GE DS200STBAG1ACB Gas turbine AI module

Refer to the motor manufacturer’s data to obtain the permissible overload (continuous stall torque) for 2 seconds. Then use this figure to calculate the intermittent torque limit for the motor for a 2- second duration. For this example, 3 times the nominal torque rating is assumed If the value of Pav is less than the supplied resistor’s continuous braking power rating (refer to the tables in section 4.7.1 Braking resistor data on page 24), then that resistor can be used. However, if Pav is greater than the resistor’s continuous braking power rating, as in this example, a higher rated resistor should be used to reduce the risk of the drive tripping under braking

Since braking is planned to occur intermittently

an external resistor can be rated for intermittent rather than continuous power dissipation so that the overload factor of the resistor can be used. This factor can be obtained from cooling curves for the resistor The cooling curves indicate that for a braking time of 1 second and repeat cycle time of 7 seconds, the overload factor (F) is 2.If the braking resistor is to be mounted inside the enclosure, make a note of this value; you will need it when calculating the enclosure size. In practice, use a resistor having a power rating higher than the calculated value. For this example: 1kW

Value of the braking resistor

In practice, use a resistor having a preferred value close to and lower than the calculated value. This is because the calculated value would cause the braking transistor to be switched on almost continuously during braking. In this case, the drive will not have full control of the DC-bus voltage. A lower value of braking resistor will cause the braking transistor to act as a chopper which will then allow the drive to control the DC-bus voltage more accurately. The reduction in value does not increase the power dissipation since the average voltage across the resistor is reduced by the braking transistor operating as a chopper. For this example, R = 10Ω.

 Company product range

----------------------Ruichang Mingsheng Automation Equipment Co., Ltd----------------------

PLC module, programmable controller, CPU module, IO module, DO module, AI module, DI module

Network communication module,

Ethernet module, motion control module, analog input module, analog output module, digital input module, digital output

Module, redundancy module, power module, relay output module, relay input module, processor module