Patent classifications
H02H7/262
Circuit breaker failure protection in a power substation
A method for circuit breaker failure (CBF) protection in a power substation is disclosed. The power substation includes a first circuit breaker (CB), a second CB coupled to the first CB, a feeder coupled to the first CB and the second CB, a power plant coupled to the feeder, a first plurality of CBs coupled to the first CB, and a second plurality of CBs coupled to the second CB. The method includes sending a first stage tripping command to the first CB and the second CB to trip the first CB and the second CB responsive to a non-high current tripping command being active for a first period of time, and one of a current condition and an energization condition being satisfied for the first period of time, sending a first second-stage tripping command to the first plurality of CBs to trip the first plurality of CBs responsive to the non-high current tripping command being active for a second period of time, and one of the current condition and the energization condition being satisfied for the second period of time, and sending a second second-stage tripping command to the second plurality of CBs to trip the second plurality of CBs responsive to the non-high current tripping command being active for a third period of time, and one of the current condition and the energization condition being satisfied for the third period of time. The second period of time and the third period of time may be longer than the first period of time.
Direction-to-fault and zone-based distance-to-fault electric power sectionalizer systems
Electric power Fault detection, isolation and restoration (FDIR) systems using smart switches that autonomously coordinate operations to minimize the number of customers affected by outages and their durations, without relying on communications with a central controller or between the smart switch points. The smart switches typically operate during the substation breaker reclose cycles while the substation breakers are open, which enables the substation breakers to reclose successfully to restore service within their normal reclosing cycles. Alternatively, the smart switch may be timed to operate before the substation breakers trip to effectively remove the substation breakers from the fault isolation process. Both approaches allow the FDIR system to be installed with minimal reconfiguration of the substation protection scheme.
SAFETY POWER DISCONNECTION FOR POWER DISTRIBUTION OVER POWER CONDUCTORS TO RADIO COMMUNICATIONS CIRCUITS
Safety power disconnection for remote power distribution in power distribution systems is disclosed. The power distribution system includes one or more power distribution circuits each configured to remotely distribute power from a power source over current carrying power conductors to remote units to provide power for remote unit operations. A remote unit is configured to decouple power from the power conductors thereby disconnecting the load of the remote unit from the power distribution system. A current measurement circuit in the power distribution system measures current flowing on the power conductors and provides a current measurement to the controller circuit. The controller circuit is configured to disconnect the power source from the power conductors for safety reasons in response to detecting a current from the power source in excess of a threshold current level indicating a load.
High-impedance fault detection using wireless current transformers
The present disclosure pertains to systems and methods for monitoring and protecting an electric power system. In one embodiment, a system may comprise line-mounted wireless current transformers to measure at least one parameter of an alternating current (AC), receive a synchronization signal at which to measure the AC, and send a message comprising the measured AC. The system may also comprise an intelligent electronic device (IED) to send the synchronization signal to and receive the messages from the line-mount wireless current transformers, determine whether a high-impedance fault (HiZ) exists between the line-mounted wireless current transformers, and implement a control action based on the existence of the HiZ fault.
TIE SWITCH RESTORATION
A control system and method for a group of interconnected feeders which enables fault location, isolation and service restoration without requiring each switch to have topology knowledge of devices in adjacent feeders. The method defines, for each switch, connectivity and X/Y directional information about its neighboring switches and propagates this information throughout each feeder. A leader device is also determined for each feeder. Information about topology of adjacent feeders is not needed by all devices. Only normally-open tie switches which define a boundary between two adjacent feeders have knowledge of the devices in both feeders. Switches which open during fault isolation automatically find open tie switches in a direction opposite the fault, and request service restoration downstream of the fault by providing power from an adjacent feeder. Leader devices ensure an overload condition is not created before initiating opening and closing operations of switches downstream of the fault.
Systems and methods for protecting against fault currents
Adaptive protection methods and systems for protecting agains) extreme fault currents in a power system are provided. Communication capabilities and protocols defined in IEC 61850 can be used to provide smart cascading switching actions for removing the fault from the power system. A supervisory protection algorithm can be used, and the protection can be activated if the fault current is higher than a breaking capacity of the circuit breakers of the power system.
Autonomous electric power fault detection, isolation and restoration systems
Fault detection, isolation and restoration systems for electric power systems using smart switch points that autonomously coordinate operations to minimize the number of customers affected by outages and their durations, without relying on communications with a central controller or between the smart switch points. Each smart recloser can be individually programmed to operate as a tie-switch, a Type-A (normal or default type) sectionalizer, or a Type-B (special type) sectionalizer. The Type-A recloser automatically opens when it detects a fault, uses a direction-to-fault and zone-based distance-to-fault operating protocol, and stays as is with no automatic opening when power (voltage) is lost on both sides of the switch. The Type-B sectionalizer does the same thing and is further configured to automatically open when it detects that it is deenergized on both sides for a pre-defined time period, and to operate like a tie-switch once open.
Circuit implementing an AC smart fuse for a power distribution unit
A circuit comprises an output connector connectable to a load. A relay selectively connects the output connector to an AC power source. The relay is responsive to a disabling signal to disconnect the output connector from the AC power source. A sensor senses a level of power delivered to the load via the output connector. A detector emits a first fault signal when the sensed power level exceeds a fixed power limit. A latch maintains the first fault signal until it receives a rearm signal. A controller emits a second fault signal when the sensed power level exceeds a configurable power threshold, receives a user command to rearm the circuit, and in response to receiving the user command, emits the rearm signal and ceases the emission of the second fault signal. A logic combiner generates the disabling signal when it receives one of the first and second fault signals.
METHOD FOR CONTROLLING THE RESTORATION OF A NETWORK
A method for controlling the rebuilding of an electrical supply network, wherein the electrical supply network has a first network section and at least one further network section, at least one wind farm is connected to the first network section, the wind farm can be controlled via a wind farm control room, the first network section is coupled to the at least one further network section via at least one switching device in order to transmit electrical energy between the network sections, the at least one switching device is set up to disconnect the first network section from the at least one further network section in the event of a fault, a network control station is provided for the purpose of controlling the at least one switching device, wherein, in the event of a fault during which a network fault acting on the first network section occurs, the first network section is disconnected from the at least one further network section by the at least one switching device, the wind farm control room interchanges data with the network control station via a control room connection, wherein the control room connection is a failsafe communication connection between the wind farm control room and the network control station and can be operated independently of the electrical supply network, in particular can be operated even in the case of the fault in the first network section, and the wind farm receives data from the network control station via a wind farm connection, wherein the wind farm connection is a failsafe communication connection between the wind farm and the network control station and can be operated independently of the electrical supply network, in particular can be operated even in the case of the fault in the first network section, and further data which are not transmitted via the control room connection and are not transmitted via the wind farm connection are transmitted via a further data connection provided that the latter has not failed.
PROTECTION ASSISTANCE DEVICE OF MULTIPLE CIRCUIT BREAKERS IN LOW-VOLTAGE SYSTEM
The present disclosure provides a protection assistance device of multiple circuit breakers in a low-voltage system, in which protection assistance in both directions from the upper side to the lower side or from the lower side to the upper side is possible, and the number of wires for protection assistance between multiple upper/lower circuit breakers can be minimized. The protection assistance device includes at least one upper low-voltage circuit breaker; at least one middle low-voltage circuit breaker; at least one lower low-voltage circuit breaker; and a communication line which makes a communication connection between the low-voltage circuit breakers, wherein the low-voltage circuit breakers comprise a control unit for, when a trip operation of automatically breaking a circuit is performed, transmitting a communication packet for reporting a trip operation state to at least one predetermined circuit breaker among the circuit breakers through the communication line.