268 results about "Saturable reactor" patented technology

A power supply for a capacitive-resistive load includes plural paralleled phase correcting modules together with current sharing controllers for tending to equalize their currents. Each module is provided with a diode, poled to prevent forward current from flowing in the return current path, for aiding in equalizing module currents. Surge currents are reduced by a single saturable reactor coupled to the combined outputs of current sharing controllers, thereby avoiding the need for soft-start in each controller. A precharging path extends from a source of pulsating direct voltage to the load, for precharging the load capacitance at turn-on.

A new type of the passive non-dissipative snubber with a single saturable reactor improves the performance of the boost converter used as a front-end active Power Factor Correction (PFC) in two critical areas: excess voltage stresses caused by high voltage spikes on input high voltage switching transistor of the boost converter is eliminated and EMI noise is much reduced. The high voltage spike energy instead of being dissipated as in a dissipative snubber circuits is recovered resulting in increased conversion efficiency. High voltage spike elimination also allows use of lower voltage rated devices with lower ON resistance, hence further increasing the efficiency of the PFC boost converter.

A magnetic amplifier includes a saturable core having a plurality of legs. Control windings wound around separate legs are spaced apart from each other and connected in series in an anti-symmetric relation. The control windings are configured in such a way that a biasing magnetic flux arising from a control current flowing through one of the plurality of control windings is substantially equal to the biasing magnetic flux flowing into a second of the plurality of control windings. The flow of the control current through each of the plurality of control windings changes the reactance of the saturable core reactor by driving those portions of the saturable core that convey the biasing magnetic flux in the saturable core into saturation. The phasing of the control winding limits a voltage induced in the plurality of control windings caused by a magnetic flux passing around a portion of the saturable core.

The invention relates to a device for improving performance of a direct-current saturable reactor and a method of the device. Controllable resistors are used for enabling the adjustment response speed of the direct-current saturable reactor to be increased. The device comprises the direct-current saturable reactor, controllable resistors M1 and M2 and a control circuit, wherein the dotted terminal of a coil L5 and the dotted terminal of a coil L8 are connected with a terminal I; the different-polarity terminal of a coil L7 and the different-polarity terminal of a coil L6 are connected with a terminal II; the different-polarity terminal of the coil L5 is sequentially connected in series with the controllable resistors M1 and M2 and then is connected with the dotted terminal of the coil L7; a node between the controllable resistors M1 and M2 is connected with the dotted terminal of the coil L6 through a positive thyristor D3, and is further connected with the different-polarity terminal of the coil L8 through a positive thyristor D4; the triggering terminals of the thyristor D3 and the thyristor D4 are connected with the control circuit; the control circuit controls the trigger angles of the thyristors, so as to continuously adjust the reactance value of the direct-current saturable reactor; the control terminals of the controllable resistors M1 and M2 are connected with the control circuit.

A magnetic core for use in a saturable reactor made of an Fe-based soft-magnetic alloy comprising as essential alloying elements Fe, Cu and M, wherein M is at least one element selected from the group consisting of Nb, W, Ta, Zr, Hf, Ti and Mo, and having an alloy structure at least 50% in area ratio of which being fine crystalline particles having an average particle size of 100 nm or less. The magnetic core has control magnetizing properties of a residual operating magnetic flux density DELTABb of 0.12 T or less, a total control operating magnetic flux density DELTABr of 2.0 T or more, and a total control gain Gr of 0.10-0.20 T/(A/m) calculated by the equation: Gr=0.8x(DELTABr-DELTABb)/Hr, wherein Hr is a total control magnetizing force defined as a control magnetizing force corresponding to 0.8x(DELTABr-DELTABb)+DELTABb.

The invention relates to a magnetic control shunt reactor digital simulation modeling method, which is characterized in that the method comprises a decomposition method of an equivalent magnetic circuit, and according to magnetic circuit laws and circuits laws, the magnetic control shunt reactor module can be equivalent to a plurality of saturated transformers and reactor modules; the invention uses saturated transformers and saturated reactors in prior simulation software and forms a magnetic control shunt reactor simulation module, which has clear principles, easy process and realization, has reliable and accurate module, and can be integrated in to prior simulation software to expand prior simulation functions; the digital simulation modeling method of the invention provides effective means for a steady control method and a transient control method of an inspection system.

A power supply for a capacitive-resistive load includes plural paralleled phase correcting modules together with current sharing controllers for tending to equalize their currents. Each module is provided with a diode, poled to prevent forward current from flowing in the return current path, for aiding in equalizing module currents. Surge currents are reduced by a single saturable reactor coupled to the combined outputs of current sharing controllers, thereby avoiding the need for soft-start in each controller. A precharging path extends from a source of pulsating direct voltage to the load, for precharging the load capacitance at turn-on.

The invention discloses a method for analyzing the performance of a saturation reactor for a converter valve under the condition of switching on a thyristor. Based on the current enduring capability of the thyristor under the condition of switching on the thyristor, the effects of different combinations of parameters of the saturation reactor on an applied electric power stress under the condition of switching on the thyristor are analyzed. The current enduring capability serving as a threshold value of the thyristor in each time segment in a switch-on period is analyzed emphatically to obtain an equivalent model of the saturation reactor and the thyristor in different time segments, and a current component of the thyristor is analyzed in different time segments to obtain the parameters of the saturation reactor required by protecting normal switch-on under the condition of switching on the thyristor. The analysis method lays theoretical and simulation foundations for the determination of the design optimization of the electric performance and electric parameter of the saturation reactor.

The invention relates to an alternating-current saturation reactor. According to the alternating-current saturation reactor, direct current is not needed, the size is small, and the cost is low. The alternating-current saturation reactor comprises a terminal I, a terminal II, a terminal III, a closed loop iron core alternating-current coil L1 and an alternating-current saturation reactor regulator, wherein the closed loop iron core alternating-current coil L1 is connected between the terminal I and the terminal II, the alternating-current saturation reactor regulator is connected between the terminal II and the terminal III, and the alternating-current saturation reactor regulator is a voltage distribution and regulation device; when an alternating-current saturation reactor regulator control circuit does not work, the nominal voltage of the alternating-current saturation reactor regulator is obtained; when the alternating-current saturation reactor regulator control circuit works, the control circuit regulates and controls the voltages across the two ends of the alternating-current saturation reactor regulator to be lower than the nominal voltage; regulation of the reactance of the alternating-current saturation reactor regulator is achieved by regulating the alternating voltages across the two ends of the alternating-current saturation reactor regulator.

The invention relates to a magnetic saturation reactor, which can reduce the volume and the weight of the magnetic saturation reactor under the condition of meeting performance requirements and can reduce the reactance of the magnetic saturation reactor in a magnetic saturation state. The magnetic saturation reactor comprise a theta-shaped structural magnetic saturation reactor core, wherein a reactive coil L1 and a direct current coil L2 are respectively arranged on one side of the magnetic saturation reactor; a reactive coil L3 and a direct current coil L4 are respectively arranged on the other side of the magnetic saturation reactor; the corresponding end of the reactive coil L1 is one alternating current terminal I of an alternating current loop of the magnetic saturation reactor; the unlike end of the reactive coil L1 is connected with the corresponding end of the reactive coil L3; the unlike end of the reactive coil L3 is the other alternating current terminal II of the alternating current loop of the magnetic saturation reactor; the corresponding end of the direct current coil L2 is connected with the corresponding end of the direct current coil L4; the unlike end of the direct current coil L2 is one direct current terminal I of the alternating current loop of the magnetic saturation reactor; and the unlike end of the direct current coil L4 is the other direct current terminal II of the alternating current loop of the magnetic saturation reactor.

The invention relates to a soft starter of low-voltage motor and high-voltage motor consisting of a three-phase rectifying bridge and relating to the non-impact current starting and speed control of an AC motor, wherein a motor stator three-phase winding is connected with the AC side of a three-phase fully-controlled rectifying bridge, while the DC side of the rectifying bridge is communicated by a conducting wire, thereby forming a low-voltage soft starter; the low-voltage AC exciting coil of a three-phase saturable reactor is connected with the AC side of the three-phase fully-controlled rectifying bridge, while the DC side of the rectifying bridge is communicated by a conducting wire and a high-voltage motor stator three-phase winding is connected in series with the high-voltage coil of the saturable reactor, thereby forming a high-voltage motor soft starter. The high voltage/low voltage soft starter has a full-voltage electromagnetic switch capable of charged attracting when a motor starts; when starting is finished, the electromagnetic switch is capable of powerdown release to ensure full-voltage operation of the motor; moreover, when adopting the 'one-drive-N' proposal, the soft starter needs to be equipped with N motor circuit breakers but omits N+1 electromagnetic switches as compared with the prior soft starter.

The invention belongs to the technical field of thermally conductive and insulating materials, and particularly relates to an epoxy resin thermally conductive insulating material and a preparation method thereof. The material includes an epoxy resin basic material, inorganic filler and a curing agent, wherein the inorganic filler is composed of fillers of three different particle sizes. The epoxyresin thermally conductive insulating material has excellent thermal conductivity and insulation performance only through selection of the ratio of three different particle size grading of the inorganic filler, the ratio of the use amount of the filler of different particle sizes and the particle sizes, and no surface-modified inorganic filler is needed, so that the material cost is reduced, and the preparation method of the material is simpler. The thermal conductivity of the material can reach 1.25 W.m<-1>.K<-1> at 30 DEG C, the highest thermal conductivity can reach 1.62 W.m<-1>.K<-1>, theresistivity of the material is 2.9x10<16> omega.cm or above below 30 DEG C, and application requirements of power electronic transformers, saturation resistors and other high insulation scenes can bemet fully.

The invention relates to a testing method for dynamic inductance, and in particular relates to the testing method for the dynamic inductance of a saturable reactor of a direct-current converter valve. The testing method comprises the following steps of: A. setting up a testing circuit of the saturable reactor; B. testing the voltage of a dynamic inductance end of an iron core of the saturable reactor; C. applying low frequency sinusoidal steady state excitation to the saturable reactor; D. testing the electric current of a dynamic inductance branch of the iron core; E. determining the electromagnetic parameter of the dynamic inductance of the iron core; and F. determining the dynamic inductance of the iron core. According to the testing method, the circuit characteristic measurement for determining the dynamic inductance of the iron core is converted into a electromagnetic field parameter through strict test and calculation on the basis of the dynamic inductance definition, thereby reducing the computational complexity and numerical errors; the physical property of the dynamic inductance is expressed by adopting the parameter of the port of the saturable reactor through a reasonable physical hypothesis, thereby avoiding the direct measurement on the parameters of the two ends of the dynamic inductance and greatly reducing the test complexity; and equipment needed for tests is simple and frequently-used; and the test process is easy to operate.

The present invention is directed to a transient suppressor, a method of suppressing a peak voltage associated with a rectifier, and a power converter employing the same. In one embodiment, the transient suppressor includes a saturable reactor circuit interposed between a rectifier and a transformer winding. The transient suppressor also includes a RC circuit, coupled between the rectifier and the saturable reactor circuit and across the transformer winding, configured to cooperate with the saturable reactor circuit to suppress a peak voltage associated with the rectifier.

The invention relates to a direct-current saturable reactor rapid in reaction. The reaction speed of the direct-current saturable reactor is increased through series resistors. The direct-current saturable reactor rapid in reaction comprises a direct-current saturable reactor closed-loop iron core, the closed-loop iron core is provided with at least two iron core columns with the same cross section, the two iron core columns are each provided with an alternating current coil and a direct current coil, the dotted terminals of all the alternating current coils and the direct current coils are connected with a terminal I, remaining terminals of all the alternating current coils are connected with one resistor in series and then connected with a terminal II, the remaining terminal of one direct current coil is connected with a positive thyristor and one resistor in series and then connected with the terminal II, the remaining terminal of another direct current coil is connected with a negative thyristor and one resistor in series and then connected with the terminal II, the control terminals of the thyristors are connected with a control circuit, and the control circuit controls the fire angles of the thyristors so as to continuously adjust the reactance value of the direct-current saturable reactor.

The invention discloses a current limiting device with flexible switch characteristic and a current limiting method. The current limiting device can decrease and nearly turn off the normal load current and the short-circuit current when control equipment gives a disconnection command and can connect the normal load when the control equipment gives a connection command so that the user can use electricity normally and the performance-price ratio is relatively high. The current limiting device comprises magnetic saturable reactor iron cores I and II, a magnetic saturable reactor coil L1 and a direct-current coil L2 which are arranged on the magnetic saturable reactor iron core I, a magnetic saturable reactor coil L3 and a direct-current coil L4 which are arranged on the magnetic saturable reactor iron core II, a full bridge rectification circuit composed of diodes D1, D2, D3 and D4, two diodes D5 and D7, a thyrister D6, a control circuit, a capacitor C, and two resistors R1 and R2.

A power supply system for an arc furnace includes a three phase transformer assembly, back to back SCRs coupled between a power source and the three phase transformer assembly primary windings, and three saturable-reactors, coupled between the three phase transformer assembly secondary windings and a load. A controlled DC current source is coupled between a system controller and each of said three saturable-reactors. The system controller is configured for monitoring the power source and an output current at the load, and for controlling the back-to-back SCRs and the current source.