Têkniyên Nîvînî yên Kurrêtên Dîrek Sîtîk û DC Da Çend Bîhêr

1 Wanên Tîkne

1.1 Stabilîyetiye Cihazan Paralel
Di vebijarkên praktîkî de, hêza daxistinê yên cihazên elektronîkê yên nîrgirî ye. Ji bo pêvajoyên daxistina meh, her du cihaz paralel bûn dihewînin. Lekin, guhertinên parametre û taybetmendiyên cihazan—wisa dişûniyên nirxên on-resistance û threshold voltage—dibe ku daxistina herêmî ne di rêjeya paralel de beseheve. Di dema transîyonê de, induktansiya û kapasitansîya parazîtî da dest pê ceriya daxistina herêmî dibin da ku dikare beseheve, ya ku divê xweşkirina daxistine herêmî biguheze. Eger ê veqetand bike, ev bisehevîsa daxistine herêmî dikare ku hêsan cihazan bi daxistina zêdetir bike û lêzêde bikin, ji bo ku mîndina jiyanê ya circuit breaker-a solid-state-ê biçine.

1.2 Dera Bikeşkirina Kesha
Di sisteman DC de, taybetmendiyên daxistina kesha wek bi AC-sistemên din diguherîn, ku navberên zero-crossing nayê ku alîkarên bikeşkirina û keta kesha biguheze. Ev têne ku circuit breaker-an solid-state an jî algoritman bikeşkirina li ser mikrosecond bikin da ku bi rastî kesha biguheze û bi çabdarî tepike biguheze. Metodên tradîsyonî bikeşkirina kesha di dema bikarhênerên daxistina kesha DC-ê çabdar ê derbikin, ku nayê bekevin da ku dest pê barnameya parzûna çabdar bide.

1.3 Pirsgirtina Herdem û Hacim
Ji bo piştgiriya vebijarkên nîrgirî yên modern da ku hewceyên density-ê yên nîrgirî yê bibin, dizaynê ya circuit breaker-an solid-state an jî dest pê ku nîrgirî zêdetir bide di hewnê bicîh de. Lekin, density-ê ya nîrgirî zêdetir bisekin da ku çendina zêde ya çalakê di cihazan elektronîkê de biguheze. Herdem û hêdanîya çalakê nayê bekevin da ku tevahîya zêde bike, ku têne ku performansa cihazan bike û dikare ku trigger-î thermal runaway û lêzêde cihaza biguheze. Teknikên herdem û hêdanîya tradîsyonî li ser circuit breaker-an solid-state an jî li vir nayê bekevin. Ewra hêdanîya liquid dikare ku efektiviteya herdem û hêdanîya biguheze, lê hêrekî ew hewn û maliyê cihaza zêdetir bike. Ji ber vê yekê, ji bo pirsgirtina efektiv herdem û hêdanîya û kontrola hacmiya rastîn—dest pê optimalizasyonê hevdarmîn—ji wan wan dikare ku bibe ku pirsengelî ya sereke ya dizaynê ya circuit breaker-an solid-state an jî bibe.

2 Li Ser Bajarên Tirîjî

2.1 Tirîjî Teqnolojîya Cihazan Bandgap-i Gazî
(1) SiC MOSFET Selection and Packaging
Dilindixan cihazan bandgap-i gazî, SiC MOSFET-an bi low-conduction-loss taybetmendîyên serpildan hene. Ji bo piştguherniya performansa watan di bikarhênerên multi-device parallel de, layout-i Direct Bonded Copper (DBC) simetrî hatine benusîn. Ev layout çendina parasitic inductance reke, ku têne ku herî şîr e ji bo amadekirina switching characteristics-ê. Di switching de, paşê ya turn-off, interaksiyon û têne di antara parasitic inductance û capacitance-ê de gate voltage oscillation biguheze. Testan eksperîmentî hatine rastîn da ku bi layout-i DBC simetrî, gate voltage oscillation li ser 5% dikare kontrol bike. Ev nîha performansa dinamîkî di rêjeya parallel operation de beseheve û riska damage-ê ya cihaz ji oscillation-ê ya voltage reke.

(2) Kontrola Herêmî Dynamic Current Sharing
Ji bo pirsengelîya herêmî current sharing-ê, strategîya kontrol ên bi kombinasyon ît bus-i current-sharing û regulasyon adaptive PI hatine serok kirin. Bus-i current-sharing, bi design struktural unik, rota herêmî current distribution fîzikî yên her parallel branch-ê jêrdebike. Bi vê binyamin, algoritma adaptive PI regulation dinamîkî signalan drive-ê yên her cihaz bi monitoring-ê ya real-time-î ya branch currents-ê re adjust dake, control-i current sharing-ê yên zêde rastîn biseheve.

2.2 Teqnolojîya Bikeşkirina û Interruption Fast
(1) Bikeşkirina Kesha Li Ser Gate Voltage
Analiza taybetmendiyên short-circuit-ê ya SiC MOSFET hatine rastîn da ku di dema kesha short-circuit de, drain-source voltage (VDS) bi çabdarîya 900V beseheve û gate voltage bi slope-i 10 V/ns reke. Bi serîlîna taybetmendiyên în, comparator-i dual-threshold ji bo bikeşkirina çabdar hatine disenî. Divê bi iki threshold current: Ith1 = 500 A û Ith2 = 1.2 kA. Jeger daxistina detektand bike Ith1, warning-i birînî hatine trigere; Ith2 reke kesha short-circuit hatine rastîn. Circuit-i detektand û algoritma signal processing-ê hatine disenî da ku delay-i detektand tikî 0.8 μs bike. Ev metoda bikarhênerên electrical characteristics-ê ya inherent ya SiC MOSFET-ê reke, accuracy-i bikeşkirina kesha zêde bike.

(2) Strategîya Interruption Multi-Objective Optimized
Ji bo bikeşkirina high-performance-ê di circuit breaker-an solid-state de, interruption time (Δt), energy absorption (EMOV), û inrush current (Ipeak) hatine set kirin da ku objective functions beseheve, bi algoritma multi-objective particle swarm optimization (MOPSO) optimized bikin. Time-i interruption-i keva hatine piştgirîya cihazan sistemê; energy absorption selection û lifespan-ê ya protective components yên wek MOVs-ê biguheze; inrush current-i keva electrical stress-ê bize, operasyona normal cihazan reke.

Bi multiple iterations of MOPSO optimization, parameters-i optimal hatine rastîn: current-limiting inductor LB = 15 μH û MOV voltage-limiting coefficient γ = 1.8. Bi parameters-i optimized, interruption time hatine reduce kirin da 73.5 μs besehe û maximum current hatine limit kirin da 526 A besehe. Ji bo vividly show the optimization effect, TOPSIS decision-making method results before and after optimization compare. Comparison shows significant improvements in key indicators such as interruption time, energy absorption, and inrush current, greatly enhancing overall performance and better meeting practical engineering requirements for fast and reliable interruption by solid-state circuit breakers.

2.3 Design-i Mechanical Structure High-Reliability
(1) Permanent Magnet Isolator Switch
Ji bo amadekirina reliability û stability-ê ya circuit breaker-an solid-state, permanent magnet isolator switch bi mechanism-i bistable permanent magnet hatine disenî. Di vê struktur de, holding force-i closing û opening yê jêrdebike di permanent magnets de, coil energized tikî momentan di dema switching operations de. Ev power consumption reduce dake bi 90% li vir electromagnetic isolator switches-ê. Adams dynamic simulation analysis shows that the mechanical life of this permanent magnet isolator switch exceeds 1 million operations, with a contact separation speed of 3 m/s. The high contact separation speed ensures rapid circuit disconnection upon fault occurrence, reducing the likelihood of arc generation and enhancing the switch's interruption capability. The long mechanical life ensures stable performance over extended use, reducing maintenance and replacement frequency, thus providing strong support for the efficient operation of the solid-state circuit breaker.

(2) Çareserîya Thermal Management
Ji bo pirsengelîya herdem û hêdanîya li ser designs-ê yên high-power-density, solution-i cooling hybrid bi combination evaporative cooling û forced air cooling hatine propozîkirin. Evaporative cooling principle-i liquid evaporation absorbing heat reke, enabling efficient heat transfer within compact spaces. Forced air cooling further enhances heat dissipation through fan-driven forced convection. This hybrid cooling method stabilizes the module's hotspot temperature below 75°C, with a temperature rise rate of less than 5°C/min, meeting standard requirements.III. Experimental Verification

3 Experimental Verification

3.1 Prototype Parameters
To verify the effectiveness of the key technologies and design schemes, a prototype of a low-voltage DC solid-state circuit breaker was developed, with the main parameters as follows:

3.2 Type Test Results

Comprehensive type tests were conducted on the prototype to evaluate whether its performance meets the requirements for practical applications:

(1) Short-Circuit Interruption Test
Short-circuit faults are among the most severe fault types in power systems, and the enormous instantaneous current they generate poses a significant threat to equipment operation. To simulate this extreme condition, a 23 kA short-circuit current test environment was established—posing a rigorous challenge for the solid-state circuit breaker. At the start of the test, the prototype rapidly activated, and its built-in fast fault detection and interruption technology began to function. This technology, through high-precision current monitoring and a rapid response mechanism, detected the abnormal current within an extremely short time and immediately triggered the interruption process.

During interruption, test personnel closely observed the breaker's performance, and no arc re-ignition occurred throughout the process. This result not only demonstrates the high efficiency of the fast fault detection and interruption technology but also highlights the solid-state circuit breaker's superior interruption performance. In traditional circuit breakers, arc re-ignition is a difficult-to-avoid issue that often leads to secondary faults or even severe equipment damage. By contrast, the solid-state circuit breaker successfully avoids this problem through advanced interruption techniques, thereby providing strong support for the stable operation of power systems.

(2) Temperature Rise Test
Thermal performance is another key factor in evaluating solid-state circuit breakers. To effectively assess the device's heat dissipation capability during prolonged operation, a temperature rise test was conducted. The prototype was required to operate continuously for 24 hours, during which significant heat was generated [9]. After the test, temperature sensors were used to measure the prototype's temperature. The results showed a temperature rise of ΔT = 32 K. This data confirms the effectiveness of the hybrid cooling solution combining evaporative cooling and forced air cooling. By integrating the natural heat dissipation principle of evaporative cooling with the forced convection of forced air cooling, the system efficiently dissipates heat generated during operation, ensuring the device remains within an acceptable temperature range. Good thermal management not only ensures stable operation of the solid-state circuit breaker but also extends its service life.

(3) Lifetime Test
Service life is a critical indicator for determining whether a solid-state circuit breaker can be widely applied in real power systems. Therefore, to verify its lifespan performance, the prototype underwent an endurance test of one million operational cycles. Throughout the test, personnel closely monitored changes in the contact resistance of the prototype. After the test, contact resistance was measured and found to have changed by less than 5%. This result validates the effectiveness of the long-life design of the permanent magnet isolator switch. Even after prolonged and frequent operations, the switch contacts maintain excellent conductivity, ensuring reliable on/off functionality of the solid-state circuit breaker.

4 Conclusion
In summary, this paper presents a technical solution for low-voltage DC solid-state circuit breakers based on in-depth research into key technologies, including optimization of wide-bandgap devices, intelligent control algorithms, and high-reliability structural design. Experimental validation shows that the developed prototype achieves leading performance in key indicators such as interruption speed, fault detection accuracy, and operational lifespan.

It successfully realizes microsecond-level fast interruption and a million-cycle operational life, providing a practical and feasible solution for protection in new energy power distribution systems. Looking ahead, there are many promising research directions for low-voltage DC solid-state circuit breakers. For example, establishing a device-packaging-system level integrated simulation model could more comprehensively simulate the performance of solid-state circuit breakers under various operating conditions, thereby providing more accurate theoretical support for design optimization.