Refrigerator

Abstract

To reduce power consumption of a control circuit that controls a compressor motor.SOLUTION: A refrigerator 100 comprises a compressor 130, a compressor control circuit 135 that controls the compressor 130, and switch circuits 136, 236, and 336 that turn on and off the supply of power to the compressor control circuit 135.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to the technology of refrigerators.

Background Art

[0002] Techniques for controlling the motor of a refrigerator compressor have been proposed. For example, Japanese Patent Application Laid-Open No. 2002-27777 (Patent Document 1) discloses a torque control method for a motor. In Patent Document 1, when changing the target rotational speed of the motor from low speed to high speed, the width of the torque compensation amount of the torque pattern is temporarily made narrower than a predetermined value, and after reaching the target rotational speed and a predetermined time has elapsed, the torque compensation amount is returned to the predetermined value. A torque control method for a motor has been proposed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to reduce the power consumption by a control circuit for controlling the motor of a compressor.

Means for Solving the Problems

[0005] According to an aspect of the present invention, there is provided a refrigerator including a compressor, a compressor control circuit for controlling the compressor, and a switch circuit for turning on / off the supply of power to the compressor control circuit.

Effects of the Invention

[0006] As described above, according to the present invention, it is possible to reduce the power consumption by a control circuit for controlling the motor of a compressor.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Mode for Carrying Out the Invention

[0008] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed descriptions thereof will not be repeated. [First Embodiment] <Overall Configuration of Refrigerator 100>

[0009] First, with reference to FIG. 1, the overall configuration of the refrigerator 100 according to the present embodiment will be described.

[0010] The refrigerator 100 according to the present embodiment mainly includes a refrigeration cycle 110. The refrigeration cycle 110 mainly includes a compressor 130, a condenser 141, a decompressor 142, an evaporator 143, and a compressor control circuit 135 that controls the drive of the motor of the compressor 130. In addition, the refrigeration cycle 110 is provided with a fan 150 that circulates the cold air generated in the condenser 141 inside the refrigerator 100. And the refrigeration cycle 110 includes a main control circuit 120 for controlling those respective parts.

[0011] More specifically, a voltage is applied to the compressor 130 from a commercial power supply 170 via the compressor control circuit 135. The motor of the compressor 130 is driven and controlled by the output frequency of the compressor control circuit 135.

[0012] The compressor control circuit 135 receives a control signal from the main control circuit 120 and drives the motor by applying a voltage with a predetermined voltage duty and frequency to the motor of the compressor 130.

[0013] The main control circuit 120 includes a CPU (Central Processing Unit) and a memory. More specifically, the CPU executes various processes according to a program stored in the memory. For example, the CPU of the main control circuit 120 calculates the output frequency to the compressor control circuit 135 based on the difference between the set temperature inside the storage compartment input from the user via the in-compartment temperature setting switch 125 and the detected temperature inside the storage compartment input from the in-compartment temperature sensor 126, and inputs a control signal based on the calculation result to the compressor control circuit 135.

[0014] More specifically, when the difference between the set temperature inside the storage compartment and the detected temperature inside the storage compartment is large, the main control circuit 120 sets the output frequency high and increases the driving force of the motor of the compressor 130 via the compressor control circuit 135 to approach the set temperature. On the other hand, when the difference between the set temperature inside the storage compartment and the detected temperature inside the storage compartment is small, the main control circuit 120 sets the output frequency low and reduces the driving force of the motor of the compressor 130 via the compressor control circuit 135. <Configuration of the Compressor Control Circuit 135 for Motor Control>

[0015] Next, with reference to FIG. 2, the configuration for reducing the power consumption of the compressor control circuit 135 according to the present embodiment will be described.

[0016] The refrigerator 100 includes a power supply circuit 101. The power supply circuit 101 generates electric power to be supplied to the compressor control circuit 135 and the fan 150. The power supply circuit 101 includes a DC power supply (not shown), a transformer 160, and a switching power supply IC (Integrated Circuit) 121 (power control circuit).

[0017] The DC power supply converts the AC voltage supplied from the commercial power supply 170 into a DC voltage and outputs it to the transformer 160. Note that the DC power supply may have a boosting function.

[0018] The transformer 160 is an insulated transformer having a primary winding 161, a secondary winding 162, and an auxiliary winding 163. The primary winding 161 is electrically connected to the DC power supply, and a DC voltage is applied thereto. The secondary winding 162 is magnetically coupled to the primary winding 161 via the core. The secondary winding 162 is electrically connected to the motor 151 of the fan 150 via the main control circuit 120. Also, the secondary winding 162 is not electrically connected to the circuit GND of the DC power supply and the primary winding 161. Therefore, the secondary winding 162 is electrically insulated from the DC power supply and the primary winding 161. The auxiliary winding 163 is magnetically coupled to the primary winding 161 via the core. The auxiliary winding 163 is electrically connected to the switching power supply IC 121 and the compressor control circuit 135. Also, the auxiliary winding 163 is electrically connected to the primary winding 161 via the circuit GND of the DC power supply. Therefore, the auxiliary winding 163 is not electrically insulated from the DC power supply and the primary winding 161.

[0019] The switching power supply IC 121 is electrically connected to the primary winding 161 of the transformer 160. The switching power supply IC 121 includes a switching element (for example, a FET (Field Effect Transistor)) electrically connected between one end of the primary winding 161 and the circuit GND. The switching power supply IC 121 controls the current supplied from the DC power supply to the primary winding 161 by driving the switching element on / off. When the switching element turns on / off, an induced electromotive force is generated in the secondary winding 162 and the auxiliary winding 163. The induced electromotive force generated in the secondary winding 162 is supplied to the main control circuit 120 and the fan 150.

[0020] The main control circuit 120 controls the fan 150. For example, the main control circuit 120 controls the rotation speed of the motor 151 of the fan 150 to be the target rotation speed. Note that the control target of the main control circuit 120 is not limited to the fan 150 and includes other units. The rotation speed of the motor of the fan 150 depends on the magnitude of the power supplied from the secondary winding 162. The main control circuit 120 transmits a control instruction signal to the switching power supply IC 121 so that the rotation speed of the motor of the fan 150 becomes the target rotation speed. In other words, the main control circuit 120 transmits a control instruction signal to the switching power supply IC 121 so that the induced electromotive force generated in the secondary winding 162 becomes the target power. In order to maintain electrical insulation between the main control circuit 120 and the switching power supply IC 121, the control instruction signal is transmitted via a photocoupler. Note that in FIG. 2, the illustration of the transmission path of the control instruction signal is omitted. The switching power supply IC 121 controls the switching element based on the control instruction signal from the main control circuit 120, so that the induced electromotive force generated in the secondary winding 162 becomes the target power, that is, the rotation speed of the motor of the fan 150 becomes the target rotation speed. That is, the switching power supply IC 121 performs feedback control on the current flowing through the primary winding 161 so that the power supplied to the fan 150 becomes the target power.

[0021] The auxiliary winding 163 is electrically connected to the switching power supply IC 121 and the compressor control circuit 135 via a diode. The induced electromotive force generated in the auxiliary winding 163 is supplied to the switching power supply IC 121 and the compressor control circuit 135. The switching power supply IC 121 and the compressor control circuit 135 operate using the power supplied from the auxiliary winding 163. Note that, for example, at the time of starting the switching power supply IC 121, such as immediately after the power is turned on to the refrigerator 100, the switching element is driven on / off using the supply power from a DC power supply different from the auxiliary winding 163. Then, after the power supplied from the auxiliary winding 163 becomes stable, the switching power supply IC 121 operates using the supply power from the auxiliary winding 163.

[0022] In addition, the refrigerator 100 of the present embodiment includes a switch circuit 136. The switch circuit 136 is electrically connected between the auxiliary winding 163 and the compressor control circuit 135. The switch circuit 136 is configured to turn on and off the power supply from the power supply circuit 101 (auxiliary winding 163) to the compressor control circuit 135. In the present embodiment, the switch circuit 136 is configured to turn on when the input voltage VCC_I, which is the voltage across both ends of the auxiliary winding 163, is equal to or higher than the threshold value Vth. Specifically, the switch circuit 136 includes a switch element SW1 and an on / off circuit 1361.

[0023] One end of the switch element SW1 is electrically connected to the auxiliary winding 163 via a diode, and the other end is electrically connected to the compressor control circuit 135. In the present embodiment, the switch element SW1 is an n-channel MOSFET (Metal Oxide Semiconductor Field Effect Transistor). The drain of the switch element SW1 is electrically connected to the auxiliary winding 163 via a diode, the source is electrically connected to the compressor control circuit 135, and the gate is electrically connected to the on / off circuit 1361. When the switch element SW1 is in the on state, the connection between the auxiliary winding 163 and the compressor control circuit 135 is conductive, and power is supplied from the auxiliary winding 163 to the compressor control circuit 135. When the switch element SW1 is in the off state, the connection between the auxiliary winding 163 and the compressor control circuit 135 becomes non-conductive, and the power supply from the auxiliary winding 163 to the compressor control circuit 135 is cut off. The on / off of the switch element SW1 is controlled by the on / off circuit 1361.

[0024] The on / off circuit 1361 controls the on / off of the switch element SW1 based on the voltage across both ends of the auxiliary winding 163 (input voltage VCC_I). Specifically, when the input voltage VCC_I is equal to or higher than the threshold value Vth, the on / off circuit 1361 turns on the switch element SW1. In the present embodiment, the on / off circuit 1361 is a series circuit of a resistor R11 and a resistor R12 that are electrically connected between both ends of the auxiliary winding 163. The connection point between the resistor R11 and the resistor R12 is electrically connected to the gate of the switch element SW1. Therefore, a voltage obtained by dividing the input voltage VCC_I with the resistors R11 and R12 is applied to the gate of the switch element SW1. The resistance ratio of the resistors R11 and R12 is set such that when the input voltage VCC_I is equal to or higher than the threshold value Vth, the resistance division value by the resistors R11 and R12 becomes equal to or higher than the on-voltage of the switch element SW1. The setting of the threshold value Vth will be described later.

[0025] As described above, the auxiliary winding 163 is magnetically coupled with the primary winding 161 together with the secondary winding 162. Therefore, the switching power supply IC121 feedback-controls the current flowing through the primary winding 161 so that the power supplied to the fan 150 becomes the target power. As with the induced electromotive force of the secondary winding 162, the induced electromotive force of the auxiliary winding 163 also fluctuates. That is, the voltage across both ends of the auxiliary winding 163 (input voltage VCC_I) fluctuates according to the target rotation speed (target power) of the fan 150.

[0026] Here, the refrigeration cycle 110 of the refrigerator 100 according to the present embodiment has the following properties.

[0027] (1) As an example of an operation of the refrigeration cycle 110, when driving the motor 131 of the compressor 130, loads such as the fan 150 also operate simultaneously in order to circulate the generated cold air in the refrigerator compartment.

[0028] (2) When operating the fan 150, the target rotation speed (target power) of the fan 150 is higher compared to when stopping the fan 150. Therefore, due to the feedback control of the switching power supply IC 121, the voltage across both ends of the auxiliary winding 163 (input voltage VCC_I) also increases.

[0029] Therefore, the above threshold voltage Vth is set to a value lower than the voltage value Vx1 of the input voltage VCC_I during the operation of the fan 150 and higher than the voltage value Vx2 of the input voltage VCC_I when the fan 150 is stopped (Vx1 > Vth > Vx2).

[0030] In this embodiment, when starting the drive of the motor 131 of the compressor 130, first, the main control circuit 120 starts the operation of the fan 150. As a result, the voltage value of the voltage across both ends of the auxiliary winding 163 (input voltage VCC_I) rises from Vx2 (< threshold Vth) to Vx1 (> threshold Vth). When the input voltage VCC_I exceeds the threshold Vth, the switch element SW1 turns on, and the power supply to the compressor control circuit 135 is started. The compressor control circuit 135 is activated by the supply of power and starts the control of the compressor 130. When starting the operation of the compressor 130, if the fan 150 is already operating, since power is already supplied to the compressor control circuit 135, the control of the compressor 130 can be started.

[0031] On the other hand, when the compressor 130 and the fan 150 are stopped, the voltage value of the voltage across both ends of the auxiliary winding 163 (input voltage VCC_I) becomes Vx2 (< threshold Vth). Since the input voltage VCC_I is less than the threshold Vth, the switch element SW1 is in the off state, and no power is supplied to the compressor control circuit 135.

[0032] In this way, in the present embodiment, the switch circuit 136 turns on / off in conjunction with the operation of the fan 150, thereby turning on / off the power supply to the compressor control circuit 135. When operating the compressor 130, since the fan 150 also needs to be operated, power is supplied to the compressor control circuit 135. On the other hand, when stopping the compressor 130 and the fan 150, the power supply to the compressor control circuit 135 is stopped. Thereby, power can be supplied to the compressor control circuit 135 when operating the compressor 130, and the power supply to the compressor control circuit 135 can be stopped when stopping the compressor 130. Therefore, compared with a configuration in which power is always supplied to the compressor control circuit 135 regardless of the operating state of the compressor 130, the power consumption of the compressor control circuit 135 can be reduced. As a result, the power consumption of the refrigerator 100 can be reduced. [Second Embodiment]

[0033] As shown in FIG. 3, the switch circuit 136 of the above embodiment may be replaced with a switch circuit 236 having a constant voltage output function.

[0034] The switch circuit 236 of the present embodiment is electrically connected between the auxiliary winding 163 and the compressor control circuit 135. The switch circuit 236 is configured to turn on / off the power supply from the power supply circuit 101 (auxiliary winding 163) to the compressor control circuit 135. In the present embodiment, the switch circuit 136 is configured to apply a constant output voltage to the compressor control circuit 135 when the input voltage VCC_I, which is the voltage across both ends of the auxiliary winding 163, is equal to or higher than the threshold value Vth. Specifically, the switch circuit 236 includes an on / off circuit 2361 and a constant voltage circuit 2362.

[0035] The on / off circuit 2361 turns on the constant voltage circuit 2362 when the input voltage VCC_I is equal to or higher than the threshold value Vth.

[0036] The constant voltage circuit 2362 has its input terminal electrically connected to the auxiliary winding 163 via a diode, and its output terminal electrically connected to the compressor control circuit 135. When in the on state, the constant voltage circuit 2362 is configured to output a voltage from the output terminal.

[0037] Therefore, when the main control circuit 120 starts the operation of the fan 150, the voltage value of the voltage across both ends of the auxiliary winding 163 (input voltage VCC_I) rises from Vx2 (< threshold value Vth) to Vx1 (> threshold value Vth). When the input voltage VCC_I exceeds the threshold value Vth, the constant voltage circuit 2362 operates and the power supply to the compressor control circuit 135 is started.

[0038] Also, the constant voltage circuit 2362 is configured such that the output voltage output from the output terminal becomes a predetermined voltage value Vx3. More specifically, when the voltage value of the input voltage VCC_I input to the input terminal is equal to or higher than the voltage value Vx3, the constant voltage circuit 2362 steps down the input voltage VCC_I to the voltage value Vx3 and outputs it from the output terminal. The voltage value Vx3 is a value within the allowable range of the input voltage of the compressor control circuit 135.

[0039] Thereby, even when the voltage value of the voltage across both ends of the auxiliary winding 163 (input voltage VCC_I) fluctuates to a value higher than the upper limit value of the input voltage of the compressor control circuit 135, it is possible to suppress the application of an overvoltage exceeding the upper limit value of the input voltage to the compressor control circuit 135. [Third Embodiment]

[0040] As shown in FIG. 4, the switch circuits 136 and 236 of the above embodiment may be replaced with a switch circuit 336 whose on / off is switched by a signal from the main control circuit 120.

[0041] The switch circuit 336 of the present embodiment is electrically connected between the auxiliary winding 163 and the compressor control circuit 135. The switch circuit 336 is configured to turn on / off the power supply from the power supply circuit 101 (auxiliary winding 163) to the compressor control circuit 135. In the present embodiment, the switch circuit 336 is controlled to be turned on / off by the main control circuit 120. The switch circuit 336 includes a switch element SW2 such as an n-channel MOSFET, for example. The switch element SW2 turns on / off based on a control signal from the main control circuit 120. Note that the switch circuit 336 may include a drive circuit that turns on / off the switch element SW2 based on a control signal from the main control circuit 120. In order to maintain electrical insulation between the main control circuit 120 and the switch circuit 336, the control signal is transmitted via a photocoupler.

[0042] In the present embodiment, the main control circuit 120 controls the on / off of the switch circuit 336. Therefore, when stopping the compressor 130, the main control circuit 120 can turn off the switch circuit 336 to stop the power supply to the compressor control circuit 135.

[0043] Also, the main control circuit 120 can control the control of the fan 150 and the power supply to the compressor control circuit 135 separately. Therefore, even when the compressor 130 is stopped and the fan 150 is operated, the switch circuit 336 can be turned off to stop the power supply to the compressor control circuit 135. <Summary>

[0044] In the above embodiment, a refrigerator is provided that includes a compressor, a compressor control circuit that controls the compressor, and a switch circuit that turns on / off the power supply to the compressor control circuit.

[0045] Preferably, the refrigerator further includes a fan, a compressor control circuit, and a power supply circuit that generates power to be supplied to the fan. The power supply circuit includes a transformer including a primary winding, a secondary winding magnetically coupled to the primary winding and electrically connected to the fan, and an auxiliary winding magnetically coupled to the primary winding, and a power supply control circuit that controls the current flowing through the primary winding. The switch circuit is electrically connected between the auxiliary winding and the compressor control circuit.

[0046] Preferably, the power supply control circuit feedback-controls the current flowing through the primary winding so that the power supplied to the fan becomes the target power.

[0047] Preferably, the switch circuit is configured to turn on when the input voltage is equal to or higher than a threshold value.

[0048] Preferably, the switch circuit includes a constant voltage circuit that applies a constant output voltage to the compressor control circuit when the input voltage is equal to or higher than a threshold value.

[0049] Preferably, the refrigerator further includes a main control circuit that controls the fan. The main control circuit controls the on / off of the switch circuit.

[0050] It should be considered that all the embodiments disclosed herein are illustrative and not restrictive in any way. The scope of the present invention is defined by the claims rather than the above description, and it is intended to include all modifications within the meaning and scope equivalent to the claims.

Explanation of Reference Numerals

[0051] 100: Refrigerator 101: Power supply circuit 110: Refrigeration cycle 120: Main control circuit 121: Switching power supply IC 125: In-cabinet temperature setting switch 126: In-cabinet temperature sensor 130: Compressor 131: Motor 135: Compressor control circuit 136: Switch circuit 1361: Off circuit 141: Condenser 142: Pressure reducer 143: Evaporator 150: Fan 151: Motor 160: Transformer 161: Primary winding 162: Secondary winding 163: Auxiliary winding 170: Commercial power supply 236: Switch circuit 2361: Off circuit 2362: Constant voltage circuit 336: Switch circuit R11: Resistor R12: Resistor SW1: Switch element SW2: Switch element

Claims

1. A compressor, a compressor control circuit for controlling the compressor, and a switch circuit for turning on / off the supply of power to the compressor control circuit. A refrigerator comprising the same.

2. A fan, and a power supply circuit for generating power supplied to the compressor control circuit and the fan. The refrigerator further comprises: The power supply circuit includes a transformer having a primary winding, a secondary winding magnetically coupled to the primary winding and electrically connected to the fan, and an auxiliary winding magnetically coupled to the primary winding, and a power supply control circuit for controlling the current flowing through the primary winding. The refrigerator has: The switch circuit is electrically connected between the auxiliary winding and the compressor control circuit. The refrigerator according to Claim 1.

3. The power supply control circuit feedback-controls the current flowing through the primary winding so that the power supplied to the fan becomes the target power. The refrigerator according to Claim 2.

4. The switch circuit is configured to turn on when the input voltage is equal to or higher than a threshold value. The refrigerator according to any one of Claims 1 to 3.

5. The switch circuit includes a constant voltage circuit that applies a constant output voltage to the compressor control circuit when the input voltage is equal to or higher than a threshold value. The refrigerator according to any one of Claims 1 to 3.

6. The refrigerator further comprises a main control circuit for controlling the fan. The main control circuit controls the on / off of the switch circuit. The refrigerator according to Claim 2 or 3.

Images