新一代运载火箭附加系统温度测试台过压保护设计

(1．Shanghai Institute of Aerospace System Engineering, Shanghai 201100, China;2.Shanghai Institute of Aerospace Computer Technology,Shanghai 201100, China;

摘要:

本文针对XX-6运载火箭附加系统温度测试台在实际使用中因外部28V高压误输入导致核心模数转换芯片(ADS1220)烧毁、测量通道失效的故障,开展系统性的过压保护设计与可靠性提升研究。研究首先通过故障复现与机理分析,确认了原设计方案在输入端口异常电压防护方面存在设计盲区。在此基础上,提出了两种具有工程适用性的过压保护方案:其一为基于超低漏电流肖特基二极管的钳位限压方案,通过在信号前端增设无源保护电路,将异常输入电压强制钳位在-0.4V~3.7V的安全区间；其二为基于高耐压器件的本质安全方案,采用耐压达40V的恒流源(LM134)与耐压达36V的仪表放大器(INA188)重构信号调理链路。研究对两种方案的保护机理、电路设计及对系统测量精度、线性度、稳定性的影响进行了详细的理论分析与实验验证。结果表明,方案一可快速、低成本地实施,有效防护高压冲击,但会引入约±0.35K的测量误差(仍满足≤±0.5K指标)及千分之二的线性度损失；方案二则能在承受高压冲击的同时,保持优异的测量性能(误差≤±0.18K,线性度达万分之五),实现无损自恢复。基于“分类施策、纵深防御”的原则,本文进一步制定了在役设备基于方案一的模块化快速返修策略,以及面向新型号采纳方案二为核心并融合多级防护的系统性设计改进指南,同时提出了覆盖设计评审、过程控制、测试验证及使用维护的全流程可靠性提升措施。本研究不仅解决了特定故障,更为航天地面测试设备应对复杂电磁环境与人为误操作风险,提供了从故障分析、方案设计到工程实践的一整套理论方法与技术途径。

Abstract:

This paper addresses the overvoltage protection design and reliability enhancement for the CZ-6 launch vehicle’s auxiliary system temperature test bench, following field failures caused by the accidental intrusion of 28V high voltage, which burned out the core analog-to-digital converter (ADS1220) and disabled measurement channels. Through fault recurrence and mechanism analysis, the study first identified a design gap in protecting the input ports against abnormal voltages in the original scheme. Two engineering-feasible overvoltage protection solutions are proposed. The first is a clamping and limiting solution based on ultra-low leakage Schottky diodes, which employs a passive protection circuit at the signal front-end to forcibly clamp abnormal input voltages within a safe range of -0.4V to 3.7V. The second is an intrinsically safe solution based on high-withstand-voltage components, reconstructing the signal conditioning chain with a constant current source (LM134, 40V rating) and an instrumentation amplifier (INA188, 36V rating). Detailed theoretical analysis and experimental validation were conducted on the protection mechanisms, circuit design, and their impacts on system measurement accuracy, linearity, and stability. Results show that Solution #1 can be implemented rapidly and at low cost, effectively protecting against high-voltage transients, but introduces a measurement error of approximately ±0.35K (still meeting the ≤±0.5K specification) and a linearity degradation to 0.2%. Solution #2 can withstand high-voltage intrusion while maintaining superior measurement performance (error ≤±0.18K, linearity 0.05%), achieving non-destructive self-recovery. Guided by the principle of "targeted strategies and defense-in-depth," this paper further formulates a modular rapid repair strategy for in-service equipment based on Solution #1, and a systematic design improvement guideline for new models, advocating Solution #2 as the core architecture integrated with multi-level protection. Comprehensive reliability enhancement measures covering design review, process control, test validation, and operational maintenance are also proposed. This research not only resolves a specific failure but also provides a complete set of theoretical methods and technical pathways—from fault analysis and solution design to engineering practice—for aerospace ground test equipment to mitigate risks from complex electromagnetic environments and human operational errors.