Novel three-phase power frequency IGBT pulse width modulation high-voltage power supply for electric precipitation

Abstract

The invention relates to a novel three-phase power frequency IGBT pulse width modulation high-voltage power supply for electric precipitation. The novel three-phase power frequency IGBT pulse width modulation high-voltage power supply comprises a main loop, three paths of IGBT triggers, a high-voltage power supply controller and a current and voltage sampling circuit. The main loop is composed ofthree paths of three-phase IGBT anti-parallel circuits, wherein one end of each path of three-phase IGBT anti-parallel circuit is connected with the input end of an external three-phase power supply,the other end of the three-phase IGBT anti-parallel circuit is connected with the input end of a three-phase boosting rectifier transformer, three pins of each IGBT are connected with the IGBT triggers, and the three paths of IGBT triggers are all connected with the high-voltage power supply controller. According to the invention, the IGBT is used as a main loop control device, and the region nearthe sine wave peak value is selected to be conducted, so that reactive power output in the region near the sine wave zero crossing point can be avoided, the same load peak voltage can be obtained, and the power consumption can be greatly reduced; and when spark flashover occurs to the electric precipitation load, the IGBT can be turned off immediately, the flashover transient impact current is greatly reduced, and the electric corrosion influence of the flashover impact current on the discharge tip of the cathode wire is avoided.

Description

technical field [0001] The invention relates to the field of electric dust removal, in particular to a novel three-phase power frequency IGBT pulse width modulation high voltage power supply for electric dust removal. Background technique [0002] The working principle of a conventional electrostatic precipitator is to alternately arrange multiple rows of anode plates and cathode lines inside the shell to form an electric field. The cathode line is supplied with a negative high-voltage direct current from a high-voltage power supply, and a negative high-voltage electric field is formed around the discharge tip of the cathode line. The anode After the plates are connected to the shell, they are grounded together. When the industrial flue gas passes through the anode plate and the cathode wire to form an electric field channel, the dust particles in the industrial flue gas will be ionized and charged with negative charges, and then migrate towards the anode plate under the acti...

AI Technical Summary

Problems solved by technology

However, since the three-phase AC is alternately superimposed and turned on, the phase difference of each phase is 120°. When the flashover discharge occurs in the A phase, the B phase is already in the conduction state before the phase commutation at the zero-crossing point of the thyristor, which is equivalent to "on fire" Oil pouring” lasts until the zero-crossing phase of phase B is changed, and the output can be completely shut down and blocked. The instantaneous current of the flashover impact may be as high as 3-5 times. For the equipment signal sampling interference impact and the electric erosion of the discharge tip of the cathode line are large and are very disadvantageous

Secondly, since the concentration of dust flowing through the electrode electric field after electrostatic precipitator is getting smaller and smaller, if the complete full-wave operation mode continues to be used, the electric field is close to the no-load state, the current reaches the rated value, but the actual output voltage decreases step by step, and the energy consumption Larger and larger, the charge and dust removal for fine dust will decrease

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