Analisis sa Epekto sa Pagsusuri ug Pagpamahay sa Vacuum Arc Chamber sa Pagtaas sa Kahandalan sa mga Vacuum Circuit Breakers

Ang mga vacuum circuit breakers kasagaran gigamit sa mga distribution networks. Tungod kay sila ang core components sa mga power supply equipment, ang ilang performance depende sa capabilities sa vacuum interrupters ug sa mechanical characteristics sa mga circuit breakers (contact opening distance, stroke, pressure, average closing/opening speed, closing bounce time, opening - closing asynchronism, operation times, ug cumulative allowable wear of contacts). Ang duha ka importante para sa reliable operation. Ang vacuum interrupter mao ang “heart” sa circuit breaker; walay high - performance, reliable one, wala gyud ang high - reliability operation. Busa, ang regular detection ug maintenance sa interrupters, pinaagi sa qualitative - quantitative performance assessment, importante para sa safe, stable circuit breaker operation.

1 Performance Indicators of Vacuum Interrupters

Ang vacuum interrupter gisusunod sa hermetic insulation system (enclosure), conductive system, ug shielding system. Ang iyang performance karakterisado sa insulation level (1 - min power - frequency withstand voltage, 1.2/50 impulse withstand voltage), vacuum degree, ug main - circuit DC resistance. Ang accurate detection ug evaluation nanginahanglan og comprehensive testing ug analysis sa mga indicators.

Ang power - frequency withstand voltage method kasagaran gigamit sa on - site insulation testing. Tungod sa mga advances sa testing technology, ang vacuum degree testing nagsugyot ngadto sa mas dako nga application. Apan, ang pipila ka provinces’ “Regulations for Handover and Preventive Tests of Electrical Equipment” wala kini gi-emphasize gamay, pag-ugnayon pa “using fracture withstand voltage as a substitute when detection is unfeasible”. Kini nagresulta sa theoretical ug practical misunderstandings, nagrisk sa management ug technical accidents. I recommend timely regulation revisions para mapalambo ang interrupter performance evaluation system ug ensure ang safe distribution network equipment operation.

1.2 Fault Types of Vacuum Interrupters

Isip participant sa on-site detection, natukod nako nga ang mga faults sa vacuum interrupters adunay duha ka categories:

• Ang explicit faults gitumongan sa shell rupture o bellows damage, resulta na ang air ingress, loss of vacuum sa interrupter, ug communication sa atmosphere.

• Ang implicit faults gitumongan sa gradual decrease sa vacuum degree. Bisag ang interrupter wala sa communication sa atmosphere, ang internal air pressure gibabaw sa allowable value tungod sa manufacturing processes, transportation, installation, o maintenance factors, resulta na ang interrupter wala mosatisfy sa normal breaking capacity. Ang danger sa latent faults labi na taas kon parehas sa explicit faults. Ang decrease sa vacuum degree mograbe affect sa overcurrent breaking capability sa vacuum circuit breaker, magshorten sa service life sa circuit breaker, ug mahimong makaresulta sa switch explosion sa extreme cases.

1.3 Limitations Analysis of Power Frequency Withstand Voltage and Vacuum Degree Testing

Gikan sa perspective sa on-site practical experience:

• Ang power frequency withstand voltage test labi na effective sa detection sa explicit faults ug makapahatagan sa status sa interrupter. Apan, adunay blind spot sa detection sa implicit faults: kon ang vacuum degree adunay range sa 1×10⁻²Pa to 1×10⁻³Pa, ang power frequency withstand voltage test makapasa. Sa panahon na, ang vacuum degree labi na gamay sa safety threshold sa 1.66×10⁻²Pa, ug ang subtle differences wala makadistingihi.

• Ang vacuum degree tester makakuhog sa accurate measurement sa range sa 1×10⁻¹Pa to 1×10⁻⁵Pa, upgrading ang detection sa interrupters gikan sa qualitative analysis hangtod sa quantitative stage. Makapahatagan usab kini sa service life sa vacuum interrupter batas sa change sa vacuum degree sa certain period, providing technical support sa equipment reliability evaluation. Apan, adunay limitations sa testing range: kon gibabaw sa 1×10⁻¹Pa to 1×10⁻⁵Pa, ang proportional relationship sa ion current ug residual gas density (i.e., vacuum degree) gidependi sa vacuum degree tester mag-usab, ug ang accuracy sa test results wala maensure. Lahi na kon ang explicit faults adunay complete leakage (communication sa atmosphere), ang test values labi na close sa normal state, prone sa misjudgment. Ang reason makapahatagan sa gas collision theory: kon ang gas pressure gibabaw, ang molecular density gibabaw, resulta na ang shorter mean free path sa electrons. Bisag ang number sa collisions gibabaw, ang insufficient kinetic energy accumulation sa electrons gibaba sa probability sa gas molecule ionization, causing the instrument to misjudge the vacuum degree as good.

Baton sa on-site detection practice, importante nga ipahibalo nga ang power frequency withstand voltage test dili mahimong ibutang sa side. Kon ang interrupter makapasa sa power frequency withstand voltage test, sigurado nga ang vacuum degree adunay effective range sa tester, ug ang subsequent vacuum degree test results maoy reliable. Busa, ang vacuum degree test ug power frequency withstand voltage test kinahanglan igamit sa combination. Ang duha ka methods complement each other, ug relying solely sa usa ra ka method sa judgment sa status sa interrupter adunay limitations.

1.4 Main Circuit Resistance Test

Sa on-site detection, ang DC voltage drop method gigamit sa main circuit resistance testing, gamit ang tester nga may current nga dili babaw sa 100A. Ang resistance values after handover ug overhaul kinahanglan mosatisfy sa manufacturer's regulations, ug during operation, dili gibabaw sa 1.2 times sa factory value. Kon ang contact wear sa vacuum interrupter mosulti sa poor contact, makadetect kini pinaagi sa circuit resistance testing. Kon ang main circuit resistance dili qualified sa long time, makasulti kini sa overheating sa interrupter, leading sa decline sa insulation performance sa related components ug even short-circuit explosions.

2 Measures to Improve Vacuum Interrupter Reliability

• Regularly carry out vacuum degree testing (combined with 42kV power frequency withstand voltage test) para masulti ang status sa interrupter. Kon ang vacuum degree mobaba, kinahanglan ireplace ang vacuum bubble (most products require replacing three phases simultaneously if one phase is unqualified), ug characteristic tests such as stroke, synchronism, ug bounce kinahanglan matapos.

• Formulate detection cycles baton sa preventive test regulations for electrical equipment ug actual conditions sa unit. Increase monitoring frequency sa first two years after commissioning; recommended to conduct power frequency withstand voltage ug vacuum degree tests sa half a year, 1 year, 1.5 years, ug 2 years after commissioning, then adjust the frequency according to operation conditions after 2 years.

• Reasonably plan maintenance cycles ug inspect interrupters combined with annual preventive tests. After 2,000 normal operations or 10 rated current interruptions, check all parts ug parameters; kon bolts wala loose ug technical parameters meet standards, continue using.

• Regularly test the contact resistance between the two ends of the interrupter ug main circuit terminals para masulti nga wala gibabaw sa specified value.

• When conditions permit, perform infrared imaging temperature measurement sa conductive circuit through the observation hole para track temperature trends. Unqualified main circuit resistance, poor contact, insulation defects, o insufficient heat dissipation gradient due to unreasonable interrupter design can all cause temperature rise sa conductive ug insulating components, leading sa accidents.

• Operation personnel shall regularly patrol the circuit breaker ug pay attention kon may discharge outside the vacuum bubble (discharge usually indicates unqualified vacuum degree testing, requiring timely power outage for replacement). Maintenance key points:

• Check appearance ug wipe dirt

• Replace the vacuum tube kon ang cumulative wear thickness sa moving ug static contacts exceeds 3mm

• Regularly inspect ug adjust contact opening distance, compression stroke, ug three-phase synchronism

3 Conclusions

• Ang power frequency withstand voltage, vacuum degree, ug main circuit DC resistance sa vacuum interrupter importante nga indicators para masulti ang iyang performance, playing a key role sa mastering leakage trends ug estimating service life.

• Ang vacuum degree testing ug power frequency withstand voltage test adunay limitations ug need to be applied in combination para accurately diagnose interrupter reliability.

• The two tests dili mahimo mosubstitute sa usa ra ka lain, ug interrupters failing the tests kinahanglan ireplace, ug it is recommended to revise relevant industry test regulations in a timely manner.

• Improving reliability should start with regular vacuum degree, power frequency withstand voltage, ug main circuit resistance tests, strengthen technical training for operation ug maintenance personnel, conduct careful patrols, infrared temperature measurement, ug scientific detection-maintenance cycle planning para avoid explosions ug other accidents caused by non-electrical misoperations during circuit breaker operation or load switching.