ITER极向场变流器温升试验方法

ITER极向场变流器是一种高功率大电流的六脉波桥变流器，其额定容量41 MV·A、额定电流27.5 kA。为了承载如此大的额定电流，ITER极向场变流器被设计成每个桥臂由12个晶闸管支路并联组成。在温升试验中，晶闸管支路中的晶闸管壳、快熔、软连接以及RC回路电阻等多个关键部位的温度需要检测，如果每个晶闸管支路都布置测温点，则测温点多达几百个，大大增加其温升试验的难度。为简化测温点、便于温升试验，本文采用先均流再温升的试验方法，通过均流试验得出各桥臂均流系数，在均流系数最小的三个桥臂中选出承担最大电流的晶闸管支路，然后在温升试验中只需验证这三个承担最大电流晶闸管支路的温升。由焦耳定律可知，只要承载最大电流的三个晶闸管支路关键位置的温升满足要求，则其他晶闸管支路的温升一定满足要求。该试验方法将测温点由几百个简化成十几个，为测温点的布置以及温度数据的采集带来便利。

Temperature rise test method of ITER poloidal field converter

International thermonuclear experimental reactor (ITER) poloidal field (PF) converter is a high-power and heavy-current six-pulse converter bridge with rated capacity of 41 MV·A and rated current of 27.5 kA. For such a large rated current, ITER PF converter is designed to consist of 12 thyristor branches in parallel on each bridge arm. In temperature rise test, the temperature of several key parts such as thyristor case, fast fuse, flexible connection and RC loop resistance in the thyristor branch needs to be detected. If the temperature measurement points are arranged in each thyristor branch, there will be hundreds of temperature measurement points, which greatly increases the difficulty of temperature rise test. In order to decrease the temperature measurement points and facilitate the temperature rise test, the test method that the current balance test is performed first to get three thyristor branches with maximum current sharing and then the temperature rise test is performed at that key parts on these three thyristor branches is proposed in this paper. According to Joule's law, the key parts temperature rise of other thyristor branches must satisfy the requirement as long as the temperature rise of that key parts in these three thyristor branches with maximum current sharing satisfies the requirement. This test method simplifies the temperature measurement points from hundreds to dozens, which facilitates the layout of temperature measurement points and the acquisition of temperature data.