JP5300427B2 - Rectifier circuit for power generator for distributed power supply - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the following problem: a winding having a large number of turns must increase its dielectric voltage because of generation of high voltage in a permanent magnet generator of generating equipment for distributed power supply having a plurality of types of windings for obtaining maximum outputs from wind power or the like without a PWM converter. <P>SOLUTION: In the rectification circuit of the generating equipment for distributed power supply, a reactor is connected to an output terminal of each of a first and a second three-phase winding insulated of a permanent magnet generator and DC outputs obtained from each alternating current are connected with each other in parallel and are output to the outside. The first three-phase winding is connected with a full-wave rectification circuit through the reactors. The second three-phase winding is connected with a voltage doubler rectification circuit of each phase through the reactors on a phase-by-phase basis. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a rectifier circuit of a power generator for a distributed power source for extracting a maximum output obtained from wind or water from a permanent magnet generator driven by a wind turbine or a water turbine, regardless of wind speed or flow velocity, and in particular, PWM. The present invention relates to a rectifier circuit of a power generator for a distributed power source that performs constant voltage charging without using a converter.

  The present applicant has first wound the stator of the permanent magnet generator 3 driven by a wind turbine or a water turbine, and outputs it to the insulated output terminals of the first three-phase winding and the second three-phase winding, respectively. In a distributed power generator that connects reactors and outputs the DC output obtained from each AC in parallel and outputs to the outside, the first three-phase winding is connected to a three-phase full-wave rectifier circuit via a reactor, The second three-phase winding is connected to the single-phase full-wave rectifier circuit through the reactor, and two of the three phases are connected in parallel to the DC side of the single-phase full-wave rectifier circuit. A rectifier circuit of a power generator for a distributed power source, characterized by being connected to the midpoint of a two series capacitor, is proposed (see, for example, published patent document 1).

The prior application technique will be described in detail with reference to a main circuit connection diagram showing a power generator for a distributed power source connected to the wind turbine of FIG.
In FIG. 5, 1 is a windmill, 2 is a rectifier circuit of a distributed power generation device of the prior application, 3 is a permanent magnet generator, 4 is a first reactor, 5 is a second reactor, and 61 is a three-phase all Wave rectifier circuit, 62 is a single-phase full-wave rectifier circuit, 81 is a first three-phase winding output terminal, 85 is a second three-phase winding output terminal, 11 is a positive output terminal, and 12 is a negative output terminal , 13 is a battery, 14 is a first capacitor, 15 is a second capacitor, 16 is a series capacitor circuit, and 74 is a double booster circuit.

In FIG. 5, the first three-phase winding output terminal 81 connected to the first three-phase winding is connected to the first reactor 4 and further connected to the three-phase full-wave rectifier circuit 61.
The second winding output terminal 85 connected to the second three-phase winding is connected to the second reactor 5, and two of the three phases are connected to the single-phase full-wave rectifier circuit 62, The other phase is connected to the midpoint S of the series capacitor circuit 16 connected in parallel to the DC side of the single-phase full-wave rectifier circuit 62. The series capacitor circuit 16 includes a first capacitor 14 and a second capacitor 15 connected in series. The single-phase full-wave rectifier circuit 62 and the series capacitor circuit 16 constitute a double boost rectifier circuit 74.
The direct current sides of the three-phase full-wave rectifier 61 and the single-phase full-wave rectifier 62 are connected to the positive output terminal 11 and the negative output terminal 12, and the total output of each winding is charged in the battery 13.

A method for obtaining the maximum output of the wind turbine from the power generator 2 for distributed power supply configured as described above will be described below.
FIG. 4 is a diagram for explaining the outline of the wind turbine rotation speed versus the wind turbine output characteristic when the wind speed is used as a parameter.
In the windmill, when the shape of the windmill and the wind speed U are determined, the windmill output P with respect to the windmill rotational speed N is uniquely determined. For example, the windmill output P with respect to the wind speeds Ux and Uy is shown in FIG. And the peak of the windmill output P with respect to various wind speeds becomes like the maximum output curve Pt shown in FIG.
That is, when the wind speed is Ux in the wind turbine rotation speed vs. wind turbine output characteristics of FIG. 4, the wind turbine maximum output Px at the wind turbine rotation speed Nx as indicated by the intersection Sx of the wind turbine output curve of the wind speed Ux and the maximum output curve. It becomes.
When the wind speed is Uy, the windmill maximum output Py at the wind speed Uy is obtained at the windmill rotational speed Ny.

  That is, looking at the maximum output curve of FIG. 4 in a different way, in order to obtain the maximum output from the wind, when the wind turbine rotation speed N is determined, the output P of the permanent magnet generator 3 at that time is uniquely determined. This indicates that the value may be determined on the maximum output curve Pt.

  FIG. 3 is an explanatory diagram in the case where the DC output of the distributed power generator 2 targeted by the prior application technique is connected to a constant voltage source such as a battery. The outputs of the first and second three-phase windings wound in the same number of turns in the permanent magnet generator 3 of the power generator 2 for the distributed power source are the difference in the effective value of the induced voltage of each winding, the internal inductance of each winding, Due to the voltage drop due to the reactor connected to each output terminal and the presence or absence of the double booster circuit, P1 and P2 shown in the wind turbine rotation speed versus output characteristic of FIG. 3 are obtained.

That is, when the wind turbine rotational speed N is low, the voltage generated in the first and second three-phase windings in the permanent magnet generator 3 is lower than the battery voltage Vb, so the battery 13 is not charged.
The second three-phase winding is connected to the midpoint S of the single-phase full-wave rectifier circuit 62 and the series capacitor circuit 16 via the second three-phase winding output terminal 85 and the reactor 5, and the first capacitor The total voltage of 14 and the second capacitor 15 is output to the battery 13.

  Here, each DC voltage of the first capacitor 14 and the second capacitor 15 is charged to half of the voltage of the battery 13 if the capacitor capacity is the same. Accordingly, when the wind turbine rotation speed N increases and reaches N2, charging of the battery 13 is started from the second three-phase winding. For example, when the number of turns of the second three-phase winding is equal to the number of turns of the first three-phase winding, the windmill speed N2 in FIG. 3 becomes a voltage that can be charged at half the windmill speed N1, and the battery 13 Will start charging.

  When the wind turbine rotational speed N increases, the current of the second three-phase winding increases as the wind turbine rotational speed N increases, and the output by the second winding becomes P2. At this time, even if the wind turbine rotation speed N increases and the induced voltage increases, the battery voltage is substantially constant, but the inductance of the second winding and the impedance of the second reactor 5 are proportional to the frequency. At the same time, the output P2 only increases gradually.

The output of the first winding is output to the battery 13 via the first winding output terminal 9, the reactor 4, and the three-phase full-wave rectifying circuit 61 when the wind turbine rotational speed N increases to N1.
As for the first three-phase winding, an output can be obtained by further increasing the rotational speed N, but a large output can be obtained because the internal inductance of the first winding and the second reactor 4 are small.

The output to the constant voltage source such as the battery 13 of the distributed power generator 2 configured as described above is obtained by adding the outputs P1 and P2 of the first and second windings in the permanent magnet generator 3. It is almost the same as the maximum output curve Pt which is the total output obtained.
JP 2006-238539 A (FIG. 1)

  FIG. 2 shows current waveforms Iu, Iv, and Iw of the second three-phase winding connected to the double boosting rectifier circuit. The problem to be solved is that the current of the second three-phase winding connected to the double boost rectifier circuit in the rectifier circuit of the distributed power generator as described above is as shown in FIG. Since it is in an unbalanced state, the second three-phase winding in the permanent magnet generator 3 must be provided with different winding specifications, making the production complicated, and the current It is a point of causing vibration and noise due to unbalance.

The present invention has been made in view of the above circumstances, and a reactor is connected to the output terminals of the first and second three-phase windings insulated from each other of a permanent magnet generator driven by a wind turbine or a water turbine. In the distributed power generation apparatus that outputs the DC output obtained from each AC in parallel and outputs it to the outside, the first three-phase winding is connected to the full-wave rectifier circuit via the reactor, and the second three-phase The winding is connected to each phase voltage doubler rectifier circuit through the reactor for each phase, and the DC output terminal of each phase voltage doubler rectifier circuit is connected in series to be connected in parallel to the full wave rectifier circuit . The three three-phase windings are composed of windings that are insulated from each other, and each phase voltage doubler rectifier circuit includes a series diode in which the anode side and the cathode side of the diode are connected in series, and a capacitor in series. A series capacitor is connected in parallel to A voltage rectifier circuit, connected to the middle point of the series diode from one of the phase-insulated windings via the reactor, and the middle point of the series capacitor to the other point of the phase-insulated windings; Is a rectifier circuit of a power generator for a distributed power source.

In the rectifier circuit of the power generator for a distributed power source according to the present invention, since the output power is small, the second three-phase winding, which can be configured with a thin winding, passes through the reactor and each phase becomes a voltage doubler rectifier circuit. Because of the connection, the induced voltage of the second three-phase winding that can charge the battery 13 can be reduced to 1 / (2√3) of the conventional example even when the wind turbine speed N is low as in the conventional example. Moreover, the current does not become unbalanced.
Therefore, since it is not necessary to strengthen the withstand voltage of the second three-phase winding, the price of the power generator for the distributed power source can be reduced.

  A reactor is connected to the output terminals of the insulated first and second three-phase windings of the permanent magnet generator 3 driven by a windmill or a water turbine, and DC outputs obtained from the respective ACs are connected in parallel. The first three-phase winding is connected to the three-phase full-wave rectifier circuit via the reactor, and the second three-phase winding is connected to the reactor for each phase through the reactor. And a DC output terminal of each voltage doubler rectifier circuit connected in series and connected in parallel to the three-phase full-wave rectifier circuit.

FIG. 1 is a main circuit connection diagram of a power generator for a distributed power source driven by a windmill when the present invention is applied to the windmill.
In the figure, 17 is a first diode, 18 is a second diode, 19 is a series diode circuit, 82 is a second three-phase winding U-phase output terminal, 83 is a second V-phase output terminal, and 84 is The second W-phase output terminal, 71 is a first voltage doubler rectifier circuit, 72 is a second voltage doubler rectifier circuit, and 74 is a third voltage doubler rectifier circuit. The same reference numerals as in FIG. Represent.
Hereinafter, FIG. 1 will be described.

The AC output of the first three-phase winding is output to the battery 13 via the first three-phase winding output terminal 81, the reactor 4, and the three-phase full-wave rectifier circuit 61, as in the conventional example. Here, since the three-phase full-wave rectifier circuit 61 is used, the first three-phase winding can charge the battery 13 with √3 times the phase voltage.
The second three-phase winding includes first and second reactors 5 and DC connected in series from the second three-phase winding U-phase output terminal 82, V-phase output terminal 83, and W-phase output terminal 84. 2 and output to the battery 13 through the third voltage doubler rectifier circuits 71, 72 and 73.

The first voltage doubler rectifier circuit 71 includes a series diode circuit 19 in which the anode side of the first diode 17 and the cathode side of the second diode 18 are connected in series, and a series capacitor circuit 16 in which capacitors are connected in series. Connected in parallel to form a rectifier circuit. The middle point of the series diode circuit 19 is connected from one of the second three-phase winding U-phase output terminals 82 via the reactor 5, and the middle point of the series capacitor 16 is connected to the second three-phase winding U-phase output terminal 82. Are connected to each other. Since each capacitor of the series capacitor 16 is charged alternately on the + side or the − side of the phase voltage, the first voltage doubler rectifier circuit 71 is charged at twice the phase voltage.
Here, the DC voltage of each of the first capacitor 14 and the second capacitor 15 has a small voltage pulsation due to the size of the capacitor capacity, but is charged to half the voltage of the battery 13. Further, although not particularly shown, unlike the conventional example, a balanced current flows through the second three-phase winding of the present invention.

  The second voltage rectifier circuit 72 and the third voltage rectifier circuit 73 are similarly configured. By connecting the first, second, and third voltage doubler rectifier circuits 71, 72, and 73 in series, the second three-phase winding generates a voltage that is six times the induced voltage in each phase in total. Is equivalent to Therefore, for example, when the number of turns of each phase of the first three-phase winding and the second three-phase winding is equal, the output from the second three-phase winding is rotated by the wind turbine as compared with the first three-phase winding. The charging of the battery 13 is started from the rotational speed of 1 / (2√3) of the number N1.

  Further, when the number of turns of the second winding is 1 / √3 times the number of turns of the first winding, 1 / (2√3) × √3 = 1/2, and the wind turbine rotational speed N2 in FIG. Becomes a voltage that can be charged at 1/2 of the wind turbine rotation speed N1, and this distributed power generator starts charging the battery 13 at 1/2 of the wind turbine rotation speed N1 in FIG. The dielectric strength of the second winding can be suppressed to 1 / √3 times that of the first winding.

In the embodiment of the present invention shown in FIG. 1, the case of two types of windings of the permanent magnet generator 3 has been described. However, as the three types of windings, a double voltage is applied to the windings that start charging from a low wind turbine speed. A method of connecting a rectifier circuit is also possible.
With this configuration, the output to the constant voltage source such as the battery 13 of the distributed power generation device 2 can be made closer to the maximum output curve Pt of the windmill than in the case of two windings. A lot of energy can be acquired.

In addition, the reactor used in the present invention can be finely adjusted to match the wind turbine output characteristics by being a saturated reactor or tapped.
Furthermore, the reactor 4 in FIG. 1 can be omitted if the inductance in the permanent magnet generator 3 can be grasped at the design stage.

  According to the rectifier circuit of the power generator for a distributed power source of the present invention, the insulation withstand voltage of the winding that starts charging from a low windmill speed in the permanent magnet generator is insulated, and the insulation of the winding that starts charging from a high windmill speed. Since it can be reduced to half or less of the withstand voltage, an inexpensive rectifier circuit for a distributed power generator can be provided.

It is an Example of the present invention and is a diagram for explaining a rectifier circuit of a power generator for a distributed power source. It is a figure for demonstrating the electric current which flows into the 2nd 3 phase coil | winding of the permanent magnet type generator of the power generator for distributed power supplies of a prior application. It is a windmill rotation speed versus windmill output characteristic figure of the power generator for distributed power supplies which a prior application applies to. It is a figure explaining the outline | summary of a windmill rotation speed versus windmill output characteristic when a wind speed is made into a parameter. It is the main circuit connection diagram of the power generator for distributed power supplies of a prior application.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Windmill 2 Power generation apparatus for distributed power sources 3 Permanent magnet type generator 4 1st reactor 5 2nd reactor 61 3 phase full wave rectifier circuit 62 Single phase full wave rectifier circuit 71 1st voltage doubler rectifier circuit 72 2nd Voltage doubler rectifier circuit 73 Third voltage doubler rectifier circuit 74 Double voltage booster circuit 81 First three phase winding output terminal 82 Second three phase winding U phase output terminal 83 Second three phase winding V phase output Terminal 84 Second three-phase winding W-phase output terminal 85 Second three-phase winding output terminal 11 Positive output terminal 12 Negative output terminal 13 Battery 14 First capacitor 15 Second capacitor 16 Series capacitor circuit 17 First diode 18 Second diode 19 Series diode circuit

Claims (1)

A reactor is connected to the output terminals of the first and second three-phase windings insulated from each other of a permanent magnet generator driven by a wind turbine or a water turbine, and DC outputs obtained from the respective AC are connected in parallel. In the distributed power generator for output to the outside, the first three-phase winding is connected to the full-wave rectifier circuit via the reactor, and the second three-phase winding is phase-multiplied for each phase via the reactor. Connected to the voltage rectifier circuit, connected in series to the full-wave rectifier circuit of the DC output terminals of the phase doubled voltage rectifier circuits, and the second three-phase windings are insulated from each other. Each phase doubled voltage rectifier circuit comprises a series diode in which the anode side and the cathode side of the diode are connected in series, and a series capacitor in which a capacitor is connected in series, which are connected in parallel to each phase double voltage rectifier. The middle point of the series diode Is connected through the reactor from one of the respective phases insulated windings, the phase insulated winding the other connected thereto that the power generation device for a distributed power supply, wherein of the midpoint of the series capacitor Rectifier circuit.

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