JPS6130519B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a high-efficiency air conditioner that can perform energy-saving operation with a large effective energy ratio (EER) in both 50Hz and 60Hz regions, and furthermore, in the case of light load operation. Similarly, EER
It was designed so that it could be raised.

When the compressor, which consumes the largest amount of power in an air conditioner, is driven by an AC induction motor, the characteristics of the induction motor are more affected by reactance than resistance, so it is not suitable for use in the 50Hz region.
There is a 20% frequency difference in the 60Hz region, which has a large effect on the characteristics of the electric motor.

If you design a motor for both 50Hz and 60Hz from this point of view, the maximum efficiency will not be achieved in both cases, with a leading power factor in the case of 60Hz and a lagging power factor in the case of 50Hz.

By the way, if you design it to be most efficient at both 50Hz and 60Hz, in the case of a single-phase induction motor, the number of main windings will be larger at 50Hz, which has a lower rotation speed. In capacitor-operated single-phase induction motors, which are generally used in small air conditioners, a highly efficient motor can be achieved by having more windings in the auxiliary winding, which is in series with the capacitor, than in the main winding. It is known.

From the above, at 50Hz, especially in the case of a capacitor-operated single-phase induction motor, switching the auxiliary winding to the main winding and the main winding to the auxiliary winding will reduce the turns ratio of both windings. By making a proper selection, it is possible to obtain a motor that can operate with high efficiency at both 50Hz and 60Hz, and after conducting various experiments, the results of the motor efficiency relative to the output are shown in Figure 4. It's obvious from the outside.

In this case, the maximum output of the motor is lower at 50Hz than at 60Hz, but because the rotation speed is lower, the load on the air conditioner is lighter at 50Hz than at 60Hz, as shown in the characteristics in Figure 4. As shown, it has ideal characteristics of high efficiency under light loads.

Therefore, at 50 Hz and 60 Hz, the main winding and auxiliary winding are used separately to operate the motor, and the capacitor-operated single-phase capacitor-operated type enables switching while maintaining such high efficiency. Some air conditioners have been proposed in which an induction motor is connected to a compressor.

However, the actual situation is that the following problems have not yet been solved and are hindering their practical application.

In other words, the wiring of a general-purpose capacitor-operated single-phase induction motor (hereinafter abbreviated as a capacitor motor) is of a three-terminal type, with one terminal coming out of the first winding, which becomes the main winding, and one terminal, which becomes the auxiliary winding. It consists of a terminal coming out of the second winding, the opposite winding ends of both the first and second windings, and a common terminal coming out from this.

If you replace the first and second windings by connecting the capacitor to the first winding terminal and directly connecting the second winding terminal to the power supply using the above connection,
Capacitor motors cannot be used in rotary compressors because they rotate in reverse.

Therefore, it is naturally necessary to reverse the direction of the current flowing into one winding at the same time as changing the connections.

In this way, when the polarity of one winding is changed, the magnetic poles of the rotor core magnetized by the rotating magnetic field before switching and the magnetic poles of the rotating magnetic field after switching change in electrical angle.
Since a phase difference of 90 degrees is generated, immediately after switching, a pulling force is generated in the direction of rotation or a force pulling back in the opposite direction of rotation, depending on the switching direction.

For example, in connection A in Figure 2, the first winding 2
When a current i _M is passed through the second winding 3 which is connected in series with the capacitor, then _{i M} ×
The combination of the magnetic field generated by W ₁ and the magnetic field generated by i _A × W ₂ becomes a rotating magnetic field, and from the moment i _M is 0, the time of one cycle is divided into 8 equal parts, and each elapsed time, ,
The direction of the polarity of the composite magnetic field of ... is as shown by the array A in the middle row of FIG.

After switching the wiring connections from this state as shown in (b), the rotating magnetic field also becomes as shown in the arrangement (b) in the lower part of FIG.

As can be seen from Figure 2, in this example, both in case of result A and in case of connection B, the rotation direction of the rotating magnetic field is the same as the clockwise direction, but there is a difference of 90 degrees in electrical angle.
This angle difference poses a problem when switching.

For example, if the current flows over time in Figure 2, and the connection is switched from A to B, the stator 5 side will have a A N pole is formed on the left side and an S pole is formed on the left side, and due to the horizontal magnetic field in this figure, the rotor 4 has an N pole on the left side and an S pole on the right side. When switched, stator 5
The upper side magnetic pole is the S pole, and the lower side is the N pole, forming a vertical magnetic field.

At the moment of this switching, the rotor 4 remains as a magnetized pole in the A state (due to residual magnetism), so the rotor 4 is pulled in the direction of rotation and a force in the direction of acceleration is applied.

On the other hand, if you switch the connection from A to A, the situation will change from B to A in [ ] in Figure 3, and at that moment, a pullback force will be applied in the opposite direction to the rotation direction, and the rotary compression will change. In the case of aircraft, a force that has a particularly negative effect is added.

In addition, if the connection at the elapsed time in Figure 2 is switched from A to B, or vice versa, it will not be pulled in the rotational direction or in the opposite direction, as illustrated in ``'' in Figure 3. It is clear that a returning force is applied.

Because of the above-mentioned phenomenon, if the capacitor motor is operated instantaneously by following load fluctuations between normal operation and load operation, a mechanical shock will occur due to the transient phenomenon, and the internal and rotating parts of the compressor will be damaged. Not only does it have various negative effects on the shaft,
The current increases transiently, which has a considerable effect on the wiring system, and it has not been widely used because it poses major practical problems.

In order to deal with this fact, the present invention changes the connection of both the first and second windings, and cuts off the power supply to the capacitor motor for a short period of time when switching the operation while maintaining high efficiency so as not to stop the motor. At the same time, by changing the connection so that the direction of current flowing through one winding is reversed, the occurrence of the above-mentioned transient phenomenon can be prevented and the mechanical shock can be alleviated. be.

Therefore, the present invention is particularly advantageous in that the stator has a first winding and a second winding having a larger number of windings than the first winding, and the operating capacitor is connected to the first winding when operating at 50 Hz or below or under light load at 60 Hz. The capacitor motor is connected in series to the compressor, and is connected in series to the second winding during normal load operation below 0 Hz, enabling switching operation that maintains high efficiency. The electrical circuit controlling the operation capacitor is connected in series to the first winding for operation under 50 Hz and light load operation under 60 Hz, and connected in series to the second winding for normal load operation under 60 Hz. a changeover switch mechanism that performs parallel connection change in which the polarity is changed between the two windings at the same time as the changeover;
a switch mechanism for applying power supply voltage to the induction motor and the operating capacitor; and a switch mechanism that operates in conjunction with the changeover switch mechanism when switching between normal load operation and light load operation at 60 Hz;
The present invention is characterized in that it includes a timer that disables the switch mechanism for the time required for the residual air of rotation to attenuate.

Hereinafter, specific contents of the present invention will be explained in detail with reference to the additional drawings.

FIG. 1 is an electric circuit diagram of an outdoor unit related to the air conditioner of the present invention, in which a capacitor motor 1 connected to a compressor (not shown) has a first winding 2 and a first winding 2.
The stator 5 has a second winding 3, which has a larger number of turns than the winding 2, and the capacitor group consisting of the operation capacitors 6a and 6b is connected to the first winding when operating at 50 Hz or below 60 Hz with a light load. By connecting it in series to the wire 2 and connecting it in series to the second winding 3 during normal load operation under 60 Hz, switching operation that maintains high efficiency can be performed.

The main function of the electric circuit described above is to switch and connect the capacitor group, and 7 is an electromagnetic contactor whose elements are contacts 7a to 7c and a coil 7d. It is operated by the operation control current from the indoor unit applied to terminal 4, and the capacitor motor 1 and fan motor 8
It is designed to apply voltage to the

9 are normally open contacts 9a to 9c, normally closed contacts 9d to 9e
and a relay including a coil 9f as an element,
Switching signal from indoor unit to 50Hz operation and 60
It is activated when a switching signal for light load operation under Hz operation is applied to terminal 3.

A relay 10 includes a normally open contact 10a and a coil 10b, and is activated when the relay 9 is activated and a timer 14, which will be described later, measures a set time, and activates the electromagnetic contactor 7. .

Reference numeral 11 denotes a relay that includes a normally open contact 11a and a coil 11b, and is activated when the relay 9 is inactive and a timer 15, which will be described later, has timed a set time, and activates the electromagnetic contactor 7. urge

12 is a relay whose elements are a normally closed contact 12a and a coil 12b, and when the load becomes light after switching to 50Hz operation, when a control signal from the indoor unit is applied to terminal 2, it is activated to disconnect the operating capacitor 6b. Operate.

13 are switching contacts 13a to 13c, coil 13d
This relay is operated when a timer 16, which will be described later, measures a set time, and brings the capacitor mode band 1 into contact with the winding, which is highly efficient at 50 Hz.

14 is a time-limited normally open contact 14a and a drive unit 14b
This is a timer that operates the electromagnetic contactor 7 several seconds after the switching signal between 50Hz operation and light load operation under 60Hz operation is input, and instantly deactivates the contactor 7 by resetting the timer. and
When the capacitor motor 1 is operating under normal load operation at 60 Hz and is stopped due to emergency energization, a period corresponding to the time required for the residual magnetism of the rotor 4 to decrease is set.

15 is a time-limited normally open contact 15a and a drive unit 15b
This is a timer with an element of
On the other hand, the contact 7 is instantly deactivated by resetting, and when the capacitor motor 1 is running at 50 Hz and is de-energized, the residual magnetism of the rotor 4 is removed. It has a set time corresponding to the time until it decays.

16 is a timer whose elements are time-limited normally open contacts 16a, 16b and a drive section 16c;
The relay 13 is actuated by the contact 16a, which operates faster than the set time elapses after the timer 4 starts counting, to change the connection of the capacitor motor 1 from 60 Hz operation to 50 Hz operation.

Reference numeral 17 functions as a timing relay for maintaining the operation of the relay 13, which includes a normally open contact 17a for instantaneous closing return and a driving portion 17b.

Although each component has been explained above,
In this circuit example, the mechanism that issues control commands is installed in the indoor unit, but a 50Hz/60Hz selector switch is attached to the outdoor unit to detect the outdoor temperature or the pressure and temperature in the refrigerant system. The same function can be obtained even if only the outdoor unit is equipped with a mechanism that issues a control command to detect the load condition and operate the outdoor unit.

If we outline the mode of air conditioning operation based on the above circuit, when the operation switch (not shown) is turned on, if the frequency is 60Hz and the load is high, relay 9 is turned off, relay 12 is also turned off, and the power is turned off. Since the timer 15 has been installed for a while, the timer 15 is already operating, so the relay 11 is turned on and the electromagnetic contactor 7 is activated, and as shown in the first figure, the first winding 2 is the main winding and the The second winding 3 becomes the auxiliary winding, and the capacitor immediately starts operating with both 6a and 6b functioning as phase advancers.

Next, when the air conditioning load decreases and a switching signal to the light negative liquid is input, the relay 9 is turned on, the timer 14 is energized, and at the same time the relay 11 is turned off, the magnetic contactor 7 is deactivated, and the capacitor motor 1 is turned off. Power supply will be cut off immediately.

Then, as a result of the relay 13 being turned on after a very short delay due to the operation of the timer 16, the windings of the capacitor motor 1 are reconnected, so the windings are connected only after the electromagnetic contactor 7 is in a non-operating state. A replacement will take place.

This winding connection is changed by switching contacts 13a to 13c, so that the first winding 2 becomes the auxiliary winding connected in series with the capacitors 6a and 6b, and the second winding 3 becomes the main winding that receives direct power supply from the power supply. The polarity of the second winding 3 is changed relative to the first winding 2 so that the direction of current flowing through the second winding 3 is reversed. This is done with the aim of creating connections that can create parallel relationships that convert.

However, after the timer 16 is activated, the timer 1
4 emits an output after the set time elapses,
Relay 10 is turned on, and electromagnetic contactor 7 is activated.

In this way, by increasing the number of windings by using the second winding 3 as the main winding, and conversely reducing the number of windings by using the first winding 2 as the auxiliary winding, Since the maximum output of 1 is reduced and the highest point of efficiency is moved to the light load side (see Figure 5), operation with high EER is possible even during light load operation.

It should be noted that when the electromagnetic contactor 7 is inactive for a short period of time and the power supply to the capacitor motor 1 is cut off, for example 2 to 3 seconds, the residual magnetism in the rotor 4 almost disappears, and the When the power is re-supplied, there is no influence of residual magnetism, and smooth switching operation is possible.

On the other hand, when returning from 60Hz light load operation to normal load operation, relay 9 is turned off by the control signal, timer 14 is immediately turned off, and relay 1
0 is also turned off, and thus the electromagnetic contactor 7 is also deactivated.

At this time, the timer 16 is also turned off, but since the timer 17 is a timed return timer, the relay 13 is turned off by the opening of the contact 17a, which operates with a slight delay, and therefore the electromagnetic contactor 7 is completely deactivated. After that, the relay 13 is turned off and the winding of the capacitor motor 1 is switched to the high load side.

On the other hand, the timer 15, which had started timing immediately when the relay 9 was turned off, is activated after the set time has elapsed, so that the relay 11 is turned on and the electromagnetic contactor 7 is activated.

At this time, the windings of the stator 5 have been reconnected to the state shown in Figure 1, and the residual magnetism of the rotor 4 has almost disappeared, so the transition to the high load side is smooth. Switching operation becomes possible.

Please note that if you switch between 60Hz and 50Hz when you install the air conditioner, you will not need to change it afterwards unless you move to an area with a different power supply frequency, so use a manual switch to switch between 60Hz and 50Hz, and if you use it in a 50Hz area, please use a light load. The signal is also switched so that it is applied to the third terminal and the second terminal of the terminal board T.

By doing so, when a light load signal is input, the relay 12 is turned on and the capacitor 6b is disconnected from the circuit, resulting in switching to small capacity operation.

Next, the effects of the present invention are as shown in the following sections.

(b) By switching the connection between the first winding 2 and the second winding 3, it is possible to operate with high efficiency depending on the air conditioning load, allowing operation with high EER in both 50Hz and 60Hz regions, resulting in energy savings. It is a great place to contribute to.

(b) In any operation, since there is no idle part of the stator winding that is disconnected from the power supply, the capacitor motor 1 can be made smaller and easier to manufacture compared to the conventional system in which an intermediate tap is provided for switching. .

(c) Since the mechanical shock caused by the transient phenomenon at the time of switching is alleviated, the mechanical life of the condenser motor 1 and the compressor is extended, and a highly reliable air conditioner can be provided.

[Brief explanation of the drawing]

Each figure shows the aspect of an example of the air conditioner of the present invention. Figure 1 is an electric circuit diagram related to the outdoor unit, and Figure 2 is a rotating magnetic field when changing the winding connection of a capacitor motor for a compressor. Fig. 3 is an explanatory diagram showing the changing state, and Fig. 3 is an explanatory diagram showing the direction of magnetization in the rotor and the direction of the attractive force during transition, respectively.
Figure 5 is a diagram comparing the efficiency change when changing the winding connection of a capacitor motor between Hz and 60Hz.
Figure 6 is a diagram comparing efficiency changes when winding connections are changed in Hz operation, and Figure 6 is a diagram comparing efficiency changes when changing capacitor capacity in 50Hz operation. 1...Capacitor operation type single phase induction motor, 2...
...First winding, 3...Second winding.

Claims (1)

[Claims] 1 The stator has a first winding 2 and a second winding 3 having a larger number of windings than the first winding 2, and the operating capacitor 6a is operated under 50 Hz and under light load at 60 Hz. The following describes a capacitor-operated single-phase induction motion machine 1 that enables switching operation while maintaining high efficiency by connecting the first winding 2 in series and the second winding 3 during normal load operation at 60 Hz. is connected to the compressor, and an electric circuit for controlling the operation of the single-phase induction motor 1 is provided, and in the electric circuit, an operating capacitor 6a is connected to the first volume for operation under 50 Hz and light load operation under 60 Hz. Wire connection change in which the line is connected in series to the wire 2 and connected in series to the second winding 3 during normal load operation under 60 Hz, and parallel connection change in which the polarity is switched between the two windings 2 and 3 at the same time as the connection change. a switch mechanism for applying power supply voltage to the induction motor 1 and the operating capacitor 6a, and a switch mechanism that operates in conjunction with the changeover switch mechanism when switching between normal load operation and light load operation at 60 Hz. and a timer for inactivating the switch mechanism for the time required for the residual magnetism of one rotor of the motor to decay.