A resistor is connected in series between the neutral point of the power grid and the ground. Proper selection of the resistance value of the connected resistor can not only release the energy of the second half wave of single-phase grounding arc, thus reducing the possibility of arc re ignition, restraining the radiation value of grid overvoltage, but also improve the sensitivity of relay protection device to act on tripping, thus effectively protecting the normal operation of the system.
1. Highly targeted and well protected
The neutral grounding resistance cabinet is applicable to the situation where the neutral point of the system is grounded with small or medium resistance. At this time, when single-phase grounding fault occurs in the power grid, it is necessary to trip and cut off the fault line immediately. When single-phase grounding occurs in the power grid, the grounding resistance provides additional resistive current to the grounding point, making the grounding current resistive and capacitive, so as to ensure that the generated overvoltage does not exceed 2.6 times the phase voltage.
2. Compact structure, easy to install
The neutral point grounding resistance cabinet combines the scattered z-type grounding transformer (if the system has no neutral point leading out, it needs to be installed), resistor, current transformer, measuring instrument, grounding protection output terminal and other electrical equipment into a closed metal cabinet as a whole, and can be equipped with isolation switch, supplied in a complete set, with high safety and reliability, clear and neat layout, convenient for installation, commissioning, operation and maintenance.
3. Exquisite material selection to fully ensure product quality
The grounding transformer in the neutral point grounding resistance cabinet is a high-quality dry type transformer, and its primary winding is "z" shaped; the resistor is made of stainless steel alloy, nickel chromium alloy and other materials, with high conductivity, strong flow capacity, high temperature resistance, and the maximum use temperature of 1600 ℃; temperature coefficient ≤ -0.045%/℃, stable resistance, corrosion resistance, flame and explosion prevention, high reliability.
4. Complete monitoring functions and analog output
The neutral grounding resistance cabinet can be equipped with current transformer and intelligent controller, which can monitor the unbalanced current of neutral point under normal conditions; in case of single-phase grounding fault, the number of actions can be recorded; it can also provide analog output for the protection and monitoring system; special lightning arrester can also be installed as required. At the same time, the equipment can be equipped with measurement and control protection device according to user requirements.
There are four common neutral grounding methods in China's power system: direct grounding, non grounding, grounding via arc suppression coil (resonance grounding), and resistance grounding. The grounding operation mode of power system involves many important issues such as safe operation of power grid, reliability of power supply, and safety of users. In terms of professional technology, it involves power system, overvoltage and insulation coordination, relay protection, communication and automatic control, electromagnetic compatibility, grounding design and many other fields, which is a system problem with extensive contents. The neutral point grounding resistance cabinet is divided into transformer neutral point grounding resistance cabinet and generator neutral point grounding resistance cabinet from the protection object.
Xi'an Yudian Electrical Equipment Co., Ltd. is located in the second phase of the Science and Technology Enterprise Accelerator, Caotang Industrial Park, High-tech Zone, Xi'an City, Shaanxi Province. It is a high-tech enterprise integrating research and development, manufacturing, technical services and marketing of high and low voltage electrical products. Relying on the advantages of technology and talents in Xi'an, the company cooperates closely with well-known scientific research institutions and colleges such as Xi'an High Voltage Electric Apparatus Research Institute Co., Ltd., National Insulator Arrester Quality Supervision and Inspection Center, Xi'an Jiaotong University, etc. Advanced technology and complete testing equipment.
The company currently mainly produces 0.22~220kV voltage grade metal oxide arresters, overvoltage protectors, cable sheath protectors, pillar insulator arresters, counters, monitors, harmonic suppressors; surge protectors; transformer neutral point grounding protection devices , Transformer air-cooled control cabinet, terminal box, etc. The product has advanced design, sophisticated manufacturing, beautiful appearance, excellent performance and stable operation. The main products have passed the type test of the National Insulator Arrester Quality Supervision and Inspection Center.
The company always adheres to the business philosophy of "creating high-quality products with ingenuity and winning the trust of users with conscience", with the quality policy of "pragmatism, cooperation, innovation, refinement, quality in hand, and users in heart", "customer first, quality first". First, the development tenet of "Credit First", the unremitting pursuit of "continuously creating value for customers", and work together with new and old customers to create brilliance.
Contact Person：Li Kanghu
Contact Information：2903827762@qq.com