JPS6329175A - Feed controller for refrigerator - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention supplies frequency-controlled power from an inverter power supply to a variable capacity compressor that constitutes a refrigeration system, and also supplies power from a commercial power source to a variable capacity compressor by switching a switch. The present invention relates to a power supply control device for a refrigeration system that directly supplies power to a variable compressor.

(b) Conventional technology For example, Japanese Utility Model Application Publication No. 58-1885.54 discloses a plurality of refrigeration cycles each having a variable capacity compressor, an inverter circuit for driving a drive motor of each of the compressors, A plurality of switches selectively form a current conduction path from the inverter circuit to each of the drive motors or from the power source to each drive motor, and a plurality of switches that selectively form a current conduction path from the inverter circuit to each of the drive motors, and a plurality of switches that control each of the switches and control the inverter according to the size of the load. A refrigeration cycle device is disclosed that includes a control section that controls a circuit.

(c) Problems to be solved by the invention In the above conventional technology, one of the compressors is driven by an inverter circuit depending on the size of the load, and the other compressors are driven by the power supply voltage. When a failure occurs in the inverter circuit or the temperature sensor, for example, if an overcurrent flows through the inverter circuit or if the temperature inside the refrigerator is no longer controlled, the inverter circuit stops operating. Power is no longer supplied to the compressor, and only the compressor that is supplied with power directly from the power source is operated.
Therefore, when the cooling load is large, a problem arises in that the temperature inside the refrigerator increases.

The present invention aims to solve the above problems.

(d) Means for solving the problems The present invention has been made to solve the above problems.
To explain based on an example below, three-phase commercial power supply (1)
An inverter power supply (7) that supplies frequency-controlled power to the variable-capacity first and second humbresses (5) and (6) that are connected to the refrigeration system and constitutes a refrigeration system, and a first temperature control unit provided in the refrigerator. A controller (15) that inputs a temperature signal from a sensor (43) and outputs a frequency signal that determines the frequency of the power to an inverter power source (7), and an inverter power source (7).
) to the first and second compressors (5) and (6), and from the commercial power supply (1) to the first and second compressors (5)
The first to fourth normally open switches (85)<95)(11S)( In the power supply control device for a refrigeration system equipped with an inverter power supply (7
> When power is being supplied to the first and second compressors (5) and (6), temperature control becomes impossible due to a disconnection of the first temperature sensor (43), for example, and the temperature inside the refrigerator is set in advance. a third temperature sensor (53) that detects that the temperature has reached the upper limit temperature range or the lower limit temperature range; and a timer circuit (31T) that outputs a signal when the temperature sensor continues to detect the temperature for a predetermined period of time. Based on the signal from this timer circuit (31T), the first and second normally open switches (ss) (
95) and turn off the third and fourth normally open switches (
11s) (125) to supply commercial power to the first and second compressors (5) and (6), and to control energization based on the internal temperature of the refrigerator. It is.

(e) According to the working example, when frequency-controlled power is supplied from the inverter w, 1 (7) to the first or second compressor (5) or (6), the inverter power supply (7) If an overcurrent occurs, or if temperature control becomes impossible due to a defect in the first temperature sensor (43) or a defect in the board in the controller (15), etc., the commercial operation controller
- The roll board (32) operates, power is supplied directly from the commercial power source to the first and second combustors (5x6), and the second temperature sensor (52) detects the temperature inside the refrigerator and Power supply to each compressor is controlled based on the temperature, and temperature control is performed.

(F) Example Hereinafter, an example of the present invention will be described in detail based on the drawings.

FIG. 1 shows a schematic block diagram of a power supply control device for a refrigeration system, in which (A) is an inverter operation circuit, (B) is a commercial operation circuit, (15) is a controller, and this controller is an I10 board (40), It consists of a control board (41) and a display section (42), and for example, a temperature signal is given to the 170 board (40) from a first temperature sensor (43) that detects the temperature inside the refrigerator. substrate(
45) and an inverter IC (46>), frequency-controlled power is supplied from the inverter Tri and source (7) to three-phase 1st and 20th three-phase compressors (hereinafter referred to as combus). (5), (6>) is output to the compressor operation circuit (47).Furthermore, (48) is an operation circuit for inverter operation, and the operation of this operation circuit causes the first and second combinations (5), One operation and simultaneous operation of (6) are controlled.In addition, (32) is a commercial operation control board, (50> is a commercial operation operation circuit, (31) is a temperature report board and a timer circuit (31T). )
It is also equipped with a commercial operation control board (32)
Second and third temperature sensors (52) and (53) for sensing the temperature inside the refrigerator are connected to the temperature alarm board (31>), respectively.

The operation in the block diagram of the above operation control device will be explained. Now, the I10 board (40) operates based on the signal from the first temperature sensor (43) and performs signal processing.
A signal is output to the control board (41), the data is processed by this control board, and then the I10 board (40)
The frequency signal from this 170 board can be output to the inverter power supply (7), and the frequency-controlled power can be supplied from the inverter power supply (7) to the first or second combination (5) or (6). The refrigeration cycle is operated to perform cooling operation. Further, data-processed temperature signals and the like are given from the control board (41) to the display section (42), and the internal temperature and the like can be displayed on the display section (42).

As mentioned above, when the first and second combinations <5> (6) are performing inverter operation, for example, the inverter IC (
46) fails and overcurrent flows through the power transistors that make up the inverter IC, the inverter IC (
46) turns off this power transistor and outputs a failure signal to the inverter board (45). Then, the inverter board (45) stops outputting the frequency signal to the inverter IC (46) and outputs a failure signal to the control board (32). Here, the control board (32) detects the presence or absence of the failure signal at a predetermined interval, for example, at a rate of 7 times every 10 minutes, that is, approximately every 86 seconds, and when the failure signal is detected repeatedly 7 times, the control board (32) ) operates and outputs a switching signal to commercial operation. Then, the I10 board (40) operates based on this signal, thereby switching the inverter operation operation circuit (48) to the inverter operation stop side. Also, the commercial operation control board (32) is energized by the operation of the 110 board (40), and the second
The operation is started based on the temperature signal from the sensor (52). By the operation of this commercial operation control board (32), the commercial operation operation circuit (50) operates and the first and second
Commercial power can be directly supplied to the kelp (5) and (6) from the 3-phase AC power supply.

The commercial operation control board (32) was inputting the temperature signal inside the refrigerator from the second temperature sensor (52) at the same time that commercial power started to be supplied to the first and second kelp (5) and (6).
is based on the temperature signal, the first and second kelp (5) (
6) Outputs a signal to control the supply of commercial power to. In response to this signal, the commercial operation operation circuit (50) operates to turn on and off the electricity to the first and second combinations (5) and (6), thereby operating the first and second combinations (5) and (6). , the temperature inside the refrigerator is kept approximately constant due to stoppage, that is, commercial operation. Incidentally, at this time, the change in the temperature inside the refrigerator becomes larger than when the first and second kelp (5) and (6) are operated with the inverter.

Furthermore, when inverter operation is performed, a failure such as a disconnection of the first temperature sensor (43), or a failure of the I10 board
40> or the like, that is, a broken pattern or disconnection, a disconnection of the signal line between the respective boards, etc., an incorrect frequency signal is given to the inverter power supply (7). For this reason,
Electric power with a frequency unrelated to the temperature inside the refrigerator is given from the inverter power supply (7) to the first and second combs <5> (6), and the cooling capacity of the refrigeration cycle due to the operating capacity of these combs is independent of the temperature inside the refrigerator. Therefore, the internal temperature rises or falls below the set temperature. The third temperature sensor (53) senses the temperature inside the refrigerator and provides a temperature signal to the temperature alarm board <31). If the temperature inside the refrigerator exceeds the upper limit temperature range or the lower limit temperature range and this state continues for the set time, the timer circuit (30T> of the temperature alarm board (31) outputs a signal and the commercial operation control board (32 ) is energized and starts operating based on the temperature signal from the second sensor (52).Then, as in the case where the inverter IC (46) fails, the first and second combinations (5) and (6) Driving begins.

FIG. 1 shows a schematic circuit diagram of a power supply control device according to the present invention, in which (1) is a three-phase commercial power supply, (2a), (2b), (2
C) are first, second, and third power lines, respectively, and each power line (28), (2b), (2c) is connected to the three-phase commercial power source (1) at an outlet (3). Also, (4) is a reverse phase prevention relay, and this reverse phase prevention relay (4) is the first,
The connection to the second and third power supply lines <2a), <2b), and (2c) is complete. Furthermore, the first and second kelp (5) <6
) have v, i, second and third power lines (2a), (2b
), (2C) can supply power. Also, (7) is the inverter 1 that supplies frequency-controlled power to the first and second combinations (5) and (6) as described above! The first and second relay switches <8> of the first and second relays (8) and (9) are connected between the inverter power supply (7) and each combination (5) <6>.
5) (95) is provided, and the first, second, and third
'F! source lines (2a), (2b), (2C) and the first,
What is the second comb (5) (6)? The third and fourth relays (11)
(12) 3rd and 4th relay switches (115) (12)
5) can be read directly.

Further, a power supply cutoff switch (4S) of the negative phase prevention relay (4) is provided on the control circuit side of the third power line (2b) from the negative phase prevention relay (4).

Further, (15) is a controller, (16) is a manual commercial operation selector switch, (16a) is a contact on the inverter operation side (hereinafter referred to as the first contact), and (16b) is a contact on the commercial operation side (hereinafter referred to as the second contact). (referred to as a contact point). A normally open fifth contact point is connected between the first contact point (16a) and the second contact point (16b).
, 6th and 7th relay switches (215) (2251) (
2351) can be connected in parallel, and (225!>
is a normally closed sixth relay switch, and this normally closed sixth relay switch (2251) can be connected to the first relay (8) via the first combination energization switch (26) of the controller (15), and the controller ( 15) is connected to the second relay (9) via the second comb energization switch (27).

The second contact (16b) is the eighth relay switch (24s
1) and a normally closed commercial operation control switch (15
5) through the third relay 11) or the fourth relay (12)
) is not connected. Also, (23) and (235*) are the eighth relay and the normally open eighth relay switch, (21) is the first relay, <28) is the commercial operation selector switch of the controller (15), and (30) is the 9 relays are connected to the first contact (16a) via the temperature alarm switch (315).

Furthermore, (24) is the eighth relay, (305) is the normally open ninth relay switch, and (245m) is the normally open third relay switch. Further, (22) is a second relay, (31) is a temperature alarm board, and (32) is a commercial operation control board. Further, (43), (52), and (53) are first, second, and third temperature sensors that respectively sense the temperature inside the refrigerator and output a temperature signal.

The operation of the above circuit will be explained below. Now, the first, second, and third power lines (2a) (2b) (2c) of the refrigeration equipment
) is connected to the outlet (3), the three-phase commercial power supply (
1) Phase sequence and first, second, and third power supply lines (2a) (2
b) The phase sequence of (2c), that is, the first and second kelp (5) (6
), the reverse phase prevention relay (4) detects that the phase orders are equal and keeps the power supply cutoff switch (4S) on. Also, 3-phase commercial power supply (1)
Phase sequence and first, second, and third power lines (2a) (2b)
When the phase order (2c) is different, the reverse phase prevention relay (4) detects that the phase order is different and operates, and the power supply cutoff switch (4S) is turned off.

When the power supply cutoff switch (4S) is turned off, the first and second relays (8) (9), and the third and fourth relays (11) (1
2) is de-energized regardless of whether the other switches are on or off, and the first and second relay switches (85) (95) and
Both the third and fourth relay switches (115) and (125) continue to be off. Therefore, even though the first, second, and third power lines (2a), (2b, and 2c) are connected to the commercial power supply (1), the first and second combs (5X6) continue to stop. . The administrator of the refrigeration equipment noticed that the refrigeration equipment had stopped, and the first, second, and third power lines (2a) (2
b) <2c) By switching the connection at the outlet (3) of the 2 power supply lines, the 3-phase commercial power supply (1) and the 1st, 2nd, 31i source lines (2a) (2b) (2c)
The phase order of is equal to For this reason, the reverse phase prevention relay (4
) detects that the respective phase orders are equal and turns on the power supply cutoff switch (4S).

When the power supply cutoff switch (4S) is on, for example, if the first comb energization switch (26) of the controller (15) is turned on, the first contact of the power supply cutoff switch (4S) and the commercial operation selector switch (16) is turned on. (L6a), the first relay (11) is energized via the normally closed sixth relay switch (2252>, and the first combination energization switch (26), and the first relay switch (8S) is turned on to turn on the first combination (
5) is supplied with frequency-controlled power from an inverter power supply (7). Therefore, frequency-controlled power is supplied to the first kelp (5) based on the temperature inside the refrigerator, and the temperature inside the refrigerator is kept substantially constant. Further, when the temperature inside the refrigerator tends to be high, the second kelp energization switch (27) is turned on and the second kelp (6) also starts operating in the same manner as described above. Further, when one of the first and second combs (5) and (6) is operated, the respective combs are operated alternately.

As mentioned above, when the first and second combinations (5) and (6) are performing inverter operation by supplying power from the inverter N and source 7), for example, when the power transistors constituting the inverter power R (7) When an overcurrent occurs, a fault signal is output from the inverter power supply (7) to the controller (15).Based on this fault signal, the controller (
The commercial operation selector switch (28) of No. 15) is turned on, and the
The relay (21) is energized and the normally open relay switch (21)
5) is turned on. Therefore, the commercial operation control board (32) is energized, the sixth relay (22) is energized, the normally closed sixth relay switch (22S*) is turned off, and the first and second relays (11) (12S*) are turned off. ) becomes de-energized, the first and second normally open switches (8S) (9S) are both turned off,
From the inverter power supply (7) to the first and second combinations (5) (6)
) will be stopped. □Also, the normally closed second relay switch (22S+) is turned on. Also, the ninth relay (30) is de-energized and the ninth relay switch (305) is turned on and the eighth
Relay (24) is energized.

The fourth relay switch (
24S+ > (245H turns on, 3rd and 4th relays (
11) and (12) are both energized, and the third and fourth normally open switches (IIs) (125) are both turned on. By turning on these switches, the first and second combinations (5) and (6) are fully supplied with AC power from the three-phase AC power supply (1), and the first and second combinations (5) and (6) begin commercial operation. do. Incidentally, at this time, a buzzer, a lamp, or the like may be operated to notify that commercial operation has started. In addition, the commercial operation control board (32) is energized, and the second temperature sensor (52)
Based on this temperature signal, the commercial operation control switch (ISS") is turned on and off, and the energization of the third and fourth relays <11) and (12) is controlled. Therefore, the third and fourth normally closed switches (115)
(125) turns on and off, and the first and second combs (5) (6
) Due to the start and stop associated with commercial operation, the temperature inside the refrigerator fluctuates more widely than during inverter operation, but the temperature inside the refrigerator is maintained at approximately the set temperature.

Further, for example, if a failure such as a disconnection occurs in the first temperature sensor (43) that outputs a temperature signal inside the refrigerator to the controller (15), the frequency control by the controller (15) becomes inaccurate, and Although the internal temperature tends to rise, if the frequency of the power from the inverter power supply (7) based on the frequency signal from the controller (15) is low, the internal temperature will rise. The third temperature sensor (53) connected to the temperature alarm board (31) senses this temperature inside the refrigerator, and when the temperature inside the refrigerator falls within the upper limit temperature range that is higher than the set temperature by, for example, 10"C or more, the temperature Alarm board (3
The timer circuit (31T) provided in step 1) starts operating. When the temperature inside the refrigerator continues to be within the upper limit temperature range for two hours, for example, the timer circuit (31T) counts up, and as the count increases, the temperature alarm board (31) switches the temperature alarm switch (315). Turn on. When the switch (315) is turned on, the ninth relay (30> is de-energized, and the ninth relay switch (305)
is turned on, and thereafter, the refrigeration system shifts from inverter operation to commercial operation in the same way as when switching from inverter operation to commercial operation by turning on the commercial operation changeover switch (28).

In addition, the frequency control by the controller (15) becomes inaccurate, and the temperature inside the refrigerator tends to decrease, and when the temperature inside the refrigerator reaches the lower limit temperature range, for example, 5°C or more lower than the set temperature, and a predetermined period of time has elapsed, the temperature also decreases. The alarm board (31> turns on the temperature alarm switch (315) and turns on the first and second combinations (5) (6).
) operation from inverter operation to commercial operation.

When X* is turned on for the first time after installing a refrigeration system, or when the power is turned on after the refrigeration system has been shut down to clean the interior of a prefabricated low-temperature refrigerator equipped with a refrigeration system. , that is, inverter operation is started during pulldown. However, at this time, the temperature inside the refrigerator is high and within the upper limit temperature range, and the third temperature sensor (
The timer circuit (31T) of the temperature alarm board (31) starts operating according to the temperature signal from the temperature alarm board (31). At this time, if the temperature inside the refrigerator falls below the upper limit temperature range due to the inverter operation before a predetermined period of time has elapsed after the timer circuit (31T) starts operating, the timer circuit (31T) stops operating. After stopping, the temperature alarm switch (315) continues to be off, the inverter operation continues, and the temperature inside the refrigerator gradually approaches the set temperature. Therefore, even if the humidity inside the warehouse temporarily exceeds the upper limit temperature, such as when the power is turned on or when storing items are brought in or taken out, an immediate switch from inverter operation to commercial operation is avoided.

Therefore, when frequency-controlled power is supplied from the inverter power source (7) to the first or second combination (5) or (6) and inverter operation is performed, for example, the power transistor of the inverter IC (46) may fail. or when an overcurrent occurs due to the occurrence of an overcurrent, a disconnection or short circuit in the first temperature sensor (43), a disconnection or disconnection in the pattern of each board in the controller (15) or the inverter board (45), or a disconnection in the signal line between the boards, etc. As a result, power with a frequency unrelated to the temperature inside the river is transferred from the inverter power supply (7) to the first and second combs (5).
(6) and when the internal temperature reaches the preset upper or lower limit temperature range, the inverter power supply (7) is activated by the controller (15) or temperature alarm board (31).
Almost at the same time as the power supply from the main unit stops, commercial power is supplied, and the first and second combinations (5) and (6) operate the commercial operation control board (32) based on the temperature signal from the second temperature sensor (52). Commercial operation control switch (27)
If operation control is lost due to on/off of Inverter operation is switched to commercial operation, temperature control is performed, and the temperature inside the refrigerator is maintained at approximately the set temperature, so damage to stored items can be avoided.

It should be noted that the present invention is not limited to the above-mentioned embodiments. For example, even in a refrigeration system equipped with one kelp or three or more kelp, when a failure of the impark power supply or temperature sensor, etc. occurs, the automatic By switching from inverter operation to commercial operation at the same time, the same effects as in the above embodiment can be obtained.

(G) Effects of the Invention Since the present invention is a power supply control device for a refrigeration equipment as explained in the above embodiment, for example, when the inverter is operated or due to a defective temperature sensor, temperature control is not performed and the temperature inside the refrigerator is the upper limit. When the temperature falls within the temperature range or the lower limit temperature range and this condition continues for a predetermined period of time, the changeover switch that switches between the inverter power source and the commercial power source operates to perform a so-called failsafe and automatically switch the commercial power source to the compressor. Electricity is now supplied from the warehouse, switching to commercial operation, and temperature control is performed, so even if the above-mentioned failure occurs, the temperature inside the refrigerator will be maintained at approximately the set temperature, and as a result, damage to stored items will be avoided. be able to.

[Brief explanation of the drawing]

1 to 3 show one embodiment of the present invention, FIG. 1 is a schematic block diagram of the power supply control device, FIG. 2 is a flowchart showing the operating state of the compressor, and FIG. 3 is the power supply control device. FIG. (1)...3-phase commercial power supply, (5)(6)...1st
, second compressor, (7)...inverter power supply,
(8) (9) (11) (12)... 1st to 4th relay, (15)... Controller, (31T)...
Timer circuit, (53)...Third temperature sensor. Applicant: Sanyo Electric Co., Ltd. and one other agent Patent attorney: Takuji Nishino and one other person Figure 3 Figure 2

Claims (1)

[Claims] 1. An inverter power supply that is connected to a commercial power source and supplies frequency-controlled power to a variable capacity compressor that constitutes a refrigeration system, and a signal from a temperature sensor installed inside the refrigerator that is input to the frequency-controlled power supply to the inverter power supply. A power supply control device for a refrigeration system, comprising: a controller that outputs a signal; and a changeover switch that selectively switches between an energizing path from the inverter power source to the compressor and a energizing path from the commercial power source to the compressor. When power is being supplied from the power source to the compressor,
A temperature sensor detects when the temperature inside the refrigerator reaches a preset upper limit temperature range or lower limit temperature range, and the detection of the upper limit temperature range or the lower limit temperature range of the inside temperature by this temperature sensor continues for a predetermined period of time. and a timer circuit that outputs a time signal, and the changeover switch is switched to the commercial power supply side based on the signal from the timer circuit to control the temperature inside the refrigerator. Device.