By hvhipot 
In industrial and mining enterprises, DC resistance testers have large inductive loads, such as electric arc furnaces, DC motor speed control systems, rectifier frequency conversion equipment, and the active power they consume, but they also account for a large amount of inductive reactive power, power factor, The power of electrical equipment drops. As the reactive power capacity of a device virtual account, the Hertz power DC resistance tester increases the line current, which is proportional to the line loss and the square of the current, which is a great waste of power reseries resonances.
In addition, inductive loads will produce a lot of work, causing high-order harmonics of power, high-order harmonic pollution to the power grid, deterioration of power quality, and abnormal operation of electrical instruments. In order to improve the power factor, harmonic control and dynamic filtering can compensate the series connection of capacitors and inductors, forming an offset circuit, and exerting the effects of reactive power compensation and harmonic filtering. Compensation systems for various filters, basic power capacitors, ferrite core choke coils, reactive power compensation controllers and power switch equipment, etc., are connected to the grid, shut down tasks, and power switch equipment, which are the overall important compensation system . One of the components. Now, the equipment of the power switch is as follows.
1. General contact
The DC resistance measuring instrument has the advantages of very small contact resistance and suitable for large current input, but its shortcomings are also obvious. Pulling the liberation for a long time is not suitable for the situation of a fast and comfortable life. The contacts of the contactor are prone to sparks, and the surrounding electronic equipment may not operate normally due to the damage that the contact rod cannot break and the interference of large forces.
2. Pre-made special contactor resistance
This kind of contact is larger as a whole. In fact, there is no surge current that really solves the problem during work, and there is no ideal contact and thermal damage tolerance phenomenon, which sometimes occurs, so it will be unsatisfactory with this type of exposure. Switchgear contacts.
3. The solid state relay is triggered by zero crossing
The internal thyristor of the AC relay is always configured as two anti-parallel unidirectional thyristors or bidirectional thyristors. When receiving the switching signal of the solid state relay, it waits for the two ends of the pressure to approach zero voltage once and the switch is turned off, and then act to cut off the solid state relay It can be seen from the received signal that although the solid state relay is cut off in a very good working condition, it has fatal flaws. In the work of the oil withstand voltage measuring instrument and high-order harmonic noise, its force is limited, which further promotes the switching area .
4. Discrete composite switch
The DC resistance tester combines the advantages of traditional electromagnetic relays and non-contact switches. The time can delay the circuit’s resistance and capacitor to complete the relationship between their functions. However, due to discrete components, dispersion and reliability parameters will affect the long-term normal operation of the entire complex switch.
The above-mentioned shortcomings of the existing switching equipment, the high-performance embedded system, as the control unit of the core switching equipment, has the advantages of fast calculation speed, short response time, stability by small surge current and many other advantages, and has a wide range of application prospects.