JPS6111827A - Control device of power supply for freezing and air conditioning - Google Patents

Abstract

PURPOSE:To reduce the capacity of a transformer by feeding back the change of a freezing/air conditioning temperature to a control device for turning on/off freezers/air conditioners as a set point necessary for the protection of the transformer. CONSTITUTION:The freezers/air conditioners 1a-1n are connected to the oil- immersed transformer 2 through electromagnetic contacts 11a-11n. A sensor 12 for measuring the peripheral temperatur of the transformer 2 is arranged at the vicinity of the transformer 2. A rated value of the transformer 2 is set in a setting part 7. The detected output of a sensor 15 for detecting the temperatures of rooms cooled by the freezers/air conditioners 1a-1n is applied to a peripheral temperature input part 13 together with the data of the sensor 12. An operation part 8 calculates a rated current, a load ratio, etc. of the transformer 2 on the basis of the data of a transformer current input part 6, the peripheral temperature input part 13 and a setting part 7.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a power supply control device for a refrigeration air conditioner that temporarily changes the capacity of a transformer voltage depending on a change in the room temperature of the refrigeration air conditioner.

[Prior art]

As a conventional rice cultivation device, the one shown in FIG. 1 is known. In this FIG. 1, 11 to 1·n are refrigeration equipment, air conditioning equipment, etc., which are loads on the transformer, and these refrigeration equipment and air conditioning equipment 1a to 1n are electromagnetic contactors 11a to 11n.
It is connected to the secondary side of an oil-immersed transformer 2 (hereinafter referred to as a transformer) via.

The primary side of this transformer 20 is connected to the power line 3. The current on the secondary side of the transformer 2 is detected by a current converter 4, and the output of this current converter 4 is detected by the controller 1.
4 is sent to the transformer current value input section 6.

Further, a sensor 12 for measuring the temperature around the transformer is provided near the transformer 2. 12 detects the temperature around the transformer 2. The output of this sensor 12 (D- output is input to the ambient temperature value input section 13, transformer current value input section 61, ambient temperature value input section 13°, and the output of the setting section I is sent to the calculation section 8. It looks like this.

The output of the calculation section 8 and the output of the storage section 9 are sent to an output control section 10.
The opening/closing control of the electromagnetic contactors 11a to 11a to 11a is performed based on the output.

Next, the operation will be explained. Refrigeration equipment, air conditioning equipment 1a~
When 1n is operated, a negative '#I is generated, so current flows through the transformer 2. This current value is inputted from the current converter 4 to the transformer current value input section 6. Further, the transformer ambient temperature is inputted from the sensor 12 to the ambient temperature value input section 13 .

On the other hand, in the setting section 1, the rated capacity, rated voltage, number of phases 2 time constant, and loss ratio of the transformer 2 are set in advance.

The highest point oil temperature rise is set. The calculation section 8 calculates the rated current of the transformer 2 based on the data from the transformer current value input section 62, the ambient temperature value input i1s, and the setting section T.

The load factor, oil temperature in the transformer, maximum winding temperature, and life loss rate are calculated as follows.

Here, T: Transformer ambient temperature R: Loss ratio Ratio of load loss to no-load loss at constant load τ: Time constant θθN: Highest point oil temperature rise - Maximum temperature rise at the highest point of oil temperature winding Temperature θ, = G (θθ, Kn, T) - 1" The life of an oil-immersed cryostat depends on the deterioration of the insulator, but the things that have the biggest influence on this deterioration are the oil temperature and the winding temperature. Insulation According to the law of material deterioration, the life of the transformer is Y = 'a - EXP
(-'b, θH)1. . (6) Here, a and b are constants.

Next, if the reference life is Yo, then YO is determined from the reference maximum winding temperature θHO, and YO = a-EX
P, ('-'b-θHci), --(6)
It becomes ゛. Therefore, if we take the ratio to life Y (life loss rate), then Y=YO-ExP (-b ・(θR-θno))
= (8) Generally, θno = 95°C, Yo = 30
It is said to be the year. Now, if we continue to operate at the maximum winding temperature θH1, the life Y1 will be as follows from equation (S): Yl-Yo, E X P (b ・(θa1-8go)
)---(g). When the transformer is operated for h1 hours in this state, the life loss v1 is: v1=-...(10) When v1=1, the transformer's life is said to have come to an end.

Normally, the load on the transformer changes with time, so the maximum winding temperature θ■ also changes with time, and if time is t, it can be expressed as θn(t). Further, the life loss rate can also be expressed as v(t). Therefore, a certain time t1 and a certain time t2
If time t1 = o, then the life loss V2 during starting is
is calculated, and the lifespan Y2 up to t2 is: Y2=V2°Y0 (13) The remaining 9 lifespans Y2 are: Y2'=YO-(1-V2) ---(14). If the life loss rate v (t) is monitored, the standard life Yo operation can be achieved.
In this step, equations (1) to (7) are calculated at certain fixed time intervals and outputted to the output control section 10. In the storage unit 9,
Target values (load cutoff and load load coefficients) are stored in advance for each of the load factor, oil temperature, winding temperature, and life loss rate.

In the output control section 10, the output of the calculation section 8 and the storage section 9
If any one of the load factor, oil temperature, winding temperature, and life loss rate exceeds the new coefficient, the electrode contactors 11&~11n are sequentially opened and all of them meet the input coefficient. If it falls below, the refrigeration equipment and air conditioners 1a to 1n are controlled by sequentially closing the electromagnetic contactors 116 to 11n.

Conventional transformer control devices are configured as described above, and since the control is only for the purpose of protecting the transformer, it requires frequent settings and is time-consuming in order to reduce the power consumption of the refrigeration and air conditioning equipment. Moreover, if the set values are incorrect, the necessary refrigeration and air conditioning may not be performed, and electricity consumption may not be suppressed.

[Summary of the invention]

This invention was made with the purpose of improving this drawback, and the change in the refrigeration and air conditioning temperature is fed back to the control device as a set value necessary for protecting the transformer, so that even when the load on the transformer is small, the refrigeration equipment and the air conditioning This invention proposes a power supply control device for refrigeration and air conditioning that can suppress power consumption by enabling demand control of power supply to the device by a control device. [Embodiments of the Invention] This invention will be described below. An embodiment of the power supply control device for refrigeration and air conditioning will be described based on the drawings. FIG. 2 is a block diagram showing the configuration of an embodiment of the present invention.

In these first and second figures, in order to avoid duplicate explanation,
The same parts as those in FIG. 1m are given the same reference numerals, and the explanation thereof will be omitted, and the parts different from those in FIG. 1 will be mainly described.

As is clear from comparing this Figure 2 with Figure 1,
In the figure, a temperature sensor 15 is newly provided. That is, this temperature measurement sensor 15 is a refrigeration device,
It detects the temperature of the room cooled by the air conditioners 18 to 1n, and its detection output is the ambient temperature value human power section 13.
It is designed to be sent to The other configurations are the same as in FIG. 1.

Next, the operation of the refrigeration and air conditioning power supply control device of the present invention configured as described above will be explained.

In explaining this operation, only the features of the present invention will be mainly described.

When the refrigeration and air conditioners ia to 1n are operated, the temperature of the room changes, and the ambient temperature value detected by the salinity measurement sensor 15 is input to the input section 13.

On the other hand, in the setting section 7, when the control temperature T is set in advance, the value of the temperature measurement sensor 15, whose value of i is stored in the storage section 9, is compared in the calculation section 8, and Ta≦(T-α engineering). In the case of 0, change the rated capacity in the above formula to a value smaller by β%.After that, the measured temperature Ts and the control temperature T are compared again, and if Ts≦(T−αl), the rated capacity is determined again. The fringe capacitance is further changed to a smaller value by β%.

Furthermore, if Ts ≥ (T + a? t') after the time, the rated capacity is changed to a value larger by β%.Furthermore, if Ta ≥ (T + α2) after the time, the rated capacity is changed to a value larger by β%. However, it cannot take a value greater than the initially input capacity.Also, (T+α2)>Tl!>(T-αl
), the rated capacity will not change. The above T, α1. α
2. β can be input into the setting section 1 as an arbitrary value.

Although β is expressed as a percentage in the above embodiment, it may be an absolute value such as KvA. It is also possible to use a device that can read and store the changed rated capacity at any time. Furthermore, the gate pressure regulator 2 can be used not only in oil but also in a dry type.

〔Effect of the invention〕

As explained above, this invention feeds back changes in the refrigeration and air conditioning temperature to the control device that performs power-on and shut-off control of the refrigeration equipment and air conditioner, which serve as loads on the transformer, as set values necessary for protecting the transformer. refrigeration system even when the load on the transformer is small.

Since the power supply to the air conditioner can be demand-controlled by the control device, the power supply equipment can be configured to require the minimum transformer capacity for the maximum annual load of refrigeration and air conditioning. Even if the load changes, the capacity of the transformer can be controlled to be the minimum capacity corresponding to the load, and it also has the effect of providing a demand control function for refrigeration and air conditioning that can suppress power consumption.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a conventional power supply control device for refrigeration and air conditioning, and FIG. 2 is a schematic diagram of an embodiment of the power supply control device for refrigeration and air conditioning according to the present invention. 1a to 1n... Refrigeration device, air conditioner, 2... Oil-immersed transformer, 3... Power line, 4... Transformer current converter,
6...Transformer current value input section, 7...Setting section, 8...
- Arithmetic unit, 9... Storage unit, 10... Output control unit, 1
18 to 11n...Magnetic contactor, 12...Temperature measurement sensor, °13...Ambient temperature value input section, 14...Control device, 15...Temperature measurement sensor Note that the same reference numerals are used in the drawings. indicate the same or equivalent parts.・Agent Masuo Oiwa (and 2 others) Figure 1 Figure 2 Procedure amendment (voluntary) 1. Indication of the incident: Patent Application No. 134588/1988 2,
Title of the invention Refrigeration and air conditioning power supply control device 3, Person making the amendment Representative Hitoshi Katayama Department 5, Subject of amendment (1) Claims column of the specification (2) Detailed description of the invention in the specification Column 6, Contents of amendment (1) The claims of the specification are amended as shown in the attached sheet. (2) Correct the formula (2) on page 4 of the specification. 7. Attached documents (1) A document stating the entire text of the amended scope of claims. 1 document stating the entire text of the amended scope of claims. 2. Claims Multiple refrigeration equipment, air conditioning equipment, This refrigeration device. A transformer that supplies power to the air conditioner, a transformer and the above-mentioned refrigeration system, an electromagnetic contactor that is connected between the air conditioner and supplies and cuts off power to the refrigeration system and the air conditioner, and a A sensor for measuring the ambient temperature of a transformer that detects the ambient temperature, a sensor for measuring the temperature that detects the temperature of a room cooled by the above-mentioned refrigeration device and an air conditioner, and a sensor for measuring the current of the above-mentioned transformer and the ambient temperature of the above-mentioned transformer. The detected output of the output and temperature measurement sensor, and the preset rated capacity, rated voltage, and 1-phase time constant of the transformer. The rated capacity of the transformer is changed by controlling the opening and closing of the magnetic contactor by calculating the load factor for the rated capacity of the transformer, the insulation temperature, the temperature of one winding, and the life loss based on the loss ratio and the rise in oil temperature at the highest point. A power supply control device for refrigeration and air conditioning, comprising a control device for controlling.

Claims (1)

[Claims] A plurality of refrigeration devices, an air conditioner, a transformer that supplies power to the refrigeration device and the air conditioner, this transformer and the refrigeration device,
An electromagnetic contactor that is connected between the air conditioners and supplies and cuts off power to the refrigeration device and the air conditioner, a transformer ambient temperature measurement sensor that detects the ambient temperature of the transformer, the refrigeration device, and the air conditioner. a temperature measurement sensor that detects the temperature of the room cooled by the transformer, the current of the transformer, the detection output of the sensor for measuring the ambient temperature of the transformer, the detection output of the temperature measurement sensor, and the preset rating of the transformer. The load factor relative to the rated capacity of the transformer is determined by the capacity, rated voltage, number of phases, time constant, loss ratio, and maximum oil temperature rise.
A power supply control device for refrigeration and air conditioning, comprising a control device that calculates insulation temperature, winding temperature, and life loss to control opening and closing of the electromagnetic contactor to change the rated capacity of a transformer.