A current sensing device according to the present invention may comprise: a substrate part which includes at least two base substrates stacked in one direction and through which a circuit passes in the one direction; a coil part which is formed on at least one of the base substrates and surrounds the circuit; and a core part which is disposed between the base substrates while being spaced apart from the coil part, and surrounds the circuit.

The current transformer system that is the present invention allows for surveillance of an electronic grid at electrical power generating stations, at individual operational substations and in electric power distribution for electric network and grid measurement, protection, and control ranging from very low currents to high current magnitudes. The reception and relay of information from the CT primary circuit is sensed and transmitted by a primary electronic circuitry, digitized, converted to a fiber optic mode, transmitted to a secondary electronic circuit, processed and converted to a digital output and transmitted to various monitoring and recording devices.

The current transformer system that is the present invention allows for surveillance of an electronic grid at electrical power generating stations, at individual operational substations and in electric power distribution for electric network and grid measurement, protection, and control ranging from very low currents to high current magnitudes. The reception and relay of information from the CT primary circuit is sensed and transmitted by a primary electronic circuitry, digitized, converted to a fiber optic mode, transmitted to a secondary electronic circuit, processed and converted to a digital output and transmitted to various monitoring and recording devices.

An exemplary embodiment provides a current sensor comprising a printed circuit board (PCB), a Rogowski coil, and a controller. The PCB can comprise an aperture configured to receive a conductor carrying an alternating electrical current. The Rogowski coil can be positioned on the PCB along a perimeter of the aperture. The controller can be in electrical communication with the Rogowski coil and configured to generate an output signal indicative of the alternating electric current carried by the conductor. The current sensor can be configured to measure the alternating electric current relative to a full scale at a resolution of 1000:1 and at an accuracy within 1%, wherein the full scale can range over 5000:1.

A current transformer includes first and second transformer assemblies that each respectively comprise first and second groups of stacked iron core components. A first interface and a second interface are defined at an end of the first transformer assembly. A third interface and a fourth interface are defined at an end of the second transformer assembly. At least one of the first interface and the second interface is detachably connected with at least one of the third interface and the fourth interface. When the first and second transformer assemblies are connected with each other, the first and second groups of iron core components are combined to form a plurality of closed ring-shaped iron cores, and coils are respectively wound on at least two closed ring-shaped iron cores. An enclosed area defined between the first and second transformer assemblies causes induced current to be generated in at least one coil.

An energy harvesting device (CTH) installed in an electrical distribution system (EDS) for powering ancillary electrical devices (AD) used in the distribution system. The device includes a first voltage regulator circuit (CC) configured to produce a voltage matched to a power curve of a current transformer (CT) to which the device is electrically coupled. The device also includes a second and separate voltage regulator circuit (SVR) which continuously operates to maximize the amount of electrical energy recovered from the current transformer.

In an embodiment, a current sensor unit includes: a rectification module, to convert an AC current to a pulsed DC current; a conversion module containing an energy storage element, to store energy based upon the pulsed DC current during a charging mode and to generate a power supply current based upon a voltage of the energy storage element; a mode switching module, bypassed by the conversion module during operation in the charging mode, and bypassing the conversion module during operation in an energy release mode; a current sensor module, to detect a pulsed DC current flowing back from the conversion module or mode switching module; a control module, to acquire electrical energy from the power supply current, determine that operation is in the charging mode or energy release mode based upon the voltage of the energy storage element, and acquire a detection value provided by the current sensor module.

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.

A current transformer (CT) for the purpose of, for example, current measurement, that uses a power line as a first coil and a second coil for measurement purposes, is further equipped with a third coil. Circuitry connected to the third coil is adapted to measure a signal therefrom. The measured signal from the third coil is compared to a signal measured from the second coil and based on the results, internal CT parameters are determined allowing calibration of actual results to expected results thereby providing an improved accuracy. This is especially desirable when using the CT for measurement of the like of current or phase of the primary coil when measurements are adjusted using the newly determined calibration parameters.

A current transformer (CT) for the purpose of, for example, current measurement, that uses a power line as a first coil and a second coil for measurement purposes, is further equipped with a third coil. Circuitry connected to the third coil is adapted to inject a known reference signal to the third coil of the CT. The injected reference signal, i.e., current, generates signals in the first and second coils of the CT. The signal generated in the second coil is compared using circuitry attached thereto to the reference signal. Based on the results, and the difference between the expected results and the actual results, updated calibration parameters are determined. These provide improved accuracy when using the CT, for example for measurement of the like of current or phase of the primary coil when measurements are adjusted using the newly determined calibration parameters.