Anti-interference Analysis Of Measurement And Control Circuit Board In High Potential Area And Complex Electromagnetic Environment

As the voltage level of the power system rises and the widely applied of high-voltage and large-capacity devices and intelligent devices,the electromagnetic compatibility problems are increasingly prominent.Since the control and protection system of the equipment was in a high potential and complex electromagnetic environment,its reliability is challenged.On the other hand,with the development of flexible transmission,the electromagnetic environment in the converter valve hall has received extensive attention.The control circuit and the drive circuit of the sub-module are all in the high-potential areas in the valve hall,which are also affected by electromagnetic disturbance.Since the measurement and control circuits of series compensation and converter valves are in a high potential and complex electromagnetic environment,and the anti-interference ability of the circuit board is the key factor affecting the reliability.This thesis will take the series compensation and converter valves as an example and analyze the anti-interference ability of the measurement and control circuit board in the complex electromagnetic environment of the high potential area.This thesis has considered the transient processes of the series compensation platform,establishes the equivalent circuit of the series compensation system,and calculates the transient voltage and current of the series compensation platform under several ground faults.Then uses this model to reproduce a certain fault,the simulation results and the waveforms of the recorded waves are basically the same,which verifies the correctness of the model.Secondly uses the finite element integration software to establish a three-dimensional model,and simulates and analyzes the electromagnetic environment under the fixed frequency of the series compensation platform.The electric field of the fence at a height of 1.5m around the platform has calculated and it agrees with the national standard.Measures near-field disturbance of a 500kV converter valve,and obtains the near-field electric field in its background and five different states,and the electromagnetic disturbance of the board is evaluated.Finally,establishes the field-circuit coupling model and analyzes the influence of board layout and microstrip line size on port induced voltage under the same disturbance,based on the two-layer simple circuit board.Calculates the induced voltage of the ports under the far field disturbance,and analyzes the influence of different incident angles on the induced voltage.Calculates the ports induced voltage of the circuit board under the near field disturbance with the finite element integration method.And calculates the shielding effectiveness of the measuring box.