A controller of a power supply system includes a memory configured to store a self-inductance and a mutual inductance of two reactors included in a boost converter; and a processor configured to determine a present operating state of the boost converter, based on a ratio of an input voltage into the boost converter to an output voltage therefrom, a duty ratio applied to switching elements of the boost converter, the self-inductance, and the mutual inductance, the present operating state being one of operating states among which the waveform of a reactor current differs; and measure an average of the reactor current in a predetermined switching period of the switching elements, based on the input voltage, the output voltage, and the duty ratio, in accordance with the waveform of the reactor current corresponding to the present operating state of the boost converter.

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.

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.

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.

The present disclosure pertains to systems and methods for detecting traveling waves in electric power delivery systems. In one embodiment, a system comprises a capacitance-coupled voltage transformer (CCVT) in electrical communication with the electric power delivery system, the CCVT comprising a stack of capacitors and an electrical contact to a first ground connection. Electrical signals from accessible portions of the CCVT are used to detect traveling waves. Current and/or voltage signals may be used. In various embodiments, a single current may be used. The traveling waves may be used to detect a fault on the electric power delivery system.

A passive, current dependent inductivity (1) comprises a magnetic core (2), windings (3) and at least one bank air gap (4). A saturation region (5) made of magnetic material is arranged between the bank air gap (4) and the windings (3). A magnetic flux path (6) bifurcates into a first path (61) passing through the saturation region (5) and into a second path (62) passing through the bank air gap (4) and bypassing the saturation region (5). The magnetic resistance of the first path (61) is lower than the magnetic resistance of the second path (62) for winding currents below a first saturation current (7a) and whereby the magnetic resistance of the second path (62) is lower than the magnetic resistance of the first path (61) for winding currents above the first saturation current (7a) due to saturation of the saturation region.

A transformer arrangement comprises a primary winding and a secondary winding, which are magnetically coupled. The transformer arrangement also comprises a compensating arrangement, which is circuited to provide a link between a terminal of the primary winding and a terminal of the secondary winding. The compensating arrangement is configured such that a change of a magnetic flux through the primary winding and the secondary winding induces a voltage in the compensating arrangement. The compensating arrangement comprises at least one coupling capacitor configured to block a DC current and to pass a current caused by the induced voltage. The compensating arrangement is configured to at least partially compensate a current that is caused by an inter-winding capacitance between the primary winding and the secondary winding using the current caused by the induced voltage.

A detection error occurs due to ripple when a current transformer detects zero cross of current. Provided is a detection device for detecting zero cross of output current output from switching circuit including a first switching element and a second switching element connected in series, and the detection device has: an acquisition unit which acquires an observation value that is based on gate current or an observation value based on gate voltage of at least one switching element of the first switching element and the second switching element, during Miller period in which Miller capacitance between a drain and a gate is charged; and a detection unit which detects zero cross of output current flowing between (i) output terminal between first switching element and second switching element and (ii) a load connect to output terminal, based on observation value during Miller period.