Design And Implimentation Of The HVDC Power Supply Used In The Power Supply System Of IDC Room

As the rapid development of information technology, the commercial Internet DataCenter has been built larger and larger, and it has more requirements on efficiency,environment friendly, and reliability than ever before. Meanwhile, as the essentialingredient of uninterruptible power system, the ordinary AC UPS has somedisadvantages, such as, low efficiency when operating, low redundancy and highchallenge in expansions. High voltage dc power supply (HVDC) system，however, canbetter meet these requirements while other issues are still good. HVDC system will beresearched in this dissertation.The dissertation first takes a analysis of structural features and operating principleof HVDC system, then the battery configuration, insulation monitoring technologies,three-phase PWM rectification technology used in power conversion unit are introducedwith an emphasis. The configuration and maintenance of the battery group is beenexplained based on a actual example. The balance bridge method and unbalance bridgemethod which is more sophisticated have been deduced, and there is a compare betweenthese two methods. These two methods are combined when use, so that the cost andefficiency can be trade off. The PWM rectifier is as the topology of AC/DC converterafter several familiar topologies have been compared. Aiming at three-phase andtwo-level voltage source PWM rectifier, a mathematical model is built in dq rotatingcoordinate system, and deduce the current feedforward decoupling control method.In order to output large current while voltage is still, and balance work efficiencyof HVDC and redundancy, the dissertation discusses parallel current sharing controlstrategy of the power conversion unit, and the master-slave method is adopted which isbased on communication. The cause and harm of zero sequence current is analysed.With the purpose of inhibiting the circulation, we import the current feedback controlelement in the DC side. For the sake of mathematical load sharing and communicationbetween grades, the load sharing control method is adopted which is based on CAN buscommunication. And then, we use Matlab software to conduct a simulation for a singlePWM rectifier and the rectifier parallel system, the accuracy of the rectifiermathematical model and the feasibility of current sharing control is verified.Then, the dissertation designs and determines the main circuit parameters of powerconversion unit and control system, introduce the design sequence of ISR, and build a5kW PWM rectifier prototype based on digital signal controller TMS320F28335. Someproblems such as the sequence of ISR, data saturation, optimization of drive circuit are discussed deeply, and given proper solutions. Finally, a experimental analysis andverification is taked on small power level, the results show that the PWM rectifier’sinput and output performance is good and suit for HVDC system usage in practice.