Study On Top Shaking Control Systems Of Electrostatic Precipitator

ESP(Electrostatic Precipitator) plays an important role in environmental protection which key technique is the top control shaking. The model and law of top shaking control systems provide the theory basis for optimization and application of ESP, and they are also the key factors to design high performance ESP equipments. Based on the detailed analysis of the electrostatic stress model of the charged mill dust in migration progress, the adsorption affinity model of mill dust, the shaking accelerated speed model of mill dust,the motion model of the top shaker and a new PWM(Pulse Width Modulation) control theory, we adopt the embedded technology in our experiments and have designed a model ESP machine. Main results are summarized as follows.(1) By building a mathematic model about the mill dust, we discuss the electrostatic stress of mill dust when it is advancing; Besides, the analysis of the adsorption affinity of mill dust and the mathematic model of the shaking accelerated speed are applied to investigate the law of the shaking accelerated speed varying with the adsorption affinity of mill dust.(2) A mathematic model for three different moving stages of the top electromagnetism shaking hammer is established. We provide an energy-saving-shaking technology and get the law that the current flow in stator coil should satisfy the effective effect of the electric magnetic, that is, the effective height of the shaking hammer can't lift with further increasing the period of impulse current. On the contrary, it causes the saturated magnetization in stator coil which leads to the coil too heat to waste electric energy.(3) To improve a varying precision of the current in stator coil and the accuracy of lifting height with shaking hammer, we presented a new non-uniform PWM control technology and applied to top shaking control systems. The more precision averaging output voltage can be gained when the PWM impulse with much smaller stepping accuracy duty ratio applies to the stator coil.(4) According to the theory of resonance of energy storage elements and energy transfer, a new style passive resonance soft switch technology is presented. Depending on the resonance process, the shift of voltage and current occurs when the switch tube was broken over and shut off. Thus, soft switch technology satisfies the condition of ZCS(Zero Current Switch) and ZVS(Zero Voltage Switch), which gives the result of non-destructive switch, decreases energy consumption and protects the power switching transistor.(5) A new style matrix allocation control circuit with line & array and hardware current feedback circuit is designed. We adopted a simple method to control the complicated matrix and solve the problem of common break-over to distributing of control signal at the same time. A graphic input technology of multi-parameter and multi-model with independent intelligent property right is explored. It makes the input and modification of the live parameter more visually, more conveniently.In the end, we made a summary on my paper and had an outlook on my future research.