39results about How to "Increase the excitation current" patented technology

The invention discloses an auto-excitation type retarder with a water-cooling system, which comprises a vortex induction cylindrical stator, a rotor, an iron core and a transmission axle, wherein the transmission axle is connected with the rotor, the stator is positioned on the outer layer of the rotor, the iron core and an exciting coil thereof are arranged outside the rotor, the permanent magnetic pole of an electric generator is arranged at the inner side of the rotor, and an armature and a coil thereof of a generating set are connected to a stator fixing frame; a cooling water channel is arranged inside the stator, a water channel outlet and a water channel inlet are arranged on the surface of the stator, and the cooling water channel is communicated with the outside via the water channel outlet and the water channel inlet. When a vehicle brakes at moderate speed, the load of the engine is reduced, the requirement for the heat dispersion is also lowered, therefore, the cooling fluid in the cooling water channel can be directly adopted for cooling for the retarder. The invention has the advantages of simple structure, saved energy resources, enhanced generating capacity of the generating set for the retarder, increased exciting current of the retarder and increased braking torque and retarded braking effect of the retarder.

The invention relates to an intelligent control module for opening-closing electromagnets of a circuit breaker. The intelligent control module comprises an input power supply, a rectifier and filter circuit and a power electronic switch, wherein the units are connected successively. The output terminal of the power electronic switch is connected with input terminals of a closing coil and an opening coil; output terminals of the closing coil and the opening coil are connected with a normally-open contact and a normally-closed contact of a single-pole double-throw relay. A fixed end of the single-pole double-throw relay is connected with an input terminal of a hall current sensor; an output terminal of the hall current sensor is connected with a controller connected an input terminal of an isolated drive circuit; and an output terminal of the isolated drive circuit is connected with the power electronic switch to complete closed-ring control of a coil current. According to the invention, closed-loop chopper control on coil currents of the opening-closing electromagnets is realized, so that the excitation way of the opening-closing electromagnets is changed fundamentally.

The invention provides a processing method for unstable signals of an electromagnetic flowmeter under conditions of high frequency excitation, which comprises the following steps: an input signal is directly inputted to an analog-to-digital conversion circuit for signal preprocessing; an interference model is constructed, and the characteristic quantity of the dynamic variation of differential interference signals after signal preprocessing is extracted according to the interference model; the differential interference signal is obtained according to the characteristic quantity, and the process of removing the differential interference signal is carried out, and then an output signal of the conducting fluid flow is obtained. The processing method for the unstable signals of the electromagnetic flowmeter under conditions of high frequency excitation has the advantages that the steady speed of currents can be increased and the time for magnetic field excitation can be shortened, therebyreducing current consumption of the device; the using time of battery-powered products can be effectively prolonged; the excitation current in the time for effective signal acquisition can be enhanced, and the signal to noise ratio can be enhanced, thereby solving the problem of the instability of the zero point caused by the introduced interference under conditions of high frequency excitation above 100 Hz.

The invention discloses a superconducting electric electromagnetic hybrid maglev train, which comprises L-shaped suspension frames and an I-shaped ground rail, and is characterized in that the upper end of each suspension frame is connected with a train body through an air spring; the suspension frames are arranged on the two sides of the ground rail, and the suspension frames and the ground railare arranged at intervals. A plurality of superconducting magnets is arranged at the lower end of each suspension frame. An 8-shaped upper-layer suspension coil and an 8-shaped lower-layer suspensioncoil are arranged at the upper end and the lower end of the ground rail respectively, an upper-layer power generation coil and a lower-layer power generation coil are arranged at the lower end of thesuspension frame, and the upper-layer suspension coil is electrically connected with the lower-layer suspension coil; and a propelling coil is arranged above the upper-layer suspension coil. The invention has the advantages of large operation air gap, self-stabilization, good suspension guiding dynamic performance, better curve passing capacity, higher superconducting magnet magnetic field utilization rate and lower track construction cost.

The invention discloses a phase fracturing type two-phase exciter and a starting control method. The phase fracturing type two-phase exciter is a rotating armature type electro-magnetic synchronous motor and is of a non-salient pole structure. Two phases of symmetric windings are placed on a stator, and the phase difference of the axes of the two phases of symmetric windings in space is a 90-degree electrical angle. An AC capacitor is singly connected into one phase of winding in series, and is connected with two phase lines or a phase line and a neutral line of a three-phase AC starting powersource. Through the phase fracturing effect of the AC capacitor, the exciter generates an oval or even circular magnetic field under a single-phase AC excitation condition, the counter potential obtained by a three-phase armature winding of a rotor of the exciter is improved, the excitation efficiency is improved, and the excitation currents of a main motor during starting are increased. Comparedwith a traditional single-phase AC exercitation method, the problems that single-phase AC exercitation currents and power are insufficient in the whole starting process of a three-stage brushless synchronous motor are solved, particularly under a static and low-speed condition, the starting control method is simple and reliable, switching is easy, and the starting and power generating integratedfunction is achieved.

An embodiment of the invention discloses a transformer, comprising a primary coil and a secondary coil. The primary coil is electrically connected with a power supply, and the secondary coil is electrically connected with a load, wherein a hollow structure is provided between the primary coil and the secondary coil, the primary coil and the secondary coil are superconducting coils, a controllable capacitor is disposed between the primary coil and the power supply, and the controllable capacitor and the primary coil are connected in parallel. Compared with the prior art, the transformer provided by the embodiment of the invention has no core structure; on one hand, exciting current is greatly increased, and high sensitive reactive power compensation can be provided for a system as leakage reactance increases; the other hand, the saturation problem of a core is basically solved, transformer capacity is improved, and the setting of the superconducting coils reduces total loss of the transformer and improves transformer efficiency on the whole.

The invention relates to a wide-range current measurement method and device based on closed-loop feedback, and a current sensor. The current sensor comprises a magnetism gathering ring, a single-axis TMR chip and a current generation module. A wire to be measured penetrates through the magnetism gathering ring, the uniaxial TMR chip is arranged in an air gap of the magnetism gathering ring and used for outputting a voltage signal, the current generation module is used for outputting excitation current to an excitation coil of the magnetism gathering ring, and the direction of the magnetic field intensity generated by the excitation current in the air gap is opposite to the direction of the magnetic field intensity generated by the current of the wire to be measured in the air gap. The method comprises: acquiring a voltage signal; under the condition that the single-axis TMR chip works in a linear region, the current of the wire to be measured is obtained according to the voltage signal; and under the condition that the single-axis TMR chip works in the non-linear region, the exciting current is increased, so that the single-axis TMR chip works in the linear region, and the current of the wire to be measured is obtained according to the voltage signal and the exciting current. The current detection range is widened on the basis of high-precision current detection.

The invention belongs to the electric power measuring technology and particularly relates to an induction type electric energy meter of which a rated maximum current Imax is eight times as large as a basic current Ib. The induction type electric energy meter comprises driving elements and rotation elements, wherein the rotation elements comprise a rotation shaft, a rotation disc and a lower shaft tip, the rotation disc and the rotation shaft are in movable connection, a lower portion of the rotation disc is provided with an upper magnetic ring, the upper magnetic ring and the rotation shaft are in movable connection, a top portion of the lower shaft tip is provided with a lower magnetic ring, the lower magnetic ring and the lower shaft tip are in fixed connection, the driving elements comprise a voltage element, a current element and a magnetic shunt, and the magnetic shunt is arranged between the voltage element and the current element. Performance of an integral machine formed through the induction type electric energy meter satisfies single-phase and three-phase electric energy meter requirements in related long-life technology electric energy meter standards in domestic and industries, and a flat straight curve can be acquired within a 5%Ib-800%Ib broad loadscope.

The invention provides a DC velocity modulation device that is applicable to a large-power DC motor. The device consists of an excitation part, an armature-voltage part, a controlling part and an alarming part, wherein, the excitation part consists of a circuit module, an excitation winding and a mutual-inductor. The invention is characterized in that the mutual-inductor comprises a primary mutual-inductor Cu1 and a secondary mutual-inductor Cu; the circuit module comprises a half-controlled bridge rectification circuit that is composed of a controllable silicon and a diode. The invention adopts the secondary mutual inductance method to enlarge the excitation current of the DC velocity-modulation device according to the principle of the transformer, thereby having simple method and low cost.

The invention provides a distinguishing method and distinguishing device of a left-handed rotation light and a right-handed rotation light of a light source spectral line in a magnetic field, belonging to the technical field of spectrum measurement. The distinguishing device of the left-handed rotation light and the right-handed rotation light of the light source spectral line in the magnetic field specifically includes a light source, an electromagnet, a collecting lens, an interference filter, a 1/4 wave plate, a polarizer, an F-P etalon, a telescope, and a camera phone. The light source isplaced in the magnetic field generated by the electromagnet; and the collecting lens, the interference filter, the 1/4 wave plate, the polarizer, the F-P etalon, the telescope, and the camera phone are successively arranged parallel to the direction of the magnetic field in order from front to back and are coaxial with the light source. By means of the distinguishing method and distinguishing device of the left-handed rotation light and the right-handed rotation light of the light source spectral line in the magnetic field provided by the invention, not only the left-handed rotation light andthe right-handed rotation light can be distinguished, and reference can be provided for further analysis and research of the left-handed rotation light and the right-handed rotation light, but also the distinguishing device has a low cost, and the distinguishing method has simple process and easy operation.

The invention relates to an electromagnetic metering pump driving circuit and a control method. The method comprises the following steps: calculating operation parameters such as a starting pulse sequence number, an active demagnetization starting current, an active demagnetization starting time, a demagnetization process starting duty ratio and the like of each step in a stroke frequency period according to system setting and hardware parameters; the K1 is switched off, and the K2 and the K3 are directly switched on; k1 and K2 are driven by using complementary PWM (Pulse Width Modulation) waveforms inserted into a dead zone, and K3 is kept on; the K1 is kept in an off state, and the K2 and the K3 are kept in an on state; k1 is kept in a turn-off state, K2 is kept in a turn-on state, and K3 is driven in a PWM mode; in the liquid suction process, the structure is recovered, and stroke frequency parameters are detected; through the active demagnetization function of the driving control electromagnetic pump and the electromagnetic coil, the characteristic of short demagnetization time is achieved to meet high-speed driving, the driving control method meets the requirement for convenient configuration of driving parameters of the controller, the maximum stroke frequency and the maximum pumping pressure range are effectively expanded, and meanwhile the design requirement for a heat dissipation structure of a pump body is lowered.

The invention provides an electric locomotive motor system, which comprises a motor body, and is characterized in that the motor body is internally provided with an excitation device for providing a working magnetic field, and the excitation device is electrically connected to a power supply through a constant value resistor; a dynamic resistor is connected in parallel to the constant-value resistor; the dynamic resistor comprises a closed inner cavity; mercury is sealed in the inner cavity; conductive metal rods which are parallel to each other and extend along the longitudinal direction of the whole inner cavity are equidistantly distributed above the mercury liquid level at intervals of 1-2mm; and one of the two adjacent conductive metal rods is electrically connected to a first electrode of the dynamic resistor after being connected with a protective resistor in series, and the other conductive metal rod is electrically connected to a second electrode of the dynamic resistor afterbeing connected with the protective resistor in series. The motor system can automatically adjust the output power of a motor according to the real-time road surface condition of the electric locomotive, so that the electric locomotive obtains better road surface trafficability.