Research On New Integrated Voltage And Current Transformer Based On Slice Induced Voltage Measurement Method

In the power system,current and voltage measurement is the most important part of the power system energy measurement and relay protection device design.At present,traditional current transformers and voltage transformers are the most commonly used current and voltage measuring devices in power systems.However,there is an over-voltage problem in the measurement process of the traditional voltage transformer,and the measurement process of the traditional current transformer is prone to magnetic saturation,which leads to inaccurate measurement.Based on the consideration of equipment integration,the current-voltage integrated transformer can measure current and voltage signals at the same time,which not only saves equipment costs,but also obtains more measurement information at the same time.However,current and voltage integrated transformers also have some problems.Among them,the optical current-voltage integrated transformer is susceptible to interference from the external environment due to the sensitivity of optical materials,and the measurement accuracy is low.However,due to the compactness of its own structure,the combined current and voltage transformer is seriously affected by its own internal interference,and the measurement stability is low.In view of the above-mentioned problems,this thesis proposes a new voltage measurement method,and designs a new current-voltage integrated transformer based on the basic structure of a 220kV inverted SF6 current transformer.This article describes the principle of new voltage measurement,establishes a voltage measurement electromagnetic simulation model based on the structure of 220kV current transformer,verifies the accuracy of the new voltage measurement model,obtains the equivalent circuit of the voltage measurement model,and analyzes the sensor slice The influence mechanism of parameters such as size,gap,measuring resistance and capacitance on voltage measurement is studied.The influence mechanism of electromagnetic interference such as lightning and electric fast pulse on voltage measurement is studied.Finally,through simulation research and analysis,it is found that the gap insulating medium affects the accuracy of the voltage calculation by affecting the sensor capacitance parameters;the size of the sensor slice can also affect the accuracy of the voltage measurement method;the size of the measurement resistance can affect the sensitivity of the voltage calculation;electromagnetic interference It is easy to have a destructive effect on the voltage measurement device;the influence of electromagnetic interference on the voltage measurement can be reduced by adding an appropriate artificial capacitor.After optimizing the parameters of the slice voltage sensor,the new current-voltage integrated transformer proposed in this paper has the characteristics of strong anti-interference ability,high measurement accuracy and strong sensitivity in voltage measurement.Through the study of new voltage measurement methods in this paper,a new type of current-voltage integrated transformer formed by combining the current measurement of the current transformer itself has laid the foundation for the field of current and voltage measurement.