Showing papers on "Fault indicator published in 1970"

Apparatus having automatic re-set means for detecting a fault current

Abstract: A device for detecting fault current. The device senses the current in a line and converts it to a proportional voltage signal. The voltage signal is used to switch a solenoid to first and second positions depending upon the value of the signal. The device will re-set itself after sensing a fault current when normal line current is restored.

Power transmission fault indicator with automatic reset means

Abstract: A fault indicator is provided which, in the event of normal power line operation, maintains itself in a status that reflects this normal condition. A surge or abnormal increase in the transmitted current reverses the direction of the current flow in at least a part of fault indicator circuit and causes the indicator to reflect the abnormal condition until the restoration of normal line conditions returns the current flow within the fault indicator circuit to its original direction to reestablish a normal condition indication.

On Determining the Reliability of Protective Relay Systems

Abstract: This paper lays the ground work for the statistical determination of the reliability of protective relay systems found in electric power systems. The reliability problem has two conflicting requirements: 1) failure to operate in the presence of a fault and 2) unnecessary operation when a fault occurs that the relay or relay system was set to ignore. It is not often treated in reliability literature.

Sequential Machines Capable of Fault Diagnosis

Abstract: By a checking sequence for a sequential machine, we mean an input-output sequence with a special property such that, when the input sequence is applied to the machine, the decision whether or not the machine operates correctly can be made by comparing the output sequence with the output of the machine.

Generation Of Fault Trees From SimulatedIncipient Fault Case Data

Abstract: Fault tree analysis is widely used in industry in fault diagnosis. The diagnosis of incipient or 'soft' faults is considerably more difficult than of 'hard' faults, which is the situation considered normally. A detailed fault tree model reflecting signal variations over wide range is required for diagnosing such soft faults. This paper describes the investigation of a machine learning method for the automatic generation of fault trees for incipient faults. Features based on the FFT (Fast Fourier Transform) of the time response simulations are used are used to provide a training set of examples comprising records of fault types, severity and feature list. The algorithm presented, called IFT, is derived from the ID3 algorithm for the induction of decision trees. A significant aspect of this approach is that it does not require any detailed knowledge or analysis of the application system. All that is needed is a 'black-box' model of the system; i.e. knowledge of what faults arise from measurable quantities taking on particular values. The proposed procedure is illustrated using detailed simulation results for a servomechanism typically found in machine tool applications and the results to date indicate the feasibility of the approach.

Speed and fault indicator for a model vehicle

Abstract: A visual indicator is provided which monitors the operating conditions of a model track system having electrically propelled vehicles and simultaneously provides an indication of the speed of the vehicle on the trackway and of any faulty conditions that may exist along the tracks. A semiconductor transistor circuit separates ripple voltage produced by commutation in the electrical motor that propels the vehicle from the full wave rectified voltage of the energizing source of the model system. Operation of the transistor circuit in response to ripple voltage drives a meter instrument calibrated to indicate speed of the vehicle, while deflections due to faults provide an indication of a fault at the location of the vehicle on the track.

Road vehicle electrical system with transducers detecting faults and producing unique outputs operating a receiving and display unit

Abstract: A fault detecting system for a road vehicle includes a plurality of fault transducers, each producing its own unique output in the event of a fault. The receiving and display unit is operable by these unique outputs for indicating each fault, and a single cable is used to connect all the transducers to the receiving and display unit.

Design of Automatic Detection Model for Single-phase Earth Fault in Distribution Network

Abstract: The current distribution network single-phase ground fault detection model knowledge expression is poor, its production process only based on the normal distribution network sample data, no single-phase ground fault data, did not make full use of a prior knowledge, resulting in low detection accuracy. The automatic detection model of single-phase earth fault of new distribution network is proposed. The fault characteristic vector is taken as the input vector, and the degree of matching between the input vector and the weight vector element is introduced as the second layer. The fault vector is used as the input vector, and the fault vector is used as the input vector. Node input, the second layer of the output as the third layer of the input, the model training, the output of the results of the distribution network is a single-phase ground fault detection results. The experimental results show that the proposed model has high detection accuracy.Â