JPS62281726A - Reverse phase protector of freezer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention (Field of Industrial Application) The present invention detects misconnection of the three-phase power supply to the compressor when operating the compressor built in the refrigeration unit. This invention relates to an improvement in a reverse phase protection device for a refrigeration system that prevents reverse rotation of a compressor.

(Prior Art) Conventionally, as a reverse phase protection device for this type of refrigerator, for example, as disclosed in Japanese Utility Model Publication No. 58-32456,
A device using a reverse phase detection relay is known. As shown in FIG.
Connect the terminals (R), (S), and (T> to each other in a star shape, and connect the reverse phase detection relay (b) that acts as the induction/chillactance to the R phase of this star connection, for example, to detect the positive A capacitive reactance (C) is connected to the phase, and a resistance (d) is connected to the S phase. The drive magnetic contact is interposed in the power supply circuit of the transmitter (e) to ensure that the three-phase power supply is normal (positive phase).
In the case of wiring, the voltage applied to the reverse detection relay (b) is high and its r#J contact (b-+> is normally closed, causing the power supply circuit of the magnetic contactor (e) to close. While this configuration allows forward rotation of the compressor (a), when the three-phase power supply is connected in reverse phase, the voltage applied to the reverse phase detection relay <b> decreases, and therefore its normally open contact (b +) There is known a device in which the power supply circuit of the electromagnetic contactor (e) is opened, thereby preventing the power supply from the three-phase power supply and thereby preventing the compressor 1(a) from rotating in the opposite direction.

(Problem to be solved by the invention) However, in the above-mentioned conventional device, the negative phase detection relay (
1)), the normally open contact (b
-+) As the opening/closing operation is repeated, the R performance deteriorates over time, and there is a drawback that the reliability and durability of reverse phase detection cannot be ensured as high as expected.

In view of these points, the present invention adopts a non-contact method,
This was done by focusing on the special phase difference of three-phase alternating current. That is, the 120'' phase difference relationship between each phase of the three-phase AC is the same for the potential difference waveform between each phase,
A predetermined phase (for example, S phase) of these three types of potential difference waveforms
There is a phase difference of 1200 between the two types of potential difference waveforms based on , so if one of them is used as the reference waveform, the other will be a predetermined lead or lag waveform, whereas
When connecting in reverse phase (mistake), the lead relative to the above reference waveform,
The aim is to detect the leading and lagging phase relationship with respect to the reference waveform, thereby eliminating the need for a conventional negative phase detection relay, and to provide non-contact type negative phase protection. It is an object of the present invention to provide a device and to maintain its reliability and durability at a high level at all times by preventing deterioration of its reliability and durability as much as possible over time.

(Means for Solving the Problems)) In order to achieve the above object, the solution of the present invention is that the connection of the three-phase power supply (2) to the compressor (1) is A reverse phase protection device for the refrigerating tank is designed to detect incorrect wiring connected to a phase opposite to the phase order that matches the rotation direction of the WJ machine (1) and prevent the compressor (1) from rotating in reverse. Assumed. and a first waveform creation means (13) that creates a waveform according to a potential difference between a predetermined reference phase and another phase of the three-phase voltage applied to the compressor (1);
A second waveform creation means (16) is provided for creating a waveform according to the potential difference between the basic Iv phase and the remaining one phase. Furthermore, a phase difference relationship detection means (2Q) for detecting a phase difference relationship between the waveforms of the second waveform creation means (16) using the waveform of the first waveform creation means (13) as a reference waveform; An operation inhibiting means (21) is provided for prohibiting the operation of the N machine (1) at the above pressure when the phase difference relationship detected by the detection means (20) is different from the phase difference relationship at the time of normal phase. be.

(Function) With the above configuration, in the present invention, when the three-phase power supply (2) is normally connected to the positive phase, the second waveform creation means (16) is Since the phase of the waveform is not reversed in the phase difference relationship detection means (20) and has the same leading or falling phase relationship as in the positive phase, the operation inhibiting means (21) does not operate and the compressor (1) It can be rotated in the forward direction.

On the other hand, when the three-phase power supply (2) is connected to the opposite phase, the base Q waveform of the first waveform creation means (7, 3>) and the comparison waveform of the second waveform creation means (16) are swapped. For this reason, the phase difference relationship between the comparison waveform and the reference waveform is reversed from that in the normal phase, so the operation!7I inhibiting means (21) is activated and the reverse operation of the compressor (1) is prohibited. That will happen.

(Example) Hereinafter, an example of the present invention will be described based on the drawings from FIG. 2 onwards.

In Fig. 2, (1) is a compressor, and (2) is a three-phase power supply that supplies three-phase alternating current of R phase, S phase, and positive phase as shown in Fig. 6 (a), and the three-phase power supply (2) R$0. S+t1 and the positive phase are connected to the pressure N machine (1) by connection wiring (3) to (5), respectively.
), a power supply circuit (7) is formed by connecting the wires in correspondence with the R terminal, S terminal, and T terminal of the power supply terminal (6), thereby connecting the three-phase power supply (2) to the compressor (1). supplying a current with the phase rotation direction being R → the positive phase direction of the 5-JT phase,
The pressure is 1 m (1) and it is rotated in the forward direction.

Further, (A) is a negative phase protection device that detects a misconnection (that is, negative phase connection) of the three-phase power supply 2 to the compressor (1), and the negative phase protection device (A) It is connected to the R terminal, S terminal, and T terminal of the power terminal (6) of 1), and is capable of detecting the phase rotation direction of the three-phase voltage supplied to the compressor (1).

Next, the internal structure of the above-mentioned reverse phase protection device @(A) is shown in FIG. In the figure, (10) is an IC circuit, and (52C) is an electric vIi contactor having a normally open contact (52C-+) interposed in the middle of the power supply circuit (7) to the compressor (1). Then, the electromagnetic contactor (52C) + 7) OFFflEtll
l[]t, the power supply circuit (7) of the compressor (1) is opened by opening the sono normally open mQ (52'C-+), and the compressor (1)
) to prevent rotation.

Furthermore, a control relay (23A) having a normally open contact (23A-+) is connected to the output side of the IC circuit (10), which is connected to the power supply circuit of the electromagnetic contactor (52G). Then, the electromagnetic contactor (
52C) ON -OF F 1li (11 by I command)
It is designed to perform activation/stop control of the dilation vM(1).

Furthermore, (11) is a rectifier diode that half-wave rectifies the secondary voltage of the transformer (12) connected to the R phase and S phase of the three-phase power supply (2), and (Tr) is the rectifier diode (11).
The transistor (Tr) is turned on in response to a half-wave rectified voltage signal, and the collector potential of the transistor (Tr) is used as an interrupt signal as shown in FIG. 6 (b) in the above IC circuit (
10) Enter the tag. As a result of the above, the compressor (1
), depending on the potential difference between a predetermined reference phase (S phase) and another set (R phase) of the three-phase power supply (2) applied to
Waveforms corresponding to the positive and negative (signal including gear 1 in Figure 6 (b))
It constitutes a first waveform creation means (13) that creates a waveform.

Furthermore, in FIG. 3, (15) is the compressor (1).
is a photocoupler connected to the T phase and S phase of the power supply terminal (7), and the light emitting diode (15a) of the photocoupler (15) connects the S phase to the T phase of the three phase power supply (2). connected to allow current F to pass, and
The ON-OFF signal of the phototransistor (15b) is input to the IC circuit (10). Therefore, the photocoupler (15) detects the standard phase (S) of the three-phase AC.
A second waveform creation means (16) configured to create a waveform shown in FIG. 6 (c) corresponding to the positive or negative of the potential difference, depending on the potential difference between the phase (T phase) and the remaining one phase (T phase). It consists of Here, the waveform of FIG. 6 (b) created by the first waveform creation means (13) and the second waveform creation means (16)
The waveform of FIG. 6(C) created in FIG.
The relationship has a phase difference of 20°, as shown in the same figure (b).
When the waveform shown in the figure (c) is used as the reference waveform, the waveform shown in the figure (c) is delayed by 120 degrees, and when the waveform shown in the figure (b) rises, the waveform shown in the figure (c) is delayed by 120 degrees. In other words, the photocoupler (15) is in the ON state. On the other hand, when the three-phase power supply (2) is incorrectly connected, for example, when the R phase and T phase are connected in reverse phase, the position of the three-phase AC at the applied hO voltage of the compressor (1) As the phase difference relationship is reversed, the output signal of the transistor (Tr) becomes g15.
As the waveform becomes as shown in Figure 7 (b), the photocoupler (15)
(7) ON-OF F state 1fi The waveform in the figure (A) will be reversed, so if the waveform in the figure (B) is used as the reference waveform, the waveform in the figure (C) will be 120 The waveform becomes a leading waveform of °, and at the rise of the waveform shown in the same figure (b), the waveform shown in the same figure (b) becomes
The waveform of c) is in the H state, that is, the O of the photocoupler (15).
It will be in the FF state.

In addition, a negative phase display diode (LED) is connected to the output side of the above IC circuit (10), and in the event of a misconnection,
This negative phase display diode (LED) is turned on to remind the user to reconnect the three-phase power supply (2) in response to a misconnection.

Next, the operation of the IC circuit (10) will be explained based on the flowcharts of FIGS. 4 and 5. Zu-Narichi, @4
Starting from the main flow in the figure, various values are initialized in step SMI, and then, in step SM2, for example, in order to converge the temperature in the air-conditioned dormitory to the set value (target value),
Pressure W1 machine (1) according to bliss 1lill
12[].

If the waveform signal shown in FIG. 6 (b) or FIG. 7 (b) from the transistor (TM) is input while the main flow is in progress, this main flow is interrupted and Proceed to interrupt flow.

Next, to explain the flow in Figure 5, in step S1 it is determined whether the photocoupler (15) is in ON operation or not, and when the three-phase power supply (2) is normal and there is no misconnection, as shown in Figure 6. As can be seen from (c), it is in the ON state, so step S
2, and in step $2 it is further determined whether or not it was in the ON state last time, and if NO because it was not in the ON state last time, step S is performed in order to prevent malfunction due to noise.
Step 3 resets the number of detections N to the initial value "O" and returns, while if the answer is YES as it was in the ON state last time, add "1" to the number of detections N in step S1, and then
Furthermore, in step S5, it is determined whether or not the number of detections N is equal to a predetermined number m (for example, 16), and in the case of No of N m, it is determined that it is too early to make the determination and returns immediately, while N=m If it is possible to accurately determine YES, in step S6 the number of detections N is reset to rOJ, and in step S7 it is determined that the phase is normal, and in step S8 the control relay (23A> is turned ON). Then, the pressure M1 (1) is rotated in the normal direction, the reverse phase display diode LED is turned off, and the process returns.

On the other hand, in step S2 above, the photo cover 15) is OF
In the case of No in the F state, that is, in the case where there is a possibility of incorrect connection, it is further determined in step S whether or not it was in the OFF state last time, and in the case of No that it was in the ON state last time, In order to prevent malfunctions due to noise, the number of detections N is reset to the initial value "O" in step S3 and the process returns.If YES, as it was in the OFF state last time, the detection port is turned off in step S IQ. After adding "1" to VIN, further step S u determines whether the number of detections N is equal to a predetermined number m (C, for example, 16) by 11, and N
If <m is NO, it is determined that it is too early to make the determination and returns immediately, but if N=m is YES, when accurate determination is possible, the number of detections N is determined in step 312.
After resetting to the initial value "0", step S L3
It is determined that the phase is reversed, and at step S L4, the control relay (23A) is turned OFF to prohibit rotation of the compression oyster (1), and the reverse phase display diode LED is turned off.
Light up and return.

Therefore, in step 6 of the interrupt flow shown in FIG.
Based on the rising time of the output waveform shown in FIG. 6 (B) or FIG.
Using the waveform created by the reference waveform, the operating state of the photocoupler (15) shown in FIG. 6 (c) or FIG. 7 (c) (that is, the waveform created by the second waveform creation means (16)) The phase difference relationship detecting means (20) is used to detect the phase difference relationship (phase difference relationship). Also, step 81+-81
4, the operation of the compression reform (1) is prohibited when the phase difference relationship detected by the phase difference relationship detection means (20) is an advanced phase that is different from the phase difference relationship (lag phase) in the case of a positive phase. The operation inhibiting means (constituting 21).

Therefore, in the above embodiment, when the three-phase power supply (2) is connected normally (positive phase), the sixth waveform is figure(
Since the phase difference relationship of the waveform created by the second waveform creation means (16) in c) has the same sucking phase as the three-phase AC waveform in FIG. do not. As a result, the control relay (23A) # and the magnetic contactor (52
C) turns ON as usual, and P: Condensation (1) normally rotates in the normal direction.

On the other hand, when the three-phase power supply (2) is connected to the opposite phase and the wrong connection is made, the first waveform creation means (13) shown in Fig. 7 (b)
The phase difference relationship between the waveform created by the second waveform creation means (16) in FIG. 7(C) with respect to the reference waveform created in
The leading phase is different from the above-mentioned delayed phase, and as a result, the actuation inhibiting means (21) is actuated, and the control relay (2
3A) and the magnetic contactor (52C) are held in the OFF state, so the pressure! 1 (1) is reliably prevented, and the reverse phase indicator diode (LED) lights up to indicate incorrect connection of the three-phase power supply (2), so the compressor (
The cause of 1) inoperability can be easily understood.

Here, detection of reverse phase connection of the three-phase power supply (2) is as follows:
Since it is a non-contact type that uses a photocoupler (15), it minimizes deterioration in reliability and durability over time compared to a contact type that uses a conventional glue-based negative phase detection relay. Therefore, this can be maintained at a high level at all times.

In addition, FIGS. 8 to 10 show the phase difference relationship detection means (2
0) and the operation inhibiting means (21). In the above embodiment, the phase difference relationship is detected by grasping the operating state of the photocoupler (15) at the rising edge of the output signal of the transistor (Tr). In addition, there is a region of 120 to 1800 in which the phase difference relationship is reversed between normal phase connection and reverse phase connection (shown by bl in Figure 6 (C) and b2 in Figure 7 (C)). ) to reconfirm the reversal of this phase difference relationship.

That is, after the initial processing is performed in step SM1- of the main flow of FIG. The process proceeds to the interrupt flow shown in FIG. 9, and at the same time, proceeds to the reverse phase processing flow shown in FIG. 9 in order to reconfirm the reversal of the phase difference relationship at step SM4-.

After activating the phase detection timer in step S1 of the interrupt flow in FIG. 9, it is determined in step S2 whether or not the photocoupler (15) is in an ON state, and if YES is in an ON state of deafness. In step $3, the photocabra (15) was turned on and deaf.

On the other hand, in the case of No, which is in the OFF state, the OFF state of the photocoupler (15) is memorized in step S4, and the process returns.

In the reverse phase processing flow shown in FIG. 10, in step S1, the time measured by the reverse phase detection timer is a predetermined time from the rise of the transistor (Tr) to the time corresponding to 1500 in electrical angle (that is, when the power supply frequency is 8 at 50Hz
mS, 7 m3 at 60 Hz), and only if YES after a predetermined time has elapsed, the current operating state of the photocoupler (15) is determined in step S2, and in step S3 and step $4. The operating state of the photocoupler (15) at the time of interrupt processing is read out, and if it is in the ON state at the time of the J-input processing and is in the OFF state this time, it is determined that the phase is normal in step S5, and in step S6 Then, the compressor (1) is allowed to rotate and the reverse display diode (LED) is turned off, and the process returns to step 5-M3 of the main flow of FIG. 8 above. On the other hand, it is OFF during interrupt processing.
If it is in the ON state and this time it is in the ON state, step S
In step S3, it is determined that the phase is reversed, and in step S3, the rotational drive of the compressor (1) is prohibited and the reverse phase display diode LE is set.
Turn on D and return. Also, if the interrupt processing is in the ON state or OFF state this time as well, abnormality processing is performed in step S9 and the process returns to step 5-M3 of the main flow in FIG. 8 above. Therefore, as in the above embodiment, reverse phase detection can be performed in a non-contact manner using a photocoupler (15), thereby improving its reliability and durability.

In the above embodiment, the S phase of the three-phase power supply was used as the reference phase, but it is of course possible to use other phases as the reference phase. Although this has been explained using an example, it goes without saying that even if any phase is incorrectly connected, the incorrect connection can be reliably detected.

(Effect of light) As explained above, according to the present invention, the reverse rotation of the three-phase power supply for each compression is detected using a non-contact method, and the reverse rotation of the compression is effectively prevented. , it is possible to suppress the deterioration of the function as much as possible even after long-term use, and improve reliability and durability.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of the present invention. Further, FIGS. 2 to 10 show embodiments of the present invention,
Fig. 2 is an overall schematic configuration diagram, Fig. 3 is an electric circuit diagram showing the internal structure of the negative phase protection device, Figs. 4 and 5 are flowcharts showing the operation of the IC circuit, and Fig. 6 is in normal phase. 7 is a diagram corresponding to FIG. 6 when the phase is reversed, and FIGS. 8 to 10 each show modified examples of the phase difference relationship detecting means. It is a flowchart figure. FIG. 11 is an explanatory diagram showing a conventional negative phase protection device. (1)... Compressor, (2) Three-phase power supply, 3-5... Connection wiring, (13)... First waveform creation means, (15).
...Photocoupler, (Tr)...Transistor, (1
6)...Second waveform creation means, (20)...Phase difference relationship detection means, (21)...Operation prohibition means. Fig. 1 Fig. 2] (Pressure: M) Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 11 Fig. 8 Fig. 9 Fig. 10

Claims (1)

[Claims] (1) Detect a misconnection in which the three-phase power supply (2) to the compressor (1) is connected in the opposite phase to the rotation direction of the compressor (1). 1) A negative phase protection device for a refrigerator designed to prevent reverse rotation of the compressor (1) between a predetermined reference phase and one other phase of the three-phase voltage applied to the compressor (1). a first waveform creation means (13) for creating a waveform according to the potential difference between the reference phase and the remaining one phase; a second waveform creation means (16) for creating a waveform according to the potential difference between the reference phase and the remaining one phase; phase difference relationship detection means (20) for detecting a phase difference relationship between the waveforms of the second waveform creation means (16) using the waveform of the first waveform creation means (13) as a reference waveform;
The compressor (1) further comprises an operation inhibiting means (21) for prohibiting the operation of the compressor (1) when the phase difference relationship detected by the phase difference relationship detection means (20) is different from the phase difference relationship during normal phase. Features a reverse phase protection device for refrigerators.