JP6282378B2 - Motor drive control device and air conditioner - Google Patents

Description

  The present invention relates to a motor drive control device and an air conditioner that change a reactor connection configuration depending on a difference in input current value.

  2. Description of the Related Art Conventionally, a motor drive control device that is arranged between an AC power supply and a motor and controls driving of the motor generally includes a reactor for the purpose of power supply coordination, power factor improvement, and harmonic suppression. Although this reactor requires an increase in inductance value when the input current value is small, the reactor volume increases. When the input current value is large, it is not necessary to increase the inductance value. It is necessary to suppress the heat generation due to, and the reactor volume increases if the winding is made thicker or the number of turns is increased to suppress the heat generation. That is, it is difficult to reduce the reactor volume regardless of the input current value.

  With respect to such a problem, Patent Document 1 as an example uses two reactors, and changes the connection configuration of these two reactors according to the current setting value, thereby taking an optimum countermeasure against harmonics and reducing the size. The technology which makes a reactor volume small and suppresses the emitted-heat amount is disclosed.

Japanese Patent Laid-Open No. 10-311646

  However, according to the above-described conventional technology, although it is possible to reduce the reactor volume while suppressing the amount of heat generation, it is merely switched whether or not two reactors are connected in parallel. Therefore, there is a problem that there is room for improvement both in the suppression of the heat generation amount and the reduction in the reactor volume.

  The present invention has been made in view of the above, and an object of the present invention is to obtain a motor drive control device capable of effectively suppressing the amount of generated heat and reducing the reactor volume by an input current value.

To solve the above problems and achieve the object, the motor drive control device according to the present invention includes: a rectifier for rectifying and converting an alternating current is connected to an AC power supply into DC, and the AC power supply and the rectifier A current detector that detects an input current from the AC power supply and outputs a detected current value; a first harmonic suppression reactor that is provided at a subsequent stage of the rectifier; and the first harmonic a second harmonic suppression reactor which is provided in parallel with the wave suppression reactor, is pre danger out current input, a command signal according to the comparison result obtained by comparing the with the set current value the detected current value a relay control section that outputs, a relay performing the switch whether the said first harmonic suppression reactor the command signal is inputted second harmonic suppression reactor are connected in parallel, before Symbol Output from the rectifier An inverter circuit for outputting to the motor by converting direct current into alternating current, characterized in that it comprises an inverter control circuit for driving the inverter circuit.

  According to the present invention, it is possible to effectively suppress the amount of generated heat and reduce the reactor volume by the input current value.

The figure which shows an example of the motor drive control apparatus which concerns on Embodiment 1, and its periphery structure. The figure which shows an example of the motor drive control apparatus which concerns on Embodiment 2, and its periphery structure. The figure which shows an example of the motor drive control apparatus which concerns on Embodiment 3, and its periphery structure. The figure which shows an example of the motor drive control apparatus which concerns on Embodiment 3, and its periphery structure.

  Hereinafter, a motor drive control device and an air conditioner according to an embodiment of the present invention will be described in detail based on the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a diagram illustrating an example of a configuration of a motor drive control device and its periphery according to Embodiment 1 of the present invention. A motor drive control device 20 shown in FIG. 1 is connected to a three-phase AC power source 1 to convert AC to DC and rectify it, and is provided between the three-phase AC power source 1 and the rectifier 2 to input current. A current detection unit 3 that detects and outputs a detected current value, a reactor 4 that is a first reactor provided at a subsequent stage of the rectifier 2, and a second that is provided in parallel with the reactor 4 that is a first reactor. A reactor 5 that is a reactor, and a relay control unit 11 that receives a detection current value of the current detection unit 3, compares the detection current value with a set current value, and outputs a command signal according to the comparison result; A relay 6 that switches whether or not the reactor 4 and the reactor 5 are connected in parallel when a command signal is input, a capacitor 7 that smoothes the voltage rectified by the rectifier 2, and a direct current output from the rectifier 2 are exchanged. It is converted to comprise the inverter circuit 10 to be output to the motor 9 and an inverter control circuit 8 for driving the inverter circuit 10. Here, the motor drive control device 20 includes a motor drive control device that is provided in the outdoor unit of the air conditioner and drives the compressor in the outdoor unit, and a motor drive control that is provided in the refrigerator and drives the compressor in the refrigerator. An apparatus can be illustrated. The inverter circuit 10 is provided with a plurality of switching elements. By controlling on / off of these switching elements by a command signal from the inverter control circuit 8, alternating current according to the command signal from the inverter control circuit 8 is generated. Can be output.

  In FIG. 1, when the detection current value of the current detection unit 3 input to the relay control unit 11 is less than the set current value, the relay control unit 11 controls the relay 6 to be turned off so that the reactor 5 is not connected. Then, the harmonics of the input current from the three-phase AC power source 1 are suppressed using only the reactor 4. When the detected current value of the current detection unit 3 is equal to or greater than the set current value, the relay control unit 11 turns on the relay 6 to connect the reactor 4 and the reactor 5 in parallel to reduce the inductance value. However, by dispersing the input current to the reactor 4 and the reactor 5, heat generation due to the resistance component included in the reactors 4 and 5 can be suppressed. Here, the set current value is a value recorded in advance in a memory in the relay control unit 11.

  In this way, the reactors 4 and 5 can be connected in parallel, and heat generation due to the resistance component included in the reactors 4 and 5 can be suppressed. Therefore, reactors 4 and 5 can be reduced in size.

  According to the first embodiment described above, since the heat generation can be suppressed by lowering the combined inductance value and diverting the flowing current, the volume of the reactor can be reduced.

Embodiment 2. FIG.
In the first embodiment, the configuration in which two reactors are provided in the motor drive control device and these can be connected in parallel has been described, but the present invention is not limited to this. In the second embodiment, a configuration in which two reactors are connected in series will be described.

  FIG. 2 is a diagram illustrating an example of a configuration of a motor drive control device according to the second embodiment and its periphery. In the motor drive control device 20a shown in FIG. 2, a relay 6a is provided at the subsequent stage of the reactor 4, a relay control unit 11a that controls the relay 6a when a detection current value of the current detection unit 3 is input is provided, and the relay 6a , Whether or not the reactor 5a is connected in series to the reactor 4 is switched. Specifically, when relay 6a is connected to terminal 6a1, reactor 4 is connected in series with reactor 5a, and when relay 6a is connected to terminal 6a2, the reactor 5a is not connected in series with reactor 4. Other configurations are the same as those in FIG. 1 of the first embodiment.

  In FIG. 2, when the detected current value of the current detection unit 3 is less than the set current value, the relay control unit 11a connects the relay 6a to the terminal 6a1 side so that the output of the reactor 4 is connected in series to the reactor 5a. Switch to. When the detected current value of the current detection unit 3 is equal to or greater than the set current value, the relay control unit 11a sets the relay 6a so that the output of the reactor 4 is connected to the inverter circuit 10 without passing through the reactor 5a. Switch to the terminal 6a2 side. When the reactor 4 and the reactor 5a are connected in series, the inductance value can be increased.

  In this way, the reactors 4 and 5a can be connected in series, and the inductance value can be increased. Therefore, the reactors 4 and 5a can be reduced in size.

  According to the second embodiment described above, since the inductance value can be increased by the series combined inductance, a small reactor can be used, and the volume of the reactor can be reduced.

Embodiment 3 FIG.
In the first and second embodiments, two reactors are provided in the motor drive control device, and the configuration in which these are connected in parallel or the configuration in which they are connected in series has been described. However, the present invention is not limited to these. In the third embodiment, a configuration in which two reactors can be connected in series or in parallel will be described.

  FIG. 3 is a diagram illustrating an example of the configuration of the motor drive control device according to the third embodiment and its periphery. In the motor drive control device 20b shown in FIG. 3, a relay 6 that is a first relay is provided in parallel with the reactor 4, and a relay 6 a that is a second relay is provided after the reactor 4. A relay control unit 11b is provided to input the detected current value and control the relays 6 and 6a. The relay 6 switches whether or not the reactor 5a is connected in parallel to the reactor 4, and the relay 6a is connected to the reactor 4. Whether or not the reactor 5a is connected in series is switched. Other configurations are the same as those in FIG. 1 of the first embodiment.

  In FIG. 3, when the detected current value of the current detection unit 3 is less than the set current value, the relay control unit 11 b turns off the relay 6 and connects the relay 6 a to the reactor 5 a on the terminal 6 a 1 side. By switching to, the reactor 4 and the reactor 5a can be connected in series. When the detected current value of the current detection unit 3 is equal to or greater than the set current value, the relay control unit 11b turns on the relay 6 and switches the relay 6a to the terminal 6a2 side so as to be connected to the inverter circuit 10. Thus, the reactor 4 and the reactor 5a can be connected in parallel. By connecting the reactor 4 and the reactor 5a in series when the detected current value of the current detector 3 is less than the set current value, the inductance value can be increased even if the reactor 4 and the reactor 5a are small. When the detected current value of the current detection unit 3 is equal to or greater than the set current value, heat generation can be suppressed by connecting the reactor 4 and the reactor 5a in parallel to shunt the current. Therefore, the reactors 4 and 5a can be reduced in size.

  As described above, according to the configuration of FIG. 3, the two reactors can be switched between parallel connection or series connection, and the amount of generated heat is effectively suppressed and the reactor volume is effectively reduced by the input current value. It is possible. However, this invention is not limited to the structure shown in FIG. 3, You may control two relays independently.

  FIG. 4 is a modified example of FIG. 3, and is a diagram illustrating an example of the configuration of the motor drive control device according to the third embodiment and its periphery. A motor drive control device 20c shown in FIG. 4 is provided with a relay control unit 11c instead of the relay control unit 11b in FIG. In the configuration shown in FIG. 3, when the relay 6 is turned off, the relay 6a is connected to the terminal 6a1, and when the relay 6 is turned on, the relay 6a is connected to the terminal 6a2. However, in the configuration shown in FIG. 6 and the relay 6a can be controlled independently, the relay 6 can be turned off and the relay 6a can be connected to the terminal 6a2, the relay 6 can be turned on, and the relay 6a can be connected to the terminal 6a1. It is also possible to connect to. When the relay 6 is turned off and the relay 6a is connected to the terminal 6a2, harmonics of the input current from the three-phase AC power source 1 are suppressed using only the reactor 4. When relay 6 is turned on and relay 6a is connected to terminal 6a1, harmonics of the input current from three-phase AC power supply 1 are suppressed using only reactor 5a.

  As described above, according to the configuration of FIG. 4, not only two reactors are connected in parallel or in series, but only one of the two reactors can be connected. The value can be adjusted in four stages. Therefore, it is possible to more effectively suppress the heat generation amount and reduce the reactor volume.

  Here, when the inductance value of the reactor 4 is L4 and the inductance value of the reactor 5a is L5, the combined inductance value Ls when the reactor 4 and the reactor 5a are connected in series is L4 + L5, and the reactor 4 and the reactor 5a are connected in parallel. In this case, the combined inductance value Lp is L4 · L5 / (L4 + L5). Therefore, as an example, when L4> L5, Ls> L4> L5> Lp. Therefore, when the current is small, the reactor 4 and the reactor 5a are connected in series to obtain Ls, and as the current increases, the reactor 4 and the reactor 5 are connected to the reactor L4, the reactor 4 and the reactor 5a. Can be connected in parallel to increase the inductance value and switch to Lp. When reactor 4 and reactor 5a are connected in series, relay 6 is turned off and relay 6a is connected to terminal 6a1, and when only reactor 4 is connected, relay 6 is turned off and relay 6a is connected to terminal 6a1. 6a2, when connecting only the reactor 5a, the relay 6 is turned on and the relay 6a is connected to the terminal 6a1, and when the reactor 4 and the reactor 5a are connected in parallel, the relay 6 is turned on and the relay is connected. What is necessary is just to connect 6a to the terminal 6a2.

  In addition, the motor drive control apparatus concerning Embodiment 1 to Embodiment 4 demonstrated above is applied to the motor which drives the compressor of an air conditioner as an example.

  In the motor drive control devices according to the first to fourth embodiments described above, an example of a relay is an electronic relay and an example of a capacitor is an electrolytic capacitor. However, the invention is not limited to these.

  The configuration described in the above embodiment shows an example of the contents of the present invention, and can be combined with another known technique, and can be combined with other configurations without departing from the gist of the present invention. It is also possible to omit or change the part.

  1 three-phase AC power source, 2 rectifier, 3 current detection unit, 4, 5, 5a reactor, 6, 6a relay, 6a1, 6a2 terminal, 7 capacitor, 8 inverter control circuit, 9 motor, 10 inverter circuit, 11, 11a, 11b, 11c Relay control unit, 20, 20a, 20b, 20c Motor drive control device.

Claims (11)

A rectifier connected to an AC power source to convert AC to DC and rectify,
A current detecting section for outputting a detection current value by detecting the input current from the AC power source provided between the AC power source and said rectifier,
A first harmonic suppression reactor provided at a subsequent stage of the rectifier;
A second harmonic suppression reactor provided in parallel with the first harmonic suppression reactor;
Is entered before dangerous out current value, and a relay control unit for outputting a command signal according to the comparison result obtained by comparing the with the set current value the detected current value,
A relay for switching whether or not the first harmonic suppression reactor and the second harmonic suppression reactor are connected in parallel when the command signal is input ;
An inverter circuit for outputting to the motor by converting the DC output from the previous SL rectifier AC,
A motor drive control device comprising: an inverter control circuit for driving the inverter circuit. Before Symbol command signal,
When the detected current value is less than the set current value, a command to turn off the relay,
When the detected current value is greater than or equal to the set current value, the relay is turned on, and the command signal is used to connect the first harmonic suppression reactor and the second harmonic suppression reactor in parallel. The motor drive control device according to claim 1. A rectifier connected to an AC power source to convert AC to DC and rectify,
A current detecting section for outputting a detection current value by detecting the input current from the AC power source provided between the AC power source and said rectifier,
A first harmonic suppression reactor provided at a subsequent stage of the rectifier;
A second harmonic suppression reactor provided in series with the first harmonic suppression reactor;
Is entered before dangerous out current value, and a relay control unit for outputting a command signal according to the comparison result obtained by comparing the with the set current value the detected current value,
A relay for switching whether or not the first harmonic suppression reactor and the second harmonic suppression reactor are connected in series when the command signal is input ;
An inverter circuit for outputting to the motor by converting the DC output from the previous SL rectifier AC,
A motor drive control device comprising: an inverter control circuit for driving the inverter circuit. Before Symbol command signal,
When the detected current value is less than the set current value, the relay is a command signal for connecting the first harmonic suppressing reactor and the second harmonic suppressing reactor in series,
Wherein when the detected current value is the set current value or more, the first harmonic suppression without the relay and the first harmonic suppression reactor and the second harmonic suppression reactor connected in series the motor drive control device according to claim 3, characterized in that only use a reactor which is a command signal for operating. A rectifier connected to an AC power source to convert AC to DC and rectify,
A current detecting section for outputting a detection current value by detecting the input current from the AC power source provided between the AC power source and said rectifier,
A first harmonic suppression reactor provided at a subsequent stage of the rectifier;
A second harmonic suppression reactor provided in parallel with the first harmonic suppression reactor;
Is entered before dangerous out current value, and a relay control unit for outputting a command signal according to the comparison result obtained by comparing the with the set current value the detected current value,
A first relay for switching whether or not the first harmonic suppression reactor and the second harmonic suppression reactor are connected in parallel when the command signal is input;
A second relay for switching whether or not the first harmonic suppression reactor and the second harmonic suppression reactor are connected in series when the command signal is input ;
An inverter circuit for outputting to the motor by converting the DC output from the previous SL rectifier AC,
A motor drive control device comprising: an inverter control circuit for driving the inverter circuit. Before Symbol command signal,
When the detected current value is less than the set current value, the first relay is turned off, and the second relay is connected to the first harmonic suppressing reactor and the second harmonic suppressing reactor; Is a command signal to connect in series,
When the detected current value is greater than or equal to the set current value, the first relay is turned on, the first harmonic suppression reactor and the second harmonic suppression reactor are connected in parallel, and the first The second relay is a command signal that operates only with the first harmonic suppression reactor without connecting the first harmonic suppression reactor and the second harmonic suppression reactor in series. The motor drive control device according to claim 5.   The motor drive control device according to claim 5, wherein the relay control unit controls the first relay and the second relay independently. The motor drive control device according to any one of claims 1 to 4 , wherein the relay is an electronic relay. The motor drive control device according to any one of claims 5 to 7, wherein the first relay and the second relay are electronic relays. A capacitor for smoothing the voltage rectified by the rectifier;
The motor drive control device according to any one of claims 1 to 7, wherein the capacitor is an electrolytic capacitor. A compressor,
An air conditioner comprising: the motor drive control device according to any one of claims 1 to 9, wherein the compressor is operated by the motor.

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