Hybrid Inter-phase Reactor Based On Single-phase Bridge PWM Rectifier Technology

Nowadays,power frequency AC rectifiers suitable for power grids have been widely used in the interfaces of various industrial production equipment and power grids.However,in the case of high power,due to the nonlinear characteristics of power semiconductor devices,there will be a large number of rectification processes.Current harmonics enter the power grid,causing pollution to the power grid.In most cases,the use of multi-pulse rectification technology can suppress current harmonics.The existing multi-pulse rectification is divided into passive harmonic suppression and active harmonic suppression.Passive harmonic suppression cannot be based on the principle.The above eradicate harmonics and the balanced reactor used has a complex structure.Although active harmonic suppression has a better effect on suppressing harmonics,its active link capacity is large,causing large damage and no ripple on the output voltage.To improve the effect,this article will combine the advantages of active and passive harmonic suppression,and use a hybrid harmonic suppression method to make it have the advantages of passive and active,while maintaining the current harmonic suppression effect while ensuring its active The capacity of the link is reduced and the output voltage ripple is low.Analyze the expression of the relationship between the input current of the conventional 12-pulse rectifier circuit and the circulating current on the side of the balanced reactor through mathematical methods,and use the three-phase symmetrical sine wave with the input grid current as the standard as the starting point to analyze the balanced reactor in this state Circulation current expression of,the waveform of the circulation is obtained.As long as the circulation is the waveform obtained above,the grid current can be obtained as a standard three-phase symmetrical sine wave.Combined with the principle circuit of the balanced reactor of the hybrid multi-pulse rectification,the principle of the hybrid harmonic suppression can be analyzed,and the effectiveness of the principle for the harmonic suppression of the input grid current can be verified by simulation.Based on the analysis of the principle of hybrid harmonic suppression,calculation and simulation are used to change the transformation ratio of the primary side of the balanced reactor,thereby changing the active and passive synthesis scheme.By inputting the harmonic content of the grid current in the simulation results The optimal selection of a series of parameters such as the capacity of the active part,the output voltage and the design capacity of the balanced reactor can determine the optimal transformation ratio of the balanced reactor that can achieve hybrid harmonic suppression,so as to analyze the theoretical optimum A hybrid solution of active and passive.Combining the principle analysis of hybrid multi-pulse rectification,design balanced reactor and single-phase bridge-type secondary active circuit,optimize the device parameters in the active circuit,and complete the hardware of the control circuit on this basis Design and software programming have verified the effectiveness of the hybrid multi-pulse rectifier circuit in suppressing the harmonics of the grid current through system experiments,and found out the best practical hybrid scheme through experiments,laying the foundation for practical industrial applications.