LCC Verify

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LCC Verify


The verify module supports two types of frequency tests:

1)Line Model Frequency Scan as documented in Benchmark dc51/52.dat. The Line Model Frequency Scan (LMFS) feature of ATP compares the punched electrical model with the exact frequency dependent PI-equivalent as a function of a specified frequency range.

2)Power Frequency Calculation (PFC) of zero and positive short circuit impedances and open circuit reactive line charging, along with mutual zero zequence impedance for multi circuit lines.


Under Circuit specification each phase conductor is listed for which the user should asign a circuit number. The phase order for overhead lines is from the lowest phase number and up as assigned under

Data in the Line/Cable dialog box. For cables the cable with the highest number of conductors and the lowest cable number comes first (rule of sequece, RuleBook XXIII). A circuit number zero means that the conductor will be grounded during the frequency test.


For the LMFS test the user must specify the frequency range (Fmin and Fmax) along with the number

of points per decade for the logarithmic space frequencies. Clicking on OK will result in the generation of a LMFS data case called xVerify.dat and execution of ATP based on the settings of the ATP-Command (Tools|Options/Preferences). The sources are specified in include files called xVerifyZ.dat, xVerifyP.dat, and xVerifyM.dat for the zero, positive and mutual sequence respectively, bases on the specifications under Circuit specification. The individual circuits are tested simultaneously. The receiving ends are all grounded (over 0.1 mOhm) and all sending ends (except the ones with Circuit number zero) attached to current AC sources with 1 amps in amplitude and a phase angle depending on the test. All phase angles for the zero sequence test are zero. The phase angle for conductor number i in the n'th circuit is -360/(i*x) where x is the total number of conductors belonging to that circuit. The mutual coupling works only for 6 phase lines. For one circuit all phase are supplied with zero phase angle sources, while the other circuit the phases of the sending end are open.


The file xVerify.lis produced by ATP is next read and the LMFS_Verify window pops up.

The Use Old Case button will skip the generation of a Line Model Frequency Scan data case and

trace the program directly to the procedure that reads the existing xVerify.lis file.


For the PFC test the user must specify the power frequency and the base voltage level for scaling of the reactive charging. Clicking on OK will result in the generation of a LMFS data case called xVerifyF.dat and execution of ATP based on the settings of the ATP-Command (Tools|Options/Preferences). In this case each circuit is tested individually (all other phases as left open while a specific circuit is tested). In the PFC case the test line model is included with its' lib-file (several times). The file xVerifyF.lis reduced by ATP will for all voltage source contain information about the injected current and power and this information is used to calculate the sequency data.


Go to Overview of line/cable modelling.