1. Air conditioning cooling

In order to improve the application stability of high-voltage and high-power inverter, solve the problem of environmental heat dissipation of high-voltage inverter. At present, commonly used method is closed air conditioning cooling. This method is mainly to provide a fixed room with thermal insulation effect for the high voltage inverter and calculate the cooling capacity of the air conditioner according to the heating capacity of the high voltage inverter and the room area, so as to equip a certain number of air conditioners. When air conditioning is used for cooling, the building area of the room will increase the cooling load of air conditioning. At the same time, due to the converter exhaust hot air can not be all air conditioning inhalation cooling, therefore, resulting in the system operation efficiency is low, resulting in the secondary waste of energy saving.

The inverter inhales air from the front and back of the cabinet, and carries the heat inside the inverter into the room through the cabinet head blower.Thus, a cyclone vortex zone with high temperature and pressure is formed in the upper part of the converter chamber, and a partial negative pressure zone is formed in the front part of the converter.In operation, the upper part of the front of the inverter power cabinet is actually cooling by breathing in the hot air that has just been discharged.The air conditioner usually adopts the structure of down-in and up-out air, which forms the phenomenon of "scrambling for wind" with the frequency converter to some extent, which is the "mixed circulation zone".In this area, the air inhaled by the inverter is not completely the cold air after the cooling of the air conditioner, and the cooling treatment of the air conditioner has not cooled all the hot air discharged by the inverter, which leads to the low operating efficiency of the whole cooling system.Inverter itself is energy-saving equipment, and the commonly used air-conditioning type cooling will cause secondary waste of energy.This situation is more obvious in high power and superpower frequency conversion application system.

2. Air duct cooling

Air duct design of power cabinet is shown in the following figure:

From power cabinet cooling system diagram shows: power unit internal cooling system by installing in a forced cooling fan in the unit cell of the radiator, satisfies each power unit cooling demand, at the same time, because of the power unit inside the fan blow hot air, make it into the wind formed strong negative pressure within the cabinet put oneself in another's position, the tank outside cold wind into the high voltage variable frequency air in great quantities, the unit by power unit duct radiator for cooling.At the same time, due to the large amount of ventilation of the cabinet headwind machine, a strong negative pressure is formed in the closed air chamber, and the hot air in the accelerated power unit enters the closed air chamber and draws out the high voltage inverter outside the cabinet through the cabinet headwind machine.Through the establishment of a tight and smooth air duct, and the design of forced-air cooling in the power unit, greatly improve the heat dissipation ability and efficiency of the high voltage inverter cooling system, at the same time, also can reduce the radiator volume and power cabinet volume, realize the miniaturization of high voltage inverter, for the user installation of high voltage inverter to save space.

3. Air-water cooling system

The operating environment temperature of high-voltage inverter is usually required to be -5 ~ 40℃, and the dust content of the environment is lower than 950ppm.Excessive temperature will cause overheat protection and tripping of frequency converter, and excessive dust content will lead to excessive maintenance of frequency converter ventilation filter replacement and cleaning, increasing maintenance costs.Therefore, the cooling method and system structure are very important.

In order to solve the problem of cooling and controlling the operating environment of high voltage inverter, improve the safety and reliability of the system and reduce the operating cost. It can solve the problem of high heat dissipation density, large power, effectively improve system security and reliability, and reduce the operating cost.

The air-water cooling system is a kind of cooling system with high efficiency, environmental protection and energy saving.It is widely used in high voltage and high power frequency conversion applications in electric power, steel and other industries.Because the system adopts a complete mechanical structure design, it has obvious safety and reliability compared with the electrical and electronic equipment such as air conditioners.

The main principle is: the hot air of the frequency converter is directly through the air duct through the air cooling device for heat exchange, the cooling water is directly carried away the heat lost by the frequency converter; The cooling air is discharged into the room. The cold water temperature in the air cooling device is lower than 33℃, which means that the ambient temperature in the inverter room can be controlled below 40℃ to meet the requirements of the inverter for environmental operation after the hot wind passes through the heat sink. Thus, the good operating environment of the inverter room is guaranteed. The cooling water is completely separated from the circulating air, and the water pipeline is clearly separated from the high-pressure equipment outside the frequency conversion room, so as to ensure that the high-pressure equipment room will not be threatened by waterproofing, insulation damage and other safety threats and accidents.

At the same time, because the room is closed, the inverter USES the circulating air in the room to cool the equipment, which has the characteristics of low dust degrees and small maintenance. The adverse influence of the environment on the operation stability of the inverter power cabinet and control cabinet is reduced. The structure schematic diagram of the air-water cooling system is as follows: