3.7.2 Variable speed drives (VSD)
Variable speed drives (VSD, see Section 3.6.3) for compressors find applications mainly when the process air requirements of the users fluctuate, over times of the day and days of the week. Conventional compressor control systems such as load/unload, modulation, capacity control and others, try to follow this change in the air demand. If this leads to high switching frequencies and high idle time, a consequential reduction in the energy efficiency takes place. In VSD compressors, the speed of the electric motor is varied in relation to the compressed air demands, resulting in a high level of energy savings.
Studies show that a majority of compressed air applications have moderate to large fluctuations in air demand and hence there is great potential for energy savings by the application of variable speed driven compressors.
3.7.3 High efficiency motors (HEM)
Although a formal definition for a high efficiency motor does not exist, these components are generally classified as motors where losses have been reduced to the absolute minimum. High efficiency motors minimise electrical and mechanical losses to provide energy savings. Various classifications exist worldwide to differentiate high efficiency motors from others. Examples are EFF1, NEMA premium, etc. (see Section 3.6.1).
3.7.2 變速驅動裝置
壓縮機變速驅動裝置的應用主要是當製程需用壓縮空氣量時刻或波動的情形用來調節。傳統的壓縮機控制系統如加載/卸載、模組化、容量控制等試圖根據空氣需求的改變而改動。這會因為切換頻次過高及空轉機會過高導致發生能效降低的情事。
壓縮機變速驅動裝置其馬達的轉速可以依據壓縮空氣需求量變動而變速，而有高水準的節能效果。
研究發現，大多數的壓縮空氣應用，都有中到大的空氣需求波動，所以使用變速驅動馬達有很大的節能潛力。
3.7.3 高效型馬達
雖然至今還沒有正式的高效型馬達的定義存在，但一般分類是將馬達的損失減少到絕對低的情況較高效型馬達其電力損失和機械損失降到最小而有節能效果。全世界各地都有個中種不同的高效型馬達分類，如EFF1, NEMA頂級等。
3.7.2 Variable speed drives (VSD) 變速驅動裝置
None. 無
3.7.3 High efficiency motors (HEM) 高效型馬達
●current drawn is lower 電流消耗降低
●heat generated is lower. 發熱量降低
3.7.2 Variable speed drives (VSD)
Variable speed drive compressors are appropriate for a number of operations in a wide range of industries, including metal, food, textile, pharmaceutical, chemical plants, etc. where there is a highly fluctuating demand pattern f or compressed air. No real benefit can be achieved if the compressor operates continuously at its full capacity or close to it (see Examples, below).
VSD compressors may be applied into an existing compressed air installation. On the other hand, VSD controllers could be integrated into existing fixed speed compressors; however, better performances are obtained when the VSD controller and the motor are supplied in conjunction since they are matched to give the highest efficiency within the speed range. VSD applications should be limited to more up- to-date compressors due to possible problems with older compressors. The manufacturer or CAS expert should be consulted if in doubt.
Many CASs already have a variable speed driven compressor so the applicability across industry for additional variable speed compressors is some 25 %. The savings can be up to 30 %, although the average gain in a CAS, where one compressor with a variable speed drive is added, is about 15 %. It is likely that more CASs can employ variable speed driven compressors to their advantage.
3.7.3 High efficiency motors (HEM)
Motor losses are independent of where and what for the motor is used for. This means that high efficiency motors can be used almost anywhere. High efficiency motors are already used in most large applications (75 %); the majority of the remaining 25 % are smaller systems.
3.7.2 變速驅動裝置
VSD壓縮機廣泛適用於一些工業，如金屬、食品、紡製、醫藥、化學等工廠，這些工廠都有高波動的壓縮空氣的需求態樣。
VSD壓縮機或許可以應用到既有壓縮空氣設施當中同樣的VSD空製氣也可以整合到既有的定速行空壓機。不過VSD控制器與馬達一整套一起裝設其性能匹配可以在轉速範圍內有最佳效率而得到會有較好的表現。
一些壓縮空氣系統已經有VSD壓縮機，所以其應用性在工業界需增加VSD壓縮機大約有25%，雖然壓縮空氣系統平均可以節省到30%，但光一台壓縮機裝了變速驅動裝置就有約15%的節省，所以看來壓縮空氣系統採用變速驅動有其利益。
3.7.3 高效型馬達
雖然至今還沒有正式的高效型馬達的定義存在，但一般分類是將馬達的損失減少到絕對低的情況較高效型馬達其電力損失和機械損失降到最小而有節能效果。全世界各地都有個中種不同的高效型馬達分類，如EFF1, NEMA頂級等。
3.7.2 Variable speed drives (VSD)
Energy typically constitutes about 80 % of the life cycle costs of the compressor, the balance of 20 % comprises investments and maintenance. An installation, where (conservatively estimated) 15 % energy is saved owing to using variable speed drives, saves 12 % life cycle costs, whereas the additional investment for the variable speed compressor (instead of a traditional one) adds only some 2 to 5 % to the life cycle costs.
3.7.3 High efficiency motors (HEM)
Motor losses are independent of where and what for the motor is used for. This means that high efficiency motors can be used almost anywhere. High efficiency motors are already used in most large applications (75 %); the majority of the remaining 25 % are smaller systems.
3.7.2 變速驅動裝置
壓縮機其使用年限中能源使用佔了80%的成本其他20%為投資與維護成本。一套設施保守估計中有變速驅動可以省15%的能源，全年限省12%的成本；然而以變速驅動壓縮機取代傳統的壓縮機，其投入成本只占全使用年限的2~5%而已。
3.7.3 高效型馬達
在馬達全使用年限看來即使小到1~2%的能效貢獻，但累計起來就很可觀。
Energy Efficiency (2009) 3.7.2、3.7.3
