JP3827927B2 - Inverter device and refrigerator equipped with this device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to load operation control of an inverter device that drives a load such as an electric motor for a compressor used in a refrigeration system such as a refrigerator.
[0002]
[Prior art]
In recent years, in an inverter device used for a refrigerator or the like, the applied voltage is changed depending on the operation state of the compressor, and the operation efficiency during low-speed rotation of the compressor is improved.
[0003]
A conventional inverter device is disclosed in Japanese Patent Application Laid-Open No. 11-32498.
[0004]
Hereinafter, the conventional inverter device will be described with reference to the drawings.
[0005]
FIG. 7 is a block diagram of a conventional inverter device. The conventional inverter device has the following seven components.
[0006]
(1) An AC power source (commercial 100V) 1 is rectified and smoothed by a converter 10 and then switched by a three-phase bridge-connected semiconductor switch (transistor) or the like to armature windings of a three-phase brushless motor 4 An inverter circuit 3 to be applied to
(2) The semiconductor switches (transistors) Ua, Va, Wa, X, Y, and Z of the inverter circuit 3 are turned on and off by a signal output from the control circuit 11 based on the position detection signal from the position detection circuit 5 A drive circuit 7 to be driven;
(3) Converter 10 having a full-wave rectifier circuit 2a, a voltage doubler circuit 2b, a smoothing capacitor 2c, and a mode switching circuit 10a that disables the voltage doubler operation between the full-wave rectifier circuit 2a and the voltage doubler circuit 2b. When,
(4) A rotation speed calculation unit 11a that calculates the rotation speed of the brushless motor 4 based on a position detection signal from the position detection circuit 5, and whether to switch to the voltage doublerless mode of the voltage doubler circuit 2b based on this rotation speed A mode determination unit 11b for determining whether
(5) A mode switching unit 11c that controls the mode switching circuit according to this mode determination, and issues a variable instruction of the duty of PWM chopping;
(6) A timer 11d for prohibiting mode switching for a certain period of time, a duty setting unit 11e for changing the on-time width of PWM chopping in accordance with the duty variable instruction, and a drive signal in which chopping is superimposed on the energization timing A control circuit (microcomputer) 11 having a waveform generator 11f for generating;
(7) A driver 12 that drives the mode switching circuit 10 by a control signal from the control circuit 11 is provided.
[0007]
About the inverter apparatus comprised as mentioned above, the operation | movement is demonstrated below.
[0008]
First, AC 100V AC power from a commercial power source is rectified and smoothed by the converter 10, and these form a voltage doubler rectifier circuit by turning on the mode switching circuit 10a, and form a full-wave rectifier circuit by turning it off. The DC voltage applied to the inverter circuit 3 is about 280V when the mode switching circuit 10a is on and no more than 140V when the mode switching circuit 10a is off when there is no load.
[0009]
This DC voltage is supplied to the inverter circuit 3 and is chopped with a PWM signal of several kHz to several tens of kHz to supply the required power to the brushless motor 4. A PWM signal for controlling on / off of a semiconductor switch which is a component of the inverter circuit 3 is generated by a control circuit 11 including a microcomputer or the like.
[0010]
Further, during high speed rotation, the voltage applied to the inverter circuit 3 is increased by turning on the mode switching circuit 10a, and during low speed rotation, the voltage applied to the inverter circuit 3 is decreased by turning off the mode switching circuit 10a. Here, for example, when the motor 4 is decelerated from high speed rotation to low speed rotation, the voltage applied to the inverter circuit 3 is changed from about 280 V (no load condition) to 140 V by turning off the mode switching circuit 10a. A command is given from the control circuit 11 to the inverter circuit 3 so as to decelerate the rotational speed of the motor 4 after the pressure is reduced to a certain degree (no-load condition).
[0011]
[Problems to be solved by the invention]
However, since the conventional configuration does not include means for gently transforming the voltage applied to the inverter circuit 3, such as a circuit for detecting the zero cross of the AC power supply 1, a full-wave rectifier circuit and a voltage doubler rectifier circuit are provided. Is switched instantaneously by the mode switching circuit 10a, and the voltage applied to the inverter circuit 3 is instantaneously boosted. Therefore, since a very large current flows, a switch means having a large current capacity is required, and there is a drawback that the switch means is enlarged.
[0012]
Further, when the voltage applied to the inverter circuit 3 is changed, the motor 4 is switched after the voltage applied to the inverter circuit 3 is switched from the double voltage rectification to the full wave rectification in order to decelerate the motor 4 from high speed rotation to low speed rotation, for example. To slow down. Here, even when the applied voltage of the inverter circuit 3 is a double voltage, the electric power that can be supplied to the motor 4 is reduced with the applied voltage of the inverter circuit 3 even when the rotation speed is full voltage. . For this reason, the rotational speed of the motor 4 cannot reach the rotational speed, and the control circuit 11 issues a command for the motor 4 to operate at the maximum rotational speed that can be realized in the environment. In this state, the motor 4 continues to rotate.
[0013]
Furthermore, if the applied voltage or load of the inverter circuit 3 fluctuates during operation with the motor 4 rotating at an indefinite state, the motor 4 fluctuates so that abnormal noise and noise are generated. It was.
[0014]
The present invention solves the conventional problem, and by providing a circuit for detecting the zero crossing of the AC power supply, a gradual transformation is realized by the non-contact switch means when the voltage applied to the inverter circuit is transformed, and at the time of the double voltage Switching to mechanical switch means with low power loss realizes downsizing of the switch means, and considering the number of revolutions of the motor, the transformer is rotating at a speed that can be reached even after transformation. The purpose is to do.
[0015]
Further, since there is no means for gently transforming the voltage applied to the inverter circuit 3 such as a circuit for detecting the zero cross of the AC power supply 1, switching between the full-wave rectifier circuit and the voltage doubler rectifier circuit is possible. 10a is performed instantaneously. In other words, the voltage applied to the inverter circuit 3 is instantaneously boosted, and a very large current flows. Therefore, a switch means having a large current capacity is required, and the switch means becomes large.
[0016]
Further, when the motor is rotated at a higher speed, the mode switching circuit 10a switches from the full-wave rectifier circuit to the voltage doubler rectifier circuit in an instant, so that the motor speed is accelerated and applied to the inverter circuit 3. The voltage that rises sharply increases, the motor rotates too much higher than the target rotation speed, and it is impossible to control the passage time and passage time of the resonance point inherent to the compressor, and it is impossible to suppress abnormal noise and noise There was a drawback of becoming.
[0017]
Another object of the present invention is to provide a circuit for detecting the zero crossing of an AC power supply so that a gradual voltage transformation is realized by the non-contact switch means when the voltage applied to the inverter circuit is transformed, and a machine with a small power loss at the double voltage. The switch means can be reduced in size by switching to the type switch means, and when rotating the motor at a higher speed, the rotation speed is accelerated with the applied voltage constant, and the applied voltage is boosted at a constant rotation speed. In this state, it is possible to control the passage time and the passage time of the resonance point.
[0018]
Further, since there is no means for gently transforming the voltage applied to the inverter circuit 3 such as a circuit for detecting the zero cross of the AC power supply 1, switching between the full-wave rectifier circuit and the voltage doubler rectifier circuit is possible. 10a is performed instantaneously, that is, the voltage applied to the inverter circuit 3 is boosted instantaneously. Therefore, since a very large current flows, a switch means having a large current capacity is required, and there is a drawback that the switch means is enlarged.
[0019]
In addition, when the motor is rotated at a lower speed, the mode switching circuit 10a switches from the voltage doubler rectifier circuit to the full-wave rectifier circuit in an instant. The applied voltage also drops steeply, causing the motor to become too lower than the target rotational speed, and in some cases below the lower limit of the rotational speed at which the motor can be refueled, resulting in excessive wear on the motor. It was.
[0020]
Another object of the present invention is to provide a circuit for detecting the zero crossing of an AC power supply so that a gradual voltage transformation is realized by the non-contact switch means when the voltage applied to the inverter circuit is transformed, and a machine with a small power loss at the double voltage. The switch means can be downsized by switching to the automatic switch means, and when the motor is rotated at a lower speed, the rotation speed is decelerated with the applied voltage constant, and the applied voltage is stepped down at a constant rotation speed. By performing in this state, it is possible to control the normal rotational speed so that it does not greatly fall below the target rotational speed.
[0021]
Further, as described above, when the voltage applied to the inverter circuit 3 is transformed, the rotational speed is constant. However, if transformation is performed with an inappropriate rotational speed such as the vicinity of the lower limit value of the refuelable rotational speed, There was a drawback that oil supply to the motor became impossible due to load fluctuations and voltage fluctuations.
[0022]
Another object of the present invention is to maintain a better operation of the electric motor by setting the rotation speed when transforming the applied voltage to an appropriate rotation speed that is sufficiently faster than the lower limit value of the refuelable rotation speed. It is to be.
[0023]
Furthermore, the other object of this invention is to improve the reliability of the refrigerator using an inverter apparatus.
[0024]
[Means for Solving the Problems]
The invention according to claim 1 of the present invention includes a rectifying / smoothing circuit that converts input AC power having a constant voltage into DC power, and the DC power converted by the rectifying / smoothing circuit is converted into required power for compression. A load power supply module that supplies a load such as a motor for a machine, a drive unit that drives the load power supply module, a position detection circuit that detects a rotation speed of the motor, and a rectification / smoothing circuit that are full-wave. Mechanical switch means for switching between a rectifier circuit and a voltage doubler rectifier circuit, and non-contact switch means for gently changing the voltage applied to the load power supply module when the mechanical switch means switches the rectifier / smoothing circuit And an inverter device having a controller for commanding transformation of the voltage applied to the power supply module for load, speed change of the motor, and the like. When changing the applied voltage to the load power supply module in the range of full-wave rectification to voltage doubler rectification as the rotational speed of the electric motor is changed, before and after changing the voltage The controller commands the load power supply module so that it can be operated at any applied voltage, and changes the voltage while operating the motor at the rotational speed. Since the motor can be rotated at a stable rotational speed later, the rotational speed does not become unstable with respect to relatively small voltage fluctuations and load fluctuations, and it is possible to realize rotational speed control that does not generate abnormal noise or noise. Has an effect.
[0025]
According to a second aspect of the present invention, there is provided a rectifying / smoothing circuit that converts input AC power having a constant voltage into DC power, and a DC motor converted by the rectifying / smoothing circuit into required power so as to be used as an electric motor for a compressor. A power supply module for a load to be supplied to a load, a drive means for driving the power supply module for a load, a position detection circuit for detecting a rotation speed of the electric motor, and a full-wave rectification circuit as the rectification / smoothing circuit Mechanical switch means for switching to a voltage doubler rectifier circuit, contactless switch means for gently changing the voltage applied to the load power supply module when the mechanical switch means switches the rectification / smoothing circuit, In an inverter device having a controller for commanding transformation of applied voltage to a power supply module for load, shifting of rotation speed of the electric motor, etc. When the voltage applied to the load power supply module is boosted in the range of full-wave rectification to voltage doubler rectification as the electric motor is rotated at a higher speed, the controller instructs the load power supply module to apply the voltage. Shifting the motor with a constant voltage, boosting the applied voltage with a constant rotation speed of the motor, and controlling the passage time and passage time of the resonance point inherent to the compressor As a result, the noise and noise can be minimized.
[0026]
According to a third aspect of the present invention, there is provided a rectifying / smoothing circuit that converts input AC power having a constant voltage into DC power, and a DC motor converted by the rectifying / smoothing circuit into required power so as to be used as an electric motor for a compressor. A power supply module for a load to be supplied to a load, a drive means for driving the power supply module for a load, a position detection circuit for detecting a rotation speed of the electric motor, and a full-wave rectification circuit as the rectification / smoothing circuit Mechanical switch means for switching to a voltage doubler rectifier circuit, contactless switch means for gently changing the voltage applied to the load power supply module when the mechanical switch means switches the rectification / smoothing circuit, In an inverter device having a controller for commanding transformation of applied voltage to a power supply module for load, shifting of rotation speed of the electric motor, etc. When the voltage applied to the load power supply module is stepped down in the range of full-wave rectification to voltage doubler rectification as the motor is rotated at a lower speed, the controller instructs the load power supply module to apply Rotation speed at which the motor is shifted while the voltage is constant, and the applied voltage is stepped down while the rotation speed of the motor is constant, and the rotation speed at which regular rotation speed control is possible and the motor can be lubricated The lower limit of the value is not reduced, and the motor wear can be minimized.
[0027]
According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, when the voltage applied to the load power module is changed as the rotational speed of the motor is changed. In addition, the rotation speed of the motor is changed to an intermediate speed which is a more preferable rotation speed at the time of transformation, and the transformation is performed after reaching the intermediate speed, and the rotation speed at which the applied voltage is transformed can be refueled. By setting an optimum speed such as a rotational speed sufficiently faster than the lower limit value of the speed, there is an effect that the electric motor can be maintained in a better operating state.
[0028]
Invention of Claim 5 is a refrigerator using the inverter apparatus as described in any one of Claims 1-4, Comprising: It is a refrigerator using the invention of Claim 1 and Claim 2. If there is, it will prevent the refrigerator user from having anxiety and distrust about whether the refrigerator is out of order by eliminating noise and noise related to the operation of the compressor motors that make up the refrigeration system. By improving the reliability of the refrigerator. Moreover, if it is a refrigerator using invention of Claim 3 and Claim 4, the excessive abrasion of the electric motor of a compressor can be suppressed, a longer-term lifetime can be ensured, and the reliability of a refrigerator will be improved.
[0029]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an inverter device according to the present invention and an embodiment of a refrigerator equipped with the device will be described with reference to the drawings.
[0030]
(Embodiment 1)
FIG. 1 is a block diagram of an inverter device according to Embodiment 1 of the present invention, and FIG. 2 is a timing chart showing the operation of the embodiment.
[0031]
In FIG. 1, reference numeral 21 denotes a rectifier circuit, which is composed of four rectifier diodes, rectifies input AC power having a constant voltage and outputs the rectified circuit to the smoothing circuit 23.
[0032]
22 is a switch means, which is composed of a TRIAC (non-contact switch means) 22a and a relay (mechanical switch means) 22b connected in parallel, and ON / OFF is switched by a signal output from the controller 29, The voltage output to the smoothing circuit 23 is changed to a peak value when there is no load in a range from 140 V to 280 V (in this embodiment, the voltage value of the input AC power is AC 100 V). However, although the two switch means 22 are made into the triac 22a and the relay 22b here, it is not necessarily the limitation.
[0033]
A smoothing circuit 23 is composed of two smoothing capacitors connected in series. The voltage rectified by the rectifying circuit 21 is smoothed and output as DC power to a load power supply module 24 described later.
[0034]
Reference numeral 24 denotes a load power supply module, in which a semiconductor switch (transistor) is connected in a three-phase bridge, and a diode is connected to each transistor in parallel and in the reverse direction. The DC power output from the smoothing circuit 23 is converted into required power and supplied to a load (an electric motor 25 described later).
[0035]
Reference numeral 25 denotes an electric motor which is operated at a required rotational speed by the output of the load power supply module 24.
[0036]
Reference numeral 26 denotes a zero-cross detection circuit, which is composed of an integrated circuit (op-amp) or the like, and detects when the voltage value of the input AC power becomes 0 V and outputs an appropriate phase control drive signal to the triac drive circuit 27. The input AC zero cross signal is output to the controller 29.
[0037]
Reference numeral 27 denotes a triac drive circuit, which appropriately turns on / off the triac according to the phase control drive signal output from the controller 29.
[0038]
An applied voltage detection circuit 28 detects a voltage applied to the load power supply module 24 and outputs an applied voltage detection signal to the controller 29.
[0039]
Reference numeral 29 denotes a controller, which is composed of a microcomputer, a waveform generation circuit that is a driving means of the load power supply module 24, and the like. The input / output of various signals described above, the relay drive signal output to the relay drive circuit 30, Based on the signal output from the position detection circuit 31, the rotational speed of the electric motor 25 is monitored.
[0040]
Reference numeral 30 denotes a relay drive circuit, which includes a semiconductor switch and the like, and appropriately controls ON / OFF of the relay by a relay drive signal output from the controller 29.
[0041]
Reference numeral 31 denotes a position detection circuit which detects the position of the rotor of the electric motor 25 and outputs it to the controller 29.
[0042]
The two switch means 22a and 22b are selectively used depending on the operation. When the voltage applied to the load power supply module 24 is transformed, the controller 29 turns the TRIAC 22a on and off by phase control based on the signal from the zero-cross detection circuit 26, and gradually transforms the voltage.
[0043]
In addition, when the electric motor 25 is operated at a high speed higher than an arbitrary rotational speed, it is necessary to supply a large electric power to the electric motor 25. Therefore, the controller 29 outputs a signal to the relay drive circuit 30 and turns on the relay 22b. Thus, a voltage doubler rectifier circuit is configured, and a voltage of about 280 V is applied to the load power supply module 24 as a peak value at no load.
[0044]
On the other hand, when the motor 25 is operated at a low speed less than an arbitrary rotational speed, not much power is required. Therefore, the relay 22b is turned off and a full-wave rectifier circuit is configured by a command from the controller 29. A voltage of about 140 V is applied to the load power supply module 24 at the peak value during loading.
[0045]
The operation of the inverter device configured as described above and the refrigerator provided with this device will be described below with reference to FIG.
[0046]
In a device such as a refrigerator (not shown) having an inverter device, in order to operate a load such as the electric motor 25 more efficiently, a voltage applied to the load power supply module 24 is a load state such as a rotation speed of the electric motor 25. Change by. For example, when the electric motor 25 is rotated at a high speed, the voltage is switched to a double voltage, and when the electric motor 25 is rotated at a low speed including a stop time, the voltage is approximately half of that. To supply.
[0047]
For example, when the voltage of about 280V is applied to the load power supply module 24 by configuring the voltage doubler rectifier circuit by turning on the relay 22b, the applied voltage cannot be realized with the voltage of about 140V. A case where the electric motor 25 is operated at such a high speed rotation will be described.
[0048]
As the temperature in the refrigerator approaches the target temperature, the controller 29 gives a command to turn off the relay 22b before the rotation speed of the motor 25 is reduced. In order to realize the rotation speed commanded by the controller 29, the electric power supplied to the electric motor 25 is insufficient, so the electric motor 25 cannot reach the rotation speed, and the operation is continued at an indefinite rotation speed. Will continue.
[0049]
Next, the operation of the inverter device according to the present embodiment will be described with reference to FIG.
[0050]
At the time t1 when an opportunity to decelerate the speed of the electric motor 25 has occurred, such as when the temperature in the refrigerator has approached the target temperature, a command for a rotational speed lower than the upper limit value of the speed that can be rotated at all voltages is sent from the controller 29 to the electric motor. 25. Then, the controller 29 detects the rotational speed of the electric motor 25 based on the signal obtained from the position detection circuit 31.
[0051]
The controller 29 starts to step down the voltage applied to the load power supply module 24 at time t3 after the electric motor 25 reaches the command rotational speed (time t2). Further, the controller 29 gives a signal for turning off the relay 22b to the relay drive circuit 30. At the same time, the controller 29 gives a phase control drive signal to the triac drive circuit 27 so that the triac 22a repeats ON / OFF.
[0052]
Then, after the controller 29 detects that the applied voltage of the load power supply module 24 has reached the full voltage at time t4 based on the signal sent from the applied voltage detection circuit 28, Stop the signal completely. Further, until the time t3, that is, while the double voltage is applied to the load power supply module 24, the relay 22b is ON and the triac 22a is OFF.
[0053]
As a result, the rotational speed of the electric motor 25 becomes lower than the upper limit value of the speed that can be rotated at all voltages before the time t4 when the voltage applied to the load power supply module 24 reaches the full voltage. Therefore, there is no need to operate at an indefinite rotational speed, and normal rotational speed control is performed, so that the rotational speed does not become unstable even if some load fluctuation or voltage fluctuation occurs. . Further, only the relay is turned on at the time of voltage doubler, and the relay is turned off at the time of voltage transformation to operate only the triac, thereby realizing an operation in which the current becomes smaller.
[0054]
As described above, when the voltage applied to the load power supply module 29 is transformed, the inverter device according to the present embodiment has the electric motor 25 before giving a command to the switch means 22 (here, the triac 22a and the relay 22b). By changing the rotational speed of the motor, it is possible to realize rotational speed control that does not cause indefinite noise and noise without causing the rotational speed to become unstable. Further, only the relay 22b is turned on when the voltage is doubled, and only the triac 22a is operated when transforming the voltage, whereby the switch means 22 can be reduced in size.
[0055]
In addition, regarding the operation of the electric motor 25 of the compressor constituting the refrigerator refrigeration system, the refrigerator user can have anxiety and distrust about whether the refrigerator is out of order by eliminating noise and noise. By preventing this, the reliability of the refrigerator can be improved.
[0056]
(Embodiment 2)
FIG. 3 is a timing chart showing the operation of the inverter device according to the second embodiment of the present invention.
[0057]
In the present embodiment, when the rotation speed of the electric motor 25 is further increased, the voltage applied to the load power supply module 24 is increased after the boosting is completed. A function to increase the rotation speed is provided.
[0058]
The operation of the inverter device configured as described above will be described below with reference to the timing chart of FIG.
[0059]
At the time tU1 when an opportunity to accelerate the speed of the electric motor 25 such as a quick freeze command by the user has occurred, the controller 29 gives a phase control drive signal to the triac drive circuit 27 so that the triac 22a repeats ON / OFF, Boosting of the voltage applied to the load power supply module 24 is started.
[0060]
Based on the signal output from the applied voltage detection circuit 28, the controller 29 detects that the applied voltage of the load power supply module 24 has reached the double voltage at time tU2, and causes the relay drive circuit 30 to turn on the relay 22b. give.
[0061]
After the relay 22b is turned on, at time tU3, the controller 29 starts acceleration of the rotation speed based on the signal from the position detection circuit 31, and the electric motor 25 is changed from the current rotation speed (low speed rotation) to the target rotation speed. The controller 29 detects that the rotation speed detected based on the signal from the position detection circuit 31 has reached the target high-speed rotation at time tU4 and stops the acceleration of the rotation speed. To do.
[0062]
As a result, the target rotation is accelerated by accelerating the rotational speed of the electric motor 25 after the time tU2 when the voltage applied to the load power supply module 24 is boosted and reaches the double voltage, that is, while the voltage is constant. Control of the time to accelerate to speed is possible. Further, it is possible to prevent the rotation speed of the electric motor 25 from greatly exceeding the target rotation speed.
[0063]
As described above, the inverter device according to the present embodiment accelerates the rotational speed of the electric motor 25 while the applied voltage of the load power supply module 24 is constant, so that the resonance point inherent to the compressor is obtained. It is possible to control the timing of passing and the time taken to pass, and it is possible to realize rotational speed control that suppresses noise and noise to a minimum.
[0064]
In addition, regarding the operation of the electric motor 25 of the compressor constituting the refrigerator refrigeration system, the refrigerator user can have anxiety and distrust about whether the refrigerator is out of order by eliminating noise and noise. By preventing this, the reliability of the refrigerator can be improved.
[0065]
(Embodiment 3)
FIG. 4 is a timing chart showing the operation of the inverter device according to the third embodiment of the present invention.
[0066]
In the present embodiment, when the rotation speed of the electric motor 25 is further decreased, the voltage applied to the load power supply module 24 after the rotation speed of the electric motor 25 is decreased when the rotation speed of the electric motor 25 is decreased. Is provided.
[0067]
The operation of the inverter device configured as described above will be described below with reference to the timing chart of FIG.
[0068]
At time tD1, when the user has an opportunity to decelerate the speed of the electric motor 25 such as an energy saving command, the controller 29 starts decelerating the rotation speed based on the signal from the position detection circuit 31, and the electric motor 25 is rotated at the current speed. The controller 29 decelerates from the speed (high speed rotation) to the target rotation speed (low speed rotation), and the controller 29 indicates that the rotation speed detected based on the signal from the position detection circuit 31 has reached the target low speed rotation at time tD2. Is detected and the deceleration of the rotation speed is stopped.
[0069]
After stopping the deceleration of the rotational speed, the controller 29 gives a signal for turning off the relay 22b to the relay drive circuit 30 at time tD3. Then, the triac 22 a gives a phase control drive signal so as to repeat ON / OFF to the triac drive circuit 27, and starts to step down the voltage applied to the load power supply module 24. Then, the controller 29 detects that the applied voltage of the load power supply module 24 has reached all the voltages at the time tD4 from the signal output from the applied voltage detection circuit 28, and then completes the signal given to the switch means 22. To stop.
[0070]
Accordingly, the target rotational speed is reduced by reducing the rotational speed of the electric motor 25 before the time tD3 when the voltage applied to the load power supply module 24 is started, that is, while the voltage is constant. It is possible to control the acceleration time. Further, it is possible to prevent the rotation speed of the electric motor 25 from greatly lowering the target rotation speed.
[0071]
As described above, the inverter device according to the present embodiment is capable of refueling the electric motor 25 by reducing the rotation speed of the electric motor 25 while the applied voltage of the load power supply module 24 is constant. The rotational speed control that suppresses the wear of the electric motor to the minimum can be realized without falling below the lower limit value of the speed.
[0072]
Moreover, regarding the operation of the electric motor 25 of the compressor constituting the refrigerator refrigeration system, by suppressing excessive wear of the electric motor 25, the lifetime of the refrigerator can be secured for a longer period, and the reliability of the refrigerator can be improved.
[0073]
(Embodiment 4)
5 and 6 are timing charts showing the operation of the inverter device according to the fourth embodiment of the present invention.
[0074]
In the present embodiment, the inverter device according to any one of the first to third embodiments further has a function of more suitably performing the rotational speed control of the electric motor 25 when the applied voltage of the load power supply module 24 is transformed. It is provided.
[0075]
The operation of the inverter device configured as described above and the refrigerator including this device will be described below with reference to the timing chart of FIG.
[0076]
The controller 29 starts to accelerate the rotation speed based on the signal from the position detection circuit 31 at the time tP1 when the opportunity to accelerate the speed of the electric motor 25 such as the temperature in the refrigerator has increased. The controller 29 accelerates the electric motor 25 from the current rotation speed (low-speed rotation) to a rotation speed (intermediate speed) suitable for increasing the voltage applied to the load power supply module 24.
[0077]
Then, the controller 29 detects that the rotational speed detected based on the signal from the position detection circuit 31 has reached the intermediate speed at time tP2, and stops the acceleration of the rotational speed. After the acceleration of the rotational speed is stopped, at time tP3, the controller 29 gives a phase control drive signal to the TRIAC drive circuit 27 so that the TRIAC 22a repeats ON / OFF, and the voltage applied to the load power supply module 24 is increased. The controller 29 detects that the applied voltage of the load power supply module 24 has reached the double voltage at time tP4 based on a signal output from the applied voltage detection circuit 28, and the relay drive circuit 30 receives the relay 22b. Gives a signal to turn on.
[0078]
After the relay 22b is turned on, the controller 29 starts acceleration of the rotational speed based on the signal from the position detection circuit 31 at time tP5, and accelerates the electric motor 25 from the intermediate speed to the target rotational speed (high-speed rotation). The controller 29 detects that the rotational speed detected based on the signal from the position detection circuit 31 has reached the target high-speed rotation at time tU6, and stops the acceleration of the rotational speed.
[0079]
Accordingly, when the applied voltage of the load power supply module 24 is boosted, the applied voltage of the load power supply module 24 is changed by rotating the electric motor 25 at an intermediate speed that is a suitable rotation speed. Therefore, the rotation speed of the electric motor 25 is likely to fluctuate, but the rotation speed of the electric motor 25 is rotated by rotating the electric motor 25 sufficiently away from an inappropriate rotation speed such as a resonance point inherent in the compressor. In the unlikely event that fluctuates, rotation speed control that does not pass through the resonance point can be performed.
[0080]
As described above, when the inverter device according to the present embodiment transforms the applied voltage of the load power supply module 24, the motor 25 is rotated at an intermediate speed, which is a more preferable rotation speed. Rotational speed control that keeps the electric motor 25 in a better operating state can be realized.
[0081]
In the present embodiment, when an opportunity to accelerate the rotational speed of the electric motor 25 occurs, after the rotational speed of the electric motor 25 is accelerated to an intermediate speed, the applied voltage of the load power supply module 24 is boosted, and the electric motor The rotation speed of the motor 25 is accelerated to the target high-speed rotation. However, when the opportunity to reduce the rotation speed of the electric motor 25 occurs, the rotation speed of the electric motor 25 is reduced to an intermediate speed as shown in FIG. Thereafter, the voltage applied to the load power supply module 24 may be reduced, and the rotation speed of the electric motor 25 may be reduced to the target low-speed rotation.
[0082]
As a result, even if the rotation speed of the electric motor 25 fluctuates while the applied voltage of the load power supply module 24 is being lowered, the rotation speed at which refueling cannot be achieved does not occur, and a better operating state is maintained. Such rotational speed control can be realized.
[0083]
Moreover, regarding the operation of the electric motor 25 of the compressor constituting the refrigerator refrigeration system, by suppressing excessive wear of the electric motor 25, the lifetime of the refrigerator can be secured for a longer period, and the reliability of the refrigerator can be improved.
[0084]
【The invention's effect】
As described above, according to the first aspect of the present invention, the in-voltage of the power supply module for load is transformed slowly by the non-contact switch means, and the mechanical switch with relatively small power loss at the time of double voltage. By switching to the means, it is possible to reduce the size of the switch means, and it is relatively small by performing transformation while rotating the electric motor at a rotation speed that can be realized even after the applied voltage of the load power supply module is transformed. With respect to voltage fluctuations and load fluctuations, the rotational speed of the electric motor does not become unstable, and rotational speed control that does not generate abnormal noise and noise is possible.
[0085]
According to the second aspect of the present invention, when the applied voltage of the load power supply module is transformed, it is transformed with the non-contact switch means and is switched to the mechanical switch means with relatively small power loss when the voltage is doubled. Thus, the switch means can be miniaturized, and the rotational speed of the motor can be accelerated while the applied voltage of the load power supply module is constant, which can greatly exceed the target rotational speed (high-speed rotation). In addition, it becomes possible to control the time when the compressor passes through the resonance point inherent in the compressor and the time required for the compressor to pass, and it is possible to control the rotational speed so as to minimize noise and noise. .
[0086]
According to the third aspect of the present invention, when the applied voltage of the load power supply module is transformed, it is transformed with the non-contact switch means and is switched to the mechanical switch means with relatively small power loss when the voltage is doubled. Thus, the switch means can be miniaturized, and the motor rotation speed can be greatly reduced below the target rotation speed (low-speed rotation) by reducing the rotation speed of the motor while the applied voltage of the load power supply module is constant. The rotation speed can be controlled so as not to fall below the lower limit value of the rotation speed at which the oil can be supplied to the motor, and the rotation speed can be controlled to minimize the wear of the motor.
[0087]
According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, when the rotational speed of the electric motor is changed, the voltage applied to the load power supply module is more varied. After changing the rotation speed of the motor to a suitable intermediate speed, the applied voltage is transformed, and after the transformation is completed, the speed of the motor passes through the resonance point by shifting to the target rotation speed, Phenomena such as a rotational speed at which refueling to the electric motor is impossible are eliminated, and rotational speed control that keeps the electric motor in a better operating state becomes possible.
[0088]
Invention of Claim 5 is a refrigerator using the inverter apparatus as described in any one of Claims 1-4, If it is a refrigerator using the invention of Claim 1 and Claim 2, By preventing abnormal noise and noise related to the operation of the compressor motors that make up the refrigeration system, it is possible to prevent the refrigerator users from having anxiety and distrust about whether the refrigerator is malfunctioning. , Can improve the reliability of the refrigerator. Moreover, if it is a refrigerator using the invention of Claim 3 and Claim 4, the excessive wear of the electric motor of a compressor can be suppressed, a long-term lifetime can be ensured, and the reliability of a refrigerator can be improved.
[Brief description of the drawings]
FIG. 1 is a block diagram of a first embodiment of an inverter device according to the present invention.
FIG. 2 is a timing chart of the first embodiment of the inverter device according to the present invention.
FIG. 3 is a timing chart of Embodiment 2 of an inverter device according to the present invention.
FIG. 4 is a timing chart of Embodiment 3 of an inverter device according to the present invention.
FIG. 5 is a timing chart of Embodiment 4 of an inverter device according to the present invention.
FIG. 6 is a timing chart of Embodiment 4 of an inverter device according to the present invention.
FIG. 7 is a block diagram of a conventional inverter device.
[Explanation of symbols]
21 Rectifier circuit
22 Switch means
22a Triac (Solid state switch means)
22b Relay (Mechanical switch means)
23 Smoothing circuit
24 Power supply module for load
25 Electric motor
26 Zero cross detection circuit
27 Triac drive circuit
28 Applied voltage detection circuit
29 Controller
30 Relay drive circuit
31 Position detection circuit

Claims (5)

A rectification / smoothing circuit that converts constant-voltage input AC power to DC power;
A load power supply module that converts the DC power converted by the rectification / smoothing circuit into required power and supplies it to a load such as a compressor motor;
Driving means for driving the load power supply module;
A position detection circuit for detecting the rotational speed of the electric motor;
Mechanical switch means for switching the rectification / smoothing circuit between a full-wave rectification circuit and a voltage doubler rectification circuit;
Contactless switch means for gently changing the voltage applied to the load power supply module when the mechanical switch means switches the rectifying and smoothing circuit;
In an inverter device having a controller for commanding transformation of applied voltage to the load power supply module, speed change of the electric motor, etc.
When changing the voltage applied to the power supply module for load in the range of full-wave rectification to voltage doubler rectification as the rotational speed of the motor is changed, either before or after changing the voltage The inverter commands the load power supply module so that the rotation speed is operable even with an applied voltage, and changes the voltage while operating the motor at the rotation speed. . A rectification / smoothing circuit that converts constant-voltage input AC power to DC power;
A load power supply module that converts the DC power converted by the rectification / smoothing circuit into required power and supplies it to a load such as a compressor motor;
Driving means for driving the load power supply module;
A position detection circuit for detecting the rotational speed of the electric motor;
Mechanical switch means for switching the rectification / smoothing circuit between a full-wave rectification circuit and a voltage doubler rectification circuit;
Contactless switch means for gently changing the voltage applied to the load power supply module when the mechanical switch means switches the rectifying and smoothing circuit;
In an inverter device having a controller for commanding transformation of applied voltage to the load power supply module, speed change of the electric motor, etc.
When the voltage applied to the load power supply module is boosted in the range of full-wave rectification to voltage doubler rectification as the motor is rotated at a higher speed, the controller commands the load power supply module, An inverter device characterized in that the motor is shifted while the applied voltage is constant, and the applied voltage is boosted while the rotational speed of the motor is constant. A rectification / smoothing circuit that converts constant-voltage input AC power to DC power;
A load power supply module that converts the DC power converted by the rectification / smoothing circuit into required power and supplies it to a load such as a compressor motor;
Driving means for driving the load power supply module;
A position detection circuit for detecting the rotational speed of the electric motor;
Mechanical switch means for switching the rectification / smoothing circuit between a full-wave rectification circuit and a voltage doubler rectification circuit;
Contactless switch means for gently changing the voltage applied to the load power supply module when the mechanical switch means switches the rectifying and smoothing circuit;
In an inverter device having a controller for commanding transformation of applied voltage to the load power supply module, speed change of the electric motor, etc.
As the electric motor is rotated at a lower speed, the controller commands the load power supply module when the voltage applied to the load power supply module is stepped down in the range of full-wave rectification to voltage doubler rectification, An inverter device characterized in that the electric motor is shifted while the applied voltage is constant, and the applied voltage is lowered while the rotational speed of the electric motor is constant. When the voltage applied to the load power module is changed as the rotation speed of the motor is changed, the controller supplies the load power so that the intermediate speed is a more preferable rotation speed at the time of transformation. 4. The inverter device according to claim 1, wherein a command is given to the module, the rotation speed of the electric motor is changed to the intermediate speed, and the voltage is transformed after reaching the intermediate speed. 5. . The refrigerator having an inverter device according to any one of claims 1 to 4, further comprising: a compressor constituting a refrigeration system, wherein the inverter device drives an electric motor of the compressor.

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