Power self-adaptive adjusting method and system

Abstract

The invention discloses a power adaptive adjustment method and system. The method comprises the steps of obtaining an initial resistance value of an equivalent resistor of a power supply line; determining the on-load power of the power supply line according to the initial resistance value of the equivalent resistor; adjusting the working power of a load according to the on-load power, and cutting off the load after running for a preset time according to the adjusted working power to obtain the on-load resistance value of the equivalent resistor of the power supply line; and determining the temperature rise of the power supply line according to the initial resistance value and the load resistance value of the equivalent resistor of the power supply line, and reducing the working power of the load when the temperature rise exceeds a preset temperature rise threshold value. The on-load power of the power supply line is determined through the equivalent resistance of the power supply line, the working power of the load is adjusted according to the actual on-load capacity of the power supply line, and potential safety hazards caused by overload operation of the power supply line can be avoided; and secondly, the temperature rise condition of the power supply line can be monitored, the working power of the load is dynamically adjusted, and the fire risk caused by overheating of the power supply line is avoided.

Description

Technical Field

Background Art

[0003] In order to meet the user's demand for heating speed and avoid affecting the household power supply environment, some electric water heater manufacturers have proposed a "heating power adaptive solution". There are mainly two ways for the "heating power adaptive solution" of existing electric water heaters: 1. According to the preset load power of the power supply line and set a current acquisition circuit at the main switch of the household power supply far from the electric water heater, and transmit it back to the electric water heater wirelessly for determination and processing. The main disadvantages of this method are that it is necessary to preset the load power of the power supply line, but the preset value is not easy to determine because even users may not understand the specifications of their own power supply lines. Therefore, the technical feasibility is not high. Secondly, it is necessary to install a current acquisition device at the main switch of the household power supply and transmit it back to the electric water heater for processing wirelessly, which is not only complex to install but also has low reliability. 2. Adjust the heating power of the electric water heater according to the temperature of the power cord and / or power plug of the electric water heater. This method can only monitor the temperature rise of the power cord and power plug of the electric water heater, and cannot monitor the household power supply line and adapt to the power. Moreover, for a generally qualified electric water heater out of the factory, its power cord and power plug can meet its full power operation and the temperature rise meets the requirements of safety regulations. Therefore, there may be a situation where the temperature of the power cord and / or power plug of the electric water heater is normal, but the load capacity of the power supply line is insufficient. If the electric water heater still operates at a high power at this time, there will also be a risk of serious temperature rise and even fire in the power supply line.

Summary of the Invention

[0005] To achieve the above object, the present invention proposes a power adaptive adjustment method, including the following steps: Obtain the initial resistance value of the equivalent resistance of the power supply line ; According to the initial resistance value of the equivalent resistance , determine the load power of the power supply line; Adjust the operating power of the load according to the on-load power. After operating for a preset time at the adjusted operating power, cut off the load and obtain the on-load resistance value of the equivalent resistance of the power supply line. ; According to the initial resistance value of the equivalent resistance of the power supply line and the on-load resistance value , determine the temperature rise of the power supply line. When the temperature rise exceeds the preset temperature rise threshold, reduce the operating power of the load.

[0006] A power adaptive adjustment method as described above, the obtaining of the initial resistance value of the equivalent resistance of the power supply line , includes: Obtain the no-load voltage of the power supply line before the load is connected. ; Obtain the on-load voltage and on-load current of the power supply line after the load is connected. and the on-load current ; Calculate the no-load voltage , the on-load voltage and the on-load current through Ohm's law to obtain the initial resistance value of the equivalent resistance. , the process includes: .

[0007] A power adaptive adjustment method as described above, the on-load voltage of the power supply line is also used to determine whether the power supply line has a basic on-load capacity to drive the load to work, including: Determine whether the power supply voltage deviation of the power supply line meets the grid standard according to the on-load voltage; If it meets the standard, the power supply line has a basic on-load capacity to drive the load to work; If it does not meet the standard, the on-load capacity of the power supply line is insufficient, and the operating power of the load is reduced.

[0008] A power adaptive adjustment method as described above, the determining of the on-load power of the power supply line according to the initial resistance value of the equivalent resistance , includes: According to the initial resistance value of the equivalent resistance , obtain the resistance value of each meter of wire of the power supply line; According to the resistance value of each meter of wire, obtain the wire cross-sectional area of the power supply line; According to the wire cross-sectional area, obtain the operating current threshold of the power supply line ; According to the operating current threshold , calculate through the power calculation formula to obtain the load power of the power supply line, and its power calculation formula is: ; Among them, P is the load power of the power supply line, and U is the commercial power supply voltage.

[0009] For a power adaptive adjustment method as described above, adjusting the operating power of the load according to the load power includes: Compare the load power with the rated power of the load; If the load power is less than the rated power of the load, adjust the operating power of the load to the load power; If the load power is greater than the rated power of the load, adjust the operating power of the load to the rated power of the load.

[0010] For a power adaptive adjustment method as described above, according to the initial resistance value of the equivalent resistance of the power supply line and the load resistance value to determine the temperature rise of the power supply line, including: According to the initial resistance value and the load resistance value respectively obtain the resistivity corresponding to the initial resistance value and the resistivity through the resistivity calculation formula, and its resistivity calculation formula is:

[0011] Among them, is the resistivity, S is the cross-sectional area of the wire, and L is the length of the power supply line; According to the resistivity and the resistivity obtain the temperature rise of the power supply line through the conversion formula, and its conversion formula is:

[0012] Among them, is the temperature rise of the power supply line, is the resistivity at the reference temperature, is the temperature coefficient.

[0013] For a power adaptive adjustment method as described above, after obtaining the initial resistance value of the equivalent resistance, it further includes: Re-obtain the load voltage and load current after the load is connected; According to the re-acquired on-load voltage and on-load current, calculate again through Ohm's law to obtain the verified resistance value of the power supply line equivalent resistance ; Compare the verified resistance value with the allowable deviation range of the initial resistance value to verify whether the calculated initial resistance value is accurately measured; If the verified resistance value exceeds the allowable deviation range of the initial resistance value , then temporarily set the verified resistance value as the initial resistance value , and repeat the above steps to recalculate the verified resistance value of the power supply line equivalent resistance until the verified resistance value meets the requirements, and set the last verified resistance value that meets the requirements as the initial resistance value .

[0014] A power adaptive adjustment method as described above, the step of obtaining the on-load resistance value of the power supply line equivalent resistance is the same as the step of obtaining the initial resistance value of the power supply line equivalent resistance .

[0015] In addition, to achieve the above object, the present invention also proposes a power adaptive adjustment system, including: a voltage measurement circuit, a current measurement circuit, a current induction coil, a main control circuit, and a power adjustment circuit; The signal input end of the voltage measurement circuit is used to measure the voltage of the power supply line; The signal input end of the current measurement circuit is connected to the current induction coil, and the wire of the power supply line passes through the magnetic core of the current induction coil to measure the current of the power supply line through the principle of electromagnetic induction; The signal input end of the main control circuit is respectively connected to the signal output end of the voltage measurement circuit and the signal output end of the current measurement circuit, and the signal output end of the main control circuit is used to output a power adjustment signal; The input end of the power adjustment circuit is connected to the signal output end of the main control circuit, and the output end of the power adjustment circuit is connected to the load, and is used to adjust the power of the load according to the power adjustment signal.

[0016] A power adaptive adjustment system as described above further includes a on-off control circuit, the signal input end of the on-off control circuit is connected to the main control circuit, and the signal output end of the on-off control circuit is connected to the power adjustment circuit.

[0017] Compared with the prior art, a power adaptive regulation method and system proposed by the present invention have the following beneficial effects: 1. By determining the load power of the power supply line through the equivalent resistance of the power supply line, and then adjusting the working power of the load according to the actual load capacity of the power supply line, the present invention can avoid the safety hazards caused by overloading of the power supply line, and can also make the electrical appliances work at the maximum power as much as possible; secondly, it can also monitor the temperature rise of the power supply line and dynamically adjust the working power of the load to avoid the fire risk caused by overheating of the power supply line.

[0018] 2. The power adaptive regulation method and system proposed by the present invention do not need to preset the load power of the power supply line according to the actual power supply line situation, do not need to set current and temperature acquisition devices outside, and do not need to wirelessly transmit current information, greatly improving the reliability or feasibility of the power adaptive scheme.

[0019] 3. By judging whether the load voltage of the power supply line meets the grid standard to evaluate the load capacity of the power supply line, the present invention can ensure that the power supply voltage deviation meets the regulations of the grid standard, guarantee the power quality of the power supply line; at the same time, it can also avoid affecting the use of other electrical equipment when the load is satisfied.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a flowchart of a power adaptive regulation method of the present invention; Figure 2 is Figure 1 the specific flowchart of step S1 in Figure 3 is Figure 2 the specific flowchart of step S12 in Figure 4 is Figure 1 the specific flowchart of step S2 in Figure 5 is Figure 1 the specific flowchart of step S3 in Figure 6 is Figure 1 the specific flowchart of step S4 in Figure 7 It is the specific flowchart for the present invention to verify the equivalent resistance of the power supply line; Figure 8 It is the circuit structure block diagram of a power adaptive regulation system of the present invention.

DETAILED DESCRIPTION

[0023] Please refer to Figures 1 to 7 As shown, an embodiment of the present invention proposes a power adaptive adjustment method, including steps S1 - S4, where: S1, obtain the initial resistance value of the equivalent resistance of the power supply line .

[0024] Specifically, the power supply line is the distribution line arranged during the home decoration of users, and the initial resistance value can first measure the no-load voltage of the power supply line before the load is connected by using a voltage measurement circuit with the function of measuring the voltage of the power supply line, then measure the on-load voltage after the load of the power supply line is connected, measure the on-load current of the power supply line after the load is connected by using a current measurement circuit with the function of measuring the current of the power supply line, and then calculate the initial resistance value through Ohm's law based on the data obtained from the above measurements .

[0025] Among them, the load may include, but is not limited to, household appliances such as electric water heaters and warm air heaters.

[0026] In the embodiments of this specification, when an electric water heater (i.e., the load) is connected to the power supply line, the power adaptive adjustment method mainly takes the adaptive adjustment of the working power of the electric water heater as an example of the implementation scenario for illustration. When other household appliances are connected to the power supply line, it can be implemented with reference to this scenario. In addition, the wire material used for the power supply line can be copper wire or aluminum wire. This embodiment takes copper wire as an example for illustration. As for the power supply line using other wire materials, it can be implemented with reference to this embodiment, and the details will not be elaborated herein.

[0027] Further, as a preferred implementation manner rather than a limitation of this solution, step S1 includes steps S11 - S13, where: S11, obtain the no-load voltage of the power supply line before the load is connected ; S12, obtain the on-load voltage and on-load current of the power supply line after the load is connected; S13, calculate the no-load voltage , the on-load voltage and on-load current through Ohm's law to obtain the initial resistance value of the equivalent resistance , and the process includes: 。

[0028] Specifically, a voltage measurement circuit with the function of measuring the voltage of the power supply line is used to first measure the no-load voltage of the electric water heater when it is not connected to the power supply line. Since the electric water heater is not connected to the power supply line at this time, there is no current flowing through the power supply line. Therefore, the measured no-load voltage is the mains supply voltage.

[0029] Similarly, the loaded voltage of the electric water heater when it is connected to the power supply line is measured through the voltage measurement circuit , and the loaded current of the electric water heater when it is connected to the power supply line is measured through a current measurement circuit with the function of measuring the current of the power supply line ; Among them, when measuring the loaded voltage and loaded current of the electric water heater, in order to avoid the temperature rise of the power supply line caused by long-term connection, which affects the accuracy of the initial resistance value of the equivalent resistance of the power supply line and the voltage stability, the connection time for measurement of the electric water heater should be as short as possible. In this embodiment, the measurement connection time is controlled within 1 second. However, in specific implementation, the measurement connection time can be adjusted accordingly according to actual use.

[0030] In addition, in order to avoid the influence of voltage fluctuations in the power supply line, when measuring the no-load voltage of the electric water heater before it is connected to the power supply line , as well as the loaded voltage and loaded current after it is connected to the power supply line, the interval time between the two measurements should also be as short as possible.

[0031] Further, as a preferred implementation manner rather than a limitation of this solution, the loaded voltage of the power supply line is also used to determine whether the power supply line has a basic load-carrying capacity to drive the load to work, including steps S121 - S123, where: S121, according to the loaded voltage , determine whether the power supply voltage deviation of the power supply line meets the grid standard; S122, if it meets the standard, the power supply line has a basic load-carrying capacity to drive the load to work; S123, if it does not meet the standard, the load-carrying capacity of the power supply line is insufficient, and the working power of the load is reduced.

[0032] Specifically, the grid standard is the GB / T12325 - 2008 "Power Quality - Supply Voltage Deviation" standard. The GB / T12325 - 2008 "Power Quality - Supply Voltage Deviation" standard stipulates that the power supply voltage deviation for 220V single-phase power supply (i.e., mains supply) is between -10% and +7% of the nominal voltage. By measuring the loaded voltage of the electric water heater when it is connected to the power supply line Compare with the standard of GB / T 12325-2008 "Power Quality - Supply Voltage Deviation". If the loaded voltage is within the range of supply voltage deviation specified in the standard of GB / T 12325-2008 "Power Quality - Supply Voltage Deviation", the load-carrying capacity of the power supply line can drive the electric water heater to work, that is, the power supply line can meet the full-power operation of the electric water heater at the rated power; if the loaded voltage exceeds the range of supply voltage deviation specified in the standard of GB / T 12325-2008 "Power Quality - Supply Voltage Deviation", the load-carrying capacity of the power supply line is insufficient and cannot meet the full-power operation of the electric water heater, and it is necessary to reduce the working power of the electric water heater.

[0033] In addition, when other electrical equipment is connected to the power supply line in addition to the electric water heater, it is also possible to compare the loaded voltage of the power supply line with the standard of GB / T 12325-2008 "Power Quality - Supply Voltage Deviation" to evaluate whether the power supply line has sufficient load-carrying capacity to drive the electric water heater and other electrical equipment to work simultaneously, so as to avoid affecting the use of other electrical equipment when the electric water heater is satisfied.

[0034] In this embodiment, using the standard of GB / T 12325-2008 "Power Quality - Supply Voltage Deviation" to evaluate the load-carrying capacity of the power supply line can ensure that the supply voltage deviation meets the regulations of the grid standard, guarantee the power quality of the power supply line, and reduce the damage to electrical equipment caused by voltage fluctuations; at the same time, it can also be used as an index for fault diagnosis of electrical equipment to help quickly locate problems, perform maintenance and repair in a timely manner, and reduce the impact on users.

[0035] S2. Determine the load-carrying power of the power supply line according to the initial resistance value of the equivalent resistance .

[0036] In this embodiment, through the initial resistance value of the equivalent resistance, the cross-sectional area of the wire of the power supply line and the working current threshold are deduced, so as to obtain the load-carrying power of the power supply line, and then the maximum working current that the power supply line can safely carry can be obtained, ensuring that the subsequent adjustment of the working power of the electric water heater will not exceed the safety current threshold of the power supply line, avoiding excessive temperature rise of the power supply line and potential fire risks, and also avoiding damage to other equipment of the power supply system.

[0037] Further, as a preferred implementation manner rather than a limitation of this solution, the step S2 includes steps S21-S24, where: S21. Obtain the resistance value of the wire per meter of the power supply line according to the initial resistance value of the equivalent resistance . S22. Obtain the wire cross-sectional area of the power supply line according to the resistance value per meter of the wire. S23. Obtain the working current threshold of the power supply line according to the wire cross-sectional area. ; S24. According to the working current threshold , perform calculations through the power calculation formula to obtain the load-carrying power of the power supply line. The power calculation formula is: ; where P is the load-carrying power of the power supply line and U is the mains supply voltage.

[0038] In this embodiment, taking the assumed no-load voltage as 220V, the load-carrying voltage as 210V, and the load-carrying current as 25A as an example for illustration. In the actual use process, the specific values of the actually measured no-load voltage , load-carrying voltage , and load-carrying current shall be implemented with reference to this embodiment, and this application will not elaborate further here.

[0039] Specifically, first, according to the above data, the resistance value of the equivalent resistance can be calculated as 400 mΩ through Ohm's law. It should be noted that 400 mΩ is the resistance of the entire power supply line from the mains transformer to the electrical appliance side. However, since the resistance of the power supply line in a user's home is generally within 200 mΩ and the length of the power supply line is generally about 40 m, the initial resistance value of the equivalent resistance of the power supply line can be obtained as 200 mΩ; Then, according to the initial resistance value of 200 mΩ and the line length of 40 m, the resistance value per meter of the wire can be calculated as 5 mΩ / m; Next, by comparing the resistance value per meter of the wire of 5 mΩ / m with the conductor resistance values specified in the GB / T 3956−2008 "Conductors of Cables" standard, the wire cross-sectional area of the power supply line can be obtained. For example, in this embodiment, the calculated resistance value per meter of the wire is 5 mΩ / m. After comparison, it can be known that the cross-sectional area of the wire is 4.0 ; Secondly, according to the current-carrying capacity of the copper wire, the working current threshold of the power supply line can be known. The current-carrying capacity refers to the maximum current that the wire can withstand under safe conditions. The current-carrying capacity of the copper wire can be directly obtained from commonly used manuals in the industry. For example, from the wire load current values specified in the GB / T 4706.1−2005 standard, the current-carrying capacity ranges corresponding to different cross-sectional areas can be found; Finally, using the power calculation formula, the load power of the power supply line can be obtained. For example, in this embodiment, the cross-sectional area of the wire is 4.0 , it can be known that the safe current-carrying capacity of the wire under this cross-sectional area is 32A. Therefore, the load power P of the wire under this cross-sectional area is P = 32×220 = 7040W, that is, the power supply line can withstand the operation of an electric water heater with a rated working power of 7KW.

[0040] Among them, since the current-carrying capacity is closely related to factors such as its cross-sectional area, material, and temperature, and the cross-sectional area of the wire in the household power supply line is generally between 1 and 10 , therefore, in this embodiment, in combination with the above-mentioned GB / T3956﹣2008 "Conductors of Cables" standard, partial data tables corresponding to the cross-sectional area of the wire, safe current-carrying capacity, and load power corresponding to different wire resistances are obtained; The partial data tables are as follows:

[0041] S3. According to the load power, adjust the working power of the load, and after running for a preset time at the adjusted working power, cut off the load to obtain the load resistance value of the equivalent resistance of the power supply line .

[0042] Specifically, according to the load power obtained in the previous steps, it can be judged whether the load power of the power supply line has the ability to withstand the full power operation of the electric water heater. For example, the load voltage in the previous embodiment is 210V and the load current is 25A. It can be known that the working current of the electric water heater when operating at full power is 25A, and the working power is 5250W. And the safe working current of this power supply line is 32A, and the load power is 7040W. Therefore, this power supply line can meet the full power operation of the electric water heater without reducing the working power of the electric water heater. By confirming the actual load-bearing capacity of the power supply line and reasonably adjusting the working power of the electric water heater, it is possible to prevent electrical failures or potential safety hazards caused by the overloading operation of the power supply line.

[0043] In addition, after the electric water heater runs at the adjusted working power for a preset time, switching the connection between the electric water heater and the power supply line can help monitor the temperature rise of the power supply line, further confirm whether the power supply line can stably support the electric water heater to work at the adjusted working power, and improve the reliability of the system operation; Among them, the preset time is generally set to 10 minutes. In specific implementation, the setting of the preset time can be adjusted accordingly according to the actual situation.

[0044] Furthermore, as a preferred implementation manner rather than a limitation of this solution, the obtaining of the load resistance value of the equivalent resistance of the power supply line The steps are the same as those for obtaining the initial resistance value of the equivalent resistance of the power supply line in step S1. are the same.

[0045] Further, as a preferred implementation manner rather than a limitation of this solution, step S3 includes steps S31 - S33, where: S31, compare the load power with the rated power of the load; S32, if the load power is less than the rated power of the load, adjust the operating power of the load to the load power; S33, if the load power is greater than the rated power of the load, adjust the operating power of the load to the rated power of the load.

[0046] In this embodiment, adjusting the operating power of the electric water heater according to the actual load power of the power supply line can ensure that the electric water heater operates at the maximum efficiency without exceeding the load capacity of the power supply line, reducing unnecessary energy waste; at the same time, it can also prevent the power supply line from overloading and potential safety risks.

[0047] S4, according to the initial resistance value of the equivalent resistance of the power supply line and the load resistance value , determine the temperature rise of the power supply line, and when the temperature rise exceeds the preset temperature rise threshold, reduce the operating power of the load.

[0048] Specifically, when the electric water heater operates for a preset time, disconnect it from the power supply line, and measure the load resistance value of the equivalent resistance of the power supply line at this time , and from the resistivity calculation formula, the resistivity of the initial resistance value and the resistivity of the load resistance value at this time can be obtained, and then the temperature rise of the power supply line at this time is deduced, and when the temperature rise exceeds the preset temperature rise threshold, reduce the operating power of the electric water heater; wherein, the preset temperature rise threshold is set to 35°C, that is, when the temperature rise of the power supply line exceeds 35°C, it is necessary to immediately reduce the operating power of the electric water heater. In specific implementation, the setting of the preset temperature rise threshold can be adjusted according to the actual situation.

[0049] Further, as a preferred implementation manner rather than a limitation of this solution, step S4 includes steps S41 - S42, where: S41, according to the initial resistance value and the load resistance value , through the resistivity calculation formula, respectively obtain the resistivity corresponding to the initial resistance value and the load resistance value respectively and resistivity , and its resistivity calculation formula is:

[0050] wherein, is the resistivity, S is the cross-sectional area of the wire, and L is the length of the power supply line.

[0051] S42. According to the resistivity and the resistivity , the temperature rise of the power supply line is obtained through a conversion formula, and its conversion formula is:

[0052] wherein, is the temperature rise of the power supply line, is the resistivity at the reference temperature, is the temperature coefficient.

[0053] Specifically, for the convenience of calculation, the initial resistance value of the equivalent resistance of the power supply line calculated and obtained can be defined as the reference resistivity , and then by measuring the on-load resistance value of the equivalent resistance of the power supply line after the water heater operates for a preset time, the resistivity of the equivalent resistance of the power supply line at this time can be obtained, and then the temperature rise situation of the power supply line at this time can be obtained; wherein, the temperature coefficient

[0054] of the copper wire is 0.00393 / ℃.

[0055] In this embodiment, by real-time monitoring and accurately calculating the temperature rise of the power supply line, and dynamically adjusting the working power of the water heater according to the temperature rise situation of the power supply line, electrical faults and fire risks caused by overheating of the power supply line can be avoided; secondly, by controlling the temperature rise of the power supply line, it helps to reduce the damage of other electrical equipment connected to the power supply line and extend the service life of the entire electrical system. After obtaining the initial resistance value of the equivalent resistance, steps S51 - S54 are further included, wherein: S51, re-obtain the on-load voltage and on-load current after the load is connected; S52, according to the re-obtained on-load voltage and on-load current, calculate again through Ohm's law to obtain the verification resistance value of the equivalent resistance of the power supply line; S53, compare the verification resistance value Compare with the allowable deviation range to verify the calculated initial resistance value Whether the measurement is accurate; S54. If the verified resistance value exceeds the allowable deviation range of the initial resistance value then set the verified resistance value temporarily as the initial resistance value and repeat the above steps to recalculate the verified resistance value of the equivalent resistance of the power supply line until the verified resistance value meets the requirements, and set the last verified resistance value that meets the requirements as the initial resistance value .

[0056] Steps S51 - S54 are steps for verifying the initial resistance value of the equivalent resistance obtained in the above steps The purpose is to ensure the accurate measurement of the equivalent resistance and avoid inaccurate assessment of the load - carrying capacity of the power supply line due to excessive measurement errors. It should be noted that although steps S51 - S54 are for verifying the initial resistance value of the equivalent resistance in the embodiments of this specification, the verification of the load - carrying resistance value of the equivalent resistance is also equally applicable

[0057] Specifically, the allowable deviation range of the initial resistance value can be set to ±10% of the initial resistance value . In specific implementation, the allowable deviation range of the initial resistance value can be set according to the actual usage situation

[0058] Among them, if the verified resistance value is within the range of ±10% of the initial resistance value , it indicates that the measurement of the initial resistance value is accurate; If the verified resistance value exceeds the range of ±10% of the initial resistance value , it indicates that the measurement error of the initial resistance value is too large. At this time, the initial resistance value should be excluded, and the measured verified resistance value should be temporarily set as the initial resistance value , and then a new verified resistance value of the equivalent resistance of the power supply line is calculated through the above steps , and it is judged whether the verified resistance value is within the range of the verified resistance value temporarily set as the initial resistance value of the verified resistance value within the range of ±10%, if so, it indicates that the verified resistance value has a relatively accurate measurement result and can be used as the initial resistance value ; if not, it indicates that the verified resistance value still has a large error in the measurement result. At this time, a new verified resistance value needs to be obtained according to the foregoing steps , and so on, until the verified resistance value is within the range of ±10% of the verified resistance value , and the finally satisfied verified resistance value is set as the initial resistance value .

[0059] For better understanding, in this embodiment, it is assumed that the initially obtained initial resistance value = 200 mΩ is taken as an example for illustration. In actual use, it is implemented with the specifically obtained initial resistance value , and the present application will not elaborate further here.

[0060] If the initially obtained initial resistance value = 200 mΩ, then the allowable deviation range of the initial resistance value is 180 mΩ - 220 mΩ. If the verified resistance value = 210 mΩ, it indicates that the measurement result of the initial resistance value is accurate. If the verified resistance value = 230 mΩ, it indicates that the measurement error of the initial resistance value is too large and cannot be adopted. At this time, the verified resistance value = 230 mΩ is tentatively set as the initial resistance value . At this time, the allowable deviation range of the initial resistance value is 207 mΩ - 253 mΩ, and a verified resistance value is obtained again. If the verified resistance value = 260 mΩ at this time, it indicates that there is still a situation of too large error when the verified resistance value is used as the initial resistance value. And so on, until the verified resistance value is within the range of ±10% of the verified resistance value , and the finally satisfied verified resistance value is set as the initial resistance value .

[0061] In this embodiment, the initial resistance value and the verification resistance value of the power supply line equivalent resistance are obtained by the same method. The verification resistance value is used to verify whether there is an excessive measurement error in the initial resistance value, ensuring the accurate measurement of the equivalent resistance and avoiding inaccurate evaluation of the load-carrying capacity of the power supply line due to excessive measurement error, thereby avoiding the situation where the power of the electric water heater exceeds the actual load-carrying power of the power supply line; accurate measurement and accurate evaluation of the load-carrying capacity of the power supply line can ensure more accurate and reliable adjustment of the working power of the electric water heater.

[0062] For a power adaptive adjustment method based on the embodiment of the present invention, please refer to Figure 8 As shown, the embodiment of the present invention further provides a power adaptive adjustment system, and the power adaptive adjustment system includes: a voltage measurement circuit 100, a current measurement circuit 200, a current induction coil 300, a main control circuit 400, and a power adjustment circuit 500; The signal input end of the voltage measurement circuit 100 is used to measure the voltage of the power supply line; The signal input end of the current measurement circuit 200 is connected to the current induction coil 300, and the wire of the power supply line passes through the current induction coil 300 to measure the current of the power supply line through the principle of electromagnetic induction; The signal input ends of the main control circuit 400 are respectively connected to the signal output end of the voltage measurement circuit 100 and the signal output end of the current measurement circuit 200, and the signal output end of the main control circuit 400 is used to output a power adjustment signal; The input end of the power adjustment circuit 500 is connected to the signal output end of the main control circuit 400, and the output end of the power adjustment circuit 500 is connected to the load, and is used to adjust the power of the load according to the power adjustment signal.

[0063] Further, as a preferred implementation manner rather than a limitation of this solution, the voltage measurement circuit 100 is used to measure the no-load voltage of the power supply line in step S11 、measure the loaded voltage of the power supply line in step S12 、measure the loaded voltage after the load runs for a preset time and is disconnected in step S3 、and measure the verification loaded voltage for verifying the accuracy of the initial resistance value in step S14. The signal output end of the voltage measurement circuit 100 is connected to the signal input end of the main control circuit 400, and transmits the measured voltage result to the main control circuit 400.

[0064] Further, as a preferred implementation manner rather than a limitation of this solution, the current measurement circuit 200 is used to measure the loaded current of the power supply line in step S12 、measure the loaded current after the load runs for a preset time and is disconnected in step S3 and the verification load current used to verify the accuracy of the initial resistance value in the measurement step S14. The signal output end of the current measurement circuit 200 is connected to the signal input end of the main control circuit 400, and the measured current result is transmitted to the main control circuit 400.

[0065] Among them, the current measurement circuit 200 measures the current through the current induction coil 300. The specific principle is as follows: The wire of the power supply line passes through the central hole of the magnetic core of the current induction coil 300. When there is current flowing through the wire of the power supply line, an alternating magnetic field corresponding to the current intensity will be generated around the wire. The magnetic flux of the electromagnetic induction coil 300 will change with the change of the current flowing through the wire, so as to induce an electromotive force corresponding to the current magnitude, and then the current of the power supply line can be measured through the electromagnetic induction coil 300.

[0066] Further, as a preferred implementation manner of this solution rather than a limitation, the main control circuit 400 includes an information processing and control chip, and the information processing and control chip is configured to: obtain the initial resistance value of the equivalent resistance of the power supply line ; determine the load power of the power supply line according to the initial resistance value of the equivalent resistance ; adjust the working power of the load according to the load power, and after operating for a preset time at the adjusted working power, cut off the load to obtain the loaded resistance value of the equivalent resistance of the power supply line ; determine the temperature rise of the power supply line according to the initial resistance value and the loaded resistance value of the equivalent resistance of the power supply line, and when the temperature rise exceeds the preset temperature rise threshold, reduce the working power of the load.

[0067] Among them, the information processing and control chip integrates a formula algorithm, which can perform operations on the received voltage result and current result, and can obtain, including but not limited to, the initial resistance value of the equivalent resistance of the power supply line , loaded resistance value , resistivity, load power, and temperature rise of the power supply line. The formula algorithm includes but not limited to Ohm's law algorithm, power algorithm, resistivity algorithm, and temperature rise algorithm.

[0068] Further, as a preferred implementation manner of this solution rather than a limitation, the power adaptive adjustment system further includes a switching control circuit 600. The signal input end of the switching control circuit 600 is connected to the main control circuit 400, and the signal output end of the switching control circuit 600 is connected to the power adjustment circuit 500. The switching control circuit 600 is used to receive the on / off instruction of the main control circuit 400 to control the connection state between the power adjustment circuit 500 and the load.

[0069] In this embodiment, when it is necessary to measure the no-load voltage of the power supply line before connecting the load, the loaded voltage and the loaded current after connecting the load to the power supply line, the on / off control circuit 500 can be used to control the conduction / disconnection of the load. In addition, when an abnormality occurs in the power supply line, such as excessive temperature rise, the load can also be cut off in time through the on / off control circuit 500, so as to avoid the continuous operation of the load when the temperature rise of the power supply line gets out of control, thereby reducing the continuous increase in the temperature rise of the power supply line and also reducing the damage to the load.

[0070] Furthermore, the above adjustment method is implemented based on the hardware structure of the adjustment system of this embodiment. Therefore, the beneficial effects brought by the above power adaptive adjustment method also exist in this embodiment by the same token.

[0071] Those of ordinary skill in the art should understand that as described above, an implementation manner is provided in combination with specific content, and it is not considered that the specific implementation of the present invention is only limited to these descriptions. At the same time, due to different industry names, it is not limited to the above names, nor limited to English names. Any approximation or similarity to the method and structure of the present invention, or any technical deduction or substitution made under the premise of the inventive concept of the present invention, should be regarded as within the protection scope of the present invention.

Claims

1. A power adaptive adjustment method, characterized in that, Including: Obtain the initial resistance value of the equivalent resistance of the power supply line ; Based on the initial resistance value of the equivalent resistance , determine the load power of the power supply line; According to the on-load power, adjust the operating power of the load, and after operating for a preset time at the adjusted operating power, cut off the load to obtain the on-load resistance value of the equivalent resistance of the power supply line ; Based on the initial resistance value of the power supply line equivalent resistance and the load resistance value , determine the temperature rise of the power supply line, and when the temperature rise exceeds a preset temperature rise threshold, reduce the operating power of the load.

2. The power self-adaptive adjustment method according to claim 1, wherein Obtaining the initial resistance value of the equivalent resistance of the power supply line , including: Obtain the no-load voltage of the power supply line before the load is connected ; After the acquisition load is turned on, the loaded voltage of the power supply line and the loaded current ; The no-load voltage and the loaded voltage and the load current are calculated by Ohm's law to obtain the initial resistance value of the equivalent resistance. The process includes: 。 3. A power self - adapting adjustment method according to claim 2, characterized in that, The on-load voltage of the power supply line is also used to determine whether the power supply line has the basic on-load capacity to drive the load to work, including: Determining whether the power supply voltage deviation of the power supply line meets the grid standard according to the on-load voltage; If it meets the standard, the power supply line has the basic on-load capacity to drive the load to work; If it does not meet the standard, the on-load capacity of the power supply line is insufficient, and the working power of the load is reduced.

4. A power self - adaptive adjustment method according to claim 1, characterized in that, According to the initial resistance value of the equivalent resistance , determining the load power of the power supply line, including: Based on the initial resistance value of the equivalent resistance , the resistance value of each meter of wire in the power supply line is obtained; Obtaining the wire cross-sectional area of the power supply line according to the resistance value of each meter of wire; Obtain the operating current threshold of the power supply line according to the cross-sectional area of the wire ; According to the working current threshold , calculate through the power calculation formula to obtain the load-carrying power of the power supply line, and its power calculation formula is: ； Where P is the on-load power of the power supply line and U is the mains power supply voltage.

5. A power self - adaptive adjustment method according to claim 1, characterized in that, The adjusting the working power of the load according to the on-load power includes: Comparing the on-load power with the rated power of the load; If the on-load power is less than the rated power of the load, adjusting the working power of the load to the on-load power; If the on-load power is greater than the rated power of the load, adjusting the working power of the load to the rated power of the load.

6. A power self - adaptive adjustment method according to claim 1, characterized in that, The initial resistance value of the equivalent resistance of the power supply line and the load resistance value , to determine the temperature rise of the power supply line, including: According to the initial resistance value and the on-load resistance value , through the resistivity calculation formula, the resistivity corresponding to the initial resistance value and the resistivity corresponding to the on-load resistance value are obtained respectively. The resistivity calculation formula is as follows: Among them, is the resistivity, S is the cross-sectional area of the wire, and L is the length of the power supply line; According to the resistivity and the resistivity , the temperature rise of the power supply line is obtained through a conversion formula, and the conversion formula is: Wherein, is the temperature rise of the power supply line, is the resistivity at the reference temperature, is the temperature coefficient.

7. A power self - adapting adjustment method according to claim 2, characterized in that, Obtain the initial resistance value of the equivalent resistance After that, it further includes: Re-obtaining the on-load voltage and on-load current after the load is connected; According to the re-acquired on-load voltage and on-load current, calculate again through Ohm's law to obtain the verified resistance value of the equivalent resistance of the power supply line ; Compare the verified resistance value with the allowable deviation range of the initial resistance value to verify whether the calculated initial resistance value is accurately measured; If the verified resistance value exceeds the allowable deviation range of the initial resistance value , then the verified resistance value shall be tentatively set as the initial resistance value , and repeat the above steps to recalculate the verified resistance value of the equivalent resistance of the power supply line , until the verified resistance value meets the requirements, and set the last verified resistance value that meets the requirements as the initial resistance value .

8. A power self - adaptive adjustment method according to claim 1, characterized in that, The step of obtaining the loaded resistance value of the equivalent resistance of the power supply line is the same as the step of obtaining the initial resistance value of the equivalent resistance of the power supply line ​ 9. A power adaptive regulation system, characterized in that, Including: A voltage measurement circuit, a current measurement circuit, a current induction coil, a main control circuit, and a power adjustment circuit; The signal input end of the voltage measurement circuit is used to measure the voltage of the power supply line; The signal input end of the current measurement circuit is connected to the current induction coil, and the wire of the power supply line passes through the magnetic core of the current induction coil, and the current of the power supply line is measured by the principle of electromagnetic induction; The signal input end of the main control circuit is respectively connected to the signal output end of the voltage measurement circuit and the signal output end of the current measurement circuit, and the signal output end of the main control circuit is used to output a power adjustment signal; The input end of the power adjustment circuit is connected to the signal output end of the main control circuit, and the output end of the power adjustment circuit is connected to the load, and is used to adjust the power of the load according to the power adjustment signal.

10. A power self - adaptive regulation system according to claim 9, characterized in that, It further includes a switch control circuit, the signal input end of the switch control circuit is connected to the main control circuit, and the signal output end of the switch control circuit is connected to the power adjustment circuit.

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