Electric energy meter terminal anomaly detection method and electric energy meter

Abstract

The invention discloses an electric energy meter terminal abnormity detection method and an electric energy meter, and relates to the technical field of electronics, and the method comprises the steps: measuring an actual terminal temperature and an actual current value of the electric energy meter, and an actual environment temperature of an environment where the electric energy meter is located; determining a theoretical terminal temperature according to the actual current value and the actual environment temperature; and calculating a difference value between the actual terminal temperature and the theoretical terminal temperature to obtain a detection result. The actual terminal temperature and the actual current value of the electric energy meter and the actual environment temperature of the environment where the electric energy meter is located are measured, then the theoretical terminal temperature is calculated according to the measured values, the theoretical terminal temperature is compared with the actual terminal temperature, the difference value between the theoretical terminal temperature and the actual terminal temperature is calculated, and a detection result is obtained. Whether the temperature of the electric energy meter is abnormal or not can be judged through the detection result. And if the temperature is abnormal, a user can be timely and autonomously indicated or a heat dissipation device is started in an alarm mode, so that the safety of the electric energy meter is ensured.

Description

Technical Field

[0001] The present application relates to the field of electrical technology, and in particular to a method for detecting abnormality of electric energy meter terminals and an electric energy meter. Background Art

[0002] The energy meter is an instrument used to measure electrical energy. It plays a vital role in the power supply system. As the terminal interface between the power grid and the user, its reliability is directly related to the safety of electricity use in thousands of households. In daily use, the energy meter is closely connected with the power supply system to ensure accurate measurement and distribution of electrical energy.

[0003] When the user's electrical equipment has loose wires, poor contact, overload, etc., dangerous temperatures can form at the terminals, which will not only damage the energy meter, but may also directly cause serious safety accidents such as fire. Therefore, it is particularly important to detect abnormal temperature of the energy meter.

[0004] Prior art CN216525977U provides a temperature measurement circuit for an electric energy meter terminal seat. The temperature measurement circuit includes a terminal selection control circuit, a terminal temperature detection circuit and an ADC chip. The input end of the terminal selection control circuit is connected to the MCU, and the output end is connected to the terminal temperature detection circuit. The terminal selection control circuit is used to switch the electric energy meter terminal to be detected; the terminal temperature detection circuit includes two voltage divider circuits, which are respectively connected to the high-voltage terminals of the electric energy meter, and simultaneously detect the ADC sampling values ​​of the current temperature of the two high-voltage terminals of the electric energy meter; the output end of the terminal temperature detection circuit is connected to the ADC chip, and the ADC chip is an analog-to-digital converter supporting differential input, which is used to convert the ADC sampling value into a temperature value, and can be widely used in the temperature measurement circuit of the terminal seat of the electric energy meter.

[0005] However, the alarm temperature setting in this technical solution is usually based on the extreme temperature at which the components in the meter are damaged and cannot work normally. When the system reaches the alarm temperature and triggers the alarm, the electric energy meter may have suffered a certain degree of damage, so it cannot effectively improve the safety of the electric energy meter. Summary of the invention

[0006] In view of this, the main purpose of the present application is to provide a method for detecting abnormality of electric energy meter terminals and an electric energy meter, the purpose of which is to accurately determine the temperature abnormality of the electric energy meter so as to make timely abnormal processing and ensure the safety of the electric energy meter.

[0007] The first aspect of the present application provides a method for detecting abnormality of an electric energy meter terminal, the method comprising:

[0008] Measure and obtain the actual terminal temperature, actual current value and actual ambient temperature of the environment where the electric energy meter is located;

[0009] Determine the theoretical terminal temperature based on the actual current value and the actual ambient temperature;

[0010] The difference between the actual terminal temperature and the theoretical terminal temperature is calculated to obtain the test result.

[0011] In some implementations of the first aspect of the present application, determining the theoretical terminal temperature according to the actual current value and the actual ambient temperature includes:

[0012] The theoretical terminal temperature under the actual ambient temperature and the actual current value is determined according to the reference current, the reference ambient temperature, the reference current and the reference terminal temperature under the reference ambient temperature, the actual ambient temperature, and the actual current value.

[0013] In some implementations of the first aspect of the present application, the theoretical terminal temperature is obtained by the following formula:

[0014]

[0015] Where I0 represents the reference current, T H represents the reference ambient temperature, T0 represents the reference terminal temperature, T H1 represents the actual ambient temperature, I1 represents the actual current value, and T1 represents the theoretical terminal temperature.

[0016] In some implementations of the first aspect of the present application, the method further includes:

[0017] In response to the actual terminal temperature exceeding the first threshold, a trip command is sent to the power meter.

[0018] In some implementations of the first aspect of the present application, the method further includes:

[0019] In response to the detection result exceeding the second threshold, the electric energy meter is instructed to issue an alarm message.

[0020] In some implementations of the first aspect of the present application, the method further includes:

[0021] In response to the detection result falling into the first interval, instructing the electric energy meter not to issue an alarm message;

[0022] In response to the detection result falling into the second interval, instructing the electric energy meter to issue a general alarm message;

[0023] In response to the detection result falling into the third interval, the electric energy meter is instructed to issue a serious alarm message.

[0024] A second aspect of the present application provides an electric energy meter, the electric energy meter comprising:

[0025] The data measurement module is used to measure the actual terminal temperature, the actual current value and the actual ambient temperature of the environment where the electric energy meter is located;

[0026] The temperature calculation module determines the theoretical terminal temperature according to the actual current value and the actual ambient temperature;

[0027] The result generation module calculates the difference between the actual terminal temperature and the theoretical terminal temperature to obtain the detection result.

[0028] In some implementations of the second aspect of the present application, the temperature calculation module is specifically used to:

[0029] The theoretical terminal temperature under the actual ambient temperature and the actual current value is determined according to the reference current, the reference ambient temperature, the reference current and the reference terminal temperature under the reference ambient temperature, the actual ambient temperature, and the actual current value.

[0030] In some implementations of the second aspect of the present application, the temperature calculation module calculates the theoretical terminal temperature by the following formula:

[0031]

[0032] Where I0 represents the reference current, T H represents the reference ambient temperature, T0 represents the reference terminal temperature, T H1 represents the actual ambient temperature, I1 represents the actual current value, and T1 represents the theoretical terminal temperature.

[0033] In some implementations of the second aspect of the present application, the electric energy meter further includes:

[0034] The indication trip module is used to send a trip command to the electric energy meter in response to the actual terminal temperature exceeding the first threshold.

[0035] The technical solution provided by this application has the following beneficial effects:

[0036] In the technical solution provided in the present application, the solution measures the actual terminal temperature of the electric energy meter, the actual current value and the actual ambient temperature of the environment in which the electric energy meter is located, and then calculates the theoretical terminal temperature based on these measured values, and compares them with the actual terminal temperature, and calculates their difference to obtain the detection result. This detection result reflects the degree of deviation between the actual temperature and the theoretical temperature, so that it can be judged whether the electric energy meter has temperature abnormality through the detection result. If the temperature is abnormal, the user can be instructed to turn off the power or start the heat dissipation device in a timely manner autonomously or by alarm, thereby ensuring the safety of the electric energy meter. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 A schematic diagram of a flow chart of a method for detecting abnormality of an electric energy meter terminal provided in an embodiment of the present application;

[0038] Figure 2A flowchart of another method for detecting abnormality of electric energy meter terminals provided in an embodiment of the present application;

[0039] Figure 3 A schematic diagram of a flow chart of a method for detecting abnormality of electric energy meter terminals provided in an embodiment of the present application;

[0040] Figure 4 A flowchart of another method for detecting abnormality of electric energy meter terminals provided in an embodiment of the present application;

[0041] Figure 5 A schematic diagram of a flow chart of a method for detecting abnormality of electric energy meter terminals provided in an embodiment of the present application;

[0042] Figure 6 A schematic diagram of a curve showing a relationship between the terminal temperature inside a meter and the ambient temperature of a 60A, 72A, and 90A electric energy meter when the screws provided in an embodiment of the present application are tightened;

[0043] Figure 7 A schematic diagram of a curve showing a relationship between the terminal temperature inside a meter and the ambient temperature of a 100A, 120A, or 150A electric energy meter when the screws provided in an embodiment of the present application are tightened;

[0044] Figure 8 A schematic diagram of a temperature variation diagram of the terminals in the 60A, 72A and 90A electric energy meters when the screws are tightened provided in an embodiment of the present application;

[0045] Fig. 9 A schematic diagram of a temperature variation diagram of the internal terminals of 100A, 120A, and 150A electric energy meters when the screws provided in an embodiment of the present application are tightened;

[0046] Fig.10 A schematic diagram of the structure of an electric energy meter provided in an embodiment of the present application. DETAILED DESCRIPTION

[0047] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0048] The embodiments of the present application provide a method for detecting abnormality in terminals of an electric energy meter and an electric energy meter.

[0049] See also Figure 1 As shown, an embodiment of the present application provides a method for detecting abnormality of an electric energy meter terminal, the method comprising:

[0050] S101: Measure and obtain the actual terminal temperature, actual current value, and actual ambient temperature of the environment in which the electric energy meter is located.

[0051] In the embodiments of the present application, the terminal refers to the contact point of the electric energy meter connection cable;

[0052] The actual terminal temperature refers to the current temperature of the electric energy meter terminal directly measured by a temperature sensor such as a thermistor or thermocouple. The actual terminal temperature reflects the heat accumulation of the terminal under the current operating state.

[0053] The actual current value refers to the current value currently passing through the energy meter measured by current sensors, shunts and other components. The magnitude of the current will directly affect the heat generated by the terminal. The larger the current, the more heat is generated, and the faster the terminal temperature rises.

[0054] The actual ambient temperature refers to the temperature of the working environment of the energy meter. It is understandable that the higher the ambient temperature, the more difficult it is to dissipate heat and the temperature of the terminal is more likely to rise.

[0055] This step collects the key factors that affect the terminal temperature in real time, taking into account the temperature anomalies caused by ambient temperature and high current, and provides accurate basic data for subsequent temperature anomaly detection.

[0056] S102: Determine a theoretical terminal temperature according to an actual current value and an actual ambient temperature.

[0057] In the embodiments of the present application, the theoretical terminal temperature refers to the temperature that the terminal should reach under specific current and ambient temperature conditions. The theoretical temperature of the electric energy meter terminal is calculated by measuring the actual current and the actual ambient temperature of the terminal, which is used as a reference for subsequent judgment of whether there is a temperature abnormality.

[0058] This step calculates the theoretical terminal temperature to form a reference temperature value for comparison with the actual terminal temperature, providing a reference basis for temperature anomaly detection.

[0059] S103: Calculate the difference between the actual terminal temperature and the theoretical terminal temperature as the detection result.

[0060] In an embodiment of the present application, the difference between the actual terminal temperature and the theoretical terminal temperature is calculated to determine whether there is an abnormal situation. The detection result can be used to indicate whether there is an abnormal situation in the electric energy meter, for example, the temperature is too high or too low.

[0061] Based on the detection results, an alarm or protection mechanism can be triggered, and emergency measures can be taken in time to ensure the safe operation of the electricity meter and avoid damage to the electricity meter.

[0062] In addition, it should be noted that each terminal of the ammeter can be Figure 1 The process shown determines the abnormal terminal temperature and then analyzes the temperature cause of each terminal.

[0063] exist Figure 1 In the process shown, the actual terminal temperature, actual current value and actual ambient temperature of the environment where the energy meter is located are measured, and then the theoretical terminal temperature is calculated based on these measured values, and compared with the actual terminal temperature, and the difference between them is calculated to obtain the detection result. This detection result reflects the degree of deviation between the actual temperature and the theoretical temperature, so that it can be judged whether the energy meter has temperature abnormality through the detection result. If the temperature is abnormal, the user can be instructed to turn off the power or start the heat dissipation device in a timely manner autonomously or through an alarm, thereby ensuring the safety of the energy meter.

[0064] In addition, the principle of the solution provided by the present application is simple, and while increasing the functions, the cost does not increase; and it is able to analyze the real cause of the terminal temperature and accurately determine the poor wiring condition of each terminal.

[0065] See also Figure 2 As shown, the embodiment of the present application further provides a method for detecting abnormality of an electric energy meter terminal, further introduces in detail a method for obtaining the terminal theoretical temperature and disposal measures based on the detection results, specifically including the following steps:

[0066] S201: Measure and obtain the actual terminal temperature, actual current value, and actual ambient temperature of the environment in which the electric energy meter is located.

[0067] S202: Determine a theoretical terminal temperature under the actual ambient temperature and the actual current value according to the reference current, the reference ambient temperature, the reference current and the reference terminal temperature under the reference ambient temperature, the actual ambient temperature, and the actual current value.

[0068] In the embodiments of the present application, a theoretical terminal temperature under current actual conditions is calculated by combining reference values ​​and actual measured values ​​under multiple reference conditions. The reference conditions include reference current and reference ambient temperature. The reference current refers to the standard current value defined under specific conditions; the reference ambient temperature refers to the temperature value of the standard test environment.

[0069] This step calculates the theoretical terminal temperature based on the reference conditions and actual conditions, making the judgment of temperature anomalies more accurate and contributing to the reliability and accuracy of temperature anomaly detection.

[0070] In some implementations of the embodiments of the present application, the theoretical terminal temperature is obtained by the following formula:

[0071]

[0072] Where I0 represents the reference current, T H represents the reference ambient temperature, T0 represents the reference terminal temperature, T H1 represents the actual ambient temperature, I1 represents the actual current value, and T1 represents the theoretical terminal temperature.

[0073] For example, the reference ambient temperature T H The temperature is 23℃, the reference current I0 is 60A, and when we need to know what the temperature T1 should be when the temperature is 70℃ and 80A, we assume that T H When the terminal temperature T0 is 40°C and I0 is 60A, the value of T1 should be:

[0074]

[0075] S203: Calculate the difference between the actual terminal temperature and the theoretical terminal temperature to obtain a detection result.

[0076] S204: In response to the actual terminal temperature exceeding the first threshold, sending a trip command to the electric energy meter.

[0077] In the embodiment of the present application, if the actual terminal temperature exceeds the preset first threshold, it is considered that the terminal temperature is abnormally serious, so the protection mechanism is triggered to cut off the circuit of the electric energy meter by sending a trip command. The trip command can be transmitted to the electric energy meter through the control module, forcing the electric energy meter to be powered off to prevent further temperature rise or equipment failure.

[0078] The present application prevents the terminal temperature from continuing to rise through tripping protection, which can effectively avoid the electric energy meter from malfunctioning due to overheating and protect the safe operation of the electric energy meter.

[0079] S205: In response to the detection result exceeding the second threshold, instruct the electric energy meter to issue an alarm message.

[0080] In an embodiment of the present application, the second threshold is lower than the first threshold. Exceeding this value indicates that the temperature anomaly is developing, but has not yet reached an emergency state requiring tripping, and is used to provide early warning of abnormal temperature. When the detection result exceeds the second threshold but has not yet reached the first threshold, the electric energy meter is instructed to issue an alarm message to remind maintenance personnel to pay attention to the temperature anomaly so that inspection and maintenance can be carried out as soon as possible. Among them, the alarm message refers to the alarm signal issued by the electric energy meter, which can be a sound, a flashing light, or a remote notification transmitted through a communication module.

[0081] This application sends out alarm information as an early warning of temperature anomalies, allowing maintenance personnel to deal with the problem in advance and prevent the temperature from further rising to dangerous levels.

[0082] In some implementations of the present application, in addition to issuing an alarm message, the electric energy meter will also record the alarm event. The recorded alarm event can serve as an important basis for problem tracing and troubleshooting, helping operation and maintenance personnel to quickly locate the cause of the problem. It also helps operation and maintenance personnel understand the operation status of the electric energy meter.

[0083] See also Figure 3 As shown, Figure 3 for Figure 2 One implementation method of the process shown is to first measure the actual current size and the actual ambient temperature MCU, and then calculate the terminal theoretical temperature; then subtract the actual terminal temperature detected to determine whether the difference exceeds 15 degrees Celsius; if it exceeds 15 degrees Celsius, the ammeter executes an alarm action to issue an alarm message and record the event; if it does not exceed 15 degrees Celsius, the ammeter does not execute an alarm action.

[0084] exist Figure 2 In the process shown, a multi-level threshold response mechanism is designed. The device alarm based on the second threshold provides an early warning function, which helps to detect and handle temperature anomalies in a timely manner. The tripping function based on the first threshold ensures that the circuit is quickly cut off when the temperature exceeds the safe range to prevent the electric energy meter from overheating and causing equipment failure or safety accidents. It can be seen that this multi-level response mechanism not only improves the safety of the electric energy meter, but also effectively balances the risk of failure and the normal operation requirements of the equipment.

[0085] See also Figure 4 As shown, the embodiment of the present application further provides a method for detecting abnormality of an electric energy meter terminal, which specifically includes the following steps:

[0086] S401: Measure and obtain the actual terminal temperature, actual current value, and actual ambient temperature of the environment in which the electric energy meter is located.

[0087] S402: Determine a theoretical terminal temperature under the actual ambient temperature and the actual current value according to the reference current, the reference ambient temperature, the reference current and the reference terminal temperature under the reference ambient temperature, the actual ambient temperature, and the actual current value.

[0088] S403: Calculate the difference between the actual terminal temperature and the theoretical terminal temperature to obtain a detection result.

[0089] S404: In response to the detection result falling into the first interval, instruct the electric energy meter not to issue an alarm message.

[0090] In the embodiment of the present application, the first interval is used to represent the range of normal or slight deviation of temperature, which has no significant impact on the safety of the electric energy meter, so no alarm is required. If the detection result falls into the first interval, the system will not trigger any alarm, and the electric energy meter will remain in normal working state. This avoids unnecessary alarms caused by slight temperature fluctuations, helps to reduce false alarm rates, and reduces operation and maintenance interference.

[0091] This application effectively reduces false alarms caused by slight fluctuations by only giving an alarm when the temperature deviates from the normal range, which helps to stabilize the operation of the electricity meter.

[0092] S405: In response to the detection result falling into the second interval, instructing the electric energy meter to issue a general alarm message.

[0093] In the embodiment of the present application, the second interval indicates that the temperature is high but not serious. When the detection result falls into the second interval, it indicates that the temperature fluctuation has exceeded the normal range, but has not yet reached a serious state. Based on this, the electric energy meter will be instructed to issue a general alarm message to remind the operation and maintenance personnel to pay attention to possible abnormalities. Among them, the general alarm signal is usually used to indicate that the temperature deviates from the normal level to attract the attention of the operation and maintenance personnel.

[0094] This application can alert operation and maintenance personnel to possible temperature problems by instructing the device to issue a general alarm message so that preventive measures can be taken before the abnormality worsens.

[0095] S406 In response to the detection result falling into the third interval, instruct the electric energy meter to issue a serious alarm message.

[0096] In the embodiment of the present application, the third interval indicates that the temperature is abnormally serious and may endanger the normal operation of the electric energy meter. When the detection result falls into the third interval, it means that the temperature fluctuation has reached a serious level, and the electric energy meter will issue a serious alarm message, which indicates that the temperature has reached a high risk and the operation and maintenance personnel need to take immediate measures to prevent the temperature from further rising and causing equipment failure or safety accidents.

[0097] This application provides timely high-priority reminders by instructing the electricity meter to issue serious alarm information, thereby reminding operation and maintenance personnel to immediately deal with high-risk temperature anomalies to prevent equipment from overheating and damage, effectively reducing the risk of damage to the electricity meter or other safety accidents.

[0098] exist Figure 4In the process shown, through the graded alarm mechanism, appropriate response measures can be taken for different degrees of temperature anomalies, including: handling normal fluctuations, general and severe temperature anomalies separately, and flexibly responding to temperature fluctuations of different degrees, making the alarm system more reasonable and efficient; operation and maintenance personnel can decide whether and how to handle the alarm according to the severity of the alarm, reduce unnecessary intervention, and improve operation and maintenance efficiency; through timely and accurate alarm classification, the risk of temperature anomalies can be effectively prevented and controlled to ensure the safety of equipment and operating environment.

[0099] See also Figure 5 As shown, Figure 5 for Figure 4 One implementation of the process shown. First, measure the actual current size and the actual ambient temperature MCU, and then calculate the terminal theoretical temperature; then make a difference with the actual terminal temperature detected to determine the interval in which the difference falls. If the difference falls within the range of 0-15 degrees Celsius, the ammeter does not perform an alarm action, but only records this event; if the difference falls within the range of 20-25 degrees Celsius, the ammeter performs an alarm action, issues a general alarm message, and records this event; if the difference falls within the range of 25-35 degrees Celsius, the ammeter performs an alarm action, issues a serious alarm message, and records this event. In addition, if the actual terminal temperature exceeds 135 degrees Celsius, the electric energy meter performs a tripping action. Among them, since the error of the terminal temperature measurement is plus or minus 5 degrees, which exceeds the normal value of 10 degrees, as a deviation value, the difference is selected as 15 degrees to eliminate some errors;

[0100] The present application embodiment tests the terminal temperature of the electric energy meter and obtains the following rule in combination with the theoretical formula:

[0101] Rule 1: The terminal temperature and the ambient temperature are in a superposition state;

[0102] Specifically, see Figure 6 As shown, Figure 6 The curves of the relationship between the ambient temperature and the temperature of each terminal in the 60A, 72A and 90A electric energy meters when the screws are tightened are shown. The solid line is the 60A load current, the dotted line is the 72A load current, and the dot-dash line is the 90A load current. Figure 6 From the analysis, it can be seen that under the same load current, the terminal temperature increases with the increase of ambient temperature; at 70℃ and 90A current, the terminal temperature in the table can reach up to 116℃.

[0103] See also Figure 7 As shown, Figure 7The following is the relationship curve between the ambient temperature and the terminal temperature of 100A, 123A and 150A electric energy meters when the screws are tightened. The solid line is the 100A load current, the dashed line is the 120A load current, and the dotted line is the 150A load current. Figure 7 From the analysis, it can be seen that under the same load current, the terminal temperature increases with the increase of ambient temperature; at 70℃ and 150A current, the terminal temperature in the table can reach up to 158℃.

[0104] Rule 2: The terminal temperature is directly proportional to the square of the current.

[0105] See also Figure 8 as well as Fig. 9 As shown, Figure 8 as well as Fig. 9 The figure is the joint relationship curve of the load current, ambient temperature and the temperature of the terminals inside and outside the meter when the screws are tightened. The solid line is the ambient temperature of 70℃, and the dotted line is the ambient temperature of 23℃. The figure shows the rule: the influence of ambient temperature on the terminals is superimposed, and the difference in ambient temperature is the same as the difference in terminal temperature, that is, the 70℃ curve can basically be obtained by shifting the 23℃ curve by 47℃.

[0106] When analyzing the terminal temperature data, the present application found that, for example, when the ambient temperature was 23°C and the load current was 60A, the internal temperature of terminal 1 was 43.571°C, while at the same ambient temperature, the terminal temperatures were 52.569°C and 69.759°C at 72A and 90A, respectively. The three currents were multiples of I, 1.2I, and 1.5I, respectively. The corresponding temperatures were T120.517°C, T229.569°C, and T346.759°C, respectively, compared to the ambient temperature of 23°C. From this, we can find the rule 1.2 2 ×20.517=29.54, that is: T1 multiplied by the square of the current multiple, is almost equal to T2.

[0107] According to this law, multiple factors coupling can be obtained:

[0108]

[0109] The following can be concluded:

[0110]

[0111] T H : reference ambient temperature;

[0112] I0: reference current;

[0113] T0:T H The terminal temperature measured at the reference ambient temperature and the I0 reference current;

[0114] T1: Terminal temperature measured under I1 current;

[0115] I1: Current applied when the terminal temperature needs to be measured.

[0116] According to the above-mentioned rule that the temperature rise of the terminal is equal to the difference of the ambient temperature under the same current, the formula can be further improved:

[0117] Now with T H For example, when the temperature is 23℃ and I0 is 60A, what is the measured temperature when we need to know the temperature at 70℃ and 80A?

[0118] First, we need to use the controlled variable method. First, we need to make sure that the current is the same as I0, which means that the current is 80A when the ambient temperature is 23℃. Then, we use the formula to calculate T1 when the ambient temperature is 23℃ and the current is 80A. Then, based on the characteristic that the difference in the measurement results of the terminal temperature tests at different ambient temperatures under the same current is equal to the difference in ambient temperature, we can infer that the temperature measured at 70℃ and 80A should be T1+(80-23)℃.

[0119] 23℃ is T H , and T in the T1 formula H It is offset and can eventually evolve into.

[0120]

[0121] T H : reference ambient temperature;

[0122] I0: reference current;

[0123] T0:T H The terminal temperature measured at the reference ambient temperature and the I0 reference current;

[0124] T H1 : The ambient temperature when the terminal temperature needs to be measured;

[0125] T1: Terminal temperature measured under I1 current;

[0126] I1: Current applied when the terminal temperature needs to be measured.

[0127] The above formula is derived from the law obtained from the test data. In theory, the physical meaning of the terminal heating up when current flows into it is analyzed theoretically:

[0128] When the load current is connected to the terminals of the energy meter, the terminals generate heat, and the heat generated is:

[0129] Q=I 2 R

[0130] The measured terminal temperature is actually the terminal heat Q 发 With heat dissipation Q 散 The final temperature value after consumption is now called temperature rise ΔT, so:

[0131] (Q 发 -Q 散 ) / k1=ΔT

[0132] Among them: k1 is the simplified overall external influence coefficient. Since there are too many external factors to list one by one and the impact cannot be quantified, they are directly regarded as a whole, and the coefficient k1 is used to represent the relationship between the external factors and the final temperature rise.

[0133] As for Q 发 With Q 散 There should also be a certain connection between them, which should be a linear relationship. There should be a coefficient k2 between the two, so that the two satisfy:

[0134] Q 散 =k2Q 发

[0135] From this we can get:

[0136] (I 2 RtK2 2 Rt) / k1=ΔT

[0137] After simplification, we can get:

[0138]

[0139] After simplification, it can be found that Rt(1-k2) / k1 is a fixed value regardless of its specific value, so it can be regarded as k as a whole. Therefore, ΔT in the entire formula is only related to the value of the current I, and it is a second-order square multiple relationship. However, this formula is valid only when the ambient temperature is the same as the basic temperature of the terminal. According to the first rule obtained before, under the same load current, the temperature rise of the terminal is almost equal to the difference in ambient temperature, so the relationship can be obtained:

[0140]

[0141] Where: T H1 With T H0 For two ambient temperatures;

[0142] T1 and T0 are the temperatures measured at the same terminal when the same current is loaded at two ambient temperatures.

[0143] After sorting out, the final relationship between the measured terminal temperature under different test environment temperatures and different current conditions is as follows:

[0144]

[0145] T H : reference ambient temperature;

[0146] I0: reference current;

[0147] T0:T H The terminal temperature measured at the reference ambient temperature and the I0 reference current;

[0148] T H1 : The ambient temperature when the terminal temperature needs to be measured;

[0149] T1: Terminal temperature measured under I1 current;

[0150] I1: Current applied when the terminal temperature needs to be measured.

[0151] See also Fig.10 As shown, an embodiment of the present application provides an electric energy meter, which includes:

[0152] The data measurement module 1001 is used to measure the actual terminal temperature, the actual current value and the actual ambient temperature of the environment where the electric energy meter is located;

[0153] The temperature calculation module 1002 determines the theoretical terminal temperature according to the actual current value and the actual ambient temperature;

[0154] The result generation module 1003 calculates the difference between the actual terminal temperature and the theoretical terminal temperature to obtain a detection result.

[0155] In some implementations of the embodiments of the present application, the temperature calculation module is specifically used to:

[0156] The theoretical terminal temperature under the actual ambient temperature and the actual current value is determined according to the reference current, the reference ambient temperature, the reference current and the reference terminal temperature under the reference ambient temperature, the actual ambient temperature, and the actual current value.

[0157] In some implementations of the embodiments of the present application, the temperature calculation module calculates the theoretical terminal temperature by the following formula:

[0158]

[0159] Where I0 represents the reference current, T H represents the reference ambient temperature, T0 represents the reference terminal temperature, T H1 represents the actual ambient temperature, I1 represents the actual current value, and T1 represents the theoretical terminal temperature.

[0160] In some implementations of the embodiments of the present application, the electric energy meter further includes:

[0161] The indication trip module is used to send a trip command to the electric energy meter in response to the actual terminal temperature exceeding the first threshold.

[0162] In some implementations of the embodiments of the present application, the electric energy meter further includes:

[0163] The alarm module is used to instruct the electric energy meter to issue an alarm message in response to the detection result exceeding the second threshold.

[0164] In some implementations of the embodiments of the present application, the electric energy meter includes:

[0165] The alarm module is used to instruct the electric energy meter not to issue an alarm message in response to the detection result falling into the first interval; it is also used to instruct the electric energy meter to issue a general alarm message in response to the detection result falling into the second interval; it is also used to instruct the electric energy meter to issue a serious alarm message in response to the detection result falling into the third interval.

[0166] Finally, it should be noted that, in the embodiments of the present application, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only those elements, but also includes other elements that are not clearly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of more restrictions, the elements limited by the statement "comprise one..." do not exclude the presence of other identical elements in the process, method, article or equipment including the elements.

[0167] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for detecting abnormality of electric energy meter terminals, characterized in that: The method comprises: Measure and obtain the actual terminal temperature, actual current value and actual ambient temperature of the environment in which the electric energy meter is located; Determining a theoretical terminal temperature according to the actual current value and the actual ambient temperature; The difference between the actual terminal temperature and the theoretical terminal temperature is calculated to obtain a detection result.

2. The method according to claim 1, characterized in that The determining of the theoretical terminal temperature according to the actual current value and the actual ambient temperature includes: The theoretical terminal temperature under the actual ambient temperature and the actual current value is determined according to a reference current, a reference ambient temperature, the reference current and a reference terminal temperature under the reference ambient temperature, the actual ambient temperature, and the actual current value.

3. The method according to claim 2, characterized in that The theoretical terminal temperature is obtained by the following formula: Wherein, I0 represents the reference current, T H represents the reference ambient temperature, T0 represents the reference terminal temperature, T H1 represents the actual ambient temperature, I1 represents the actual current value, and T1 represents the theoretical terminal temperature.

4. The method according to claim 1, characterized in that: The method further comprises: In response to the actual terminal temperature exceeding a first threshold, a trip command is sent to the power meter.

5. The method according to claim 1, characterized in that The method further comprises: In response to the detection result exceeding a second threshold, the electric energy meter is instructed to issue an alarm message.

6. The method according to claim 1, characterized in that The method further comprises: In response to the detection result falling into the first interval, instructing the electric energy meter not to issue an alarm message; In response to the detection result falling into the second interval, instructing the electric energy meter to issue a general alarm message; In response to the detection result falling into the third interval, the electric energy meter is instructed to issue a serious alarm message.

7. An electric energy meter, characterized in that: The electric energy meter comprises: A data measurement module, used to measure the actual terminal temperature, the actual current value and the actual ambient temperature of the environment where the electric energy meter is located; A temperature calculation module, which determines a theoretical terminal temperature according to the actual current value and the actual ambient temperature; The result generating module calculates the difference between the actual terminal temperature and the theoretical terminal temperature to obtain a detection result.

8. The electric energy meter according to claim 7, characterized in that: The temperature calculation module is specifically used for: The theoretical terminal temperature under the actual ambient temperature and the actual current value is determined according to a reference current, a reference ambient temperature, the reference current and a reference terminal temperature under the reference ambient temperature, the actual ambient temperature, and the actual current value.

9. The electric energy meter according to claim 8, characterized in that: The temperature calculation module calculates the theoretical terminal temperature by the following formula: Wherein, I0 represents the reference current, T H represents the reference ambient temperature, T0 represents the reference terminal temperature, T H1 represents the actual ambient temperature, I1 represents the actual current value, and T1 represents the theoretical terminal temperature.

10. The method according to claim 7, characterized in that The electric energy meter also includes: The indicative tripping module is configured to send a tripping command to the electric energy meter in response to the actual terminal temperature exceeding a first threshold.

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