JPH06141460A - Protective relay device - Google Patents

Abstract

PURPOSE:To provide a protective relay device wherein a circuit breaker can be opened surely before an electric apparatus to be protected exceeds a permissible temperature. CONSTITUTION:When the supply of an electric current to an elect apparatus is started, an apparatus temperature is initialized on the basis of an ambient temperature or of whether solar insulation exists or not (Step 100), and, after that, an apparatus temperature after a prescribed time is estimated at every prescribed time from an electric current supplied to the electric apparatus, from the ambient temperature or from whether the solar insulation exist or not (Step 110 to Step 140). When the estimated apparatus temperature becomes a permissible temperature K or higher, a circuit breaker is opened, and the supply of the electric current to the electric apparatus is stopped (Step 150, Step 170). As a result, the circuit breaker can be opened surely before the apparatus temperature reaches the permissible temperature K, and it is possible to prevent that a stress is given to the electric apparatus.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a protective relay device for preventing an abnormal temperature rise of electric equipment due to energization.

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Patent Publication No. 3-68616.
As disclosed in Japanese Patent Publication, the allowable duration for which electric equipment can be energized is set by the current-time characteristic peculiar to the electric equipment, and when the energization time to the electric equipment exceeds this allowable duration, Abnormal temperature due to overload of electric equipment by opening the circuit breaker to stop energizing the electric equipment and changing the current-time characteristics that set the allowable duration of the electric equipment depending on the temperature of the electric equipment and its ambient temperature. There is known a protective relay device capable of surely preventing rising and burnout of equipment.

[0003]

However, such a conventional protective relay device outputs an opening command to the circuit breaker when the energization time of the electric equipment exceeds the allowable continuation time, and therefore, when the circuit breaker is opened, the electric power is turned off. The temperature of the equipment will exceed the allowable temperature, which will stress electrical equipment. In addition, it takes time for the circuit breaker to actually open, the current flow is cut off, and then the heat is dissipated and the electrical equipment cools below the allowable temperature after the open command is output to the circuit breaker.
During that time, electrical equipment will continue to be stressed. The increase in the temperature of the electric device per unit time increases as the energizing current at that time increases. Therefore, the larger the energizing current when the breaker is opened, the greater the stress on the electric device.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a protective relay device capable of surely opening a circuit breaker before electric equipment exceeds an allowable temperature.

[0005]

A protective relay device of the present invention, which has been made to achieve the above object, has a circuit breaker provided in a main circuit for supplying electric power to an electric device, as shown in FIG. Energizing current detecting means for detecting an energizing current from the main circuit to the electric device, ambient condition detecting means for detecting a condition of the electric device surrounding that affects the temperature of the electric device, and at each predetermined time, each of the above Based on the detection result of the detection means, a device temperature estimation means for estimating the temperature of the electric equipment after a predetermined time from the present time, and the estimation result of the temperature of the electric equipment by the equipment temperature estimation means is equal to or higher than a preset allowable temperature. If the estimated result is equal to or higher than the allowable temperature, an opening command is output to the circuit breaker to open the circuit breaker.

[0006]

In the protective relay device of the present invention configured as described above, the energizing current detecting means detects the energizing current from the main circuit to the electric equipment, and the ambient state detecting means detects the temperature of the electric equipment. The state of the surroundings of the electric device that has an influence (for example, ambient temperature, solar radiation, etc.) is detected. Further, the device temperature estimation means, the detection result by each of these detection means, every predetermined time,
That is, the temperature of the electric device after a predetermined time from the present time is estimated based on the current flowing through the electric device and the surrounding state. Then, the judging means judges whether or not the estimated temperature of the electric device is equal to or higher than a preset allowable temperature, and if the temperature is equal to or higher than the allowable temperature, an open command is output to the breaker to break the breaker. To release.

That is, since the temperature rise per unit time of the electric equipment can be obtained from the energizing current of the electric equipment and the ambient condition such as the ambient temperature, in the protective relay device of the present invention, every predetermined time. In addition, the temperature of the temperature device after a predetermined time from the current time is sequentially estimated from the energizing current of the electric device and the surrounding state, and the breaker is opened when the estimated result exceeds the allowable temperature. .

[0008]

Embodiments of the present invention will be described below with reference to the drawings. First, FIG. 2 is a schematic configuration diagram showing the configuration of the protective relay device of the embodiment. As shown in FIG. 2, the protective relay device according to the present embodiment is provided in a circuit breaker 10 provided in a main circuit 4 for supplying power to the electric device 2 and a power supply path from the circuit breaker 10 to the electric device 2. Current transformer 1 for extracting a secondary current corresponding to a current flowing from main circuit 4 to electric device 2
2, a current detector 14 as an energizing current detecting means for detecting an energizing current of the electric device 2 from the secondary current taken out by the current transformer 12, and an ambient state detecting means for detecting an ambient temperature of the electric device 2. The temperature of the electric device 2 (hereinafter referred to as the device temperature) is estimated based on the detection signals from the temperature sensor 16, the current detector 14, and the temperature sensor 16, and the cutoff is performed when the estimated device temperature exceeds the allowable temperature K. Bowl 1
And a control device 18 for releasing 0. The electric device 2 of this embodiment is an electric device installed outdoors, such as a trolley wire for supplying power to a train.

The control device 18 includes a CPU, a ROM, and a ROM.
When the main circuit 4 is supplying electric power to the electric device 2, the main circuit 4 operates by receiving an energization signal indicating that fact. That is, the control device 18 executes the control process shown in FIG. 3 when the main circuit 4 starts feeding power to the electric device 2. Hereinafter, this control process will be described in detail.

As shown in FIG. 3, when the control process is started by the main circuit 4 starting to supply power to the electric device 2, first, at step 100, the present device temperature is initialized. The initial setting of the device temperature is to first read the ambient temperature of the electric device 2 detected by the temperature sensor 16, and then read the sunrise / sunset data and the current date and time stored in advance in the ROM. It is executed by a procedure of determining whether or not the electric device 2 is currently receiving solar radiation, and calculating the device temperature from the determination result (that is, presence / absence of solar radiation) and the ambient temperature.

As described above, when the device temperature is initialized in step 100, the process proceeds to step 110, the energizing current of the electric device 2 detected by the current detector 14 is read, and the process proceeds to step 120. Then, the ambient temperature of the electric device 2 detected by the temperature sensor 16 is read.

Then, in the following step 130, based on the read energizing current and the ambient temperature of the electric device 2,
Using a preset map, the amount of change in temperature of the electric device 2 that occurs from the present time to the elapse of a predetermined time (for example, 200 msec.) Is calculated. Two types of maps are preset for this temperature change amount calculation map depending on the presence or absence of solar radiation. When calculating the temperature change amount in step 130, the current date is calculated as described above. And the time and the presence / absence of solar radiation are determined to select the map.

When the amount of change in temperature of the electric device 2 is calculated in this way, the process proceeds to the subsequent step 140, and immediately after the control process is started, the device temperature initially set in step 100 is read, and the reverse operation is performed. If the step 140 is already executed after the control process is started, the device temperature previously calculated in the step 140 is read, and the read device temperature is set in the step 13
By adding the temperature change amount calculated by 0, the device temperature after a predetermined time (for example, 200 msec.) Is estimated.

Then, in the following step 150, it is determined whether or not the estimated device temperature after a predetermined time (hereinafter referred to as the estimated temperature) is equal to or higher than a preset allowable temperature K, and the estimated temperature is determined. If is not equal to or higher than the allowable temperature K, the process proceeds to the following step 160, and after the process of step 110 is started last time, a predetermined time (for example, 200
msec.) It is determined whether a predetermined time has elapsed by determining whether or not the time has elapsed, and when the predetermined time has elapsed, the process proceeds to step 110 again. By the processing of step 160, the estimated temperature is calculated every predetermined time (for example, 200 msec.) By the processing of steps 110 to 140.

On the other hand, if it is determined in step 150 that the estimated temperature has exceeded the allowable temperature K, step 170
Then, an opening command for the circuit breaker 10 is output to open the circuit breaker 10. Then, in the following step 180, an alarm indicating an abnormality of the electric device 2 is output, and the process ends.

As described above, in the protective relay device of this embodiment, the device temperature after a predetermined time from the present time is determined based on the current flowing through the electric device 2, the ambient temperature, and the presence or absence of solar radiation at every predetermined time. Are sequentially estimated, and the breaker 10 is opened when the estimated temperature exceeds the allowable temperature. Therefore, the circuit breaker 10 can be opened before the device temperature exceeds the allowable temperature K, and it is possible to prevent stress on the electric device.

Further, when the energizing current is large, the temperature rise per unit time is larger than when the energizing current is small, so the actual device temperature when the circuit breaker 10 is open is the energizing current. The lower it gets. Therefore, when the energization current is large, even if the electric device 2 is energized until the circuit breaker 10 is actually opened after the open command is output to the circuit breaker 10 and the device temperature rises, the device temperature is allowed. It does not exceed the temperature.

In the present embodiment, steps 110 to 110 executed to estimate the device temperature at every predetermined time.
The processing of step 140 and step 160 corresponds to the device temperature estimating means of the present invention, determines whether the estimated temperature is equal to or higher than the allowable temperature K, and opens the circuit breaker 10 when the estimated temperature is equal to or higher than the allowable temperature K. 150 and step 17
The processing of 0 corresponds to the determination means of the present invention.

Here, in the above embodiment, the current detector 14
And the temperature of the electric device 2 actually detected by the temperature sensor 16 and the ambient temperature, and the presence or absence of solar radiation obtained from the current date and time is used to estimate the device temperature after a predetermined time. However, for example, a solar radiation sensor that detects the solar radiation angle or the solar radiation intensity with respect to the electric device 2, the electric device 2
An electric device 2 such as an air volume sensor that detects the strength of wind hitting the wind
It is possible to estimate the device temperature more accurately by adding a sensor that detects various weather conditions that affect the temperature of the device and estimating the device temperature by adding the detection signal from the sensor. become.

Further, if the arithmetic expression and the map used for estimating the device temperature are set in consideration of the installation condition as well as the characteristic peculiar to the electric device 2, the estimation accuracy of the device temperature is further improved. can do. Next, in the above embodiment, when the estimated device temperature becomes equal to or higher than the allowable temperature K, the circuit breaker 10 is opened and an alarm indicating that is output. However, for example, the circuit breaker 10 is opened. After that, the energization current is set to "0" and the estimation of the device temperature is continued. When the estimated temperature becomes equal to or lower than a predetermined return temperature lower than the allowable temperature K, the circuit breaker 10 is closed and the electric device 2 The energization may be restarted.

[0021]

As described above, in the protective relay device of the present invention, the device temperature after a predetermined time from the present time is sequentially estimated from the current flowing through the electric device and the surrounding conditions at every predetermined time. However, since the circuit breaker is configured to open when the estimated result exceeds the allowable temperature, the circuit breaker can be opened before the device temperature exceeds the allowable temperature, resulting in stress on electrical equipment. Can be given.

When the energizing current is large, the temperature rise per unit time is larger than when the energizing current is small. Therefore, the actual device temperature when the circuit breaker is opened becomes larger as the energizing current increases. Get lower. For this reason, when the energizing current is large, even if the electric device is energized until the circuit breaker actually opens after the open command is output to the circuit breaker and the device temperature rises, the device temperature exceeds the allowable temperature. There is no such thing.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating a configuration of the present invention.

FIG. 2 is a schematic configuration diagram illustrating a configuration of a protective relay device according to an embodiment.

FIG. 3 is a flowchart showing a control process executed in the control device of the embodiment.

[Explanation of symbols]

2 ... Electrical equipment 4 ... Main circuit 10 ... Breaker 1
2 ... Current transformer 14 ... Current detector 16 ... Temperature sensor 18 ... Control device

Claims (1)

[Claims] 1. A circuit breaker provided in a main circuit for supplying electric power to an electric device, an energizing current detecting means for detecting an energizing current from the main circuit to the electric device, and a temperature of the electric device. Ambient condition detecting means for detecting a state around the electric equipment; and equipment temperature estimating means for estimating the temperature of the electric equipment after a predetermined time from the present time, based on the detection result of each detecting means at every predetermined time, It is determined whether or not the estimation result of the temperature of the electric device by the device temperature estimation means is equal to or higher than a preset allowable temperature, and if the estimation result is equal to or higher than the allowable temperature, an open command is output to the circuit breaker. A protective relay device, comprising: a determination means for opening the breaker.