arrester test

	general
	scope mode
	Reference voltage measuring
	Residual Voltage
	Long Duration Current impulse withstand test

	rectangular impulse current
	energy calculation
	operation duty test

 

general

The described programs arrester test don’t belong to the usual delivery of the software. If you have interests or need this parts of the software, you can purchase them if you contact the manufacturer or your appropriate representative.

For arrester test please select the application "arrester test".  

• Before you are starts with the tests, please create a new project (<F1> or  file, project select/create .. )

• Second select the special test setup for the different test methods, check or change the divider ratios, shunts and the measuring ranges.

• Third start the test  (<F8>  or click bottom start record )

After started the digital recorder the system waiting for the signal. If the signal is recorded the software automatically calculates all selected values. 

It is possible to save this data and to print out a hole protocol with the protocol function (<F3> or protocol )

Parallel to the normal measuring it is possible to use the scope. To start the scope mode please press Shift F9 button <^F9> or .

The scope runs in a own thread and reads direct the values from the analog digital converter. With this method you use a fixed  sampling rate from approximately 15 kS/s depends of the digital recorder system. 

description of scope results table 2:

typically shows the scope two channels the channel 3 and channel 4.  

The auto range function you starts with the bottom . This function tries  to  select automatically a range with a signal level between 80 and 90% of the available range. With the start or stop bottom you could start or stop the scope function.

The scope we use for the reference voltage measuring, long time AC tests and for controlling the AC-generator

Info:

The SCOPE  we are using for controlling the current impulse  generator e.g. from Highvolt, Dresden. A specially Highvolt software communicates with the WinTRAS systems via OLE - Interface. Reading the Scope results from table 2 and controls the impulse current generator. For long time test about more the 24 h, the special software reads every minute the values and write the results in a excel table. Or alternative it is possible with a special WinTRAS function to create a curve only from the peak values.

 

Reference voltage measuring

With the  SCOPE  the reference voltage would be measured. Select the test setup (default: RefVolt)  

typical settings

Channel	type of signal	signal level	sampling rate	displayed time	evaluation type
1	not used				no evaluation
2	not used				no evaluation
3	AC voltage	1..20  kV	600  kS/s	0.1 s	AC from 10 to 100ms
4	AC current	0.5-10  mA	600  kS/s	0.1 s	AC from 10 to 100ms

Reference voltage

The curve and the results are saved with the save button <F5>.  

 

Residual Voltage

Select the test setup (default: ResVolt)   

Example for the setting.

Channel	type of signal	signal level	sampling rate	displayed time	evaluation type
1	voltage impulse	5-100 kV	60 MS/s	20 µs	PK peak value
2	current impulse	0.1-60 kA	60 MS/s	20 µs	IC impulse current
3					no evaluation
4					no evaluation

Long duration current

For long duration test select your test setup, start the scope <shift F9> (or )  and start the test with <F8> (or  )

Default test setup: LDC.:    

Example for the setting.

Channel	type of signal	signal level	sampling rate	displayed time	evaluation type
1	voltage impulse	up to 100 kV	60 MS/s	20 µs	PK peak value
2	current impulse	up to 103 kA	60 MS/s	20 µs	REC rectangular
3					no evaluation
4					no evaluation

For this test the customer could create a new own test setup with his dividers, shunts measuring ranges...

Long Duration Current (LDC)

The rectangular and the energy calculation see the next points.  

rectangular impulse current

According to the IEC  the energy would be calculated with trapezium formula:  W=Up*Ip*Td.

description	definition
W	energy
Up	peak voltage of channel
Ip	peak current voltage
Td	time duration  where the amplitude of the Impulse is greater than 90% of its peak value
Tt	time duration  where the amplitude of the Impulse is greater than 10% of its peak value
Tz	duration time from virtual zero to the first cross with zero line
tmin	is the begin of integral interval
tmax	is the end of integral interval

If search automatic integration interval (tmin to tmax) is selected the software searched the tmax point. 

The software tries to find following points.

•            Tz   (cross with  0% level )
             T10 (cross with 10% level,  Tt  )
             T30 (cross with 30% level,  Tie30 ) 
             T50 (cross with 50% level,  T2 )  
             T70 (cross with 70% level,   Tie70)

  The first point which is found is the tmax time

   If search automatic integration interval (tmin to tmax) is not selected  it is possible to select different evaluation  points.

energy calculation

according to IEC

WinTRAS evaluation settings:

Ch1 [u(t)] evaluated with PK (peak value)

Ch2 [i(t)] evaluated with REC (rectangular, automatic calculated tmin to tmax)

WinTRAS formula without integral:   W=CH1_Up*CH2_Ip*CH2_Td

or                                            W=CH1_Up*CH2_Ip*(CH2_tmax-CH2_tmin)

tmin to tmax is the time in which the amplitude is greater then 0% of the peak value. 

If found automatic integration interval is on, the software tries to found the impulse end.

WinTRAS evaluation settings:

 Ch1 [u(t)] evaluated with PK (peak value)

 Ch2 [i(t)] evaluated with REC (rectangular, automatic calculated tmin to tmax)

 Ch5 = Ch1[u(t)]  * Ch2[i(t)]

 WinTRAS  formula:   W[VAs] = INTEGRAL(CH5,CH2_tmin,CH2_tmax)

To make a operating duty test please select a special test setup as default we delivered "ODT"  setup.

These are test which service conditions are simulated by the application to the arrester of a stipulated number of specified impulses in combnation with energization by a power supply of specified voltage and frequency.

The main requirement to pass these test is that the arrester is able to cool down during the power frequency voltage application., i.e thermal runaway does not occur. It is required therefore  that the arrester section tested shall have both a transient and a steady state heat dissipation capability equal to or less than for the complete arrester, see IEC 6099-4/ 7.5.1.

example operating duty test

measuring channels are in table 1 e.g.:    

Channel	type of signal	signal level	sampling rate	displayed time	evaluation type
1	voltage impulse	16,5 kV	60 MS/s	20 µs	PK peak value
2	current impulse	103  kA	60 MS/s	20 µs	IC impulse current
3	AC voltage	7,85 kV	5   kS/s	20 s	AC from 1 to 5s
4	AC current	30   mA	5   kS/s	20 s	AC from 1 to 5s

For this test the customer could create a new own test setup with his dividers, shunts measuring ranges i.e..

Operating duty test  1998 in Bangalore by CPRI with a 4 channels measuring system. 3 channels with 100 MS/s and one channel with 200MS/s an 10 Bits. 

 We recorded this curve 1998 during input into operation in India. This was our first arrester test system. The documentation shows the higher AC voltage witch was switched on after 100 ms for 10s. The cuurent doesn't increase that means that the arrester is stable. 

Whit  the current and the voltage AC signals it is possible to calculate the (cos φ) and the harmonics.

The delayed switch on of the voltage you need to secure the current shunts.

To measure according the IEC you need a 4 channel measuring system with a minimum sampling rate of 60MS/s and 10 Bit. .

It is possible to measure 30 sec with the digital recorder. If you want measure a longer time (e.g. 1000h see IEC) you can use the implemented scope (see capture 2).

Operating duty test  2002 in Korea by KERI with a 4 channels measuring system. All 4 channels with 60 MS/s and 10 Bit.

time	Upeak/Sqr2	Ueff	Ipeak/Sqr2	Ieff	Ipreal	Preal
	[kV]	[kV]]	[mA]	[mA]	[mA]	[W]
19:03:07	11,99	11,77	12,07	11,89	11,01	80,69
19:03:08	11,96	11,92	11,93	11,77	10,86	83,81
19:03:09	11,93	11,90	11,84	11,73	10,54	82,21
19:03:10	11,94	11,85	11,90	11,77	10,86	81,34
19:03:11	11,96	11,65	11,90	11,56	10,86	78,92
19:03:12	11,96	11,76	11,81	11,70	10,23	81,09
19:03:13	11,98	11,82	11,84	11,75	11,17	82,17
19:03:14	11,94	11,76	11,81	11,60	11,79	81,56
19:03:15	11,95	11,78	11,85	11,73	11,01	81,80
19:03:16	9,97	9,85	9,70	9,69	8,36	55,69
19:03:17	9,94	9,80	9,82	9,67	8,36	55,18
19:03:18	9,96	9,85	9,80	9,60	8,36	55,95
19:03:19	9,94	9,82	9,74	9,66	8,83	55,56
19:03:20	9,94	9,71	9,75	9,71	8,36	56,94
19:03:21	9,94	9,83	9,76	9,63	7,89	55,62
19:03:22	9,94	9,83	9,76	9,63	7,89	55,62
19:03:23	9,95	9,82	9,79	9,63	8,04	55,38
19:03:24	9,98	9,80	9,85	9,68	8,36	56,95
19:03:25	9,96	9,67	10,08	9,68	9,45	53,24
19:03:26	9,98	9,80	9,87	9,55	8,98	55,05
19:03:27	9,97	10,23	9,89	9,46	8,20	51,59
19:03:28	9,97	9,82	9,85	9,75	8,67	55,55
19:03:29	9,97	9,86	9,93	9,72	9,45	56,57
19:03:30	9,96	9,80	9,94	9,68	8,20	55,21
19:03:31	9,96	9,82	9,84	9,68	9,45	55,44
19:03:32	9,95	9,83	9,81	9,89	8,51	56,04
19:03:33	9,95	9,89	9,97	10,07	8,98	56,86
19:03:34	9,94	9,78	9,80	9,63	8,67	54,72
19:03:35	9,96	9,79	9,97	9,65	8,98	55,21