1、 Project Overview

　　Hami Power PlantThe 4 × 660MW project, as one of the supporting power sources for the ± 800 kV high-voltage direct current transmission and distribution project from Hami to Zhengzhou, is located adjacent to the No.1 mine in the Dananhu mining area of Hami, which belongs to State Grid Energy Hami Coal and Electricity Co., Ltd. The project adopts the construction model of a coal electricity integrated pithead power plant. Coal is directly transported into the plant by a belt conveyor, which can achieve on-site conversion of resources and transform coal transmission into power transmission, in line with national energy industry policies. At the same time, the construction of this project can connect Xinjiang, which accounts for one sixth of the total area of the country, to the Northwest Power Grid, thereby achieving a truly national power grid and optimizing resource allocation on a larger scale. It also conforms to the overall energy flow trend of "West East Electricity Transmission, North Coal South Transportation, and North South Electricity Transmission" in China.

2、 Overview of working conditions

Hami Power PlantThe direct air cooling system for the 3 # and 4 # units of the 4 × 660MW project consists of 8 columns of direct air-cooled condenser systems (ACC), each with 8 fan units (1 fan unit per fan unit), totaling 64 fan units. Each fan unit is controlled by a frequency converter to adjust the fan speed and maintain the turbine exhaust pressure at the set value. As a typical nonlinear load, frequency converters generate high-order harmonic currents during operation, causing harmonic voltage and current in the power supply system to exceed the standard, resulting in poor power quality and seriously affecting system reliability and stability.

To improve the efficiency of the factory power supply, reduce the non application capacity of the power supply, and effectively eliminate the long-term harmonic pollution generated by the frequency converter, Sifei is selectedThe SFRPF series active power filter filters out harmonic voltages and currents generated during the operation of the frequency converter.

IIIIntroduction to the functions of SFERE series active power filters

Active power filter is a new type of power electronic device used for dynamically filtering out harmonics and compensating reactive power. It can filter out and compensate for harmonics (with changes in size and frequency) and dynamic reactive power in real time, overcoming the shortcomings of traditional harmonic suppression and reactive power compensation methods such as traditional filters, and achieving system harmonic filtering and reactive power compensation functions. It is widely used in power, metallurgy, petroleum, port, chemical, and industrial and mining enterprises.

1. Real time display

Real time measured data: voltage, current, total harmonic voltage distortion rate of power supply and load（THDU）、 Total harmonic current distortion (THDI), various harmonics (THIn), power, power factor, waveform of each phase, harmonic bar graph, switch status, etc.

2. Event record

Can query the various operation records of the filter by the operator, such as startup, shutdown, parameter setting, etc; It can display alarm information in real-time and provide historical alarm record queries,500 loop displays, providing a regular fault assistance menu for maintenance personnel to quickly diagnose faults.

3. Performance indicators

　　Filter frequency selection: 2-50 times optional; Full response time: less than 5ms; target power factor: adjustable from -1 to 1; Switching frequency: 20kHz; Noise index:<65DB; overall efficiency: greater than 97%.

4、 Project Summary

The expected goals have been achieved, and the harmonic voltage and harmonic current distortion rates at the incoming cabinets of each transformer have reached the national standard《The requirements of GB/T 14549 have purified the electrical environment, ensured the safe and stable operation of equipment, and greatly improved the effective utilization rate of electrical energy; Reduced distribution line losses, increased terminal voltage, and extended the service life of cables and equipment.