40results about How to "Increase the excitation current" patented technology

In a hybrid car, or an electric motor-driven four-wheel-drive vehicle, in which an electric motor is driven directly by an output from a generator, vehicle running performance is enhanced. The output from the generator is controlled so as to maintain a generator torque in a range, in which the vehicle does not stall. Specifically, a driving apparatus for the hybrid car includes a second generator 2 driven by an engine 1 for driving one pair of either front or rear wheels 14, 15 , an electric motor 5 driven through directly receiving the output from the second generator 2 and driving the other pair of either the front or rear wheels 14, 15 , and a four-wheel-drive control unit 6 controlling driving of the second generator 2 and the electric motor 5 . When the engine 1 is in an overloaded condition, the four-wheel-drive control unit 6 limits the output of the second generator 2.

The invention relates to a method for controlling an alternator or alternator-starter of a motor vehicle, the electric machine being capable of providing an electric current, the strength of which varies on the basis of the excitation signal (EXC), a duty cycle being associated with each excitation signal, the method comprising the following steps: comparing the difference between the duty cycle values of two consecutive excitation signals at a predetermined threshold; if said difference is greater than the predetermined threshold, releasing a gradual response phase, during which the duty cycle of the excitation signals is gradually increased, particularly in a substantially linear manner; at the start of said gradual response phase, increasing the duty cycle of the consecutive excitation signals by a predetermined jump (D_B), then gradually increasing the duty cycle, the duty cycle jump at the start of the gradual response phase being less than or equal to the release threshold of the gradual response phase.

The invention discloses a gird-connected wind power generation system with self-adaptive speed regulation composite transmission based on a differential mechanism, belonging to the field of wind power development devices of regenerated clean energy. The wind power generation system comprises a wind wheel, a fixed speed ratio gearbox, a parallel shaft gear shunt transmission box, a differential gearbox, a low-power constant rotating speed drive device and a synchronous generator. According to the invention, the time varying rotating speed of the wind wheel and the constant rotating speed provided by the low-power constant rotating speed device are coupled to form a rotating speed adjusting system by utilizing the differential, so that the output rotating speed is constant; a speed change drive device and a real-time control speed regulation strategy are unnecessary for the system, so that the time varying rotating speed of the wind wheel can be automatically adapted, the time varying rotating speed of the wind wheel is converted to the constant rotating speed and is input into the synchronous generator, so that the synchronous generator is operated at the rated rotating speed. The control difficulty and the control cost are greatly reduced, the system structure and the control strategy are simplified, and the efficiency and the operation reliability of the speed regulation transmission system are improved.

The embodiment of the present invention discloses a novel zero-voltage switching full-bridge direct current converter, and its specific composition includes first to fourth switch tubes, first and second capacitors, first to sixth rectifier diodes, first and second 2. Isolation transformer, which also includes DC power supply, filter inductor and load resistance. This DC converter effectively solves the problems of narrow zero-voltage switching range of switching tube, primary side circulation loss, and rectified voltage oscillation, which are common in existing full-bridge converters. . The invention has the advantages of simple circuit structure, wide soft switching range, low output current ripple, high conversion efficiency and the like.

The invention discloses an energy conversion device with a low-temperature coil, and relates to the technical field of electromagnet excitation. The energy conversion device comprises a cold source module, a vacuum module, an external energy module, an internal energy module and a connecting module, wherein the cold source module is configured to provide a cold source for the vacuum module, the external energy module is configured to be located outside the vacuum module, the internal energy module is configured to be located inside the vacuum module, and the internal energy module and the external energy module are configured to be connected through the connecting module. The energy conversion device with the low-temperature coil further comprises a refrigerant module, the refrigerant module is configured to be located in the vacuum module, and the internal energy module is configured to be located in the refrigerant module. The connection module comprises a power electronic converter,the power electronic converter comprises a large current unit and a small current unit, the small current unit is configured to be located outside the vacuum module, and the large current unit is connected with the internal energy module through a large current lead.

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.

An electromagnetic speed regulator comprises an electromagnetic speed regulator body and a direct current excitation circuit. The electromagnetic speed regulator body is composed of an inner rotor, an outer rotor, an inner rotor shaft, an outer rotor shaft, a bearing, a combined bearing, conductive sliding rings, electric brushes, a conductive wire, a rotating speed sensor, a machine shell and a machine base; the direct current excitation circuit is composed of a controllable rectification circuit, a current sensor, an electric reactor, a control circuit and a connection conductive wire. A fixed air gap is formed between the inner rotor and an iron core magnetic pole of the outer rotor. The two conductive sliding rings are arranged on an outer rotor supporting plate, and the two electric brushes make sliding contact with the surfaces of the two conductive sliding rings; the conductive sliding rings are connected with a concentrated winding of the outer rotor, and the positive output end and the negative output end of the direct excitation circuit are connected with the two electric brushes. The inner rotor shaft and the outer rotor shaft are connected through the combined bearing. The electromagnetic speed regulator has the advantages of replacing a frequency converter, and providing a motor speed regulation method achieving high efficiency, energy conservation, firmness, reliability, low cost, no-load starting and no electromagnetic interference.