JP2019205298A - Active filter device, air conditioning system, harmonic restraint method, and program - Google Patents

Abstract

To provide an active filter device capable of further enhancing harmonic wave depression effect during driving the air conditioning system with inexpensive configuration.SOLUTION: An active filter device 10 is mounted on an outdoor unit that has an indoor-unit power line PB for supplying AC power from an AC power source 2 to an indoor unit 1B. The active filter device 10 includes: a switching element SW1; an outdoor unit current detection sensor 102 which is arranged so as to detect the current flowing on a rectification circuit 11 toward the output side; and an indoor unit current detection sensor 103 which is arranged so as to detect the current flowing to the power line for indoor unit PB.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an active filter device, an air conditioning system, a harmonic suppression method, and a program.

  In an air conditioning system, it is known to rotate a compressor or the like as desired using an inverter. In such an air conditioning system, harmonics are likely to occur due to the characteristics of the rectifier circuit that converts AC power into DC. For this reason, an active filter is mounted on the outdoor unit side that requires particularly large electric power to suppress harmonics.

  In relation to the active filter described above, Patent Document 1 discloses a current detection unit that detects an alternating current input to the outdoor power supply device and the indoor power supply device, and a harmonic of the alternating current based on the current detection result of the current detection unit. An air conditioner including a harmonic suppression unit that performs control to reduce a wave component is disclosed.

JP 2004-364491 A

  As described above, the outdoor unit is dominant in the power consumed by the air conditioning system. Therefore, normally, the active filter functions to suppress harmonics generated by the operation of the outdoor unit. However, in this case, the harmonics generated based on the operation of the indoor unit are not suppressed at all.

  On the other hand, as in Patent Document 1, in order to suppress the harmonic component of the alternating current input to the entire air conditioning system, when detecting the alternating current input to the outdoor power supply device and the indoor power supply device, the outdoor unit, It is necessary to perform current detection upstream of the branch point of current supply to each indoor unit. If it does so, it will be necessary to prepare the current sensor which can detect a large current, and will cause an increase in manufacturing cost.

  An object of the present invention is to provide an active filter device, an air conditioning system, a harmonic suppression method, and a program that can further enhance the harmonic suppression effect during driving of the air conditioning system with an inexpensive configuration.

  According to the first aspect of the present invention, the active filter device is mounted on an outdoor unit that is connected to an AC power source and has an indoor unit power line for supplying AC power from the AC power source toward the indoor unit. It is an active filter device. The active filter device is a switching element connected so that the output side of the rectifier circuit included in the outdoor unit can be short-circuited, and an outdoor unit current detection sensor installed so as to be able to detect a current flowing to the output side of the rectifier circuit, An indoor unit current detection sensor installed to detect a current flowing through the indoor unit power line, an outdoor unit current is obtained via the outdoor unit current detection sensor, and an indoor unit current is obtained via the indoor unit current detection sensor. And an active filter control unit that performs ON / OFF control of the switching element so that a total current that is a sum of the outdoor unit current and the indoor unit current becomes a sine wave.

  According to the second aspect of the present invention, the outdoor unit current detection sensor detects a current flowing to the output side of the rectifier circuit based on a voltage drop due to a shunt resistor.

  According to the third aspect of the present invention, the indoor unit current detection sensor is a clamp-type current sensor.

  Moreover, according to the 4th aspect of this invention, an air conditioning system is provided with the above-mentioned active filter apparatus.

  Further, according to the fifth aspect of the present invention, the harmonic suppression method is applied to an outdoor unit that is connected to an AC power source and has an indoor unit power line for supplying AC power from the AC power source to the indoor unit. A switching element mounted so that the output side of the rectifier circuit included in the outdoor unit is short-circuitable; an outdoor unit current detection sensor installed so as to be able to detect a current flowing to the output side of the rectifier circuit; It is the harmonic suppression method using an active filter apparatus provided with the indoor unit electric current detection sensor installed so that the electric current which flows into the machine power line can be detected. The harmonic suppression method includes a step of acquiring an outdoor unit current via the outdoor unit current detection sensor, a step of acquiring an indoor unit current via the indoor unit current detection sensor, the outdoor unit current and the indoor unit Performing ON / OFF control of the switching element so that the total current, which is the sum of the currents, becomes a sine wave.

  According to the sixth aspect, the program is mounted on an outdoor unit that is connected to an AC power source and has an indoor unit power line for supplying AC power from the AC power source to the indoor unit. A switching element connected so that the output side of the rectifier circuit can be short-circuited, an outdoor unit current detection sensor installed so as to detect a current flowing to the output side of the rectifier circuit, and a current flowing to the power line for the indoor unit An indoor unit current detection sensor installed to detect the outdoor unit current through the outdoor unit current detection sensor to the computer of the active filter device, and the indoor unit current detection sensor through the indoor unit current detection sensor The step of acquiring the unit current, ON / OFF control of the switching element so that the total current which is the sum of the outdoor unit current and the indoor unit current becomes a sine wave To perform the step of performing.

  According to at least one of the above-described aspects, the effect of suppressing harmonics during driving of the air conditioning system can be further enhanced with an inexpensive configuration.

It is a figure showing the whole air-conditioning system composition concerning a 1st embodiment. It is a figure which shows the processing flow of the active filter control part which concerns on 1st Embodiment. It is a figure for demonstrating the effect | action and effect of the active filter apparatus which concern on 1st Embodiment. It is a figure for demonstrating the effect | action and effect of the active filter apparatus which concern on 1st Embodiment.

<First Embodiment>
Hereinafter, the active filter device according to the first embodiment and an air conditioning system including the active filter device will be described with reference to FIGS.

(Overall configuration of in-vehicle air conditioner control device)
Drawing 1 is a figure showing the whole air-conditioning system composition concerning a 1st embodiment.
The air conditioning system 1 is an air conditioning system including an outdoor unit 1A and an indoor unit 1B. The air conditioning system 1 according to the present embodiment is a so-called packaged air conditioner, and an outdoor unit 1A is connected to an AC power source 2. Here, the AC power source 2 is a normal commercial power system. In this case, the outdoor unit 1A operates based on AC power directly supplied from the AC power supply 2. The indoor unit 1B receives supply of AC power via a power line (an indoor unit power line PB described later) branched from the outdoor unit 1A, and operates based on this.
As described above, the outdoor unit 1A of the air conditioning system 1 according to the present embodiment includes the indoor unit power line PB for supplying AC power from the AC power source 2 to the indoor unit 1B.

  In the following description, in each configuration of the outdoor unit 1A and the indoor unit 1B, the side close to the AC power source 2 is also referred to as “upstream side”, and the side close to the load (compressor motor 13a, etc.). Also referred to as “downstream”.

  As shown in FIG. 1, the outdoor unit 1A includes an active filter device 10, a rectifier circuit 11, inverter circuits 12a and 12b, a compressor motor 13a, and a fan motor 13b. The active filter device 10 includes an active filter control unit 100, an active filter circuit 101, an outdoor unit current detection sensor 102, and an indoor unit current detection sensor 103. Further, the active filter circuit 101 includes a switching element SW1, a reactor L1, a diode D1, and an electrolytic capacitor C1.

The outdoor unit 1 </ b> A is connected to the AC power supply 2 via the power connection terminal T.
The AC power supplied from the AC power source 2 is first transmitted through the main power line P inside the outdoor unit 1A. The main power line P is a power line that transmits AC power (AC current) supplied to the entire air conditioning system 1 (the outdoor unit 1A and the indoor unit 1B). As shown in FIG. 1, the main power line P branches into an outdoor unit power line PA and an indoor unit power line PB on the downstream side.
The outdoor unit power line PA is a power line for transmitting AC power for driving the loads (compressor motor 13a and fan motor 13b) of the outdoor unit 1A among the AC power (AC current) supplied from the AC power source 2. It is.
The indoor unit power line PB is a power line that transmits AC power for driving the load (fan motor 16) of the indoor unit 1B among AC power (AC current) supplied from the AC power supply 2.

  The rectifier circuit 11 of the outdoor unit 1A is a circuit that rectifies AC power transmitted through the outdoor unit power line PA. The rectifier circuit 11 may be, for example, a general diode bridge full-wave rectifier circuit. A high potential after rectification is output from a high potential output line α which is an output line of the rectifier circuit 11. A low potential after rectification is output from the low potential output line β that is an output line of the rectifier circuit 11.

  The inverter circuits 12a and 12b are power conversion circuits for generating desired AC power based on a DC voltage rectified by the rectifier circuit 11 and smoothed by the electrolytic capacitor C1 and the like. The inverter circuit 12a and the inverter circuit 12b are connected in parallel to each other with respect to the high potential output line α and the low potential output line β. The inverter circuit 12a generates AC power for driving the compressor motor 13a to rotate at a desired rotational speed. Further, the inverter circuit 12b generates AC power for driving the fan motor 13b to rotate at a desired rotational speed.

  Next, each configuration of the active filter device 10 mounted on the outdoor unit 1A will be described in detail.

  The active filter control unit 100 is a so-called microcomputer and operates according to a program prepared in advance. The active filter control unit 100 controls ON / OFF of the switching element SW <b> 1 included in the active filter circuit 101 based on a current detection result acquired from an outdoor unit current detection sensor 102 and an indoor unit current detection sensor 103 described later. Specific operation of the active filter control unit 100 will be described later.

The active filter circuit 101 is provided between the rectifier circuit 11 and the inverter circuit 12a (and the inverter circuit 12b).
The electrolytic capacitor C1 of the active filter circuit 101 is connected between the high potential output line α and the low potential output line β of the rectifier circuit 11, and smoothes the voltage rectified by the rectifier circuit 11 to generate a DC voltage.
The switching element SW1 of the active filter circuit 101 connects (short-circuits) between the high potential output line α and the low potential output line β of the rectifier circuit 11 when the switching element SW1 is turned on. When the switching element SW1 is turned on, an electric current instantaneously flows from the high potential output line α to the low potential output line β, but the change in the current is suppressed by the reactor L1. By appropriately switching the switching element SW1 by the active filter control unit 100, the current flowing on the output side (downstream side) of the rectifier circuit 11 is formed as a sine wave as a whole. The diode D1 prevents a backflow of current from the downstream side when the switching element SW1 is turned on.

  The outdoor unit current detection sensor 102 is a resistance element (shunt resistance) installed on the upstream side of the switching element SW1 in the low potential output line β. The voltage drop generated in this resistance element indicates the current flowing to the output side of the rectifier circuit 11 (active filter circuit 101, inverter circuit 12a, compressor motor 13a, etc.). Note that the position where the outdoor unit current detection sensor 102 is disposed is not limited to the present embodiment, and may be provided, for example, on the high potential output line α.

  The indoor unit current detection sensor 103 is a clamp-type current sensor and is installed on the indoor unit power line PB.

Next, the indoor unit 1B will be described.
As shown in FIG. 1, the indoor unit 1 </ b> B includes a rectifier circuit 14, an inverter circuit 15, and a fan motor 16.
The rectifier circuit 14 rectifies AC power supplied from the AC power supply 2 in the same manner as the rectifier circuit 11 provided in the outdoor unit 1A. The voltage rectified by the rectifier circuit 14 is smoothed by the electrolytic capacitor C2 and the reactor L3.
The inverter circuit 15 converts DC power rectified by the rectifier circuit 14 and smoothed by the electrolytic capacitor C2 or the like into desired AC power. The inverter circuit 15 generates AC power for driving the fan motor 16 to rotate.

(Processing flow of active filter controller)
FIG. 2 is a diagram illustrating a processing flow of the active filter control unit according to the first embodiment.
The processing flow shown in FIG. 2 is repeatedly executed regularly by the active filter control unit 100 while the air conditioning system 1 is in operation.

The active filter control unit 100 acquires the current flowing to the output side of the rectifier circuit 11 of the outdoor unit 1A based on the voltage drop generated in the outdoor unit current detection sensor 102 (shunt resistor) (step S01). Hereinafter, the current acquired through the outdoor unit current detection sensor 102 is also referred to as “outdoor unit current”.
Next, the active filter control unit 100 acquires the current flowing through the indoor unit power line PB through the indoor unit current detection sensor 103 (step S02). Hereinafter, the current acquired through the indoor unit current detection sensor 103 is also referred to as “indoor unit current”.
Next, the active filter control unit 100 calculates the total current that is the sum of the outdoor unit current acquired in step S01 and the indoor unit current acquired in step S02 (step S03).
Next, since the total current calculated in step S03 is a sine wave as a whole, the active filter control unit 100 also describes a current to be further flown on the output side of the rectifier circuit 11 (hereinafter referred to as “active filter output current”). .) Is calculated (step S04).
Then, the active filter control unit 100 outputs a switching control signal for turning on / off the switching element SW1 in accordance with the calculated value of the active filter output current obtained in step S04 (step S05).

(Function, effect)
FIG. 3 and FIG. 4 are diagrams for explaining the operation and effect of the active filter device according to the first embodiment, respectively.
First, the operation of the active filter device according to the present embodiment will be described with reference to FIG. Here, the “active filter device in proportion to the proportionality” does not include the indoor unit current detection sensor 103 according to the first embodiment, but based on only the current detected by the outdoor unit current detection sensor 102, It is assumed that the active filter device performs suppression.

The outdoor unit current IA ′ shown in FIG. 3 is the outdoor unit current (current detected by the outdoor unit current detection sensor 102) before application of the active filter device. When the active filter device is not applied, the current flowing on the output side of the rectifier circuit 11 changes sharply and includes harmonics. The comparative active filter device acquires the current through the outdoor unit current detection sensor 102, and performs ON / OFF control of the switching element SW1. Thereby, the outdoor unit current IA formed into a sine wave can be obtained (see the upper diagram in FIG. 3).
However, actually, as shown in FIG. 3, the indoor unit current IB is also a current including harmonics (see the middle diagram in FIG. 3). Therefore, the current (total current I) flowing through the entire air conditioning system 1 includes a harmonic component based on the indoor unit current IB (see the lower diagram in FIG. 3).

  Next, the operation of the active filter device 10 according to the first embodiment will be described with reference to FIG.

  According to the processing flow described in FIG. 2, as shown in FIG. 4, the active filter control unit 100 is active so that the total current I that is the sum of the outdoor unit current IA and the indoor unit current IB becomes a sine wave. The filter circuit 101 is controlled (step S04 in FIG. 2). As a result, the active filter control unit 100 performs switching control so that the outdoor unit current IA has a current waveform obtained by subtracting the indoor unit current IB from the target sine wave.

As described above, according to the active filter device 10 according to the first embodiment, the total current I including the current flowing through the indoor unit 1B is controlled to be a sine wave (see FIG. 4). Therefore, the harmonic suppression effect can be further enhanced.
Further, the active filter device 10 according to the first embodiment includes an indoor unit current detection sensor 103 that can detect only the current flowing through the indoor unit power line PB in the outdoor unit 1A.

Here, when the total current I including the current flowing through the indoor unit 1B is a sine wave, it is considered that the current flowing through the main power line P (see FIG. 1) may be detected. However, since the current flowing through the main power line P is the sum of the currents flowing through both the outdoor unit 1A and the indoor unit 1B, a large current flows. A current sensor capable of detecting a large current is large and expensive, which is disadvantageous in terms of size and cost.
On the other hand, if only the current flowing through the indoor unit power line PB is limited, the clamp-type current sensor can be made small and inexpensive.

  As described above, several embodiments according to the present invention have been described. However, all these embodiments are presented as examples, and are not intended to limit the scope of the invention. The above-described embodiment can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. The above-described embodiments and modifications thereof are included in the invention described in the claims and the equivalents thereof as well as included in the scope and gist of the invention.

DESCRIPTION OF SYMBOLS 1 Air conditioning system 1A Outdoor unit 1B Indoor unit 10 Active filter apparatus 100 Active filter control part 101 Active filter circuit 102 Outdoor unit current detection sensor 103 Indoor unit current detection sensor 11 Rectifier circuit 12a, 12b Inverter circuit 13a Compressor motor 13b Fan motor 14 Rectifier circuit 15 Inverter circuit 16 Fan motor 2 AC power supply T Power supply connection terminal P Main power line PA Outdoor unit power line PB Indoor unit power line SW1 Switching element D1 Diodes L1, L2, L3 Reactors C1, C2 Electrolytic capacitors

Claims (6)

An active filter device mounted on an outdoor unit having an indoor unit power line connected to an AC power source and supplying AC power from the AC power source toward the indoor unit,
A switching element connected so that the output side of the rectifier circuit included in the outdoor unit can be short-circuited;
An outdoor unit current detection sensor installed so as to be able to detect the current flowing to the output side of the rectifier circuit;
An indoor unit current detection sensor installed so as to be able to detect a current flowing through the indoor unit power line;
The outdoor unit current is acquired via the outdoor unit current detection sensor, the indoor unit current is acquired via the indoor unit current detection sensor, and the total current that is the sum of the outdoor unit current and the indoor unit current is a sine wave. An active filter control unit that performs ON / OFF control of the switching element so that
An active filter device comprising: The active filter device according to claim 1, wherein the outdoor unit current detection sensor detects a current flowing to an output side of the rectifier circuit based on a voltage drop due to a shunt resistor. The active filter device according to claim 1, wherein the indoor unit current detection sensor is a clamp-type current sensor. An air conditioning system comprising the active filter device according to any one of claims 1 to 3. Connected to an AC power supply and mounted on an outdoor unit having an indoor unit power line for supplying AC power from the AC power source to the indoor unit, and connected to the output side of the rectifier circuit included in the outdoor unit so as to be short-circuited A switching element, an outdoor unit current detection sensor installed to detect a current flowing to the output side of the rectifier circuit, and an indoor unit current detection sensor installed to detect a current flowing to the power line for the indoor unit, A harmonic suppression method using an active filter device comprising:
Obtaining an outdoor unit current via the outdoor unit current detection sensor;
Obtaining an indoor unit current via the indoor unit current detection sensor;
Performing ON / OFF control of the switching element so that a total current that is a sum of the outdoor unit current and the indoor unit current becomes a sine wave;
Harmonic suppression method having Connected to an AC power supply and mounted on an outdoor unit having an indoor unit power line for supplying AC power from the AC power source to the indoor unit, and connected to the output side of the rectifier circuit included in the outdoor unit so as to be short-circuited A switching element, an outdoor unit current detection sensor installed to detect a current flowing to the output side of the rectifier circuit, an indoor unit current detection sensor installed to detect a current flowing to the power line for the indoor unit, In an active filter device computer comprising:
Obtaining an outdoor unit current via the outdoor unit current detection sensor;
Obtaining an indoor unit current via the indoor unit current detection sensor;
The program which performs the step which performs ON / OFF control of the said switching element so that the total electric current which is the sum total of the said outdoor unit current and the said indoor unit current becomes a sine wave.

Images