电能计量装置在线校验的精密传感理论与方法研究

The current calibration methods for electric energy metering device are the calibration when the power supply is interrupted. That is, the power of the line is powered off at regular intervals, and the equipment under test is withdrawn from the power grid and then calibrated. This method is not only complex, but also against the optimum utilization of the equipment. Therefore, to ensure the reliability of electric energy metering device, the online calibration principle and technology when the power line is energized should be researched. The precise sensing theory and method of online calibration for electric energy metering device in this project, is using the optical electric field sensors to measure the primary voltage, with the method of multi-point symmetrically arranged and the structure of clamp-shape. Then the power line voltage can be measured precisely without power off. Meanwhile, by using the transforming characteristics of the clamp-shape current sensors, the accuracy of the sensors can be diagnosed automatically, and then the primary current can be measured precisely. Through the modeling analysis and test, the influence to the sensors which caused by temperature change, line position, and the electromagnetic field of adjacent line, can be compensated effectively, and the accuracy can be improved. The online calibration method proposed in this project, not only can realize flexible and convenient online calibration for existing metering device, but also can promote the development of measurement theory and technology. The project has important theoretical and application value.

目前电能计量装置的校验方式普遍为停电状态下的校验：即每隔一定时间，线路停电，将被测设备从系统中退出后进行校验。这种方式不仅操作复杂，而且不利于设备的最优化利用。因此，需要研究能对计量装置进行不停电状态下在线校验的原理和技术，以保证电能计量装置的运行可靠性。本项目提出的电能计量装置在线校验的精密传感理论与方法，利用光学电场传感器测量一次电压，采用多点对称电场测量的方式，将整个传感器设计为“钳形”，从而实现不停电状态下线路电压的准确测量。同时，利用钳形电流传感器的传变特点，实现测量前传感器准确度的自诊断，达到一次电流准确测量的目的。项目通过建模分析和试验测试，研究温度变化、导线位置、附近电磁场等对传感器的影响，并设计相应的补偿方法提高测量准确度。本项目提出的在线校验方法，既可以实现对现有计量装置灵活方便的在线校验，还可以促进测量理论和技术的发展应用，具有重要的理论和实用价值。

校验是保证电能计量装置性能的必要环节。目前电能计量装置的校验方式普遍为停电状态下的校验，如互感器校验、电能表校验等。停电校验方式操作复杂、成本高。因此，需要研究能对计量装置进行不停电状态下在线校验的原理和技术，以保证电能计量装置的运行可靠性。本项目针对电能计量装置在线校验的精密传感理论与方法进行了分析研究，重点研究了以下几个方面的内容：针对电流测量提出了基于气隙校正的一次电流测量方法，可实现一次电流的准确在线传感，有效降低了气隙干扰；针对电压测量提出了基于标准传感装置与自动升降装置相结合的电压在线传感方法，以及基于电场传感阵列的电压在线测量方法，利用光纤采集传输系统有效保证了在线校验的安全；提出了高精度的数字积分算法，用于电流传感器输出信号的积分；提出了基于改进卷积窗的高精度信号处理算法，有效抑制了在线校验时信号频率波动及谐波干扰的影响；完成了样机研制及测试工作。本项目提出的在线校验方法，可以实现对现有计量装置灵活方便的在线校验，大大简化了检修流程，降低校验成本，具有重要的理论和实用价值。