Delta Electronics ASDA-B Series manual „ Built-in Regenerative Resistor

Chapter 6 Control Modes of OperationASDA-B Series

6.6.3Regenerative Resistor

„Built-in Regenerative Resistor

When the output torque of servo motor in reverse direction of motor rotation speed, it indicates that there is a regenerative power returned from the load to the servo drive. This power will be transmitted into the capacitance of DC Bus and result in rising voltage. When the voltage has risen to some high voltage, the servo system need to dissipate the extra energy by using a regenerative resistor. ASDA-B series servo drive provides a built-in regenerative resistor and the users also can connect to external regenerative resistor if more regenerative capacity is needed.

The following table 6.H shows the specifications of the servo drive’s built-in regenerative resistor and the amount of regenerative power (average value) that it can process.

Built-in Regenerative Resistor Specifications

	Servo Drive	Resistance (Ohm)	Capacity (Watt)	Regenerative Power	Min. Allowable
				processed by built-in
	(kW)	(parameter P1-52)	(parameter P1-53)		Resistance (Ohm)
				regenerative resistor (Watt) *1
0.1		No built-in regenerative resistor		-	40
0.2		No built-in regenerative resistor		-	40
0.4		No built-in regenerative resistor		-	20
0.75		40	60	30	20
1.0		40	60	30	20
1.5		40	60	30	20
2.0		40	60	30	10

*1: Regenerative power calculation: The amount of regenerative power (average value) that can be processed is rated at 50% of the capacity of the servo drive’s built-in regenerative resistor. The regenerative power calculation method of external regenerative resistor is the same.

Table 6.H

When the regenerative power exceeds the processing capacity of the servo drive, install an external regenerative resistor. Please pay close attention on the following notes when using a regenerative resistor.

1.Make sure that the settings of resistance (parameter P1-52) and capacity (parameter P1-53) is set correctly.

2.When the users want to install an external regenerative resistor, ensure that its resistance value is the same as the resistance of built-in regenerative resistor. If combining multiple small-capacity regenerative resistors in parallel to increase the regenerative resistor capacity, make sure that the resistance value of the regenerative resistor should comply with the specifications listed in the above table.

3.In general, when the amount of regenerative power (average value) that can be processed is used at or below the rated load ratio, the resistance temperature will increase to 120°C or higher (on condition that when the regeneration continuously occurred). For safety reasons, forced air cooling is good way that can be used to reduce the temperature of the regenerative resistors. We also

6-32 Revision January, 2009