load voltage after the surge event.
V{load_name} During Surge Maximum value of the load voltage during the surge event.

V{load_name} At Simulation Start Time

The output voltage taken at time=0.

V{load_name} Last LineCycle

The average value of the output voltage during the last line cycle in the simulation. Used for the V{load_name}%_diff_last_2_linecycles calculation.

V{load_name} Previous LineCycle

The average value of the output voltage during the second to the last line cycle in the simulation. Used for the V{load_name}%_diff_last_2_linecycles calculation.

V{load_name} overshoot Maximum value of the load voltage during the surge event.

Measured Specification Values

In the following table, {load_name} is the name assigned to each load, and {source_name} is the name assigned to each source.

Scalar Name

PASS/FAIL Criteria

AC_Settling({load_name})

The percentage change in the output load voltage over the final two line frequency cycles is less than the maximum specification value.

Min_V{load_name}

The minimum value of the output during the simulation time is greater than the minimum specification value.

Max_V{load_name}

The maximum value of the output during the simulation time is less than the maximum specification value.

Max_V{load_name}_overshoot

The maximum overshoot value of the output during the simulation time is less than the overshoot specification value.

Testplan Example

An example of the LineSurge() test objective taken from the AC/DC (1-input/1-output) testplan is shown below. This test objective configures the load to surge between the HL_Maximum and HL_Surge symbolic values. Both values are defined on the Line Surge/Sag tab of the Full Power Assist DVM control symbol. The timing of the line surge event will be determined by the values on the same tab.

*?@ Analysis Objective Source Load Label GenerateInitFile IncludeInitFile
Transient LineSurge(INPUT:1, HL, HL_Maximum, HL_Surge, F_Low)   Load(OUTPUT:1, 100%) Transient|LineSurge|HL_Maximum_to_HL_Surge|F_Low|100% Load   INITFILE_HL_Maximum_F_Low_100% Load

Optional Parameter String

The following LineSurge() test objective uses the OPTIONAL_PARAMETER_STRING argument to set the line voltage to surge between the HL_Maximum and HL_Surge symbolic values and sets the time delay before the surge (NCYLES1) to 2 line cycles, and the surge duration to 10 line cycles.

LineSurge(INPUT:1, HL, HL_Maximum, HL_Surge, F_Low, NCYCLES1=2 NCYCLES2=10)

Test Report

You can view the complete test report in a new browser window here: LineSurge() Test Report. Below is an interactive link to the same test report.

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