JP2002081712A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the inconvenience that operating a switching power circuit with a high output and a relatively large power capacity in the state of low power consumption deteriorates the efficiency of the circuit largely and makes it difficult to reduce input power. SOLUTION: Only in the case when especially power consumption is small such as the time of waiting for remote-control signals, power supply to a plurality of load circuits is stopped, and the voltage is lowered. Furthermore, operation of a switching power circuit is thinned out so as to reduce the input power. That is to say, the air conditioner has a power supply cut-off means to the specific load, a voltage lowering means and a means to intermittently turn on and off the switching power source to thin out operation it so as to reduce the mean input power.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to power supply for electrical products, and more particularly to an air conditioner using a standby power system.

[0002]

2. Description of the Related Art An example of a control circuit for an indoor unit and an outdoor unit of an air conditioner and a control power supply for supplying power to the control circuit and a means for reducing standby power are disclosed in, for example, JP-A-2000-9748.
No. 4 publication. Here, the electric power supplied to the control circuits of the indoor unit and the outdoor unit is controlled only by the control power supply of the outdoor unit. FIG. 2 shows the configuration diagram.

The outdoor unit 2-1 is mainly controlled by an air conditioner. The outdoor unit 2-1 includes a compressor 2-2 for controlling a refrigeration cycle, various valves such as an electric expansion valve 2-3, a four-way valve 2-4, and heat. There is a replacement fan motor (outdoor fan) 2-5. Control circuit 2 including microcomputer (microcomputer) 2-10
The DC voltage is supplied to -11 from the control power supply 2-6. On the other hand, the DC voltage obtained by rectifying and smoothing the commercial power supply 2-0 by the converter 2-7 is supplied to the inverter 2-8 to separately control the compressor driving motor.

The microcomputer outputs a command for the number of rotations of the compressor, a command for the number of rotations of the outdoor fan, a command for opening the expansion valve, and a command for switching the four-way valve. Furthermore, an actuator driving amplifier for operating the expansion valve and the four-way valve in accordance with a command from the microcomputer is mounted on the board on which the microcomputer is mounted.

The indoor unit 2-19 includes an outdoor unit 2-1.
Power is supplied from the control power supply 2-6 of the indoor control power supply 2-6.
-15, the control circuit 2-1 including the microcomputer 2-17
8 is supplied with power. Furthermore, it has a heat exchange fan motor (indoor fan) 2-16, a wind direction plate motor 2-13, and a two-way valve 2-14. When the compressor 2-2 is not operated, the power supply to the compressor and the fan motor 2-5 is stopped by turning off the switch 2-12 connecting the commercial power supply 2-0 and the converter 2-7. . The indoor unit 2-19, the inverter 2-8, the fan motor drive circuit 2-9, and the control circuit 2-11 always have a control power supply 2 for the outdoor unit even when the power supply to the compressor is stopped. 6
Supplies DC voltage.

In this method, all control voltages are created by one power supply circuit, and the microcomputers 2-17 and 2-17 of the indoor and outdoor units are used.
If the power supply to the power supply 10 is continued, the voltage is automatically supplied to other control systems.

[0007] Control circuit 2-18 for indoor unit and outdoor unit
11, communication circuits 2-21 for transmitting information to each other;
2-22 are included, and necessary information is passed during driving.

Since there is no need to perform communication during standby, the power consumption of the air conditioner is reduced by reducing the power consumption of the communication circuit.

[0009]

However, in the circuit configuration and the means for reducing the standby power shown in the above technique,
There is a problem that unnecessary power is consumed at a light load such as when the compressor is stopped, that is, at a standby time.
Hereinafter, the reason is specifically described.

When the compressor is stopped, heat exchange of the refrigeration cycle is not performed. Therefore, various valves such as an electric expansion valve for controlling the refrigeration cycle in the air conditioner, and various fan motors for heat exchange and driving of the wind direction plate. Since there is no need to drive at all, there is no need to supply voltage to the various valves, fan motors and the like. The same applies to the communication circuit between the indoor unit and the outdoor unit. Therefore, unnecessary power is given to the load circuit.

Further, the efficiency of the power supply circuit 2-6 decreases as the load becomes lighter, and this becomes more remarkable as a power supply having a larger maximum output power is operated at a lighter load. Here too, unnecessary power is consumed.

FIG. 3 shows a circuit diagram of a conventional switching power supply. Reference numeral 1 denotes a switching transformer, and 2 denotes a switch element, which is turned on when power is supplied to the main winding 3 of the switching transformer 1. Reference numeral 4 denotes a base winding for supplying a voltage for driving the switch element 2, and reference numerals 5 and 6 denote resistors and capacitors of a damper circuit for suppressing the switching noise of the switch element 2. These are resistors, capacitors, and diodes of the clamp circuit for suppressing. Reference numeral 10 denotes a feedback circuit that turns on the pre-driver 10 for turning off the base voltage of the switch element 2.

FIG. 4 shows the waveform of each part. (1) is a current Ic 'flowing through the switch element 2, and (2) is a current Ic'
(3) is the loss generated in the switch element, and (4) is the potential at the output B point of the base winding.

First, in a state where the DC voltage Vd is applied, when the switch element 2 is turned on, Vce becomes 0 V, and a current Ic flows through the main winding 3. Next, the pre-driver 10 is turned on by a signal from the feedback circuit 11, and the switch element 2 is turned off. At this time, a voltage is induced in each of the secondary windings including the base winding 4 to supply power.

When power is completely supplied to the secondary side, the output (B) potential of the base winding 4 rises, and the switching element 2
Turns on.

At this time, when the load current on the output side is large,
The main winding current also increases, and the winding conduction time t2 and the charging time t4 to the secondary load increase. On the other hand, the on / off times t1 and t3 of the switch element 2 are substantially fixed values. Therefore, when the load current is large, the switching cycle T is large, that is, the switching frequency f (= 1/1).
T) decreases and the switching frequency f increases when the load current is small.

Here, the loss (3) of the switch element 2 is:
ON loss Pon and OFF loss Pof during switching operation
f, and saturation loss Psat due to the flow of current.

In particular, the on-loss Pon is a loss determined by an inrush current due to the capacitance components of the damper circuit and the clamp circuit, and is proportional to the switching frequency and becomes a dominant loss at light load.

If the ON loss Pon is not reduced, no matter how much the load power is reduced, the loss of the switch element increases with an increase in the switching frequency f at light load, and the input power is not reduced. Therefore, there is a problem that the input power is not reduced even if the load power is simply reduced.

An object of the present invention is to provide an air conditioner that further reduces power consumption during standby power.

[0021]

In order to achieve the above object, a converter for converting an alternating current connected to a commercial power supply to a direct current, and an inverter for converting a direct current connected to an output stage of the converting means to an alternating current. A refrigeration cycle including a compressor connected to the inverter unit, an outdoor control circuit for controlling the converter unit and the inverter unit, and a plurality of output windings for supplying power to the outdoor control circuit and the indoor unit. An outdoor unit having an outdoor control power supply, an indoor control circuit for controlling heat exchange of the indoor unit and a fan, various motors for driving a wind direction plate, and the like, and an indoor control power supply for supplying power to the indoor control circuit. In the air conditioner constituted by an indoor unit, a switch is provided at any output part of the output winding of the outdoor control power supply, and the switch is turned off at the time of standby, and a specific load is applied. It stops power supply, and among the outdoor control circuit that requires electric power supply comprises a circuit switch that supplies power only circuit having outdoor microcomputer, and the indoor unit.

The voltage supplied to the circuit having the outdoor microcomputer and the indoor unit is lower than the voltage supplied during the normal operation.

Further, in order to reduce the number of times of switching of the switch element of the outdoor control power supply per unit time, the switching power supply is temporally intermittently operated by thinning it out, especially in a state of low power consumption. Means for reducing input power is provided.

A microcomputer for controlling the number of revolutions of the compressor, the number of revolutions of the outdoor fan, the opening of the four-way valve and the expansion valve, and a circuit for driving the four-way valve and the expansion valve based on instructions from the microcomputer are mounted. A control board, a switch provided between a power converter that supplies power to a motor that drives the compressor, and a power supply, the outdoor fan, a drive circuit of the power converter, and power to the control board. And a switch provided between the power supply circuit and the electric motor of the outdoor fan, a switch provided between the power supply circuit and the drive circuit, the microcomputer, After turning off these switches and reducing the power supply circuit voltage,
The microcomputer has a function to stop the clock.

[0025]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of an embodiment of the present invention. The description of the same reference numerals as in FIG. 2 is omitted.

In the outdoor unit 2-1, in order to stop unnecessary power supply during stoppage, the control power supply 2-6 sends an inverter 2-in.
8 while the switch 1-1 is being supplied to the fan motor drive circuit 2-9.
2 is provided. In the indoor unit 2-19, a switch 1-3 is similarly provided in the middle of supplying electric power to the fan motor 2-16.

The transition from the operation to the stop operation will be described below with reference to the flowchart of FIG. First, in Step 1, the microcomputer 2-17 stops the operation of the fan motor 2-16 and the like based on the stop signal received by the remote control light receiving unit 2-20 of the indoor unit 2-19. At the same time, when a stop command is output to the outdoor unit 2-1, the outdoor microcomputer 2-10 stops the converter 2-7, the inverter 2-8, the fan motor drive circuit 2-9, and the like.

Next, in step 2, the microcomputer 2-1
7 turns off the switch 1-3 and stops the supply of control power to the fan motor 2-16.

In step 3, a command to transition to the standby mode is output to the outdoor unit 2-1.

In step 4, the outdoor microcomputer 2-1
0 waits until the output voltage of the converter 2-7 (charge of the smoothing capacitor: not shown) becomes, for example, 10 V or less. This is a preparation for stopping the supply of control power to the inverter 2-8 and the fan motor drive circuit 2-9 connected to the next stage.

In step 5, when the output voltage of the converter 2-7 becomes 10 V or less, the microcomputer 2-10
The switches 1-1 and 1-2 are turned off.

In step 6, the microcomputer 2-10
Sends a command to the control power supply 2-6 to reduce the voltage supplied to the control circuit 2-11 and the indoor unit 2-19 to, for example, １ ／ and to perform the switching operation of the power supply circuit intermittently (thinning operation). Give it. The control circuit 2-11 includes a microcomputer, a communication modem, and an actuator. The microcomputer and the modem operate at 5V. The voltage of the actuator is 12 V. However, since the actuator does not operate during the standby, there is no problem even if the voltage of 12 V is set to 6.5 V. The voltage of the indoor unit 2-19 is 35 V to 20 V.

In step 7, the microcomputer stops the clock oscillation operation of the microcomputer itself. This microcomputer has a function of stopping the clock when a predetermined port is set to “0” and turning on the clock when the port is set to “1”.

According to the above procedure, the supply of power to the circuits (converter 2-7, inverter 2-8, fan motor drive circuit 2-9) that do not require power during the stop is cut off, and the load (control circuit 2 -11, the supply voltage to the indoor unit 2-19) can be reduced, and the power consumption of the microcomputer 2-10 can be reduced.

Next, the transition of the return sequence from the standby mode to the normal operation will be described with reference to the flowchart of FIG.

First, in step 11, the indoor unit 2-
Based on the operation signal received by the 19 remote control light-receiving unit 2-20, a command to cancel the standby mode is output to the outdoor unit 2-1.

Next, at step 12, the microcomputer 2-
17 turns on the switch 1-3 and sets the fan motor 2-16.
Restarts the control power supply.

In step 13, based on the command received from indoor unit 2-19 in step 11, microcomputer 2
-17 restarts the clock oscillation operation.

When the microcomputer 2-10 starts operating, in step 14, the control circuit 2 is supplied to the control power supply 2-6.
−11 and a command to restore the voltage supplied to the indoor unit 2-19 and give a command to continuously perform the switching operation of the power supply circuit (cancellation of the thinning operation of the power supply circuit).
Next, in step 15, the microcomputer 2-10 turns on the switches 1-1 and 1-2, and
-7, inverter 2-8, fan motor drive circuit 2-9
Restarts power supply to the etc.

In step 16, the microcomputer 2-17
Monitors the DC voltage supplied to the indoor unit 2-19 and waits until the voltage becomes, for example, 27 V or more. This is the outdoor unit 2-1
Is to confirm that has returned from the standby mode.

In step 17, the microcomputer 2-17
Operates the fan motors 2-16 and the like,
An operation command is output to the outdoor unit 2-1. Then, the outdoor microcomputer 2-10 operates the converter 2-7, the inverter 2-8, the fan motor drive circuit 2-9, and the like according to the command.

According to the above procedure, the process returns from the standby state with low power consumption.

Next, FIG. 7 shows waveforms at the time of thinning control of the switching power supply.

In the switching during the normal operation, the waveform shown in FIG. 4 is continuously repeated. In step 6 of the flowchart of FIG. 5, when a command to perform thinning is output from the microcomputer to the control power supply 2-6, a switching period T1 and a non-switching period T2 are set.

As shown in FIG. 7, each output voltage rises during the period T1 and falls during the period T2 in which no switching is performed. This voltage drop depends on the capacity of the output smoothing capacitor and the current consumption of the load. The average voltage during the periods T1 and T2 is the power supply applied to each load.

The average voltage applied to the load is controlled by controlling the maximum potential A of the output voltage. For example, in FIG. 1, the outdoor control circuit 2-
What was controlled so that the output to 11 became 12V,
During standby, the maximum potential A is controlled to 7 V so that the average is 6.5 V. By this control, the indoor unit 2-1
The voltage output at 9 was normally 35 V, but about 2 V
The voltage is reduced to 0 V and output. (This takes advantage of the fact that the output of the winding to which feedback is being applied is automatically reduced by automatically reducing the output of the winding wound on the same transformer.) It is intended to realize a system in which is reduced.

[0047]

According to the present invention, it is possible to reduce the input power with an inexpensive configuration even in a low power consumption state where conventional power supply efficiency is significantly reduced, even in a switching power supply circuit having a large power capacity and multiple outputs. Becomes possible.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a control circuit according to the present invention.

FIG. 2 is a control circuit configuration diagram of a conventional air conditioner.

FIG. 3 is a configuration diagram of a conventional switching power supply circuit.

FIG. 4 is a waveform diagram of a conventional switching power supply.

FIG. 5 is a flowchart showing a standby mode transition sequence in the present invention.

FIG. 6 is a flowchart showing a standby mode return sequence according to the present invention.

FIG. 7 is a waveform diagram of a switching power supply according to the present invention.

[Explanation of symbols]

2-0: commercial power supply, 2-1: outdoor unit, 2-2: compressor,
2-3 ... expansion valve, 2-4 ... four-way valve, 2-5 ... fan motor, 2-6 ... control power supply, 2-7 ... converter, 2-8 ...
Inverter, 2-9 ... Fan motor drive circuit, 2-10
... microcomputer, 2-11 ... control circuit, 2-12 ... switch, 2-12 ... fan motor, 2-13 ... wind direction plate motor, 2-14 ... two-way valve, 2-15 ... indoor control power supply, 2-
16 indoor unit, 2-17 microcomputer, 2-18 control circuit, 2-19 indoor unit, 1-1 load switch 1, 1-
2 Load switch 2, 1-3 Load switch 3, 1 Switching transformer, 2 Switch element, 3 Main winding, 4 Base winding, 5 Damper resistor, 6 Damper capacitor, 7 Clamp diode , 8 ... clamp capacitor, 9 ... clamp resistor, 10 ... pre-driver, 11 ...
Feedback circuit.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor, Hirohisa Ogura 800, Tomita, Odai-cho, Shimotsuga-gun, Tochigi Prefecture Inside the Cooling and Refrigerating Business Dept., Hitachi, Ltd. Hitachi, Ltd. Cooling and Heating Division (72) Inventor Kenji Tamura 709 Tomita, Ohira-cho, Shimotsuga-gun, Tochigi Prefecture F-term in Hitachi Tochigi Electronics Co., Ltd. 3L060 AA03 DD06 EE04 3L061 BA03 5G065 AA01 DA06 EA06 FA02 GA04 HA09 JA07 KA02 KA05 LA07 MA01 MA02 MA10

Claims (7)

[Claims] 1. A converter for converting an alternating current connected to a commercial power supply to a direct current, an inverter connected to an output stage of the converter for converting a direct current to an alternating current, and a motor for driving a compressor connected to the inverter. An outdoor control circuit for controlling the converter and the inverter, an outdoor unit having an outdoor control power supply for supplying power to the outdoor control circuit and the indoor unit, and a motor for heat exchange and wind direction driving of the indoor unit. An air conditioner consisting of an indoor control circuit to control and an indoor unit equipped with an indoor control power supply, equipped with a power supply circuit control IC that does not reduce power efficiency at low power consumption, and supplies power to other than indoor and outdoor control microcomputers An air conditioner that controls a microcomputer with low power without reducing the power efficiency even when the power supply is stopped. 2. The air conditioner according to claim 1, wherein the switching operation of the switching power supply is thinned out as means for preventing the power supply efficiency from decreasing. 3. The air conditioner according to claim 1, wherein the indoor microcomputer is connected to an infrared light receiving circuit from a remote controller, and the outdoor microcomputer is connected to a communication circuit connecting the indoor and outdoor microcomputers. 4. The air conditioner according to claim 2, further comprising a circuit for stopping power supply to a circuit that does not operate in a low power consumption state. 5. The air conditioner according to claim 2, further comprising a circuit for lowering a voltage supplied to an operating circuit in a state of low power consumption as compared with a normal state. 6. The air conditioner according to claim 2, wherein the air conditioner has a function of stopping a clock oscillation operation of the outdoor microcomputer in a low power consumption state. 7. A microcomputer for controlling the number of revolutions of the compressor, the number of revolutions of the outdoor fan, the opening of the four-way valve and the expansion valve, and a circuit for driving the four-way valve and the expansion valve based on instructions from the microcomputer. A control board, a switch provided between a power converter that supplies power to a motor that drives the compressor, and a power supply, the outdoor fan, a drive circuit of the power converter, and power to the control board. And a switch provided between the power supply circuit and the electric motor of the outdoor fan, a switch provided between the power supply circuit and the drive circuit, the microcomputer, An air conditioner having a function of turning off these switches, lowering the power supply circuit voltage, and stopping the clock of the microcomputer.