变压器是变电站中的重要设备，随着数字化变电站和智能电网的迅速发展，对变压器监测时实现高精度参数采集、智能化冷却控制已成为电力事业发展的必然趋势。本文从电力监测产品的实际项目出发，为提高变压器智能监控装置中模拟量采集板的采集精度，首次将基于FPGA实现的过采样技术应用于模拟量采集板。通过过采样技术减小量化噪声、提高ADC的信噪比来提高N位ADC的分辨率，既可以权衡分辨率与速度的最佳，又可以减少ADC成本，同时，还可以精简采样前的抗混叠模拟滤波器，降低硬件电路设计的复杂性。 对于过采样技术在变压器智能监控中的应用，本文主要做了如下工作：首先，以FPGA为控制器，根据需要选取合适的ADC芯片、总线收发器芯片来设计模拟量采集板的硬件电路。其次，在FPGA内实现过采样技术提高有效位数，主要工作包括：用状态机实现ADC16倍过采样的时序控制；采用乒乓操作降低数据处理对时序的要求；采用窗函数设计法，选择海明窗并用modelsim软件计算滤波器系数，利用FPGA本身的查找表结构，采用分布式算法设计FIR低通滤波器，将FIR滤波器中关键的乘法运算转化成查找表过程和加法过程，同时还对查找表规模大的缺点进行优化，节省硬件资源并提高运行速度。然后，完成与监控板的通讯；最后，对过采样前后两组结果做对比分析，进行性能验证。 结果表明，过采样技术提高了变压器智能监控系统的采集精度。因此，我们可以将过采样技术应用于各类采集系统来提高低精度ADC的分辨率。

The transformer is the important equipment in the substation, as the development of digital substation and smart grid, the high precision acquisition of parameters and the intelligent cooling control has become the inevitable tendency of power career when the transformer is monitored . Considering the actual project of electric power monitoring products, in order to improve the acquisition accuracy of the analog acquisition board in the intelligent monitoring of the transformer ,this paper tells how to apply over sampling technology based on FPGA to analog acquisition board first time .By reducing quantization noise and increasing signal noise rate of the ADC, over sampling technology can increase the resolution of N bit ADC. This can not only balance the optimum between resolution and speed but also reduce the cost of ADC. At the same time, it can simplify the anti aliasing analog filter before sampling, decrease the complexity of hardware circuit design. This work is mainly about the application of over sampling technology on intelligent monitoring of the transformer. Firstly, FPGA is the controller, proper ADC chip and bus transceiver chip are selected as needed, and hardware circuit of sampling module is designed .Then, achieve that effective bit in FPGA is increased by over sampling, the main work includes as follow, sequence control for sixteen rate over sampling is achieved by state machine. Pingpang operation is designed to decrease requirement for sequence. Window function method and kaser window are used to calculate coefficients by modelsim software.Distributed algorithms is applied to design FIR low pass filter to turn the key multiplication into LUT process and the addition based on the LUT structure of FPGA and the disadvantage of LUT is optimized ,which can save hardware resource and improve hardware running speed. Next, accomplish communication with monitoring board. Finally, the results of over sampling before and after are analysised and the performance is verified. The results show that over sampling technology improved acquisition accuracy of intelligent monitoring system of the transformer. So, over sampling technology can be applied to all kands of acquisition systems for improving the resolution of the low precision ADC.