Polypropylene Plant Uninterruptible Power Supply Study

At first, this paper introduces the principle and classification of UPS and toanalyze the selection principles of UPS, which belongs to the Olefin of polypropylenedevice and the maintenance status, which is about the new and old UPS. It putsforward the problems of old UPS and analyzes the features of the new UPS. It gives adetailed analysis of the six pulse、twelve pulse and twenty-four pulse rectifiercharacteristics, and elaborates the rectifier controlled strategy. Starting with thevoltage type inverter circuit, it will discuss about inverter features gradually in depth.It analyzes the advantages between unipolar PWM wave and bipolar PWM wave inharmonic side. It also analyzes inverter controlled strategy and gives the invertercontrolled method and a strict proof and designing.Besides, it analyzes the LC filter characteristics and makes a detailedintroduction of different parameters of the filter with different load when a unit stepresponses experiment. Aiming at the question, the LC filter parameters are constant,but the load changing will lead to a two order system characteristics significantly. Inorder to determine the filter parameters scientifically, it will derive the calculationformula of the parameters seriously, and then design a filter about the use of theformula. The lead-acid batteries, principles of nickel-cadmium batteries andcharacteristics are described. The two batteries of the features are contrasted. Thebattery brand and UPS are determined in the case of matching battery calculationmethod. The new UPS device with battery characteristics is introduced.It presents the AEG UPS’s structure、characteristics、technical parameters andfour kinds of operating mode, describing the main circuit, rectifier circuit and aninverter circuit diagram. It introduces the rectification control unit, inverter controlunit and the static bypass control unit and a main signal acquisition. It introduces theinverter unit IGBT trigger circuit, and analyzes the trigger circuit structure andapplication features. In this chapter, it also presents a new UPS A/D sampling、 themain program and SPWM wave generation software control flowchart.Then it makes simulation of the different rectifying circuit and analyzes therectifier output voltage harmonic content. It makes a simulation experiment when the rectifier failure closes suddenly. The battery can be put into work immediately. It willdetermine the charging and discharging circuit filter parameters. It will make an openloop control of UPS and find out that it cannot overcome disturbance shortcomings.It will also make a simulation experiment about the design of the inverter closed-loopcontrol scheme. The effect of disturbances is notable.Finally I will prospect the development direction of UPS and determine myown research direction in the future.