The CT analyzer is an indispensable instrument for on-site verification of current transformer accuracy. The traditional current transformer test method is mainly the measurement method. Due to the limitation of the principle, the on-site verification of the current transformer is extremely inconvenient. The CT analyzer designed and developed in this paper adopts a new indirect test method, the low-pressure method, which obtains the ratio and angular difference of the current transformer by measuring the internal parameters of the CT. According to the intelligent design method, combined with digital sampling technology, the DSP microprocessor is the core, and the advanced digital signal processing method is adopted. The on-site verification of the current transformer can be realized with only one instrument, which effectively solves the current mutual inductance. The problem of field testing.

The current transformer is one of the most important high-voltage devices in the power system. It is widely used in the current measurement and relay protection of power systems. Under normal operating conditions, the current transformer can ensure the accurate transmission of the current in the electrical circuit. change. However, since the current transformer is mainly composed of nonlinear electromagnetic components, the nonlinear components will adversely affect the transient response characteristics of the transformer, and even the saturation problem may cause the secondary side of the current transformer to fail to accurately reflect the primary current. Changes. Therefore, the analysis of the transient characteristics and residual magnetization of the current transformer ensures that its state and accuracy are important links to ensure the safe, reliable and efficient operation of the power system.

The CT analyzer is a must-have instrument for verifying the status and accuracy of current transformers. The early CT analyzer was a comparative type, that is, the secondary current of the standard and the tested transformer was separately input into the instrument, and the resistance element inside the instrument was converted into a voltage of the same nominal value, and then the

phase difference of the voltages of the two voltages was subtracted. It is converted into the ratio difference and phase difference of the tested transformer relative to the standard transformer. This kind of direct comparison calibrator, because the resistance component participates in the conversion, the error is the measurement error of the calibrator, so this calibrator can only be used to verify that the accuracy of the resistance component is one order lower than the accuracy of 0.1 or less. Precision transformer. Later, the CT analyzer developed into a differential type, which is to input the difference between the standard and the secondary current of the transformer to be input into the analyzer. The error of the internal components of the instrument is only the error of the instrument reading, that is, the error of the transformer. error. Such an analyzer can be used to characterize high-precision transformers