JP2006271146A - Inverter device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inverter device which can restrain harmonic components generated in the rear stage of a smoothing meas from being transmitted to the side of an AC power source, without increasing the capacity of a capacitor. <P>SOLUTION: This inverter device is equipped with a rectifying means 2 which rectifies an AC power source 1, a smoothing means 3 where the value of a capacitor is set so that the output voltage from the rectifying means 2 pulsates in a cycle substantially double the frequency of the AC power source, a DC-AC converting means 4 which converts the smoothed voltage into desired AC voltage, and a drive control means 6 which transmits the information for driving the motor 5 to the above DC-AC converting means 4, corresponding to the smoothed voltage; and further, this is provided with a harmonic component removing means 7 on the side of the AC power source 1 rather than the smoothing means 3. This can realize size reduction of the device and reduction in the cost by the reduction of the capacity of the capacitor and the reactor constituting the smoothing means 3, improvement in power factor performance by the enlargement of the current application of the power source, and the higher performance of the power harmonic characteristics of the input current to the smoothing means. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention provides an inverter device for connecting a smoothing means comprising a remarkably small capacitor to an output terminal of a rectifying means and orthogonally transforming a voltage whose output voltage greatly pulsates at twice the frequency of an AC power supply frequency. The purpose is to suppress transmission of electrical high-frequency components generated later in the AC power supply side.

  Conventionally, in an inverter device having a smoothing means composed of this type of small-capacitance capacitor, it is not possible to suppress transmission of an electrical high-frequency component generated at a stage subsequent to the smoothing means to the AC power supply side.

FIG. 3 is an overall configuration diagram of a conventional inverter device. In general, the smoothing means 3 is composed of a large-capacity capacitor and reactor in order to remove an electrical high-frequency component generated after the smoothing means 3 (see, for example, Patent Document 1).
JP 2002-223599 A

  However, the inverter device provided with the smoothing means 3 composed of the conventional small-capacitance capacitor has a problem that the electric high-frequency component generated in the subsequent stage cannot be sufficiently suppressed.

  The present invention solves the above-described conventional problems, and provides an inverter device that can suppress transmission of an electrical high-frequency component generated at the subsequent stage of the smoothing means to the AC power supply side without increasing the capacitor capacity. The purpose is to do.

  In order to solve the above-described conventional problems, an inverter device according to the present invention includes a rectifier that rectifies an AC power supply, and a capacitor value that causes the output voltage from the rectifier to pulsate at approximately twice the frequency of the AC power supply frequency. A set smoothing means, an orthogonal transform means for converting the smooth voltage into a predetermined alternating voltage, and a drive control means for transmitting information for driving the motor in response to the smooth voltage to the orthogonal transform means, A high frequency removing means is provided on the AC power supply side from the smoothing means, whereby an electric high frequency component generated at a subsequent stage of the smoothing means can be provided on the AC power supply side without increasing the capacitor capacity. It is possible to provide an inverter device that suppresses transmission to the.

  ADVANTAGE OF THE INVENTION According to this invention, the inverter apparatus which can suppress transmitting the electrical high frequency component generate | occur | produced in the back | latter stage of a smoothing means to the alternating current power supply side, without increasing a capacitor | condenser capacity | capacitance can be provided.

According to a first aspect of the present invention, there is provided a rectifier for rectifying an AC power supply, a smoothing means in which a capacitor value is set so that an output voltage from the rectifier pulsates at a frequency approximately twice the AC power supply frequency, An orthogonal transforming means for converting to an AC voltage; and a drive control means for transmitting information for driving the motor in response to the smoothing voltage to the orthogonal transforming means, and removing high frequency from the smoothing means to the AC power supply side. In order to suppress transmission of electrical high-frequency components generated in the subsequent stage to the AC power supply side by providing the high-frequency removing means in the previous stage with respect to the smoothing means in the inverter device characterized by providing means, Reduced equipment size and cost by reducing the capacity of capacitors and reactors that make up the smoothing means, improved power factor performance by expanding the power supply width, and rectifying means It is possible to realize a high performance of the power supply higher harmonic characteristic of the input current.

  According to a second aspect of the invention, in the inverter device of the first aspect, the high frequency removing means is constituted by a common mode filter, and does not use a large-capacitance capacitor, and further serves as a reactance component of the reactor constituting the smoothing means. Therefore, it is possible to reduce the size of the device and to improve the power harmonic characteristics of the input current to the rectifying means.

  According to a third aspect of the invention, in the inverter device of the first or second aspect of the invention, the rectifying means is set by setting the resonance frequency obtained from the capacitor and the reactor constituting the smoothing means to be 40 times or more of the AC power supply frequency. High performance of the power supply harmonic characteristics of the input current can be realized.

  The fourth invention is the inverter device according to any one of the first to third inventions, wherein a film capacitor is used as the capacitor constituting the smoothing means, so that the use environment can be selected without worrying about the influence on the life characteristics due to temperature. I can do it.

  According to a fifth aspect of the present invention, by providing the air conditioner with the inverter device according to any one of the first to fourth aspects, the reliability of the capacitor constituting the smoothing means is improved, and the overall size and cost of the device are reduced. Can be realized.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is an overall configuration diagram of an inverter device according to an embodiment of the present invention. The inverter device of FIG. 1 is supplied with electric power from an AC power source 1 such as a commercial power source which is a single-phase AC power source, and includes a rectifying means 2 configured by a diode bridge for full-wave rectification of the supplied AC power source 1, and a common mode. A high frequency removing means 7 constituted by a filter, a smoothing means 3 in which the value of the capacitor is set so that the output voltage from the rectifying means 2 pulsates substantially at a frequency approximately twice the AC power supply frequency, Orthogonal transformation means 4 composed of a plurality of semiconductor switching elements for converting the output voltage into a desired voltage value / frequency for driving the electric motor 5, an electric motor drive command corresponding to a smooth pulsating smooth voltage, It has drive control means 6 composed of a microcomputer that gives a command for synthesizing a speed command at which the rotation speed during one rotation is constant to the orthogonal transform means 4.

  Further, the smoothing means 3 has a small-capacity film capacitor set so that the resonance frequency is 40 times or more of the AC power supply frequency, and a reactor for reducing the peak value of the inrush charging / discharging current to the capacitor. ing.

  Note that the reactor constituting the smoothing means 3 is inserted between the AC power supply 1 and the film capacitor constituting the smoothing means 3, and may be either before or after the rectifying means 2. Further, the reactor takes into consideration a combined component with the reactance component of the common mode filter constituting the high-frequency removing means 7.

  About the inverter apparatus comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  FIG. 2 is an operation waveform of each part in the present embodiment. First, the operation of the conventional inverter device will be described.

  When a commercial power supply with an AC power supply frequency fac = 50 Hz or 60 Hz is used as the AC power supply 1, the output voltage waveform is a sine wave waveform with a period Tac = 20 msec or 16.7 msec as shown in FIG. When this is full-wave rectified by a rectifier 2 composed of a diode bridge in which a plurality of diodes are combined, a full-wave rectified waveform pulsating at a cycle Tac / 2 that is half the power cycle as shown in FIG. Become.

  Next, a waveform obtained by smoothing the full-wave rectified waveform by the smoothing means 3 is shown in FIG. The resonance frequency fc of the reactor and the capacitor constituting the smoothing means 2 is as follows.

  The values of the reactor and the capacitor are set so that the resonance frequency fc is 40 times or more the AC power supply frequency fac. For example, when the AC power supply frequency fac = 50 Hz, if a reactor and a capacitor having a reactance value of 0.5 mH and a capacitance value of 10 μF are used, the resonance frequency fc is as follows.

  By reducing the capacitor capacity of the smoothing means 3 in this way, as shown in FIG. 2 (c), it pulsates greatly in the period Tac / 2 which is half the AC power supply period, as shown in FIG. As shown in FIG. 2 (d), the energization width is increased so that high input power factor and high performance can be realized.

  However, in the configuration of the above conventional inverter device, the electrical high frequency component generated after the smoothing means 3 cannot be removed by the smoothing means 3, and the AC power source 1 side as shown in FIG. Since the electric high frequency component is superposed on the input current, good power supply harmonic characteristics cannot be obtained.

  Therefore, in the inverter device of the present invention, a common mode filter is inserted before the smoothing means 3 as shown in FIG. As a result, the current waveform shown in FIG. 2E is suppressed in which the high frequency component superimposed on the power supply current is suppressed, and high performance of the power supply harmonic characteristics can be realized. Furthermore, the reactor of the smoothing means 3 can be further reduced in capacity by sharing the reactor component of the inserted common mode filter with the reactor of the smoothing means 3.

As described above, in the present embodiment, by providing the high frequency removing means for removing the electrical high frequency component before the smoothing means, a small-capacitance capacitor and reactor can be used to reduce the size and cost of the apparatus. In the inverter device provided with the smoothing means configured, it is possible to realize high performance of the power supply harmonic characteristics of the input current.

  As described above, the inverter device according to the present invention can obtain a good power supply harmonic characteristic while using a smoothing means including a small-capacitance capacitor and a reactor. It can be applied to any inverter device that needs to be realized and to take into consideration the laws and regulations of power supply harmonics.

Block configuration diagram of the inverter device according to the first embodiment of the present invention. (A)-(e) The figure which shows the operation waveform of each part of an inverter apparatus Block diagram of a conventional inverter device

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 AC power supply 2 Rectification means 3 Smoothing means 4 Orthogonal transformation means 5 Electric motor 6 Drive control means 7 High frequency removal means

Claims (5)

Rectifying means for rectifying the AC power supply, smoothing means in which the value of the capacitor is set so that the output voltage from the rectifying means pulsates at approximately twice the frequency of the AC power supply frequency, and orthogonality for converting the smoothed voltage to a predetermined AC voltage Conversion means and drive control means for transmitting information for driving the electric motor corresponding to the smoothing voltage to the orthogonal transform means, and a high frequency removing means is provided on the AC power supply side from the smoothing means. A featured inverter device. 2. The inverter device according to claim 1, wherein a common mode filter is used as the high frequency removing means. 3. The inverter device according to claim 1, wherein the smoothing means includes a capacitor and a reactor, and a resonance frequency required by the capacitor and the reactor is set to be 40 times or more of an AC power supply frequency. The inverter device according to claim 1, wherein a film capacitor is used as the capacitor constituting the smoothing means. The air conditioner provided with the inverter apparatus of any one of Claims 1-4.

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