工业供电电源种类繁多,包括交流不间断电源、通讯电源、直流电源及各类高频开关电源。其中大功率直流电源在现代工业中具有十分重要的地位。目前我国的的直流电源大多数是采用单相桥式整流电路来获得,它具有电路结构简单、输出直流电压高但不可调等特点,然而直流电源能否在一定范围连续可调,直接影响了直流负载的正常工作,限制了其使用范围。该设计是针对桥式整流电路加以改进主要用晶闸管来代替普通二极管构成单相桥式半控整流电路,使输出直流电在0—198V之间连续可调。因为晶闸管除了具有单向导电的整流作用外,还可以作为可控开关使用且能用微小的功率去控制较大的功率。主要从主电路、触发电路、保护电路三个部分来设计,核心是通过触发电压去控制晶闸管的相位角来实现输出直流电连续可调。具有电路结构简单、工作稳定、成本低、实用性强的特点。
关键词:相控整流;触发;过流;过压
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Abstract
Currently, there are a variety of industrial power supplies, including Alternating Current Uninterrupted Power, communication power, Direct Current power and all kinds of high frequency switching power. Among them the high-power Direct Current power plays a very important role in modern industry, like the Direct Current power using in electrolysis, arc furnace, electroplating and so on. But whether the Direct Current power can be continuously adjusted directly affects the sphere of application and value of the Direct Current load. This design takes the advantage of power electronic technology to design an adjustable output Direct Current circuit, namely single-phase bridge type phased rectifier. It applies unijunction transistor trigger circuit and changes the charging and discharging time of capacitance by adjusting variable resistance in order to control the conduction angle of unidirectional thyristor to achieve adjustable Direct Current output. There are many kinds of phased rectifier circuit but this design is based on the single-phase bridge type phased rectifier. It has the advantages of simple circuit organization and high reliability, etc. For design, it mainly focuses on three circuits: the main circuit, the trigger circuit and the protecting circuit.
Key Words:Phase control rectifier; Trigger; Over current; Over tension
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