Modeling And Fault Simulation Of Multi-infeed System In Shandong Power Grid

Due to the growing demand for electricity in Shandong Province, Shandong electric power company took the implementation plan about the early electricity into LU. According to the related research,,the dynamic characteristics of multi-infeed systems is more complicated than single-infeed system, when the condition of the electrical contact is stronger, there may be significantly negative influence on the overall performance of the system, and even will threaten the security and stability of system running status. So far, most receiving end power grids were ideal model in the DC multi-infeed study, and this couldn’t reflect the dynamic characteristics of real grid. The so called dynamic characteristic is that the dynamic change of each parameter after system disturbing. The dynamic characteristics of multi-infeed systems include the change of ac voltage, ac current, ac power and dc voltage, dc current, dc power. Besides, the firing angle, extinction angle and VDCOL are also included.According to the overall modeling framework of Shandong power grid, this Paper established Yindong dc system model, Humeng dc system model and ac system model in MATLAB/Simulink; Model validation is an effective way to determine the model validity. There is a coupling relationship between multi-infeed systems. The mutual influence exists between each other, so the voltage and current characteristic in the multi-infeed systems are different from a single dc system. Then the paper validates the simulation model, and several ac faults are simulated.This paper summarizes the more into detail modeling, equivalent dc system fault in the power system simulation analysis, the commutation failure mechanism of the current state of research problems, points out the characteristics and disadvantages of the existing control and protection strategy for the future more feed in ac/dc hybrid power system research provides some reference opinions.