Research On Distribution PT Ferroresonance Based On The Theory Of Time-varying Vector

Ferroresonance overvoltage, which heavily impacts the security, stability and reliability of the system, is one of the inner overvoltage that always occurring in neutral isolated system and sometimes in neutral grounded system, and the mechanism, forecast and judement of PT ferroresonance trouble the power operators and technical experts. Based on the theory of nonlinear system stability and time varying vector the paper puts forward the PT ferroresonance criterion---Dynamic Response Characteristic Curve and Equal Area Criterion, which effectigvely forecasts the PT ferroresoance condition. The paper mainly makes a research from following respects:1. The paper establishes typical distribution PT ferroresonance model, and the ATP simulation software is used to restore PT ferroresonance accident. The 1-order,2-order and 0-order network of the distribution is set up based on phase-mode transformation theory; the paper also makes analyze on the two typical PT ferroresonance phenomena.2. Based on time varying vector theory, the 0-order network time varying mathematical model is build up, the Dynamic Response Characteristic Curve theory is advanced based on time varying mathematical model and nonlinear system stability, and the normal working point, the unstable equilibrium point and ferroresonance point.3. The Equal Area Criterion theory is put forward based on the Lyapunov Energy Function through the integration of current-flux linkage. Simultaneously, the concepts of disturbance size and stability margin are advanced. Lots of ATP simulations verify the effectiveness of the Equal Area Criterion theory.4. Typical ferroresonance braking measures are analyzed based on the Dynamic response and Equal Area Criterion theory. The paper also evaluates the advantages and disadvantages of the braking measures.In conclusion, the research on distribution PT ferroresonance based on the theory of time-varying vector effectively analyzes the physical mechanism, occurring and criterion conditions of PT ferroresonance. The paper also makes analysis to typical PT ferroresonance braking measures. Key words:Ferroresonance, Nonlinear System Stability Theory, Time Varying Vector Theory, Dynamic Response Characteristic Curve, Equal Area Criterion, Ferroresonace Braking Measures...