A method controls a converter assembly which has a line-commutated converter. The line-commutated converter has an alternating voltage terminal which can be connected via a phase conductor to an alternating voltage network. The converter assembly further has a switch module branch which is arranged serially in the phase conductor and which contains a series circuit of switch modules at each of the terminals of which bipolar voltages can be generated which add up to a branch voltage. A connection voltage to a connection point between the switch module branch and the converter is controlled by adjusting an amplitude of a positive sequence component of the branch voltage. The converter assembly is configured to carry out a control method for controlling the converter assembly.

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. The device also comprises a control device which is configured to set the electrical powers flowing via the individual phases of the subnetwork connection on the basis of power values of the energy production installation and/or of the energy store by suitably controlling the inverter bridge circuits of the AC/AC converter.

An alternating current electrolysis system, as well as a method and a device for controlling the alternating current electrolysis system are provided. The method includes: acquiring a voltage amplitude at an alternating current side of an electrolysis rectification power supply; and modifying an output parameter of the electrolysis rectification power supply based on the voltage amplitude. Compared with the conventional technology, the problem of oscillation of a power grid due to unbalanced power of the alternating current electrolysis system is effectively solved, thereby facilitating normal operation of a electrolysis station.

A device for connecting to a high-voltage grid carrying an AC voltage and having a plurality of phases, includes an active part having at least one phase connection for connecting to a phase of the high-voltage grid, at least one step winding connected downstream of one of the phase connections and having a plurality of taps, a tap changer having, for each step winding, a selector for currentlessly switching over from a current to a desired tap of the step winding, and a load changeover switch connected downstream of the selector in series for commutating the current from the current to the desired tap, for avoiding a high short-circuit current in the step winding or in the tap changer. An impedance unit, having an impedance to be switched between a low impedance and a high impedance, is disposed between each selector and each load changeover switch.

Waveforms in power grids typically reveal a certain pattern with specific features and peculiarities driven by the system operating conditions, internal and external uncertainties, etc. This prompts an observation of different types of waveforms at the measurement points (substations). An innovative next-generation smart sensor technology includes a measurement unit embedded with sophisticated analytics for power grid online surveillance and situational awareness. The smart sensor brings additional levels of smartness into the existing phasor measurement units (PMUs) and intelligent electronic devices (IEDs). It unlocks the full potential of advanced signal processing and machine learning for online power grid monitoring in a distributed paradigm. Within the smart sensor are several interconnected units for signal acquisition, feature extraction, machine learning-based event detection, and a suite of multiple measurement algorithms where the best-fit algorithm is selected in real-time based on the detected operating condition. Embedding such analytics within the sensors and closer to where the data is generated, the distributed intelligence mechanism mitigates the potential risks to communication failures and latencies, as well as malicious cyber threats, which would otherwise compromise the trustworthiness of the end-use applications in distant control centers. The smart sensor achieves a promising classification accuracy on multiple classes of prevailing conditions in the power grid and accordingly improves the measurement quality across the power grid.

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.

A system for load balancing on a multi-phase power line connected to a single phase lateral power line, includes a contactor configured to selectively connect each phase of the multi-phase power line to the single phase lateral power line. There is a phase change device connected in parallel with the contactor and a controller. During the phase change state, the controller connects the input of the phase change device to the multi-phase power line and connects the output of the phase change device the single phase lateral power line. The controller causes the phase change device to output a voltage to the single phase lateral line initially aligned with the first phase and then rotated to align with the second phase and causes the contactor changes connection to the second phase of the multi-phase power line and disconnect the phase change device from the power lines.

A method identifies asymmetrical vibrations during the operation of an electric device which is connected to a high-voltage grid. Vibrations of the electric device are detected using vibration sensors which provide measured values on the output side. The measured values and/or values derived from the measured values are transmitted to a communication unit via a close-range communication connection. The measured values and/or the values are transmitted by the communication unit to a data processing cloud via a far-range communication connection. The measured values are separated into frequency components by the data processing cloud using a Fourier transformation, thereby obtaining a frequency spectrum. Odd and even frequency components of the frequency spectrum are ascertained based on a base frequency of the high-voltage supply grid and put into a ratio R relative to one another. The presence of asymmetrical vibrations is indicated if the ratio R exceeds a specified threshold.

A control system for a multi-phase power system includes a first phase line, a second phase line, and a third phase line. The control system includes a plurality of regulator controls including a first regulator control configured to control a first tap changer associated with the first phase line, a second regulator control configured to control a second tap changer associated with the second phase line, a third regulator control configured to control a third tap changer associated with the third phase line, and an electronic processor coupled to the first regulator control, the second regulator control, and the third regulator control. The electronic processor is configured to regulate the voltage of the multi-phase system using the first, second, and third regulator controls.

A device determines a first current, of a first input phase of a power system, and a second current, of a second input phase of the power system. The device determines whether the first input phase and the second input phase are balanced based on the first current and the second current. When the first input phase and the second input phase are not balanced, the device selects the first input phase and an output phase of the power system. The device balances the first input phase and the second input phase by using the first input phase and the output phase.