Vyanzo Vya Mtaani ya Kurekebisha Voliti vya Tawi katika Mipango ya Umeme

1 Uchunguzi wa Kwanza​

​Vingineko vya Mipango ya Umeme katika Mitandao ya Sasa:​​

• Mikabilo mrefu yanayosababisha upungufu wa voltage;
• Unganishaji wa nyuzi za nishati zinazowezekana kutoka sehemu mbalimbali (DER) unavyosababisha mzunguko wa nguvu kwa pande zote;
• Mabadiliko ya mizigo yanayosababisha mabadiliko mara kwa mara ya voltage.

​Misemo ya Teknolojia za Step Voltage Regulators (SVRs):​​

• Inatumia teknolojia ya kupata tap kwa kubadilisha uwiano wa windings ya transformer, kuwasilisha mzunguko wa ±10% wa voltage (kawaida katika hatua 32, 0.625% kwa kila hatua);
• Vipengele muhimu vinavyopatikana ni uwezo wa kubadilisha mapema na muda mzima pamoja na misemo mingine mengi, kunaweza kutoa msaada wa voltage wenye ubunifu kwa mitandao ya umeme.

​Mwenendo wa Maendeleo ya Teknolojia:​​

• Imetoka kutoka kwa switches ya tap ya mifano msingi hadi kwa mikoa imara yenye elektroniki ya nguvu, algorithms za utaratibu wa kutosha, na modules za mawasiliano ya akili;
• Mfano wa kirefu: ABB SPAU341C unayojumuisha uwezo wa Line Drop Compensation (LDC), unayotumia tabia za impedance ya mstari kwa mafanikio ya mazingira ya msaada wa voltage;
• Matumizi ya relays zinazodhibitiwa na magnetic na TRIACs inapunguza hasara na ukubwa wa vifaa, kukusanya ufanisi na gharama.

​2 Msingi wa Teknolojia & Muundo​

​Mechanismo ya Msimamizi wa Voltage:​​

• Hutimiza mswala wa voltage kwa kubadilisha uwiano wa windings ya transformer, kujitumia teknolojia ya On-Load Tap Changers (OLTCs).

​Mchakato wa Utaratibu wa Feedback wa Kutofautiana:​​

1. Transformers za voltage huendesha amri za system ya voltage;
2. Amri za tofautiana zinajengwa kwa kulingana na thamani zilizopatikana na thamani za reference;
3. Kitengo cha mawasiliano huchagua jinsi ya kubadilisha tap (boost/buck) na ukubwa wa hatua kulingana na amri za tofautiana.

​Parameta Zenye Ubunifu za SVRs Za Sasa:​​

• Kwa mfano wa SPAU341C: Inasaidia hatua za mabadiliko ya voltage za 0.625%, kusaidia mabadiliko ya precise voltage katika hatua 32 kwenye mzunguko wa ±10%.

​2.1 Vifaa Vikuu​

• ​On-Load Tap Changer (OLTC):​​ Mtendaji mkuu wa regulator, unaotumia vacuum interrupters kurekebisha arcing. Resistors za transition huchukua current wakati wa kubadilisha, kusaidia kuzuia utambuzi wa mizigo. Mifano ya sasa yanasaidia teknolojia ya dual-resistor transition, kupunguza muda wa kubadilisha kwenye sekunde 40-60.
• ​Module ya Mawasiliano:​​ Imejenga juu ya microprocessors (ARM/DSP), imejumuisha misemo mingi. ABB SPAU341C anatumia muundo wa modular, unahusu modules za connection, I/O, na module ya automatic voltage regulation, isaidia mawasiliano ya muda mzima kwa ajili ya diagnostics ya hardware na software.
• ​Unit ya Measurement na Protection:​​ Transformers za Voltage/Current (kama vile PT1, PT2, TA1) huendesha amri za system. Vituo vimejumuisha uwezo wa overcurrent na undervoltage blocking. Wakiangalia short circuit au dip ya voltage, operations za tap-changing zinachukuliwa haraka kusaidia kuzuia sarafu.
• ​Mawasiliano na Operation Interface:​​ Husaidia Ethernet, GPRS, na protocols mingi za mawasiliano kwa ajili ya mawasiliano ya mbali na settings. Module ya display hutumia kwa ajili ya mawasiliano ya mahali, inaruhusu kutambua parameta kama vile setpoints na measured values.

​2.2 Matukio Muhimu​

​3 Solutions za Matumizi katika Design ya Distribution System​

​3.1 Scenarios za Matumizi Zinazofanana​

• ​Mikabilo Refu:​​ Application ya classic SVR. Katika mitandao ya umeme wa deserts, mstari wa 10kV hupanda kwa umbali zaidi ya 15km, kusababisha deviation ya voltage kwenye end ya feeder. Kuboresha SVRs mid-line au kwenye end ya feeder kunaweza kusaidia kushughulikia voltage drops. Practices za engineering zinatoa kuwa SVR moja inaweza kuongeza radius ya feeder kwa asilimia 30%, kunongeza compliance rate ya voltage kwenye end ya feeder kutoka chini ya 70% hadi zaidi ya 98%, kunyonga gharama za upgrade za mstari.
• ​Mitandao ya Urban High-Density:​​ Hupata changamoto za mabadiliko ya mizigo na voltage mismatch. SVRs zinapatikana kwenye outlets za substation au ring main unit (RMU) nodes. Katika project ya commercial district ya city, kuweka SVRs kwenye nodes muhimu nne iliyopunguza fluctuation ya voltage kwenye peak-hour kutoka ±8% hadi ±2%, pamoja na kusababisha losses za mstari kwa asilimia 12% kwa reactive power optimization.
• ​Maeneo yenye Penetration ya DER ya Juu:​​ Yanahitaji kusimamia changamoto za bidirectional power flow. Wakati penetration ya PV inzuka zaidi ya 30%, mitandao ya umeme ya msingi mara nyingi hupata violations za voltage. SVRs hupata control logic kwa mode ya reverse power, kusababisha reduction ya voltage kwenye muda wa generation surplus. Project ya PV demonstration iliyo tumia coordinated control kati ya SVRs na PV inverters iliongeza uwezo wa hosting wa PV kwenye eneo la kiwango cha 25% na kusababisha kusababisha rates za curtailment kwa asilimia 18%.

​3.2 Usimamizi wa Strategy wa Control​

• ​Voltage-Var Optimization (VVO):​​ Hucooperate SVRs na shunt capacitor banks kusababisha losses za system.
• ​Coordinated Control ya Multi-Stage:​​ Kwa installations za multiple SVRs katika mitandao magumu, yanapaswa kusababisha conflicts ya control. Time Delay Coordination Method ni suluhisho sahihi—kuisaidia delay ya upstream SVR (kawaida katika sekunde 30-60) kusababisha mara mbili delay ya downstream SVR. Wakati voltage violation inapatikana, downstream SVR huchukua hatua kwanza. Ikiwa tatizo linakuwa kwa muda zaidi ya window lake, upstream SVR huchukua hatua. Tarehe hii inaweza kusababisha tap operations zenye gharama (kwa asilimia 40%) wakati unaweza kusaidia stability ya voltage.
• ​Strategies za Adaptive Control:​​ SVRs ya sasa (kama vile SPAU341C) hujumuisha self-learning algorithms kusababisha needs za adjustment ya voltage kulingana na historical load profiles. System hutoa tap positions kwa muda wa similar daily load patterns (kama vile morning peaks), kusababisha response times za voltage adjustment kutoka dakika hadi sekunde. Tarehe hii inaweza kusaidia fluctuations za PV output au scenarios za electric vehicle (EV) charging.

​3.3 Matrix ya Scenario Selection​

​4 Performance Optimization & Innovative Technologies​

​Loss Reduction Technology:​​

Hybrid switching technology ni innovation muhimu ya kusababisha losses za SVR. Tap changers wa msingi wa mechanical wanapata resistance ya contact katika mΩ na arcing losses zinazozidi. Suluhisho la sasa linatumia muundo wa Magnetic Latching Relays na Back-to-Back Thyristors:

• ​Steady-State Conduction:​​ Handled by the Magnetic Latching Relay (contact resistance <1mΩ)
• ​Transition Moment:​​ The Back-to-Back Thyristor provides a current path (trigger time <2μs)
• ​Post-Switch Steady-State:​​ Mechanical contacts close again, semiconductor devices turn off.
  This design reduces switching losses by 80%, shrinks equipment volume by 40%, achieves arc-less switching, and extends equipment lifespan. Actual operating data shows hybrid-switch SVRs incur 55% lower annual maintenance costs compared to traditional models.

​Innovation ya Topology​ pia inasaidia sana. Cascaded Voltage Regulator anatumia muundo wa hybrid na series transformer na shunt capacitor, anaweza kutoa tarehe tatu za matumizi:

1. ​Equivalent Series Compensation Mode:​​ Targets voltage boost at the end of long lines.
2. ​Voltage-Var Adjustment Mode:​​ Coordinates voltage and reactive power optimization.
3. ​Pure Voltage Regulation Mode:​​ Enables rapid response to voltage sags.
   This design reduces system losses by 15-20% at the same capacity while improving fault ride-through capability.

​5 Application Cases & Practical Experience​

​5.1 Voltage Boost on Rural Long-Distance Feeder​

• ​Project Background:​​ A 28km 10kV feeder in a mountainous area supplied dispersed loads. End voltage during peak hours dropped to 8.7kV (below standard lower limit: 9.7kV), failing to meet power requirements for irrigation pumps. Traditional solutions required a new substation at over ¥8 million cost.
• ​Solution:​​ Two ABB SPAU341C regulators deployed in series at the 12km and 22km points, utilizing a Master-Slave coordination strategy.
• Device Configuration: Each SVR: 800kVA, ±15% range, LDC-enabled.
• Control Strategy: Master station (22km) delay: 60 seconds; Slave station (12km) delay: 30 seconds.
• Compensation Parameters: Virtual R = 0.32Ω, X = 0.45Ω (simulating line impedance).
• ​Results:​​
• End voltage stabilized at 9.8-10.2kV; compliance rate rose from 61% to 99.6%.
• Insufficient starting torque issue for pumps during irrigation season peak load completely eliminated.
• Total investment: ¥1.8 million (77.5% cost reduction vs. new substation).
• Annual energy loss reduction: ~150 MWh, corresponding to energy cost savings of ~¥120,000.

​5.2 Power Quality Improvement in Urban High-Density Area​

• ​Project Background:​​ Within an urban RMU's supply area, clustered commercial complexes and EV charging stations caused voltage fluctuations reaching ±8%. Transformer loading reached 130% during peak hours.
• ​Solution:​​ Deployment of an SVR + Dynamic Var Compensation (SVG) system at the RMU inlet.
• Device Selection: SPAU341C Regulator (1250kVA) with ±200kVar SVG.
• Control Architecture: VVO coordination controller performing joint optimization every 5 minutes.
• Prediction Algorithm: Deep learning-based load forecasting (accuracy >92%).
• ​Results:​​
• Voltage fluctuation controlled within ±2% (compliant with IEEE 519).
• Transformer loading reduced to 85%, freeing up 30% capacity.
• Comprehensive line losses reduced from 7.8% to 6.2%, yielding annual savings ~¥80,000.
• Charging pile failure rate reduced by 40%; user complaints decreased by 90%.