Abstract: A hybrid on-load tap changer, for use in high voltage alternating current power transmission, including a selector and a diverter having two legs defining respective current paths. Each leg includes a pair of opposed first and second semiconductor switches. The hybrid on-load tap changer also includes a controller configured to switch on one of the first or second semiconductor switches of a given leg at a predetermined point within the alternating current cycle so as to commutate off a desired semiconductor switch in the other leg.

Abstract: An arrangement and a method for reactive power compensation in connection with a power transmission line. The arrangement includes at least one transformer and at least one reactive power compensator connected to the low-voltage side of the transformer and at least one adapter reactor, the adapter reactor being connected in series with the transformer so that the reactive power compensator is connected to the power transmission line via the transformer and the adapter reactor.

Abstract: Aspects of a multi-level electrical distribution control system associated with an electrical distribution grid are disclosed. Data access and processing across the multi-level control system and the electrical distribution grid can provide improved utilization of energy within the electrical distribution grid. Further, dynamic reconfiguration of the electric distribution grid can be based distributed processing and access to information relating to the electrical distribution control system or electrical distribution grid. An encapsulated DNNC data element is disclosed as an efficient and secure means of accessing data across the multi-level electrical distribution control system or the associated electrical distribution grid.

Abstract: The subject specification comprises enhanced power system balance control for a multi-tier hierarchical electrical distribution network (EDN). The EDN comprises a specified number of distribution network node controller (DNNC) components employed to desirably control power system balance, data communications, and power distribution between respective tiers of the EDN to facilitate efficient power distribution. In each tier, a power system balance component (PSBC), associated with a DNNC component, can monitor power system balance, such as load phase balance, associated with multi-phase power distribution for its tier, and detect power system imbalances in that tier. A power balance correction action can be identified and executed (e.g., automatically) in response to the detected power system imbalance to rectify the imbalance, wherein the correction action can include dynamic switching of loads between phases and/or filtering of the power signal.

Abstract: Aspects of a multi-level electrical distribution control system associated with an electrical distribution grid are disclosed. A multi-level control system provides a non-flat topography for electrical distribution grid control. A hierarchical structure can be employed in the topography of the control system. Further, tree and mesh network structure, among others, can be employed in the topography of the control system. These rich topographies can provide for closed loop control at each level of the control system, improved reliability of the control system through redundant topographical network structures, and desirable data handling features that can reduce data congestion and computing costs by distributing data handling, processing, and control across the levels of the control system.

Abstract: Aspects of a multi-level electrical distribution control system associated with an electrical distribution grid are disclosed. Coordination between the multi-level control system, the electrical distribution grid and an electrical transmission system can provide improved utilization of energy within the electrical distribution grid. Further, dynamic reconfiguration of the electric distribution grid can improve reliability of the electric distribution grid and can provide additional energy utilization pathways to reduce demand on the electrical transmission system. Moreover, improved control of the topography and energy utilization of the electrical distribution grid can improve forecasting for development of the electrical transmission system.

Abstract: The subject specification comprises enhanced communication infrastructure for a multi-tier hierarchical smart distribution grid (SDG). The SDG comprises a specified number of distribution network node controller (DNNC) components employed to desirably control communications and power distribution between respective tiers of the SDG to facilitate efficient power distribution. When communication between the a DNNC in one tier and another DNNC in another tier, is desired, the DNNC can identify available communication channels and respective communication conditions of the available communication channels, and can dynamically select a subset of available data and preferred communication channel, based at least in part on predefined control criteria, to control data transmission loads in the network and facilitate real time control of the SDG. Data can be communicated via the selected communication channel.

Abstract: The invention relates to an arrangement and a method for switching an inductive load. Yet further the invention relates to a software product of a control system switching an inductive load. A semiconductor valve is used for switching an inductive load. The semiconductor valve comprises at least two semiconductor levels. A firing signal is supplied to the semiconductor valve. There is a determined delay between the firing signals of at least two semiconductor levels.

Abstract: A master-slave current sensor system for measuring, for example, differential current on a transmission line is described. The slave current sensor can be periodically recalibrated (or have a compensation value re-calculated) based on the master sensor's average output, and the slave sensor can be unpowered and remote from an electronics box which receives its measurements. Health monitoring and fault location can also be performed using the master-slave optical current sensor system, optionally in conjunction with one or more voltage sensors.

Abstract: A device for measuring current and/or voltage in a high voltage wire can be provided in a folding insulator. The mechanically folding insulator device can include a plurality of insulated sections. Pairs of insulated sections are coupled together by a link which allows for mechanical folding of said insulator device. The insulated sections of the folding insulator device have a cavity formed therein which contains an optical fiber surrounded by an insulative material.

Abstract: A multilevel voltage source converter for high voltage DC power transmission and reactive power compensation. The voltage source converter includes at least one phase element including a plurality of semiconductor switches to interconnect a DC voltage and an AC voltage. The voltage source converter also includes at least one auxiliary converter to act as a waveform synthesizer to modify the DC voltage presented to the DC side of the phase element.

Abstract: The sensor comprises a cable (5) looped around an element to be monitored, and includes a winding (10) on the Rogowski principle. It is original in that it is open at its ends (6, 7), that is to say the winding (10) is flush with the end faces (25) of the cable (5), and perfect continuity of the winding and of measurement over a circumference is established by abutting the two ends together. This cable may have a temperature sensor and a memory in which the measurement characteristics of the sensor are held. The sensor is reliable and accurate, and it can be left permanently in an electrical apparatus, or replaced, with no difficulty.

Abstract: A series spark gap is triggered such that in parallel with partial spark gaps (1, 2) of the series spark gap there are coupled first voltage distribution means. Further, at least in one partial spark gap (1, 2) there is arranged an additional electrode (10) whose voltage is set to a given level by means of second voltage distribution means. The voltage level of the additional electrode (10) is changed by disturbing the voltage distribution of the second voltage distribution means. Thus the spark gap between the main electrode (6a, 6b) of the partial spark gap (1) and the additional electrode (10) will be ignited. Capacity of the second voltage distribution means is lower than that of the first voltage distribution means and consequently the voltage acting over the first voltage distribution means does not change significantly.

Abstract: A device and method of protecting a link in a medium, high, or very high voltage power network, with current and voltage transformers and trip circuits being disposed on the link. The protection device includes a mechanism to directly connect to a power supply, to the current and voltage transformers, and to the trip circuits, via analog links, and a mechanism to convert from analog to digital that is connected to a central processor unit via a digital link, the analog-digital conversion mechanism including an integrated test plug socket function.

Abstract: A method of controlling at least one voltage converter having a plurality of cells in series, comprising an AC part and a DC part, characterized in that the AC input voltage (Vei) of each cell is determined directly by the use of a high speed current control loop relating to the AC part and a lower speed voltage control loop relating to the cells, the method including choosing the following voltage control law: ? i = C i 2 ? ( 2 R pi ? C i ? Z i + ? ? t ? Z i ? ? _ ? ? ref - K 1 ? Zi - K 2 ? Zi ? sign ? ( E Zi ) ) where: K1zi and K2zi are positive adjustment gains; Ci is the continuous capacitance of the capacitor Ci of each cell; Rpi is the losses associated with each cell; Zi—ref is the reference value of Zi=(UDCi)2, UDCi; being the direct voltage across the capacitor Ci; and EZi is such that EZi=Zi?Zi—ref.

Abstract: The subject specification comprises a generalized grid security platform (GGSP) that can control power distribution and operations in a power transmission and distribution grid (PTDG) in real or near real time. The GGSP can receive data from one or more data sources, including a PMU(s) or an IED(s), which can obtain power system related data and provide at least a portion of such data to the GGSP at a subsecond rate. The GGSP can correlate data from the data sources based at least in part on a temporal, geographical, or topological axis. The GGSP can analyze the data, including performing predictive analysis, e.g., via simulation, root cause analysis, post mortem analysis, or complex event processing, when desired, to facilitate identifying a current or predicted future state of the PTDG, a cause or source of an abnormal condition, or a remedial action execution plan, new operation or maintenance guidance, etc.

Abstract: A method and an apparatus for dynamic signal switching with multiple measurement sources, for a merging unit in an electrical power system, said merging unit receiving at least two input signals from at least one current transformer measuring the same physical primary quantity. The method comprises a step of outputting from said merging unit, in a real-time mode, a digitized output stream of sampled values with the truest representation of the physical primary quantity, based on the actual values of the input signals.

Abstract: The method for detecting single-phase grounding fault based on the harmonic component of residual current is provided, in which collecting and calculating the phase differences of third harmonic waves relative to the fundamental wave of the residual current in the feeder line, and judging if the phase differences of the residual current in the feeder line is into a threshold range, and judging if there is a suspected grounding fault, and confirming the fault event by judging the duration and the generated times of the suspected grounding fault. Another method for detecting single-phase grounding fault based on the harmonic component of residual current is provided, in which the residual current of neutral point is used.