Protection of gate movement in hydroelectric power stations

Movement of the gates is an everyday task performed on a dam of hydroelectric a power station. This operation is often controlled remotely by measuring the positioning of the gates and a level of the current in the driving motors. This method of control cannot, however, detect anomalies, such as asymmetric movement of gates, faults in drive gearwheel etc. We therefore decided to devise a new improved system for the protection of gate movement which is described in our paper. It is based on measuring the forces applied to the transmission construction. The transducers with resistive strain gauges are mounted on the frame bearings and the strains are subsequently measured. The output signal from the transducer is proportional to a force applied to the frame. The transducers are installed at the points of the largest strain. For the protection against uneven movement of the left and right chains, the strain transmitters are inserted in the bearings of the main gearwheel, to measure the compression. The whole system is controlled by the microprocessor. The details on sensors, the electronic instrumentation needed, and the software of the controlling computer, are also described in the paper. This system has been tested, and regularly used, on the power stations of Drava river in Slovenia.