SVG dust and moisture problem overview
1.Severity of dust accumulation
Many early new energy power plants, such as wind farms and photovoltaic power plants, were equipped with air-cooled SVG. This device can quickly and continuously provide capacitive and inductive reactive power, achieve proper voltage and reactive power control, and ensure stable, efficient and high-quality operation of the power system.
SVG is installed indoors or in a container (hereinafter referred to as the SVG room) and continues to heat up during operation, so the air will continue to circulate inside and outside the SVG cabinet. After a period of operation, a large amount of dust will accumulate on the SVG internal device. After cleaning, it will accumulate a lot again for a period of time.
2.Moisture in SVG
In rainy and snowy weather, moisture enters the SVG chamber or container with the cooling air and mixes with the dust accumulated on the circuit board or power module to form mud, causing:
- Reduced electrical gaps and distances.
- Decrease insulation performance.
3.Consequences of dust accumulation and moisture mixing
- The accumulation of dust causes the cooling efficiency to decrease, and the heat continues to accumulate, resulting in failure or even burning.
- Sludge damages electrical performance, causing SVG power unit failures, such as discharging, tripping, or even firing guns.
- Control unit failure: dust accumulation, poor circuit board heat dissipation, and dust will generate static electricity, causing control unit failure.
- Maintenance difficulties: To clean internal dust, the internal device needs to be disassembled to clean the dust. The workload is large and the efficiency is low, which affects production and equipment safety.
SVG Dustproof and Moisture Removal Solution
1. Key issues to be solved
To solve the problems caused by air-cooled SVG dust and moisture, the corresponding solutions need to be solved:
- Ventilation and heat dissipation are guaranteed, and at the same time must be kept clean and dustproof.
- Remove moisture to solve the effects of moisture.
- Low retrofitting and operating costs.
- Convenient operation and maintenance.
2. Reasons for dust to enter
The dustproof level of the SVG Equipment Container air inlet is low. Currently, the dustproof level is ≤ IP5X, which is the main reason for dust to enter.
IP5X dustproof level, not suitable for forced air cooling for air cooling and dust protection;
Dustproof that forces air convection to dissipate heat requires the SVG container’s air inlet dustproof level to reach IP6X.
IP5X and IP6X dustproof standard definitions:
According to standards: GB/T4208-2017/IEC 60529:2013 shell protection level (IP code)
Protection grade IP5X: When the inner pressure of the shell is the same as the surrounding atmospheric pressure, no dust enters, referred to as static dustproof for short, the cabinet. When there is no air circulation outside, it is dustproof, but when there is an internal and external pressure difference and the air is convection inside and outside, it cannot be dustproof.
Protection grade IP6X: The equipment works normally, and the air pressure inside the cycle shell is lower than the surrounding atmospheric pressure, such as due to the thermal cycle effect. When the pressure difference is ≤ 2 kPa, no dust should enter, referred to as dynamic dustproof or dust-tight for short. This test standard requires that when there is forced air circulation inside and outside the cabinet, the airflow of the dustproof SVG can reach tens of thousands of cubic meters per hour, and the wind pressure is very high. According to the standard, an IP6X protection grade ventilation and dust filter device (wind pressure resistant to 2 Kpa) should be used.
3.SVG dustproof and moisture-proof solution
- Raise the dustproof level of the SVG inlet window to the IP6X dustproof level.
- SVG is equipped with an IP65 dustproof filter fan and window window, and the waterproof level is upgraded to IPX5.
- The SVG box is equipped with a heater for outdoor applications and placed on the outside. In this way, when the humidity is high in rain or snow, the air is heated and dehumidified before the wind enters the SVG room or container.
- Automatic control: automatically start and stop the filter fan to ventilate and dissipate heat; automatically control the heater to dehumidify and prevent moisture.
