Load Analysis

For DC-powered equipment, a rectifier is used in the process of converting AC to DC, and the rectifier device generates a large number of harmonics injected into the grid during operation. When using 6-pulse rectification, the 5th and 7th harmonics are generated in the system, so polysilicon ingot furnaces use rectifier equipment, which generates a large number of harmonics during operation.

Harmonic characteristics

The main load in the polysilicon production power supply system is rectifier reduction furnace (12 pulses), hydrogen production equipment (12 pulses), thyristor temperature control equipment (6 pulses), UPS (6 pulses), etc., which makes a large number of harmonic currents in the power supply system, and the harmonic currents are mainly 5, 7, 11, 13 times;

The presence of a large number of harmonics seriously interferes with the safe operation of other loads, measurement errors, affects the service life of equipment, etc., so that the loss of transformers and transmission lines increases, so that the reactive power loss of the system increases, and the power factor decreases.

Harmonic hazard

• Voltage: high voltage distortion rate, overvoltage phenomenon;
• Harmonics: protection failure, transformer and cable heating and aging, insulation reduction, inaccurate measurement, increased energy consumption, poor communication;
• Reactive power: low power factor, large line loss.

Solution

Using active power filter BW-APF, APF has the characteristics of fast response, filtering out 2-51 harmonics, filtering out the harmonic current generated in the system, stabilizing the voltage, purifying the power grid, eliminating the tripping phenomenon caused by harmonics, eliminating the high harmonics and even harmonics in the system, reducing the heat generation and aging caused by harmonics, reducing the measurement error, and reducing the impact on communication.