The use of drives is common in control systems. In many cases it is beneficial to connect multiple drives to a common DC bus. When connected in this manner power can flow freely between the drives. Thus if one drive is in regeneration, it can supply power back to the DC bus. If the other drive is consuming power, the regenerating drive can supply the consuming drive with power thereby reducing energy consumption. Unfortunately, this configuration can also cause problems. If current flowing between drives is not limited, excessive stress can be placed on components receiving power from one or more of the drives via the DC bus. This often results in blown fuses or damaged components. Replacing such components incurs additional cost, not only in the cost to replace, but also in the down time of the system while components are replaced.
Therefore, what is needed is a way to protect the components from excessive current and the resulting damage the current may cause while also optimizing the flow of current and power consumption of the system. Other advantages will be apparent to those skilled in the art in view of the following disclosure of the invention and detailed description of embodiments.
USPTO Backgrounds
USPTO Backgrounds