在中频设备维修时经常可以发现在维修时花费了大量的精力和时间，往往最后的原因很简单。如：连线虚接、螺钉未紧固、断水、某器件烧坏等。为了缩短维修时间，就需要我们在维修时不断的总结经验，勤于观察，同时也要掌握一些维修技巧。和医生给病人看病一样，在中频电源维修时需要望、闻、问、切后判断故障所在的位置。

In the intermediate frequency equipment maintenance can often be found in the maintenance cost a lot of time and energy, often the last reason is very simple. Such as: virtual attachment, screw fastening and water, such as a device to burn out. In order to shorten the maintenance time, we need to constantly sum up experience in maintenance, and observation, but also to grasp some maintenance techniques. And doctors give patients, in medium frequency power supply when maintenance after need to inspection, auscultation and olfaction, inquiry, and pulse-taking and palpation determine fault location. < / p >

　　望：所谓望就是观察设备在运行时其仪表的参数、设备内有无发热、发红、螺钉松动等外观现象，这里主要介绍有关仪表参数和设备运行状态的关系。在中频电源运行时中频电压、直流电压、直流电流三个仪表之间有着密切的联系，通过观察这三个仪表的参数即可判断出中频电源是否运行正常。我们知道，直流电压和直流电流的乘积是中频功率，直流电压和直流电流的比值可以反映出负载的阻抗匹配状态。如：250kw的中频设备，直流电压的最高平均值是513V，直流电流的最高平均值是500A，如果设备在运行时直流电压达到500V，而直流电流值为500A，那么其阻抗达到了最佳匹配值。若直流电流小于500A，其阻抗值偏高，若直流电流大于500A，则阻抗值偏低。这就是说：可以通过观察直流电流和直流电压的值看出负载阻抗的匹配状况。

< p > look: the so-called hope is to observe the equipment within the parameters of the instrument and equipment at run time whether appearance phenomena such as fever, redness, screw loosening, related to instrument parameters and equipment running status are reviewed. In medium frequency power supply runtime intermediate frequency voltage, dc voltage, dc current three instrument has a close connection between, by observing the three parameters of instrument can judge the medium frequency power supply is operating normally. We know that the dc voltage and dc current is the product of intermediate frequency power, the ratio of dc voltage and dc current can reflect the state of load impedance matching. Such as: 250 kw intermediate frequency equipment, the highest average dc voltage is 513 v, the highest average dc current is 500 a, if the device at runtime dc voltage of 500 v, and for the 500 a dc current value, then the impedance value has reached the best match. If it is less than 500 a dc current, impedance values on the high side, if more than 500 a dc current, low impedance values. It means that the value of the dc current and dc voltage can be observed that load impedance matching conditions. < / p >

　　直流电压和中频电压的比例可反映出逆变器的工作状态，例如：直流电压为510V，中频电压为700V，逆变的引前角就为36°。我们用700V／510V=1.37来看，一般，中频电压和直流电压的比例在1.2～1.5之间我们均认为逆变器工作正常。如果比例小于1.2，则引前角太小，逆变器很难换相；如果大于1.5倍，则引前角太大，有可能设备就会出现故障。 < p > dc voltage and the proportion of intermediate frequency voltage can reflect the working state of the inverter, for example: dc voltage is 510 v, intermediate frequency voltage is 700 v, inverter of anterior horn for 36 & deg; . We use 700 v / 510 v = 1.37, in general, the proportion of intermediate frequency voltage and dc voltage between 1.2 ~ 1.5 we all think that inverter is working properly. If the ratio is less than 1.2, the rake Angle is too small, inverter is very difficult to commutation; If it is greater than 1.5 times the anterior horn is too big, possible equipment failure will occur.