Research On Hv Frequency Drive Technology For Clinker Sintered Alumina

Nowadays, there are over 0.4 billion kilowatts motors accounting for 60 percent upon all power loads in China. The motor capacity chosen is larger than needed, hence, the power conservation potential of motor system is considerable. In many power plants in our country fans and pumps are driven by high-voltage motors and the flow is regulated respectively by baffles and valves. The motors always run at rating speed, as gives rise to additional power dissipations and high pressure on pipes. It is proved that approximate 20-30 percent power energy can be saved at the same loads if the fans or pumps are regulated by alternating current adjustable speed equipment instead of baffles or valves. In addition, some statistical documents show that there are about 10% motor faults caused by overlarge starting current and electromagnetic force. Alternating current adjustable speed techniques can improve motor's starting performance, therefore, motor's longevity can be prolonged and the product cost can be reduced.Based on the reasons mentioned above and the actual needs, the mathematical model of asynchronous motor under the condition of two phase quiescency and two phase rotating frame is gained, and then the mathematical mode of super dense-phase conveying load is founded. Combining the situation of the effect of pipe network resistance on machinery characteristic, the simplified model is gotton. The dynamic mathematical model deduced about motor driving blower is specificly achieved. The simulation result testifies that this simulation model is capable of reflecting practical physical model of motor, possessing upper reliability. Secondly, this paper analyzed the topological structure of high voltage frequency converter, connection mode and operation mechanism of transformer. Thirdly, we made emulation and calculation about harmonic content of voltage and current in line side and output side. The result indicates that multi commutation makes system reduce harmonic pollution in power network; that the circuit structure in unit series makes harmonic distortion little, motor damage small; with voltage modulation ratio debasing, output harmonic component is added; the whole modular design, maintenance convenience, simpleness. At last, this thesis describes the implementations of Sine Pulse Width Modulation (SPWM) and Space Vector Pulse Width Modulation (SVPWM) to achieve the purpose of variable-frequency adiusting-speed for induction motors.