The invention is related to a monitoring and protection device of power distribution transformers on the low voltage side. Said device monitors in a permanent manner the functioning of the transformer and provides a record of all the information in case of a fault. Additionally, the invention device provides the protection of the transformer in case of a fault, allowing a partial impact on the service and preventing peak currents that may reduce the useful life of the transformer. The device has a remote communication module that allows the transmission of the recorded data, a control module that may be activated remotely and a visual alert module that reduces the risk in the handling of the device.

A method and a system of detecting winding fault during online operation of an electrical machine, said method comprising, acquiring a set of signals from the machine over a period, said set of signals comprising two or more magnetic flux signals, each flux signal obtained from a respective flux sensor positioned on the external surface of the machine; extracting an internal winding fault indicator from the set of signals; comparing the internal winding fault indicator with a baseline indicator; and determining the internal winding fault when the internal winding fault indicator deviates from the baseline indicator by a threshold.

Non-liquid immersed transformers and methods of measuring aging degree of the transformers' insulation are disclosed. The transformers comprise a solid insulation inside the conductive coil and one or more floating electrodes in the solid insulation. At least a part of the conductive coil and the one or more floating electrodes may form one or more capacitive elements, respectively. An electrical parameter, e.g. complex permittivity, of the capacitive element is measured and the aging degree is calculated as a function of the electrical parameter measurement.

An example method comprises receiving historical sensor data from sensors of components of wind turbines, training a set of models to predict faults for each component using the historical sensor data, each model of a set having different observation time windows and lead time windows, evaluating each model of a set using standardized metrics, comparing evaluations of each model of a set to select a model with preferred lead time and accuracy, receive current sensor data from the sensors of the components, apply the selected model(s) to the current sensor data to generate a component failure prediction, compare the component failure prediction to a threshold, and generate an alert and report based on the comparison to the threshold.

An alert system for a transformer includes a thermographic camera configured to capture thermal images of the transformer, a current sensor configured to generate a sensor signal indicating the current magnitude of a current outputted from the transformer, a storage configured to store a machine learning model, an alert device, and a processing unit configured to obtain image temperature values from the thermal images, obtain magnitude values from the sensor signal, obtain normal temperature values by using the machine learning model and the magnitude values, and instruct the alert device to deliver an alerting signal based on a result of comparison between the image temperature values and the normal temperature values.

An alert system for a transformer includes a thermographic camera configured to capture thermal images of the transformer, a current sensor configured to generate a sensor signal indicating the current magnitude of a current outputted from the transformer, a storage configured to store a machine learning model, an alert device, and a processing unit configured to obtain image temperature values from the thermal images, obtain magnitude values from the sensor signal, obtain normal temperature values by using the machine learning model and the magnitude values, and instruct the alert device to deliver an alerting signal based on a result of comparison between the image temperature values and the normal temperature values.

The invention provides a transformer short-circuit protection method and a transformer short-circuit protection device. The transformer short-circuit protection method includes: acquiring output voltages of a plurality of output lines of at least one winding on a low-voltage side of a transformer; and determining a short circuit according to the output voltages, and sending a protection signal when the short circuit is determined.

The invention provides a transformer short-circuit protection method and a transformer short-circuit protection device. The transformer short-circuit protection method includes: acquiring output voltages of a plurality of output lines of at least one winding on a low-voltage side of a transformer; and determining a short circuit according to the output voltages, and sending a protection signal when the short circuit is determined.

A method for partial discharge recognition in high voltage applications and a high voltage unit using the method, includes the steps of detecting a signal, transforming the signal from time to frequency domain, cutting frequencies above a defined threshold, and retransform the truncated signal from frequency to time domain. The information content of detected and truncated signals is determined and compared.

A method for partial discharge recognition in high voltage applications and a high voltage unit using the method, includes the steps of detecting a signal, transforming the signal from time to frequency domain, cutting frequencies above a defined threshold, and retransform the truncated signal from frequency to time domain. The information content of detected and truncated signals is determined and compared.