JP5279230B2 - Electronic circuit breaker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To lessen an error in measurement of electric energy by detecting the peripheral temperature of an AD converter and correcting an AD converted value in an electric circuit breaker; and to lower the cost of an electronic circuit breaker more than to use an expensive AD converter. <P>SOLUTION: The electronic circuit breaker 1 includes: a tripping circuit 2; a current detector 3; a voltage detector 4; an AD converter 61, which converts current information and voltage information into AD converted values; an error corrector 62, which corrects the converted information; a processor 63; a display 8; and a temperature detector 7, which detects the peripheral temperature of the AD converter 61. Since the error corrector 62 corrects the error of the AD converted value, based on the peripheral temperature of the AD converter 61 detected with the temperature detector 7, it can lessen the error in measurement of the electric energy. Moreover, it can correct the error caused by the temperature of the AD converted value merely by adding the temperature detector 7 and the error corrector 62 to the constitution of a conventional electronic circuit breaker 1, so it becomes low-cost with simple constitution. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to an electronic circuit breaker that trips an electric circuit based on current information and voltage information of the electric circuit.

  One configuration of a conventional electronic circuit breaker is shown in FIG. The electronic circuit breaker 101 includes a contact 113 that is arranged in the electric circuit 111 and connects the external power source 112 and the electronic circuit breaker 101, a trip circuit unit 102 that trips the electric circuit 111 by the contact 113, and a current flowing through the electric circuit 111. A current detection unit 103 to detect, a voltage detection unit 104 to detect the voltage of the electric circuit 111, an AD converter that acquires current information and voltage information from the current detection unit 103 and the voltage detection unit 104, converts them into digital signals, and outputs them Unit 161, processing unit 163 that outputs a trip signal to trip circuit unit 102 based on current information and voltage information from AD converter unit 161, power supply circuit 105 that supplies power to processing unit 163, and the like, And a display unit 108 for displaying information and the like.

  The current detection unit 103 detects the current in the electric circuit 111 and outputs current information It, Is, and Ir to the AD converter 161. The voltage detector 104 detects the voltage of the electric circuit 111 and outputs voltage information Vst and Vrs to the AD converter 161. The AD converter 161 digitally converts the acquired current information and voltage information and outputs the digital information to the processing unit 163. The processing unit 163 determines an abnormality such as a short circuit, an overcurrent, an over / under voltage based on the acquired information, If it is determined, a trip signal is output to the trip circuit unit 102 and the electric circuit 111 is tripped. The processing unit 163 also calculates power from the acquired current information and voltage information, and outputs the power information, current information, abnormality information, and the like to the display unit 108 via RS485, Ethernet, and the like. The display unit 108 displays information acquired by an LED or liquid crystal.

  FIG. 7 shows the current detection performance required for the electronic circuit breaker 101. The horizontal axis indicates the magnitude of the current, and the vertical axis indicates the tripping operation time. Current detection needs to detect two types of short-circuit area and over-current area. In the short-circuit area, it must be tripped within a certain period of time. In the over-current area, the trip time depends on the over-current level. Must be removed. Further, in voltage detection, there are conditions for overvoltage and undervoltage, and the time required for tripping differs depending on the voltage level. The processing unit 163 outputs a trip signal based on the current and voltage conditions.

  In such an electronic circuit breaker, with an electronic circuit breaker that does not measure power, an accuracy of about ± 10% with respect to the rated current is sufficient even at the time of overcurrent detection that requires the highest detection accuracy. However, when performing power measurement, the error is ± 2.5% or less for the invalid class, ± 2% or less for the normal class, and ± 1. High accuracy of 0% or less is required.

  Therefore, an error in the AD conversion value converted into a digital signal by the AD converter 161 becomes a problem. For example, when a low-cost 10-bit AD converter is used, generally the absolute error of the AD converter is ± 3 LSB or less, or ± 5 LSB or less. When the absolute error is ± 5 LSB, the error is about ± 0.5% (= 5/1024 * 100 [%]). If the error of the circuit block or the error due to the calculation is taken into consideration in this error, the accuracy required for the wattmeter cannot be satisfied. If a high-performance AD converter with a large number of bits is used for the electronic circuit breaker, the error is reduced but the cost is increased.

  There is also known an error correction device that corrects an error of the above-described AD converter by a microcomputer (for example, see Patent Document 1).

However, if an error correction device as shown in Patent Document 1 is used for an electronic circuit breaker, a correction circuit must be configured by a microcomputer or the like, resulting in high costs.
JP 2001-339307 A

  The present invention solves the above problem, and detects the ambient temperature of the AD converter and corrects the AD conversion value, thereby reducing the measurement error of the electric energy at a lower cost than using an expensive AD converter. The purpose is to provide a circuit breaker.

In order to achieve the above object, the invention of claim 1 includes a tripping circuit unit for tripping an electric circuit, a current detection unit for detecting a current flowing in the electric circuit, a voltage detection unit for detecting a voltage of the electric circuit, and the current detection. An AD converter that converts current information and voltage information detected by the voltage detection unit and the voltage detection unit into a digital signal, and tripping to the trip circuit unit based on the current information or voltage information converted into a digital signal by the AD converter a processing section for outputting a signal in electronic breaker and a temperature detector for detecting the ambient temperature of the AD converter, the converted by the AD converter based on the ambient temperature detected by said temperature detecting portion An error correction unit that corrects at least one of the current information and voltage information, and when the electronic circuit breaker is powered on or around the AD converter Degree is and a relation table between the integrated value of electric energy and the AD converter of ambient temperature flowing through the path at the time of the start when the estimated normal temperature, ambient temperature of the AD converter, the path The temperature rises in proportion to the increase of the integrated value from the reference time of the flowing electric energy, and the temperature detection unit uses the start time as the reference time of integration, and the integrated value of the electric energy calculated from the current information and voltage information And the current ambient temperature of the AD converter determined from the relation table is output as the detected temperature.

The invention according to claim 2 is detected by a trip circuit unit for tripping an electric circuit, a current detection unit for detecting a current flowing through the electric circuit, a voltage detection unit for detecting a voltage of the electric circuit, and the current detection unit and the voltage detection unit. An AD converter that converts the current information and voltage information into a digital signal; and a processing unit that outputs a trip signal to the trip circuit unit based on the current information or voltage information converted into a digital signal by the AD converter; In the electronic circuit breaker, the temperature detection unit for detecting the ambient temperature of the AD converter, and the current information and the voltage information converted by the AD converter based on the ambient temperature detected by the temperature detection unit of the error correction unit for correcting at least one, of the AD converter temperature when the integrated value and the integrated value of the amount of power flowing through the path in a unit time Temperature, and a relationship table between descending values, the ambient temperature of the AD converter, raised or lowered in accordance with the accumulated value of electric energy per unit time flowing through the path, the temperature detection unit is shut off electronic The integrated value of the amount of electric power within the unit time is obtained from the current information and voltage information, starting from when the power of the device is turned on or when the ambient temperature of the AD converter is estimated to be normal temperature, and AD is obtained from the relation table. The current ambient temperature of the AD converter determined by determining the rise or fall value of the ambient temperature of the converter and adding the rise or fall value of the determined ambient temperature per unit time with the ambient temperature at the start as a reference Is output as the detected temperature.

A third aspect of the invention is the electronic circuit breaker according to the first or second aspect , further comprising a power supply device that operates at least the temperature detection unit and the processing unit when the electric circuit is tripped.

According to a fourth aspect of the present invention, in the electronic circuit breaker according to the third aspect of the present invention, at least one of the temperature detection unit and the processing unit extends an operation cycle when the electric circuit is tripped.

A fifth aspect of the present invention is the electronic circuit breaker according to the first or second aspect , further comprising a non-volatile storage unit and a time information acquisition unit that acquires time, wherein the storage unit is configured to perform the integration. The value and the time information acquired by the time information acquisition unit are stored.

According to a sixth aspect of the present invention, in the electronic circuit breaker according to the fifth aspect , the processing unit stores the detected temperature immediately before the current information and the voltage information satisfy an electric circuit tripping condition in the storage unit. Write.

According to the present invention, the error correction unit, so to correct an error of the AD conversion value based on the ambient temperature of the AD converter detected by the temperature detecting unit, it is possible to reduce the measurement error of electric energy . Further, the error due to the temperature of the AD conversion value can be corrected only by adding the temperature detection unit and the error correction unit to the conventional configuration, and the configuration is simple and the cost is low. Further, since the temperature is estimated from the current information and the power information without using the temperature sensor, the temperature sensor becomes unnecessary and the electronic circuit breaker can be reduced in cost.

According to the invention of claim 2 , since the error correction unit corrects the error of the AD conversion value based on the ambient temperature of the AD converter detected by the temperature detection unit, it is possible to reduce the measurement error of the electric energy. Further, the error due to the temperature of the AD conversion value can be corrected only by adding the temperature detection unit and the error correction unit to the conventional configuration, and the configuration is simple and the cost is low. Further , since the temperature rise and fall are estimated based on the integrated values of current information and power information within a predetermined time, the accuracy of the estimated temperature is improved. Thereby, the error caused by the temperature of the AD conversion value can be corrected, and the measurement error of the electric energy can be reduced.

According to the invention of claim 3 it can also operate the processing unit and the temperature detecting section when the path is tripped, to estimate the ambient temperature of the AD converter when the temperature is lowered by heat radiation. Thus, since the operation resumption of the electronic circuit breaker can also be estimated ambient temperature of AD converter, that by correcting the error caused by the temperature of the AD conversion value, to reduce the measurement error of electric energy Can do.

According to invention of Claim 4 , since the power consumption of a temperature detection part and a process part becomes small, the power supply capacity | capacitance of a power supply device can be made small, and an electronic circuit breaker can be made low-cost.

According to the invention of claim 5 , since the integrated value of current or power and the time information before being removed are stored even when the electric circuit is disconnected, the electric circuit is closed and the electronic circuit breaker operates. when recover, tripped estimates the temperature of the immediately preceding are, and the estimated temperature and the trip time to estimate the decrease in temperature from the time of recovery, the ambient temperature of the AD converter of the recovery from the estimated Can be estimated. Thereby, the error caused by the temperature of the AD conversion value can be corrected, and the measurement error of the electric energy can be reduced.

According to the sixth aspect of the present invention, since the integrated value and time information of the current or power immediately before the electric circuit is removed are stored, the same effect as in the fifth aspect can be obtained. In addition, since the number of times of writing to the storage unit is smaller than that of the electronic circuit breaker according to the fifth aspect , the life of the storage unit is prolonged, and the effort for updating the storage unit is reduced.

(First embodiment)
An electronic circuit breaker according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows the configuration of an electronic circuit breaker. The electronic circuit breaker 1 is arranged on the electric circuit 11 and connects the external power source 12 and the electronic circuit breaker 1, the trip circuit part 2 that trips the electric circuit 11 by the contact 13, and the current flowing through the electric circuit 11. A current detection unit 3 for detecting, a voltage detection unit 4 for detecting the voltage of the electric circuit, and a power supply circuit 5 for supplying power to the current detection unit 3, the voltage detection unit 4 and the like are provided. Further, the electronic circuit breaker 1 acquires the current information and voltage information detected by the current detection unit 3 and the voltage detection unit 4, converts them into digital signals, and outputs them, and the ambient temperature of the AD converter 61. Based on the detected temperature detection unit 7, the error correction unit 62 that corrects the digital signal output from the AD converter 61, and the corrected current information and voltage information, a trip signal is output to the trip circuit unit 2. A processing unit 63 that outputs energization information and a display unit 8 that displays the energization information are provided. The AD converter 61, the error correction unit 62, and the processing unit 63 constitute the arithmetic circuit 6.

  The electronic circuit breaker 1 is a three-phase power distribution system, and the power supply circuit 5 includes, for example, two sets of wires T, S, and R between the wires R-S and wires S-T among the wires T, S, R of the electric circuit 11. A drive power supply is created based on the line voltage. The current detection unit 3 detects current with a current transformer 31 arranged in the wirings T, S, and R of the electric circuit 11 and outputs current information It, Is, and Ir to the AD converter 61. The voltage detection unit 4 detects the line voltage between the wirings ST and the wiring RS of the electric circuit 11 and outputs voltage information Vst and Vrs to the AD converter 61. The AD converter 61 outputs an AD conversion value obtained by converting the acquired current information and voltage information into a digital signal. The temperature detector 7 has a temperature sensor.

  The error correction unit 62 corrects the AD conversion values of the current information and the voltage information acquired from the AD converter 61 based on the temperature detected by the temperature detection unit 7 and outputs the corrected value to the processing unit 63. The processing unit 63 determines an energization abnormality such as a short circuit or overcurrent based on the acquired current information and voltage information, and outputs a trip signal to the trip circuit unit 2. When receiving the trip signal from the processing unit 63, the trip circuit unit 2 opens the contact 13 and trips the electric circuit 11. The processing unit 63 also calculates power information based on the current information and the voltage information, and outputs the current information, power information, energization abnormality, and the like to the display unit 8 via RS485, Ethernet, or the like. The display unit 8 includes an LED, a liquid crystal, and the like, and displays acquired information.

  The operation of the electronic circuit breaker 1 configured as described above will be described. The current detection unit 3 detects the current in the electric circuit 11 and outputs current information to the AD converter 61, and the voltage detection unit 4 detects the line voltage of the electric circuit 11 and outputs the voltage information to the AD converter 61. The AD converter 61 converts the acquired current information and voltage information into an AD conversion value of a digital signal and outputs it to the error correction unit 62. Further, the temperature detection unit 7 detects the temperature around the AD converter 61 with a temperature sensor and outputs the detected temperature to the error correction unit 62. The error correction unit 62 corrects the AD conversion values of the current information and the voltage information acquired from the AD converter 61 based on the temperature detected by the temperature detection unit 7 and outputs the corrected value to the processing unit 63. The acquired processing unit 63 calculates power information based on the current information and the voltage information, and displays current information, power information, and energization information such as energization abnormality on the display unit 8. The processing unit 63 also determines an energization abnormality based on the current information and the voltage information, and outputs a trip signal to the trip circuit unit 2 if it is determined to be abnormal.

  Next, correction of the error of the AD conversion value performed by the error correction unit 62 will be described with reference to FIG. FIG. 2 shows an example of absolute accuracy of AD conversion of the AD converter. This AD converter has, for example, 10 bits and an input voltage of 0 to 5V. The horizontal axis represents the AD conversion value, and the vertical axis represents the error of the AD conversion value in LSB. A solid line A in the figure indicates an error when the ambient temperature of the AD converter is 25 ° C., and a dotted line B indicates an error when the ambient temperature is 85 ° C. The higher the temperature, the larger the error of the AD conversion value.

  When the ambient temperature of the AD converter is 85 ° C., if the input voltage is 5 V, the AD conversion value 1024 is output originally, but the AD conversion value 1023 lower by 1 LSB is output. Then, 5 (V) × 1023/1024 = 4.995 (V), and it is mistaken that a voltage 5 mV lower is input. Accordingly, when the AD correction value 1023 is acquired from the AD converter at 85 ° C., the error correction unit performs correction by adding 1LSB.

  The error correction unit 62 stores an error amount for each AD conversion value at each temperature of the AD converter 61, and corrects the error of the AD conversion value based on the temperature detected by the temperature detection unit 7 as described above. Do. Further, the error correction unit 62 may store a relational expression between the temperature, the AD conversion value, and the error, calculate an error amount from the relational expression, and perform correction. As described above, the error correction unit 62 stores or calculates an error amount for each AD conversion value at each temperature, and calculates an error of the AD conversion value based on the ambient temperature of the AD converter 61 detected by the temperature detection unit 7. Since the correction is made, the measurement error of the electric energy can be reduced. In addition, the error due to the temperature of the AD conversion value can be corrected simply by adding the temperature detection unit 7 and the error correction unit 62 to the configuration of the conventional electronic circuit breaker. It becomes.

(Second Embodiment)
An electronic circuit breaker according to a second embodiment of the present invention will be described with reference to FIG. In FIG. 3, the same components as those of the electronic circuit breaker in FIG. The electronic circuit breaker 1 of this embodiment includes a temperature detection unit 7 having a temperature estimation unit 71. The temperature estimation unit 71 estimates the ambient temperature of the AD converter 61 from the integrated value of the electric power of the electric path 11.

  Operation | movement of the electronic circuit breaker 1 comprised in this way is demonstrated. The processing unit 63 calculates power from the current information and voltage information, and outputs the calculated power to the temperature estimation unit 71. The temperature estimation unit 71 integrates the acquired power, estimates the ambient temperature of the AD converter 61 from the integrated value, and outputs it to the error correction unit 62. Table 1 below shows the estimated temperature around the AD converter 61 for each integrated value of electric energy. The integrated value of the electric energy is represented by an index with a predetermined electric energy as 1. Then, for example, when the electronic circuit breaker 1 is turned on or when the ambient temperature of the AD converter 61 is estimated to be normal temperature, the temperature estimation unit 71 performs integration of electric energy, The ambient temperature of the AD converter 61 is estimated from Table 1 and output to the error correction unit 62. The error correction unit 62 corrects the AD conversion value from the acquired temperature as in the first embodiment. Further, the ambient temperature of the AD converter 61 may be estimated from the integrated value of the current. As described above, since the ambient temperature of the AD converter 61 is estimated from current information and power information without using the temperature sensor, the temperature sensor becomes unnecessary, and the electronic circuit breaker 1 can be reduced in cost.

  Next, a modification of the electronic circuit breaker according to the second embodiment will be described. The electronic circuit breaker 1 of the present modification is different from the second embodiment in the temperature estimation method in the temperature estimation unit 71. The temperature estimation unit 71 estimates the temperature fluctuation amount of the temperature rise or temperature fall within the time from the integrated value of the electric energy within the unit time, and adds the estimated temperature fluctuation amount to the temperature at the reference time. Thus, the ambient temperature of the AD converter 61 is estimated.

  Table 2 below shows an estimated value of temperature rise or temperature fall for each integrated value of electric energy within a unit time. The unit time is, for example, 1 minute, and the integrated value of the electric energy is represented by an index with a predetermined electric energy as 1. Then, for example, when the electronic circuit breaker is turned on or when the ambient temperature of the AD converter 61 is estimated to be a normal temperature, it is estimated from the integrated value of the electric energy within the unit time as the reference time for starting the temperature estimation. The measured temperature change amount is added to the room temperature, and the ambient temperature of the AD converter 61 is estimated. At this time, for example, when the temperature before the addition is normal temperature, an adjustment may be made such that the estimated temperature does not decrease even if the integrated electric energy is 0. Further, the ambient temperature of the AD converter 61 may be estimated from the integrated value of the current within the unit time. Since the temperature rise and fall are estimated based on the integrated value of current information and power information within a predetermined time, the accuracy of the estimated temperature is improved. Thereby, the error caused by the temperature of the AD conversion value can be corrected, and the measurement error of the electric energy can be reduced.

(Third embodiment)
An electronic circuit breaker according to a third embodiment of the present invention will be described with reference to FIG. 4, the same components as those of the electronic circuit breaker in FIG. The electronic circuit breaker 1 of the present embodiment includes an emergency power supply circuit 81 in addition to the configuration of the electronic circuit breaker of the first embodiment. The emergency power supply circuit 81 is, for example, a storage battery, and stores power from the power supply circuit 5 and supplies power to the processing unit 63 and the temperature estimation unit 71 when the contact point 13 is removed. The emergency power supply circuit 81 may be a battery or may be supplied with power from an external power supply.

  Operation | movement of the electronic circuit breaker 1 comprised in this way is demonstrated. When the electric circuit 11 is disconnected and the power supply from the power supply circuit 5 is stopped, the processing unit 63 and the temperature estimation unit 71 maintain the operation by the power supply from the emergency power supply circuit 81 and the ambient temperature of the AD converter 61 is reduced. Continue estimation. Even when the electric circuit 11 is removed, the temperature detection unit 7 and the processing unit 63 operate, and it is possible to estimate the ambient temperature of the AD converter 61 when the temperature drops due to heat radiation. Thus, the ambient temperature of the AD converter 1 can be estimated even when the operation of the electronic circuit breaker 1 is resumed. Thereby, the error caused by the temperature of the AD conversion value can be corrected, and the measurement error of the electric energy can be reduced.

  The capacity of the emergency power supply circuit 81 may be large enough to supply power until the ambient temperature of the AD converter 61 drops to room temperature. If the temperature drops to room temperature, the temperature does not change so much after that. When the operation of the electronic circuit breaker 1 is resumed, the ambient temperature of the AD converter 61 may be estimated to be room temperature.

  Next, a modification of the electronic circuit breaker according to the third embodiment will be described. The electronic circuit breaker 1 of this modification differs from the third embodiment in the operations of the processing unit 63 and the temperature estimation unit 71. The processing unit 63 and the temperature estimation unit 71 of this modification increase the operation cycle when the electric circuit 11 is disconnected and operated by the power supply of the emergency power supply circuit 81. When the electric circuit 11 is tripped, the calculation of electric power in the processing unit 63 and the frequency estimation of the temperature in the temperature estimation unit 71 may be less, the judgment of tripping is not necessary, and the operation cycle can be lengthened. . As described above, since the operation cycle becomes longer and the power consumption of the temperature detection unit and the processing unit is reduced, the power supply capacity of the power supply device can be reduced, and the cost of the electronic circuit breaker can be reduced.

(Fourth embodiment)
An electronic circuit breaker according to a third embodiment of the present invention will be described with reference to FIG. In FIG. 5, the same components as those of the electronic circuit breaker in FIG. The electronic circuit breaker 1 of the present embodiment includes a time information acquisition unit 82 and a nonvolatile storage unit 83 in addition to the configuration of the second embodiment. The time information acquisition unit 82 outputs the time, and the nonvolatile storage unit 83 stores the estimated temperature and time data. The nonvolatile storage unit 83 is, for example, an EEPROM, and may be FRAM, FROM, or the like.

  Operation | movement of the electronic circuit breaker 1 comprised in this way is demonstrated. The processing unit 63 periodically stores the estimated temperature and time data of the ambient temperature of the AD converter 61 in the nonvolatile storage unit 83. Then, when the electric circuit 11 is recovered after being pulled out, the estimated temperature and time immediately before being pulled out and the amount of decrease in temperature can be estimated from the time at the time of recovery, so the AD converter 61 at the time of recovery. The ambient temperature can be estimated. Thereby, the error caused by the temperature of the AD conversion value can be corrected, and the measurement error of the electric energy can be reduced. In addition, the nonvolatile storage unit 82 may store the integrated value of electric energy and the integrated value of current in the second embodiment and the modification thereof described above, and may estimate the ambient temperature of the AD converter 61. The same effect as in the fourth embodiment can be obtained.

  Next, a modification of the electronic circuit breaker according to the fourth embodiment will be described. The electronic circuit breaker 1 of this modification differs from the fourth embodiment in the operation of the processing unit 63. The processing unit 63 stores the estimated temperature and time data in the time information acquisition unit 82 immediately before outputting the trip signal. For example, when the circuit interruption time at 125% of the rated current is 8000 seconds under the overcurrent trip condition, the circuit is tripped when 125% of the current flows for 7999 seconds. The estimated temperature and time data at that time are stored in the nonvolatile storage unit 83. If the trip condition is not reached and the trip is not tripped, the stored data is invalid. Then, when the contact 13 recovers after being pulled off, the estimated temperature and time immediately before being pulled off and the amount of temperature decrease are estimated from the recovery time, and the ambient temperature of the AD converter 61 at the time of recovery is determined. Since it can be estimated, the error of the AD conversion value is reduced, and the measurement error of the electric energy can be reduced. In addition, since the number of times of writing to the nonvolatile storage unit 83 is smaller than that in the fourth embodiment, the lifetime of the nonvolatile storage unit 83 becomes longer, the effort to replace the nonvolatile storage unit 82 is reduced, and the power consumption is also reduced. .

  In addition, this invention is not restricted to the structure of the said various embodiment, A various deformation | transformation is possible in the range which does not change the meaning of invention. For example, the arithmetic circuit 6 may be an IC, and the arithmetic circuit 6 and the temperature estimation unit 71 may be an IC. The same effect can be obtained as when the IC is not implemented.

The block diagram of the electronic circuit breaker which concerns on the 1st Embodiment of this invention. The figure which shows the absolute precision of AD conversion of the AD converter in the same electronic circuit breaker. The block diagram of the electronic circuit breaker which concerns on the 2nd Embodiment of this invention. The block diagram of the electronic circuit breaker which concerns on the 3rd Embodiment of this invention. The block diagram of the electronic circuit breaker which concerns on the 4th Embodiment of this invention. The block diagram of the conventional electronic circuit breaker. The figure which shows the electric current detection performance calculated | required by an electronic circuit breaker.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electronic type circuit breaker 11 Electric circuit 2 Trip circuit part 3 Current detection part 4 Voltage detection part 61 AD converter (AD converter part)
62 Error Correction Unit 63 Processing Unit 7 Temperature Detection Unit 81 Emergency Power Supply Circuit (Power Supply Device)
82 Time information acquisition unit 83 Non-volatile storage unit (storage unit)

Claims (6)

Trip circuit for tripping the electric circuit, current detector for detecting the current flowing in the electric circuit, voltage detector for detecting the voltage of the electric circuit, current information and voltage information detected by the current detector and the voltage detector An electronic converter comprising: an AD converter that converts a digital signal into a digital signal; and a processing unit that outputs a trip signal to the trip circuit unit based on current information or voltage information converted into a digital signal by the AD converter In the vessel
A temperature detector for detecting the ambient temperature of the AD converter;
An error correction unit that corrects at least one of current information and voltage information converted by the AD converter based on the ambient temperature detected by the temperature detection unit;
A relationship table between the integrated value of the amount of power flowing in the electric circuit and the ambient temperature of the AD converter when the electronic circuit breaker is turned on or when the ambient temperature of the AD converter is estimated to be normal temperature And comprising
The ambient temperature of the AD converter rises in proportion to the increase in the integrated value from the reference time of the amount of power flowing in the electric circuit,
The temperature detection unit obtains an integrated value of electric energy calculated from the current information and voltage information with the start time as a reference time of integration, and detects a current ambient temperature of the AD converter determined from the relation table as a detected temperature An electronic circuit breaker that outputs as Trip circuit for tripping the electric circuit, current detector for detecting the current flowing in the electric circuit, voltage detector for detecting the voltage of the electric circuit, current information and voltage information detected by the current detector and the voltage detector An electronic converter comprising: an AD converter that converts a digital signal into a digital signal; and a processing unit that outputs a trip signal to the trip circuit unit based on current information or voltage information converted into a digital signal by the AD converter In the vessel
A temperature detector for detecting the ambient temperature of the AD converter;
An error correction unit that corrects at least one of current information and voltage information converted by the AD converter based on the ambient temperature detected by the temperature detection unit;
A relationship table between an integrated value of the amount of power flowing through the electric circuit within a unit time and a temperature rise and fall value of the AD converter at the time of the integrated value;
The ambient temperature of the AD converter rises or falls according to the integrated value of the amount of power per unit time flowing in the electric circuit,
The temperature detection unit integrates the electric energy within the unit time from the current information and voltage information, starting from when the electronic circuit breaker is turned on or when the ambient temperature of the AD converter is estimated to be normal temperature. A value is obtained, an increase or decrease value of the ambient temperature of the AD converter is determined from the relation table, and an increase or decrease value of the determined ambient temperature is added for each unit time with the ambient temperature at the start as a reference. An electronic circuit breaker characterized in that the ambient temperature of the current AD converter determined by is output as a detected temperature.   The electronic circuit breaker according to claim 1 or 2, further comprising a power supply device that operates at least the temperature detection unit and the processing unit when the electric circuit is tripped.   The electronic circuit breaker according to claim 3, wherein at least one of the temperature detection unit and the processing unit lengthens an operation cycle when the electric circuit is tripped. A non-volatile storage unit, and a time information acquisition unit for acquiring time,
The electronic circuit breaker according to claim 1 or 2, wherein the storage unit stores the integrated value and the time information acquired by the time information acquisition unit.   6. The electronic circuit breaker according to claim 5, wherein the processing unit writes the detected temperature immediately before the current information and the voltage information satisfy an electric circuit tripping condition in the storage unit.

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