DANFOSS VLT5000 inverter

DANFOSS: VLT5000 inverter

■ Introduction

The built-in load sharing of the VLT 5000 series makes it possible to connect more VLT converters via the DC bus. The built-in load sharing option is only available for the VLT Series 5000 extension Unit (EB).

The purpose of load sharing is briefly introduced, connecting multiple VLT converters to the same DC bus has the following advantages:

● Energy saving:

The energy released from the motor running in regenerative mode is fed to other VLT converters running in motor mode. Another option is to use brake resistors on each individual drive to consume energy when the motor is running in regenerative mode.

● Brake resistance:

In dynamic applications, brake resistors are often required. When load sharing is used, only one common brake resistor is needed, not the brake resistor for each drive.

● Power backup:

When the main power supply fails, the DC bus provides backup power. Customers can now shut down the process or keep the process running in a controlled manner.

■ Normal

The number of VLT converters that can be connected together is in principle unlimited, but the connected VLT converters must be of the same voltage (200-240V or 380-500V).

Depending on the way the VLT converters are connected to each other, it is necessary to use a line reactor in the main power supply and a fuse in the DC bus.