在制動電阻選型過程中需要考慮的兩大主要因素是功率和阻值，而對于溫度的考量，在現(xiàn)行的國家標(biāo)準(zhǔn)中，并沒有關(guān)于制動電阻溫度的規(guī)定，而且現(xiàn)行的《電阻器基本技術(shù)條件》中關(guān)于電阻器極限溫升的規(guī)定也只從電阻器的運(yùn)行狀況和人身安全角度考慮。
但是在制動系統(tǒng)中，除了要考慮電阻的運(yùn)行情況外，還要從整個制動系統(tǒng)來衡量，比如在電梯系統(tǒng)中如果機(jī)房溫度過高，會對控制柜的變頻器等各種電子設(shè)備的散熱產(chǎn)生影響。我們都知道，制動電阻主要是將再生電能轉(zhuǎn)化為熱能散發(fā)到空氣中，直接影響的是整個制動系統(tǒng)的工作環(huán)境溫度。
因此在選型時需要綜合考慮電阻的使用環(huán)境等再確定功率和阻值，并且在安裝操作中還需要注意以下問題：
1、避免將制動電阻和變頻器安裝的太靠近。
2、必須保證制動電阻有足夠的的散熱空間，必要時安裝散熱裝置。
3、電阻的接頭處必須安裝穩(wěn)固，避免電纜因長時間高溫受損。
4、連接電纜長度不宜過長，避免斬波干擾。
In the selection process of brake resistance, two main factors need to be considered are power and resistance value. For the consideration of temperature, there is no stipulation on the temperature of brake resistance in the current national standard. Moreover, the stipulation on the limit temperature rise of resistor in the current Basic Technical Conditions of Resistors only considers the operation condition and personal safety of resistor.
But in the braking system, besides considering the operation of resistance, it also needs to be measured from the whole braking system. For example, if the room temperature is too high in the elevator system, it will have an impact on the heat dissipation of various electronic equipment such as the frequency converter of the control cabinet. As we all know, brake resistance mainly converts regenerated electric energy into heat energy and emits it into air, which directly affects the working environment temperature of the whole brake system.
Therefore, when choosing brake resistance, we need to consider the use environment of resistance comprehensively to determine the power and resistance value. In addition, we need to pay attention to the following problems in installation operation:
1. Avoid installing brake resistance and frequency converter too close.
2. It is necessary to ensure that the brake resistance has enough heat dissipation space and install heat dissipation devices when necessary.
3. The joint of resistance must be installed firmly to avoid cable damage due to long time high temperature.
4. The length of connecting cable should not be too long to avoid chopper interference.
