Patent classifications
H02H1/063
System and method of improving linearity of current sensor for a circuit interrupter
A circuit interrupter includes separable contacts; an operating mechanism; an electronic trip unit; and a current sensor assembly including: a harvester circuit having a primary conductor through which input current passes, a secondary winding and a harvester core structured to saturate at a first input current level, a Rogowski coil structured to measure voltage at an output of the Rogowski coil, the measured voltage indicative of output current of the Rogowski coil, where linearity of the output of Rogowski coil deviates more than a deviation tolerance based at least in part on saturation of the harvester core at the first input current level, and a compensation coil arranged at 180 degree opposite to the secondary winding of the harvester core, the compensation coil structured to delay saturation of the harvester core until the input current reaches a second input current level higher than the first input current level.
Fast ground fault circuit protection
A power converter with ground fault protection (PCGFP) circuit includes an input stage, a first voltage converter, and an output stage. The input stage is connected to a power bus to receive an input direct current (DC) voltage. The first voltage converter converts the input DC voltage to a second voltage and switches between an open and closed state to regulate power present on the power bus. The output stage includes a second voltage converter circuit to generate an output voltage having a different voltage level from the input DC voltage. A controller controls operation of the first and second voltage converters and is also capable of detecting a ground fault on the power bus. The controller operates the first and second voltage converts in a fault isolation mode in response to detecting the ground fault such that the first and second voltage converters isolate the ground fault.
Energy harvesting from fault currents
Methods and systems for protecting one or more flexible alternating current transmission system (FACTS) devices in a high voltage (HV) power transmission line are disclosed. The system may include a circuit breaker to de-energize the HV power transmission line when a fault current is detected on the HV power transmission line, and to determine whether the fault current has cleared. The system may further include a power supply to harvest energy from the fault current. The system may further include a bypass switch coupled to protect the FACTS devices by providing a controllable conduction path around the FACTS devices when the bypass switch is activated. And the system may further include a fault current harvesting circuit (FHC) and an actuator operating in conjunction to control the bypass switch based on the harvested energy.
Hybrid switch assembly and circuit interrupter including the same
A hybrid switch assembly for use in a circuit interrupter, the hybrid switch assembly including an input, an output, separable contacts electrically connected between the input and the output, a solid state switching circuit electrically connected between the input and the output and in parallel with the separable contacts, and a fuse electrically connected in series with the solid state switching circuit. The solid state switching circuit is structured to turn on and allow current to flow through it between the input and the output for a predetermined amount of time after the separable contacts separate.
Power relay system with arc flash incident energy reduction
One example includes a power relay system. The system includes a circuit breaker configured, when triggered, to provide an open circuit in a power line configured to conduct a current between a power grid point-of-interconnect (POI) and a power generator system. The system also includes a power controller configured to monitor the current and to generate a dynamic current threshold based on the current, the power controller being further configured to compare the current with the dynamic current threshold and to trigger the circuit breaker based on a difference of the current relative to the dynamic current threshold to set an arc flash incident energy level of the power generator system to less than or equal to a predetermined safety level.
ELECTROSTATIC PREVENTION CIRCUIT, ARRAY SUBSTRATE AND DISPLAY DEVICE
An electrostatic prevention circuit, an array substrate and a display device are provided. The electrostatic prevention circuit includes an electrostatic prevention sub-circuit, and the electrostatic prevention sub-circuit includes a thin film transistor and a capacitor; a gate electrode of the thin film transistor is connected to the capacitor, and the thin film transistor is controlled by a signal passing through the capacitor.
FAST GROUND FAULT CIRCUIT PROTECTION
A power converter with ground fault protection (PCGFP) circuit includes an input stage, a first voltage converter, and an output stage. The input stage is connected to a power bus to receive an input direct current (DC) voltage. The first voltage converter converts the input DC voltage to a second voltage and switches between an open and closed state to regulate power present on the power bus. The output stage includes a second voltage converter circuit to generate an output voltage having a different voltage level from the input DC voltage. A controller controls operation of the first and second voltage converters and is also capable of detecting a ground fault on the power bus. The controller operates the first and second voltage converts in a fault isolation mode in response to detecting the ground fault such that the first and second voltage converters isolate the ground fault.
HYBRID SWITCH ASSEMBLY AND CIRCUIT INTERRUPTER INCLUDING THE SAME
A hybrid switch assembly for use in a circuit interrupter, the hybrid switch assembly including an input, an output, separable contacts electrically connected between the input and the output, a solid state switching circuit electrically connected between the input and the output and in parallel with the separable contacts, and a fuse electrically connected in series with the solid state switching circuit. The solid state switching circuit is structured to turn on and allow current to flow through it between the input and the output for a predetermined amount of time after the separable contacts separate.
Method For Remotely Monitoring Failed Surge Arrester Disconnectors and Energy Harvester For Autonomous Power Supply Of Monitoring Devices Installed On Surge Arresters
A method of remotely monitoring a status of a surge arrester disconnector includes providing a long-range wireless mesh communication system including a plurality of disconnectors organized in a plurality of clusters. Each cluster includes a plurality of disconnectors that are physically located within a same cluster area. At least one of the disconnectors in each cluster is coupled to a communication device of a predetermined communication range. The method includes transmitting, from a first cluster, a status signal indicative of a status of a first disconnector in the first cluster to a second cluster located within the predetermined communication range, and consecutively transmitting the status signal from the second cluster to a third cluster within the predetermined communication range, until reaching an end cluster. The method includes transmitting, from the end cluster, the status signal to a monitoring station, and monitoring the status of the first disconnector at the monitoring station based on a result of transmission of the status signal.
Method of detecting electrical disturbance by DC component
The present disclosure relates a method of detecting an electrical disturbance by a DC component in a digital protective relay, which includes acquiring a sample value by sampling an input signal at a regular cycle, detecting the electrical disturbance based on a difference between a sampled first sample value and a second sample value after the first sample value, and when the electrical disturbance is detected, detecting the DC component based on a difference between the second sample value and a third sample value after the second sample value and a difference between the third sample value and a fourth sample value after the third sample value.