JP2000165173A - Line noise filter and power converter using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To minimize a filter and to suppress noise by constituting structuring material of a magnetic core to constitute the filter of Fe based soft magnetic alloy and specifying dimension of a crystal grain to constitute the Fe base soft magnetic alloy and existence ratio of system with specified grain diameter. SOLUTION: A noise filter is provided with the crystal grains whose average of the grain diameter measured by maximum dimension is equal to or less than 50 nm and is a line noise filter constituted by using the magnetic core constituted of the Fe based soft magnetic alloy in which the crystal grains occupies at least 50% of the system. Capacitors 21, 22, 23 are connected between power lines on the input side of the filter. The capacitors are preferably connected between respective lines on the output side of the line noise filter and in addition, at least one crystal grain micronization element which is selected from a group consisting of Si and/or B, Cu, Nb, Ta, W, Mo, Zr, Hf, V and Ti is preferably included in the Fe based magnetic alloy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an EMI (Electro-Magnetic Interface) inserted into a power supply line of a power converter.
The present invention relates to a line noise filter for countermeasures (rence) and a power conversion device such as an inverter, a DC-DC converter, and a switching power supply using the same.

[0002]

2. Description of the Related Art Power conversion devices such as inverters, DC-DC converters, and switching power supplies have rapidly become widespread as semiconductor switching devices have become more sophisticated. In particular, with the development of high-output semiconductor switch elements for high frequencies represented by IGBTs and MOS-FETs,
High-capacity power converters are rapidly increasing in frequency, including low-noise inverters whose switching frequency is equal to or higher than the upper limit of the audible frequency band.

[0003] With the spread of such power converters, high frequency noise generated by the switching operation of the semiconductor switch elements is propagated to the power supply line and causes other electronic devices connected to the same power supply line to be damaged. There's a problem. Therefore, a line noise filter is inserted between the power supply and the power converter that drives the load, and the high-frequency noise is sufficiently suppressed so as to suppress the high-frequency noise transmitted from the device performing the switching operation to the power supply line. If not, a method of further inserting a zero-phase reactor between the power converter and the load is generally adopted.

FIG. 4 shows a circuit configuration of a conventional line noise filter. The line noise filter includes input terminals 11, 12, 13 connected to a power supply, input side power supply line capacitors 21, 22, 23, common mode choke coil 31, and output side power supply line capacitor 4.
1, 42, 43, capacitor 5 between power supply line and ground
1, 52, 53, output terminal 6 connected to the power converter
1, 62, 63, ground terminal 7 connected to ground
One. The common mode choke coil 31 has a high permeability Mn-Zn ferrite core, a wound core using a high permeability Co-based amorphous soft magnetic alloy ribbon, or a structure described in JP-A-3-19303. At least 5
A wound core using a Fe-based soft magnetic alloy ribbon containing crystal grains having a body-centered cubic lattice structure having an average particle diameter of 0 nm or less measured at 0% in a maximum dimension is used.

[0005]

SUMMARY OF THE INVENTION In order to suppress the generation of harmonic current, which is a drawback of a low-noise type high-frequency inverter using an IGBT or a capacitor input type rectifier circuit used in ordinary power supply equipment, an active-type inverter is used.
For devices that generate high levels of harmonic noise, such as switching power supplies with filters, FCC (United States Federal Communications Commission) Part 15, FTZ VDE
(German Electrician Association of Germany) 0871, V
In order to satisfy noise standards such as the CCI (Voluntary Control Council for Interference by Information Processing Equipment) or CISPR (International Special Committee on Radio Interference), noise in the low-frequency region specified by the above standards is reduced to below the standard value. To increase the inductance of the common mode choke coil 31 or to provide a capacitor 5 between the power supply line and the ground.
It is necessary to increase the capacity of 1, 52 and 53.

However, if the capacitances of the capacitors 51, 52, 53 between the power supply line and the ground are increased, the leakage current flowing from each line to the ground naturally increases. Since this leakage current leads to an electric shock, for example, it is regulated to be 1 mA or less in general electric equipment by the Electrical Appliance and Material Control Law. Therefore, in the conventional line noise filter, the capacitors 51, 5
Since the capacitances 2 and 53 are limited by the specified value of the leakage current, the inductance of the common mode choke coil 31 must be increased, and the common mode choke coil 31 becomes large, resulting in a large line noise filter. There was a problem of becoming. Also, noise suppression was not sufficient.

[0007]

According to a first aspect of the present invention, there is provided crystal grains having an average grain size of 50 nm or less measured at the largest dimension,
A line noise filter using a magnetic core composed of an Fe-based soft magnetic alloy in which the crystal grains occupy at least 50% of the structure, wherein a capacitor is connected between each line on the input side of the line noise filter. A line noise filter.

In order to further improve the noise suppression effect in the high frequency region, it is preferable to connect a capacitor between the lines on the output side of the line noise filter, and the Fe-based soft magnetic alloy is made of Si and / or Or B and C
u, Nb, Ta, W, Mo, Zr, Hf, V and Ti
And at least one crystal grain refining element selected from the group consisting of:

With the above-described configuration, the FCC Part 15, the FTZ VDE 0 using a small number of parts and a small common mode choke coil can be used.
871, VCCI or CISPR can satisfy the standard value in the low frequency region in the noise standard, and the line noise filter can be downsized. Moreover, since a capacitor between the power supply line and the ground is not used, the leakage current can be extremely reduced, which is preferable.

A second invention is a power converter having the line noise filter of the first invention on a power supply line side. Further, it is preferable that a zero-phase reactor is provided on the load side of the power conversion device because high-frequency noise can be suppressed. Here, the zero-phase reactor contains Si and / or B and at least one crystal grain refinement element selected from the group consisting of Cu, Nb, Ta, W, Mo, Zr, Hf, V and Ti. When a magnetic core composed of an Fe-based soft magnetic alloy having crystal grains having an average particle diameter of 50 nm or less measured at the largest dimension and the crystal grains occupying at least 50% of the structure is used, the zero-phase reactor becomes Since the size can be reduced, the size of the power converter can be reduced, which is preferable.

[0011] The power converter, characterized in that the line noise filter of the present invention is inserted on the power supply line side of the power converter, satisfies the noise standard despite its small size and low leakage current. It is preferable. A power converter in which a zero-phase reactor is inserted on the load side of the power converter is preferable because it can effectively suppress noise particularly in a frequency range of the MHz band or higher.

[0012]

Embodiments of the present invention will be described below in detail, but the present invention is not limited to these embodiments. (Embodiment 1) A line noise filter 2 was inserted in the power supply line side of an inverter having a rated capacity of 1.2 kVA and a single-phase AC 200 V input for driving a three-phase induction motor having an output of 400 W, and the noise terminal voltage was reduced as shown in FIG. CISPR Pu
A mounting test was performed to determine whether the specified value of b.11 was satisfied. In this mounting test, an inverter corresponds to the power converter 3 in FIG. 2 and a three-phase induction motor corresponds to the load 4. The inverter is an IPM using IGBT.
(Intelligent Power Module) with basic frequency 17
A switching operation of kHz is performed.

As the line noise filter, a line noise filter having the circuit configuration shown in FIG. 1 was used. FIG.
Input side inter-line power line capacitors 21, 22 and 23
Used a metallized polyester film capacitor having a capacitance of 0.22 μF.

The common mode choke coil 3 shown in FIG.
1 has a width of 15 m with a different composition manufactured by the single roll method.
m, a toroidal wound core having an outer diameter of 42 mm, an inner diameter of 25 mm, and a height of 15 mm was manufactured using an amorphous soft magnetic alloy ribbon having a thickness of about 20 μm, and then the wound core was heat-treated at a crystal grain refinement temperature. Thereafter, a wound core containing crystal grains having a body-centered cubic lattice structure with an average particle size measured at the largest dimension of 50 nm or less, which is manufactured by slow cooling, is
Insert it into an insulation case made of ethylene terephthalate,
From the top of the insulator case, # 1 to # 11 in which a copper wire having a wire diameter of 1.4 mm coated with a polyurethane insulating coating was wound 15 turns for each phase was used.

For the common mode choke coil 31 shown in FIG. 1, as a comparative example, an amorphous soft magnetic alloy ribbon having a width of 15 mm and a thickness of about 25 μm and having a different composition manufactured by a single roll method was used. The dimensions and structure are the same as those of # 1 to # 11 except that a toroidal-shaped wound core is manufactured, the wound core is heat-treated at a crystallization temperature or lower, and then slowly cooled. #A and #B, and Mn
-The dimensions and structure are the same as those described above except that a Zn ferrite core is used.
The case where #C having the same structure as # 1 to # 11 was used was also examined.

Table 1 shows the measurement results of the noise terminal voltage. In Table 1, the noise terminal voltage was particularly large 1
The comparison was made at frequencies of 50 kHz, 1.7 MHz, 4 MHz, and 10 MHz.

[0017]

[Table 1]

According to the present invention, CISPR Pub. 1
1 Class A noise terminal voltage standard of 150
79dBμV or less from 500kHz to 500kHz, 500k
From 30 Hz to 30 MHz, it is possible to satisfy 73 dBμV or less.
It can be seen that there is a margin of BμV or more.

On the other hand, the comparative example using #A has a frequency of 150 kHz as shown in Table 1, and the comparative example using #C has 150 kHz and 4 MHz as shown in Table 1.
In each case, the standard of the noise terminal voltage could not be satisfied.

In the comparative example using #B, the standard of the noise terminal voltage could be satisfied. However, after the inverter was operated continuously for 1000 hours, the noise terminal voltage was measured again. The noise terminal voltage at the frequency of could not satisfy the standard value. Investigation of this cause revealed that the inductance of coil #B was lower than the value immediately before the start of continuous operation.
It was found that the reason was that it was reduced to 1/4.
Therefore, it was found that #C could not be used due to the problem of aging. When other coils other than #B were used, there was no such a problem with time.

Therefore, using each coil except #C, FIG.
The line noise filter having the configuration shown in FIG.
Table 2 shows the results of measuring the noise terminal voltage in the same manner as
Shown in Note that the input side power supply line capacitor 2 shown in FIG.
1, 22, 23 and output side power line capacitor 4
Metallized polyester film capacitors having a capacitance of 0.22 μF were used for 1, 42 and 43, and ceramic capacitors having a capacitance of 4,700 pF were used for a capacitor between the power supply line and the ground.

In the comparative examples shown in Table 2, the frequency 1
It can be seen that the standard of the noise terminal voltage cannot be satisfied at 50 kHz. In the case where # 1 to # 11 are used, the line noise filter of the present invention having the configuration of FIG. 1 has a lower noise terminal voltage especially in a low frequency region than the comparative example having the configuration of FIG. As can be seen from Tables 1 and 2, the difference is as large as 10 dBμV.

[0023]

[Table 2]

(Embodiment 2) Single-phase 200V AC input for driving a three-phase induction motor with an output of 400W, rated capacity 1.2kV
A line noise filter 2 is inserted on the power supply line side of the inverter A and a zero-phase reactor 5 is inserted on the three-phase induction motor side as a load, and the noise terminal voltage becomes C as shown in FIG.
A mounting test was performed to determine whether the specified value of ISPR Pub.11 was satisfied. In this mounting test, the inverter and the load 4 correspond to the power converter 3 in FIG.
It is a phase induction motor. The inverter performs a switching operation at a fundamental frequency of 17 kHz by an IPM (Intelligent Power Module) using an IGBT.

As the line noise filter, a line noise filter having the circuit configuration shown in FIG. 1 was used as in the first embodiment. As the capacitors 21, 22 and 23 between the input-side power supply lines in FIG. 1, metalized polyester film capacitors having a capacitance of 0.22 μF were used. Also, the common mode choke coil 31 of FIG.
# 1 used in Example 1 was used.

As the zero-phase reactor 5, an amorphous soft magnetic alloy ribbon having a width of 15 mm and a thickness of about 20 μm and having a different composition manufactured by a single roll method is used, and a toroidal shape having an outer diameter of 60 mm, an inner diameter of 45 mm and a height of 20 mm is used. After the core was manufactured, the core was heat-treated at a crystal grain refining temperature, and then gradually cooled.
A core wound with crystal grains having a body-centered cubic lattice structure of 0 nm or less is inserted into an insulator case made of polyethylene terephthalate, and an inverter and a three-phase induction motor are connected from above the insulator case. A toroidal wound core was manufactured using an amorphous soft magnetic alloy ribbon having a width of 15 mm and a thickness of about 25 μm manufactured by a single roll method using # 21 to # 31 wound around the output cable for 4 turns. Except for using a wound core manufactured by heat-treating the wound core at a temperature lower than the crystallization temperature and then gradually cooling, the dimensions and structure are the same as those of # 21 to # 31 using the same #D and Mn-Zn ferrite core. Other than the above, #E having the same size and structure as those of # 21 to # 31 was used.

The common mode choke coil 31 has #
1 and the zero-phase reactor 5 is not used, the zero-phase reactor 5 is replaced with # 21 to # 31, #D and #E.
Table 3 shows the measurement results of the noise terminal voltage when using.
In Table 3, the noise terminal voltage was compared at frequencies of 150 kHz, 1.7 MHz, 4 MHz, and 10 MHz, which were particularly large. In Table 3, the name of the zero-phase reactor is indicated as “none” by the zero-phase reactor 5.
Is the result when not using.

As can be seen from Table 3, the zero-phase reactor 5
It can be seen that the noise terminal voltage can be reduced at all four frequencies by inserting, and the reduction effect is particularly large at 1.7 MHz and 4 MHz. Further, when zero-phase reactors # 21 to # 31 formed using a wound magnetic core including crystal grains having a body-centered cubic lattice structure having an average particle diameter measured at the largest dimension of 50 nm or less are used. CI
SPR Pub. 11 CLASS B 66 dBμV or less at 150 kHz which is the standard of the noise terminal voltage of 500, 500
It can be seen that the standard value of 56 dBμV or less can be satisfied from kHz to 30 MHz.

[0029]

[Table 3]

In this embodiment, after a core having a predetermined shape is manufactured as a core containing crystal grains having a body-centered cubic lattice structure with an average particle diameter measured at the maximum dimension of 50 nm or less, The case where the wound core is manufactured by heat-treating the core at a crystal grain refining temperature and then gradually cooling is described, but the heat treatment is performed while applying a magnetic field in a direction perpendicular to the magnetic path of the core. It goes without saying that the same effect can be obtained in the case of a magnetic core having a reduced squareness ratio in the magnetic characteristics.

In the present embodiment, the soft magnetic alloy ribbon constituting the wound core containing crystal grains having a body-centered cubic lattice structure having an average particle size measured at the largest dimension of 50 nm or less is used. Was about 20 μm, but 30 μm
If the plate thickness is less than m, there is no influence of the eddy current which may impair the function of the common mode choke coil or the zero-phase reactor.

[0032]

As described above, the use of the line noise filter of the present invention makes it possible to provide a small, high-performance, highly stable device having high noise attenuation characteristics over a wide frequency band. A high line noise filter can be realized, and a larger noise attenuation effect can be obtained by adding a zero-phase reactor.In addition, the power converter using the line noise filter of the present invention has a small size, low leakage current and noise. Practical effects are extremely large, such as the ability to meet standards.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a circuit configuration of a line noise filter according to the present invention.

FIG. 2 is a block diagram showing a connection configuration of a power supply, a power conversion device, and a load when a line noise filter is inserted.

FIG. 3 is a block diagram showing a connection configuration of a power supply, a power conversion device, and a load when a line noise filter and a zero-phase reactor are inserted.

FIG. 4 is a block diagram showing a circuit configuration of a conventional line noise filter.

FIG. 5 is a block diagram showing a connection configuration of a power supply, a power conversion device, and a load when a line noise filter and a zero-phase reactor are not inserted.

[Explanation of symbols]

1: power supply 2: line noise filter 3: power converter 4: load 5: zero-phase reactor 12, 13: input terminal of line noise filter, 21, 22, 23: input side power supply line Between capacitors, 31: common mode choke coil, 42, 43: capacitors between output side power supply lines, 5
1, 52, 53: capacitors between power supply line and ground,
62, 63: output terminal of line noise filter, 7
1: Ground terminal of line noise filter

Claims (5)

[Claims] 1. The average particle size measured at the largest dimension is 50 n
A line noise filter using a magnetic core composed of an Fe-based soft magnetic alloy having crystal grains equal to or less than m, wherein the crystal grains occupy at least 50% of the structure.
A line noise filter comprising a capacitor connected between each line on the input side of the noise filter. 2. The line noise filter according to claim 1, wherein a capacitor is connected between each line on the output side of the line noise filter. 3. The Fe-based soft magnetic alloy contains Si and / or B and Cu, Nb, Ta, W, Mo, Zr, Hf,
3. The line noise filter according to claim 1, further comprising at least one crystal grain refinement element selected from the group consisting of V and Ti. 4. A power converter comprising the line noise filter according to claim 1 on a power supply line side. 5. The power conversion device according to claim 4, wherein a zero-phase reactor is provided on a load side of the power conversion device.