JP4742306B2 - Noise reduction filter - Google Patents

Description

  The present invention relates to a noise reduction filter that reduces noise generated from a power converter that converts supplied power into AC power and supplies the load to a load.

  Patent Document 1 discloses a noise reduction device for a power conversion device that is installed between a commercial power source and a power conversion device and can simultaneously reduce normal mode and common mode conductive noise.

The configuration of this noise reduction device will be briefly described below.
Insert a capacitive element (or stray capacitance) between the power supply line connected to the commercial power supply and the ground line, and pass the voltage detected by this capacitive element through a high-pass filter to remove the high-frequency voltage component. Extract.
The extracted high frequency voltage component passes through a subtractor, arithmetic controller, and current generator, and a control current Icom for making the original high frequency voltage component zero is generated. Since this control current Icom is only a high-frequency component, most of it flows into the capacitance element (or stray capacitance).
In this way, the high-frequency voltage generated in the capacitance element (or stray capacitance) can be suppressed, and the conductive noise transmitted to the commercial power supply can be reduced. Note that normal mode noise and common mode noise are superimposed on the high-frequency voltage component detected by the electrostatic capacitance element (or stray capacitance) and the high-pass filter, and therefore, normal mode and common mode conductive noise are included in the control current Icom. The current component for suppressing is included.

JP 2003-88099 A

If the amount of conductive noise reduction by the conventional noise reduction device is insufficient, it is conceivable to use a passive filter consisting of passive elements. However, simply connecting the noise reduction device to the passive filter reduces the conductive noise. There is a problem in that the effect of doing this may not be achieved.
For example, consider a case where a capacitor is inserted between a power supply line and a ground line as a passive filter used in combination with a noise reduction device. This capacitor is commonly called a Y capacitor, and has a great effect on suppression of common mode noise. In this configuration, the capacitance element (or stray capacitance) of the noise reduction device and the Y capacitor are connected in parallel, and the control current Icom output from the noise reduction device is the capacitance element (or stray capacitance) and Y. The current is divided according to the impedance ratio of the capacitor. Since the noise reduction device obtains a noise reduction effect by flowing the control current Icom into the capacitance element (or stray capacitance), a part of the control current Icom is shunted to the Y capacitor. It will cause a decline.

The present invention has been made to solve the above-described problems, and an object of the present invention is to obtain a noise reduction filter that realizes an improvement in noise reduction performance.

The noise reduction filter according to the present invention includes a first capacitance element inserted between a plurality of power supply lines and a ground line, and converts the supplied power into AC power having an arbitrary frequency component and supplies it to a load. Is connected to the power converter , detects a high frequency noise voltage between the power supply line and the ground line, generates a control current for making the detected high frequency noise voltage zero, the control current is by outputting to the power supply line, and the noise reducing apparatus for reducing noise of the power converter provided between said first capacitive element and the noise reducing apparatus, the frequency components of the control current On the other hand, a first impedance element having a high impedance is provided.

The noise reduction filter according to the present invention includes a first capacitance element inserted between a plurality of power supply lines and a ground line, and converts the supplied power into AC power having an arbitrary frequency component and supplies it to a load. Is connected to the power converter , detects a high frequency noise voltage between the power supply line and the ground line, generates a control current for making the detected high frequency noise voltage zero, the control current is by outputting to the power supply line, and the noise reducing apparatus for reducing noise of the power converter provided between said first capacitive element and the noise reducing apparatus, the frequency components of the control current a first impedance element comprising a high impedance against, because with a, both of the noise reduction effect as the noise reduction effect of the noise reduction apparatus according to the first capacitive element to take full advantage That.

Embodiment 1 FIG.
1 is a diagram showing a circuit configuration using a noise reduction filter according to Embodiment 1 of the present invention.
In the figure, 3 is a capacitor as a first capacitance element inserted between the power supply line connected to the AC power source 1 and the ground line connected to the ground point 2, and 10 is disclosed in Patent Document 1. The conventional noise reduction device 4 described above, 4 is a first impedance element inserted between the capacitor 3 and the noise reduction device 10, 11 is a power conversion device, and 12 is connected to the subsequent stage of the power conversion device 11. Load. Since the capacitor 3 is inserted in the same manner for all three phases, only one phase is shown in the figure.

The noise reduction device 10 has the same configuration as that described in Patent Document 1, but only the portions necessary for explaining the present invention are extracted and shown.
5 is a capacitor inserted between the power supply line and the ground line, 6 is a voltage detection circuit for detecting the voltage V5 across the capacitor 5, 7 is connected to the output side of the voltage detection circuit 6, and is an active element such as an operational amplifier , 8 is a capacitor inserted between the power supply line and the output line of the active noise filter 7, and 9 is a resistor inserted between the capacitor 8 and the ground line. Since the noise reduction device 10 has the same configuration for all three phases, only one phase is shown in the figure.
The active noise filter 7 includes a high-pass filter, a subtracter, an arithmetic controller, and a current generator.

Next, the operation of the circuit according to the first embodiment of the present invention will be described.
The power converter 11 converts AC power from the AC power source 1 into DC power, converts this DC power into AC power having an arbitrary frequency, and drives the load 12. In the process of converting DC power to AC power of an arbitrary frequency, conductive noise is generated by the switching operation of a high-frequency switching element such as an IGBT, and this conductive noise is a power supply line and a ground line connected to the power converter 11. It is transmitted to the AC power source 1 via.

Therefore, in order to reduce the conductive noise to the AC power source 1, the noise reduction device 10 is used. The outline of the operation of the noise reduction apparatus 10 is as follows.
The voltage of the capacitor 5 is detected by the voltage detector 6, the high frequency voltage component is extracted by the high-pass filter in the active noise filter, and the high frequency voltage component is zeroed by the subtractor, arithmetic controller, and current generator in the active noise filter. A control current Icom is generated. Since this control current Icom is only a high-frequency component, most of it flows to the power supply line via the capacitor 6 and, as a result, flows into the capacitor 5. In this way, the noise reduction device 10 operates so that the high-frequency voltage generated in the capacitor 5 becomes zero, and the conductive noise to the AC power supply 1 is reduced.

  In addition, according to the structure of the noise reduction apparatus 10, the control current Icom for reducing the conductive noise of both modes is produced | generated by detecting the high frequency voltage with which the normal mode and the common mode conductive noise were superimposed. Since the control current Icom is directly injected into the path through which the conductive noise in both modes is transmitted, the control current Icom can be reduced simultaneously without distinguishing between the normal mode and the common mode.

  As described above, normal mode and common mode conductive noise can be reduced only by the noise reduction device 10, but the conductive noise can be further reduced by combining the noise reduction device 10 with a passive noise filter composed of passive elements. .

In Embodiment 1 of the present invention, a capacitor 3 is inserted between the power supply line and the ground line as one of the passive noise filters.
Since the capacitor 3 is connected in parallel with the AC power source 1 and has a low impedance with respect to a high frequency component, conductive noise to the AC power source 1 can be reduced.

If the capacitance value of the capacitor 3 is increased, the impedance to the high frequency component can be further reduced, so that the conductive noise to the AC power source 1 can be further reduced. On the other hand, the capacitance value of the capacitor 3 is increased. Leads to an increase in leakage current, and accordingly, the capacitance value of the capacitor 3 is appropriately determined according to the application environment of the noise filter, the user request, and the like.
When the capacitor 3 and the noise reduction device 10 are combined, conductive noise may increase simply by connecting them. Therefore, to achieve both the noise reduction effect by the capacitor 3 and the noise reduction effect by the noise reduction device 10, Use connection form.

Since the noise reduction device 10 reduces the conductive noise by flowing a control current Icom that makes the high-frequency voltage detected by the capacitor 5 zero, the noise reduction device 10 and the capacitor 3 are connected to each other. If so, the control current Icom flows into the capacitor 3 and the noise reduction device 10 cannot reduce the conductive noise. Therefore, an impedance element 4 is provided between the noise reduction device 10 and the capacitor 3 so as to have a high impedance with respect to the frequency component of the control current Icom.
With such a configuration, most of the control current Icom can flow through the capacitor 5, so that both the noise reduction effect by the noise reduction device 10 and the noise reduction effect by the capacitor 3 can be achieved. Moreover, since the impedance element 4 becomes high impedance also with respect to the conductive noise from the power converter device 11 to the alternating current power supply 1, it is possible to reduce the conductive noise and to conduct more than the case of the noise reducing device 10 alone. Noise can be reduced.

Embodiment 2. FIG.
2 is a diagram showing a circuit configuration using a noise reduction filter according to Embodiment 2 of the present invention. In the figure, 1, 2, 3, 5-9, 10, 11, and 12 are the same as those in FIG.
As described in the first embodiment, by providing the impedance element 4, it is possible to achieve both the noise reduction effect by the noise reduction device 10 and the noise reduction effect by the capacitor 3, and further the noise reduction effect of the impedance element 4 itself can be expected. In the second embodiment, an example in which the common mode reactor 13 and the normal mode reactors 14, 15, 16 are connected in series as the impedance element 4 is shown.

  Since the inductance value can be given in common by inserting the common mode reactor 13, the impedance to the common mode component of the control current Icom output from the noise reduction device 10 can be increased, and the common mode of the control current Icom can be increased. The component can be prevented from flowing into the capacitor 3. Further, by inserting normal mode reactors 14, 15, and 16, the inductance value can be given normally, so that the impedance to the normal mode component of the control current Icom output from the noise reduction device 10 can be increased, and control is performed. It is possible to suppress the normal mode component of the current Icom from flowing into the capacitor 3.

  Moreover, since the common mode reactor 13 and the normal mode reactors 14, 15, 16 have high impedance with respect to the conductive noise from the power converter 11 to the AC power supply 1, the conductive noise can be reduced, and the noise reducing device 10. Thus, the conductive noise can be further reduced by combining the noise reduction effect by the capacitor 3 and the noise reduction effect by the capacitor 3.

Specifically, the common mode reactor and the normal mode reactor may have a shape in which the power supply line is wound around the magnetic core, or a shape in which the power supply line is penetrated through the magnetic core. The magnetic core may be a toroidal shape or a shape in which two U-shapes are bonded to face each other, and an easy core shape may be selected for manufacturing the reactor.
In addition, when the current value flowing through the power supply line is several hundred amperes, the cross-sectional area of the power supply line is several tens of mm ² or more, and the size of the reactor increases when wound around a normal wire. Therefore, the normal mode reactor is downsized. If desired, a bus bar made of a flat copper wire or an arbitrary cross-sectional area may be used as the winding. In this case, it is desirable to insulate the winding surface of the flat copper wire or bus bar.

  When normal mode reactors 14, 15, and 16 are arranged close to each other, it is necessary to insulate the windings because there is a possibility of a short circuit between wires or a ground fault unless an appropriate insulation distance is observed. . However, if insulation treatment cannot be performed due to manufacturing problems, the space distance and creepage distance between the normal mode reactors 14, 15, and 16 and the space distance and creepage distance between the normal mode reactors 14, 15, 16 and the ground are An insulation distance determined by the voltage value and frequency of the AC power supply 1 is satisfied, or an insulation sheet having a sufficient withstand voltage is inserted between the normal mode reactors.

  Although it has been described above that the normal mode reactors 14, 15, and 16 may be manufactured using a magnetic core, the use of the core causes the problem of heat generation due to magnetic flux saturation and an increase in the size of the reactor due to an increase in power supply line current. Therefore, there is a method of forming a reactor without using a magnetic core. In this case, an air core reactor is used. For the magnetic flux leaking from the air core reactor, a magnetic flux shielding plate or a magnetic flux shielding sheet may be used.

Embodiment 3 FIG.
FIG. 3 is a diagram showing a circuit configuration using a noise reduction filter according to Embodiment 3 of the present invention. In the figure, 1, 2, 3, 5-9, 10, 11, 12, 13, 14-16 are the same as in FIG.
In the second embodiment, the common mode reactor 13 and the normal mode reactors 14, 15, and 16 are used as the impedance element 4 in the second embodiment. However, in the third embodiment, the capacitors 17 and 17 are further provided between the power supply lines. The example which inserted 18 and 19 was shown.

By inserting the capacitors 17, 18, 19, a bypass circuit for a high frequency component is formed between the power supply lines, and the normal mode component of the control current Icom can be prevented from flowing into the capacitor 3. . Although not shown, when the capacitance values of the capacitors 17, 18, and 19 are increased, a discharge resistor is normally connected in parallel with each capacitor.
Further, since the capacitors 17, 18 and 19 have low impedance with respect to the conductive noise from the power converter 11 to the AC power supply 1, they have a conductive noise reduction effect, and the noise reduction effect by the noise reduction device 10 The conductive noise can be further reduced by combining the noise reduction effect by the capacitor 3 and the noise reduction effect by the common mode reactor 13 and the normal mode reactors 14, 15, 16.

Embodiment 4 FIG.
4 is a diagram showing a circuit configuration using a noise reduction filter according to Embodiment 4 of the present invention. In the figure, 1, 2, 3, 5-9, 10, 11, 12, 13, 14-16, and 17-19 are the same as those in FIG.
In the third embodiment, an example in which the common mode reactor 13, the normal mode reactors 14, 15, 16 and the capacitors 17, 18, 19 are used as the impedance element 4 is described. However, in the fourth embodiment, the capacitor 3, The example which provided the earth reactor 20 in the ground line between the noise reduction apparatuses 10 was shown.

The earth reactor 20 can prevent the control current Icom from flowing into the capacitor 3 via the ground line.
In addition, since the earth reactor 20 has a high impedance with respect to conductive noise flowing from the power conversion device 11 to the AC power supply 1 via the ground line, the ground reactor 20 has an effect of reducing conductive noise. The conductive noise is further reduced by combining the reduction effect, the noise reduction effect by the capacitor 3, the noise reduction effect by the common mode reactor 13 and the normal mode reactors 14, 15, and 16, and the noise reduction effect by the capacitors 17, 18, and 19. Can be reduced.

Embodiment 5 FIG.
5 is a diagram showing a circuit configuration using a noise reduction filter according to Embodiment 5 of the present invention. In the figure, 1, 2, 3, 5-9, 10, 11, 12, 13, 14-16, 17-19, and 20 are the same as those in FIG. The power converter 11 may have a built-in simple filter 21 as a standard. Although the configuration of the simple filter 21 is not shown, it is generally composed of passive elements such as capacitors and reactors.
The conductive noise can be further reduced by combining the noise reduction effect by the simple filter 21 and the noise reduction effect by the passive filter shown in the first to fourth embodiments.
Note that since a leakage current occurs when a capacitor is inserted between the power supply line and the ground line as an element constituting the simple filter 21, the simple filter is used when determining the capacitance value of the capacitor 3. The leakage current value of the entire noise reduction filter including the leakage current value of 21 is designed to be a value according to the application environment of the noise filter, the user request, and the like.

Embodiment 6 FIG.
6 is a diagram showing a circuit configuration using a noise reduction filter according to Embodiment 6 of the present invention. In the figure, 1, 2, 3, 5-9, 10, 11, 12, 13, 14-16, 17-19, and 20 are the same as those in FIG.

Reference numeral 22 denotes a second impedance element inserted between the capacitor 3 and the AC power supply 1, and reference numeral 23 denotes a third impedance element inserted between the noise reduction device 10 and the power conversion device 11.
The passive filter shown in the first to fifth embodiments can prevent the control current Icom from flowing into the capacitor 3, and can achieve both the noise reduction device 10 and the noise reduction effect of the passive filter. However, there are cases where it is difficult to cope with the noise reduction effect of the noise reduction device 10 and the passive filter when complying with the EMI standard having a small allowable conduction noise value. In this case, the noise reduction effect by the noise reduction apparatus 10 and the passive filter can be improved by providing the impedance element 22.
Moreover, by providing the impedance element 23 between the noise reduction device 10 and the power conversion device 11, it is possible to suppress the control current Icom from flowing into the power conversion device 11. Moreover, since the impedance element 23 becomes a high impedance with respect to the conductive noise from the power converter 11 to the AC power supply 1, the conductivity transmitted from the power converter 11 to the AC power supply 1 via the power supply line and the ground line. Since it has the effect of reducing noise, the conductive noise can be further reduced by combining the noise reduction effect by the passive filter and the noise reduction device 10 shown in the first to fifth embodiments.

Embodiment 7 FIG.
FIG. 7 is a diagram showing a circuit configuration using a noise reduction filter according to Embodiment 7 of the present invention. In the figure, 1, 2, 3, 5-9, 10, 11, 12, 13, 14-16, 17-19, and 20 are the same as those in FIG.
In the seventh embodiment, the common mode reactor 24 is used as the impedance element 22, and the capacitors 26, 27, and 28 inserted between the power supply lines and the common mode reactor 29 are used as the impedance element 23. .

Since the common inductance value can be given by inserting the common mode reactor 24, the noise reduction device 10 and the passive filter shown in the first to fifth embodiments can further reduce the common mode noise reduction effect. Can be improved.
By inserting the capacitors 26, 27 and 28, a bypass circuit for the high frequency component is formed between the power supply lines, and the normal mode component of the control current Icom is prevented from flowing into the power conversion device 11. Can do.
Although not shown, when the capacitance values of the capacitors 26, 27, and 28 are large, a discharge resistor is usually connected in parallel with each capacitor.

By inserting the common mode reactor 29, the common inductance value can be provided, so that the impedance to the common mode component of the control current Icom output from the noise reduction device 10 can be increased, and the common of the control current Icom can be increased. It is possible to suppress the mode component from flowing into the power converter 11.
Capacitors 26, 27, and 28 have low impedance with respect to conductive noise from power converter 11 to AC power supply 1, and common mode reactor 29 has resistance to conductive noise from power converter 11 to AC power supply 1. Since it becomes high impedance, it has the effect of reducing conductive noise, and the conductive noise is further reduced by combining the noise reduction effect by the passive filter and the noise reduction device 10 shown in the first to fifth embodiments. It can be reduced.

Embodiment 8 FIG.
FIG. 8 is a diagram showing a circuit configuration using a noise reduction filter according to Embodiment 8 of the present invention. In the figure, 1, 2, 3, 5-9, 10, 11, 12, 13, 14-16, 17-19, 20, 24, 26-28, 29 are the same as in FIG. Omitted.
In the seventh embodiment, as the impedance element 23, an example using the capacitors 26, 27, and 28 inserted between the power supply lines and the common mode reactor 29 is shown. However, in the eighth embodiment, the impedance element 23 is used. As an example, the normal mode reactors 30, 31, 32, and the capacitor 33 inserted between the power supply line and the ground line are shown.

  By inserting the normal mode reactors 30, 31, 32, the inductance value can be given normally, so that the impedance to the normal mode component of the control current Icom output from the noise reduction device 10 can be increased, and the control is performed. It is possible to suppress the normal mode component of the current Icom from flowing into the power converter 11.

  By inserting the capacitor 33, a bypass circuit is formed between the power supply line and the ground line for high frequency components. That is, since conductive noise from the power converter 11 flows to the capacitor 33, the conductive noise transmitted to the AC power source 1 via the common mode reactor 29, the capacitors 26, 27, and 28 and the noise reducing device 10 can be reduced. it can. However, since the increase in the capacitance value of the capacitor 33 leads to an increase in the leakage current value, the capacitance value of the capacitor 33 together with the capacitance value of the capacitor 3 according to the application environment of the noise filter, the user request, and the like. Determine appropriately.

  Capacitors 26, 27, and 28 and capacitor 3 have low impedance with respect to conductive noise from power converter 11 to AC power supply 1, and common mode reactor 29 and normal mode reactors 30, 31, and 32 convert power. Since it becomes high impedance with respect to the conductive noise from the apparatus 11 to the AC power supply 1, it has the effect of reducing the conductive noise, and the passive filter and the noise reducing apparatus 10 shown in the first to fifth embodiments In combination with the noise reduction effect, the conductive noise can be further reduced.

Embodiment 9 FIG.
9 is a diagram showing a circuit configuration using a noise reduction filter according to Embodiment 9 of the present invention. In the figure, 1, 2, 3, 5-7, 11, 12, 13, 14-16, 17-19, 20, 24, 26-28, 29, 30-32, 33 are the same as in FIG. The description is omitted.

  The noise reduction device 10a in the ninth embodiment has a configuration in which the capacitor 8 and the resistor 9 are omitted from the noise reduction device 10 shown in the first to eighth embodiments, and the control current Icom from the active noise filter 7 is obtained. The capacitor 8 and the resistor 9 are not used, but are directly injected into the power supply line.

Embodiment 10 FIG.
The circuit of the noise reduction device 10 is composed of a plurality of operational amplifiers, resistors, capacitors, and transistors.
In the configurations shown in the first to ninth embodiments, since the passive filter composed of passive elements is used in combination with the noise reducing device 10, the noise reducing device 10 is used when these passive filters exist. The circuit constants are determined so that the circuit of FIG.

Embodiment 11 FIG.
In the configurations shown in the first to ninth embodiments, the noise reduction device 10 is used with a passive filter made of a passive element such as a capacitor or a reactor. However, the passive filter has equivalent performance instead of these passive filters. A filter composed of active elements may be used in combination.

Embodiment 12 FIG.
In the first to ninth embodiments and the eleventh embodiment, the case where the power supply line is connected to the AC power supply 1 has been described. However, a DC power supply may be used.

Embodiment 13 FIG.
10 is a diagram showing a circuit configuration using a noise reduction filter according to Embodiment 13 of the present invention, and FIG. 11 is a diagram showing a noise reduction processing method according to Embodiment 13 of the present invention. In the figure, 1, 2, 3, 11, and 12 are the same as those in FIG.

As a connecting line between the power converter 11 and the load 12, a shielded cable in which a power line and a ground line are shielded is used. Further, the capacitor 3 and the common mode reactor 24 are housed in a casing 34 made of a conductive material, and the casing 34 is connected to the ground point 2 to have the same potential. Further, as the surface treatment of the housing 34, the entire surface may be unpainted, or a part of the unpainted surface 37 may be left as shown in FIG. 11 and the other surface may be painted. This non-painted surface 37 has the same potential as the ground point 2.
As shown in FIG. 11, the shielded cable is removed by removing a part of the outer skin 38 to expose the shield part 35, and the shield part 35 is brought into contact with the non-painted surface 37 and fixed with a fixture 36. The shield part 35 is connected to the ground line of the shield cable at the output part of the power converter 11 or the input part of the load 12.

With this configuration, the floating noise is prevented from being generated by the conductive noise flowing in the AC power supply 1 through the floating capacitance existing between the shield portion 35 of the shield cable and the wall surface or floor surface on which the shield cable is laid. An impedance path lower than the capacitance impedance is formed between the shield portion 35 and the housing 34. Therefore, conductive noise flows through the low impedance path and flows into the capacitor 3. Note that the conductive noise flowing as described above hardly flows into the AC power supply 1 through the surface of the housing 34. This is because the conductive noise flowing in the path is mainly common mode noise of several MHz or higher, and the impedance of the capacitor 3 is low impedance for high frequencies of several MHz or higher, so most of the conductive noise is AC power supply. This is because it flows into the capacitor 3 instead of 1. Further, if the common mode reactor 24 is inserted between the AC power supply 1 and the capacitor 3, the common mode noise that has passed through the capacitor 3 does not flow into the AC power supply 1.
By using the above configuration, it is possible to reduce the conductive noise flowing into the AC power supply 1 through the wall surface or the floor surface, and further improve the noise reduction effect. Moreover, it also has an effect of reducing radioactive noise by being housed in a housing 34 made of a conductive material.

FIG. 12 shows a noise reduction processing method according to Embodiment 13 of the present invention.
In the above description, the common mode reactor 24 and the capacitor 3 are housed in the casing 34. However, as shown in FIG. 12, the common mode reactor 24, the capacitor 3, the first impedance element 4, and the noise reduction device. 10 may be housed in the housing 34. In this case, since the noise reduction effect of the first impedance element 4 and the noise reduction device 10 is added, the noise reduction effect can be further improved.

FIG. 13 shows a noise reduction processing method according to Embodiment 13 of the present invention.
12 shows a form in which the common mode reactor 24, the capacitor 3, the first impedance element 4, and the noise reduction device 10 are housed in the casing 34. However, as shown in FIG. 13, the common mode reactor 24, the capacitor 3, the first impedance element 4, the noise reduction device 10, and the third impedance element 23 may be housed in the casing 34. In this case, since the noise reduction effect of the third impedance element 23 is added, the noise reduction effect can be further improved.

The noise reduction filter of the present invention can further improve the noise reduction effect of the noise reduction device, and corresponds to the system construction of the power conversion device considering the reduction of conductive noise and the EMI standard with a small allowable value of conductive noise. The system construction of the power conversion device is facilitated.

It is a figure which shows the circuit structure using the noise reduction filter which concerns on Embodiment 1 of this invention. It is a figure which shows the circuit structure using the noise reduction filter which concerns on Embodiment 2 of this invention. It is a figure which shows the circuit structure using the noise reduction filter which concerns on Embodiment 3 of this invention. It is a figure which shows the circuit structure using the noise reduction filter which concerns on Embodiment 4 of this invention. It is a figure which shows the circuit structure using the noise reduction filter which concerns on Embodiment 5 of this invention. It is a figure which shows the circuit structure using the noise reduction filter which concerns on Embodiment 6 of this invention. It is a figure which shows the circuit structure using the noise reduction filter which concerns on Embodiment 7 of this invention. It is a figure which shows the circuit structure using the noise reduction filter which concerns on Embodiment 8 of this invention. It is a figure which shows the circuit structure using the noise reduction filter which concerns on Embodiment 9 of this invention. It is a figure which shows the circuit structure using the noise reduction filter which concerns on Embodiment 13 of this invention. It is a figure which shows the noise reduction processing method which concerns on Embodiment 13 of this invention. It is a figure which shows the noise reduction processing method which concerns on Embodiment 13 of this invention. It is a figure which shows the noise reduction processing method which concerns on Embodiment 13 of this invention.

Explanation of symbols

  1 AC power supply, 2 ground point, 3 first capacitor, 4 first impedance element, 5 second capacitor, 6 voltage detection circuit, 7 active noise filter, 8 capacitor, 9 resistance, 10, 10a noise reduction device, DESCRIPTION OF SYMBOLS 11 Power converter device, 12 Load, 13 Common mode reactor, 14-16 Normal mode reactor, 17-19 Capacitor, 20 Earth reactor, 21 Simple filter, 22 2nd impedance element, 23 3rd impedance element Impedance element, 24 Common mode reactor, 26-28 capacitor, 29 Common mode reactor, 30-32 Normal mode reactor, 33 capacitor, 34 Housing, 35 Shield part of shielded cable, 36 sheets Fastener head portion, the conductive portion of the 37 surface of the housing, the outer skin 38 shielded cable, V5 voltage across the capacitor 5, Icom control current.

Claims (18)

A first capacitance element inserted between a plurality of power supply lines and a ground line;
A high-frequency noise voltage between the power supply line and the ground line is detected by detecting a high-frequency noise voltage connected to a power conversion device that converts supply power into AC power having an arbitrary frequency component and supplies the load to a load. Generating a control current for zeroing and outputting the control current to the power supply line, thereby reducing the noise of the power converter ,
A noise reduction filter comprising: a first impedance element that is provided between the noise reduction device and the first capacitance element and has a high impedance with respect to a frequency component of the control current .
2. The noise reduction filter according to claim 1, wherein the first impedance element is constituted by a normal mode reactor. The noise reduction filter according to claim 2, wherein a common mode reactor is provided as the first impedance element. The noise reduction filter according to claim 2 or 3, wherein a capacitor is provided between the power supply lines as the first impedance element. The noise reduction filter according to any one of claims 2 to 4, wherein an earth reactor is provided on the ground line as the first impedance element. The noise reduction filter according to any one of claims 2 to 5, wherein a simple filter built in the power converter is operated. The noise reduction filter according to claim 1, wherein a second impedance element is provided between the first capacitance element and the plurality of power supply lines. The noise reduction filter according to any one of claims 1 to 7, wherein a third impedance element is provided between the noise reduction device and the power conversion device. The noise reduction filter according to claim 7 or 8, wherein the second impedance element is configured by a common mode reactor. The noise reduction filter according to claim 8, wherein the third impedance element is configured by a common mode reactor. The noise reduction filter according to claim 10, wherein a normal mode reactor is provided as the third impedance element. The noise reduction filter according to claim 10 or 11, wherein a capacitor is provided between the power supply lines as the third impedance element. 13. The noise reduction filter according to claim 10, wherein a capacitor is provided between the power supply line and the ground line as the third impedance element. 14. The noise according to claim 10, wherein the first impedance element, the second impedance element, and the third impedance element are configured by active elements having equivalent performance. Reduction filter. The noise reduction filter according to claim 1, wherein the first capacitance element is configured by an active element having equivalent performance. While using a shielded cable that is shielded common to the power line and the ground line as a connection line between the power converter and the load,
A first capacitance element inserted between a plurality of power supply lines and a ground line; and a second impedance element provided between the first capacitance element and the plurality of power supply lines. noise reduction, characterized in that when the accommodated in a casing made of electrically conductive material, and the housing, the ground line of the first capacitance element to the same potential and the ground line of the shielded cable filter.
A noise reduction device that reduces noise of a power conversion device that converts supply power into alternating current power having an arbitrary frequency component and supplies the load to the housing, and the noise reduction device and the first capacitance element. The noise reduction filter according to claim 16, wherein the first impedance element provided between the first impedance element and the first impedance element is accommodated. 18. The noise reduction filter according to claim 17, wherein a third impedance element provided between the noise reduction device and the power conversion device is accommodated in the housing.

Images