94 / 2024-04-11 21:54:24

Research on a Permanent Magnet Trip Device for DC Miniature Circuit Breakers

miniature circuit breaker,permanent magnet tripper,dynamic and static characteristics,simulation analysis

In recent years, with the rapid development of low-voltage power systems, the demand for the performance of low-voltage switching devices has also shown a growing trend. As a switching device widely used in low-voltage areas, the miniature circuit breaker has demonstrated excellent performance in circuit short-circuit protection, playing a crucial role in ensuring the stability and safe operation of the power system. Among them, the magnetic tripper, as a key component for realizing instantaneous tripping actions in short-circuit protection, has a direct impact on the protection effect of the miniature circuit breaker in terms of its performance and reliability. Therefore, research on magnetic trippers is of great significance for improving the short-circuit protection performance of miniature circuit breakers.近年来，随着低压电力系统的快速发展，对低压开关器件性能的要求也呈现出日益增长的趋势。微型断路器作为一种广泛应用于低压地区的开关设备，在电路短路保护方面表现出优异的性能，对保证电力系统的稳定安全运行起着至关重要的作用。其中，磁性脱扣器作为短路保护中实现瞬时脱扣动作的关键部件，其性能和可靠性直接影响微型断路器的保护效果。因此，研究磁脱扣器对提高微型断路器的短路保护性能具有重要意义。



This article focuses on the study of a permanent magnet tripper used in DC miniature circuit breakers, which adopts a scheme of setting a permanent magnet opposite to the moving iron core to replace the traditional tripper built-in spring scheme. The three-dimensional modeling software is used to establish a virtual prototype simulation model of the permanent magnet tripper. Based on national standards, the coil current is set to three times the rated current as a constraint condition for non-action. Through virtual simulation software, the shape and size of the permanent magnet and the relative position of the permanent magnet and the moving iron core are determined. The action process of the permanent magnet tripper is simulated and calculated, and the dynamic and static characteristic curves of the permanent magnet tripper are obtained. Key parameters such as electromagnetic suction force and tripping time are analyzed in detail, and a thorough comparison is made with traditional tripper. The comparison of simulation results between the two shows that when a short-circuit current occurs in the circuit, the permanent magnet tripper can perform tripping actions accurately and quickly in a shorter time compared to traditional tripper, ensuring the efficient and stable operation of the miniature circuit breaker and quickly and effectively cutting off the faulty circuit.本文重点研究了一种用于直流微型断路器的永磁脱扣器，该脱扣器采用永磁体对动铁芯设置的方案，取代了传统脱扣器内置弹簧的方案。利用三维建模软件建立了永磁脱扣器的虚拟样机仿真模型。根据国家标准，将线圈电流设置为额定电流的三倍作为不动作的约束条件。通过虚拟仿真软件，确定永磁体的形状、尺寸以及永磁体与动铁芯的相对位置。对永磁脱扣器的动作过程进行了仿真计算，得到了永磁脱扣器的动、静态特性曲线。详细分析了电磁吸力、脱扣时间等关键参数，并与传统脱扣器进行了比较。两者的仿真结果对比表明，当电路中出现短路电流时，永磁脱扣器比传统脱扣器能在更短的时间内准确、快速地执行脱扣动作，保证了微型断路器的高效稳定运行，快速有效地切断故障电路。



In order to further verify the accuracy of the simulation calculation, the instantaneous tripping test is carried out on the miniature circuit breaker equipped with permanent magnet tripping device and traditional tripping device.The repeated test results show that under the same short-circuit current condition, the permanent magnet tripper can trigger the tripping action more quickly than the traditional tripper, has obvious advantages in the tripping time, and shows higher action stability, which can effectively realize the protection of the circuit and prevent the short-circuit current from causing further damage to the power system.为了进一步验证仿真计算的准确性，对配备永磁脱扣装置和传统脱扣装置的微型断路器进行了瞬时脱扣试验。反复试验结果表明，在相同短路电流条件下，永磁脱扣器比传统脱扣器能更快触发脱扣动作，在脱扣时间上具有明显优势，且表现出更高的动作稳定性，可有效实现对电路的保护，防止短路电流对电力系统造成进一步的破坏。