低压断路器智能控制装置可靠性研究

Investigation on reliability of intelligent trip device for LV circuit breakers

结合研制的基于液晶显示红外遥控智能控制装置 ,分析了在实际应用中出现的主要干扰和故障情况 ,从硬件与软件两方面着手 ,提出相应措施以提高低压断路器智能控制装置可靠性。这些措施包括采用空芯互感器作为电流互感器 ,配合自动切换分量程放大电路 ,以及相应的软件处理 ,提高大范围电流测量精度 ;采用复式电源双路供电 ,一路故障 ,另外一路自动切换 ;采用红外遥控操作 ,代替键盘操作 ,避免按键产生电火花 ,使其在有易燃、易爆危险气体等场合更安全 ;系统硬件故障自诊断 ,发生故障及时报警 ;电流过载保护时 ,计时具有热记忆特性 ;系统参数掉电保护 ;数字脱扣和模拟脱扣相结合 ,保证脱扣动作的及时与可靠 ;在线模拟测试各项系统功能。装置已投入现场使用 ,运行良好 ,具有很高的可靠性。

With the development of intelligent control device based on infrared control and LCD for LV breaker,the main interference and faults occurred in appilications are analyzed.The countermeasures in both HW and SW are proposed to improve its reliability.The hollow transformer is adopted as CT,the amplifier circuit with automatic measuring range switching and cooperated with related software is used to increase measuring accuracy.There are two power supplies working in redundant mode,the infrared control substitutes keyboard operation to avoid electric spark for hazardous working environment,the system hardware self- diagnosis function sets alarm in time when fault occurs.The time counting for overcurrent protection has thermal memory feature and the system parameters are saved during power shut down.The digital trip combined with the analog trip ensures proper and due action.The system functions are on-line tested.The device is properly running on cite with high reliability.