Abstract: The present disclosure relates to systems and methods to coordinate protective elements in an electric power system (EPS). In one embodiment, a system may include a Time vs Normalized Impedance Length subsystem to determine a first plurality of times of operation of a first protective element for a plurality of fault locations in the EPS and to determine a second plurality of times of operation of a second protective element for the plurality of fault locations in the EPS. A protective action subsystem may coordinate a response of the first protective element and the second protective element. The protective action subsystem may establish a pickup and a protective action for the second protective element. Upon detection of a fault in the EPS, one of the first protective action and the second protective action may be implemented based on one of the first pickup and the second pickup.

Abstract: A method for driving a power transistor includes comparing a measurement signal that is representative of a load current to a comparator threshold that corresponds to an overcurrent threshold; generating a first fault signal when the measurement signal exceeds the comparator threshold for a first time interval; generating a second fault signal when the measurement signal exceeds the comparator threshold for a second time interval that is greater than the first time interval; regulating a control voltage provided to the control terminal of the transistor to turn off the transistor in response to the second fault signal; and in response to the first fault signal, adjusting the control voltage to an adjusted voltage level in order to limit the load current to a reduced current level that is preconfigured to be greater than the overcurrent threshold. The adjusted voltage level is sufficient to maintain the power transistor in an on-state.

Abstract: A method for driving a power transistor includes comparing a measurement signal that is representative of a load current to a comparator threshold that corresponds to an overcurrent threshold; generating a first fault signal when the measurement signal exceeds the comparator threshold for a first time interval; generating a second fault signal when the measurement signal exceeds the comparator threshold for a second time interval that is greater than the first time interval; regulating a control voltage provided to the control terminal of the transistor to turn off the transistor in response to the second fault signal; and in response to the first fault signal, adjusting the control voltage to an adjusted voltage level in order to limit the load current to a reduced current level that is preconfigured to be greater than the overcurrent threshold. The adjusted voltage level is sufficient to maintain the power transistor in an on-state.

Abstract: A system to detect gate-open failures in a MOS based insulated gate transistor can include a detection circuit, including a first circuit configured to measure a drain-source voltage across the MOS based insulated gate transistor, a first comparator circuit can be configured to compare the measured drain-source voltage to a threshold drain-source conduction voltage indicating a conduction state of a channel of the MOS based insulated gate transistor, a second circuit can be configured to measure a gate voltage applied at a gate of the MOS-based insulated gate transistor, a second comparator circuit can be configured to compare the gate voltage applied at the gate to a threshold gate voltage for the MOS based insulated gate transistor to provide an indication of whether the gate voltage applied at the gate is sufficient to activate conduction in the channel and a logic circuit can be configured to detect a gate-open failure of the MOS based insulated gate transistor based on the conduction state of the channel

Abstract: A method and circuit for protecting circuit elements in a traffic control system from an overcurrent condition. In accordance with an embodiment, the circuit includes a current sensing element, a switching element, and a microcontroller. The circuit monitors first and second operating parameters and compares the first operating parameter with a first reference parameter and the second operating parameter with a second reference parameter. In response to the first operating parameter exceeding the first reference parameter and the second operating parameter exceeding the second reference parameter, the microcontroller generates a control signal to open the switching element.

Abstract: Systems and methods are provided herein for improving distance protection in transmission lines. Such systems and methods may involve receiving one or more current and voltage inputs, and determining, based on the one or more current and voltage inputs, one or more current and voltage phasors, wherein the one or more current and voltage phasors are determined using a short window phasor estimation. Such systems and methods may also involve determining, within a single power cycle and based on the one or more current and voltage phasors, a fault in a transmission line. Such systems and methods may also involve sending, to a distance protection element and based on the determination that the fault exists, a signal to clear the fault in the transmission line, and clearing the fault in the transmission line.

Abstract: An integrated circuit that may be employed as a smart switch is described herein. In accordance with one embodiment the integrated circuit includes a power transistor coupled between a supply pin and an output pin and further includes a control circuit configured to trigger a switch-on and a switch-off of the power transistor in accordance with an input signal. The control circuit is configured to trigger a switch-off of the power transistor when a load current passing through the power transistor is at or above a predetermined current and a supply voltage received at the supply pin is at or below a predetermined threshold voltage.

Abstract: An arc flash suppressor, system, and method are disclosed. The arc flash suppressor includes a main processor, a current sensor processor, a voltage sensor processor, a plasma ignition detector, and an arc flash extinguishing circuit. The current sensor processor is configured to detect a slew rate of an input current from a power source. The voltage sensor processor is configured to detect a slew rate of an input voltage from the power source. The main processor is configured to cause the arc flash extinguishing circuit to create a short circuit condition over the power source to extinguish an arc flash upon detection of a critical current slew rate, a critical voltage slew rate, and plasma ignition.

Abstract: A system and method of protecting the input components of a power supply. An input overcurrent protection module is provided, which may be implemented in firmware, which monitors the input current through an input interface of the power supply. When the input current exceeds a threshold current (i.e., a current above the maximum rating of an input component, such as an input cable), the input current protection module determines whether an input overcurrent event is occurring. When it is determined that an input overcurrent event has occurred, the input current protection module disables the output circuitry of the power supply and triggers a few timers. The input overcurrent protection module continues to monitor the input and, if the input current continues to exceed the threshold current, is configured to shut down the power supply. In this way, input components may be protected from overcurrent issues in high-power systems.

Abstract: A device for protecting an electronic computer against a short circuit. The electronic computer including a shunt resistor, a first computer pin and being coupled to at least one sensor comprising a first sensor pin and a second sensor pin. Furthermore including a transistor driving module having a first driving pin coupled to a first shunt pin, a second driving pin coupled to a positive power supply, a second shunt pin being coupled firstly to a first sensor pin and secondly to a first comparator pin of a comparator module and designed to no longer supply electric power to the sensor through the first sensor pin when a short circuit is detected at the sensor.

Abstract: A wireless-power-system includes a bridge-rectifier having first and second inputs coupled to first and second terminals of a coil, and an output coupled to a rectified voltage node. An excitation circuit is coupled to the first input. A protection circuit has a first connection node capacitively coupled to the first terminal. The protection circuit, in Q-factor measurement mode, clamps the first connection node when the first input is coupled to ground, and connects the first connection node to the rectified voltage node when the first input is coupled to a supply voltage. The protection circuit, in wireless power mode, is acting as one leg of the rectifier. A pass gate circuit is coupled between the first connection node and a sense node, and a sensing circuit is coupled to the sense node and measures a Q-factor of the wireless power system when the protection circuit is in Q-factor measurement mode.

Abstract: A protection relay connection assembly (10) for connecting a current transformer (14) and/or a voltage transformer (16) of an electrical network (12) to a protection relay (18) is provided. The protection relay connection assembly (10) includes a protection relay data acquisition board (20) and a protection relay connector (22). The protection relay data acquisition board (20) includes a first current mating member (24) connectable to a current measurement sensor (28), the current measurement sensor (28) being connectable in use to the protection relay (18) and/or a first voltage mating member (26) connectable to a voltage measurement sensor (30), the voltage measurement sensor (30) being connectable in use to the protection relay (18). The protection relay connector (22) includes a second current mating member (36) connectable to the current transformer (14) and/or a second voltage mating member (38) connectable to the voltage transformer (16).

Abstract: A gate driver circuit receiving an input control signal and providing a voltage at a gate terminal of a semiconductor switching device (e.g., an IGBT) may include: (i) a first voltage source providing a first voltage; (ii) a second voltage source providing a second voltage, wherein the first voltage is higher than the second voltage; and (iii) a selector circuit selecting, based on the input control signal's logic state, either the first voltage or the second voltage to be placed on the gate terminal of the semiconductor switching device.

Abstract: A drive circuit for driving a switching element on a SiC substrate, includes: a comparator for comparing a current flowing through the switching element with an overcurrent threshold; a determination unit for determining whether an overcurrent flows, based on a comparison result; a control unit for generating a drive signal for controlling a drive operation of the switching element based on a drive command, and for turning off the switching element when determining that the overcurrent flows; and a setting unit for variably setting the overcurrent threshold according to a physical quantity correlated with a voltage between main electrodes of the switching element.

Abstract: A battery pack includes a battery and a battery management system to control and manage charging and discharging of the battery. The battery management system includes an external terminal connected to a charger or an external electronic device, a cell terminal connected to the battery, a charge field effect transistor (FET) and a discharge FET connected between the external terminal and the cell terminal, a voltage sensor to measure a battery voltage of the battery, a comparator comparing the battery voltage with a reference voltage to determine whether the battery pack is in an overdischarged state, and a controller controlling the charge FET to be cut off to prevent a charge operation of the battery, if the comparator determines that the battery pack is in an overdischarged state.

Abstract: A safety circuit coupled between a first direct current (DC) circuit and a second DC circuit, wherein the first DC circuit supplies power to the second DC circuit. The safety circuit comprises a first series connection between positive poles of the first and second DC circuits (the first series connection comprising a first diode, a second diode and a first controllable switch), a second series connection between negative poles of the first and second DC circuits (the second series connection comprising a third diode, a fourth diode and a second controllable switch), a first energy storage device (coupled between the positive pole of the second DC circuit and the first terminal of the second controllable switch), and a second energy storage device (coupled between the negative pole of the second DC circuit and the first terminal of the first controllable switch).

Abstract: A closing control method for a high-voltage DC circuit breaker. The method comprises: closing breaking units of the transfer branch (2) group by group, then closing the main branch (1), and finally open the transfer branch. During the process of closing the breaking units of the transfer branch group by group, determine whether there is a fault in the power transmission system after closing current breaking unit group. if there is no fault, proceed to close the next breaking unit group until all breaking unit groups are closed before proceeding to the next step; if there is a fault, all the breaking units that have been closed are opened and the closing operation is ended. The method can pre-charge the power transmission system during the closing process of the high-voltage DC circuit breaker, and lower the overvoltage and system oscillation caused by the closing operation.

Abstract: An electrical link (8) between a DC high-voltage power source (2) and a user apparatus (5) including: an electrical conductor (4) surrounded by an insulating cover (4a), and an electrical protection device (3) that includes a conductive sleeve (7) arranged around the insulating cover (4a), a current generator (10) connected to a current injection point (30) of the conductive sleeve (7), a circuit breaker (9) arranged on the conductor and configured to cut off a current transiting through the conductor (4), and a detection module (11) connected to a current tap-off point (31) of the conductive sleeve (7) and to the circuit breaker (9) and configured to detect a current leak out of the conductor (4) and command the circuit breaker (9).

Abstract: A desaturation detector receives signals from a gate driver and circuitry that indicate whether a power semiconductor device is on and in desaturation. A logic circuit produces a signal as a function of the signals, from which a latch circuit produces an output signal. The signal has first and second values respectively in an as-designed condition, and in a short-circuit condition in which the power semiconductor device is on and in desaturation. The output signal has the first value, and transitioned and latched to the second value in response to a transition to the short-circuit condition, which causes the gate driver to switch the power semiconductor device off. And filter(s) reduce noise within the desaturation detector.

Abstract: A drive circuit includes: a control circuit providing control voltage to a control terminal of a switching device in accordance with input signal; and a capacitor having one end connected to a high side main terminal of the switching device, wherein the control circuit increases an output current capacity of the control circuit when the input signal becomes ON signal and voltage at the other end of the capacitor drops.

Abstract: An information processing apparatus includes: an interface; and a controller. The controller executes: storing, into a memory, history information relating to supply of electric power to an external device via the interface; rebooting when the reboot is required during supply of the electric power to the external device via the interface; and restarting control of the supply of the electric power to the external device via the interface, based on the history information stored in the memory.

Abstract: An electronic circuit for sensing a temperature rise in a power transistor device, the temperature rise caused by a current flow in the power transistor device. The power transistor device and a sense-FET are disposed on a substrate. The sense-FET senses a fractional portion of the current flow and outputs a current signal. A JFET has its drain connected to the drain of the power transistor device. The gate of the JFET is connected to the source of the power transistor device, such that when the power transistor device is on, the JFET is also turned on, and a drain voltage signal of the power transistor device is output at a second node of the JFET. A detection circuit receives the drain voltage signal and the current signal and outputs an alarm signal when the drain-source resistance of the power transistor device exceeds a combined threshold limit.

Abstract: A drive circuit includes: a control circuit providing control voltage to a control terminal of a switching device in accordance with input signal; and a capacitor having one end connected to a high side main terminal of the switching device, wherein the control circuit increases an output current capacity of the control circuit when the input signal becomes ON signal and voltage at the other end of the capacitor drops.

Abstract: A system and method for determining whether a cryptographic system is being observed for power consumption analysis in an attempt to decipher secret keys. The system comprises a first external connection to receive an input voltage, an internal voltage regulator with an external capacitor to produce the desired voltage for the cryptographic system. The internal voltage regulator typically includes a switch that passes current from the first external connection to the external capacitor. By monitoring the frequency at which the switch is activated, it is possible to detect that an external voltage is being applied to the external capacitor. This external voltage is typically used to perform SPA or DPA operations. Thus, the cryptographic system may cease performing any encryption or decryption operations if an external voltage is detected.

Abstract: The present invention discloses a system and method for leakage current protection. The leakage current protection method comprises the following steps: using a first control signal to control a first relay to be short circuit so as to generate a leakage current; a leakage current sensor generates an AC signal when the leakage current sensor detects the leakage current; using a leakage current signal processor to convert the AC signal to a DC signal; and when a latch circuit receives the DC signal, the latch circuit uses a second control signal to disconnect a second relay which is connected to electrical appliances which are needed to protect.

Abstract: A DC distance protection scheme for protecting a DC power transmission medium within the DC electrical power network. The DC distance protection scheme includes a protection device that is coupled in use to a DC power transmission medium. The protection device is operable to protect the DC power transmission medium from an electrical fault. The DC distance protection scheme also includes a measurement apparatus to selectively measure the current and voltage of the DC power transmission medium. In addition the DC distance protection scheme also includes a controller that is programmed to calculate an operating voltage of the DC power transmission medium using the measured current and voltage; perform a transient comparison between the calculated operating voltage and the measured voltage; and operate the protection device to protect the DC power transmission medium if the transient comparison meets a predefined criterion.

Abstract: A display may have an array of pixels illuminated using a backlight unit. The backlight unit may include multiple strings of light-emitting diodes (LEDs) and a boost converter for providing an output voltage to the multiple LED strings. The boost converter may have a single-phase single-switch, single-phase multi-switch, and/or multi-phase multi-switch configuration, where the switches are turned off when the peak current is reached. When transitioning from a single phase to a dual phase operation, the second (slave) phase current may be slowly ramped up. When transition from the dual phase to the single phase operation, the output voltage may be elevated while slowing ramping down the slave phase current. The boost converter may include a current detection circuit for adjusting the peak current of each phase to balance the average current levels. The boost converter may also include an in-rush current controller configured to sense a short fault.

Abstract: A power conversion device includes an input current sensor, an input voltage sensor, a power converter, an output voltage sensor for detecting an output voltage from the power converter, an output current sensor for detecting an output current value from the power converter, and a controller for controlling the power converter. The controller obtains an allowable current value that can be accepted from an external alternating current power source, and, controls the power converter so that the input current value does not exceed the allowable current value based on an input current value detected by the input current sensor. The controller detects an abnormality in the power conversion device based on the input current value, the input voltage, the output current value, the output voltage, and power conversion efficiency of the power converter.

Abstract: A power supply control device and a power supply control method capable of detecting a switch-related failure properly are provided. A power supply control device controls power supply via a switch. An output unit of a microcomputer produces a switching signal that instructs the switch to turn alternately on and off. A detection circuit reports a failure related to the switch if an accumulated period has reached or exceeded a threshold period. The accumulated period is accumulation of one or more periods when the switching signal instructs the switch to turn on but a comparator does not detect an on-state of the switch.

Abstract: A method determines a fault location in a fault on an electric line. Accordingly first reference voltage values are determined by current and voltage sampled values at a first line end and an impedance of the line. Second reference voltage values are determined by current and voltage sampled values at a second line end and the impedance. Fictitious first reference voltage values are calculated using a wave guiding model, describing the wave response of the line, with the first reference voltage values. The fictitious first reference voltage values, in the fault-free case, correspond to the second reference voltage values at the second line end. Fictitious second reference voltage values are calculated with the second reference voltage values. The fault location is determined by the first and second reference voltage values and the first and second fictitious reference voltage values.

Abstract: A control device for a power semiconductor switch includes an actuating device, which on a third control device terminal, upon the reception of a switching on command, generates an actuating voltage for the switching on of the power semiconductor switch and, upon the reception of an switching off command, generates an actuating voltage for the switching off of the power semiconductor switch, and a current detection circuit, which generates a first high-current signal if an actuating voltage assumes a voltage value at which the power semiconductor switch is switched on, and a primary voltage of the power semiconductor switch applied between first and second control device terminals exceeds a first power semiconductor switch primary voltage value.

Abstract: A controller for driving a power switch incorporates a hard turn-on disable circuit to prevent the power switch from turning on when the power switch is sustaining a high voltage value. The hard turn-on disable circuit includes a hard turn-on detection circuit and a protection logic circuit. The hard turn-on disable circuit is configured to block or to pass the system input signal to the normal gate drive circuit of the power switch depending on the detection indicator signal. In particular, the protection logic circuit blocks the system input signal VIN in response to a high voltage detection so that the power switch ignores the system input signal VIN, which may be erroneous, and the power switch is prevented from undesirable hard switching.

Abstract: An objective of the application is to provide a method for detecting a disturbance in a power system within a digital substation and an apparatus using the same. The method includes: sensing electrical parameters at an end of a transmission line; sampling the sensed electrical parameters; extracting traveling-wave information from high frequency component of the samples using a signal processing method; and if the extracted traveling-wave information indicating occurrence of the disturbance, transmitting the extracted traveling-wave information to an intelligent electronic device of the digital substation from a merging unit or non-conventional instrument transformer of the digital substation. As compared with the amount of the sample data of the sensed electrical parameters, the amount of the data representing the extracted traveling-wave information is reduced.

Abstract: A power adaptor (100) includes a power conversion unit (110) and a power line (121). The power conversion unit (110) charges a terminal (200) via the power line (121). The power adaptor (100) further includes a communication unit (130) and a data line (122). When the power adaptor (100) is coupled to the terminal (200), the communication unit (130) communicates with the terminal (200) via the data line (122). The power adaptor (100) charges the terminal (200) still using the power line (121). Furthermore, when the power adaptor (100) is coupled to the terminal (200), the power adaptor (100) communicates with the terminal via the data line (122). Compared with the method of data and power time-division multiplexing the power line, the heating phenomenon of the power line caused by an excessively high load of a signal isolation unit can be effectively avoided.

Abstract: A system for recharging a hybrid vehicle is provided with two motors and supplies commercial electricity to neutral points of the motors when a connection of a recharging stand is detected, forms an electricity loop through the neutral points of the first motor and the second motor according to a phase of the commercial electricity, and carries out a recharging mode by detecting at least a voltage of a DC link capacitor in a voltage converter, a voltage of a smoothing capacitor, and a battery voltage. According to the system, a current control value or a voltage control value is selected according to the recharging mode in order to recharge a battery based on the current control value or the voltage control value.

Abstract: A method and a device for controlling a voltage-controlled power semiconductor switch that can be switched off again, which has a first and a second connection and a control connection and which is conductive in the switched on state between the first and the second connection is provided. Firstly, a first control voltage comprising a first value is applied to the control connection to switch on the power semiconductor switch. Subsequently, conditions are detected, which indicate the progress of the switch-on procedure of the power semiconductor switch. As soon as conditions are detected, which are indicative of the fact that the switch-on procedure is deemed to be complete, a second control voltage comprising a second value higher than the first value is applied to the control connection to operate the power semiconductor switch in the conductive state with a higher control voltage to reduce its conduction losses.

Abstract: A system may comprise a first switch connected to an output of a first power source, a second switch connected to an output of a second power source, a first sensor connected to an output of the first switch, a second sensor connected to an output of the second switch, a third switch connected to the first sensor and the second sensor and connected to a load, and a control device connected to the first switch, the second switch, the first sensor, the second sensor, and the third switch.

Abstract: A transformer circuit includes a first transformer, a second transformer and an inductor, where a first terminal of the first transformer is coupled to a first terminal of the second transformer. The inductor is coupled between a second terminal of the first transformer and a second terminal of the second transformer.

Abstract: An electrical switch is disclosed for switching an electric current between a feed and an outgoer. The electrical switch can be mounted in a switchgear assembly and as a result electrical contact can be made with the electrical switch by a feed and an outgoer of the switchgear assembly. In one embodiment, the electrical switch includes an internal voltage tap for supplying power to a switch-internal electronics system and a changeover switch. The changeover switch adjusts the electrical connection between the feed or the outgoer and the internal voltage tap.

Abstract: A load driving device includes a switching element, a detector, a determination portion, a controller, and a threshold set portion. The switching element is arranged between a voltage source and a load, or between the load and a ground. The switching element is turned on to supply electric power from the voltage source to the load. The detector detects a current flowing in the switching element. The determination portion compares a detection value of the detector and a threshold value, and determines whether an overcurrent flows in the switching element. The controller controls the switching element based on a determination result of the determination portion. The threshold set portion sets the threshold value to a higher value as voltage of the voltage source is higher. As such, responsiveness of the load driving device is improved and the switching element is protected when a short-circuiting occurs.

Abstract: A semiconductor device includes a drive control circuit which drives a gate terminal of an IGBT. The drive control circuit includes a state machine control circuit, a base data memory and a current drive circuit which drives the IGBT on the basis of driving current information stored in the base data memory. The state machine control circuit reads out driving current information for rising stored in the base data memory a plurality of times in a predetermined time period and drives the current drive circuit at rising of a PWM signal, and reads out driving current information for falling stored in the base data memory a plurality of times in a predetermined time period and drives the current drive circuit at falling of the PWM signal.

Abstract: A protection circuit applied to a convertor including M pieces of driving switch modules each coupled to a power source, a load and one of M sets of driving signals. The ith driving switch module is controlled by the ith set of driving signals to selectively enable current paths between the power source and the load. A first sub protection circuit in the protection circuit includes a first protection switch module and a first detection module coupled to the first protection switch module. When the ith set of driving signals indicates an error event, the first protection switch module selectively couples the ith set of driving signals to a reference voltage according to a first detection signal. M and i are positive integers, and i is not larger than M.

Abstract: An overvoltage detection circuit coupled to an external power supply via a voltage supply line and comprising a transistor comprising first terminal coupled to the voltage supply line, second terminal coupled to the first terminal via a resistor, the second terminal coupled to a parasitic capacitor, the transistor configured to receive an overvoltage spike from the external power supply on the first terminal, and provide an output voltage on third terminal of the transistor to indicate detection of the overvoltage spike when it has a duration less than a time constant based on the resistor and the parasitic capacitor and amplitude that exceeds a threshold voltage of the transistor. The overvoltage detection circuit further comprises a monitor circuit configured to receive the output voltage from the transistor and provide a digital signal providing a notification of the detected overvoltage spike from the external power supply on the voltage supply line.

Abstract: An output-switch control system for an AC-DC power supply includes a push-button switch that has two triggers. The triggers correspond to different contacts of a detecting circuit, respectively. When the push-button switch is pressed to make the triggers and the contacts turn into a close-circuit state form an open-circuit state, the detecting circuit outputs a power-source-on signal, and when the push-button switch is pressed again, and either of the triggers and the contact turn into the close-circuit state form the open-circuit state, the detecting circuit outputs a power-source-off signal immediately. With the dual-transition signal certification at the contacts, safe output-switch control can be achieved, so as to provide a user with operational safety.

Abstract: An apparatus for controlling a high-power drive device external to a package of a motor drive circuit includes a motor drive circuit. The motor drive circuit includes a driver to control the high-power drive device based on a first reference voltage, a second reference voltage, and a control signal based on a received control signal. A fault circuit generates a failure indicator based on a voltage across terminals of the high-power drive device. A fault condition is based on the failure indicator. A first terminal coupled to the driver charges a node of the high-power drive device over a first length of time in response to an absence of the fault condition and a first level of the control signal. A second terminal coupled to the driver discharges the node over a second length of time different from the first length of time.

Abstract: A three-phase inverting apparatus and a control method and a paralleled power conversion system thereof are provided. The control method is suitable for controlling a three-phase inverter having a plurality of switch sets, a first inductor, a second inductor, and a third inductor. The control method includes following steps: obtaining a DC bus voltage, a plurality of phase voltages, and a plurality of phase currents; obtaining inductances of the first, the second, and the third inductors; calculating a plurality of switch duty ratios by a division-summation control means according to the DC bus voltage, the phase voltages, current variations of the phase currents, the inductances, and a switching cycle based on a sinusoidal pulse width modulation (SPWM); and generating corresponding control signals based on the switch duty ratios so as to control a switching of the switch sets.

Abstract: A control apparatus of a rotary machine controls drive of the rotary machine with winding groups. The control apparatus includes electric power converters in multiple systems, a failure detection portion, and a controller. The electric power converter has switching elements in an upper arm and a lower arm, and converts direct current power. The failure detection portion detects a failure of an electric power converter or a failure of a winding group. The controller operates the switching elements and controls electricity supply. When the failure detection portion detects the failure, the controller stops output to an electric power converter in a failure system, and the controller reduces a total number of times of switching per unit time of the switching elements in a normally operating system.

Abstract: A relay for control of a network protector located on a low voltage side of a transformer with a set of three phases, the relay having at least one route for power to be provided to the relay from at least one of the set of three phases taken from a transformer side of the network protector so that the relay may have power and be functional before the network protector is closed to provide power into a dead network.

Abstract: A method for detecting a short circuit on a multiphase electrical energy supply network line includes recording current and voltage sampled values and generating a fault signal upon a fault evaluation performed by an electrical protection device indicating a short circuit. Instantaneous reference voltage values are calculated from instantaneous current and voltage sampled values recorded before the short, and instantaneous comparative voltage values are calculated from instantaneous current and voltage sampled values recorded before the short and instantaneous current and voltage sampled values recorded during the short, to generate a fault signal quickly. Then a rectified reference voltage value is calculated from consecutive instantaneous reference voltage values, and a rectified comparative voltage value is calculated from consecutive instantaneous comparative voltage values.

Abstract: The present disclosure pertains to systems and methods for detecting faults in an electric power delivery system. In one embodiment, a system may include a data acquisition subsystem configured to receive a plurality of representations of electrical conditions. The system may also include a traveling wave differential subsystem configured to determine an operating quantity based on the plurality of representations of electrical conditions. The traveling wave differential subsystem may also determine a restraint quantity based on the plurality of representations of electrical conditions. The traveling wave differential subsystem may detect a traveling wave generated by the fault based on the plurality of representations. A fault detector subsystem may be configured to declare a fault based on a comparison of the operating quantity and the restraint quantity. A protective action subsystem may implement a protective action based on the declaration of the fault.