Power Management with Han® PowerSwitch

The manufacture of high-tech products for the market of the future requires the use of complex but efficient manufacturing processes. With the aid of new control and wiring concepts such processes can be implemented efficiently.

Don't forget the power

In the field of communication between sensors, actuators and control systems, field bus systems have met with broad acceptance. However, a machine or plant can only fully come to life if it has been systematically provided with (electrical) energy for drive units and other loads. Nevertheless, in this area we often find conventional concepts of parallel wiring. What could be more logical than to apply the well-established field bus concept of intelligent communication to the power supply section of a plant? Each load is assigned a power branch which constantly communicates with the other users via a bus interface. Decentralised field equipment handles the control and monitoring of drives for conveyors, fans and pumps, for example. Power is supplied to the various branches via an “energy bus“.

PowerSwitch comes on the scene

PowerSwitch - Example of an Application

Within the PowerSwitch product group from HARTING there are numerous variants of intelligent field equipment available. Figure 1 shows a typical application of the PowerSwitch for the AS interface bus system (yellow bus line and black 24 V DC actuator supply). Apart from the control system proper it particularly monitors the protective functions which play a central role in the power section. Consequently, PowerSwitch is in a position to provide the device with effective protection against overloading and shorting. The monitoring of loads and the power branch can either be effected via the field bus or actually on the equipment using visual display elements.

The packaging is what matters

Very harsh local conditions often place high demands when it comes to reliably protecting the internal components of equipment. Moreover, the considerable time savings on assembly and maintenance work must not be cancelled out by inefficient termination techniques. PowerSwitch meets these requirements with a robust housing in conjunction with connectors which have been designed throughout as mating connectors with fast connection in mind. Proven components from the Han® connector range or the new patent rapid termination technique HARAX® provide an IP 65 degree of protection.

Power - supplied in a "T"

With the introduction of an "energy bus", similar to the use of serial field bus systems in signal processing, it is possible to minimise the amount of cable laying work for the power supply. However, the power must be reliably supplied and passed on from one branch to the next. With the PowerSwitch this "T-functionality" is realised externally in the counterpart of the power connector (fig. 1). Compared with a power distribution system within the equipment this principle has the advantage that for servicing purposes a PowerSwitch appliance can be separated from the power supply without affecting operation of the downstream equipment.

The step towards a "powerful" field bus system

PowerSwitch is in a position to handle all the control and monitoring tasks which are transferred from the central control box to the decentralised power branch. The step towards progressive cabling concepts in all areas of modern plant and machine construction is thus systematically supported. The requirement profile of the PowerSwitch varies considerably depending on the characteristics of the connected load, the conditions of use and the field bus system used. Bus systems with limited functionality, such as the AS interface, are ideal for operating and monitoring single loads. Profibus and Interbus applications, on the other hand, permit multiple interfacing with extended functionality, e.g. evaluation of additional I/O signals.

From PowerSwitch to Power-Manager

A second-generation PowerSwitch

Systematic further development of the PowerSwitch concept will provide a major supplement to the range of products. Apart from equipment where switching and monitoring functions are implemented with conventional electromechanical switching elements a family of equipment will increasingly become established which operates on the basis of solid-state switching elements. This step towards fully electronic field equipment will ultimately have a considerable impact on the external appearance of the PowerSwitch (fig. 2). The volume of the housing, and hence the space required in the plant, will be significantly reduced. The appliance can be connected up to the load with integrated moulded connectors by simply mating. Assembly time will be reduced to a minimum. What is more, compared with the electromechanical family of equipment an extended range of functions will open up which, for example, will include gentle start-up, rotation speed control and parameterisable monitoring of the load.

Always a good solution

The wide range of possible applications for decentralised Power-Management calls for optimised solutions. Apart from the electromechanical standard equipment for the AS interface and the fully electronic generation, the Power-Switch family therefore also offers customer-specific solutions in every case which permit customised integration of decentralised concepts in the power supply area.