WO2013139060A1 - Ac generator - Google Patents

Abstract

An AC generator, comprising an engine (1) serving as a power source, two multi-pole high-frequency generators (M1, M2) having different numbers of magnetic poles, a commutation conductive ring (5), a carbon brush (6) and a rectifier circuit; the rotors of the two multi-pole high-frequency generators (M1, M2) are installed on the same rotor shaft (2) driven by the engine (1); the rotor coils of the two multi-pole high-frequency generators (M1, M2) are connected in series and are then connected to the input terminal of the rectifier circuit; the output terminal of the rectifier circuit is connected to the commutation conducting ring (5) also installed on the rotor shaft (2); and the commutation conducting ring (5) is in contact with the carbon brush (6) and outputs the required sinusoidal wave alternating current. The AC generator has a simple structure and a convenient production process, saves a great amount of silicon steel material and copper material, thus reducing cost, having a high power generating efficiency, and generating the sinusoidal wave alternating current having little waveform distortion and strong anti-interference capability.

Description

Alternator

 Technical field

 The invention relates to an alternator.

 Background technique

Inverter generators have developed rapidly in the field of small engine generators in recent years due to their small size, light weight and good electrical performance. The working principle of the existing inverter generator is to use a high-frequency generator to send a higher-frequency equal-amplitude alternating current, and the alternating current is rectified into a constant direct current by a rectifying method, and then converted into a Required alternating current, commonly known as ADA mode. Since the existing ADA inverter circuit is passed through a bridge circuit, the IGBT power transistor is used to chop the DC current and then pass through the LC. The circuit shapes the waveform and restores it to an AC sine wave. Because the IGBT power transistor is used at the chopping frequency 20K Working in a state will result in large switching losses, resulting in heat loss and power loss of the transistor, reducing efficiency, and high-power inductors used to shape the post-chopper waveform will also generate a large amount of heat, resulting in a larger Loss. Simultaneously Multiple harmonics of the 20K chopping frequency produce high-frequency radio waves that can be emitted. If the generator power is to be made larger, the radio electromagnetic waves are also larger, which will not pass the existing European EMC certification requirements.

Of course, in the prior art, the alternating current of the sinusoidal waveform is obtained by rectifying the higher frequency equal amplitude alternating current directly by the controllable rectification method and controlling the conduction angle at different times, but the waveform distortion is large, and The distortion changes more under different loads, which cannot meet the requirements of many electrical appliances. From a cost perspective IGBT high-power transistors used in ADA inverter mode, large-capacity electrolytic capacitors, high-power inductors are expensive, and IGBT Transistor specifications increase exponentially with increasing current, so generators that produce more than 5 kW or more will cost more. Therefore, it is still difficult to replace traditional generators with inverter generators.

The combination of two high-frequency alternating currents to generate an alternating current with an envelope is a well-known principle method, which produces a sinusoidal alternating current with a small waveform distortion. However, the above principle method has not been utilized in the field of the alternator industry.

 Summary of the invention

The object of the present invention is to provide an alternator which is not only simple in structure, convenient in production process, saves raw materials, has low cost, and has small waveform distortion and strong anti-interference ability, compared with the existing generator involved in the background art. Power generation efficiency is high.

The technical solution of the present invention is: an alternator comprising an engine as a power source, characterized in that it further comprises two multi-pole high-frequency generators having different magnetic pole numbers, a commutating conductive ring, a carbon brush and a rectifying circuit; The rotors of the two multi-pole high-frequency generators are mounted on the same rotor shaft driven by the engine, and the rotor coils of the two multi-pole high-frequency generators are connected in series and connected to the input end of the rectifier circuit, the rectification The output of the circuit is then coupled to a commutating conductive ring that is also mounted on the rotor shaft, the commutating conductive ring being in contact with the carbon brush to output the desired sinusoidal alternating current.

Preferably, the two multi-pole high frequency generators of the present invention are both outer stator inner rotor structures, and their stators are fixed in the same stator sleeve.

 In the present invention, according to the rotor 3000 rpm, the output AC frequency is 50 Hz. The general requirement is that the difference in the number of cycles between one multi-pole high-frequency generator and another multi-pole high-frequency generator is preferably two weeks, that is, two amplitude-modulated amplitude-modulated waveforms are generated, and the two-period-variable amplitude-modulated superimposed waveforms are passed. After rectification, form a The 50Hz AC is rectified forward DC ripple voltage waveform, and then the DC ripple voltage is commutated to output a desired sine wave AC through the commutating conductive ring and the carbon brush in contact therewith.

Preferably, in the present invention, the zero-crossing point of the envelope waveform formed by the high-frequency alternating current series connection of the two different pole-number multi-pole high-frequency generators and the commutation of the commutating conductive ring with respect to the carbon brush Align to the point angle.

Further, the present invention further includes a voltage controller, the output end of the rectifier circuit is first connected to the voltage controller and then connected to the commutating conductive ring; the voltage controller is configured to perform the rectified DC ripple voltage Adjust to achieve the stability of the alternator output voltage.

Of course, further, the voltage controller of the present invention is preferably mounted on the rotor shaft and rotates synchronously with the rotors of the two multi-pole high frequency generators. In a specific implementation, the voltage controller housing can be fixed to the rotor of any multi-pole high frequency generator.

In addition to the above method for adjusting the magnitude of the rectified DC ripple voltage by the voltage controller, the present invention provides another voltage regulation means as follows:

The stator poles of the two multi-pole high-frequency generators are all combined with a permanent magnet pole and an electric field pole, and the electric field pole coils on the two stators are connected to a voltage controller, and the voltage controller includes an alternating current power generation a sampling circuit for sampling the output voltage of the machine and an electric excitation magnetic pole coil driving circuit, wherein the electric excitation magnetic pole coil driving circuit uses the output end of the alternator as a power supply end or adopts another power supply end (for example, a power supply of an independent dedicated power supply magnetic pole coil) The voltage controller controls the voltage on the two rotor coils by adjusting the magnitude of the current on the electric field pole coils of the two stators to achieve stable output voltage.

Of course, preferably, the sampling circuit of the voltage controller and the electric field pole coil driving circuit of the present invention are connected to the commutating conductive ring, and the sampling circuit samples the alternating current output of the commutating conductive ring, and simultaneously excites The pole coil is powered by the alternating current output from the commutating conductive ring.

In addition, the rectifier circuit of the present invention can also adopt a conventional controllable rectifier circuit, and the controllable rectifier circuit is used to control the stability of the output voltage of the alternator, which is also a voltage regulation means.

The working principle of the invention is as follows: after the output coils of two multi-pole high-frequency alternators emitting different amplitude equal-amplitude alternating currents are connected in series, the waveform superposition will produce an amplitude which varies with the voltage difference of two equal-amplitude alternating currents. An amplitude modulation alternating current having an envelope, and then rectifying the amplitude modulated alternating current through a rectifying circuit to form a DC ripple voltage waveform having a sine wave rectified, and then connecting the DC ripple voltage to the commutating conductive ring, and finally passing The carbon brush in contact with the commutating conductive ring rectifies the DC ripple voltage and diverts it to form a desired sinusoidal alternating current.

 The advantages of the invention are:

Compared with the prior art generator, the invention has the advantages of simple structure, convenient production process, large amount of silicon steel material and copper material, thereby reducing the cost, and the electrical performance can reach most of the indexes of the current inverter generator, which are higher than the existing ones. The general-purpose generator's index, power generation efficiency is greatly improved compared with general-purpose generators, especially small-sized general-purpose generators. This saves on the cost of use and also reduces environmental pollution.

The invention can generate sinusoidal alternating current with small waveform distortion and no high-frequency radio electromagnetic wave interference, which not only has all the advantages of the existing inverter generator, but also has lower manufacturing cost than the existing inverter generator, and even Lower than the current general-purpose generator manufacturing cost, and there is no high-frequency radio electromagnetic wave, able to pass existing Europe EMC certification requirements.

 DRAWINGS

 The present invention is further described below in conjunction with the accompanying drawings and embodiments:

 1 is a schematic structural view of a specific embodiment of the present invention (the output voltage is stabilized by controlling a rectified DC ripple voltage);

 Figure 2 is a cross-sectional view taken along line A - A of Figure 1;

 Figure 3 is a B - B sectional view of Figure 1;

 Figure 4 is a schematic diagram of the electrical principle of the embodiment of Figure 1;

 Figure 5 A schematic structural view of another embodiment of the present invention (by controlling a portion of the electric field pole current to stabilize the output voltage);

 Figure 6 is a cross-sectional view taken along line C - C of Figure 5;

 Figure 7 is a cross-sectional view taken along line D - D of Figure 5;

 Figure 8 is a schematic diagram of the electrical principle of the embodiment of Figure 5;

 Figure 9 is a waveform of a constant amplitude alternating current generated by a multi-pole high-frequency generator;

 Figure 10 shows the amplitude of the alternating current waveform from another multi-pole high-frequency generator;

 Figure 11 is an alternating current waveform with an envelope after two equal-amplitude alternating currents of different frequencies;

 Figure 12 is a waveform of a DC ripple voltage after rectification of an alternating current with an envelope;

 Figure 13 shows the sinusoidal AC waveform after the commutation of the DC ripple voltage through the commutating conductive ring.

 Where: M1 and M2 respectively represent two multi-pole high-frequency generators with different magnetic pole numbers; 1. Engine; 2; rotor shaft; , rotor support; 4, stator sleeve; 5, commutating conductive ring; 6, carbon brush; 7, carbon brush holder; 8, voltage controller; Q1, Q2 respectively represent the rotor pole of two multi-pole high-frequency generator; R1 and R2 respectively represent the stator magnets of two multi-pole high-frequency generators; L1 and L2 respectively represent the electric field poles of the stators of two multi-pole high-frequency generators.

 detailed description

 Embodiment 1 : As shown in FIG. 1 - 4, the alternator provided in this embodiment has an engine as a power source. The power generating device part is characterized in that two multi-pole high-frequency generators M1 and M2 having different magnetic pole numbers are formed into a single structure, that is, two of the multi-pole high-frequency generators M1 and M2 The rotor is fixed to the same rotor support 3, and the rotor support 3 is fixed to the rotor shaft 2, which is connected to the output shaft of the engine 1. And two multi-pole high-frequency generators M1, M2 The stators are fixed to the same stator sleeve 4. The two multi-pole high-frequency generators M1 and M2 are made in different numbers of poles because the two multi-pole high-frequency generators M1 and M2 The number of poles is different, so it is fixed on the same rotor shaft 2. When rotating, two multi-pole high-frequency generators can emit high-frequency equal-amplitude AC at different frequencies. The rotor shaft 2 in this embodiment is also equipped with a voltage controller 8 And the commutating conductive ring 5, the carbon brush holder 7 is fixed in the stator sleeve 4, and the carbon brush 6 is fixed on the carbon brush holder 7. Combined with Figure 4, the two multi-pole high frequency generators M1, M2 The rotor coils are connected in series and connected to the input end of the rectifier circuit, and the output end of the rectifier circuit is connected to the commutating conductive ring 5 via the voltage controller 8, and the commutating conductive ring 5 is connected with the carbon brush 6 The sinusoidal alternating current required to contact the output.

 Specifically, as shown in FIG. 2 - 3, in this embodiment, the number of rotor poles Q1 of one of the multi-pole high-frequency generators M1 is 30. Extremely, another multi-pole high-frequency generator M2 has a rotor pole Q2 of 24 poles; a 30-pole multipole high-frequency generator M1 corresponds to a stator magnet R1 of 10 pairs of SN poles, 24 The pole multipole high frequency generator M2 corresponds to the stator magnet R2 is 8 pairs of SN poles. At a speed of 3000 rpm, the 30-pole multi-pole high-frequency generator M1 outputs three-phase 500 Hz equal-amplitude high-frequency alternating current (as shown in Figure 9), 24-pole multi-pole high-frequency generator M2 outputs three-phase 400 Hz equal-amplitude high-frequency alternating current (as shown in Figure 10).

 As shown in Figure 11 - 13, when working in this embodiment, two multi-pole high-frequency generators M1, M2 After the rotor coils are connected in series, the output voltages are superimposed to produce an alternating current with an envelope waveform (shown in Figure 11), which is then rectified by a rectifier circuit to form a sinusoidal rectified DC ripple voltage (Figure 12). Shown), the voltage controller of the generator 8 Installed on the rotor, since the voltage regulation of the direct current is much more convenient than the voltage regulation of the alternating current, the present embodiment preferentially selects the voltage adjustment of the DC ripple voltage through the voltage controller 8 The adjusted DC voltage is applied to the commutating conductive ring 5, which is also mounted on the rotor shaft 2, and finally passes through the carbon brush 6 in contact with the commutating conductive ring 5 The DC ripple voltage is rectified and drawn to form a desired sinusoidal alternating current (shown in Figure 13).

 Embodiment 2: As shown in FIG. 5 to FIG. 8, the alternator provided in this embodiment is the same as the first embodiment. In part, the engine 1 is provided as a power source, and the power generating device portion is characterized in that two multi-pole high-frequency generators M1 and M2 having different magnetic pole numbers are formed into a unitary structure, that is, two of the multi-pole high-frequency power generation machine The rotors of M1 and M2 are fixed to the same rotor support 3, and the rotor support 3 is fixed to the rotor shaft 2, which is connected to the output shaft of the engine 1. And two multipole high frequency generators The stators of M1 and M2 are fixed on the same stator sleeve 4. The two multi-pole high-frequency generators M1 and M2 are made in different numbers of poles because the two multi-pole high-frequency generators M1 and M2 The number of poles is different, so it is fixed on the same rotor shaft 2. When rotating, the two multi-pole high-frequency generators M1 and M2 can emit high-frequency equal-amplitude AC at different frequencies. Rotor shaft 2 in this embodiment A commutating conductive ring 5 is also mounted thereon, and a carbon brush holder 7 is fixed in the stator sleeve 4, and the carbon brush holder 6 is fixed on the carbon brush holder 7. Referring to FIG. 6 to FIG. 8, this embodiment 2 and embodiment 1 The difference is that the stator poles of the two multi-pole high-frequency generators M1 and M2 are combined with a permanent magnet pole and an electric field pole (ie, in the stator sleeve 4). The magnetic steel and the electric field poles are mounted on the two sides, and the electric excitation poles L1 and L2 on the two stators are connected to the commutating conductive ring 5 via a voltage controller 8. The two multi-pole high frequency generators M1 The rotor coil of M2 is connected in series and connected to the input end of the rectifier circuit, and the output end of the rectifier circuit is connected to the commutating conductive ring 5, and the commutating conductive ring 5 is connected with the carbon brush 6 The sinusoidal alternating current required to contact the output. The voltage controller 8 includes a sampling circuit for sampling the voltage of the output end of the alternator and an electric field pole coil driving circuit. In this embodiment, the voltage controller 8 The sampling circuit and the electric field pole coil driving circuit are both connected to the commutating conductive ring 5, the sampling circuit samples the alternating current outputted by the commutating conductive ring 5, and the electric exciting magnetic pole coil adopts the commutating conductive ring 5 The output AC power is supplied. The voltage controller 8 controls the magnitude of the voltage on the two rotor coils by adjusting the magnitude of the current on the coils of the electric field poles of the two stators, thereby achieving stabilization of the output voltage.

 Specifically, as shown in FIG. 6 and FIG. 7, in this embodiment, the number of rotor poles Q1 of one multi-pole high-frequency generator M1 is 30. In the pole, another multi-pole high-frequency generator M2 has a rotor pole Q2 of 24 poles. The 30-pole multi-pole high-frequency generator M1 corresponds to 8 pairs of SN pole permanent magnet stator magnets R1 and 2 pairs of SN The pole-excited magnetic pole L1, the 24-pole multi-pole high-frequency generator M2 corresponds to 6 pairs of SN pole permanent magnet stator magnets R2 and 2 pairs of SN pole electric poles L2. At a speed of 3000 In the case of rpm, the 30-pole multi-pole high-frequency generator M1 outputs three-phase 500 Hz equal-amplitude high-frequency alternating current (as shown in Figure 9), and the 24-pole multi-pole high-frequency generator M2 outputs three-phase. 400 Hz equal amplitude high frequency AC (as shown in Figure 10).

 As shown in FIG. 11 to FIG. 13, when the embodiment is specifically operated, the two multi-pole high-frequency generators M1 and M2 are The stators are respectively equipped with partial electric magnetic poles L1 and L2, and the electric field poles L1 and L2 are changed by the voltage controller 8. The magnitude of the current on the coil controls the magnitude of the voltage on the rotor coil to achieve a stable output voltage. By the two multi-pole high frequency generators M1, M2 The regulated equal-amplitude high-frequency alternating current is superimposed in series to produce an alternating current with an envelope waveform (shown in Figure 11), which is then rectified by a rectifier circuit to form a sinusoidal rectified pulsating DC voltage (Figure 12). The pulsating DC voltage is connected to the commutating conductive ring 5, and finally the DC ripple voltage is rectified and led out by a carbon brush 6 in contact with the commutating conductive ring 5 to form a desired sinusoidal alternating current (Fig. 13 Shown).

The embodiments described above are only intended to illustrate the technical concept and the features of the present invention, and the purpose of the present invention is to enable those skilled in the art to understand the present invention and to implement the present invention. Modifications made in accordance with the spirit of the main technical solutions of the present invention are intended to be included within the scope of the present invention.

Claims (9)

1. An alternator comprising an engine as a power source, further comprising: a multi-pole high frequency generator having different pole numbers, a commutating conductive ring, a carbon brush and a rectifying circuit; the two multipoles The rotor of the high-frequency generator is mounted on the same rotor shaft driven by the engine, and the rotor coils of the two multi-pole high-frequency generators are connected in series and connected to the input end of the rectifier circuit, and the output end of the rectifier circuit is connected A commutating conductive ring also mounted on the rotor shaft, the commutating conductive ring is in contact with the carbon brush to output a desired sinusoidal alternating current.
2.  2 . According to claim 1 The above described alternator is characterized in that the two multi-pole high-frequency generators are all outer stator inner rotor structures, and their stators are fixed in the same stator sleeve.
3. 3. According to claim 1 An alternator according to the invention; characterized in that the difference in the number of cycles of the two multi-pole high-frequency generators with different magnetic pole numbers at the same rotational speed is two weeks.
4.  4. According to claim 1 or 3 The above-mentioned alternator is characterized in that the zero-crossing point of the envelope waveform formed by the series connection of the high-frequency alternating currents of the two different pole-number multi-pole high-frequency generators and the commutating conductive ring The angle of the commutation point of the carbon brush is aligned.
5.  5. According to claim 1 The above-mentioned alternator is characterized in that it further comprises a voltage controller, the output end of the rectifier circuit is first connected to the voltage controller and then connected to the commutating conductive ring; the voltage controller is used for rectifying The magnitude of the subsequent DC ripple voltage is adjusted to achieve stability of the alternator output voltage.
6.  6 . According to claim 5 An alternator according to the invention is characterized in that the voltage controller is mounted on a rotor shaft and rotates synchronously with the rotors of two multi-pole high-frequency generators.
7.  7 . According to claim 1 or 2 An alternator is characterized in that: the stator poles of the two multi-pole high-frequency generators are combined with a permanent magnet pole and an electric field pole, and the electric field pole coils on the two stators are connected a voltage controller, the voltage controller includes a sampling circuit for sampling an output voltage of the alternator and an electric field pole coil driving circuit, wherein the electric field pole coil driving circuit uses the output end of the alternator as a power supply terminal or adopts other The power supply terminal controls the voltage on the two rotor coils by adjusting the magnitude of the current on the electric field pole coils of the two stators to achieve stable output voltage.
8.  8 . According to claim 7 The alternator is characterized in that: the sampling circuit of the voltage controller and the electric field pole coil driving circuit are both connected to the commutating conductive ring, and the sampling circuit outputs alternating current to the commutating conductive ring. Sampling, while the electric field pole coil is powered by the alternating current output from the commutating conductive ring.
9. 9. An alternator according to claim 1, wherein said rectifier circuit is a controllable rectifier circuit, and said controllable rectifier circuit controls the stability of the output voltage of the alternator.

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