Gaoyun electric filter capacitor difference

Ningbo Gaoyun Electric Co., Ltd. is located in Ningbo, a modern port city of China. It is a member of China Electrical Industry Association, specializing in the production of 0.25-2kv medium and low voltage metallized power capacitors. The company has more than 70 employees, 12 professional and technical personnel, more than 30 sets of advanced production power capacitor equipment for filter capacitors, and 3800000 kvar self-healing power capacitors for cylindrical capacitors. Gaoyun company, which grew up with the power capacitor Committee of China electronic technology society, has gone through 20 years of ups and downs. Intelligent capacitors have formed a complete set of scientific management system through entrepreneurship and hard work.

In the distribution network, the wave form of filter capacitor should be normal sine wave. However, with the development of modern production and electronic technology, a large number of rectifier and converter devices are used in industrial and mining enterprises, electric arc furnace, rolling mill and frequency converter are widely used in metallurgical machinery industry, rectifier, carbide furnace and welding equipment are widely used in chemical industry, and machine pump frequency conversion and speed regulation devices are widely used in petrochemical industry The three-phase bridge controlled rectifier injects a large number of 5th harmonic; in the transportation of electric locomotives, trams, subways, rail transit, a large number of rectifier devices are used, these electrical equipment are non-linear loads, and their voltage and current will have different degrees of distortion. The distorted waveforms contain high-order harmonics, including the high-order harmonics of small capacity caused by rectification and frequency conversion of household appliances. The harmonic current generated by these high-order harmonics enters the distribution network, which seriously affects the safe operation of the power grid and pollutes the power quality.

The harmonic sources in Shunyi area of Beijing mainly include: traction station along Daqin electrified railway, rolling mill and vacuum sintering furnace equipment of metallurgical cold rolling production line, furnace equipment in semiconductor production process, especially Mulin traction station of Daqin Railway, the harmonic and negative sequence (fundamental wave) injected into the power grid affect the voltage quality and safe operation of the regional power grid. With the development of airport logistics and airport economy in Shunyi District, the quality of voltage is an important part of high-quality service in power supply enterprises, so it is very important to eliminate harmonic pollution.

1. Direct harm of higher harmonic to electrical equipment

The voltage distortion of the AC power grid will cause the trigger pulse interval of the control angle of the conventional converter to be unequal, and amplify the voltage distortion of the system through the positive feedback, so that the rectifier can not work stably; while the inverter may fail to work normally due to continuous commutation failure, or even damage the commutation equipment.

When the neutral point of the winding is grounded, the distributed capacitance in the grid is large, or the shunt capacitor with the neutral point grounded is installed, the third harmonic oscillation will be formed, which greatly increases the additional loss of the transformer. For the triangle connected transformer, it will form circulation in the winding, which will overheat the winding, and the harmonic current will greatly increase the copper loss and iron loss of the transformer.

The skin effect and magnetic potential eddy current produced by high-order harmonic current in the motor will increase the additional loss in the motor core and winding with the increase of frequency, which will easily cause pulsation when the motor starts, and the interference torque will make the motor produce greater noise. Due to the large load of the motor, the additional loss caused by high-order harmonic has a significant impact on the power load.

The measuring instruments are designed under the ideal condition of 50Hz standard sine wave. When the power supply voltage or current contains high-order harmonic components, it will affect the accuracy of the instrument measurement and the normal operation of the induction watt hour meter.

The high-frequency harmonic current in the power line flows through the magnetic field coupling. In the adjacent communication lines, there will be interference. Under the joint action of harmonic and fundamental wave, the telephone ring will be triggered by mistake, which will interfere with the normal operation of the communication line system and affect the communication line. Under certain conditions, it will also threaten the safety of communication equipment and personnel.

Higher harmonic will seriously affect the relay protection and automatic device of power system, cause all kinds of protection misoperation, and threaten the safe operation of power system.

The high-order harmonic will cause resonance overvoltage and damage the ballast and capacitor for the lighting of the ballast with start-up and the capacitor with improved power factor. The higher harmonic will distort the picture of TV and computer, and the picture brightness will fluctuate. Overheat the components in the machine and make the computer data wrong.

The high-order harmonic can increase the dielectric loss, heat generation and shorten the service life of the capacitor. After absorbing the harmonic, it will cause the over-current of the capacitor and fuse the fuse. When the capacitor and the network inductance form a series resonance, the harmonic will be amplified and the capacitor will be burnt. The voltage distortion of the AC power grid will cause the trigger pulse interval of the control angle of the conventional converter to be unequal, and the voltage distortion of the positive feedback amplification system will make the operation of the rectifier unstable; while the inverter may fail to work normally due to continuous commutation failure, or even damage the commutation equipment.

The filter capacitor is really good.