1324 results about "High voltage transformer" patented technology

An electrical power system for a cold cathode tube includes a high-voltage transformer with a primary side connected to a power supply and a secondary side connected to a cold cathode tube and includes a ground fault detector. The ground fault detector includes a resistive path, a detection circuit, an isolation circuit, and a stop latch. The resistive path is connected to the secondary side of the high-voltage transformer and is arranged to provide a ground fault path to ground fault current. The detection circuit is connected to the resistive path and is constructed and arranged to provide an output representing a fault detection signal. The isolation circuit is connected to the detection circuit and is constructed and arranged to isolate the fault detection signal from the primary side of the high voltage transformer. The stop latch has an input connected to the isolation circuit and an output connected to the power supply and is constructed and arranged to generate an inhibition signal for inhibiting operation of the power supply.

A plasma source for generating nonlinear, wide-band, periodic, directed, elastic oscillations in a fluid medium. The plasma source includes a plasma emitter having two electrodes defining a gap, a delivery device for introducing a metal conductor into the gap, and a high voltage transformer for powering the plasma emitter. A system and method for stimulating wells, deposits, and boreholes through controlled periodic oscillations generated using the plasma source. The system includes the plasma source, a ground control unit, and a support cable. In the method, the plasma source is submerged in the fluid medium of a well, deposit, or borehole and is used to create a metallic plasma in the gap. The metallic plasma emits a pressure pulse and shockwaves, which are directed into the fluid medium. Nonlinear, wide-band, periodic and elastic oscillations are generated in the fluid medium, including resonant oscillations by passage of the shockwaves.

A mosquito-killing LED lamp also serving as a lighting fixture includes an LED light source, one or a plurality of light board comprised of multiple UV LEDs and multiple visible light LED arranged in array; a power supply combined in modular with the LED light source to output power to drive those UV and visible light LEDs; and a casing containing the light board, one or a plurality of electric shock mesh holding against the light board, and one or a plurality of barrier on a surface of the casing; the power supply being electrically connected to one or a plurality of high voltage transformer, which in turn being electrically connected to the electric shock mesh to seduce and killing mosquitoes.

A semiconductor switch 12 connected in series with a smoothing capacitor 12 is constituted by connecting in parallel a diode 13D which permits to flow current regenerated from energy of electric charges stored in a high voltage capacitor 17 to a primary side of a high voltage transformer 15 for the smoothing capacitor 12 and switching means 13S which interrupts an output from the smoothing capacitor 12, and after turning off the switching means 13S, through alternative on and off control of switching means 161S˜164S the energy of electric charges stored in the high voltage capacitor 17 is regenerated to the smoothing capacitor 12 by making use of parasitic leakage inductance 15L. As a result, an X-ray high voltage device is provided which permits to drop a wave tail of a tube voltage in a high speed without complexing the structure of the high voltage part thereof.

The present invention refers to a DC/AC power inverter control unit of a resonant-type power converter circuit (400), in particular a DC/DC converter, for supplying an output power for use in, for example, a high-voltage generator circuitry of an X-ray radio-graphic imaging system, 3D rotational angiography device or X-ray computed tomography device of the fan-or cone-beam type. More particularly, the present invention is directed to a resonant-type power converter circuit out which comprises an interphase transformer (406) connected in series to at least one series resonant tank circuit (403a and 403a′ or 403b and 403b′) at the output of two DC/AC power inverter stages (402a+b) supplying a multi-primary winding high-voltage transformer (404), wherein said interphase transformer (406) serves for removing the difference (DI) in the resonant output currents (₁ and ₂) of the DC/AC power inverter stages (402a+b). Furthermore, the present invention is dedicated to a control method which assures that the interphase transformer (406) is not saturated. This control method ensures zero current operation and provides for that input power losses can be minimized.

The invention provides a method for preparing super- voltage transformer oil. It comprises following steps: making naphthenic base oil contact with hydrogenation treatment catalyst and hydrogenation refining catalyst in sequence under hydrogenation process condition; said hydrogenation treatment catalyst contains a thermal- resistant inorganic oxidant carrier and cobalt and/ or nickel, molybdenum and/ or tungsten and fluoride or phosphorus that loaded on said carrier, the total airspeed of said naphthenic base oil is 0.2- 1 h-1, and the relative airspeed of hydrogenation treatment catalyst is 0.3- 1.2 h-1, the relative airspeed of hydrogenation refining catalyst is 0.3- 2h-1.

A high voltage transformer for controlling inductance leakage used for a multiple lamp driving system includes at least one wire frame, a first winding, a second winding, a first magnetic unit, and a second magnetic unit. There is a receiving space in the wire frame for receiving the first magnetic unit, and a first region and a second region is formed on its surface. The first winding and the second winding are individually wound at the first region and the second region. The second magnetic unit is covered on the side of the wire frame. On an appropriate location of the bottom of the second magnetic unit, a transverse beam extends. Thereby, the transverse beam fully separates the low voltage magnetic flux path produced on the first magnetic unit by the first winding and the second winding and the high voltage magnetic flux path produced by the AC.

The invention relates to extra-high voltage transformer oil and a production process thereof. The extra-high voltage transformer oil comprises the following components in percentage by weight: 75wt%-85wt% of naphthenic-base base oil, 12wt%-22wt% of dodecyl benzene, 10ppm-200ppm of a metal de-activating agent and 0.1wt%-3wt% of a light stabilizer. Compared with the prior art, the extra-high voltage transformer oil is low in cost, simple in formula and production process, convenient to use, excellent in comprehensive performances and in particular suitable for being used as extra-high voltage transformer oil.

The invention discloses a network-side circuit of an electric locomotive unit, which comprises two network-side circuit bodies with pantographs. Each network-side circuit body consists of a high-voltage transformer, the pantograph, a high-voltage isolating switch, a main circuit breaker, a grounding switch, a lightning arrestor, a primary-side high-voltage current transformer, a transformer, a primary-side grounding current transformer and a shaft end grounding device. The high-voltage circuit of the electric locomotive unit further comprises a high-voltage circuit body without a pantograph, the high-voltage circuit consists of a main circuit breaker, a grounding switch, a lightning arrestor, a primary-side high-voltage current transformer, a transformer, a primary-side grounding current transformer and a shaft end grounding device. The three high-voltage circuit bodies are connected by roof high-voltage buses and high-voltage connecting cables. The network-side circuit of the electric locomotive unit can meet the requirement of heavy-load and high-power traction, an optional network-side high-voltage electric component can be isolated when breaking down, and power loss of an integral locomotive is minimized assuredly after fault isolation.

The invention relates to a modular multilevel converter (MMC)-based transformer-free four-quadrant high-voltage variable frequency power supply topological structure. A rectifier module and an inverter module have a modular multilevel structure and are formed by a plurality of subunits connected in series. The input side of the topological rectifier module is directly connected with a network-side high voltage through a charging circuit; the rectifier module converts a high-voltage alternating current (AC) voltage into a direct current (DC) voltage and inputs the DC voltage into the inverter module, and the inverter module converts the DC voltage into the AC voltage; and various states of a power system are simulated, and the topological structure has a four-quadrant type and can feed energy back. The topological structure has the advantages of removing the high-voltage transformer at the power input end, lowering cost, reducing volume and weight of a high-voltage variable frequency power supply, reducing consumption of components, and improving work efficiency, has a simple unit structure, and is convenient to wire and easy to disassemble and assemble.

A wind turbine comprises a nacelle, a generator and a high voltage transformer which are connected to each other and are located inside the nacelle. The wind turbine is provided with a low voltage power supply source which is located remotely from the high voltage transformer and comprises a low voltage transformer connected between the high voltage transformer and a power grid. The low voltage transformer is connected to the nacelle and provides it with low voltage power.

The invention discloses a Kalman filtering transformer fault prediction method based on a neural network. The Kalman filtering transformer fault prediction method comprises the following steps that monitoring data of a transformer are obtained; the monitoring data are subjected to segmentation processing according to time periods, and a data set of each time period is obtained; outlier points of the data sets are judged, the number of the outlier points is counted, the outlier points are converted into normal data values, and null points and ultra-range points in the data sets are removed to form new data sets; the new data sets are subjected to regression analysis, a model of performing regression analysis is established, and the monitoring data are predicted to obtain prediction trend results; and a fault diagnosis model is established, the prediction trend results are input to the fault diagnosis model to conduct fault diagnosis, and fault diagnosis prediction results are obtained.Possible future trends of the monitoring data can be predicted. Through establishment of the fault diagnosis model and a neural network model and through model prediction, diagnosis results of possible future faults of a high voltage transformer can be obtained.

Present invention relates to a spray type vapour-cooled transformer consisting of iron core, loop, oil tank, gaseous pump less self circulation cooling system and liquid circulatory system. Gaseous pump free self circulation cooling system is composed of wind bore, condensator and liquid return pipe, wherein wind bore upside connected with condensator, condensator bottom connected with liquid return pipe. Liquid spray circulatory system is composed of spray conduit, liquid guide plate and pump. Oil tank bottom is filled with liquid state heat-eliminating medium whose upper side is filled with insulation gaseous. For high-voltage transformer, oil tank bottom can hold resistor connected with standby heating power supply, or setting supercharging device outside the oil tank, or properly increasing initial predetermined insulation air pressure in transformer.

In an X-ray generating device of the neutral grounding system, to remove an unbalance voltage generated due to difference in impedance of parallel transformer coils of the high voltage transformer and particularly an unbalance voltage involved with difference in impedance above and below the neutral points generated in a metal X-ray tube, a plurality of currents flowing in opposite directions through primary windings of the parallel transformer coils in the high voltage transformer are passed through by or wound around a common toroidal coil or wound around an outer circumference of the toroidal coil at a predetermined ratio of winding number, and the unbalance voltage occurring to the secondary side is cancelled by changing primary current with magnetic behavior.

The invention provides a current and short-term reliability assessment method of a high-voltage transformer. According to the method, precise and quantized assessment is carried out on the current and short-term reliability of the high-voltage transformer by means of a fault tree and a fault mode assessment model through data obtained through all detection means of a current transformer, wherein the data include routine tour, special tour and preventive test data, diagnosis test data, foundation standing book information of equipment, past-year equipment defect and fault records and other data. After assessment, a mode that each maintainable component of the transformer can possibly have a fault and the fault generation probability can be obtained, and maintenance measures to reduce or prevent the fault mode can be formulated under guidance according to the correspondent relationship between the fault mode and inspection methods. A development trend of the short-term reliability can be predicted through an aging model of the equipment. The method can assess reliability of the high-voltage transformer, and has the advantages of being concise, easy to understand, precise, visual, quantized and the like.

The invention provides a method for braking a magnetizing inrush current in the differential protection of an ultra-high voltage transformer, which comprises the following steps: acquiring a corresponding magnetizing inrush current criterion of each phase by the weight of an amplitude bias current, the weight of a secondary harmonic current and a symmetry degree of the waveform of each phase; and braking the magnetizing inrush currents of the phases whose magnetizing inrush current criterions are greater than a magnetizing inrush current braking coefficient. The method provided by the invention comprehensively considers the sizes of the three parameters, i.e. the weight of the amplitude bias current, the weight of the secondary harmonic current and the symmetry degree of the waveform. The increase or decrease of only one of the parameters cannot determine whether the whole magnetizing inrush current criterion is greater than or less than the magnetizing inrush current braking coefficient so as to solve the defect of only utilizing the secondary harmonic as the magnetizing inrush current criterion in the prior art. The invention makes the braking of the magnetizing inrush current more reliable so as to have a more accurate tripping of the differential protection of the transformer without causing false tripping or refuse operation. The invention also provides a system for braking the magnetizing inrush current in the differential protection of the ultra-high voltage transformer.

The invention discloses a control method and power supply device for an electron-beam welding machine to accelerate high-voltage power supply, which uses three-phrase commercial power and adopts the current transformation mode of AC-DC-AC-DC; wherein, the inversion link DC-AC in the middle is medium-frequency inversion; the function of high frequency pulse width modulation and voltage regulation is realized in the inversion process; the transmission of the electrical energy, the transformation of the voltage value and high voltage insulation are realized by a medium frequency high voltage transformer; by using a high voltage sampling signal as an inverse feedback signal to control the duty cycle of the high frequency pulse width modulation output wave, the automatic stable regulation of the output high voltage is realized. Therefore, the device is characterized by little harmonic interference in the power network, quick system regulation, small output high voltage ripple, simple manufacturing and higher efficiency.

An apparatus (10) for detecting the occurrence of partial discharge in electrical equipment, such as high voltage transformers. The apparatus comprises a detecting means including an ultrasonic transducer (11) mounted at one end of an electrically insulating elongate rod (13). The ultrasonic transducer (11) is adapted to detect ultrasonic pulses or waves generated by the occurrence of a partial discharge in the electrical equipment. A radio frequency (RF) transducer (17) is also utilized to detect radio frequency (RF) pulses or waves also generated by the partial discharge. The rod (13) can be mounted in the wall of the electrical equipment and so provide a mechanism for adjusting the position of the detecting means within the electrical equipment. The apparatus is also removable from the electrical equipment and re-locatable to other equipment.

The invention discloses a high-frequency high-voltage transformer design optimization method based on a genetic algorithm. On the basis of a minimum loss formula of a transformer and the insulation dimension and the iron core shape of the transformer, a mathematical model is established, a genetic algorithm is adopted for optimizing the transformer by taking the number of turns of primary sides and the layer number of secondary sides as optimization variables and taking efficiency as an optimization target, so that the efficiency of the transformer is maximized, the loss of the transformer is minimized, temperature rise is minimized under an equal condition, the leakage inductance and the distribution capacitance of the transformer are fully utilized to participate in the work of a power system to form an LCC (Life Cycle Costs) resonance circuit, and the loss of the transformer is reduced so as to lower the temperature rise. Compared with the prior art, the invention introduces the genetic algorithm, the genetic algorithm exhibits a problem non-relevant quick and random search capability, searches by starting from a group and has the characteristic of concurrency, and a plurality of individuals can be simultaneously compared to greatly quicken optimal solution search speed.

Three example inverter designs are described that can be tailored to drive from one to dozens of lamps of a backlight for a liquid crystal display. For each design the lamps are driven by a 40 kHz to 60 kHz sine wave. The lamp voltage is ˜1200V to “strike” the lamps and ˜600V to produce the optimal 5 mA in each lamp. The designs are: a Royer linear oscillator driven by a buck converter stage, a push-pull inverter that drives the high voltage transformer directly, and a class-D amplifier that produces the drive sine wave using a pulse width modulation technique.

The invention relates to the technical field of a long duration induced voltage withstand test device of ultrahigh-voltage and extraordinarily high-voltage transformer, in particular to a long duration induced voltage withstand test device of an ultrahigh-voltage transformer. The long duration induced voltage withstand test device of ultrahigh-voltage transformer is characterized in that the test device includes a test power supply module, a test transformer, a test compensation reactor and a voltage divider; the test compensation reactor and the voltage divider are arranged in parallel between the test transformer and a to-be-tested transformer; and the test power supply module is connected with the test transformer. During the testing, the test device can directly determine the parameters of the compensation reactor desired for the test according to the type of the transformer by configuring the parameters of each part, thereby obviating the process for determining the parameters of the compensation reactor through a plurality of trails in the prior art. By using the symmetrical voltage applying method, the design insulation level of a single test transformer and a single reactor can be reduced. Accordingly, the test device is convenient in manufacture and is easy to transport in comparison to the existing equipment, and is more applicable, scientific, reasonable and economic in comparison to the equipment with high rated voltage.

The invention relates to a method for testing a step voltage and a touch voltage of a grounding grid, and especially relates to a short current electrode method for testing a step voltage and a touch voltage of a grounding grid. The test cost can be significantly reduced and the test efficiency is improved by proper reduction of a lay out of route distance of the current electrode under the premise of assurance of the test accuracy. The method for testing the step voltage and the touch voltage of the grounding grid influences step voltage and touch voltage test errors, and provides a selection principle of the current electrode lay out of route distance in a large grounding grid test. The selection principle is verified in the test of a super high voltage transformer station grounding grid, and test results well verify the accuracy and high efficiency of the short current electrode testing method provided by the invention.