This invention relates to improvements in or relating to current loop serial data communication system for wind electric farms.
In a wind farm, wind mills are commonly installed at a distance away from one another. Therefore operating parameters and data collection from individual mill is done through serial communication. The communication lines are connected to the electronic card in the control panel. In summer, lightning attacks the communication network in the wind farm. Thus severe damages occur to the electronic cards in the control panel. This causes down time of several mills and increases production loss.
The communication network as now known in the art for wind electric generators has certain limitations. The current loop communication cable enters directly into the communication card and are connected to opto coupled driver Ics. These Ics and allied protection circuits are unable to withstand the lighting attack and thus damage occurs to adjacent electronic cards.
Thus an object of the present invention is to propose such Infra Red current loop data communication system for use in wind farm, which ensures continued operation of (wind) electric generators even in the event of lightning attack.
The present invention will now be described in detail with reference to the accompanying drawings,
To describe the invention more clear we describe hereinbelow in — Figure 1 the conventional current loop communication; and
Figure 2 illustrates the improved Infra Red current loop data communication for wind electric farms.
Figure 1 shows conventional current loop data communication where a plurality of wind mill panels, namely 1, 2, 3 .... N are connected to each other and thus the current loop communication cable enters directly into the communication card and are connected to opto coupled driver ICs.
In Figure 2 Infra Red current loop data communication plurality of wind mill panels 1,2,3 .... N are connected to each other and thus the current loop communication cable enters in the control room is terminated about 450 mm away from the control panel. An unique electronic circuit which operates within the current loop power and the driver (drives IR LED) and receiver (receives signal from IR photo diode) are connected to the field communication cable. A similar opto electronics is made at control panel side. A pair of hollow tube or fiber optic cable of about 450 mm length is connected between the field and panel side optical components. The current loop communication thus established with the field network cable is kept away from the control panel. Because of this costly damage to control panel electronics is prevented from lightning attack.

WE CLAIM:
1. An improved infra red current loop data communication for wind
electric farms wherein a plurality of wind mill panels being connected to
each other and a current loop communication cable being entered in a
control room which being terminated away from the control panel, an
electronic circuit operates within current loop power, a driver (IR LED)
and a receiver being connected to said field communication cable; a
further opto electronics being adapted at the control panel side, a pair of
hollow tube or fibre optic cable being connected between field and panel
side optical components.
2. An improved infra red current loop data communication for wind
electric farms as claimed in Claim 1 wherein said control room is
terminated about 450 mm away from said control panel.
3. An improved infra red current loop data communication for wind
electric farms as claimed in Claim 1 wherein said receiver receives signals
from IR photo diode.
4. An improved infra red current loop data communication for wind electric farms substantially as herein described and as illustrated in the accompanying drawings.