基于精密分压与多级滤波的通信电源电压监控与保护系统

A Voltage Monitoring and Protection System for Communication Power Supplies Based on Precision Voltage Division and Multi-Stage Filtering

摘要: 本文针对通信电源在多路整流模块并联供电条件下易出现的电压跳变、支路串扰和监控误差累积问题，提出了一种基于STM32F103C8T6的高精度电压采集与快速保护系统。针对并联系统因模块电压不一致引起的电流再分配及电压跳变，设计中在各整流模块输出端串联阻塞二极管，实现支路电气隔离，从源头降低反向干扰并提升采样稳定性。系统通过精密分压和多级滤波完成高精度采样，抑制开关电源与整流器带来的高频噪声，并结合滞回比较策略实现可靠的过压判定，避免误触发。监控模块比较滤波电压与阈值，当电压超出设定阈值时，MCU导通三极管驱动继电器，使分励脱扣器切断空气开关，实现毫秒级断电保护，并通过续流二极管保护继电器，同时支持多通道电压监控与独立阈值配置。实验结果表明，系统在40~70 V区间测量精度达到0.017 V，继电器动作时间保持在0.02~0.04 s，能够满足通信电源在复杂工况下对实时性、稳定性与可靠性的需求。

Abstract: This paper proposes a high-precision voltage acquisition and fast protection system based on the STM32F103C8T6, addressing issues such as voltage jumps, branch crosstalk, and cumulative monitoring errors that often occur in communication power supplies under multi-channel parallel rectifier module configurations. To tackle current redistribution and voltage jumps caused by inconsistencies in module voltages in parallel systems, the design incorporates series blocking diodes at the output of each rectifier module, achieving branch electrical isolation, reducing reverse interference from the source, and improving sampling stability. The system achieves high-precision sampling through precise voltage division and multi-stage filtering, suppressing high-frequency noise from the switching power supply and rectifiers, while implementing reliable overvoltage determination using a hysteresis comparison strategy to prevent false triggers. The monitoring module compares the filtered voltage against a threshold; when the voltage exceeds the set threshold, the MCU turns on a transistor to drive a relay, enabling the shunt trip to cut off the circuit breaker and providing millisecond-level power-off protection. The relay is also protected by a freewheeling diode. The system supports multi-channel voltage monitoring and independent threshold configuration. Experimental results show that the system achieves a measurement accuracy of 0.017 V within the 40~70 V range, with relay action times maintained at 0.02~0.04 s, meeting the requirements for real-time performance, stability, and reliability of communication power supplies in complex operating conditions.