Mga Inobatibong Solusyon sa mga Step Voltage Regulator sa mga Sistema sa Distribusyon ng Kapangyarihan

1 Executive Summary​

​Mga Hamon sa Paghahandle ng Voltage sa Modernong Mga Distribution Network:​​

• Mga long-distance feeders na nagdudulot ng pagbaba ng voltage;
• Integrasyon ng distributed energy resource (DER) na nagdudulot ng bidirectional power flow;
• Pagbabago ng load na nagdudulot ng madalas na pagbabago ng voltage.

​Teknikal na mga Katangian ng Step Voltage Regulators (SVRs):​​

• Ginagamit ang tap-changing technology para baguhin ang ratio ng winding turns ng transformer, nakakamit ang ±10% voltage adjustment range (karaniwang 32 steps, 0.625% bawat step);
• Ang pangunahing mga benepisyo ay nasa real-time dynamic adjustment capabilities kasama ang maraming control strategies, nagbibigay ng flexible voltage support para sa distribution grid.

​Trends sa Teknolohiya ng Pag-evolve:​​

• Nag-evolve mula sa basic mechanical tap switches hanggang sa integrated systems na may power electronics, adaptive control algorithms, at intelligent communication modules;
• Halimbawa: Ang ABB SPAU341C ay may Line Drop Compensation (LDC) functionality, sumasalamin sa line impedance characteristics para sa precise voltage control sa remote load points;
• Ang paggamit ng magnetically held relays at TRIACs ay nagbabawas ng equipment losses at footprint, nagpapataas ng deployment flexibility at cost-effectiveness.

​2 Teknikal na Prinsipyo & Struktura​

​Pangunahing Mechanism ng Voltage Regulation:​​

• Nakakamit ang voltage regulation sa pamamagitan ng pagbabago ng ratio ng winding turns ng transformer, depende sa tap-changing technology ng On-Load Tap Changers (OLTCs).

​Closed-Loop Feedback Control Process:​​

1. Ang voltage transformers ay patuloy na kumukuha ng system voltage signals;
2. Ang error signals ay ginagawa sa pamamagitan ng paghahambing ng acquired values sa set reference values;
3. Ang control unit ay nagdedesisyon kung anong direction ng tap change (boost/buck) at step size batay sa error signal.

​Pangunahing Teknikal na Mga Parameter ng Modern SVRs:​​

• Tinutukoy ang SPAU341C bilang halimbawa: Suportado ang fine voltage adjustment steps ng 0.625%, nagbibigay ng 32-step precise voltage regulation sa loob ng ±10% range.

​2.1 Pangunahing Komponente​

• ​On-Load Tap Changer (OLTC):​​ Ang core actuator ng regulator, gumagamit ng vacuum interrupters upang mabawasan ang arcing. Ang transition resistors ay nag-aasikaso ng current continuity sa panahon ng switching, nagpaprevent ng load supply interruption. Ang modern designs ay gumagamit ng dual-resistor transition technology, nagbabawas ng switching times sa 40-60 milliseconds.
• ​Control Module:​​ Itinayo sa high-performance microprocessors (ARM/DSP), nag-integrate ng multiple control strategies. Ang ABB SPAU341C ay gumagamit ng modular architecture, binubuo ng connection modules, I/O modules, at automatic voltage regulation module, suportado ang continuous self-monitoring para sa real-time hardware at software diagnostics.
• ​Measurement and Protection Unit:​​ Voltage/Current Transformers (e.g., PT1, PT2, TA1) patuloy na kumukuha ng system parameters. Ang units ay may three-phase overcurrent at undervoltage blocking functions. Kapag natuklasan ang short circuit o severe voltage dip, ang tap-changing operations ay agad na inaabutan ng block para mabawasan ang damage sa equipment.
• ​Communication and Operation Interface:​​ Suportado ang Ethernet, GPRS, at iba pang communication protocols para sa remote monitoring at parameter settings. Ang display module ay nagbibigay ng local operating interface, ipinapakita ang key parameters tulad ng setpoints at measured values sa real-time.

​2.2 Pangunahing Operational Characteristics​

​3 Application Solutions sa Design ng Distribution System​

​3.1 Typical Application Scenarios​

• ​Mga Long Radial Feeders:​​ Isang classic SVR application. Sa rural distribution networks, ang 10kV lines madalas na lumalampas sa 15km, nagdudulot ng malaking voltage deviation sa feeder end. Ang pag-deploy ng SVRs mid-line o sa feeder end ay epektibong nagko-compensate sa voltage drops. Ang engineering practices ay nagpapakita na ang iisang SVR ay maaaring palawakin ang feeder radius ng 30%, nagpapataas ng voltage compliance rate sa feeder end mula sa below 70% hanggang sa higit sa 98%, nagpapabawas ng line upgrade costs.
• ​High-Density Urban Distribution Networks:​​ Nagtatapat sa hamon ng load fluctuation at voltage mismatch. Ang SVRs ay karaniwang inilalapat sa substation outlets o ring main unit (RMU) nodes. Sa isang city commercial district retrofit project, ang pag-install ng SVRs sa 4 key nodes ay nagresulta sa pagbawas ng peak-hour voltage fluctuation mula ±8% hanggang ±2%, samantalang nagpapabawas din ng line losses ng 12% sa pamamagitan ng reactive power optimization.
• ​High DER Penetration Areas:​​ Nangangailangan ng pag-manage ng bidirectional power flow challenges. Kapag ang PV penetration ay lumampas sa 30%, ang traditional distribution networks madalas na nag-eexperience ng voltage violations. Ang SVRs ay awtomatikong nag-adjust ng control logic sa pamamagitan ng reverse power mode, aktibong nagpapababa ng voltage sa panahon ng generation surplus. Ang isang PV demonstration project na gumagamit ng coordinated control between SVRs at PV inverters ay nag-increase ng local PV hosting capacity ng 25% at nagpapababa ng curtailment rates ng 18%.

​3.2 Optimization ng Control Strategy​

• ​Voltage-Var Optimization (VVO):​​ Coordinates SVRs with shunt capacitor banks to minimize system losses.
• ​Multi-Stage Coordinated Control:​​ Para sa cascade installations ng multiple SVRs sa complex networks, kailangang iwasan ang control conflicts. Ang Time Delay Coordination Method ay ang pinakapraktikal na solusyon—set the upstream SVR's delay (typically 30-60 seconds) to at least double the downstream SVR's delay. Upon detecting a voltage violation, the downstream SVR acts first. If the issue persists beyond its delay window, the upstream SVR then intervenes. This approach significantly reduces unnecessary tap operations (by up to 40%) while maintaining voltage stability.
• ​Adaptive Control Strategies:​​ Ang modern SVRs (e.g., SPAU341C) ay naglalaman ng self-learning algorithms para i-predict ang voltage adjustment needs batay sa historical load profiles. Ang sistema ay awtomatikong pre-adjusts tap positions during periods of similar daily load patterns (e.g., morning peaks), reducing voltage adjustment response times from minutes to seconds. This strategy is particularly suitable for PV output fluctuations or scenarios with concentrated electric vehicle (EV) charging.

​3.3 Scenario Selection Matrix​

​4 Performance Optimization & Innovative Technologies​

​Loss Reduction Technology:​​

Hybrid switching technology is a core innovation for minimizing SVR losses. Traditional mechanical tap changers suffer from contact resistance in the tens of mΩ and significant arcing losses. The modern solution employs a hybrid structure of Magnetic Latching Relays and 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.

​Topology Innovation​ also contributes significantly. The Cascaded Voltage Regulator adopts a hybrid structure with a series transformer and shunt capacitor, offering three optional operating modes:

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%.