WO2006011206A1 - Multiplex rectifier circuit - Google Patents

Abstract

A multiplex transformer capable of not only suppressing low order harmonic components sufficiently but also suppressing all harmonic components with good balance while suppressing an increase in size of a DC reactor passing a multiplexed DC current. Since the turn ratio of the multiplex transformer (10) is selected to be one that can not only suppress harmonics of a specified order but also suppress all harmonics with good balance and AC reactors (9, 7) are inserted in order to suppress harmonics furthermore, all harmonic components can be suppressed with good balance in addition to sufficient suppression of low order harmonic components while suppressing an increase in size of the DC reactor (3) passing a multiplexed DC current, and not only national regulations but also European regulations can be dealt with.

Description

 Specification

 Multiple rectifier circuit

 Technical field

 [0001] The present invention relates to a multiple rectifier circuit that converts a three-phase AC power source into a DC power source with less harmonic components.

 Background art

 [0002] The most common method for converting three-phase alternating current into direct current is to use a three-phase full-wave rectifier in which six rectifier elements are bridged. In this three-phase full-wave rectifier, the rectifying elements that are energized sequentially every 60 degrees are switched and a DC voltage is output, so the rectified DC voltage has a period of 6 times the power supply frequency and a large amplitude. A voltage lip nore is included. This becomes a harmonic and causes a bad influence on the equipment using the DC power supply.

 Therefore, for example, in Patent Documents 1 and 2, for a first rectifier circuit that converts a three-phase alternating current into a direct current, a multiplex circuit that transforms six multiplexing alternating voltages whose phases change from the three-phase alternating current power supply A transformer and a second rectifier circuit that converts the six AC voltages output from the multiple transformer to DC are provided, and the output DC voltage of the second rectifier circuit is multiplexed with the output DC voltage of the first rectifier circuit. Multiple rectifier circuits have been proposed that obtain a DC power supply with less harmonic components.

 [0004] As a multiple transformer, in Patent Document 1, an equilateral triangular transformer vector diagram showing the relationship between the three-phase AC R-phase, S-phase, and T-phase voltages remains around each vertex. A transformer that transforms a total of six phases of AC voltage located on an arc that divides the arc drawn by connecting the two vertices into three equal parts is shown.

[0005] In addition, Patent Document 2 discloses a transformer that outputs two types of three-phase alternating current by inputting three-phase alternating current and delaying the phase by an electrical angle of ± 20 ° as a multiple transformer. Specifically, this transformer is drawn by connecting the remaining two vertices around each vertex of the equilateral triangle in the equilateral triangle transformer vector diagram showing the relationship of the three-phase AC phase voltages. A straight line that passes through the two points obtained by dividing the arc into three equal parts and each vertex of the equilateral triangle, A transformer that satisfies the transformer vector diagram represented by the hexagon formed by each apex and a straight line parallel to one side, the first and second transformers mounted on the three-phase iron cores, respectively. A second coil, wherein one end of the first coil is connected to one end of the second coil having the same polarity and sequentially different phases, and the other end of the first coil has the same polarity, and the one end Are connected to the other ends of the second coils, which are sequentially different in different combinations, and each of a, b, c is a number of 2 or more, the number of the first coil is 2a, A first tap is provided, and the second coil has a number 2b + c, and a second tap is provided at an inner position by the number b from one end, and an inner position by the number b from the other end. A third tap is provided, and the first tap for three phases is used as an input terminal for a three-phase AC voltage. The second tap for 3 minutes is used as a first output terminal for a three-phase AC voltage, the third tap for three phases is used as a second output terminal for a three-phase AC voltage, and the ratio of the power a : b: c = sin20 °: sin40 °: sinl 20 ° is set, and the cross-sectional area of the conductor corresponding to the power c of the second coil is smaller than that of the other parts. It is a vessel.

 [0006] In this way, in the conventional multiple rectifier circuit, the harmonic ratio of the multiple transformer that transforms the 6 multiple AC voltages whose phases change from the three-phase AC power supply is devised to reduce the harmonic components. DC power supply is available.

 Patent Document 1: Japanese Patent Application Laid-Open No. 2002-10646

 Patent Document 2: JP 2004-120878 A

 Disclosure of the invention

 Problems to be solved by the invention

[0008] By the way, in the suppression of power supply harmonics, the fifth and seventh orders are most required for three phases. However, the standard value is not a measure of a specific order but has a good balance as a whole. It is demanded to suppress this.

[0009] However, in the conventional multiple rectifier circuit described above, the objective is to zero specific harmonic components centering on the low-order harmonics of the input current in principle. There is a problem that the wave component increases as compared with the case where no multiplexing measure is taken.

[0010] In addition, in the conventional multiple rectifier circuit, the power ratio of the multiple transformer selected in principle to suppress low-order harmonics is that the direct current reactor where the multiplexed direct current flows is not. Since it is assumed that a large direct current can be regarded as a direct current with no pulsating current, there is a problem that an increase in the loss of the DC reactor and the accompanying loss will occur in order to realize the effect.

 [0011] The present invention has been made in view of the above. While suppressing an increase in the size of a DC reactor through which multiplexed DC flows, low-order harmonic components are sufficiently suppressed and all harmonics are suppressed. An object is to obtain a multiple rectifier circuit capable of suppressing components in a well-balanced manner. Means for solving the problem

 In order to achieve the above-described object, the present invention includes a first rectifier circuit that converts a three-phase AC power source into a DC power source, a step-down voltage of the three-phase AC power source, and the three-phase AC power source. In the equilateral triangle transformer vector diagram showing the relationship between the phase voltages of the power supply, the arc connecting the second vertex and the second vertex around the first vertex of the equilateral triangle and the second and second A spatial position between the edges connecting the three vertices, the first spatial position separated by 20 degrees or more from the second vertex side and the second spatial position separated by 20 degrees or more from the third vertex side. Multiplexes that transform alternating voltages arranged at six spatial positions between the arcs connecting the remaining two vertices centered on each vertex and each side of the equilateral triangle so as to be located at the spatial location. A transformer and a second rectifier circuit for rectifying six AC voltages having different phases output from the multiple transformer The provided, characterized in that to obtain a multiple DC output said first and second rectifier circuits are connected in parallel.

 [0013] According to the present invention, it is possible to suppress all harmonic components in a well-balanced manner while sufficiently suppressing low-order harmonic components while suppressing an increase in the size of a DC rear tuttle through which multiplexed DC flows. it can.

 The invention's effect

 [0014] According to the present invention, not only the specific order but also the harmonic components can be suppressed in a well-balanced manner as a whole, so that it is possible to cope with not only domestic standards but also European standards.

 Brief Description of Drawings

FIG. 1 is a circuit diagram showing a configuration of an inverter circuit using a multiple rectifier circuit according to Embodiment 1 of the present invention. 2] It is a diagram for explaining an example of a winding structure of the multiple transformer shown in FIG.

 FIG. 3 is a transformer vector diagram illustrating an arrangement relationship of AC voltages transformed by the multiple transformer shown in FIG. 1.

FIG. 4] is a diagram showing a simulation result of the input current change in the case where the rectifier circuit shown in Patent Documents 1 and 2 does not use a multiple transformer.

5] FIG. 5 is a diagram showing the result of frequency analysis of the input current change shown in FIG.

 FIG. 6 is a diagram showing a simulation result of a change in input current in a rectifier circuit using multiple transformers described in Patent Documents 1 and 2.

7] FIG. 7 is a diagram showing the result of frequency analysis of the input current change shown in FIG.

FIG. 8] is a diagram showing a simulation result of a change in input current when a DC reactor is added to the rectifier circuit using the multiple transformers shown in Patent Documents 1 and 2. 9] FIG. 9 is a diagram showing the result of frequency analysis of the input current change shown in FIG.

 FIG. 10 is a diagram showing a simulation result of a change in input current when two AC reactors and a noise filter are excluded in the configuration shown in FIG.

11] FIG. 11 is a diagram showing the result of frequency analysis of the input current change shown in FIG.

 FIG. 12 is a diagram showing a simulation result of a change in input current when a noise filter is excluded in the configuration shown in FIG. 1 (configuration in which two AC rear tuttles exist). 13] FIG. 13 is a diagram showing the result of frequency analysis of the input current change shown in FIG.

14] A circuit diagram showing the configuration of an inverter circuit using a multiple rectifier circuit according to Embodiment 2 of the present invention.

15] A circuit diagram showing a configuration of an inverter circuit using a multiple rectifier circuit according to Embodiment 3 of the present invention.

Explanation of symbols

 1 Three-phase AC power supply

 2 First rectifier circuit

 3 DC reactor (second DC reactor)

4 Smoothing capacitor 7 AC rear turtle (first AC rear turtle)

 8 Noise filter

 9 AC reactor (second AC reactor)

 10 Multiple transformer

 11 First rectifier circuit

 12 DC Reactor (First DC Reactor)

 13 Inverter circuit rectifier circuit

 21 R phase iron core

 22 R phase first coinore

 23 R phase second coinore

 24 S phase iron core

 22 Phase S 1st coin

 23 S Phase 2 Coinole

 21 T-phase iron core

 22 T-phase first coil

 23 T-phase second coil

 31, 36 Spatial position where transforming AC voltage is placed

 A, B, C Structures (Power Harmonic Countermeasure Equipment)

 BEST MODE FOR CARRYING OUT THE INVENTION

 Hereinafter, a preferred embodiment of a multiple rectifier circuit according to the present invention will be described in detail with reference to the drawings.

 [0018] Embodiment 1.

FIG. 1 is a circuit diagram showing a configuration of an inverter circuit using a multiple rectifier circuit according to Embodiment 1 of the present invention. In FIG. 1, the inverter circuit generally constitutes a first rectifier circuit 2 that is a three-phase full-wave rectifier for a three-phase AC power source 1 and a smoothing circuit that smoothes the output DC voltage of the first rectifier circuit 2. Inverter that generates AC voltage by switching the terminal voltage (DC voltage) of DC capacitor 3 and smoothing capacitor 4 and smoothing capacitor 4 5, and the motor 6 is driven and controlled by the output AC voltage of the inverter 5.

 The multiple rectifier circuit according to the first embodiment (1) basically applies the voltage of the three-phase AC power source 1 to the first rectifier circuit 2 provided for the three-phase AC power source 1. Multiplexing transformer 10 that transforms six alternating voltages that are stepped down and different in phase, and rectifies the output alternating voltage of this multiple transformer 10, and multiplexes the rectified output to the rectified output of first rectifier circuit 2. The second rectifier circuit 11 is provided. A configuration example of the multiplex transformer 10 will be described later (Figs. 2 and 3). Similar to the first rectifier circuit 2, the second rectifier circuit 11 includes a diode bridge.

 [0020] (2) As an almost essential configuration, the AC rear tuttle 9 is provided at the input stage of the multiple transformer 10. The AC reactor 9 can be configured by the leakage inductance component of the multiple transformer 10.

 [0021] (3) Further, in order to further suppress power source harmonics, an AC rear tuttle 7 is directly connected to the output end of the three-phase AC power source 1, and the three-phase AC power source 1 is connected to each part via the AC rear tuttle 7. AC voltage · Ensure that an AC current is applied. (4) In addition, in order to reduce the power noise superimposed on the three-phase AC power source 1, the noise filter 8 is connected to the output terminal of the AC reactor 2 and the input terminal of the first rectifier circuit 2 and the AC reactor 9 Between.

 [0022] By these measures, while suppressing an increase in the size of the DC reactor 3 through which the multiplexed DC flows, low-order harmonic components are sufficiently suppressed, and all harmonic components are simply converted to the first rectifier. When only circuit 2 is used, that is, compared with a case where no multiplexing is performed, it becomes possible to suppress effectively. In FIG. 1, the circuit portion from the AC rear tutor 7 to the DC rear tuttle 3 surrounded by the broken line A is a lump having a connection end to the three-phase AC power source 1 and a connection end to the smoothing capacitor 4. Since it is a block, it can be handled as an independent structure (power harmonic countermeasure device).

 Next, a configuration example of the multiple transformer 10 will be described with reference to FIG. 2 and FIG. Figure

 FIG. 2 is a diagram illustrating an example of a winding structure of the multiplex transformer 10. FIG. 3 is a transformer outline diagram illustrating the arrangement relationship of the AC voltage transformed by the multiple transformer 10.

In FIG. 2, R-phase iron core 21 is equipped with R-phase first coil 22 and R-phase second coil 23. ing. Of these, the R-phase first coil 22 is labeled R7 and R6 at both ends, but an intermediate tap R is provided at a position that equally divides the power in a ratio of a: a. Further, in the R-phase second coil 23, intermediate taps S3 and T2 are provided at positions to divide the power factor having the symbols S7 and T6 at both ends at a ratio of b: c: b. One end R7 of the R-phase first coil 22 and one end S7 of the R-phase second coil 23 have the same polarity.

 The S-phase iron core 24 is equipped with an S-phase first coil 25 and an S-phase second coil 26.

 Among them, the S-phase first coil 25 is provided with a force S having a sign S7 and a sign S6 at both ends, and an intermediate tap S at a position that equally divides the power in a ratio of a: a. In addition, the S-phase second coil 26 is labeled T7 and R6 at both ends, but is provided with intermediate taps T3 and R2 at positions where the power is divided at a ratio of b: c: b. One end S7 of the S-phase first coil 25 and one end Τ7 of the S-phase second coil 26 have the same polarity.

 [0026] Furthermore, the first phase coil 28 and the second phase coil 29 are mounted on the phase iron core 27. Among these, in the first phase coil 28, an intermediate tap Τ is provided at a position that equally divides the force 卷 having the symbols Τ7 and Τ6 at both ends at a ratio of a: a. In addition, in the T-phase second coil 29, intermediate taps R3 and S2 are provided at positions at which the force coefficients having R7 and S6 at both ends are divided at a ratio of b: c: b. One end T7 of the T-phase first coil 28 and one end R7 of the T-phase second coil 29 have the same polarity.

 [0027] Then, one end R7 of the R-phase first coil 22 is connected to one end R7 of the T-phase second coil,

 The other end R6 of one coil 22 is connected to the other end R6 of the S-phase second coil 26. One end S7 of the S-phase first coil 25 is connected to one end S7 of the R-phase second coil 23, and the other end S6 of the S-phase first coil 25 is connected to the other end S6 of the T-phase second coil 29. One end T7 of the T-phase first coil 28 is connected to one end S7 of the S-phase second coil 26, and the other end T6 of the T-phase first coil 28 is connected to the other end T6 of the R-phase second coil 23. The power ratio a: b: c is, for example, 41:88:83.

 [0028] The multiplex transformer 10 is configured to have the above connection relationship, and the intermediate taps R, S, and T are input terminals, and are the R phase, S phase, and negative phase of the three-phase AC power source 1. Corresponding phase wires are connected. The intermediate taps S3, T2, T3, R2, R3, and S2 are output terminals and are connected to corresponding input terminals of the second rectifier circuit 11.

[0029] Transformer beta of 6 potentials taken from the intermediate taps S3, T2, T3, R2, R3, S2. Figure 3 shows the layout of the map. That is, the multi-transformer 10 adjusts the power ratio a: b: c shown in FIG. 2 and transforms the equilateral triangle indicating the phase relationship of the phase voltages of the three-phase AC power source 1 as shown in FIG. In the vector diagram, if the vertices of an equilateral triangle are R, S, and T, for example, between the arc connecting the remaining vertices S and T with the vertex R as the center and the side connecting the vertices S and T Centered on each vertex so that it is located at a first spatial position 31 that is more than 20 degrees away from the vertex S side and a second spatial position 32 that is more than 20 degrees away from the vertex T side. The AC voltage arranged at the six spatial positions 31 36 between the arcs connecting the remaining two vertices and each side of the equilateral triangle is transformed.

 [0030] In the multiple transformers shown in Patent Documents 1 and 2, as shown by the "X" mark in Fig. 3, the arc connecting the remaining two vertices around each vertex of the regular triangle is divided into three equal parts. The AC voltage placed at a position on the arc is transformed. That is, in the present invention, the power ratio a: b: c is different from the contents disclosed in Patent Documents 1 and 2. Therefore, the winding method of the multiple transformer 10 that generates the desired potential shown in FIG. 3 is not limited to the method shown in FIG. 2 as long as the power ratio a: b: c specified in the present invention is observed. For example, various methods disclosed in Patent Document 1 can be used.

 [0031] In the multiplex rectifier circuit configured as described above, when the phase voltage is expressed, the multiplex rectifier 10 2 is applied to the three-phase AC voltage shifted by 120 ° by the R phase, S phase, and T phase. The secondary voltage has a peak value that is lower than the R-phase, S-phase, and T-phase voltages, but has the highest voltage or the lowest voltage in the comparison. When the second rectifier circuit 11 is connected to the first rectifier circuit 2 and the second rectifier circuit 11 is connected to the first rectifier circuit 2, the second rectifier circuit 11 can flow in the period of the highest voltage or the lowest voltage.

 [0032] Compared with the case where only the first rectifier circuit 2 is used (that is, when no multiplexing is performed), the current passing period in the first rectifier circuit 2 is reduced. The conduction period of the second rectifier circuit 11 occurs. The current through the multiple transformer 10 is shunted to the R, S, and T phases on the primary side by the transformer connection. Therefore, the currents of the S and 近 phases as a whole are close to a sine wave with suppressed harmonics.

[0033] Note that the suppression effect tends to increase as the DC reactor 3 has a larger capacity and the smoothing capacitor 4 has a smaller capacity. In addition, AC reactors are actively used as power line components. By adding Tor 7, harmonics can be further suppressed as a whole. However, since all the input currents of the multiple rectifier circuit flow in this AC rear tuttle 7, the energization current increases and the size increases.

 [0034] Here, the harmonic suppression effect according to the present invention will be described in comparison with the effect obtained by the conventional techniques (Patent Documents 1 and 2). Fig. 4 and Fig. 9 explain the harmonic suppression effect obtained by the conventional technology (Patent Documents 1 and 2), and Figs. 10 to 13 show the harmonic suppression effect obtained by the present invention. Explains. Both are the results of evaluation by simulation. Noise filter 8 was excluded.

 [0035] The power ratio of the multiple transformers shown in Patent Documents 1 and 2 is that the six-phase AC voltage that is transformed is the rest of the remaining voltage centering on a certain apex as described in FIG. It is determined to be placed at a position on an arc obtained by dividing the arc connecting the two vertices into three equal parts. Patent Documents 1 and 2 show that the multiple ratio of the multiple transformers is the same as a result of the different expression methods. Here, the power ratio of multiple transformers is a: b: c = sin20 °: sin40 °: sinl 20 ° 43: 81: 109. This is shown in Patent Document 2. In Patent Documents 1 and 2, the AC reactors 7 and 9 shown in FIG. 1 are not shown, and there is no description that suggests their existence.

 [0036] In the simulation, the AC reactors 7 and 9 shown in Fig. 1 are not present, the voltage of the three-phase AC power source 1 is set to 400V'50Hz between phases, and the capacities of the DC reactor 3 and the smoothing capacitor 4 are about 8kW. The load was 7900W with a typical 2.9mH and 1650uF (assuming two series of 3300uF capacitors in series).

 [0037] FIG. 4 is a diagram showing a simulation result of a change in input current when a multiple transformer is not used in the rectifier circuit shown in Patent Documents 1 and 2. FIG. 5 is a diagram showing the frequency analysis result of the input current change shown in FIG. In FIG. 1, the three-phase AC power source 1 is directly connected to the first rectifier circuit 2 and there is no route for the AC reactor 9, the multiple transformer 10, and the second rectifier circuit 11. In Fig. 5, the power supply frequency (50 Hz) is shown at the left end, and from this point to the right, the harmonics are shown in order from the lowest order.

[0038] FIG. 6 is a diagram showing a simulation result of the input current change in the rectifier circuit using the multiple transformer disclosed in Patent Documents 1 and 2. FIG. FIG. 7 is a diagram showing the result of frequency analysis of the input current change shown in FIG. In Figure 1, the three-phase AC power source 1 is directly connected to the first In addition to being connected to the rectifier circuit 2, the multiple transformer 10 and the second rectifier circuit 11 are connected to the first rectifier circuit 2 in parallel. As shown in Figs. 6 and 7, when multiple transformers are used, the harmonic suppression effect appears. However, low-order harmonics cannot be said to be sufficiently reduced as expected in Patent Documents 1 and 2. Here, the 17th and 19th orders are 5.85% and 3.87% of the fundamental wave, respectively.

 [0039] FIG. 8 is a diagram showing a simulation result of a change in input current when a DC reactor is added to the rectifier circuit using the multiple transformers disclosed in Patent Documents 1 and 2. FIG. 9 is a diagram showing the result of frequency analysis of the input current change shown in FIG. When 10mH of DC rear tuttle, which is not taken into account in Patent Documents 1 and 2, is added, the result is as shown in Fig. 8 and Fig. 9, and the lower harmonic components such as the fifth order are suppressed. Are 5.25% and 4.27% of the fundamental wave, respectively.

 [0040] Now, the power ratio of the multiple transformer 10 according to the present invention is such that the transformed six-phase AC voltage is expressed as a transformer vector as described in FIG. The spatial position between the side of the equilateral triangle connecting the three phase potentials of the phase and T phase with a straight line, and the arc drawn by connecting the remaining two vertices with each vertex at the center. Adjustments are made so that the angle between the triangle and the side of the triangle is greater than 20 °. Here, as an example, the power ratio &: 3 = 41: 88: 83 shown in FIG. 2 is adopted. This power ratio a: b: c = 41: 88: 8 3 is 0.994 when one side of the equilateral triangle is 1 as the line voltage, and the spatial position is equivalent to 22 degrees with respect to the side. Show that the AC voltage is transformed.

 [0041] Similar to the above-described conventional technology, the simulation is performed by setting the voltage of the three-phase AC power source 1 to 400 V · 50 Hz between phases, and the capacity of the DC reactor 3 and the smoothing capacitor 4 to be 2 9mH and 1650uF (assuming two series of 3300uF capacitors in series) were used with a load of 7900W.

FIG. 10 is a diagram showing a simulation result of the input current change in the configuration shown in FIG. 1 when two AC reactors and a noise filter are excluded. FIG. 11 is a diagram showing the result of frequency analysis of the input current change shown in FIG. As shown in Fig. 10 and Fig. 11, the low-order harmonic components are kept low overall, and the remaining 17th and 19th orders are 4.74% and 3.62% of the fundamental wave, respectively. It has become. [0043] With regard to suppression of power supply harmonics, fifth-order and seventh-order suppression is most required in three phases, but the overall balance is also required as a standard value. For example, in the case of domestic specific customer response, the target value for the remaining harmonics is 6.6kV power reception, and the upper limit current value power per lkW for the entire power receiving equipment 5th order = 3.5mA, 7th order = 2. 5mA, 11th = 1.6 mA, 13th = 1.3mA, 17th = 1. OmA, 19th = 0.9mA, 23rd = 0.76mA, 23rd order = 0.7mA Yes.

 [0044] Also, in the European standard IEC_61000_3_2, if the power of 16AZ phase or less is extracted, the upper limit of the residual harmonics of each order of the individual equipment is the absolute value, 5th order = 1.14A, 7th order = 0.77A 11th order 0.33A, 13th order = 0.21A, 15 39th order (odd number) = 0.15 X (15 / n). N is the order.

 [0045] As described above, according to the standard, it is required to suppress harmonics in a well-balanced manner as a whole rather than measures against only a specific order. As shown in FIGS. 12 and 13, this can be realized by selecting the power ratio of the multiple transformer as in the present invention, and is particularly effective when the AC reactor 9 and the AC reactor 7 are used together. is there.

 FIG. 12 is a diagram showing a simulation result of the input current change when the noise filter is excluded from the configuration shown in FIG. 1 (a configuration in which two AC rear tuttles are present). FIG. 13 is a diagram showing the result of frequency analysis of the input current change shown in FIG. Figures 12 and 13 can also satisfy the above IEC_61000_3_2, which is the simulation result when AC reactor is 9 = 3.7 mH and AC reactor is 7 = 4.5 mH.

 [0047] This has the effect of suppressing harmonic components in a balanced manner in the multiplex transformer 10 in advance, in particular, the effect of keeping the 17th and 19th orders low, and the AC reactor 9 This is due to the effect of actively suppressing the harmonic components (specifically, the 17th and 19th components) due to the stepped current of the multiplex transformer 10.

Thus, the power ratio of the multiple transformer 10 is 0.994 when one side of an equilateral triangle is 1 as the line voltage in this invention, and corresponds to, for example, 22 ° in angle from the side. By selecting the AC voltage to be transformed in the spatial position, the variation in remaining harmonics is suppressed even if there is manufacturing variation, and compared to the case where all harmonic components are not multiplexed, It is possible to respond to various regulations. Then, by introducing AC Reactor 7, further harmonic residual quantity Can be reduced.

 [0049] According to the power ratio adopted by the present invention, the energization angle in the first rectifier circuit 2 is increased as compared with the conventional techniques (Patent Documents 1 and 2). The current duty of the second rectifier circuit 11, and thus the multiple transformer 10, is reduced, and the effect of keeping the current capacity low can also be expected.

 [0050] In the above-mentioned specific simulation example, the same tendency is observed with the 200V power source shown as the 400V power source. In this example, the capacity of the DC reactor 3 was not changed, but by increasing the capacity, low-order harmonic components can be suppressed. Waves can be reduced. In particular, since the main current flows through the AC reactor 7, it is desirable to reduce the capacity as much as possible to prevent an increase in loss. In the specific simulation example above, the capacity of the AC reactors 7 and 9 can be selected depending on the maximum capacity of the power equipment that is considered to satisfy IEC_61000_3_2 up to an input current of 16A / phase (about 10.5kW). There is a possibility that the capacity can be selected.

 [0051] By the way, when sufficient harmonic suppression is required in the standard state as a product, the multiple rectifier circuit shown in Fig. 1 is always connected from the time of shipment. , Multiple transformer 10, first rectifier circuit 2, second rectifier circuit 11, DC rear tuttle 3, AC rear tutor 7, and noise filter 8 if necessary Thus, it is possible to suppress thermal stress on the electronic components such as the smoothing capacitor 4, the inverse converter 5 and the control circuit thereof arranged in the subsequent stage of the rectifier circuits 2 and 11. Needless to say, the parts to be used as the separate structure (power harmonic countermeasure device) A need not be all of the above parts, but may be selected as appropriate according to the requirements of the product structure.

 [0052] Thus, according to Embodiment 1, the power ratio of the multiple transformer is selected not only to a specific order but also to a power ratio that can suppress harmonics in a balanced manner as a whole, and further harmonics. In order to suppress this, AC reactors were also introduced, so that all harmonic components were suppressed while sufficiently suppressing low-order harmonic components while suppressing the increase in size of the DC reactor through which the multiplexed DC flows. Can be controlled in a well-balanced manner, and will be able to meet not only domestic standards but also European standards.

 [0053] Embodiment 2.

FIG. 14 shows an inverter circuit using a multiple rectifier circuit according to Embodiment 2 of the present invention. It is a circuit diagram which shows a structure. In FIG. 14, components that are the same as or equivalent to the components shown in FIG. 1 (Embodiment 1) are assigned the same reference numerals. Here, the description will focus on the parts related to the second embodiment.

That is, as shown in FIG. 14, in the second embodiment, a DC reactor whose parallel connection end and one end of the first rectifier circuit 2 and the second rectifier circuit 11 are connected to the smoothing capacitor 4 is used. Between the other end of 3, a direct current reactor 12 is arranged. That is, in the second embodiment, the DC reactor is divided into a DC reactor, a DC reactor 3 and a DC reactor 12.

 [0055] The DC rear tuttle 12 is not necessarily required, but is arranged because it is effective to increase the L value of the DC rear tuttle in order to improve the harmonic suppression level. According to this configuration, the circuit part (AC reactor 9, multiple transformer 10, second rectifier circuit 11, DC reactor 12) surrounded by broken line B in the figure is set as a separate structure (power harmonic countermeasure device). Therefore, it can be configured to be retrofitted.

 [0056] In other words, power supply harmonic countermeasures are usually sufficient only with DC reactor 3, and when additional countermeasures are selectively introduced, specifically, to specific customer guidelines for power supply harmonics. If a response is required, it can be dealt with by retrofitting another structure (power harmonic countermeasure device) B. In this way, it is possible to suppress the increase in size, weight, and cost of standard specification products.

 Note that specific circuit constant examples are as follows. However, as with the first embodiment, the capacity of the DC reactor and capacitor is assumed to be about 8kW. When the interphase voltage of the three-phase AC power source 1 is 200V, the L value of the sum of the DC rear tutor 3 and the DC rear tutor 12 is 0.5mH, the capacity of the smoothing capacitor 4 is 3300uF, and the L value of the AC rear tuttle 9 is 0. Set to 5mH.

 [0058] When the interphase voltage of the three-phase AC power source 1 is 400V, the L value of the inlet of the DC reactor 3 and the DC reactor 12 is 2.9mH, the capacity of the smoothing capacitor 4 is 1650uF, and the AC The L value of the rear tuttle 9 is 1. OmH.

[0059] As described above, according to the second embodiment, the same operation and effect as those of the first embodiment can be obtained, and the increase in size, weight, and cost of standard specification products can be suppressed. be able to. [0060] Embodiment 3.

 FIG. 15 is a circuit diagram showing a configuration of an inverter circuit using a multiple rectifier circuit according to Embodiment 3 of the present invention. In FIG. 15, components that are the same as or equivalent to the components shown in FIG. 14 (Embodiment 2) are assigned the same reference numerals. Here, the description will focus on the parts related to the third embodiment.

 That is, in FIG. 15, the rectifier circuit 13, the direct current reactor 3, the smoothing capacitor 4, and the inverse converter 5 are general inverter circuits. In the third embodiment, as shown in FIG. 15, the three-phase AC power source 1 side AC rear tuttle 7 to noise filter 8, the first rectifier circuit 2, the AC rear tuttle 9, the multiple transformer 10, the second rectifier circuit 11 and DC Reactor 11 are prepared as separate structures (power supply harmonic countermeasure device) C so that the external connection end of DC Reactor 11 and the reference potential connection end can be connected to the input of rectifier circuit 13 of the inverter circuit. ing.

 [0062] However, with respect to the diode that is a component of the rectifier circuit 13, when the power supply harmonic countermeasure device C is inserted, the duty of current flow concentrates on two specific diodes. Installed capacity · It is necessary to design heat dissipation.

 [0063] Regarding the DC rear tuttle, in this third embodiment, since the DC rear tuttle 12 is arranged in series with respect to the DC rear tuttle 3, the setting of the circuit constants is the same as in the second embodiment. become.

 As described above, according to the third embodiment, the power harmonic countermeasure device C is simply additionally inserted between the three-phase AC power source 1 and the rectifier circuit input unit of the inverter circuit. As a result, the effect of facilitating retrofit can be obtained. In the third embodiment, the application example to the second embodiment is shown. However, the structure A shown in the first embodiment (Fig. 1) is also a three-phase AC power source 1 as a power supply harmonic countermeasure device. Can be retrofitted between the inverter circuit and the rectifier circuit input of the inverter circuit.

Incidentally, in the first to third embodiments, the case where the present invention is used for the rectifying portion of the inverter circuit has been described, but it is needless to say that the same configuration can be used for other DC loads. The load is not particularly limited. However, in large equipment, the rectifier circuit is generally a diode rectifier circuit that does not have a regenerative converter. Source harmonic countermeasure device c, etc., post-additional force p.

 [0066] As a preferred application example of the present invention, it can be cited that it is used as a rectifier circuit of an air conditioner. That is, the motor 6 shown in FIGS. 1, 14, and 15 is a compressor motor in the air conditioner. In air conditioners, power inverters are often regarded as a problem because of the high inverter conversion rate of products and the high capacity occupancy rate of power equipment. A compressor motor driven by an inverter in an air conditioner is a suitable application because it has low inertia and is unlikely to generate regenerative energy. In addition, the air conditioner generally includes a fan for heat exchange around the inverter circuit, and when the multiple transformer section of the present invention is cooled, the airflow can be used, so no additional parts are required. There are also advantages.

 Industrial applicability

[0067] As described above, the multiple rectifier circuit according to the present invention is useful as a rectifier circuit that can support not only domestic standards but also European standards, and in particular, as a rectifier circuit that can flexibly respond to required levels. Is preferred.

Claims

The scope of the claims  [1] a first rectifier circuit that converts a three-phase AC power source into a DC power source;  In the equilateral triangle transformer vector diagram that reduces the voltage of the three-phase AC power source and shows the relationship between the phase voltages of the three-phase AC power source, the remaining first center is the first vertex of the equilateral triangle. A first space that is 20 degrees or more away from the second vertex side between the arc connecting the second and third vertices and the side connecting the second and third vertices. Between the arc that connects the remaining two vertices with each vertex as the center and each side of the equilateral triangle so that it is located at the second spatial position that is 20 degrees or more away from the third vertex side. A multiple transformer for transforming an alternating voltage arranged at six spatial positions;  A second rectifier circuit that rectifies six AC voltages with different phases output by the multiple transformer,  A multiple rectifier circuit, wherein the first and second rectifier circuits are connected in parallel to obtain a multiple DC output. [2] The multiple rectifier circuit according to [1], wherein an AC rear tuttle is disposed between the three-phase AC power source and the multiple transformer. [3] a first AC reactor that is connected to a three-phase AC power source, and a second AC reactor that is connected to the output end of the first AC reactor,  A first rectifier circuit for converting the three-phase AC power source to a DC power source via the first AC rear tutor;  In the equilateral triangle transformer vector diagram showing the relationship between the phase voltages of the three-phase AC power supply, the voltage of the three-phase AC power supply inputted from the second AC reactor is stepped down. A spatial position between an arc connecting the remaining second and third vertices with the first vertex as the center and a side connecting the second and third vertices, from the second vertex side An arc connecting the remaining two vertices with each vertex as a center so that the first spatial position is separated by 20 degrees or more and the second spatial position separated by 20 degrees or more from the third vertex side. A multiple transformer for transforming an alternating voltage arranged at six spatial positions between each side of the equilateral triangle; The second rectifier circuit rectifies six AC voltages with different phases output from the multiple transformer. Road, and  A multiple rectifier circuit, wherein the first and second rectifier circuits are connected in parallel to obtain a multiple DC output. [4] The multiple adjustment according to claim 3, wherein a noise filter is disposed between the first AC reactor and the first rectifier circuit and the second AC reactor. Flow circuit.  [5] A DC reactor that constitutes a smoothing circuit that performs a smoothing process on the multiple DC outputs is separated from a smoothing capacitor and connected to a parallel connection terminal of the first and second rectifier circuits, and the first AC 4. The multiple rectifier circuit according to claim 3, wherein each element from a rear tuttle to the DC rear tuttle constitutes an independent structure.  [6] The direct current reactor constituting the smoothing circuit that performs the smoothing process on the multiple direct current outputs includes the first direct current reactor having one end connected to a parallel connection end of the first and second rectifier circuits, A second DC reactor connected between the other end of the first DC reactor and a smoothing capacitor, the second AC reactor, the multiple transformer, the second rectifier circuit, and the first 4. The multiple rectifier circuit according to claim 3, wherein the direct current rear tuttle constitutes an independent structure.  [7] The other end of the DC reactor whose one end is connected to the parallel connection ends of the first and second rectifier circuits and the reference potential end are connected to the rectifier circuit input section of the inverter circuit. Item 4. The multiple rectifier circuit according to Item 1.  [8] The other end of the DC reactor whose one end is connected to the parallel connection ends of the first and second rectifier circuits and the reference potential end are connected to the rectifier circuit input section of the inverter circuit. Item 4. The multiple rectifier circuit according to Item 3.