【摘要】 该文开发了用于DC 1 500 V光伏和储能系统的新一代两极直流塑壳断路器样机。通过DC 1 500 V/15 kA，时间常数10 ms的短路分断实验发现，电弧电压快速升至350 V是提升断路器限流和分断性能的关键。为了加快初始燃弧阶段电弧运动速度使弧压快速上升，建立了断路器触头区域的二维局部电弧磁流体仿真模型，通过分析灭弧室温度、压力分布和气流速度变化曲线，明确了初始样机中电弧运动停滞的机理，并以此为依据提出了参差栅片排布和添加导流锥的气道优化设计方案。使用优化后的样机进行分断实验，比较优化前后的电压变化曲线和电弧运动高速摄像，验证了优化方案的有效性，对于DC 1 500 V两极直流塑壳的设计开发具有很强的实践指导意义。更多还原

【Abstract】 Solar photovoltaic, wind farms and many other new energy power generations are developing rapidly in China to realize the ‘Carbon Peaking and Carbon Neutrality Goals’. Especially the 1 500 V PV power generation solution gains the most attention because of its high energy density and efficiency. Due to the increment of the system voltage level, system protection for a short circuit also becomes more difficult. However,there is still a vacancy of a reliable, compact, and inexpensive DC circuit breaker for the DC 1 500 V PV systems,and quadrupole-series AC circuit breakers are used as a temporary stand-in for customized DC circuit breakers,which brings large volume and mass heat generation.Therefore, a new-type two-pole DC molded case circuit breaker prototype is developed for PV and energy storage applications. The distribution of all the components is changed, and the arc chambers and contact gaps are placed along the longest side of the circuit breaker to use as many arc chutes as possible in every single pole for the high-voltage arc extinction. Although the new structure theoretically improves the breaking capacity of the single poles with a very compact volume, the small dimension also limits heat dissipation and gas flow, finally limiting arc cooling and extinction. Hence, designing an appropriate arc chamber to realize smoother gas flow and faster arc movement is critical to developing the new DC 1 500 V two-pole circuit breaker.Firstly, experiments of DC 1.5 kV/15 kA with a time constant of 10 ms are carried out. It is found that the speed of arc voltage climbing to 350 V greatly affects the performance of the current limiting and interruption of the circuit breakers. To accelerate the arc movement and arc voltage increment, a 2-D arc magneto hydrodynamics(MHD) model of the contacts part is built to calculate the temperature, pressure distribution, and the fluid velocity variation. The simulation results indicate that the mechanism of arc immobility is the gas blocking between the contacts and the inlet of the arc chamber. Irregularly distributed arc chutes are proposed to release the pressure in the blocking area. There is enough space for the arc to accelerate after its generation to gain enough speed to rush into the arc chutes. Experiments and high-speed movies are carried out to verify the optimization. The irregularly distributed arc chutes release the pressure between the contacts and the arc chamber,making the arc flow into the arc chutes smoother.Furthermore, it is also found that the gas flow is blocked at the outlet of the arc chamber because the gas flow has to swerve sharply here to move forward to the circuit breaker vent. A flow diversion cone is introduced into the arc chamber to guide the flow forcibly and to release the pressure at the outlet of the arc chamber.Experiments are also conducted to verify whether the optimization works. The arc voltage waveforms and the film taken by a high-speed camera show that the flow diversion cone positively affects the arc movement. This paper has great practical meaning in developing the new-type DC 1 500 V two-pole circuit breakers.更多还原