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There are problems with the variable frequency power supply. The requirements for the environment of the variable frequency power supply are the same as those of other electrical equipment, such as medium voltage switchgear, transformer, etc.: the altitude is below 1000m, the relative humidity is less than 95% or 90%, there is no condensation, and the ambient temperature is less than 40e. When the altitude exceeds 1000m or the ambient temperature is higher than 40e, the variable frequency power supply must be derated for use. The ambient gas is non corrosive, non dust, non fire and explosive gas. The cooling mode of variable frequency power supply is water cooling and forced air cooling; The standard protection level of the inverter cabinet is IP20 or IP21, which can be increased to IP42 or IP54 when users have special requirements Based on the above simple environmental requirements of variable frequency power supply, both engineering design units and users will treat it as a general medium voltage switchgear or transformer for indoor layout and installation, and usually place the variable frequency power supply and other electrical equipment in the same room. If the conditions are good, the variable frequency power supply room will be designed separately as the transformer room. It is generally believed that the variable frequency power supply manufacturer has fully considered the ventilation and cooling factors of the variable frequency power supply. Therefore, in general, only simple measures such as increasing the indoor headroom or installing axial flow fans on the external wall are taken in the installation. From the electrical point of view, there is no doubt that the installation and layout of variable frequency power supply is similar to that of medium voltage switchgear or transformer. However, from the power loss of the three, there is no small difference between them. Remark loss of product variable frequency power supply oil immersed transformer dry-type transformer high voltage switch cabinet (%) 25223 Neglected variable frequency power supply loss refers to that within the entire speed regulation range, all three are rate products, and the loss only accounts for a small part of its total power. The loss of variable-frequency power supply at rated frequency and rated power is 2%, but there are few variable-frequency power supplies that often operate at rated points. Their loss is about 4% within the normal operation range of 70% 85% speed Take the 1000kVA variable frequency power supply commonly used in the water industry as an example, the corresponding loss during the regular speed regulation operation is 40kW, and all of these losses are converted into heat. The heat dissipation of oil immersed transformer is to transfer the heat to the radiator of the transformer shell through the circulation of insulating oil, and then the heat is taken away by the flowing air. Therefore, its heat dissipation mode is much better than the air cooled variable frequency power supply; Although the dry-type transformer can be forced ventilation and heat dissipation like the variable frequency power supply, the heating time constant of the transformer can be as long as several hours, while the heating time constant of the variable frequency power supply is only a few minutes due to the characteristics of the rectifier and inverter semiconductor devices, and their overtemperature resistance is incomparable. It can be seen that the installation and layout of variable frequency power supply cannot be treated as conventional medium voltage electrical equipment, and the temperature of indoor cooling air must be fully considered. The manufacturers of variable frequency power supply usually install centrifugal fans in the cabinet or axial flow fans on the top of the cabinet to conduct forced air cooling for the power device groups of the rectifier and inverter, and put forward the aforementioned environmental requirements, but they did not put forward suggestions on how to ensure these requirements. At this time, if there is no perfect air exchange system in the indoor and outdoor space, most of the heat emitted by the variable frequency power supply will stay indoors, making the ambient temperature of the variable frequency power supply rise continuously, and the environmental conditions required for air cooling will be completely changed.
變頻電源，存在問題變頻電源對環境的要求與其他電氣設備如中壓開關柜、變壓器等一樣：海拔1000m以下、相對濕度小于95%或90%、無凝露，環境溫度要求低于40e。當海拔超過1000m或環境溫度高于40e時，變頻電源必須降容使用。環境氣體為無腐蝕性、無塵埃、無引發火災及爆炸性的氣體。變頻電源的冷卻方式為水冷卻和強迫空氣冷卻;變頻電源柜體的標準防護等級為IP20或IP21，在用戶有特殊要求時可提高至IP42或IP54.
基于變頻電源的上述簡單的環境要求，無論是工程設計單位或用戶都會把它當成一般的中壓開關柜或變壓器來進行室內布置安裝，通常將變頻電源與其他電氣設備同置一室。條件較好的會像設計變壓器室一樣單獨設計變頻電源室。大家普遍認為變頻電源生產廠家已經充分考慮了變頻電源的通風和冷卻因素，因此，一般在安裝上只采取提高室內凈空高度或在外墻上安裝軸流風機等簡單措施。 航空地面電源，36V航空電源，400HZ變頻電源，115/200V電源，27V直流電源，400HZ電源，航空電源
從電氣角度來看，對變頻電源采用與中壓開關柜或變壓器相似的安裝布置方式無可非議。但如果從三者的功率損耗來看，它們之間有著不小的差別。產品變頻電源油浸變壓器干式變壓器高壓開關柜備注損耗(%)25223忽略不計變頻電源損耗指在整個調速范圍內，三者都屬于率產品，損耗僅占其總功率的很小一部分。變頻電源在額定頻率和額定功率時的損耗為2%，但幾乎沒有經常在額定點運行的變頻電源。它們在70%85%轉速常規運行范圍內的損耗約4%.以自來水行業常用的1000kVA變頻電源為例，其常規調速運行時相應的損耗達40kW，這些損耗全部轉化為熱量。 油浸變壓器的散熱是通過絕緣油的循環將熱量傳遞到變壓器外殼的散熱片上，再由流動空氣帶走熱量，因此它的散熱方式比空氣冷卻型變頻電源好得多;干式變壓器雖說與變頻電源一樣可以是強迫通風散熱的，但變壓器的發熱時間常數長達數小時，而變頻電源由于整流和逆變半導體器件的特性決定其發熱時間常數只有幾分鐘，兩者的耐超溫能力是無法比擬的。
由此可見，變頻電源的安裝布置方式不能按常規的中壓電氣設備來對待，而必須充分考慮其室內冷卻空氣的溫度。變頻電源生產廠商通常在柜內安裝離心式風機或柜頂安裝軸流式風機，對整流器和逆變器的功率器件組進行強迫空氣冷卻，并提出了前述的環境要求，但他們沒有對如何保證這些要求提出建議。此時若室內外空間無完善的空氣交換系統，則變頻電源散發出來的熱量絕大部分滯留于室內，使變頻電源的環境溫度不斷上升，空氣冷卻所需的環境條件就完全改變了。
