XBTL1AB01
要对制动电阻进行评级，请计算有助于吸收制动能量的比例。
如果必须吸收的动能超过可能的值，则需要外部制动电阻器
总内部能量吸收。
内部能量吸收
制动能量由以下部件内部吸收：
 直流母线电容器Evar
 内部制动电阻器EI
 驱动Eel的电气损耗
 驱动Emech的机械损耗
能量吸收Evar的值可在制动电阻一章中找到（参见第48页）。
内部制动电阻器
两个特征值决定了标准制动电阻器的能量吸收。
 连续功率PPR是指在没有
制动电阻过载。
 大能量ECR限制可吸收的大短期功率。
如果在特定时间内超过连续功率，制动电阻器必须保持空载
相应的时期。
内部制动电阻器的特征值PPR和ECR可在制动章节中找到
电阻器（见第48页）。
电气损耗Eel
驱动系统的电损耗Eel可根据驱动的峰值功率进行估算。
大功耗约为峰值功率的10%，典型效率为90%。如果
减速期间的电流较低，功耗相应降低。
机械损耗Emech
系统运行期间的摩擦导致机械损失。机械损失可以忽略不计
如果系统在没有驱动力的情况下滑行至停车所需的时间远长于
使系统减速所需的时间。机械损失可根据负载扭矩和
电机停止的速度。
实例
具有以下数据的旋转电机减速：
 初始旋转速度：n=4000 min-1
 转子惯性：JR=4 kgcm2
 负载惯性：JL=6 kgcm2
 驱动器：Evar=23瓦，ECR=80瓦，PPR=10瓦
吸收能量的计算：
至EB=88 Ws。忽略电气和机械损失。
在此示例中，直流母线电容器吸收Evar=23 Ws（该值取决于设备类型）。
内部制动电阻器必须吸收剩余的65瓦。它可以吸收ECR=80 W的脉冲。如果
负载减速一次，内部制动电阻足够。

To rate the braking resistor, calculate the proportion contributing to absorbing braking energy. An external braking resistor is required if the kinetic energy that must be absorbed exceeds the possible total internal energy absorption. Internal Energy Absorption Braking energy is absorbed internally by:  DC bus capacitor Evar  Internal braking resistor EI  Electrical losses of the drive Eel  Mechanical losses of the drive Emech Values for the energy absorption Evar can be found in chapter Braking Resistor (see page 48). Internal Braking Resistor Two characteristic values determine the energy absorption of the standard braking resistor.  The continuous power PPR is the amount of energy that can be continuously absorbed without overloading the braking resistor.  The maximum energy ECR limits the maximum short-term power that can be absorbed. If the continuous power was exceeded for a specific time, the braking resistor must remain without load for a corresponding period. The characteristic values PPR and ECR of the internal braking resistor can be found in chapter Braking Resistor (see page 48). Electrical Losses Eel The electrical losses Eel of the drive system can be estimated on the basis of the peak power of the drive. The maximum power dissipation is approximately 10% of the peak power at a typical efficiency of 90%. If the current during deceleration is lower, the power dissipation is reduced accordingly. Mechanical Losses Emech The mechanical losses result from friction during operation of the system. Mechanical losses are negligible if the time required by the system to coast to a stop without a driving force is considerably longer than the time required to decelerate the system. The mechanical losses can be calculated from the load torque and the velocity from which the motor is to stop. Example Deceleration of a rotary motor with the following data:  Initial speed of rotation: n = 4000 min-1  Rotor inertia: JR = 4 kgcm2  Load inertia: JL = 6 kgcm2  Drive: Evar = 23 Ws, ECR = 80 Ws, PPR = 10 W Calculation of the energy to be absorbed: to EB = 88 Ws. Electrical and mechanical losses are ignored. In this example, the DC bus capacitors absorb Evar = 23 Ws (the value depends on the device type). The internal braking resistor must absorb the remaining 65 Ws. It can absorb a pulse of ECR = 80 Ws. If the load is decelerated once, the internal braking resistor is sufficient.