Abstract: The present invention relates to a method and a monitoring system, for monitoring a vacuum on-load tap changer. The tap changer includes a housing with insulating fluid, a diverter switch inside of the housing and including at least one movable contact and at least two vacuum interrupters, and at least one pressure sensor which measures the pressure in the housing. The method, which is performed by a processing circuitry in the system, includes determining a pressure signature, including two succeeding peaks within a time interval, continuously measuring the pressure, detecting when the measured pressure shows the pressure signature, determining, based on the measured pressure within the pressure signature, the time between the first rise in pressure and the second drop, and setting the determined time to represent the switch time of the diverter switch.

Abstract: An interlocking adapter in one aspect of the present disclosure includes a current path, an electric load, a switch, and a controller. The controller turns on and off the switch in synchronization with a change of an alternating-current voltage received from an electric outlet of an electric apparatus in response to reception of an interlocking command signal from a working machine so as to supply a load current from the electric outlet to the electric load. The controller turns on and off the switch at a specified ratio of a time every ½ cycle of the alternating-current voltage.

Abstract: Provided herein is a power distribution system comprising a feedback circuit including a transistor in series with a relay, the feedback circuit regulating regulate a main power path including a main power supply connected in series with an electric power converter. The power distribution system further comprises OR-ing controllers that regulate the main power path and a backup power path including a low-voltage battery. The power distribution system further comprises terminals through which power from the main power path or the backup power path is transmitted to respective components corresponding to channels. The power distribution system further includes a microcontroller that acquires data in each of the channels and control operations associated with each of the channels based on the acquired data.

Abstract: A method for controlling an electrical power which flows into or out of an electrical subnetwork via a connection point is disclosed. The subnetwork has at least one electrical load, and the electrical load is connected to a control device via a communication connection, the electrical power flowing via the connection point is measured and a maximum power consumption of the electrical load is set by means of the control device on the basis of the electrical power flowing via the connection point. A device for connecting a multiphase subnetwork, which has an energy production installation and an energy store, to a superordinate multiphase alternating voltage network is configured to transmit electrical power between the alternating voltage network and the subnetwork and comprises an AC/AC converter having a network connection, two inverter bridge circuits with an interposed intermediate circuit and a subnetwork connection.

Abstract: A control method includes sequentially updating a next cycle pulse width modulation command for each of an upper switch and lower switch of a phase leg of a power converter according to an order defined by timing of a rising edge of the next cycle pulse width command for one of the switches relative to a rising edge of a previous cycle pulse width command for the one of the switches.

Abstract: An ideal diode circuit is described which uses an NMOS transistor as a low-loss ideal diode. The control circuit for the transistor is referenced to the anode voltage and not to ground, so the control circuitry may be low voltage circuitry, even if the input voltage is very high, referenced to earth ground. A capacitor is clamped to about 10-20 V, referenced to the anode voltage. The clamped voltage powers a differential amplifier for the detecting if the anode voltage is greater than the cathode voltage. The capacitor is charged to the clamped voltage during normal operation of the ideal diode by controlling the conductivity of a second transistor coupled between the cathode and the capacitor, enabling the circuit to be used with a wide range of frequencies and voltages. All voltages applied to the differential amplifier are equal to or less than the clamped voltage.

Abstract: The present disclosure relates to an interface comprising: a terminal for delivering a DC voltage; a comparator for delivering a first signal representative of a comparison of the DC voltage with a high threshold; a comparator for delivering a second signal representative of a comparison of the DC voltage with a low threshold; and a circuit configured to: deliver successive pairs of values of high and low thresholds for a time period after the DC voltage crosses a first value of the low threshold; modify successive pairs of values of the thresholds based on the first and second signals to determine values of thresholds surrounding the DC voltage; and determining a current value of the DC voltage based on the values of thresholds surrounding the DC voltage.

Abstract: A voltage regulator for providing power to a system includes feedforward circuitry receiving a signal from the system indicating the current needed by the system, and the feedforward circuitry causes the voltage regulator to change the voltage regulator output current in response to the signal from the system.

Abstract: An intelligent fuseless switch includes a moving contactor, a switch, a base, and a vibration detection module. When the vibration detection module detects that vibration intensity is higher than a preset value, the electromagnetic trip device is triggered by the base to push the moving contactor to open a circuit. The power cannot be introduced into the house. This automatic power-off mode has an active protection effect. After the vibration detection module is installed, if it needs to be repaired, it can be directly replaced without removing the circuit breaker, thereby reducing the difficulty of maintenance greatly.

Abstract: Methods, systems, and computer readable mediums determining a system state of a power system using a convolutional neural network using a convolutional neural network are disclosed. One method includes converting power grid topology data corresponding to a power system into a power system matrix representation input and applying the power system matrix representation input to a plurality of convolutional layers of a deep convolutional neural network (CNN) structure in a sequential manner to generate one or more feature maps. The method further includes applying the one or more feature maps to a fully connected layer (FCL) operation for generating a respective one or more voltage vectors representing a system state of the power system.

Abstract: An apparatus according to an embodiment includes a control circuit to control operations of an inverter and a switch. The control circuit judges whether or not a power system has a power failure, based on values of the system voltage and a frequency of the power system; and calculates a phase difference between a phase of the output voltage of the inverter and a phase of the system voltage and generate, by means of the phase difference, an output frequency pattern for changing a frequency of the output voltage of the inverter. The control circuit, when it is judged that the power system has recovered from the power failure, controls the inverter to change the frequency of the output voltage of the inverter in line with the output frequency pattern, and closes the switch after the phase difference becomes smaller than or equal to a threshold.

Abstract: A capacitor bank which has a plurality of capacitor units, in which each capacitor has a plurality of electrical capacitor elements, and the capacitor units are divided into a plurality of groups of capacitor units. The arrangement has a plurality of group monitoring units, with one of the group monitoring units associated with each group of capacitor units. At least one of the group monitoring units is configured so that it monitors the respective group of capacitor units for a failure of a capacitor element in one of the capacitor units of the group and, when such a failure of a capacitor element is detected, transmits data which describe this failure of the capacitor element to a monitoring receiver.

Abstract: A power conversion system includes N power converters. Each power converter includes an input terminal, a first output terminal and a second output terminal. Each of the N power converters receives a DC power through the corresponding input terminal. The first output terminal of a first power converter of the N power converters and the second output terminal of an N-th power converter of the N power converters are connected in parallel to form an N-th total output terminal to output an N-th total output power. The first output terminal of an i-th power converter of the N power converters and the second output terminal of an (i?1)-th power converter of the N power converters are connected in parallel to form an (i?1)-th total output terminal to output an (i?1)-th total output power.

Abstract: A method and apparatus for secondary control in a power network. In one embodiment, the method comprises determining a frequency area controller error (ACE) equation for an area and a voltage ACE for the area; decomposing the frequency ACE equation and the voltage ACE equation to generate a first set of symmetric sequences for the frequency ACE equation and a second set of symmetric sequences for the voltage ACE equation, respectively, wherein the first and second sets of symmetric sequences represent positive and negative sequences; and implementing, by an area controller for the area, secondary control on each sequence in the first and second sets of symmetric sequences separately.

Abstract: A low voltage control system, a low voltage protection method for an electronic device, and a computer program product thereof are disclosed. The electronic device includes a power supply and a memory. The low voltage protection method for the electronic device includes the following steps: detecting a current voltage of the power supply; determining whether the current voltage is lower than a first voltage threshold; and if the voltage is lower than the first voltage threshold, a control module cutting off multiple access channels.

Abstract: A solar cell power conversion device is disposed between a solar cell and a consumer premises distribution system. A storage battery power conversion device is disposed between a storage battery and the consumer premises distribution system. When an AC effective voltage in the consumer premises distribution system deviates from a voltage range defined in accordance with dead zone information transmitted from HEMS, system voltage stabilization control for returning the AC effective voltage to fall within the voltage range is performed by control of active power and reactive power that are output from a first DC/AC conversion circuit and a second DC/AC conversion circuit.

Abstract: In order to create a full variable shunt reactor having two magnetically controllable high-voltage throttles which is compact and at the same time can also provide capacitive reactive power, auxiliary windings are used which are inductively coupled to the high-voltage throttles. The auxiliary windings are connected to at least one capacitively acting component.

Abstract: A method for controlling a power converter of a wind turbine power system connected to an electrical grid. The wind turbine power system has a generator and the power converter has rotor-side converter and a line-side converter. The method includes monitoring an electrical parameter of at least one of the wind turbine power system or the electrical grid. In response to detecting a transient event in the electrical grid, the method includes temporarily disabling the line-side converter of the power converter from the electrical grid. Either during the transient event or after the transient event is over, the method includes implementing a control action for the line-side converter of the power converter. Further, the method includes enabling the line-side converter of the power converter to the electrical grid.

Abstract: A smart switch allows distributed generators to “ride through” non-three-phase faults by very quickly detecting a non-three-phase phase fault, locating the fault, identifying the “responsive sectionalizer switches” that will be involved in clearing or isolating the fault, and selecting one of the responsive sectionalizer switches to direct back-feed tie switch operations. The responsive sectionalizer switches trip only the faulted phase(s), and the selected sectionalizer switch instructs a back-feed tie switch to close to back-feed the distributed generators prior to conducting the typical fault response operation. This typically occurs within about three cycles, and is completed before the normal fault clearing and isolation procedures, which momentarily disconnect all three phases to the distributed generators from the normally connected feeder breaker.

Abstract: A first converter station is part of a high voltage direct current transmission system that includes a DC transmission link connected to the first converter station a second converter station. A DC current and a DC voltage of the DC transmission link are sensed by the first converter station. It is determined that the sensed DC current is equal to or larger than a threshold current value, that the sensed DC current is equal to or larger than the threshold current value, and that at least a partial recovery of the sensed DC voltage has occurred. On the basis that it is determined that the at least a partial recovery of the sensed DC voltage has occurred, it is determined that a phase-to-ground fault has occurred. In response to determining that a phase-to-ground fault has occurred, a power delivered by the first converter station can be reduced.