APPLICATION NOTES

TOSHIBA 

System Design

System design requires an intimate understanding of the customer’s system plus a complete understanding of how a drive / motor system responds.

The operating characteristics of each individual component of a system must be understood. When this is done, the individual drives and motors can be properly sized.

Each drive in a system must then be analyzed as to how it interacts with each other. For example, a system might have a chain that feeds logs from one section to another with each section having separate speed control. (The reason for this might be to allow the operator to increase or decrease spacing between logs.) If the first section is running faster than the second section (to decrease spacing) the surface friction of the log will cause the first section to push the second section. This means that the load is artificially high on the first section and the second section will be braking. A common DC bus might be employed to take advantage of recovering this energy differential. The sizing of the drives will also have to be increased to account for this “normal” operating condition.

Once sizing has been done, interfacing with the customer’s system is required. This can be analog and discrete inputs and outputs connected to a PLC or other control system. It can also be done through communication cards such as Modbus RTU, Modbus Plus, DeviceNet, Remote I/O, Profibus etc.

Often good communication is required between the drive supplier and the equipment supplier.

For example, if a drive is being installed on a circular saw, the saw manufacturer can provide information needed to determine the load the saw will impose.

In some cases, the end user may request that the drive / motor supplier directly interface with the equipment supplier with the expectation that the system integration will be seamless from their perspective.

In quick summary, once the customer’s needs are understood and the operation of the equipment is fully known, it is usually a straightforward process to engineer the system.