Popis: |
With the application of inverter in high-voltage motor, the traditional current differential protection cant be used because of the variable frequency. So it adopts low sensitive current instantaneous protection as main protection, which doesnt meet the security standard of grid state. In order to improve the sensitivity and reliability of high-voltage motor protection, a new method based on current sampled values is proposed in this paper, which adapts to the variable frequency system. After a brief description about the impact of inverter on main protection of motors, it introduces the principle of sampled value current differential protection and variable RS sampled value algorithm. A matlab example is used to simulate. On the whole, the simulation and analysis of the calculation results verify the feasibility and reasonableness of the method. Therefore, it provides a new approach for the protection of high-voltage motor in variable frequency system. |