4818 results about "Potential transformer" patented technology

The present invention provides a universal serial bus (USB) voltage transformer, which comprises a main body, a transformer circuit unit, and several connectors. The transformer circuit unit is disposed in or at the inside of the main body. The connectors are electrically connected to the transformer circuit unit directly or via a connection cable. A USB voltage transformer having travel charging function is thus formed. The USB voltage transformer of the present invention can simultaneously charge several portable electronic devices like mobile phones, personal digital assistants, electronic translators, and small cameras.

A meter device for measuring electrical energy is provided. The meter device includes circuitry for measuring at least one parameter of electrical energy provided to the meter device. A storage device is provided for storing at least one calibration factor for compensating for errors associated with at least one of at least one current transformer (CT) and at least one potential transformer (PT) that operates on the electrical energy provided to the meter device. At least one processor is provided for processing the at least one calibration factor for adjusting the measuring for compensating for the errors when measuring the electrical energy.

System for monitoring oil level and detecting leaks in power transformers, reactors, current and potential transformers, high voltage bushings and the like, notably for a system that through the use of sensors and other electronic components measures and monitors transformers and similar equipment in real time, filled with insulating oil, with greater precision and without need for floats or mobile mechanical parts, while presenting countless facilities in the sense of making level monitoring more reliable and safer, highlighting the level error calculations, oil leak detection alarm, excess oil detection alarm during the equipment filling process and calculation of tendencies of evolution for levels among other facilities.

A comprehensive detecting and analyzing platform for performance of digital electric energy metering systems of intelligent transformer substations is provided with a detecting system and a background expert system. The detecting system comprises an electronic transformer detecting system, a digital/digital-value-input electric energy meter detecting system and a digital electric energy metering comprehensive performance detecting system. By the background expert system, real-time monitoring and value tracing can be simultaneously carried out for electronic/optical current transformers, electronic voltage transformers, digital/digital-value-input electric energy meters and the like, and electric energy data of analog systems and multiple digital systems can be compared and analyzed so that the comprehensive performance of each digital electric energy metering system is detected. Detection results are comprehensive owing to multiple signal acquisition channels and comprehensive consideration on metering risk points of the systems, and the comprehensive detecting and analyzing platform is beneficial to improving metering accuracy for the intelligent transformer substations and digital transformer substations, and provides a good technical support for constructing the intelligent transformer substations and the digital transformer substations.

A metal clad switchgear assembly comprising multiple compartments defined within an electrical enclosure is provided. The compartments interchangeably accommodate electrical components, for example, current transformers, a circuit breaker, a control power transformer, an epoxy encapsulated potential transformer, etc., electrical cables, and bus bars in predetermined positions for allowing front access and/or rear access to them. One or more compartments are configured for enabling the electrical cables to enter into and/or exit out from the electrical enclosure for allowing front and/or rear access to the electrical cables. A mounting block assembly is positioned in one or more of the compartments for mounting, enclosing, and providing front access to the electrical components. One or more infrared windows and inspection windows are positioned on a front side and/or a rear side of the switchgear assembly for scanning and providing a visual indication of the electrical components, the electrical cables, and the bus bars.

A soft-load power distribution system includes a transfer switch having a first input to a utility power source with a utility alternating current (AC) voltage, a second input to a generator power source with a generator AC voltage, and an output to a load. A first switch is electrically connected between the first input and the output and a second switch is electrically connected between the second input and the output. The transfer switch has a third input, such as a go to emergency input, controlling the first and second switches. A bypass switch is electrically connected between the second input and the output. First and second sensors, such as potential transformers, sense the utility and generator AC voltages, respectively. A controller closes the bypass switch when the utility AC voltage is within a predetermined range of the generator AC voltage, and includes an output controlling the third input.

A power converting system has power converters for converting a direct current into an alternating current, a DC power source arranged on the DC side of the power converters, and voltage dividing transformers having windings whose first ends are connected to the power converters phase by phase and whose second ends are joined together and connected to a load phase by phase. Also provided is a controller for controlling the power converting system.

A power measuring apparatus including a voltage transformer, a voltage-current measuring circuit, and an operation unit is provided. The voltage transformer converts an input voltage signal into an output voltage signal. The voltage-current measuring circuit includes an inductor, a first resistor, a first capacitor and a second capacitor. A first end of the first inductor herein receives the output voltage signal and a second end thereof generates a voltage feedback signal. The operation unit performs an operation on the voltage feedback signal and a terminal current signal between the first terminal and the second terminal of the first capacitor so as to calculate a power signal. In this way, the accuracy of thermal test is effectively increased by the presented invention.

A sectionalizing and location method of the small current grounding fault of the power system relates to the detecting field of the grounding fault of the power system. The invention is characterized in that the maximum correlation coefficient of two transient zero sequence current signals after filtration is calculated, the related information of the transient zero sequence current between two neighboring detecting points caused by faults is utilized as the basis of the fault sectionalizing and the voltage transformer does not need to be assembled, the fault section is determined according to the maximum correlation coefficient of the transient zero sequence current of the neighboring detecting points. The method has the advantages of the higher amplitude of the transient signal than that of the stationary signal and easy detection, no influence from the grounding mode of the neutral points of the system, occurrence of the transient process during each breakdown of the insulation at the flashing failure and more rich transient signal and wide application, only need of the current signal, and no need of the voltage transformer on the detecting points.

The present invention relates to the relay protection method in the field of a power system. The present invention discloses a method for realizing two-terminal fault location in the power system through two terminal synchronism sampling current and voltage according to the method of equal voltages at two ends of a fault point and using a phase current and a phase voltage without zero sequence current and zero sequence voltage. The method comprises main steps as follows: a line protection device samples to a line side current sensor secondary current and voltage sensor secondary voltage to obtain a corresponding instantaneous value of the current and the voltage. The Fourier form of a three phase current and a three phase voltage on the side is worked out using a Fourier algorithm. The phasor form of phase current and phase voltage obtained by filtering to compute of protecting synchronism sampling on the other side is received through optical fiber network of communication. The distance from the protection arranging place to the fault point is obtained using the situation that the phase voltages on two sides of the fault point is equal with each other. The method is not affected by the power supply impedance and the transition resistance in the line operation method. Theory and practice prove that the method greatly improves the accuracy of transmission line fault location.

The invention discloses an intelligent dynamic power distribution network neutral-point grounding method and a complete device. The complete device comprises a grounding transformer (1), an arc suppression loop switch (2), a resistance loop switch (3), an adjustable reactor (4), a damping resistor (5), a damping resistor short-circuit switch (6), a resistor (7), a neutral-point voltage transformer (8) and a computer testing and control system (9). The intelligent dynamic power distribution network neutral-point grounding method and the complete device is technically characterized in that a power distribution network neutral-point grounding mode is dynamically converted from an arc suppression coil grounding mode into a small-resistance grounding mode. When the device is connected to a power grid or a power grid operation mode changes, the device firstly works in the arc suppression coil grounding mode. The device measures capacitive current, adjusts inductive current and enables IL-IC to be smaller than or equal to I delta, wherein the I delta is a preset residual current control value. When a single-phase grounding fault of the power grid occurs, the device outputs the inductive current to perform compensation and arc suppression to grounding fault current. If the fault is an instantaneous fault, the fault is eliminated through the compensation and the arc suppression. If the fault is a permanent fault and the grounding fault is still not eliminated after certain time T, the arc suppression coil grounding is converted into the resistance grounding mode, and a fault line is judged and disconnected by detecting zero-sequence current of feeder lines.

The present invention provides a reliable modular production quality excimer laser capable of producing 10 mJ laser pulses in the range of 1000 Hz to 2000 Hz or greater. Replaceable modules include a laser chamber; a pulse power system comprised of three modules; an optical resonator comprised of a line narrowing module and an output coupler module; a wavemeter module, an electrical control module, a cooling water module and a gas control module. Important improvements have been provided in the pulse power unit to produce faster rise time and improved pulse energy control. These improvements include an increased capacity high voltage power supply with a voltage bleed-down circuit for precise voltage trimming, an improved communication module that generates a high voltage pulse from the capacitors charged by the high voltage power supply and amplifies the pulse voltage 23 times with a very fast voltage transformer having a secondary winding consisting of a single four-segment stainless steel rod. A novel design for the compression head saturable inductor greatly reduces the quantity of transformer oil required and virtually eliminates the possibility of oil leakage which in the past has posed a hazard.

Bender devices are demonstrated by developing non-uniform fields within a homogeneous, non-planar single slab active member material of non-uniform thickness through geometrical constraints and electrode placement. Single slab actuators are demonstrated for semiconductor designs including MEMS applications. Single slab bender periodic designs are demonstrated to be well suited for MEMS fabrication. Shaped actuators having a topological pattern formed across at least one portion are demonstrated to induced strain at the patterned portion of the actuator, causing the patterned portion to flare into open and close positions upon application of an external field. Voltage transformers, spark generators, power sources, and sensors are developed using the non-planar, homogeneous, single slab active member material of non-uniform thickness. Last, semiconductor process design techniques are demonstrated for periodic and other non-planar single slab actuators.

A method for selecting wire of single phase earthing in neutral point noneffective earthing system includes making instant short circuit between neutral point and ground at position near two ends voltage polarity from positive to negative over zero by short circuiter set between neutral point and ground when single phase earthing is occurred in neutral point noneffective earthing system and state is stabilized in order to generate a short circuit pulse current being used to judge earthing line through short circuit detector. The device for realizing said method is also disclosed.

The invention discloses an output power-based diagnosis method for an open-circuit fault of an insulated gate bipolar transistor (IGBT) of a three-phase inverter. The method comprises the following steps of: A, respectively measuring three-phase voltages and three-phase currents by using a potential transformer (PT) and a current transformer (CT) installed on the output phase in the inverter, and respectively calculating the half-wave power corresponding to six half-wave currents of the three phases of the current period; and B, comparing the six half-wave power values with a set open-circuit fault power threshold value P0, if one or two half-wave power values are less than the set open-circuit fault power threshold value P0, judging that the corresponding IGBT causes an open-circuit fault; or if three half-wave power values are less than the set open-circuit fault power threshold value P0, judging that the IGBTs corresponding to the two half-wave power values on the same side cause the open-circuit fault. By the method, any one or two IGBTs which cause the open-circuit fault can be detected and positioned, so that a controller of the inverter can take a tolerance strategy and reduce waveform distortion conveniently; the inverter can be maintained in time; and the loss enlargement and accidents are avoided effectively.

“SYSTEM AND METHOD FOR MONITORING DISSOLVED GASES IN INSULATING OIL OF POWER TRANSFORMERS, REACTORS, ON-LOAD TAP CHANGERS, CURRENT TRANSFORMERS, POTENTIAL TRANSFORMERS, CONDENSIVE BUSHINGS AS WELL AS SIMILAR HIGH VOLTAGE EQUIPMENTS IMMERSED IN OIL”, remarkably consisting of a system that couples to an orifice for the insulating oil accessing, assuring to the monitoring system the access to an oil sampling with a good representativity of what is going on inside the high voltage equipment, besides allowing a simple and safe installation, and also presenting to the user several resources and interfaces.

A power distribution network fault positioning method belong to the power generation and power network technology field, comprises: installing parallel connected middle resistors, vacuum contactor, monitoring terminal, voltage transformer and zero sequence current transformer; when a permanent earth fault occurs in the power distribution network, switching the middle resistors within a preset time; the monitoring terminals in the transformer station, switching station and distribution substation uploading the node voltage values before and after switching the parallel connected middle resistors and the zero sequence currents on the outer wires to the fault positioning monitoring platform; positioning by the fault determination method, and displaying the fault position points in the dynamic topology map of the power distribution network system. The invention avoids the deficiencies of current fault positioning products when applied in small current grounding system, causes the fault determination more intelligent and more accurate, is an ideal fault positioning method for small current grounding system.

The invention discloses a testing device for a low-voltage integrated metering system based on electric energy meter module and relates to product quality testing equipment for a low-voltage integrated metering system. The testing device of the invention comprises a concentrator (9), a collector (10), a triphase meter (11) and a single-phase meter (12) in a low-voltage integrated metering system; a PC machine (1), a digital signal source (2), a voltage powder amplifier (3), a current powder amplifier (4), a communication and verification switching circuit (5), a voltage switching circuit (6), an isolation-used current transformer switching circuit (7), an isolation-used voltage transformer switching circuit (8), and an external power supply (13). The invention adopts virtual electric energy meter technique to generate required electric energy meter history data, so as to remarkably shorten the testing time and improve the testing efficiency and performs integrated testing of the function and performance of the concentrator, the collector, the user electric energy meter and other equipment, resulting in a high cost performance. Therefore, the invention has extensive application prospects.

The invention relates to a device and a method for capacitor bank protection and state monitoring. The device consists of a capacitor bank, a breaker, a voltage mutual inductor, a current mutual inductor and a controller, wherein the controller controls the switching on/off of the breaker according to signals of the mutual inductors. The method comprises the following steps: calculating condensance change rate according to the condensance value of a fault phase of the capacitor bank and a rated condensance value, and taking the condensance change rate as a protection setting value; calculating the power-frequency condensance value of each phase of the capacitor bank according to the end voltage and current power-frequency effective value of each phase of the capacitor bank detected in real time; before the switching of the capacitor bank, inputting the original measured value and protection setting value of each phase in a protective device; after the switching of the capacitor bank, calculating real-time condensance change rate according to condensance monitored in real time and an original value; and finally, comparing the real-time condensance change rate and the protection setting value, and switching off the breaker when meeting the conditions so as to switch off a fault capacitor bank. The device is sensitive and reliable and is free from the influences of external factors such as capacitor imbalance, asymmetrical balance of a three-phase power supply, operating characteristic deviation between sensors and harmonic of a power system.

Wherein, with embed-meter method, applying split-core current transformer (PT) and split-core current transformer (CT) with same wire number as the tower ground wire to clamp all tower ground wires; or applying strip-shape PT and CT to enclose whole tower; filtering and analyzing the measured data to obtain the real and imaginary parts of fundamental wave component of voltage and current signals; calculating with special voltage-drop algorithm to obtain the target resistance. This invention improves efficiency, and reduces cost.