H02H3/40

Sensitive impedance-based string protection of multi-string and multi-stage capacitor

A protection and monitoring system, device, and method for an electric power system, including a capacitor bank having multiple strings in each phase, voltage and current measuring devices, and relays to protect this capacitor bank. Each string can have multiple capacitor units and each unit can consist of multiple capacitor elements. The method may include: determining steady state operating condition using the obtained current and voltages, calculating and storing present time impedance value of each string into memory, calculating the string per unit impedance incremental quantity, detecting capacitor element failure based at least in part on this incremental quantity and calculating number of failed capacitor elements for each event, accumulating the number of failed capacitor elements, and performing a protection action when healthy capacitor elements are subject to an overvoltage limit. The method may be inherently immune or otherwise insensitive to capacitor variations due to aging, temperature change, instrument transformers errors, inaccuracy in data acquisition, and inherent manufacturing unbalance.

DETERMINING A FAULT LOCATION ON A POWERLINE
20220128613 · 2022-04-28 ·

A method for determining a location of a fault on a powerline, comprising: obtaining, using a measuring device at a measurement location on the powerline, time-dependent data of a voltage on the powerline and of a current through the powerline at the measurement location, wherein the time-dependent data is obtained during a time period after fault inception; removing fundamental frequency components from the time-dependent data; calculating, from the time-dependent data, a virtual fault inductance for at least two different potential fault locations, by inputting the time-dependent data into an equivalent circuit model, by means of time-domain calculations on the nonfundamental frequency waveform components; and deriving, from the virtual fault inductance for each of the potential fault locations, a location on the line at which the virtual fault inductance is substantially zero.

Method for controlling a charging device of a vehicle and charging device of a vehicle for charging an electrical energy storage device of the vehicle

A method for controlling a charging apparatus of a vehicle, in particular an electric or hybrid vehicle, wherein the charging apparatus has a charging device including a protection and monitoring device. The vehicle includes a high-voltage on-board power system and an electrical energy storage apparatus connected to the high-voltage on-board power system. The method includes electrically connecting the high-voltage on-board power system to charging connections of an energy supply system by the charging apparatus. The charging connections include a neutral conductor, a protective conductor and at least one phase conductor. A protective conductor resistance is detected between the neutral conductor and the protective conductor by feeding in a test current by the protection and monitoring device. A frequency of the test current is filtered out of the compensation frequency range on a narrowband basis.

Method and protection device for generating an error signal indicating an error type of an error in a multi-phase electrical energy supply network

A method for generating an error signal indicating an error type of an error in a multi-phase electrical energy supply network. Measured values describe a current operating state of the network. The measured values are transmitted to a protection device. An evaluating device evaluates every possible loop of the network that can be affected with respect to the recognition of the error type of an error, by using the measured values. In order to be able to more reliably recognize the error type even under different network conditions, the measured values and/or values derived from the measured values are evaluated using at least two different protection criteria, for every possible loop. Each of the protection criteria is suitable for indicating an error type of an error present in the evaluated loop, and the error signal is generated in consideration of all available evaluation results of the protection criteria.

Method and protection device for generating an error signal indicating an error type of an error in a multi-phase electrical energy supply network

A method for generating an error signal indicating an error type of an error in a multi-phase electrical energy supply network. Measured values describe a current operating state of the network. The measured values are transmitted to a protection device. An evaluating device evaluates every possible loop of the network that can be affected with respect to the recognition of the error type of an error, by using the measured values. In order to be able to more reliably recognize the error type even under different network conditions, the measured values and/or values derived from the measured values are evaluated using at least two different protection criteria, for every possible loop. Each of the protection criteria is suitable for indicating an error type of an error present in the evaluated loop, and the error signal is generated in consideration of all available evaluation results of the protection criteria.

TRANSMISSION AND DISTRIBUTION SYSTEM WITH ELECTRIC SHOCK PROTECTION FUNCTION AND METHOD OF OPERATING THE SAME
20210351690 · 2021-11-11 ·

A transmission and distribution system with electric shock protection function includes a transmitting terminal and a receiving terminal. The transmitting terminal includes a switch, a current measurer, a signal generator, and a controller. The receiving terminal includes a filter. The switch is coupled to a first DC power and a transmission line. The current measurer is coupled to the transmission line, and measures a current of the transmission line and provides a current signal. The signal generator provides a disturbance signal to the transmission line. The controller receives the current signal and controls the switch. If the controller determines that the current signal contains the disturbance signal, the controller turns off the switch.

TRANSMISSION AND DISTRIBUTION SYSTEM WITH ELECTRIC SHOCK PROTECTION FUNCTION AND METHOD OF OPERATING THE SAME
20210351690 · 2021-11-11 ·

A transmission and distribution system with electric shock protection function includes a transmitting terminal and a receiving terminal. The transmitting terminal includes a switch, a current measurer, a signal generator, and a controller. The receiving terminal includes a filter. The switch is coupled to a first DC power and a transmission line. The current measurer is coupled to the transmission line, and measures a current of the transmission line and provides a current signal. The signal generator provides a disturbance signal to the transmission line. The controller receives the current signal and controls the switch. If the controller determines that the current signal contains the disturbance signal, the controller turns off the switch.

A METHOD, DEVICE, AND SYSTEM FOR ADAPTING DISTANCE PROTECTION AGAINST REACTANCE EFFECT DUE TO REMOTE INFEED AND FAULT RESISTANCE
20230327426 · 2023-10-12 ·

The present disclosure relates to a method for controlling a distance protection system, as well as a respective device and system for performing the method. Measurements are received. The measurements comprise current and/or voltage measurements at a first position along a transmission line for an electrical power system. A first impedance is computed from the received measurements. A fault location is determined from the computed first impedance and a first impedance boundary. Responsive to the determined fault location, a second impedance is computed. The fault location is redetermined from the computed second impedance and the first impedance boundary. The distance protection system is controlled based on the determined fault location or the re-determined fault location.

Method and device for timing in time-varying distance protection based on multiple lines in tower

A method and device for timing in time-varying distance protection based on multiple lines of a tower. The method includes: collecting an instantaneous current value at a time-varying distance protection installation location in the multiple lines of the tower, and acquiring preset parameters; calculating, according to the preset parameters and a multi-line ranging model, a multi-line ranging result; calculating, according to the preset parameters, the multi-line ranging result, and an adaptive calculation model, time of a section-II distance protection action and final time of a section-III distance protection action; and determining, according to the instantaneous current value, the preset parameters, and a cross-line failure auxiliary criterion model, final time of the section-II distance protection action.

METHOD AND DEVICE FOR LINE PROTECTION
20230349683 · 2023-11-02 ·

Disclosed is a method for determining the distance to a fault location of a power line to be protected in an electric power system, the method including: configuring the power line to be protected into a plurality of segments, obtaining a plurality of line settings separately for each of the plurality of segments configured, and using the line settings obtained to determine a fault location of the power line to be protected, wherein the line settings include at least one of impedance, resistance, reactance, length, compensation factor, angle. Also disclosed is an intelligent electronic device.