Studies Of Error Characteristic And Design Of Resistance Voltage Sensor

Electromagnetic voltage transformer and capacitance divider are usually used to get voltage signal in power system. For the former has inductance winding and ferromagnetic material, its measurement range is restricted by saturation, so it has a narrower range of frequency. Being an inductance, it has the possibility of resonance. Also the capacitance divider has the possibility of resonance with inductance component in the system, which can make a heavy over-voltage and endanger the running of equipments and power system.By adopting resistance divider, voltage sensor designed in this topic has no ferromagnetic resonance, overcome saturation, has no load sharing, and is permitted to short and cutoff in circuit, so it has high reliability. By contrast with traditional voltage transformer, it has advantages of smaller volume, lighter weight, simpler structure, wider range of frequency, and no resonance. Only one can fulfill both functions of measurement and protection. The same for no resonance, its capability is better than capacitance divider. A voltage sensor we designed is to be used in 1 OkV grade system.In this topic, the error characteristic of resistance voltage sensor was analyzed in theory, by using electric circuit analysis, the reasons which affected its error were gotten. Based on theory analyses, initial structure was designed. Then by using FEM (finite element method) of simple resonance field, several structures electromagnetic field was calculated, and their amplitude errors, phase errors, maximum of electric field intensity and frequency characteristic of amplitude error were contrasted. Then the best structure was gotten. A sample of designed resistance divider was also made, and several tests were done. At last the initial design of electronic part was made, some methods of resisting electromagnetic interfere were put forward too.