KR102436274B1 - A life assessment equipment of three phase power source circuit breakers - Google Patents

Abstract

The present invention relates to a life prediction device for a 3-phase AC power distribution circuit breaker, which is connected to the R-S phase, S-T phase and T-R phase wires of the front end of the 3-phase AC power supply line to measure the voltages of R, S, and T lines, respectively. breaker front end voltage meter; a voltage meter at the rear end of the circuit breaker connected to the R-S phase, S-T phase and T-R phase wires of the rear end of the circuit breaker to measure the voltages of R, S, and T lines, respectively; a current measuring device connected to the R-phase, S-phase, and T-phase wires of the front or rear end of the breaker of the three-phase AC power supply line to measure the current; a temperature sensor installed on the R-phase, S-phase, and T-phase wires at the rear end of the circuit breaker to measure the temperature; a microcomputer that calculates abnormal signs and remaining lifespan of each phase breaker using the data of the voltage meter at the front end of the circuit breaker, the voltage meter at the end of the circuit breaker, and the current meter by using the resistance change value of the front and rear ends of the circuit breaker, the number of times the circuit breaker is used, and the temperature data; and a display unit connected to the microcomputer.

Description

A life assessment equipment of three phase power source circuit breakers

The present invention relates to a life prediction device for a three-phase AC power distribution overall circuit breaker, and more specifically, the resistance of the circuit breaker by measuring the front voltage and the rear voltage, current and temperature of each three-phase, four-wire type power line circuit breaker at minute intervals. Predict the life of the circuit breaker by analyzing the change, temperature, and number of interruptions, and replace the circuit breaker before a power outage accident occurs. It's about predictors.

Three-phase AC power supplies power directly to large-scale customers such as factories and buildings through distribution lines by lowering the voltage of tens of thousands of volts to reduce power loss, or supplying power to small factories or general households through a pole transformer. In this way, the line loss rate is lower than that of the single-phase two-wire type, and it is strong against high temperature, steam, and dust, and the vibration is small when the motor is driven, so it is absolutely advantageous for large-capacity industrial electrical equipment.

Three-phase distribution lines are constructed in the form of overhead lines using telegraph poles in the outskirts of cities or in rural areas, but in areas where safety and aesthetics are important, such as large cities or amusement parks with many people, they are usually built in the underground way.

In a 3-phase 4-wire distribution system, the neutral (N) and power lines (R-phase, S-phase, T-phase) are combined to supply power by methods such as Y connection, delta connection, and Y-delta connection. Here, when connecting a wire to a load, it becomes 380V when one power line and another power line are connected, and when one power line and a neutral wire (N) are connected, it becomes 220V, and power is supplied to the load. Here, the neutral line (N) refers to a line in which one line of each phase is common in a polyphase multi-wire type line. This zero potential (zero potential) immediately becomes the reference potential and becomes the so-called N-phase, that is, the neutral wire.

There are switches and circuit breakers as devices that operate “ON” and “OFF” of electric lines. Switches can turn the load current ON/OFF normally, but large current that flows when the wire is short-circuited due to a fault. (Short-circuit current) cannot be turned “ON” or “OFF”. A circuit breaker blocks such a large current, and the circuit breaker is equipped with a powerful contact opening/closing mechanism and an arc extinguishing device that quickly absorbs arc energy generated when the circuit is interrupted. The contact breaker in the overall three-phase power distribution includes an automatic transfer switch that automatically changes to emergency power generation in the event of a power failure, an air circuit breaker using air insulation, and a vacuum breaker using vacuum insulation. circuit breaker), a molded circuit breaker equipped with an overcurrent trip device and an extinguishing device that operate in case of short-circuit current, etc. It is also an element that should never be neglected because once it breaks down, there are many customers and the damage is severe.

When the contact point of the circuit breaker is enlarged, there are numerous protrusions, so the surfaces of the two contact points do not contact completely. The contact resistance increases and heat is generated, leading to a power outage accident, and the automatic changeover switch also operates the generator normally at the time of scheduled selection. also do it

Researches to reduce such accidents of circuit breakers are being conducted in various fields. Among the developed technologies, in Unexamined Patent Publication No. 10-2017-0010999 "Hybrid PRA Control Method", the hybrid PRA relates to a main switch device for supplying electric power of a hybrid vehicle, one side of which is connected in series with the battery and the other side of the load ( 20) and a main switch connected in series with an electronic switch and a current sensor connected in series in parallel to connect the control unit that controls the main switch and the electronic switch through the measured value of the current sensor. It is designed for the purpose of preventing arcs that occur on the contact points when the circuit is opened.

The above technology is expected to have an effect of preventing the arc generated at the contact point of a DC power switch using a battery, but it is for a switch that connects a DC power source, and is not used for AC, and is applied to a high-voltage three-phase power supply. There is a problem that it is difficult to do.

Republic of Korea Patent Publication No. 10-2017-0010999

In order to improve the above problems, the present invention measures the 3-phase power supply circuit breaker in a live state while power is being supplied, and informs whether the circuit breaker is abnormal and the remaining lifespan to promote the stability of the power supply, and The aim was to reduce the damage.

In order to solve the above problems, the life prediction device of the three-phase power circuit breaker of the present invention is connected to the R-S phase, S-T phase and T-R phase wires of the front end of the breaker of the 3-phase AC power supply line to measure the voltages of the R, S, and T lines. a breaker front-end voltage meter 150 for measuring each; a voltage meter 180 at the rear end of the circuit breaker connected to the R-S phase, S-T phase and T-R phase wires of the rear end of the circuit breaker to measure the voltages of the R, S, and T lines, respectively; a current measuring device 200 connected to the R-phase, S-phase, and T-phase wires at the front or rear end of the three-phase AC power supply line to measure the current; a temperature sensor 250 installed on the R-phase, S-phase, and T-phase wires at the rear end of the circuit breaker to measure the temperature; Using the data of the breaker front end voltage measuring device 150, the breaker rear end voltage measuring device 180 and the current measuring device 200, the resistance change value of the front and rear ends of the breaker, the number of times the breaker is used, and the temperature data are used to show abnormal symptoms and remaining life of each phase breaker Microcomputer 300 to calculate; and a display unit 320 connected to the microcomputer 300 .

The present invention configured as described above increases the reliability of power supply by measuring the three-phase power supply circuit breaker in a live state while power is being supplied, identifying the abnormality and remaining life of the circuit breaker and replacing it in advance, thereby increasing the reliability of the three-phase electricity. It has the effect of reducing the unexpected damage caused by power outages for consumers.

1 is a circuit diagram of a three-phase power circuit breaker life prediction device according to the present invention;
2 is a block explanatory diagram of a life prediction device for a three-phase power circuit breaker according to the present invention;
3 is a circuit diagram of a three-phase power circuit breaker voltage and current meter according to the present invention;
Figure 4 is a real photo of a three-phase power circuit breaker voltage and current meter according to the present invention;
5 is a real photo of the inside of a life prediction device for a three-phase power circuit breaker according to the present invention;

The present invention relates to a life prediction device of a three-phase power circuit breaker that measures the power of a circuit breaker that supplies three-phase AC power in a live state while supplying it, and informs whether the circuit breaker has an abnormality and the remaining life.

1 is a circuit explanatory diagram of a three-phase power circuit breaker life prediction device according to the present invention, FIG. 2 is a block diagram of a three-phase power circuit breaker life prediction device according to the present invention, and FIG. 3 is a three-phase power supply according to the present invention It is a circuit diagram of a circuit breaker voltage and current measuring device, FIG. 4 is a real picture of a three-phase power breaker voltage and current measuring device according to the present invention, and FIG.

Since the resistance of the circuit breaker cannot be measured in the live state where AC electricity is supplied with a general resistance measuring instrument, the difference voltage (V) and current (I), which are the differences between the voltages before and after the circuit breaker of the three-phase wire, are measured and the circuit breaker Resistance in the live wire state can be calculated by the formula = V/I.

Since the AC voltage and current change with time, the reliability of the measured value is lowered. Therefore, the present invention program the reference time generator 330 in the microcomputer 300 of the life prediction device and set an interrupt service interval routine every 50 μs. The current and voltage values for each phase can be read within 5 μs, and when the cycle curve of each phase of AC electricity is changed due to an external influence, the measurement reference time is wrong, so the voltage synchronization signal discrimination unit composed of a program to re-establish the reference point (350) was included in the microcomputer (300).

The number of interruptions of the circuit breaker was counted using the current value, and a temperature sensor 250 was installed at the rear end of the circuit breaker, respectively, to measure the temperature change to determine abnormal symptoms.

Hereinafter, the structure of the life prediction device of the three-phase power circuit breaker according to the present invention will be described in detail with reference to FIGS. 1 to 5 .

The 3-phase AC power supply line consists of 3-wire or 4-wire conductors and is produced by an AC generator with a phase difference of 120 degrees. In principle, they are connected by forming or triangulation method. In the case of a 4-wire type, the remaining one is called an N-phase line, and the R-phase line, S-phase line, and T-phase line are connected in a Y-shape in one place and then grounded.

Voltage measurement is usually performed by connecting in parallel to the measurement object, but in Example 1 of the present invention, it is measured by connecting to R-S phase, S-T phase and T-R phase wires, and in Example 2, R-N phase, S-N phase and T-N phase wires When connected to the 220V reference power supply line and connected to the R-S phase, S-T phase and T-R phase wires, an average voltage of 380V comes out. When connected to the R-N phase, S-N phase and T-N phase wires, an average voltage of 220V is measured. do.

<Example 1>

Embodiment 1 is a three-phase power supply line consisting of only three power supply lines, and is a supply method used when power is supplied to a facility that is not related to 220V. The breaker front end voltage measuring device 150 is composed of three and is connected to the R-S phase, S-T phase and T-R phase wires of the front end of the breaker, respectively, by bolts, welding, or the like. The three elements in the lower left of the circuit diagram of FIG. 3 are the circuit diagrams of the voltage measuring device, the three blue elements in the upper part of FIG. 4 are the voltage measuring instruments, and a dotted line in the vertical direction between the three elements on the left of FIG. In the drawing, the left part of the dotted line is an analog part, and the right part of the dotted line is a digitized circuit part, so that digitized data is input to the microcomputer 300 at the upper right.

In an embodiment of the present invention, voltage and current are measured by putting a voltage measuring device and a current measuring device 200 on a single printed circuit board as shown in FIG. 4 for repeated production.

The voltage measuring device 180 at the rear end of the breaker is also composed of three and is connected to the R-S phase, S-T phase and T-R phase wires at the rear end of the breaker by bolts, welding, etc. The voltage value connected to the S-T phase is regarded as the S-phase voltage, and the voltage value connected to the T-R phase becomes the T-phase voltage.

The current measuring device 200 is usually used in series connection, but in the present invention, a current measuring device directly connected to a printed circuit board as shown in FIG. Although installed in the form of wrapping the R-phase, S-phase, and T-phase wires of The four color elements are the elements of the current meter 200, the left side of the dotted line drawn in the middle of FIG. 3 is the analog signal, the right side of the dotted line is the digital circuit part, and the digitized data is input to the microcomputer 300 on the right. was composed Although four current measuring devices are shown in FIGS. 3 and 4, only three are used in the first embodiment.

The voltage measuring device at the top of the circuit board in the lower left of FIG. 5 is used as the voltage measuring device 180 at the rear end of the breaker, and the current measuring device 200 at the bottom is not used because there is no current measurement at the rear end of the breaker.

The temperature sensor 250 is an element that detects abnormal signs and fire occurrence when the resistance value of the contact rises and the temperature rises due to Joule heat, and was installed on the R-phase, S-phase, and T-phase wires at the rear end of the circuit breaker, respectively.

Using the data of the breaker front end voltage meter 150, the breaker rear end voltage meter 180 and the current meter 200, the resistance change value of the front and rear ends of the breaker, the number of times the breaker is used, and the temperature data are used to determine the abnormal symptoms and remaining life of each phase breaker. The calculating microcomputer 300 is installed as shown in the upper right of FIG. 5, and a separate display unit 320 is connected to the microcomputer 300 to check the abnormal symptoms and remaining life of each phase breaker, It is configured to be operated by the power in the lower right of FIG. 5 .

<Example 2>

Embodiment 2 is a three-phase, four-wire power supply line consisting of four power supply lines, and is a power supply method mainly used when power is supplied to devices using 220V. The breaker front end voltage measuring device 150 is composed of three and is connected to the R-N, S-N phase and T-N phase wires of the front end of the breaker, respectively, by bolts, welding, or the like.

The three elements in the lower left of the circuit diagram of FIG. 3 are the circuit diagrams of the voltage measuring device, the three blue elements in the upper part of FIG. 4 are the voltage measuring instruments, and a dotted line is drawn between the three elements on the left in FIG. The left part of the dotted line is the analog part, and the right part of the dotted line is the digitized circuit part, and the configuration so that digitized data is input to the microcomputer 300 located at the upper right is the same as in the first embodiment.

The voltage measuring device at the rear end of the circuit breaker is also composed of three blue elements in the upper part of FIG. 4 and is connected to the R-N phase, S-N phase and T-N phase wires at the rear end of the circuit breaker by bolts, welding, etc. The voltage value connected to the R phase is the voltage value connected to the S-N phase, the voltage value connected to the S-N phase is the voltage value of the S phase, and the voltage value connected to the T-N phase is the voltage to the T phase.

As the current measuring device 200, a current measuring device 200 of a type surrounding a wire was used as shown in FIG. 4, and the R-phase, S-phase, T-phase and N-phase wires of the front end of the breaker of the 3-phase AC power supply line are installed in a way that wraps them. and may be installed at the rear end of the circuit breaker. In Example 2, unlike Example 1, all four current measuring devices 200 were used.

The upper part of FIG. 3 is a circuit diagram of the current measuring device 200, the four black elements at the lower part of FIG. 4 are the current measuring devices 200, and the left side of the dotted line drawn in the middle of FIG. 3 is an analog signal, The right side of the dotted line is a digital circuit part, and the configuration so that digitized data is input to the microcomputer 300 on the right is also the same as in Example 1.

The temperature sensor 250 is installed on the R-phase, S-phase, and T-phase wires at the rear end of the circuit breaker, but in Example 2, it is also installed on the N-phase wire.

Using the data of the breaker front end voltage meter 150, the breaker rear end voltage meter 180 and the current meter 200, the resistance change value of the front and rear ends of the breaker, the number of times the breaker is used, and the temperature data are used to determine the abnormal symptoms and remaining life of each phase breaker. The calculating microcomputer 300 is installed as shown in the upper right of FIG. 5 , and a separate display unit 320 is connected to the microcomputer to check abnormal symptoms and remaining life of each phase breaker, as shown in FIG. The point configured to be operated by the power in the lower right is the same as in the first embodiment.

In the microcomputer 300 used in Examples 1 and 2, a reference time generator 330 that finely divides time divisions for measuring voltage, current, and temperature is input into a program, and an interrupt service interval routine is set every 50 μs. It is configured so that the current and voltage values for each phase can be read within 5 μs, and the voltage and current flowing through the electric wire may change due to changes in the environment. A voltage synchronization signal determining unit 350 is required, and for this purpose, a program for discriminating and matching the voltage synchronization signal is input to the microcomputer.

The microcomputer contains a database (400) that stores information such as the appropriate resistance value by company and model for measuring the life of the circuit breaker, the resistance value at initial shipment and the resistance value after a certain period of use, and the reference value that is averaged by product current and voltage capacity. ) is connected in the form of a memory such as a hard disk, and inside the microcomputer, a pattern analysis unit 370 that analyzes a pattern of a change in resistance based on the data of the database 400, the resistance value and resistance pattern of the breaker, and the temperature , a determination unit composed of a program for predicting abnormal symptoms and lifespan based on the number of times of use, etc. is further included.

A memory unit 500 including a voltage-current-temperature storage unit 530 for storing voltage-current-temperature data and a singular state storage unit 550 for storing data of a singular state is connected to the microcomputer, and the special state and the warning state can be set by wire or wireless. A wired/wireless communication unit 600 that informs the power is provided.

The present invention configured as described above increases the reliability of power supply by measuring the three-phase power supply circuit breaker in a live state while power is being supplied, identifying the abnormality and remaining life of the circuit breaker and replacing it in advance, thereby increasing the reliability of the three-phase electricity. It has the effect of reducing the unexpected damage caused by power outages for consumers.

100: Life prediction device of a 3-phase power circuit breaker 150: Voltage measuring device at the front end of the circuit breaker
180: voltage measuring device after circuit breaker 200: current measuring device
250: temperature sensor 300: microcomputer
320: display unit 330: reference time generator
350: voltage synchronization signal determining unit 370: pattern analysis unit
390: abnormal symptom determination unit 400: database
500: memory unit 530: voltage current temperature storage unit
550: special state storage unit 600: wired and wireless communication unit
700: warning generating unit

Claims (4)

a voltage meter 150 at the front end of the breaker connected to the RS-phase, ST-phase and TR-phase wires of the three-phase AC power supply line and measuring the voltages of the R, S, and T lines, respectively;
a voltage measuring device 180 at the rear end of the circuit breaker connected to the RS-phase, ST-phase and TR-phase wires of the rear end of the circuit breaker to measure the voltages of R, S, and T lines, respectively;
a current measuring device 200 connected to the R-phase, S-phase, and T-phase wires at the front or rear end of the three-phase AC power supply line to measure the current;
a temperature sensor 250 installed on the R-phase, S-phase, and T-phase wires at the rear end of the circuit breaker to measure the temperature;
Using the data of the breaker front end voltage measuring device 150, the breaker rear end voltage measuring device 180 and the current measuring device 200, the resistance change value between the front and rear ends of the breaker, the number of times the breaker is used, and the temperature data are used to show abnormal signs and residuals of each phase breaker a microcomputer 300 for calculating the lifespan; and a display unit 320 connected to the microcomputer 300,
Input as a program to the microcomputer 300,
a reference time generator 330 for finely dividing the measurement time;
a voltage synchronization signal determining unit 350 that matches the measurement start point;
a pattern analysis unit 370 that informs a pattern of resistance change; and an abnormal symptom determination unit 390 for determining whether or not there is an abnormality. A voltage meter 150 before the breaker is connected to the RN phase, SN phase and TN phase wires of the breaker front end of the 3-phase 4-wire AC power supply line to measure the voltages of R, S, and T lines, respectively;
a voltage meter 180 at the rear end of the circuit breaker connected to the RN phase, SN phase and TN phase wires of the rear end of the circuit breaker to measure the voltages of R, S, and T lines, respectively;
a current measuring device 200 connected to the R-phase, S-phase, T-phase and N-phase wires of the front or rear end of the 3-phase 4-wire AC power supply line to measure the current, respectively;
a temperature sensor 250 installed on the R-phase, S-phase, T-phase and N-phase wires of the rear end of the circuit breaker, respectively, to measure the temperature;
Using the data of the breaker front end voltage measuring device 150, the breaker rear end voltage measuring device 180 and the current measuring device 200, the resistance change value between the front and rear ends of the breaker, the number of times the breaker is used, and the temperature data are used to show abnormal signs and residuals of each phase breaker a microcomputer 300 for calculating the lifespan; and a display unit 320 connected to the microcomputer 300,
Input as a program to the microcomputer 300,
a reference time generator 330 for finely dividing the measurement time;
a voltage synchronization signal determining unit 350 that matches the measurement start point;
a pattern analysis unit 370 that informs a pattern of resistance change; and an abnormal symptom determination unit 390 for determining whether or not there is an abnormality. delete 3. The method of any one of claims 1 or 2,
The microcomputer 300 includes a database 400 for storing information for measuring the life of the circuit breaker;
a memory unit 500 for storing voltage, current and temperature data and data of a specific state;
Wired/wireless communication unit 600 for notifying the specific state and warning state of the circuit breaker via wire or wireless; and,
A life predicting device of a three-phase power circuit breaker, characterized in that it further comprises;

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