Mfano wa Kufanya na Mada Muhimu za Huduma ya Kitambulisho cha 10kV High-Voltage Reactive Power Compensation

Kitu cha kuzuia uwezo wa nguvu ya miguu au kumpeleka katika mfumo wa umeme wa kiwango cha juu ni muhimu na halisi sana katika mifumo ya umeme ya kisasa. Kwa kutoa au kupata uwezo wa miguu, huchukua matatizo kama upo mkato wa nguvu ndogo, gharama za mzunguko ya miguu kubwa, na mabadiliko ya mshindo kutokana na hitaji wa uwezo wa miguu, ikifanya kazi muhimu ya kuboresha uchumi, usalama, na ubora wa umeme wa mzunguko. Kitu cha kuzuia uwezo wa miguu cha kiwango cha juu 10kV ni kitu muhimu cha kuhakikisha usalama na uchumi wa mzunguko wa umeme.

Kuelewa kanuni zake za kufanya kazi ni msingi wa huduma, na kutekeleza mpango wa huduma wa kila wakati unaojumuisha majaribio ya kusaidia na uzito wa hali—na kudhihirisha usalama—ni jambo la msingi la kuhakikisha uendeshaji wa imani kwa muda mrefu. Kazi ya huduma lazima ifanyike na watu wenye ujuzi na tajriba kulingana na namba zilizotengenezwa. Hapa kuna maelezo kamili kuhusu kanuni za kufanya kazi na asasi muhimu za kuzuia uwezo wa miguu 10kV.

1. Kanuni za Kufanya Kazi za Kitu cha Kuzuia Uwezo wa Miguu 10kV

Mafunzo Yake: Kuboresha ukato wa nguvu wa mzunguko, kupunguza gharama za mzunguko, kuimarisha mshindo wa mfumo, na kuboresha ubora wa umeme.

1.1 Kanuni za Kuzuia Uwezo

• Chanzo cha Uwezo wa Miguu: Nguzo za kushuka katika mzunguko wa umeme (kama vile magari, transformers) huhitaji kukagua magnetic field wakati wa kufanya kazi, kuchukua uwezo wa miguu unaofuata (Q).

• Njia ya Kuzuia: Maeneo ya capacitors yanayounganishwa kwa pamoja, kujenga uwezo wa miguu unaofuata (Qc) ili kukata uwezo wa miguu unaofuata (Ql).

• Matokeo: Uwezo wa miguu (Q) unazopaswa kwa mfumo unapungua, ukato wa nguvu (Cosφ = P / S) unaboreshwa, na nguvu ya kuonekana (S) inapungua.

1.2 Vyanzo vya Kitu cha Kuzuia

• Banki ya Capacitor ya Kiwango cha Juu: Ni chanzo muhimu cha kutoa uwezo wa miguu. Mara nyingi inajumuisha viwanja vingine vya capacitors vilivyounganishwa kwa pamoja na kwa mstari kufikia kiwango cha 10kV na maelezo ya nguvu.

• Reactor:

• Reactor wa Kupunguza Nguvu: Hukipunguza current ya kuanza wakati wa kuswitch capacitors (mara nyingi mara 5–20 za rated current), kuhifadhi capacitors na vyombo vya kuswitch.

• Reactor wa Filtra: Huunda LC tuned circuit na capacitor (mara nyingi tunedi chini ya harmonic frequency ya 5th, 7th, au specific), kuhifadhi harmonic currents kutoka kuingia kwenye capacitor, kuzuia harmonic amplification na resonance, kuhifadhi capacitor.

• Vyombo vya Kuswitch ya Kiwango cha Juu:

• Vacuum Contactor au Vacuum Circuit Breaker: Inatumika kuswitch capacitors banki ina au out. Vacuum contactors zinatumika zaidi na zinafai kwa operations zenye mara nyingi.

• Isolating Switch / Grounding Switch: Inatumika wakati wa huduma kuhifadhi chanzo cha nguvu na kuhakikisha grounding sahihi kwa usalama.

• Kitu cha Kusafisha:

• Coil ya Kusafisha au Resistor ya Kusafisha: Baada ya kuswitch capacitors banki, hukusafisha charge iliyohifadhiwa kwenye terminals za capacitor (mara nyingi inahitaji kupunguza residual voltage chini ya 50V ndani ya sekunde 5), kuhakikisha usalama wakati wa huduma. Coils za kusafisha zinatumika zaidi.

• Vyombo vya Kuhifadhi:

• Fuse: Huhifadhi capacitors individual dhidi ya faults za ndani (expulsion-type fuse).

• Relay Protection: Inajumuisha overcurrent protection (phase-to-phase short circuit), unbalance protection (breakdown ya capacitor element internal au fuse blowout), overvoltage protection, undervoltage protection, harmonic overlimit protection, open-delta voltage protection, na kadhalika.

• Vyombo vya Measurement na Control:

• Controller: Hukiondoa muda mrefu mazingira ya system voltage, current, power factor, harmonic current, harmonic voltage distortion rate, na mengine. Hucontrol automatic switching ya capacitors banki kulingana na strategies zilizopreset (kama vile target power factor, target voltage, harmonic over-limit protection, time-based programs).

• Current Transformer (CT), Voltage Transformer (PT): Hutoa signals kwa measurement na protection.

1.3 Mzunguko wa Kazi

• Monitoring: Controller hukiondoa muda mrefu parameters kama power factor, voltage, na demand ya uwezo wa miguu wa mzunguko.

• Decision: Wakati power factor anapungua chini ya lower limit iliyowekwa (kama vile 0.9 lagging), au wakati mfumo unahitaji uwezo wa miguu zaidi, controller hutoa command ya energizing.

• Energizing: Circuit ya control huchukua vacuum contactor kuwa closed, kuingiza capacitors banki (mara nyingi kupitia reactor wa series) kwenye 10kV busbar kwa pamoja.

• Compensation: Capacitors banki hutumia uwezo wa miguu unaofuata kwenye mfumo, kukata sehemu ya uwezo wa miguu unaofuata, kuboresha power factor, na kusaidia voltage.

• De-energizing: Wakati power factor anapanda juu ya upper limit iliyowekwa (kama vile 0.98 leading, ambayo inaweza kusababisha overcompensation), au wakati voltage ya mfumo inaongezeka, au wakati load reduction inapunguza demand ya uwezo wa miguu, controller hutoa command ya de-energizing, vacuum contactor hufungwa, na capacitors banki hupunguza kazi.

• Discharge: Baada ya capacitors banki kuswitch off, kitu cha kusafisha (discharge coil) hakikisha hukusafisha energy iliyohifadhiwa kwa haraka.

2. Huduma ya Kitu cha Kuzuia Uwezo wa Miguu 10kV

Mafunzo Yake: Kuhakikisha usalama, imani, na ufanisi wa kufanya kazi, na kuongeza muda wa kazi ya vyombo.

2.1 Huduma ya Kila Siku

• Inspection ya Machoni: Angalia casing ya capacitors kwa bulging, leakage ya mafuta, rust, au peeling ya paint; angalia bushings kwa cracks, contamination, au flashover traces; angalia connection points kwa looseness, overheating (infrared thermography), au discoloration.

• Sound ya Kazi: Sikiliza sound ya abnormal vibration au noise kutoka reactors, discharge coils, au capacitors (kama vile "humming" sound ikiwa imeongezeka inaweza kusema kuwa kuna looseness ndani).

• Instrument Indication: Angalia kama voltmeters, ammeters, power factor meters, na reactive power meters wanapiga values normal, na kulingana na values za display ya controller.

• Environmental Check: Angalia ventilation ya ndani, temperature ya mazingira, na humidity kuhakikisha zipo ndani ya limits za allowed; angalia kwa dust accumulation au signs za small animal intrusion; angalia kama fences na labels zipo intact.

• Protection Signals: Angalia kama kuna alarm au trip signals kutoka vyombo vya kuhifadhi.

2.2 Huduma ya Mara Kila Wiku au Mwaka (Maranyingi)

• Cleaning ya Kuswitch Off: Ondoa tofauti na dirt kutoka surfaces za capacitors casings, bushings, insulators, busbars, frames, reactors, na switchgear (using dry, lint-free cloths au special tools, avoiding insulation damage). (Muhimu! Cleaning ya vyombo vya kiwango cha juu lazima ifanyike baada ya kuswitch off, voltage testing, na grounding!)

• Tightening Connections: Angalia na funga vitambaa vyote vya electrical connections (busbar connections, capacitor terminal connections, grounding wires, na kadhalika) kuhakikisha contact nzuri na kupunguza overheating. Fanya kwa torque iliyotengenezwa.

• Capacitor Testing:

• Capacitance Measurement: Tumia capacitance bridge special kuwaangalia total capacitance kwa phase yoyote au branch (iwapo applicable), na kulingana na nameplate values au data za historical. Ikiwa deviation ipita ±5% au ina show significant change (especially decrease), it requires close attention, possibly indicating internal component damage. Capacitance value of a single capacitor should not deviate from the rated value by more than -5% to +10%.

• Insulation Resistance Test: Measure the insulation resistance between poles and between pole and case (using a 2500V megohmmeter), which should meet regulatory requirements (typically, inter-pole insulation resistance should be very high, pole-to-case insulation resistance > 1000MΩ). Must be fully discharged before and after testing!

• Dissipation Factor (tanδ) Measurement: Can be performed if conditions allow, which is more sensitive in reflecting internal capacitor insulation moisture or deterioration. Should not show significant increase compared to factory or previous measurement values.

• Reactor Inspection:

• Check coil appearance for overheating, discoloration, insulation aging, or damage.

• Check if core (if present) fasteners are loose.

• Measure winding DC resistance, which should not show significant difference compared to factory or previous values (considering temperature influence).

• Measure insulation resistance.

• Discharge Device Check:

• Check discharge coil appearance and wiring.

• Verify discharge performance (under safety regulation permission, simulate operation to verify residual voltage drop speed).

• Switching Equipment Maintenance:

• Check vacuum interrupter appearance.

• Check if operating mechanism operates flexibly and reliably; apply appropriate lubricant to lubrication points.

• Measure main circuit contact resistance.

• Perform mechanical characteristic tests (opening/closing time, synchronism, bounce, stroke, etc.).

• Protection Device Calibration: Calibrate settings and perform transmission tests for overcurrent, unbalance, overvoltage, undervoltage, etc., according to regulations to ensure accurate and reliable operation. Check fuse appearance and indicator status.

• Controller Check: Check if display, buttons, and communication are normal; verify sampling accuracy (compare voltage, current, power factor, etc., with standard meter); check if switching logic is correct.

2.3 Huduma Maalum

• Harmonic Environment: Ikiwa mfumo una harmonics serious, weka moja kwa moja monitoring ya temperature rise ya capacitors na reactors (infrared thermography), fanya harmonic tests regular, hakikisha tuning point settings ni reasonable kupunguza resonance. Ongeza filtering devices ikiwa inahitajika.

• Frequent Switching: Weka moja kwa moja inspection ya wear ya contacts ya vacuum contactors/circuit breakers, punguza muda wake wa huduma.

• After Faults: Baada ya protection operation (hasa fuse blowout au unbalance protection operation), sababu lazima ziwaelezwe vizuri, replace components damaged, na kwa kutosha inspection na testing kabla ya kureenergize tena.

2.4 Safety Precautions (Most Important!)

• Strictly enforce the "Two Tickets and Three Systems": Work Ticket, Operation Ticket; Shift Handover System, Patrol Inspection System, Equipment Periodic Testing and Rotation System.

• Power-Off, Voltage Test, Grounding: Before any maintenance work, the power source must be reliably disconnected (including possible back-feeding from PT secondary side), use a qualified voltage tester to confirm absence of voltage, and install grounding wires at both ends of the work location. The capacitor bank must be fully discharged using a dedicated grounding rod and grounded before contact!

• Dedicated Supervisor: Operation and maintenance of high-voltage equipment must have a dedicated supervisor.

• Use Qualified Tools and Protection: Use tools with qualified insulation rating, wear insulating gloves, insulating boots, and other safety protective equipment.

• Residual Voltage Awareness: Even after discharge, use a grounding rod to short-circuit capacitor terminals again before contact.

2.5 Record Keeping and Analysis

• Record data from each inspection, maintenance, and test in detail (capacitance value, insulation resistance, temperature, protection action information, etc.).

• Establish equipment files, perform trend analysis, and promptly identify potential defects.

• Record abnormal conditions and handling processes.

3. Reference for Key Maintenance Intervals

• Daily Inspection: Daily or weekly (depending on importance and operating environment).

• Periodic Cleaning and Inspection (without power-off): Monthly or quarterly.

• Periodic Maintenance (with power-off): Once to twice a year (combined with preventive testing).

• Capacitor Capacitance/Insulation Resistance Measurement: Conducted during power-off maintenance; once within one year of commissioning, then once every 1–2 years.

• Protection Device Calibration: Once a year.

• Switching Equipment Characteristic Test: Combined with power-off maintenance, once every 1–2 years or when operation count reaches a certain value.

4. Notes

• Ambient Temperature: The operating ambient temperature of capacitors must not exceed the specified upper limit (typically -40°C ~ +45°C), avoid direct sunlight.

• Overvoltage: Capacitors can operate long-term at 1.1 times the rated voltage; avoid prolonged overvoltage operation.

• Overcurrent: Capacitors can operate long-term at 1.3 times the rated current (considering harmonic and overvoltage effects).

• Harmonics: Harmonics are one of the main causes of capacitor damage. The system harmonic background must be considered during design, and the reactor ratio configured reasonably. Strengthen harmonic monitoring during operation.