Vipi ni Aina za Reactors? Majukumu Muhimua katika Mipango ya Nishati

Reactor (Inductor): Maana na Aina

Reactor, ambalo linavyojulikana kama inductor, huchambua mageto katika maeneo yake mazingira wakati kila chini ya umeme hutoka kwenye conductor. Kwa hiyo, chochote conductor kinachotumia umeme huwa na inductance. Lakini, inductance ya conductor wa mwisho ni ndogo na hutoa mageto machache. Reactors halisi hazijengewi kwa kurekebisha conductor kwenye mfumo wa solenoid, ambao unatafsiriwa kama air-core reactor. Ili zaidi kupunguza inductance, core wa ferromagnetic unawekezwa kwenye solenoid, kuunda iron-core reactor.

1. Shunt Reactor
Umbizo wa shunt reactors lilikuwa linatumika kwa ajili ya uji wa full-load wa generators. Iron-core shunt reactors hutoa nguvu za mageto zenye kuvunjika kati ya sehemu za core, kutokufanya sauti zinazopanda mara 10 dB zaidi kuliko transformers wa ubora sawa. Shunt reactors hutoa alternating current (AC) na hutumiwa kuboresha system capacitive reactance. Mara nyingi yanajunganishwa kwa series na thyristors ili kuboleza utaratibu wa reactive current.

2. Series Reactor
Series reactors hutoa AC current na hujunganishwa kwa series na power capacitors ili kunda circuit wa series resonance kwa harmonics za steady-state (mfano, 5th, 7th, 11th, 13th harmonics). Series reactors typical wanayo thamani za impedance 5–6% na huathirika kama aina za high-inductance.

3. Tuning Reactor
Tuning reactors hutoa AC na hujunganishwa kwa series na capacitors ili kunda series resonance kwenye harmonic frequency iliyochaguliwa (n), kwa hivyo kutoa component hiyo ya harmonic. Taratibu za tuning zinazofanikiwa ni n = 5, 7, 11, 13, na 19.

4. Output Reactor
Output reactor unaelekea current ya charging ya capacitive katika motor cables na kunyonga rate ya voltage rise kwenye motor windings kwenye 540 V/μs. Ni lazima kwa wakati mwingine wakati length ya cable kati ya variable frequency drive (VFD) (4–90 kW) na motor unapita 50 meters. Pia hunyongeza VFD output voltage (kupunguza steepness ya switching edge), kuboresha disturbances na stress kwenye inverter components kama vile IGBTs.

Maelezo kwa Output Reactors:
Ili kudondosha umbali kati ya VFD na motor, tumia cables za ukubwa zaidi na insulation imara, bila kusoma types.

Vipengele vya Output Reactors:

• Vyafanikiwa kwa reactive power compensation na harmonic mitigation;

• Kutetezi distributed capacitance katika cables refu na kuzuia output harmonic currents;

• Kutetezi vizuri VFDs, kuboresha power factor, kukuzuia grid-side interference, na kupunguza harmonic pollution kutoka rectifier units hadi grid.

5. Input Reactor
Input reactor unaelekea voltage drops upande wa grid wakati wa converter commutation, kunyonga harmonics, na kugeuka parallel converter groups. Pia unaweka hatari current surges zinazotokana na grid voltage transients au switching operations. Wakati ratio ya grid short-circuit capacity kwa VFD capacity unapita 33:1, relative voltage drop ya input reactor lazima iwe 2% kwa single-quadrant operation na 4% kwa four-quadrant operation. Reactor anaweza kufanya kazi wakati grid short-circuit voltage inapita 6%. Kwa 12-pulse rectifier unit, line-side input reactor unaohitaji voltage drop asilimia 2 au zaidi ni lazima. Input reactors zinatumika sana katika systems za industrial na factory automation control. Zinainstall kati ya power grid na VFDs au speed regulators, kunyonga surge voltages na currents zinazotokana na devices hizo, kuboresha sana higher-order na distorted harmonics katika system.

Vipengele vya Input Reactors:

• Vyafanikiwa kwa reactive power compensation na harmonic filtering;

• Kunyonga current surges zinazotokana na grid voltage transients na switching overvoltages; kunyonga harmonics kuboresha distortion ya voltage waveform;

• Kunyonga spikes za voltage na notches za commutation kwenye bridge circuits.

6. Current-Limiting Reactor
Current-limiting reactors mara nyingi zinatumika katika distribution circuits. Zinajunganishwa kwa series na feeder lines zinazotoka kutoka kwa busbar moja ili kuzingatia current ya short-circuit na kudumisha stability ya bus voltage wakati wa faults, kunyonga voltage drops zisizotakikana.

7. Arc Suppression Coil (Petersen Coil)
Yaliyotumika sana katika systems za resonant grounded kwenye 10kV–63kV, arc suppression coils zinazotumika zaidi ni dry-type cast resin design kutokana na mwenendo wa oil-free substations, hasa kwa systems chini ya 35kV.

8. Damping Reactor (mara nyingi synonymous na Series Reactor)
Zinajunganishwa kwa series na capacitor banks au compact capacitors, damping reactors zinaweka hatari inrush current wakati wa capacitor switching—vyo vya kazi kama current-limiting reactors. Filter Reactor: Wakati zinajunganishwa kwa series na filter capacitors, zinunda resonant filter circuits, mara nyingi zinatumika kwa 3rd hadi 17th harmonic filtering au high-pass filtering ya order zisizotakikana. HVDC converter stations, phase-controlled static VAR compensators, large rectifiers, electrified railways, na high-power thyristor-based electronic circuits zote ni sources za harmonic current ambazo zinapaswa kinyang'anywa ili kutokunyonga harmonic injection kwenye grid. Power utilities ina regulations maalum kuhusu levels za harmonics katika power systems.

9. Smoothing Reactor (DC Link Reactor)
Smoothing reactors zinatumika katika DC circuits baada ya rectification. Tangu rectifier circuits zinatoa number finito ya pulses, output DC voltage ina ripple, ambayo mara nyingi ni dharura na lazima ikinyang'anywe na smoothing reactor. HVDC converter stations zinapatikana na smoothing reactors ili kufanya output DC kuwa karibu na ideal. Smoothing reactors pia zinahitajika katika thyristor-controlled DC drives. Katika rectifier circuits, hasa medium-frequency power supplies, majukumu yao muhimu ni:

• Kunyonga short-circuit current (wakati wa inverter thyristor commutation, simultaneous conduction ni sawa na direct short-circuit kwenye output ya rectifier bridge); bila reactor, hii ingeweza kutoa direct short;

• Kunyonga the impact of medium-frequency components kwenye utility power grid;

• Effect ya filtering—rectified current ina components za AC; high-frequency AC inapigwa hatari na inductance kubwa—kuthibitisha continuous output current waveform. Discontinuous current (na zero-current intervals) ingeweza kutoa inverter bridge to stop, kutokana na open-circuit condition kwenye rectifier bridge;

• Katika parallel inverter circuits, reactive power inaexchangwa kwenye input; kwa hivyo, energy storage elements—reactors—zinahitajika katika input circuit.

Maoni Muhimu

Reactors katika power grids zinatumika kutoa capacitive reactive power inayotokea kutokana na cable lines. Kwa kutengeneza idadi ya shunt reactors, system operating voltage inaweza kurekebishwa. Ultra-high voltage (UHV) shunt reactors zinatenda majukumu mengi yaliyohusiana na reactive power management katika power systems, ikiwa ni:

• Kunyonga the capacitive effect kwenye transmission lines yenye mtihani mdogo au hakuna mtihani, kupunguza power-frequency transient overvoltages;

• Kuboresha voltage distribution kwenye long transmission lines;

• Kubalanshi reactive power locally under light load conditions, kunyonga unreasonable reactive power flow na kupunguza line power losses;

• Kupunguza steady-state power-frequency voltage kwenye high-voltage busbars wakati generators kubwa kuanza kusynchronize kwenye grid, kuboresha synchronization ya generator;

• Kunyonga self-excitation resonance ambayo inaweza kutokea wakati generators zinajunganishwa kwenye long transmission lines;

• Wakati neutral ya reactor imegrounded kwa small reactor, small reactor inaweza kutoa inter-phase na phase-to-ground capacitance, kubadilisha haraka extinction ya residual currents na kuboleza single-pole auto-reclosing.

Reactors zinajunganishwa kwa series au parallel. Series reactors zinatumika kwa ajili ya kunyonga current, na shunt reactors zinatumika kwa ajili ya reactive power compensation.

• Shunt Reactor: Katika ultra-high voltage long-distance transmission systems, zinajunganishwa kwenye tertiary winding ya transformers kuboresha capacitive charging current ya transmission lines, kunyonga voltage rise na switching overvoltages, na kuhakikisha mazingira ya kazi ya system.

• Series Reactor: Zinapatikana katika capacitor circuits, zinatumika wakati capacitor bank inatumika.