张晨+凌跃胜

摘 要： 传统DC?DC变换器故障检测系统只对变换器中某重要元器件进行故障检测，导致检测结果不准确。为此，设计了新的双向全桥DC?DC变换器故障智能检测系统。通过闭环霍尔电流传感器对电流信号进行采集，给出信号采集电路，通过分析双向全桥DC?DC变换器元件衰减过程提取故障数据，对不同故障状态样本进行采集，构建HMM模型，求出HMM模型初始参数，迭代参数直至其收敛到既定区间，对采集的电压、电流信号进行归一化处理，产生观察值序列，把观察值序列输入到训练完成的不同HMM模型中，求出相似或然率和相似或然率最大值相应的HMM模型，即为双向全桥DC?DC变换器故障检测结果。实验结果表明所设计系统检测准确性高。

关键词： 双向全桥； DC?DC变换器； 故障； 智能检测； 系统设计； 信号采集电路

中图分类号： TN710?34； TP277 文献标识码： A 文章编号： 1004?373X（2018）05?0144?05

Abstract： The traditional fault detection system of the bidirectional full?bridge DC?DC converter can only detect the fault of a certain important component in the converter， and its detection result is inaccurate. Therefore， a new intelligent fault detection system for bidirectional full?bridge DC?DC converter was designed. The current signal is acquired through closed?loop Hall current sensor. The signal acquisition circuit is given. The component attenuation process of bidirectional full?bridge DC?DC converter is analyzed to extract the fault data. The samples with different fault conditions are acquired. The hidden Markov model （HMM） is constructed， and its initial parameter is determined. The parameter is iterated until it is converged to the established section. The acquired voltage and current signals are normalized to generate the observing values sequence. The observing values sequence is input into different HMMs after training to get the similarity probability and the HMM corresponding to the maximum similarity probability， whose output is the fault detection result of a bidirectional full?bridge DC?DC converter. The experimental results show that the designed system has high detection accuracy.

Keywords： bidirectional full?bridge； DC?DC converter； fault； intelligent detection； system design； signal acquisition circuit

0 引 言

双向全桥DC?DC变换器是电力电子技术的关键，通过双向全桥开关DC?DC变换器技术组成的高频开关电源被广泛应用于电子通信和家用电器等领域[1?2]。开关是整个电子设备的基础，在出现故障的情况下会造成电子设备功能丧失，甚至会导致系统瘫痪，带来很大的损失[3?4]。因此，准确检测双向全桥DC?DC变换器故障非常关键，能够及时采取防御措施，降低维修周期和损失。

当前，针对双向全桥DC?DC变换器故障检测的研究主要是对变换器中某重要元器件进行故障检测，如通过卡尔曼滤波方法对电解电容器故障进行检测，通过高斯回归方法对变换器、滤波器故障进行检测[5]，因为双向全桥DC?DC变换器中不同元件具有负载型和容差等问题，导致上述方法在实际应用时均有局限性，不能有效实现双向全桥DC?DC变换器的故障检测。……