Power Quality Detection Device Based On Arm Hardware System Design And Implementation

In recent years,the modern energy grid and the composition of its load changes a lot due to the persistent growth of power electronic equipment,such non-linear,the frequently variable load does great harm to power quality of energy grid system,such as the voltage waveform distortion,flicker and harmonic power quality problems.At the same time,more and more electronic instrument and automation equipment is widely used and the other sensitive equipment are increasingly high requirements for power quality.Researching and designing the power quality detection for high-performance monitoring and analysising of power quality has a very important significance based the status of the growing problem of power quality and electrical equipment for power quality requirements.The thesis combines the status of domestic and international power quality testing instruments designed power quality detection devices based on ARM core micro-controller hardware system,the principal tasks for the design and implementation of the hardware system of power quality detection device debugging and improving the whole system.The thesis first summarizes the meaning, characteristics, and related indicators of power quality parameters according to our power quality standards and IEC standards, and describes the various parameters of the measurement model and its measurement principle. Then it improves the software synchronous sampling methods which are commonly used,studies the phase mismatch between the measurement channels in this article,and proposes the solution to ensure linear phase and the inter-channel phase compensation.Secondly, the hardware system of the energy detection devices based on ARM is designed in detail, including signal conditioning modules, the analog to digital conversion module based on the AD7606, the processing module based on S3C2440core and the system power supply module. Finally, the hardware circuit and the entire system are actually tested, the experiment results are analyzed and proposes improvements.The experiments show that this device can measure the basic parameters of the grid and have a high measurement accuracy,including the grid frequency, voltage/current rms, harmonic content, the total harmonic distortion and three-phase voltage unbalance.The voltage accuracy is about±0.5%,and the frequency accuracy is about±0.01Hz. High-order harmonic measurement accuracy could be improved.