Soluzzjoni ta' Reattur Nanokristallin għal 550kW VFD bl-ispicijiet tal-voltàġġ ta' 5000 V/μs

​1. Sfida: Spike tal-Voltiġġ fuq is-Silġ (du/dt > 5000 V/μs) minn 550kW VFDs f’Mill Rolling tal-Ħadid​

Waqt it-talbija tal-ħadid, il-moturi (speċjalment il-moturi prinċipali għat-talbija tal-ħadid) jgħamlu tifla ta’ impatt mill-balla, eżitjarju rapìd, u tiftix ħafna bejn id-direzzjonijiet. Dawn l-kondizzjonijiet ta’ operazzjoni jagħmlu sfidi kbir għas-sistemi VFD (Variable Frequency Drive), speċjalment f’applikazzjonijiet ta’ potenza kbar (550kW). Il-problema prinċipali hija l-generazzjoni ta’ ratj tat-talbija tal-voltiġġ estremament aħħar (du/dt) fuq is-silġ tal-VFD, manifestati bħal:

• ​Talbija tal-Voltiġġ Estremament Aħħar:​​ Valur tal-spike li jiġu superjuri għal 5000 V/μs. Dan tipikalment jokkulu minn:
• Il-veloċità tal-switching ħafna aħħar tal-dispozitivi IGBT fil-VFD.
• L-effetti tal-parassiti kapacitanza u induttanza tal-kabli tal-motor ħafna twil (speċjalment interagendu mal-tempi tal-ris u tfal tal-PWM waveform tal-VFD).
• Iproblemi ta’ mismatch tal-impedanza bejn karatteristiċi tal-insulazzjoni tal-motor u l-pulsijiet tas-silġ tal-VFD.
• ​Konseguenzi Severi:​​
• ​Dann tal-Insulazzjoni tal-Winding tal-Motor:​​ Id-du/dt estremament aħħar jistgħu ipunċi l-insulazzjoni tal-winding tal-motor, li jilgħaq għal disxarġ parziali, invecchiament insulazzjoni accelerat, u infine falliment jew kollass tal-motor.
• ​Korrenti tal-Bearing u Erosjoni Elettrika:​​ Id-du/dt aħħar, permezz tal-kapacitanza straj, jġeneraw voltàġġ modali, li jilgħaq għal korrenti tal-bearing. Dan jagħmel erosjoni elettrika tal-bearing, zvilupp tal-nies, temperaturi aqra, u skurtan tal-aħħar tal-bearing.
• ​Stress Overvolt tal-Modul IGBT:​​ Is-spike tal-voltiġġ riflessi u sovrapposti jistgħu jgħamru l-IGBT bi voltàġġ istantaneu qrib għal limitu tagħha, jżidu r-riskju ta’ falliment tal-modul ("blowing up").
• ​Interferenza Elettromagnetika (EMI):​​ Is-spike tal-voltiġġ tal-frekwenza aħħar jġeneraw interferenza konduċta u radiata forte, li taflus il-komponenti elettroniku tal-prossimità.
• ​Riduzzjoni tal-Affidabilità tas-Sistema:​​ Ir-riskju ta’ falliment tas-sistema jżid significativament, li jagħmel downtime mhux pianifikat u jaffettwa l-effiċjenza u kontinuità tal-talbija.

​2. Soluzzjoni: FKE Tip Tri-Fażi Reactor tas-Silġ (Nanocrystalline Core)​​

Biex naddrġu l-problema tal-spike tal-voltiġġ aħħar menzionata, nuqqasnu l-installazzjoni ta’ ​FKE Tip Tri-Fażi Reactor​ fuq is-silġ tal-550kW VFD. Din is-soluzzjoni hija disegnata apposutament biex tissoppress id-du/dt aħħar u l-interferenza tal-frekwenza aħħar.

• ​Equipament Kostitutiv:​​ Serje FKE Tri-Fażi Reactor tas-Silġ
• ​Karatteristiċi Prinċipali:​​
• ​Materjal tal-Core:​​ Alleanza Nanocrystalline ta’ performanża aħħar
• Possiedi permeabilità magnetika estremament aħħar u loss core ultra-baħri (speċjalment fid-daqqa tal-frekwenza aħħar ta’ kHz sa MHz).
• Jidher b’mod signifikant aħjar minn materjal tradizzjonali ta’ silġ tal-ħadid jew ferrite fl-isoppressjoni tal-spike tal-voltiġġ tal-frekwenza aħħar u ripple currents ġenerati f’frekwenza switching aħħar (tipikal frekwenza switching tal-IGBT fid-daqqa tal-kHz).
• Forza saturazzjoni magnetika aħħar u kapabbiltà fortissima biex tissostenni overloads transjent.
• ​Teknoloġija Prinċipali 1: Rivestiment ta’ Suppression tal-Eddy Current tal-Frekwenza Aħħar​
• Aplikazzjoni ta’ rivestiment konduttiv speċjali fuq is-silġ nanocrystalline jew is-silġ tal-winding.
• Iddisperżjona effiċjentement il-loss eddy current ultra-frekwenza aħħar (frequenze sal-livell ta’ MHz) indotti mid-du/dt estremament aħħar.
• Jżidu signifikantement ir-riduzzjoni tal-inċreżiment tal-temperatura tal-core fi frekwenzijiet aħħar, jissostennu l-performanża magnetika stabili, u j żidu l-affidabilità ta’ lunga terminu tal-reactor fid-kundizzjonijiet ta’ du/dt aħħar.
• ​Teknoloġija Prinċipali 2: Multi-Layer Sectional Winding Reducing Distributed Capacitance​
• Employs a special multi-layer, sectional winding structure design.
• Divides the equivalent distributed capacitance (Cdw) of a traditional concentrated winding into multiple smaller series-connected capacitive units.
• The overall effective distributed capacitance value is significantly reduced.
• ​Valur Kostitutiv:​​
• Increases the reactor's ​self-resonant frequency​ well above the VFD switching frequency and harmonic frequencies, ensuring it maintains a pure inductive characteristic within the target frequency band.
• Effectively weakens the intensity of the oscillating circuit formed by the VFD's PWM high-frequency pulses and the motor cable's parasitic capacitance, fundamentally suppressing the amplitude and energy of voltage spikes (ringing).
• Reduces the flow of high-frequency oscillating current components through the reactor.
• ​Funkzjonijiet Kostitutivi:​​
• Smooths effiċjentement il-forma tal-voltàġġ, riduċi drasticament id-du/dt fuq is-silġ, jabbassaw is-spike għal livelli siguri.
• Filters out high-frequency harmonic currents, reducing motor harmonic losses and temperature rise.
• Suppresses voltage reflection waves (Wave Reflection).
• Reduces harmonic voltage distortion rate at the line end.
• Reduces the risk of common-mode voltage and bearing currents.
• Reduces conducted and radiated electromagnetic interference (EMI).

​3. Data tal-Performanża (Applikata fis-Scenario tal-550kW Rolling Mill VFD)​​

• ​Suppression tal-Spike tal-Voltàġġ:​​ Id-du/dt fuq is-silġ jiġi mirdud significativament, bl-valur tal-peak jinqassu minn >5000 V/μs għal livelli siguri (pereżempju, <1000 V/μs jew inqas, valuri speċifiċi rikjessu misurazzjoni fuq is-silġ), jisoddisfa l-reqwisiti tal-protezzjoni tal-insulazzjoni tal-motor.
• ​Capability tal-Limitazzjoni tal-Korrent:​​ Jlimita effiċjentement il-korrent inizjali waqt il-start tal-motor jew bidliet soddenti fil-load, proteggjendu l-VFD u l-konnessjonijiet. Il-capability tal-limitazzjoni tal-korrent tista’ tiġi raggiunta sa 30% tal-korrent nominali tal-VFD.
• ​Riduzzjoni tal-Rate tal-Distortjoni tal-Voltàġġ:​​ Filters out high-frequency harmonics. Measured voltage distortion rate (THDv) at the VFD output is reduced by up to 42%, significantly improving power supply quality.
• ​Efett tal-Protezzjoni:​​ Greatly alleviates the reverse recovery surge and overvoltage stress borne by IGBT modules.

​4. Benefiċċji Ekonomiċi​

• ​Significant Extension of Critical Component Lifespan:​​ The most direct and significant economic benefit is seen in:
• ​IGBT Module Lifespan Extension:​​ Effectively reduces the electrical stress (voltage spikes, overcurrent) they endure. Measured data indicates the average service life of IGBT power modules can be prolonged by ​2.3 times. As the core drive equipment of a rolling mill line, the extended lifespan of the VFD's main power components means:
• Reduced procurement quantity and inventory costs of expensive IGBT module spares.
• Significantly decreased unplanned downtime frequency and duration due to power module failures, ensuring continuous production.
• ​Reduced Motor Maintenance Costs:​​
• Effectively protects motor winding insulation, lowering motor insulation failure rates.
• Suppresses bearing currents, reducing bearing electrical erosion damage and replacement frequency.
• Extends the overall service life of motors, delaying major overhauls or replacement cycles.
• ​Improved System Reliability and Production Efficiency:​​
• Reduces the number of VFD or motor failures caused by voltage spikes, enhancing the overall operational reliability (OEE - Overall Equipment Effectiveness) of the rolling line.
• Reduces production losses, scrap risks, and order delays caused by unexpected downtime.
• ​Reduced Maintenance Costs:​​ Minimizes maintenance labor hours and spare parts consumption due to equipment damage.
• ​Improved Power Factor (Indirectly):​​ Improved waveform contributes to optimizing the system power factor (although primarily handled by input reactors or active compensation, output reactor waveform improvement also provides some benefit).