| It is essential to regulate the flow of the fans and pumps to meet some specific production requirements according to the actual situation. For most kind of the high power electric drive equipment, such regulation is usually achieved through the control of throttles and baffles. Though the principle of the mechanism is relatively simple, but it is always accompanied by a huge waste of energy and the performance is not so ideal. So it is of great theretical value and practical significance to study on the energy-saving and high-performance speed regulation drive technology.To solve the above problem, a rotor chopper speed control system for high-voltage and high power wounded rotor induction machine is proposed by adjusting the duty cycle of the boost converter. The dynamic mathematical model is derived with the analysis of the principle of the system. Then a model predictive control stategy is put forward based on Laguerre sequence, meanwhile, a hybrid filter pretreatment for current signal is utilized for filtering the strong noise and a rapid fault diagnosis based on determinatics learning theory for open circuit of interleaved boost converter. The real system is designed and implemented.The pricipal contents and results are as follows:1. By analysing the principle of the rotor speed of the chopper, the dynamic structure of the speed control system has been constructed. A mathematical model of the dynamic system is established to provide a theoretical basis for the control.2. In order to improve the performance of rotor chopper controlled of wound rotor induction motor to adapt the power fans to different conditions of demand for speed control, adaptive predictive control based on Laguerre function policy has been employed. Predictive control methods and object-based modeling based on Laguerre function sequence have been proposed, several adaptive predictive control algorithms have been designed roled as the speed regulator, simulation results indicate that using this control strategy can reduce the overshoot of rotor chopper speed control system, make the whole process smooth and fast, effectively improve the transient response and steady-state performance of the dynamic response of the system.3. The dynamic control model of multi-phase boost chopper circuit has been built and the total input current ripple characteristics and its slope change law under the normal state and the state of open-circuit fault of multi-phase boost chopper circuit have been found, that provide theory basis for successive fault diagnosis.4. Impacted by the severe electromagnetic interference the current signals contain many impulse noise and Gaussian noise, the hybrid digital filter combined median filter and average filter has been proposed, it can filter the impulse noise and Gaussian noise in the original signals. The hybrid digital filter is one of the necessary prerequisites to the successive signals process.5. The paper makes a research of the dynamic mode rapid fault diagnosis method based on definite learning theory to solve the problem of on-line fault diagnosis in one phase open circuit fault in the multi-phase interleaved boost chopper in parallel converter which is based on a single current signal. Using the total input current signal the method can rapidly diagnose an open circuit fault of the multi-phase boost chopper converter.The open circuit signal dynamic information of the multi-phase interleaved boost chopper converter can be drew by applying the definite learning theory and stored as the way as neural network constant weights. Dynamic estimator has been constructed by the dynamic information and the dynamic mode rapid fault diagnosis method is used to diagnose faults of the system. The simulation and experimental results show that the method by use of definite learning to trace and diagnose a fault in open-circuit fault diagnosis multi-phase interleaved boost chopper in parallel converter is rapid and effective.6. The drive signal of the multi-phase interleaved boost chopper in parallel converter is IGBT drive signal that is multi-channel and phase shift equalization. To solve the high-speed digital output shortage problem of PLC controller, a pulse distribution adapter has been designed and phase shift equalization and distribution of the single high speed PWM signal have been realized by the way of combining a crystal divider with series shift register. IGBT drive signal was transmited by optical fiber to meet the drive requirements of the boost chopper converter. In this way IGBT drive interference capability has been enhanced, thereby the circuit stability of speed control system has improved.7. For the slow process speed of PLC to a high voltage high current IGBT drive fault signal, fiber failure signal determination circuit with ns stage processing speed has been designed. It can parallelly and high-speed identificate fault signals of multi-channel IGBT optical fiber, IGBT drive signal can be turned off as soon as fault detection, so effective solution to the slow process speed of PLC to a fault signal has been implemented, thereby the probability of high-power IGBT damage reduces.8. In terms of the problem that high-power DC busbar stray inductance is too big, finite element software has applied to simulate and analyze the impact that interlayer spacing, layout and other factors of laminated busbar on the stray inductance size, so a low inductance laminated busbar design has achieved. For high-power IGBT air cooling efficiency is not high, IGBT damages easily caused by the excessive temperature rise, water cooling method has been proposed for the replacement the air cooling. Finite element software has applied to simulate and analyze the flow velocity distribution and temperature distribution of cold plate and the optimal design of high-power IGBT cooling water cooling system has implemented.9. High-temperature fan speed control system has actually been run stably in a cement plant in Yunnan, the annual saving of 1 million yuan per sets. |
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