Contactless Power Supply CPS
The initials CPS® designate the VAHLE Contactless Power Supply system. CPS® supplies mobile users with electric current. Electric current is transferred inductively from a stationary [primary] conductor to moving users. Unique to CPS® is the fact that the primary conductor can also be used for contactless data transfer. Continuous development since 1997 resulted in presently over 450 VAHLE CPS® installations worldwide in diverse industries. Invaluable know-how gained during these years enables VAHLE to implement customer specific solutions for complex application requirements.
Important criteria for the CPS® development were an economical wide range of capacities and application possibilities whereby high environmental compatibility was a major requirement. The relatively low conductor current of only 70A [for some specific applications even only 35A] resulted in a very high degree of efficiency with extremely high electro-magnetic compatibility [EMV/EMF]. In addition to current transfer, highly desirable features such as inductive data transmission and inductive track guidance have been integrated into the CPS® system to meet the material handling industries ever increasing requirements.
CPS Operating Principle:
VAHLE CPS® technology supplies electrical current without requiring mechanical contact. It employs the induction principle similar to the primary/secondary transfer of a transformer. On a transformer the primary and secondary windings are on a common, enclosed ferromagnetic core. CPS® technology ,,stretches,, the primary winding to an elongated conductor loop and places the secondary coil on an open ferromagnetic core. This allows for relative movement between the two coils. The use of a high frequency of 20 kHz optimizes transfer conditions.
The CPS® primary inverter converts the on site existing 3-phase alternating current into single-phase alternating current with a frequence of 20 kHz. An interface circuit is used to charge the primary cable with constant current. Current induced in the pick-up coil is rectified and adapted to consumer requirements.
With respect to the standard methods of transferring electrical current the mobile users [conductor systems, cable handling systems etc.] CPS® technology offers the following advantages:
- Maintenance free and therefore high system availability and low maintenance cost.
- No limit to travel speed or acceleration for the mobile user.
- Does not generate noise or contact brush residue as current transfer does not require mechanical contact.
- High tracking tolerance facilitated by air gap configuration between pick-up coil and primary cable.
- No deployment limitations in difficult environmental conditions such as dust , water, ice, strong winds etc.
- High efficiency achieved by selection of highest quality components and use best performance electronics available.
VAHLE CPS® technology links high efficiency, easy of installation and high reliability, resulting in the most advanced contactless current supply system.
In many cases it is necessary in addition to the electrical current for the drive motors, to also transmit control signals from a central PLC control installation to the mobile users. Since radio transmission is highly susceptible to interference, the existing primary cable is conveniently available to transmit data interference free. The integrated data transmission VAHLE Powercom® CPS® is configured to transmit interference free date at a rate of 187.5 kbit/s with a commonly available RS 485 interface as for example Profibus DP.
Advantage of Data Transmission with VAHLE Powercom® CPS®
- No additional components are required along the track when simultaneously using the primary cable for current supply and data transmission.
- Data rate up to 187.5 kbit/s.
- Absolute interference immune transmission due to high frequency separation from currently available radio transmission systems.
- Subsequent changes to the number of users as well as the system’,s environment can easily be accomplished without performing complex RF field analysis.
- Fully transparent transmission of the data signal without modifying software.
- Cat 05a en Contactless power system.pdfCatalog CPS