With the development of the power grid, high voltage transmission lines and smart substations are put into use This requires higher-performance voltage transformers Potential transformer(PT) can no longer meet the measurement needs Analysis of the voltage measurement requirements in the power grid, pointing out the limitations of traditional PT such as poor insulation performance and ferromagnetic resonance The principles, characteristics and application of three new voltage transformers, that is, resistance voltage transformer, capacitor voltage transformer(CVT), and optical voltage transducer(OVT) are described, and the practical problems of new voltage transformers are summarized and put forward

Overview of Voltage Transformers Suitable for High Voltage Levels

In distribution network, single-phase fault is easy to cause the ferroresonance in potential transformer (PT), a compound elimination method of PT ferroresonance is proposed. Firstly, the principle of PT ferroresonance after single-phase fault is analyzed. Secondly, two ferroresonance elimination methods, including adding damping resistance at PT open delta winding and neutral grounding through resistance, are introduced. A compound elimination method of PT ferroresonance controlled by the insulated gate bipolar transistor (IGBT) is proposed. Finally, the PT ferroresonance model of 10kV distribution system is established by PSCAD/EMTDC software. The effectiveness of the compound elimination method of PT ferroresonance is simulated. The simulation results show that the proposed elimination method can effectively suppress ferroresonance.

Compound Elimination Method of Potential Transformer Ferroresonance in Distribution Network

This paper mainly discusses calculation on resonance over-voltage adopting describing function method in control theory, the pressure variable describes function in which makes the calculation procedure more easy. On frequency domain field, small parameter method in nonlinear vibration theory is referred to analyze resonant frequency, average method is used to analyze 1/3 resonant frequency.

He Na

Papers

Study on Ferromagnetic Resonance Over-voltage of Voltage Transformer