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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.
变频电源，存在问题变频电源对环境的要求与其他电气设备如中压开关柜、变压器等一样：海拔1000m以下、相对湿度小于95%或90%、无凝露，环境温度要求低于40e。当海拔超过1000m或环境温度高于40e时，变频电源必须降容使用。环境气体为无腐蚀性、无尘埃、无引发火灾及爆炸性的气体。变频电源的冷却方式为水冷却和强迫空气冷却;变频电源柜体的标准防护等级为IP20或IP21，在用户有特殊要求时可提高至IP42或IP54.
基于变频电源的上述简单的环境要求，无论是工程设计单位或用户都会把它当成一般的中压开关柜或变压器来进行室内布置安装，通常将变频电源与其他电气设备同置一室。条件较好的会像设计变压器室一样单独设计变频电源室。大家普遍认为变频电源生产厂家已经充分考虑了变频电源的通风和冷却因素，因此，一般在安装上只采取提高室内净空高度或在外墙上安装轴流风机等简单措施。 航空地面电源，36V航空电源，400HZ变频电源，115/200V电源，27V直流电源，400HZ电源，航空电源
从电气角度来看，对变频电源采用与中压开关柜或变压器相似的安装布置方式无可非议。但如果从三者的功率损耗来看，它们之间有着不小的差别。产品变频电源油浸变压器干式变压器高压开关柜备注损耗(%)25223忽略不计变频电源损耗指在整个调速范围内，三者都属于率产品，损耗仅占其总功率的很小一部分。变频电源在额定频率和额定功率时的损耗为2%，但几乎没有经常在额定点运行的变频电源。它们在70%85%转速常规运行范围内的损耗约4%.以自来水行业常用的1000kVA变频电源为例，其常规调速运行时相应的损耗达40kW，这些损耗全部转化为热量。 油浸变压器的散热是通过绝缘油的循环将热量传递到变压器外壳的散热片上，再由流动空气带走热量，因此它的散热方式比空气冷却型变频电源好得多;干式变压器虽说与变频电源一样可以是强迫通风散热的，但变压器的发热时间常数长达数小时，而变频电源由于整流和逆变半导体器件的特性决定其发热时间常数只有几分钟，两者的耐超温能力是无法比拟的。
由此可见，变频电源的安装布置方式不能按常规的中压电气设备来对待，而必须充分考虑其室内冷却空气的温度。变频电源生产厂商通常在柜内安装离心式风机或柜顶安装轴流式风机，对整流器和逆变器的功率器件组进行强迫空气冷却，并提出了前述的环境要求，但他们没有对如何保证这些要求提出建议。此时若室内外空间无完善的空气交换系统，则变频电源散发出来的热量绝大部分滞留于室内，使变频电源的环境温度不断上升，空气冷却所需的环境条件就完全改变了。
