過載瞬態(tài)仿真結(jié)果
額定穩(wěn)態(tài)長時間運(yùn)行時，單個IGBT芯片損耗為78.7W，單個Diode芯片損耗為23.4W。過載工況為每個芯片每10min內(nèi)可允許120% 過載，過載時間為持續(xù)1min，允許連續(xù)出現(xiàn)過載，即1H內(nèi)出現(xiàn)6次1.2倍過載。按1.2倍過載，單元輸出電流為356.4A時，單個IGBT芯片損耗為102W，單個Diode芯片損耗為28.9W。
圖8為1.2倍過載瞬態(tài)分析中，對IGBT芯片最高溫度的監(jiān)控曲線。從曲線可以看出，芯片在過載后第60s達(dá)到溫升最高值，隨后過載結(jié)束溫度下降，在第450s左右，溫度可以降到與穩(wěn)態(tài)時溫度一致。每次瞬態(tài)1.2倍過載均不會導(dǎo)致芯片最高溫度有相對升高，說明10min內(nèi)一次過載1min，有足夠的時間使過載溫度下降到穩(wěn)態(tài)溫度，不會因持續(xù)過載導(dǎo)致芯片最高溫度疊加升高。
1.2倍過載瞬態(tài)時芯片溫度曲線
1.2倍過載瞬態(tài)時芯片溫度曲線
圖8- 1.2倍過載瞬態(tài)時芯片溫度曲線
（6）測試數(shù)據(jù)
熱電偶埋在IGBT銅基板底部，熱電偶通過SatlonD3和催化劑606緊固在散熱器基板上，測試點為仿真溫度最高的IGBT芯片正下方。
IGBT正下方銅基板測試點示意圖01
IGBT正下方銅基板測試點示意圖01
圖9-IGBT正下方銅基板測試點示意圖01
IGBT正下方銅基板測試點示意圖02
IGBT正下方銅基板測試點示意圖02
圖10-IGBT正下方銅基板測試點示意圖02
模塊測試風(fēng)速按5m/s，與仿真風(fēng)速一致。測試時環(huán)境溫度20℃，測試點1為IGBT模塊的Tc溫度（殼溫），最高值為69℃，溫升49℃。
仿真得到的模塊最高殼溫Tc=86.7℃，溫升為46.7℃。仿真誤差為5%以內(nèi)，可以接受。說明仿真數(shù)據(jù)可以評估方案可行性及決定是否需要進(jìn)行打樣。
熱電偶監(jiān)測點溫度
熱電偶監(jiān)測點溫度
圖11-熱電偶監(jiān)測點溫度
3 結(jié)論
對于電力電子設(shè)備的散熱設(shè)計問題，采用基于FloEFD分析的散熱設(shè)計方法能較準(zhǔn)確的評估實際工況中的溫度duration of T4. This goes on and on. The time parameters caused by this are all set before leaving the factory. The process flow is as follows:
Use logo! 230rc basic model, because the time of the four time relays given in the flow chart is only set before leaving the factory, it is not equipped with text display LOGO! TD。 Therefore, 230V logo can be used! Of the product.
The digital and analog I / O allocation in application is described in the form of table.
Table 1, I / O resource allocation
Use logo! Experience of
LOGO! One of the advantages is that the text display windows are "standard keyboard characters", and Chinese characters are displayed, which is reflected by users, which is very convenient. With the continuous introduction of new versions of products, the functions and software capacity have increased. Therefore, we can also be used in more complex systems.
The function of text display is less than that of general-purpose display. If you can add the display of on / off symbols of the switching status of some soft components, such as in the form of indicator lights, it will be closer to
