Asynchronous Motor's Varying Frequency Speed Regulation And Energy-saving Control

Asynchronous motor is a mechanical-electric energy converter with high coupling and high nonlinear. Study on the nonlinear of asynchronous motor and their disposal method is the basic of realization of asynchronous motor's high efficiently operation. On taking into the nonlinear of asynchronous motor, the power matching principle provides a simple and effective method for asynchronous motor's energy-saving operation. This paper's study is meaning to economy and society especial on these days when the energy supply is tensing up while they are made poor use of and the society is calling for economization. Starting off the asynchronous motor's model taking into varying iron loss, and making the high efficiency operation as main theme, this paper studies the asynchronous motor's nonlinear model, power matching principle, high-efficiency motor drive system, PWM's technique and the maximum efficiency experiment, and etc. Asynchronous motor's model is the basic for simulation and analysis. Through the flux and current curve fitting, the same dealing with the d and q axis flux circuit, the motor's flux saturation is conquered. And by adding a branch circuit for iron loss equivalence resistance, the varying iron loss is taken into motor's model. These offer the more exact model base for motor's high-efficiency study. There exist two power systems in motor-active power and reactive power; their magnitude should be accommodated with the motor ration and the motor's load. Active power and reactive power's reasonable matching can result in motor performance in the optimal state, this is so-called Active power and reactive power's reasonable matching principle. On the case of varying frequency and motor model taking into iron loss, the power reasonable matching maximum efficiency control is draw. And the ratio of active power to reactive power is deduced and application scope is made clear. The asynchronous motor's energy-saving control is study focus on the field of electrical application. In this paper, some usual efficiency optimization classed into two basic optimization class-one based on motor model, the other on online searching method, are analyzed and compared for each other. Thus the power matching maximum efficiency scalar control is proposed, which are proved that it is sample and effect method for efficiency global optimization. On the realization of PWM for drive system, some common PWM are focused. It is proved that SVPWM is suit for the power matching maximum efficiency vector control, while the 12216 form PWM based on 30 pulses per circle PWM is fit for the power matching maximum efficiency scalar control. A variable voltage variable frequency drive system based DSP microprocessor and IPM power converter module is built up. And two experiments are carried out to verify the motor maximum efficiency control's characteristics, one is on the condition of constant speed and constant torque load and variable input frequency, the other is on the condition of constant torque load and variable input frequency speed regulation. Lastly on the base of conventional vector control of asynchronous motor, the power matching maximum efficiency vector control with flux observer and torque observer is carried out.