JP2006020389A5 - - Google Patents

Description

Noise filter and motor drive device including the same

  The present invention relates to a noise filter that reduces high-frequency noise generated in a switching operation of a motor drive device such as a matrix converter (PWM cycloconverter) and an inverter, and a motor drive device including the noise filter.

FIG. 8 is an explanatory diagram showing the flow of a common mode current of a general motor drive device targeted by the prior art and the present invention.
In FIG. 8, 100 is an AC power source, 101 is a motor, 107 is a motor driving device driving the motor 101, I1 is a common mode current flowing into the motor 101, I2 is a common mode current flowing out to the AC power source 100 side, I3 Is a common mode current flowing in the ground line of the motor 101, and GND is ground.
FIG. 9 is a common mode equivalent circuit diagram of a conventional motor driving apparatus (FIG. 8) targeted by the prior art and the present invention.
In FIG. 9, Vc is a common mode voltage, Cc is a stray capacitance between the motor winding and the motor frame, Rl1 and Rl2 are wiring resistances, and Ll1 and Ll2 are wiring inductances.
FIG. 10 is a waveform diagram showing the result of simulating the common mode current of each part in the conventional motor driving apparatus (FIG. 8) targeted by the prior art and the present invention, and the switching performed in the motor driving apparatus 107. FIG. 10 is a result of simulating the common mode current of each part at the moment when the common mode voltage generated by the above changes by a common mode equivalent circuit shown in FIG. 9. The horizontal axis represents time, and the vertical axis represents the current value.
In all the simulations described in this specification, the same numerical values are used for the respective constants (wiring inductance and resistance, stray capacitance, filter constant, etc.) in order to make the conditions equal.
As can be seen from FIG. 10, a common mode current of I1≈I2≈I3 flows through the ground line.

FIG. 11 is a spectrum diagram of common mode currents I1 and I2 in a simulation (FIG. 10) of a general motor driving apparatus targeted by the prior art and the present invention. The horizontal axis indicates the frequency, and the vertical axis indicates the current value of the frequency component in logarithm.
As shown in FIG. 11, the frequency components of the common mode current I1 flowing into the motor 101 and the common mode current I2 flowing out to the AC power supply 100 side are approximately several MHz, although depending on the wiring length. This is because the common mode current passes through the stray capacitance of each part such as between the stator winding and the frame of the motor 101 or between the power line and the ground line, but the stray capacitance and wiring inductance of the common mode path are small. It becomes. The common mode current including the high-frequency component causes conduction noise and radiation noise that cause problems for other devices.
Conventionally, an input side noise filter and an output side noise filter have been considered as means for reducing the common mode current (see, for example, Patent Documents 1 and 2).

FIG. 12 is an explanatory diagram showing a motor drive device using a conventional input side noise filter.
In FIG. 12, reference numeral 103 denotes an input side noise filter. The same reference numerals as those in FIG. 6 denote the same components as those in FIG.
Moreover, FIG. 13 is an internal block diagram which shows the input side noise filter of a prior art.
In FIG. 13, Li is a common mode choke coil of the input side noise filter, Cx is a normal mode noise reducing bypass capacitor Y-connected from the R phase, S phase, and T phase, respectively, and Cy is a neutral point of Cx and a ground line A grounding capacitor connected between them.
Hereinafter, the function of the input side noise filter of the prior art will be described with reference to FIGS.
Here, the frame of the motor 101 is grounded to the neutral point of the AC power supply 100 or one of the three phases. The input side noise filter 103 is inserted between the input side of the motor driving device 107 and the AC power supply 100. As a result, the common mode choke coil Li increases the impedance on the AC power supply 100 side in the common mode path, and bypass capacitors Cx and Cy having a smaller impedance than the common mode path are added to the input side of the motor driving device 107. Therefore, it is possible to reduce the common mode current I2 flowing out to the AC power supply 100 side.

FIG. 14 is a common mode equivalent circuit diagram in the prior art (FIG. 12).
14, the same reference numerals as those in FIGS. 8 and 9 denote the same components as those in FIGS.
FIG. 15 is a waveform diagram of the result of simulating each part common mode current in the prior art (FIG. 12), and each part common mode current when the input side noise filter 103 of the prior art is added to the motor driving device 107. This is a result of simulation with the common mode equivalent circuit shown in FIG.
FIG. 16 is a spectrum diagram of common mode currents I1 and I2 in the simulation of the prior art (FIG. 15).
15 and 16 are compared with FIGS. 10 and 11 described above, by adding the noise filter 103 to the input portion of the motor driving device 107, the common mode current I2 flowing out to the AC power supply 100 side is reduced. I understand.

FIG. 17 is an explanatory diagram showing a motor drive device using a conventional output side noise filter.
In FIG. 17, reference numeral 102 denotes an output side noise filter, and If denotes a bypass current. The same reference numerals as those in FIG. 12 indicate the same components and contents as those in FIG.
FIG. 18 is an internal configuration diagram of a conventional output-side noise filter.
In FIG. 18, Lo is a common mode choke coil of the output side noise filter, Cfu, Cfv, Cfw are bypass capacitors connected to the U phase, V phase, and W phase, and Rbu, Rbv, Rbw are bypass capacitors Cfu, Cfv, A damping resistor connected to Cfw and the common line. The common line is grounded together with the motor frame via a ground terminal E.
Hereinafter, the function of the conventional output side noise filter 102 will be described with reference to FIGS.
The neutral point of the AC power supply 100 or one of the three phases and the frame of the motor 101 are grounded. The principle of reducing the common mode current I1 is as follows. That is, the common mode voltage is divided by the common mode choke coil Lo, and the capacitors Cfu, Cfv, Cfw having a small impedance in parallel with the stray capacitance between the stator winding and the frame of the motor 101 and the damping resistors Rbu, Rbv, A bypass circuit constituted by Rbw is added to reduce the common mode current I1 flowing into the motor 101.

FIG. 19 is a common mode equivalent circuit diagram in the prior art (FIG. 17). 19, the same reference numerals as those in FIGS. 14 and 17 denote the same components as those in FIGS.
20 is a waveform diagram as a result of simulating each part common mode current in the prior art (FIG. 17), and shows each part common mode current when the conventional output side noise filter 102 is added to the motor driving device 107. FIG. It is the result of simulating with the common mode equivalent circuit shown in FIG.
FIG. 21 is a spectrum diagram of the common mode currents I1 and I2 in the conventional simulation (FIG. 20).
20 and 21 are compared with FIGS. 10 and 11, it can be seen that the common mode current I1 flowing into the motor 101 can be reduced by adding the noise filter 102 to the output section of the motor driving device 107. FIG. By reducing the common mode current I1, it is possible to suppress motor failure due to electric corrosion caused by dielectric breakdown of the motor windings or increased bearing current.

FIG. 22 is an explanatory diagram showing a motor drive device using a combination of a conventional input side noise filter and an output side noise filter.
In FIG. 22, reference numeral 110 denotes a noise filter that combines a conventional input side noise filter 103 and an output side noise filter 102. The same reference numerals as those in FIGS. 12 and 17 denote the same components as those in FIGS.
FIG. 23 is a common mode equivalent circuit diagram in the prior art (FIG. 22), and the same reference numerals as those in FIGS. 12 and 19 denote the same components as those in FIGS.
FIG. 24 is a waveform diagram as a result of simulating each part common mode current in the prior art (FIG. 22), and a noise filter 110 in which the conventional input side noise filter 103 and the output side noise filter 102 are combined with the motor driving device 107. It is the result of having simulated each part common mode electric current at the time of adding with the common mode equivalent circuit shown in FIG.
FIG. 25 is a spectrum diagram of common mode currents I1 and I2 in the simulation of the prior art (FIG. 24).
Comparing the simulation results of FIGS. 24 and 25 with FIGS. 10 and 11, by combining the input side noise filter and the output side noise filter of the prior art, the common mode current I2 flowing out to the AC power source 100 side and the motor 101 are compared. It can be seen that the common mode current I1 flowing in can be reduced.
Japanese Patent Laid-Open No. 10-107571 (page 3-5, FIG. 4) JP 2001-69762 A (page 6-10, FIG. 1-21)

  However, when a noise filter is added to the input side of the motor drive device, the common mode current I2 flowing out to the AC power supply side is reduced, as can be seen from the comparison between the simulation FIG. 10 and FIG. The common mode current I1 flowing in increases, so that there has been a problem that electric corrosion occurs due to dielectric breakdown of the motor windings and increase in bearing current, resulting in motor failure.

  In addition, when a noise filter is added to the output side of the motor drive device, instead of reducing the common mode current I1, the bypass current If flows, so that the high frequency noise flowing out to the AC power source side is increased as a result. There is a possibility that. In general, the conventional output side noise filter is often added as an external option for the motor drive device. When the motor drive device is vector controlled, the vector control current sensor must be rearranged. However, since it is generally impossible to rearrange the motor, the motor has to be driven by V / f control.

  Further, when the input side noise filter and the output side noise filter are added in combination, the effect of reducing the common mode current I2 flowing out to the AC power supply side is reduced as compared with the case where only the input side noise filter is added. was there. This is because the common mode current I1 can be reduced by adding the output side filter, but the bypass current If of the output side filter flows, and as a result, the high frequency noise flowing out to the AC power source side is increased. Because it ends up.

The present invention has been made in view of such problems, and an object of the present invention is to provide a noise filter that can reduce high-frequency noise to the AC power supply side and reduce common mode current flowing in the motor. To do.
Furthermore, it aims at providing the motor drive device carrying the noise filter which enables not only V / f control but vector control.

In order to solve the above problem, the invention according to claim 1 is a noise filter that includes an input-side noise filter connected to an AC power source and an output-side noise filter connected to a motor, and is used together with a motor driving device. side noise filter includes a Y-connected capacitors from the AC power supply phase, the Y is a neutral point of connection to a capacitor to have a connection to a ground capacitor between the ground portion, of the Y-connected capacitor It has a common line for electrically connecting the neutral point and the bypass circuit portion of the output side noise filter.

  The invention according to claim 2 is the noise filter according to claim 1, wherein the noise filter has a structure in which the input side noise filter and the output side noise filter are integrated. .

Further, an invention according to claim 3, wherein, in the noise filter according to claim 1, wherein the input noise filter, a common mode choke coil which is electrically connected to an AC power source phase in series, the phase of the common mode choke A normal mode noise reducing bypass capacitor Y-connected from the coil, and a grounding capacitor electrically connected between a neutral point of the normal mode noise reducing bypass capacitor and a grounding portion, and the output side noise filter, a common mode choke coil which is electrically connected to the output of each phase in series with the motor drive device is electrically connected at one end to said phase common mode choke coil, is the bypass circuit portion electrically connected to the other end A bypass capacitor and a series body composed of a damping resistor. To have.

Further, an invention according to claim 4, wherein, in the noise filter according to claim 1, wherein the input noise filter, and the neutral point of the Y-connected capacitors, and the bypass circuit portion of the output-side noise filter It is characterized by having a connection terminal for connection.
According to a fifth aspect of the present invention, in the noise filter according to any one of the first to fourth aspects, the input side noise filter is a filter that reduces a noise terminal voltage, and the output side noise filter is a common that flows into a motor. It is a filter that reduces the mode current.
According to a sixth aspect of the present invention, in the motor drive device in which the noise filter is mounted, the mounted noise filter is the noise filter according to the first to fifth aspects.
According to a seventh aspect of the present invention, there is provided a motor driving device including the noise filter according to the sixth aspect, wherein the motor driving device is a matrix converter.

According to the noise filter of the present invention, it is possible to reduce high-frequency noise to the power supply side and reduce the common mode current flowing through the motor, so that the motor winding insulation breakdown, motor failure due to electrolytic corrosion, and peripheral devices Has the effect of suppressing malfunctions. Further, since the capacitance of the motor drive device input side capacitor (Cy) can be made smaller than that of the noise filter according to the prior art, the fundamental leakage current can be reduced, leading to prevention of electric shock.
In addition, according to the motor drive device equipped with the noise filter of the present invention, the motor can be driven not only by V / f control but also by vector control, and as a result, the arrangement of the vector control current sensor is changed. Save time and effort.

  Hereinafter, specific examples of the present invention will be described with reference to the drawings.

FIG. 1 is an explanatory diagram showing a motor drive device to which an input side noise filter and an output side noise filter are added according to the present invention.
In FIG. 1, 100 is an AC power source having a neutral point or one of three phases grounded, 101 is a motor having a frame grounded, 102 is an output side noise filter, and 105 is an input side noise filter according to the present invention. , 106 are common wires, and 107 is a motor driving device.
FIG. 2 is an internal configuration diagram of the input side noise filter 105 of the present invention.
In FIG. 2, Li is a common mode choke coil of the input side noise filter, Cx is a normal mode noise reduction bypass capacitor Y-connected from the R phase, S phase, and T phase, respectively, and Cy is a neutral point B and ground of Cx A grounding capacitor connected between the lines A. Further, the input side noise filter 105 of the motor driving device of the present invention is a terminal block C that enables the bypass circuit portion E of the output side noise filter 102 of the motor driving device to be connected to the neutral point B of Cx. The structure is provided. The configuration of the output side noise filter 102 may be the same as that of the prior art shown in FIG. 18, and the internal configuration is not limited as long as the bypass circuit section E is provided.

The present invention (FIGS. 1 and 2) is different from the prior art shown in FIGS.
In other words, the motor drive device 107 of the present invention includes an input side noise filter 105 and an output side noise filter 102, and the input side noise filter 105 is used for reducing normal mode noise Y-connected from the R phase, the S phase, and the T phase. The bypass capacitor Cx, the ground capacitor Cy connected between the neutral point B of the bypass capacitor Cx and the ground line (A), and the neutral point B of the bypass capacitor Cx are provided on the output side noise filter of the motor drive device 107. The terminal block C is connected to the bypass circuit portion E 102 and the common line 106.
Hereinafter, the functions of the input side noise filter and the output side noise filter of the present invention will be described with reference to FIGS.
The noise filter 105 on the input side of the motor drive device 107 reduces the noise terminal voltage for preventing outflow of high frequency noise to the AC power supply 100 side, and the noise filter 102 on the output side of the motor drive device 107 is a common that flows into the motor 101. Reduce mode current.
By making the common line of the input side noise filter 105 and the output side noise filter 102 common, the common mode current flowing in the AC power supply 100 side and the motor 101 is bypassed to the common line 106 and circulated in the motor driving device 107. We do not let it flow out.

FIG. 3 is a common mode equivalent circuit diagram in the present invention (FIG. 1).
3, the same reference numerals as those in FIGS. 1, 2, and 23 denote the same components as those in FIGS.
FIG. 4 is a waveform diagram as a result of simulating each part common mode current in the present invention (FIG. 1), and each part when the input side noise filter 105 and the output side noise filter 102 of the present invention are added to the motor driving device 107. It is the result of having simulated the common mode electric current using the common mode equivalent circuit diagram shown in FIG.
FIG. 5 is a spectrum diagram of common mode currents I1 and I2 in the simulation of the present invention (FIG. 4).
Comparing the simulation results of FIGS. 24 and 25 of the prior art and FIGS. 4 and 5 of the present invention, the present invention reduces the common mode current I2 flowing into the AC power supply 100 side and the common mode current I1 flowing into the motor 101. It can be seen that the vibration of the common mode current I3 can also be reduced.

FIG. 6 is an explanatory diagram showing the configuration of the second embodiment of the present invention.
In FIG. 6, reference numeral 108 denotes a noise filter having an input / output integrated structure. The same reference numerals as those in FIG. 1 denote the same components as in FIG.
This embodiment is different from the first embodiment as follows.
That is, the noise filter shown in the first embodiment of FIG. 1 is composed of two noise filters, that is, the input side noise filter 105 and the output side noise filter 102, whereas in the present embodiment, the input side noise filter 105. And the output-side noise filter 102 is constituted by a noise filter 108 having an integrated structure.
Next, the structure of the input / output integrated noise filter 108 of the present invention will be described with reference to FIG.
The input / output integrated structure type filter 108 includes the input noise filter 105 and the output noise filter 102 as a single module and is housed in the integrated structure. The noise current is circulated and confined in the integrated structure, and the noise current is reduced. It is designed not to flow outside the filter.
Since the input side noise filter 105 of the motor driving device 107 and the output side noise filter 102 of the motor driving device 107 are integrated, the common mode current I2 flowing into the AC power supply 100 side and the common mode flowing into the motor 101 are combined. The current I1 can be reduced, the vibration of the common mode current I3 can be reduced, and further downsizing can be realized.

FIG. 7 is an explanatory diagram showing the configuration of the third embodiment of the present invention.
In FIG. 7, reference numeral 109 denotes a motor drive device equipped with a noise filter having an input / output integrated structure, CT denotes a vector control current sensor, and the same reference numerals as those in FIG. 6 denote the same components as in FIG.
The difference of this embodiment from the second embodiment is as follows.
That is, the motor driving device 107 shown in the second embodiment of FIG. 6 has a noise filter 108 having an input / output integrated structure outside thereof, whereas this embodiment is different from the motor driving device 109 in the second embodiment. The noise filter 108 having an input / output integrated structure shown in FIG.
As shown in FIG. 7, the motor driving device 109 is equipped with a noise filter 108 having an input / output integrated structure, and by arranging a vector control current sensor CT on the output side of the output side noise filter, a common mode is achieved. It becomes possible to prevent erroneous detection of current generated due to the influence of current, and vector control as well as V / f control becomes possible.
Further, since the number of noise filter components can be reduced by incorporating the input side noise filter and the output side noise filter in the motor drive device, it is possible to contribute to cost reduction and downsizing.

In particular, when a matrix converter is applied as the motor drive device 109, the matrix converter has a capacitor that is star-connected between the phases of the power input units R, S, and T because of its structure. The bypass circuit unit can be connected to a star-connected capacitor. Therefore, the input side filter can be configured with a small number of parts.
In addition, the matrix converter has features such as "AC-AC direct conversion", "No main circuit electrolytic capacitor", "Power supply regeneration is possible", and "Low input power harmonics". Since it becomes an output voltage current waveform, a more environmentally conscious motor drive device can be realized.

  As described above, in the noise filter according to the present embodiment and the motor driving apparatus equipped with the noise filter, the input side noise filter 105 includes the capacitor Cx Y-connected from each phase of the AC power supply, its neutral point B, and ground. It has a grounding capacitor Cy connected between the parts A, and has a wiring means 106 for electrically connecting the neutral point B and the bypass circuit part E of the output side noise filter 102. Further, since the motor driving device 109 is equipped with a noise filter 108 in which the input side noise filter 105 and the output side noise filter 102 are integrated, a common frequency that flows to the motor and reduces high frequency noise to the power source side. The mode current can be reduced. Furthermore, according to the motor driving device equipped with the noise filter of the present invention, the motor can be driven not only by V / f control but also by vector control, and as a result, the arrangement of the vector control current sensor is changed. It can save time and effort.

  Generated in a motor drive device such as a matrix converter and an inverter by adding the noise filter of the present invention to the motor drive device or using the motor drive device equipped with the input side noise filter and the output side noise filter of the present invention Since noise can be suppressed from flowing out to the power supply side and the motor can be protected at the same time, it can be widely applied to systems that require prevention of malfunction of peripheral devices and long life of the motor.

Explanatory drawing which shows the motor drive device which added the input side noise filter and output side noise filter of this invention The internal block diagram of the input side noise filter 105 of this invention Common mode equivalent circuit diagram of the present invention (FIG. 1) Waveform diagram of the simulation result of each part common mode current in the present invention (FIG. 1) Spectrum diagram of common mode currents I1 and I2 in the simulation of the present invention (FIG. 4) Explanatory drawing which shows the structure of 2nd Example of this invention. Explanatory drawing which shows the structure of 3rd Example of this invention. Explanatory drawing which shows the flow of the common mode electric current of the general motor drive device which a prior art and this invention make object Common Mode Equivalent Circuit Diagram of General Motor Drive Device (FIG. 8) Targeted by Conventional Technology and Present Invention Waveform diagram as a result of simulating the common mode current of each part in the conventional motor drive device (FIG. 8) targeted by the prior art and the present invention Spectral diagrams of common mode currents I1 and I2 in a simulation (FIG. 10) of a general motor driving apparatus targeted by the prior art and the present invention Explanatory drawing which shows the motor drive device using the input side noise filter of a prior art. Internal configuration diagram of prior art input side noise filter Common mode equivalent circuit diagram in the prior art (FIG. 12) Waveform diagram of the simulation result of each part common mode current in the prior art (Fig. 12) Spectrum diagram of common mode currents I1 and I2 in the simulation of the prior art (FIG. 15) Explanatory drawing which shows the motor drive device using the output side noise filter of a prior art Internal configuration diagram of the conventional output side noise filter Common mode equivalent circuit diagram in the prior art (FIG. 17) Waveform diagram of the simulation result of each part common mode current in the prior art (Fig. 17) Spectrum diagram of common mode currents I1 and I2 in the simulation of the prior art (FIG. 20) Explanatory drawing which shows the motor drive device which used the input side noise filter and output side noise filter of the prior art in combination Common mode equivalent circuit diagram in the prior art (FIG. 22) Waveform diagram of the result of simulating each part common mode current in the prior art (FIG. 22) Spectrum diagram of common mode currents I1 and I2 in the simulation of the prior art (FIG. 24)

Explanation of symbols

100 AC power supply 101 Motor
DESCRIPTION OF SYMBOLS 102 Output side noise filter 103 Input side noise filter 105 Input side noise filter by this invention 106 Common line 107 Motor drive device 108 Noise filter of the input-output integrated structure of this invention 109 Motor drive device of this invention 110 Input side noise of prior art Noise filter combining filter and output side noise filter Li, Lo Common mode choke coil Cx, Cy, Cfu, Cfv, Cfw Capacitors Rbu, Rbv, Rbw Resistors I1, I2, I3 Common mode current Vc Common mode voltage

Claims (7)

In the noise filter used with the motor drive device (107) , which comprises an input side noise filter (105) connected to the AC power source (100) and an output side noise filter (102) connected to the motor (101) .
The input side noise filter (105) is connected between a capacitor (Cx) Y-connected from each phase of the AC power source, and a neutral point (B) and a grounding part (A) of the Y-connected capacitor (Cx). Having a grounded capacitor (Cy),
A common line (106) for electrically connecting the neutral point (B) of the Y-connected capacitor (Cx) and the bypass circuit portion (E) of the output side noise filter (102); Noise filter characterized by The noise filter according to claim 1, wherein the noise filter has a structure in which the input side noise filter (105) and the output side noise filter (102) are integrated. The input noise filter (105), an AC power source phase and in series with electrically connected the common mode choke coil (Li), the normal mode noise from the phase of the common mode choke coil (Li) is Y-connection A reduction bypass capacitor (Cx), and a normal capacitor (Cx) electrically connected between the neutral point (B) of the normal mode noise reduction bypass capacitor (Cx) and the grounding part (A). Yes,
The Output Noise Filter (102), the output phase and the electrically connected to the common mode choke coil (Lo) in series, the electric one end to the phase of the common mode choke coil (Lo) of the motor driving device it is connected, the other end bypass circuit portion (E) and electrically connected to bypass capacitors (Cfu, Cfv, Cfw) and damping resistor (RBU, Rbv, Rbw) a series body comprising, that is one having a The noise filter according to claim 1 . The input noise filter (105), the Y neutral point of connection to a capacitor (Cx) (B), and the bypass circuit portion (E) and a for connecting the output side noise filter (102) The noise filter according to claim 1, further comprising a connection terminal (C). The input side noise filter (105) is a filter for reducing a noise terminal voltage;
The noise filter according to any one of claims 1 to 4 , wherein the output-side noise filter (102) is a filter that reduces a common mode current flowing into the motor. In motor drive devices equipped with noise filters,
The mounting to have noise filter, equipped with motor drive device a noise filter, which is a noise filter according to any one of claims 1 to 5. In the motor drive device (109) equipped with a noise filter,
7. The motor driving device equipped with a noise filter according to claim 6, wherein the motor driving device (109) is a matrix converter.