Application Of Dynamic Phasor Theory In Modern Power System Simulation

With the development of power grid and application of electronic device, the power systems are becoming more and more complicated. It also becomes more difficult to model and simulate power grid. Traditional"Quasi-stationary"phase models can't be used for studying electromagnetic transient phenomena; on the other hand, the EMTP models can be used to analyze the electromagnetic transient accurately, but for the limitation of the step size, it can't be used to simulate the large network with a high speed.The application of dynamic phasor is a new selection for power system simulation. This approach is based on the time-varying Fourier coefficient series of system variables. By neglecting the unimportant terms, the dynamic behavior of original detailed model can be retained. For using a larger step size, the dynamic phasor has higher efficient and speed.The numerical oscillation triggered by the changes of the network configuration will cause incorrect results in power simulation which can't be used to analyze electromagnetic transient accurately. In this dissertation, a new method is developed to eliminate the numerical oscillation caused by the changes of the network configuration. The dynamic phasor based on the critical damping adjustment (CDA) has the combined character of dynamic phasor, trapezoidal integrator and critical damping adjustment (CDA), so it not only can eliminate the numerical oscillation with good accuracy, but also can keep the conductance unchanged.The dynamic phasor model of three-phase distribution parameter lines is also developed in this dissertation. It breaks the quasi-stationary assumption, at the same time, overcomes the maximum step size constraint of regular transmission lines, so it can be used to simulate the fast electromagnetic transient phenomena at a higher speed. A novel large step size model based on the dynamic phasor is also introduced to accelerate simulation speed further.As for the electronic device, the dissertation developed a new model of static var compensator (SVC), which includes TCR branch, SVC control circuit and filter branch. The SVC dynamic phasor model focuses on fundamental and 5th harmonic wave while neglects the other unimportant harmonic waves. The simulation results demonstrate the dynamic phasor can be used to analyze the dynamic character of SVC and devices and network with non-linear components efficiently and accurately.In modern large scale power system,"Online simulation"and"Real-time simulation"are usually used to simplify and accelerate the simulation to break through limitation of dimension in calculation. This dissertation is devoted to the...