原料氣壓縮機電機采用英威騰GD5000矢量型高壓變頻器驅(qū)動,主要參數(shù)如下:
英威騰GD5000系列矢量型高性能變頻器采用電壓源型單元串聯(lián)多電平高-高解決方案,直接6kV輸入、6kV輸出,接線簡單、控制靈活。控制系統(tǒng)采用DSP+FPGA+ARM三核技術(shù),對此種轉(zhuǎn)矩波動大的螺桿式壓縮機采用無PG(速度傳感器)的電壓開環(huán)(SVC)控制。一方面可輕松實現(xiàn)低轉(zhuǎn)速、大轉(zhuǎn)矩的帶重載啟動;另一方面,當(dāng)負(fù)荷波動瞬間轉(zhuǎn)矩增大時,內(nèi)置的DSP高速數(shù)字處理芯片可在100毫秒內(nèi)迅速降低運行轉(zhuǎn)速,提高輸出的電磁轉(zhuǎn)矩,防止因負(fù)載瞬間波動電流突然增大造成的設(shè)備頻繁跳閘,滿足現(xiàn)場運行工況要求。此外,對原料提純分離中的壓縮機組使用高壓變頻調(diào)速還有如下幾大優(yōu)勢:
電機為額定頻率60HZ的變頻電機,采用直驅(qū)方式,中間省去了增速箱等附屬裝置,降低了系統(tǒng)損耗。使用變頻傳動,滿足轉(zhuǎn)速輸出要求,其輸出頻率范圍0.5~120HZ,頻率分辨率0.01HZ;提高了傳動效率和控制精度。
采用DCS集中控制,起停采用現(xiàn)場硬接線按鈕,不僅滿足了設(shè)備運行的安全可靠,而且還提高了工藝流程優(yōu)化調(diào)整和監(jiān)控的實時性和靈活性。其系統(tǒng)控制圖如下所示:
原料氣儲罐容積有限從而造成壓縮機吸氣壓力不穩(wěn)定,負(fù)荷隨時間無規(guī)律波動。使用變頻調(diào)速可在壓縮機出口加裝壓力傳感變送器,變頻器可根據(jù)負(fù)荷變化實時調(diào)整運行轉(zhuǎn)速,實現(xiàn)輸出壓力恒定的閉環(huán)控制。運行頻率越低,制冷壓縮機的能耗也越低,從而在滿足工藝要求的條件下能實現(xiàn)一定的節(jié)能降耗。
化工企業(yè)生產(chǎn)設(shè)備繁多,經(jīng)常大批量同時啟動時容易造成廠內(nèi)母線電壓陡降,引起設(shè)備欠壓跳閘。GD5000系列變頻器具有優(yōu)良的抗電網(wǎng)電壓波動性能。網(wǎng)側(cè)電壓在+10%~-15%之間波動時可做到滿載輸出。同時具有AVR功能,能夠根據(jù)母線電壓的波動自動調(diào)整輸出電壓。網(wǎng)側(cè)電壓在短時間小于85%~65%額定值或大于110%~120%額定值時,高壓變頻器降額運行不停機,可保證壓縮機持續(xù)運行。
?作為工藝循環(huán)中的關(guān)鍵負(fù)載,GD5000系列變頻器具有功率單元工作情況(溫度、直流母線電壓、電流等)的實時監(jiān)控和單元自動旁路功能。
5.結(jié)束語encoder speed to motor speed is: I. the accuracy of coding / motor calibration coefficient directly affects the accuracy and rapid response ability of the equipment. Its calculation principle is to sample and calculate the average value, and then take the difference between the average value and the theoretical value as the reference value of calibration coefficient. The more samples, the closer to the actual value. This program selects 400 samples. Since only one data can be sampled in a scanning period, if an inappropriate number is selected, there may be response lag or great fluctuation.
As shown in Section 16 of the main program:
In the program, each scan reads a value from the array, and then sends it to the cumulative value (md10) for addition until 400 numbers are taken and the average value is calculated. The result is subtracted from the theoretical value (MD300) to obtain the correction coefficient (wr251)
The judgment and correction of deviation in the system is also a part of the main calculation of this program. In this system, when the speed is determined, the rotating speed of the cutter is constant. When the cutter rot