JPH0675643A - Temperature protection method - Google Patents

Abstract

(57) [Abstract] [Object] The present invention relates to a temperature protection method for an electronic device, and avoids the system from being shut down due to a temperature sensor attached to an electronic component. A temperature obtained by adding a temperature increase (ΔTa) due to a load current to the electronic device to an installation environment temperature (Ta) of the electronic device and a temperature detected by a temperature sensor of an electronic component in the electronic device ( Tf) is detected, the temperature of the detected difference is compared with a threshold value for the difference that causes a warning message, and if the detected difference temperature is less than the threshold value, a warning message is issued. To generate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION In recent years, for example, in the field of electronic computers and the like, an uninterruptible power supply (USP) having a battery inside the device has been used.

The uninterruptible power supply (USP) is a small-to-medium-capacity power supply that replaces the conventional large-capacity fixed-voltage, fixed-frequency (CVCF) power-supply + battery, and originally protects the target device against a power failure. The purpose was to do so, and the reliability was not considered so much.

However, with the recent introduction of semiconductor elements to the uninterruptible power supply (USP), the semiconductor parts have become the main parts of the uninterruptible power supply (USP).
A temperature sensor is attached to the semiconductor element to extend the life of the semiconductor element. When such an uninterruptible power supply (USP) comes to be used in a computer system, a power failure occurs. Sometimes the device for supporting the target device detects an abnormal temperature by the temperature sensor in the semiconductor element (the abnormal temperature may occur due to an abnormality in the cooling mechanism of the uninterruptible power supply (USP)), Due to a problem other than power failure that causes the electronic computer system to go down, an effective preventive method has been required.

[0004]

2. Description of the Related Art FIG. 3 is a diagram showing a configuration example of a conventional uninterruptible power supply (USP). First, the input commercial AC 100V is converted into DC by the charger 10, but the battery 11 is charged and the next DC / A is supplied.
It is converted into alternating current by the C inverter 12 and output.

Although not shown in detail in the DC / AC inverter 12, the DC / AC inverter 12 has
By obtaining a rectangular wave AC signal with positive and negative polarities and generating a digital signal by modulating the rectangular wave AC signal by, for example, a pulse width modulation (PWM) method, and filtering the high frequency band with a filter. , AC output of a predetermined frequency is obtained.

As described above, transistors are used in the DC / AC inverter 12 as described above, and form the heart of the uninterruptible power supply (USP) 1. or,
Since the temperature rise inside the uninterruptible power supply (USP) 1 adversely affects the battery life and the life of parts such as capacitors, the uninterruptible power supply (USP) is operated for the purpose of stable operation. A temperature sensor is attached to the transistor, which is a main component of the uninterruptible power supply (USP) 1, and the fin temperature Tf of the transistor (more precisely, the junction temperature Tj of the transistor) exceeds the specified element protection temperature. When detected by the comparator 120, the DC / AC inverter 12 is stopped,
The temperature is protected.

[0007]

However, when considering from the standpoint of the user side of the uninterruptible power supply (USP) 1, the uninterruptible power supply (USP) 1 originally installed as a power failure countermeasure is, for example, Abnormality of the cooling mechanism of the uninterruptible power supply (USP), specifically, when the cooling mechanism is composed of a fan, the intake and exhaust ports are blocked (for example, dust is attached to the filter to block it). When the cooling mechanism is naturally cooled, air enters from under the uninterruptible power supply (USP) 1 and exits through the upper exhaust hole. When the exhaust hole is blocked by a foreign object}, the internal temperature rises abnormally, the temperature sensor operates, and the DC / AC inverter 12 stops without commercial power interruption. However, the power supply to the computer system on the load side is stopped and the computer system It happens that Temu will be down.

Therefore, in general, as shown in FIG.
When the temperature sensor works, an alarm is displayed and at the same time,
Some have been equipped with a mechanism for switching the output of the uninterruptible power supply (USP) 1 to commercial power, but even in this case, a momentary interruption occurs.

In view of the above-mentioned conventional drawbacks, the present invention provides a device in which a temperature sensor is attached to a main part thereof, for example, an uninterruptible power supply (USP), so that the cooling air intake / exhaust port relative to each other can be changed. An object of the present invention is to provide a temperature protection method that can detect and issue a warning message before the inverter stops to avoid an abnormal rise in temperature in the uninterruptible power supply (USP). Is.

[0010]

FIG. 1 is an explanatory view of the principle of the present invention. FIG. 1 (a) schematically shows the position of temperature measurement according to the present invention, and FIG. 1 (b) shows , Shows the relative relationship between each measured temperature and the temperature at which a warning message is generated. The above problems can be solved by the temperature protection method configured as follows.

A temperature (Ta + ΔT) obtained by adding a temperature increase (ΔTa) due to a load current to the uninterruptible power supply to an installation environment temperature (Ta) of an electronic device, for example, the uninterruptible power supply 1.
The difference between a) and the temperature (Tf) detected by the temperature sensor of the electronic component in the electronic device 1 {Tf− (Ta + ΔTa)}
Is detected and the temperature of the detected difference is compared with a threshold value (Th) for the difference that generates a warning message, and it is confirmed that the detected temperature difference is smaller than the threshold value (Th). Configure to generate a warning message when detected.

[0012]

In general, the temperature protection of main parts such as semiconductor elements is designed to operate normally even when the installation environment temperature of the device is maximum (for example, 40 ° C).

In the case of the semiconductor element, the temperature rating (T
jmax) is specified. Tjmax> Tj = θ _jf × Pd + ΔTa + Ta where θ _jf : Thermal resistance between the semiconductor junction and the radiation fin Pd: Power consumption of the semiconductor element ΔTa: Temperature rise inside the device, which is proportional to the load current in the device Ta : Installation environment temperature of device Tj: Junction temperature of electronic element (transistor)

As a method of generating a warning message before the DC / AC inverter of the uninterruptible power supply (USP) is stopped by the temperature sensor attached to the semiconductor element, the temperature detection level is set to binary and the warning is issued. However, in order to detect the binary value within Tjmax, it is necessary to increase the temperature margin, resulting in an increase in the size of the radiation fin and an increase in cost.

Further, the temperature rating (T
As is clear from the equation indicating (jmax), if the installation environment temperature Ta of the device is low, detection by the temperature sensor becomes difficult.
Therefore, in the present invention, even if the installation environment temperature Ta of the uninterruptible power supply (USP) is low, the installation temperature Ta of the uninterruptible power supply (USP) and The load state (load current I ₀ ) of the uninterruptible power supply (USP) is measured, and in the uninterruptible power supply (USP),
A temperature increase ΔTa due to a closed state of the cooling intake / exhaust port, and the addition of the ΔTa to the installation environment temperature Ta;
Originally, the temperature T of the radiation fin of the semiconductor element provided
f (Tj−θ _jf × Pd) and the difference {Fig. 1
The warning message is generated when the shaded and vertical lines in (b)} are smaller than a predetermined threshold value.

Therefore, in the uninterruptible power supply (USP),
There is an effect that a warning message can be generated economically and easily before stopping the DC / AC inverter.

[0017]

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a diagram for explaining the principle of the present invention, and FIG. 2 is a diagram showing an embodiment of the present invention.

In the present invention, the temperature obtained by adding the temperature increase (ΔTa) due to the load current (I ₀ ) to the electronic device to the installation environment temperature (Ta) of the electronic device, and the electronic parts in the electronic device. Means for detecting a difference from the temperature (Tf) detected by the temperature sensor and comparing the detected difference temperature with a threshold value (Th) for the difference generating the warning message,
It is a necessary means for carrying out the present invention. The same reference numerals indicate the same objects throughout the drawings.

The temperature protection method of the present invention will be described below with reference to FIG. 2 while referring to FIG. First, it is assumed that the temperature rise in a device, for example, the uninterruptible power supply (USP) 1, is defined by the load current input to the uninterruptible power supply (USP) 1. The load current I ₀ input to 1 is taken out, rectified and converted into a DC voltage to obtain a voltage ΔVa corresponding to the temperature increase ΔTa.

On the other hand, the installation environment temperature Ta where the uninterruptible power supply (USP) 1 is installed is detected by a temperature sensor, and a voltage Va corresponding to the environment temperature Ta is obtained. Then, the temperature sensor originally attached to, for example, the transistor of the DC / AC inverter 12 of the uninterruptible power supply (USP) 1 detects the temperature Tf of the heat radiation fin of the transistor to detect the temperature of the heat radiation fin. A voltage Vf corresponding to Tf is obtained.

The voltage Va and ΔVa are added by the adder 13, and the adder / subtractor 14 provided in the next stage adds the voltage V
The difference between f and (Va + ΔVa) is calculated. Since the difference corresponds to the shaded and vertical lines in FIG. 1 (b), the predetermined threshold (Th) necessary to generate the warning message,
The comparator 15 performs comparison, and when a temperature difference equal to or lower than the threshold value (Th) is detected, a warning message is generated.

When the installation environment temperature of the uninterruptible power supply (USP) 1 becomes low, the temperature of the difference also becomes large, and the threshold (Th)
Although it is not a condition for generating a warning message even if compared with, the device environmental temperature is, for example, 40 ° C.
When the temperature difference reaches the maximum temperature, the shaded temperature difference decreases, and when a temperature difference below the threshold value is detected due to the temperature rise due to the load current I ₀ , a warning message can be issued immediately.

Since the detected temperature at this time is lower than the temperature Tf of the radiation fin of the semiconductor element, the DC / A
A warning message can be generated before the C inverter 12 is stopped, and the blocking of the cooling intake and exhaust ports of the uninterruptible power supply (USP) 1 can be removed in a timely manner so that the DC / AC inverter 12 It is possible to prevent the power supply from being stopped and to stably operate the electronic computer system using the uninterruptible power supply (USP) 1.

In the above-mentioned embodiment, the uninterruptible power supply (USP) 1 is described as an example of the device to be protected by temperature, but the device is not limited to this, and electronic parts such as semiconductor elements are used. , A device configured to attach a temperature sensor to the electronic component, detect an abnormality in temperature, and stop the operation of the electronic circuit. When the temperature rises due to blocking of the intake and exhaust ports for cooling, Obviously, it can be applied when it is desired that the operation of the electronic circuit is not stopped.

[0025]

As described above in detail, according to the temperature protection circuit of the present invention, before the apparatus is stopped by the temperature sensor attached to the electronic parts in the apparatus and the whole system goes down. By generating the warning message, the factor of the temperature rise in the device can be removed,
The effect is that the entire system can be operated stably.

[Brief description of drawings]

FIG. 1 is an explanatory view of the principle of the present invention.

FIG. 2 is a diagram showing an embodiment of the present invention.

FIG. 3 is a diagram showing a configuration example of a conventional uninterruptible power supply (USP).

[Explanation of symbols]

1 Uninterruptible power supply (USP) or device 10 Charger 11 Battery 12 DC / AC inverter 13 Adder 14 Adder / subtractor 15 Comparator 120 Comparator Ta Installation environment temperature ΔTa Temperature rise in the device Tf Heat dissipation of semiconductor element Fin temperature Pd Power consumption of semiconductor device I ₀ Load current in equipment

Claims (1)

[Claims] 1. The installation environment temperature (Ta) of the electronic device (1),
Temperature rise due to load current to the electronic device (1) (ΔT
The difference between the temperature to which a) is added and the temperature (Tf) detected by the temperature sensor of the electronic component in the electronic device (1) is detected, and the temperature of the detected difference and a warning message are generated. A temperature protection method comprising: comparing a threshold value (Th) with respect to a difference and generating a warning message when detecting that the temperature of the detected difference is smaller than the threshold value (Th).