With the development of national economic construction, there is an increasing demand for mobile power sources (also called mobile power stations) with multiple power supplies. In mobile operations such as national defense, communications, metallurgy, exploration, film and television, and transportation facilities, mobile power stations are needed, especially military. Equipment such as field vehicles, missile vehicles, and armored vehicles require multiple power supplies. At present, mobile power plant systems are mostly implemented using a variety of generator sets, power distribution and control equipment. Because the conventional electric excitation generator is bulky, and the permanent magnet generator has the problem of voltage regulation, it can not meet the requirements of the relevant mobile equipment, and has the characteristics of multiple power output, high efficiency, high power density and compact structure. In order to solve this problem, we have studied a new type of synchronous generator and a dual-supply output composite excitation rare earth permanent magnet synchronous generator. It adopts a composite excitation structure combining rare earth permanent magnets and auxiliary electric excitation. The magnetic fields generated by the two excitation magnets are combined in parallel to form an internal magnetic field of the synchronous generator. The stator part adopts a double-winding structure, and outputs two voltage levels (dual power output) while adjusting the auxiliary electric excitation, so that the output voltage of each winding can be kept constant under no-load and load conditions. This new type of synchronous generator takes into account the advantages of permanent magnet synchronous generators and electrically excited synchronous generators. In this paper, the structural principle and electromagnetic calculation of this motor are analyzed in detail, and the mathematical model of electromagnetic calculation is derived, and the motor is designed according to this. The test results of the prototype are basically consistent with the design results, which proves the correctness of the derivation.
2Structural principle The basic structure of the dual-voltage output composite excitation rare earth permanent magnet synchronous generator is shown in the figure. Two sets of windings are embedded in the stator armature winding, that is, two voltages are output. The rotor structure of the permanent magnet part adopts a tangential groove wedge structure; the auxiliary electric excitation part adopts a claw pole type structure, which is composed of the front and rear claws having the same number of claws and half of the pole number, and the electric excitation coil sandwiched between the two claws composition. The auxiliary electric excitation coil is fixed to the end cover through the magnetic guiding bracket, and the two claws are connected by a non-magnetic material and fixed on the rotating shaft. When it rotates with the rotor, an alternating potential is induced in the stator armature winding, and thus the entire motor is brushless.
Basic structure diagram of composite excitation rare earth permanent magnet synchronous generator When the motor runs under symmetrical load, the three-phase currents on the two sets of armature windings respectively establish the fundamental wave armature magnetomotive force and the magnetic potential generated by the permanent magnet And the excitation magnetomotive force generated by the electric field winding interacts to form a composite magnetomotive force in the air gap at the time of load, and establishes an air gap magnetic field at the time of load. One set of windings (called an AC winding) outputs an AC voltage, and the other set of windings (called a rectifying winding) outputs an AC voltage that is DC-rectified to provide DC power. During operation, the output voltages of both sets of windings can be kept constant by adjusting the magnetic field of the auxiliary electric excitation portion.
3 Electromagnetic calculation The composite excitation rare earth permanent magnet synchronous generator generates magnetic potential by the permanent magnet and the auxiliary electric excitation winding, and the working magnetic flux provided by the two in parallel is synthesized in the air gap. Here, the armature magnetic field and the magnetic flux per pole will be different when the armature magnetomotive force of the synchronous motor with uneven air gap acts at different positions, and the double reaction theory proposed by Blondel is needed. When the armature magnetomotive force neither coincides with the straight axis nor the intersecting axis, it can be decomposed into a direct axis component and a cross axis component for analysis, and finally their effects are superimposed. It is also assumed that the phase voltage and phase current of the AC winding and the rectifying winding of the dual-voltage composite excitation rare earth permanent magnet synchronous generator are both sinusoidal, which is a schematic diagram of the axis of the dual-voltage composite excitation rare earth permanent magnet synchronous generator. 0.5 Re-adjust the permanent magnet size and Winding parameters.
4 calculation examples and. Table 1 Design value and measured value Test item - Output terminal Remarks Auxiliary electric excitation Excitation form No-load No-Electric excitation Adjustment rated load No electric excitation adjustment No-load demagnetization condition Rated load Magnetic excitation condition Excitation current / Design voltage / V Measured voltage / V design voltage / V measured voltage / test conditions: 1. The speed is rated speed 4800r / min2 The maximum excitation voltage is DC 28V As can be seen from Table 1, the theoretical calculation value and the actual test value are basically consistent, indicating that the electromagnetic calculation derived in this paper The model meets engineering design requirements. Although the generator has a low voltage at rated load and a high voltage at no load, the output voltage can be adjusted to maintain a constant current by adjusting the auxiliary electric excitation portion current (magnetic or demagnetization).
Balance Bike Mini,Mini Walking Bike,Mini Glider Balance Bike,Mini Micro Balance Bike
ANDER LEISURE PRODUCTS CO.,LTD , https://www.anderbike.com