6
Chapter 1 Functional outline
VFDB2009 series dynamic
brake
system is equipment (DB unit) which controls the regeneration energy for
acquiring brake power. In order to acquire brake power other than DB unit, the braking resistor (DBR) which
consumes regeneration energy as heat, and the protection thermal relay (OCRY) which carries out electrical
overload detection are required.
The brake power gained due to the loss (a total of about 10 to 15%) by inside the inverter and inside the
motor because the inverter unit doesn
’
t have the ability to process the suppresion energy. When making the
continuous regeneration energy under operation, or the big regeneration energy in a sudden slowdown
consume by resistance and acquiring brake power, VFDB2009 series dynamic brake system is used.
VFDB2009 series dinamic brake system has compatibility in VFDB2002 series dynamic brake system,
attachment, and an operating method. The VFDB2002 series dynamic brake system applied to the present
system is exchanged for a VFDB2009 series dynamic brake system, and a simple substance and operation to
mix are possible.
VFDB2009 dinamic brake system is designed so that the content of a lead, mercury, cadmium, sexavalent
chrome, PBB, and PBDE may be based on the RoHS instructions which EU defines in consideration of the
influence on environment.
1.1
Operation principle
The suppression energy returns to the inverter unit when motor becomes the regeneration mode. The DC voltage of
inverter rises, because the inverter doesn't provide the regenerative function to the power supply. The DB unit detects this
DC voltage, operates the switching element (IGBT) in the unit, and consumes the regenarative energy to resistor (DBR)
for power generation. If the regenerative mode became finish,DC voltage returns to a normal value, switching element
(IGBT) becomes an immovable work.
* Regenerative mode
*
The case where the torque has been put out the motor to the machine`s called powering mode in the place where the
machine is driven with inverter. The motor rotation frequency rises more than the output frequency of the inverter, it enters
the state to have returned the torque from the machine to the motor under such a condition when the sudden
deceleration or a big load of GD
2
is naturally decelerated from this state for instance, this is called the regentive mode.
DB UNIT
Figure 1-1 basic circuit
INVERTER
UNIT
DBR
OCRY
DC/DC
IGBT
Summary of Contents for VFDB2009 Series
Page 1: ...VFDB2009 Operation Manual...
