JP2006296067A - Air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent degradation of characteristics during a decrease in the capacitance of a line-to-ground capacitor, hereinafter referred to as "Y-con". <P>SOLUTION: This air conditioner includes a temperature sensor 21 for measuring an ambient temperature of a noise filter circuit 2. A controller determines whether or not the capacitance of Y-con is on a decrease when the ambient temperature is in excess of a predetermined temperature and compensates for the decrease in the Y-con capacitance by turning on switches 19, 20 of additional Y-con 15 to 18. It is thus possible to prevent Y-con capacitance from decreasing at high temperature and to prevent degradation in the performance of a noise filter circuit even at high temperature without increasing leak current at low temperature. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for preventing performance deterioration due to temperature characteristics of a Y-con of a noise filter circuit in an outdoor unit of an air conditioner.

  FIG. 3 shows an electric circuit of an outdoor unit of a conventional air conditioner. As shown in FIG. 3, an AC power source 1, a bridge rectifier circuit 3 that rectifies the AC power source, a noise filter circuit 2 sandwiched between the AC power source and the bridge rectifier circuit, and a DC terminal connected to the output terminal of the bridge rectifier circuit 3. A smoothing capacitor 4 that smoothes the voltage, an inverter unit 5 that converts the DC voltage smoothed by the smoothing capacitor into a compressor drive power source, and a compressor 6 that is driven by the output of the inverter unit.

  The noise filter circuit is provided for reducing generated noise, and includes a common mode choke coil 7 connected to an AC power source in a common mode, and an X capacitor connected to an input / output terminal to the common mode choke coil. The Y-con 10, 11, 12, and 13 are connected to the ground 14 from each terminal of the common mode choke coil 7.

Among them, the capacitance of Y capacitor in particular has a great influence on the performance of the noise filter circuit.
Japanese Patent Laid-Open No. 11-2335016

  However, the conventional configuration has a problem that the capacity of the Y-con is reduced due to the temperature characteristics of the Y capacitor and the performance of the noise filter circuit is deteriorated.

  The electric circuit of the outdoor unit of the air conditioner is housed in a sealed structure so that insulation does not deteriorate due to the ingress of wind and rain, and the temperature of the components tends to rise, and the temperature rise is further remarkable when the outdoor temperature is high It has become.

  Also, considering the decrease in Y capacitor capacity due to temperature rise, it is possible to prevent the performance of the noise filter circuit from deteriorating by increasing the Y capacitor capacity in advance. And the leakage current increases.

  The present invention solves the above-mentioned conventional problem, and measures the temperature of the noise filter unit, and at the time of high temperature, it is provided with an additional Y capacitor that compensates for the decrease in the capacity of the Y capacitor. It aims at providing the air conditioner which can prevent the performance deterioration of a noise filter circuit.

  In order to solve the above-mentioned conventional problems, the air conditioner of the present invention is provided with a temperature sensor for measuring the ambient temperature of the noise filter circuit, and if the temperature exceeds a preset temperature, the control unit The decrease in capacity is determined, and the additional Y-con switch is turned on to compensate for the decrease in Y-con capacity.

As a result, it is possible to prevent a decrease in the Y capacitor capacity at high temperatures, and it is possible to prevent deterioration in the performance of the noise filter circuit even at high temperatures without increasing leakage current at low temperatures.

  The air conditioner of the present invention can prevent the decrease in Y-con capacity at high temperature by connecting an additional Y-con, and it can prevent noise leakage at high temperature without increasing leakage current at low temperature. Circuit performance deterioration can be prevented.

  In the present invention, an additional Y-con is connected in parallel with the Y-con via a switch, and a temperature sensor that detects the ambient temperature of the noise filter circuit and a control unit that controls on / off of the switch from the detected temperature are provided. When the temperature sensor exceeds the preset temperature, the controller turns on the switch and compensates for the decrease in capacity due to the temperature rise of the Y capacitor by connecting the additional Y capacitor in parallel. Performance degradation can be prevented.

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

(Embodiment 1)
FIG. 1 shows an electric circuit diagram of an outdoor unit of an air conditioner according to Embodiment 1 of the present invention. In FIG. 1, additional Y-cons 15, 16, 17, and 18 are connected to the ground 14 via switches 19 and 20, and the ambient temperature of the noise filter circuit is detected by the temperature sensor 21, and based on the output of the temperature sensor 21. The control unit 22 turns on and off the switches 19 and 20. Constituent elements that are the same as those in the prior art are assigned the same numbers, and detailed descriptions are omitted. The operation and action of the electric circuit of the outdoor unit of the air conditioner configured as described above will be described below with reference to the electric circuit diagram of FIG. 1 and the graph of FIG.

  First, when the ambient temperature of the noise filter circuit 2 detected by the temperature sensor 21 is equal to or lower than the predetermined temperature Ton, the control unit 22 turns off the switches 19 and 20 and only the Y-cons 10, 11, 12, and 13 are used. Is connected to ground 14.

  When the ambient temperature of the noise filter circuit 2 detected by the temperature sensor 21 exceeds the predetermined temperature Ton, the control unit 22 turns on the switches 19 and 20 to connect the additional Y capacitors 15, 16, 17, and 18 in parallel. By connecting, it is possible to compensate for the decrease in capacity of the Y-cons 10, 11, 12, and 13.

As described above, in the present embodiment, when the additional Y capacitors 15, 16, 17, and 18 are connected to the ground 14 through the switches 19 and 20, and the ambient temperature of the noise filter circuit 2 is high,
The controller 22 can turn on the switches 19 and 20 from the output of the temperature sensor 21 to compensate for the decrease in capacity of the Y capacitors 10, 11, 12, and 13, without increasing the leakage current at low temperatures. Moreover, the performance deterioration of the noise filter circuit at high temperatures can be prevented.

  As described above, the air conditioner according to the present invention can prevent performance deterioration due to a temperature change of the noise filter circuit, and thus can be applied to an electric device having a noise filter circuit having the same circuit configuration.

Electric circuit diagram of outdoor unit of air conditioner according to Embodiment 1 of the present invention Temperature characteristic graph of Y capacitor capacity in Embodiment 1 of the present invention Electric circuit diagram of outdoor unit of conventional air conditioner

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 AC power supply 2 Noise filter circuit 3 Bridge rectifier circuit 4 Smoothing capacitor 5 Inverter part 6 Compressor 7 Common mode choke coil 8, 9 X-con 10, 11, 12, 13 Y-con 14 Ground 15, 16, 17, 18 Additional Y Con 19, 20 Switch 21 Temperature sensor 22 Control unit

Claims (1)

A noise filter circuit connected between an AC power source and a bridge rectifier circuit for rectifying the AC power source, a smoothing capacitor connected between output terminals of the bridge rectifier circuit and smoothed to a DC voltage, an inverter unit, and a compressor The noise filter circuit includes a common mode choke coil, two interline capacitors (hereinafter referred to as X capacitors) connected between the input end and the output end of the common mode choke coil, and a terminal of the common mode choke coil. Four line-to-ground capacitors (hereinafter referred to as Y capacitors) each connected to the ground, and four additional Y capacitors connected from the terminals of the common mode choke coil to the ground via switches. A temperature sensor for detecting an ambient temperature of the noise filter circuit, and an output of the temperature sensor. And a control unit for controlling the switch, the ambient temperature of the noise filter circuit is detected by the temperature sensor, and when the ambient temperature becomes high and the capacity of the Y capacitor decreases, the command from the control unit An air conditioner characterized by preventing a decrease in capacity by connecting the additional Y-con by turning on a switch.

Images