JP2002204524A - Operation control method for load - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically make the form of retrial differ depending on whether a malfunction generated in a power source is an unbalance or open-phase. SOLUTION: A ripple voltage v generated between both terminals of a smoothing capacitor 214 is estimated by a microcomputer 222. The larger the value of the ripple voltage v is, the fewer the number of permissible retrials is. The retrial is realized by controlling on/off of a switch 227 with a microcomputer 222. By switching the switch 227 off, a contact 212b of a relay 212 is disconnected, an R-phase output and a T-phase output obtained from a noise filter 211 are not supplied to a diode module 231, and the operation of a motor 201 is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for controlling a mode of retry for stopping / restarting a load operation.

[0002]

2. Description of the Related Art Conventionally, operation control called so-called retry for stopping / restarting operation of a load driven by a power supply has been performed. In the retry, the operation is stopped in response to the abnormality of the power supply, and thereafter, the operation is restarted after waiting for a predetermined period.

As examples, a rectifier circuit for rectifying a three-phase AC current supplied from a three-phase AC power supply, a low-pass filter for smoothing the output of the rectifier circuit, a three-phase inverter circuit for inversely converting the output of the low-pass filter, a three-phase inverter Consider a system composed of a three-phase AC load driven based on a three-phase AC output from a circuit. The low-pass filter has a smoothing capacitor, and generally generates a ripple voltage (in this specification, it indicates the absolute value) at both ends.

[0004] In addition, if an abnormality such as imbalance of the interphase voltage or open phase occurs in the three-phase AC power supply, the ripple voltage increases, sometimes reaching several times the design value. If the ripple voltage increases, an overcurrent flows through the smoothing capacitor, which may lead to a situation where the smoothing capacitor is damaged.

[0005] In order to avoid such a situation, the above retry is performed. For example, when the ripple voltage exceeds a certain threshold for more than a first predetermined time, the operation of the three-phase AC load is stopped for a second predetermined time, and then the operation is restarted.

[0006]

Under unbalanced conditions, the operation of the load is relatively easy. On the other hand, the open phase makes the operation of the load relatively difficult. However, in the related art, the threshold value of the ripple voltage is set to a single value regardless of whether the abnormality occurring in the power supply is unbalanced or phase-loss. Therefore, in the related art, even when the retry is being performed, it is not possible to classify the power supply abnormality.

The open phase is mainly caused by a mistake in connection of the power supply wiring of a device, a failure of a circuit breaker and a switch, and the likelihood of normal recovery over time is small. Therefore, in such a case, the number of retries should be reduced to prevent a failure of the three-phase inverter circuit. On the other hand, it is highly likely that the imbalance will recover to normal over time, and it is desirable to increase the number of retries to avoid frequent maintenance. However, it has been difficult to meet such a demand when the conventional technology is adopted.

The present invention has been made in view of the above circumstances, and a technique for automatically changing the retry mode, for example, the number of times, depending on whether the abnormality occurring in the power supply is unbalanced or out of phase. I will provide a.

[0009]

Means for Solving the Problems Claim 1 of the present invention
Is a load operation control method, which rectifies the polyphase alternating current (300) to load (201, 232, 21).
The retry modes (T1 to T6) for stopping / restarting the operation of the load are different based on the fluctuation (v) of the output of the rectifier (231) supplied to 4).

[0010] The present invention according to claim 2 includes:
The load operation control method according to claim 1, wherein the retry modes (T1 to T6) are different based on a magnitude of the output ripple voltage (v) of the rectifier (231).

According to the third aspect of the present invention,
3. The load operation control method according to claim 2, wherein the larger the ripple voltage (v), the longer the detection period (L1 to L1).
6) is set short, and the retry modes (T1 to T6) are different when the ripple voltage is continuously generated for the detection period set corresponding to the magnitude thereof.

According to a fourth aspect of the present invention,
The load operation control method according to claim 2 or 3, wherein the smaller the ripple voltage (v), the larger the number of times (T1 to T6) of stop / restart of the load operation is allowed.

According to a fifth aspect of the present invention, there is provided:
The load operation control method according to any one of claims 2 to 4, wherein the load (201, 232, 21
4) includes an inductive load (201) and an inverter (232) that drives the inductive load (201). As the output current of the inverter increases, the ripple voltage (Va to Vg), which is the basis for making the retry mode different, is increased. The size is set large.

According to a sixth aspect of the present invention, there is provided:
6. The load operation control method according to claim 5, wherein the magnitude of the ripple voltage serving as a basis for changing the retry modes (T <b> 1 to T <b> 6) depending on output frequencies (F <b> 1 to F <b> 4) of the inverter. 7. (Va to Vg) are set differently.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of a configuration to which the present invention is applied. FIG. 1 shows an example of a load operation system to which the present invention is applied.
FIG. 2 is a block diagram illustrating a configuration of the air conditioner. The air conditioners are roughly classified into an indoor unit 100 and an outdoor unit 200.

The indoor unit 100 includes an indoor unit-side control board 101.
, Which includes a remote controller 10
2 are connected. The operation performed on the remote controller 102 is determined by the indoor unit-side control board 101, and the content is given to the connector CN21 as a communication signal.

The outdoor unit 200 includes a motor 201 to be controlled for operation, a filter board 210, an inverter unit 220, and an outdoor unit-side control board 240. The motor 201 can be grasped as an inductive load.

The filter board 210 is provided with a three-phase AC power supply 30.
A noise filter 211 for inputting current of each phase of R phase, S phase, and T phase supplied from 0; a relay 212;
3 and a smoothing capacitor 214.

The inverter unit 220 has a semiconductor unit 230. The semiconductor unit 230 includes a diode module 231 and a transistor module 232.
And

The conduction / non-conduction of the contact 212b of the relay 212 causes the R
The output of the phase and the output of the T phase are
It is determined whether to supply to 1 or not. Contact 212
The conduction / non-conduction of b corresponds to whether or not a current is supplied to the coil 212a. The S-phase output obtained from the noise filter 211 is supplied to the diode module 231 irrespective of the conduction / non-conduction of the contact 212b. Desirably, the noise filter 211 has a surge absorber function.

The positive output terminal (shown by +) of the diode module 231 is directly connected to the transistor module 2.
32 is connected to a positive input terminal (shown by a symbol +), and a negative output terminal (shown by a symbol −) is connected to a negative input terminal (shown by a symbol −) of the transistor module 232 via a choke coil 213. You. The smoothing capacitor 214 is provided between the positive input terminal and the negative input terminal of the transistor module 232. The case where an electrolytic capacitor is adopted as the smoothing capacitor 214 is illustrated.

When the contact 212b is conducting, R
Phase, S-phase, and T-phase currents are supplied from the three-phase AC power supply 300 via the noise filter 211 to the diode module 23.
1 is supplied. The diode module 231 performs full-wave rectification of these currents and supplies the current to a low-pass filter formed by the choke coil 213 and the smoothing capacitor 214. The diode module 231 can be regarded as a rectifier alone or in combination with a low-pass filter. The output of the low-pass filter is obtained as a voltage across the smoothing capacitor 214.

The transistor module 232 switches the output of the low-pass filter at a predetermined frequency under the control of a microcomputer 222 described later. Thereby, the inverse conversion is performed, and the three-phase alternating current is supplied to the motor 201. That is, the transistor module 232 has a function as an inverter. On the other hand, the transistor module 232 and the motor 20
In combination with 1, it can be regarded as the load of the rectifier. The output of the low-pass filter is a smoothing capacitor 214
Can be grasped as a rectifier by using the diode module 231 alone or in combination with the choke coil 213, and the smoothing capacitor 214 can be grasped as a load.

The inverter unit 220 further includes a discharge resistor 223 and a current transformer 224. Discharge resistor 22
3 is connected in parallel with the smoothing capacitor 214. By using the current transformer 224, the transistor module 2
The current flowing between the connection point between the positive input terminal of P.32 and the discharge resistor 223 and the positive output terminal of the diode module 231 is measured. By measuring this current, the current flowing through the transistor module 232 can be estimated.

The inverter unit 220 further includes a voltage dividing resistor group 221 and a microcomputer 222. The voltage dividing resistor group 221 divides the voltage between both ends of the smoothing capacitor 214 to obtain a measured voltage v, which is supplied to the analog input terminal AN of the microcomputer 222. In particular,
The voltage dividing resistor group 221 includes resistors 221a, 221b, and 221c that are connected in series between the positive side end (the side marked with +) of the smoothing capacitor 214 and the negative side end. The connection point between the resistors 221a and 221b is connected to the analog input terminal AN of the microcomputer 222, and the connection point between the resistors 221b and 221c is grounded.

The outdoor unit-side control board 240 includes a connector CN
10, CN11, CN14 and fuses 241, 242. The R-phase current and the S-phase current obtained from the noise filter 211 are supplied to the fuses 241 and 242 via the connector CN10, respectively. The R-phase current via the fuse 241 is supplied to the connectors CN11 and CN11.
It branches and flows to 14. The outdoor unit 200 includes a protection switch 202 outside the outdoor unit-side control board 240, which is connected to the connector CN14. As a result, the R-phase current branches into two paths: a path directly supplied to the connector CN11 and a path supplied to the connector CN11 via the protection switch 202. The latter is expressed as an R′-phase current for convenience. The S-phase current is supplied to the connector CN11 via the fuse 242.
Given to.

The inverter unit 220 further includes a current limiting resistor 225, switches 226 and 227, and a power supply circuit 22.
8. Equipped with connectors CN1 and CN2. Connector C
N1 is a connector CN1 provided on the outdoor unit side control board 240.
1 and supplies the R-phase current and the S-phase current to the power supply circuit 2.
Give to 28. The power supply circuit 228 is the inverter unit 2
20 to generate the power required for operation.

The R-phase current is supplied to the connector CN2 via the current limiting resistor 225 and the switch 226, and the R'-phase current is supplied to the connector CN2 via the switch 227. The S-phase current is also supplied to the connector CN2. An R′-phase current and an S-phase current are supplied to the coil 212a from the connector CN2. Accordingly, when the switch 227 is turned on, the contact 212b is turned on, and the R-phase current and the T-phase current are supplied from the noise filter 211 to the diode module 231. The conduction / non-conduction of the switch 227 is controlled by the microcomputer 222 based on the measured voltage v as described later.

However, when the protection switch 202 is turned off, the contact 212b is turned off irrespective of the switch 227 being turned on. In that case, the R-phase current and the T-phase current are not supplied to the diode module 231. When the switch 226 is turned on, a bypass via the current limiting resistor 225 is set for the R-phase current.

The inverter unit 220 further includes a connector CN3, and the outdoor unit side control board 240 further includes a connector CN3.
13 are provided, and both are connected to each other. The outdoor unit side control board 240 further includes a connector CN.
15 which is connected to the connector CN21 of the indoor unit side control board 101. This allows
The operation requested by the operation of the remote controller 102 is determined by the indoor-unit-side control board 101, and the content is transmitted as a communication signal to the connectors CN21, CN15, and CN1.
3, provided to the microcomputer 222 via CN3. Based on this content, the microcomputer 2
22 controls the switching of the transistor module 232.

As described in the prior art, if an abnormality such as imbalance of phase voltage or phase loss occurs in the three-phase AC power supply, the ripple voltage generated at both ends of the smoothing capacitor 214 increases. By a known technique, the microcomputer 222 can estimate the ripple voltage from the measured voltage v.

In the present invention, the output of the rectifier for rectifying the polyphase alternating current and supplying it to the load, for example, the diode module 23
1, the motor 201 or the transistor module 232 or the smoothing capacitor 214
Of the retry for stopping / restarting the operation of the load including the above. More specifically, the manner of controlling the conduction / non-conduction of the switch 227 is made different based on the magnitude of the ripple voltage.

Generally, when an open phase of the power supply occurs, the ripple voltage generated across the smoothing capacitor 214 is smaller than that of the unbalanced state. For example, the interphase voltage between the R phase and the S phase is 199 V, the interphase voltage between the S phase and the T phase is 203 V,
In the unbalance where the inter-phase voltage between the R phase and the T phase is 195 V, an unbalance of 203-195 = 8 (V) occurs.
In such a case, the ripple voltage becomes approximately half as compared with the case where one phase is lost.

In the present invention, in view of such circumstances, control is performed to allow a larger number of load retries as the ripple voltage is smaller. It is easy for those skilled in the art to generate a program for causing a microcomputer to perform such control.

First Embodiment Based on the measured voltage v,
If the ripple voltage is estimated to be in the range of Vc (> 0) to Vg (> Vc), it is determined that the power supply is unbalanced, and the number of retries is allowed up to T1. If the ripple voltage is estimated to be larger than Vg, it is determined that the power supply has lost phase, and the number of retries is allowed up to T2 (<T1). The number of retries is
The switch 227 is turned off once to stop the operation of the motor 201, and after a predetermined time has elapsed, the switch 227 is again turned on.
, And the operation of restarting the operation of the motor 201 is grasped as one unit. After these retries have been performed the permitted number of times, the operation of the motor 201 is stopped, and the operation is not restarted spontaneously unless another operation is performed.

For example, the number of retries T1 may be infinite. As described above, the imbalance of the power supply is an abnormality in which the operation of the load is relatively easy, and there is a high possibility that the power supply will recover over time. In such a case, spontaneous resumption of operation is continued even if no separate operation is performed. On the other hand, the open phase is an abnormality in which the operation of the load becomes relatively difficult, and it is unlikely that the load will recover over time.

In this way, the mode of retry, for example, the number of times of retry can be automatically changed depending on whether the abnormality occurring in the power supply is unbalanced or out of phase. The ripple voltage threshold for making the number of retries different is
Vc and Vg are not limited to two, and may be three or more.

When the switch 227 is turned off, the motor 20
1 is output from the microcomputer 222 to the connectors CN3, CN13, CN15, and C15.
It is transmitted to the indoor unit side control board 101 via N21. Then, the indoor unit-side control board 101 causes the remote controller 102 to display, for example, that a retry is being performed. Further, since the microcomputer 222 recognizes whether the abnormality occurring in the power supply is unbalanced or open phase, the microcomputer 222 also transmits the type to the indoor unit side control board 101,
The type of abnormality that has occurred in the power supply
May be displayed.

Second Embodiment In the first embodiment, the length of the period in which the ripple voltage appears may be further considered. In the present embodiment, the ripple voltage is changed from Vc to Vg.
The retry is executed only when the period estimated to be within the range is continuously performed for L1 minutes. And the ripple voltage is V
The retry is performed only when the period estimated to be larger than g is continuously performed for L2 (<L1) minutes. FIG. 2 is a graph showing the relationship between the estimated ripple voltage, the period during which the ripple voltage is continuous, and the number of retries. Of course, it is desirable that the ripple voltage is constantly monitored and the retry control be performed immediately. In that case, if the ripple voltage is in the range of Vc to Vg, the ripple voltage is longer than the detection period L1. Is not maintained at that value, and the number of retries T1 is set in a region indicated by S1 indicated by a thick line. Also, even when the ripple voltage is higher than Vg, the ripple voltage is not maintained at that value longer than the detection period L2, and the number of retries T2 in the region indicated by S2 indicated by the thick line
Is set.

As described above, the detection period is set with respect to the magnitude of the ripple voltage, and when the ripple voltage is generated continuously beyond the detection period, the retry is performed in a different manner as in the first embodiment. Is executed.

Since the open phase is a more serious abnormality than the unbalance, by determining the retry mode in a shorter period of time, the air conditioner as the load operation system can be protected.

Third Embodiment The threshold value of the ripple voltage set in the second embodiment and the detection period corresponding to this threshold value are different from those of the transistor module 2.
32 may be set differently depending on the switching frequency of 32 and the current flowing through the transistor module 232 (referred to as “output frequency” and “output current” in this specification, respectively). The former is known by the microcomputer 222, and the latter can be detected or estimated by the current transformer 224. Therefore, the microcomputer 222 can correct the retry mode shown in the second embodiment based on any of them.

FIG. 3 is a diagram showing a retry recipe group 5 employed in the present embodiment. The recipe group 5 can be stored in a memory normally provided in the microcomputer 222.

The recipe group 5 is composed of recipes 501, 502, 503 set for each output frequency. The recipe 501 sets a retry mode when the output frequency is F1 to F2 (Hz), and the recipe 502 sets the output frequency to F2 (Hz).
The retry mode when the output frequency is F3 to F4 (Hz) is set in the recipe 503 (however, F1 <F2 <F3 <).
F4).

In each of the recipes 501, 502, and 503, a retry mode is set for each output current. For example, in the recipe 501, the output current range is 0 to 1
It is divided into the ranges of 0, 10 to 20, and 20 to 30 (A). The setting of such a range may, of course, be different for each output frequency.

In the recipe 501, the output current range is from 20 to
In the case of 30 (A), the retry mode shown in the second embodiment is set. In the figure, in the column below the column in which the range of the output current is described as 20 to 30 (A), only the ripple voltages Vc and Vg are described. Vc
In the column described as, the ripple voltage is Vc to Vg (> Vc).
And the column described as Vg shows the case where the ripple voltage is higher than Vg. The detection period below each column indicates a detection period set corresponding to each ripple voltage. As described in the second embodiment, the ripple voltage is V
In the case of being in the range of c to Vg, the detection period is L
When the ripple voltage is greater than Vg, L2 (minute) is set as the detection period. When a ripple voltage corresponding to the detection period is generated over the detection period or more, the number of times T described in the column of the number of retries located further down in the figure.
At 1 and T2, a retry is executed. As described above, L1
> L2, T1> T2.

In the column below the column in which the range of the output current is described as 10 to 20 (A), Vb, V
Only e is described. The column described as Vb indicates the case where the ripple voltage is in the range of Vb to Ve (> Vb).
The column described with e shows the case where the ripple voltage is higher than Ve. And the ripple voltage is Vb ~
In the case of being within the range of Ve, the detection period is L5
(Min), when the ripple voltage is larger than Ve, L6 (min) is set as the detection period. The ripple voltage becomes V over L5 (minutes).
If it is estimated that it is in the range of b to Ve, it is retried at the number of times T5. If it is estimated that the ripple voltage is higher than Ve over L6 (minutes), the retry is performed at the number of times T6. L5> L6, T5> T6 are set.

In the columns below the column in which the output current range is described as 0 to 10 (A), the ripple voltages Va, Vd
Is described only. The column described as Va indicates the case where the ripple voltage is in the range of Va to Vd (> Va).
The column described as “<” indicates the case where the ripple voltage is higher than Vd. And the ripple voltage is Va ~
In the case of being in the range of Vd, the detection period is L3
When (min) is larger than the ripple voltage, L4 (min) is set as the detection period. The ripple voltage is equal to or higher than L3 (minutes).
If it is estimated that it is in the range of a to Vd, retry is performed at the number of times T3. If it is estimated that the ripple voltage is higher than Vd over L4 (minutes), the retry is performed at the number of times T4. L3> L4, T3> T4 are set.

In general, as the output current increases, the ripple voltage also increases, so that Va <Vb <Vc, Vd <Ve <V
It is desirable to set to g. L4 = L5, L6 =
L1 may be set.

For recipes 502 and 503, the recipe 5
01 is set. In recipe 502, recipe 50
Since the setting for the case where the output frequency is higher than 1 is performed, the value of the ripple voltage serving as the threshold value may be set higher than that of the recipe 501. The same applies to the recipe 503.

In the present embodiment, since the retry mode is made different according to the output current and the output frequency, fine control is performed according to the load, and damage to the smoothing capacitor 214 that can be grasped as a part of the load is performed. The effect of prevention can be enhanced.

[0052]

According to the load operation control method according to the first aspect of the present invention, the load operation can be controlled in accordance with the power environment of the polyphase alternating current.

According to the load operation control method according to the second aspect of the present invention, the load operation can be controlled by judging the power environment of the polyphase alternating current by the ripple voltage.

According to the load operation control method according to the third aspect of the present invention, the load can be protected by determining the retry mode in a shorter period of time for a serious abnormality.

According to the load operation control method according to the fourth aspect of the present invention, the retry itself can be stopped earlier as the load operation becomes more difficult, and the load can be protected.

According to the load operation control method of the present invention, fine control can be performed according to the load.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating the configuration of an air conditioner to which the present invention is applied.

FIG. 2 is a graph showing an operation of the second exemplary embodiment of the present invention.

FIG. 3 is a diagram illustrating a third embodiment of the present invention.

[Explanation of symbols]

 201 motor 213 choke coil 214 smoothing capacitor 231 diode module 232 transistor module 300 three-phase AC power supply

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Toshio Miyamoto 1304 Kanaokacho, Sakai-shi, Osaka Daikin Industries Inside Kanaoka Plant of Sakai Seisakusho Co., Ltd. (72) Masafumi Hashimoto 1304 Kanaokacho, Sakai-shi, Osaka Daikin Industries, Ltd. 5H007 AA17 BB11 CA01 CC01 DA05 DB01 DB12 DB13 FA12

Claims (6)

[Claims] 1. A rectifier for rectifying a polyphase alternating current (300) and a load (2).
01, 232, 214), the operation of the load is stopped /
A load operation control method in which retry modes (T1 to T6) to be restarted are different. 2. The load operation control method according to claim 1, wherein the retry modes (T1 to T6) are different based on the magnitude of the ripple voltage (v) of the output of the rectifier (231). 3. The detection period (L1 to L6) is set to be shorter as the ripple voltage (v) is larger, and the ripple voltage is continuously generated for more than the detection period set in accordance with the magnitude. The load operation control method according to claim 2, wherein the retry modes (T1 to T6) are different in the case of performing the operation. 4. The load operation control method according to claim 2, wherein the smaller the ripple voltage (v), the larger the number of times (T1 to T6) of stop / restart of the load operation is allowed. . 5. The load (201, 232, 214) includes an inductive load (201) and an inverter (232) for driving the inductive load (201). The larger the output current of the inverter, the more different the retry manner. The ripple voltage (Va ~
The load operation control method according to claim 2, wherein the magnitude of Vg) is set to be large. 6. An output frequency (F1 to F1) of the inverter.
4), the magnitudes of the ripple voltages (Va to Va) which are the basis for differentiating the retry modes (T1 to T6).
The load operation control method according to claim 5, wherein Vg) is set differently.