Harmonic characteristics of power distribution system in port and wharf industry

In order to meet the needs of large and medium-sized ships and global economic integration, as well as the constraints of economic and social development on resources and the environment and the development of ecological civilization in coastal ports, the development and design of deep water routes and parking spaces, and the design of port transportation machinery Large-scale and high-efficiency, information and control integration in port management, systematic development based on the characteristics of different types of goods, large-scale, intelligent and ecological systems are the key aspects of future port reform and innovation.

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Due to the needs of distribution, there are a large number of aviation crane loads in the loading industry such as ports, and inverters are installed on many loads. A large number of frequency converters greatly increases the harmonic content in the power distribution system of the port industry. At present, the rectification process of most inverters uses six-pulse rectification to convert AC power into DC power, so the harmonics generated are mainly the fifth, seventh, and eleventh harmonics. The harm of harmonics in petrochemical system software is specifically manifested in the harm to power engineering and the error of accurate measurement. Studies have shown that harmonic currents will cause additional loss in the transformer, which will cause overheating, accelerate the aging of the insulating medium, and cause insulation damage. The existence of harmonics increases the apparent power and has a great negative impact on the efficiency of the transformer. In addition, the pulse current has a direct negative impact on the capacitors, disconnectors and relay protection equipment in the power supply system. For many testing instruments, the real root mean square value cannot be measured, but the average value can be measured, and then the imaginary waveform is multiplied by the positive index to obtain the reading value. When the harmonics are serious, such readings will have large deviations, resulting in measurement deviations.

Problems you may encounter?
1. Starting problems of various aviation cranes and pumps
2. The frequency converter produces a large number of harmonics, which affects the safe operation of the electrical equipment of the system
3. Reactive power penalty caused by low power factor (according to the power factor water and electricity fee adjustment method formulated by the Ministry of Water Resources and Electric Power of our company and the Price Bureau of our company);

Our solution:
1. Install HD high-voltage reactive power automatic compensation equipment on the 6kV, 10kV or 35kV side of the system to compensate the reactive power of the system, improve the power factor, design the effective reactance rate, and partially automatically control the pulse current of the system;
2. The high-voltage side of the system uses a power quality dynamic recovery system to dynamically compensate reactive loads in real time and maintain the reliability of the power quality of the system;
3. The active filter Hongyan APF automatic control system pulse current is installed on the bottom voltage 0.4kV side, and the static data security compensation equipment Hongyan TSF compensation system software reactive load is selected to improve the power factor.


Post time: Apr-13-2023