A control system and control method for cable heating protection

Abstract

The invention relates to a control system and a control method for cable heating protection, belonging to the technical field of heating cable protection control, and comprising the following steps: step 1): temperature detection, detecting the heat collection temperature of the cable; step 2): comparing the detected heat collection temperature in the overload working state of the cable with the heat collection temperature in the normal working state of the cable by using a time period temperature method, and comparing the heat collection temperature difference in the two working states by using a temperature difference comparison method; step 3): electric energy calculation, calculating the electric energy consumption of the cable; step 4): calculating the heat utilization rate by using a heat loss method according to the electric energy consumption of the cable in the overload working state of the cable and the electric energy consumption of the cable in the normal working state; step 5): stopping the power supply to the cable when the cable is in the overload working state; the beneficial effect of the invention: the heating cable is controlled by comparing and detecting the heat collection temperature and electric energy consumption of the cable in the two working states.

Description

Technical Field

[0001] The invention belongs to the technical field of heating cable protection control, and in particular relates to a control system and a control method for cable heating protection. Background Art

[0002] Nowadays, cables have become a necessity in the electrical industry. However, in the process of using these cables, the following situations are often encountered: the cables are overloaded and overheated during the production process, the use of electricity is unsafe, and even burning and catching fire; even fire and other safety accidents and hidden dangers may occur, especially when high-power electrical components are used, the cables are subjected to external overload electricity, or the cables themselves age over time, causing short circuits in the internal circuits and high currents that cause the cables to heat up or even catch fire, and even cause fire safety hazards.

[0003] Heating cables use electricity as energy and use alloy resistance wires to generate heat to achieve the effect of heating or insulation. During the operation of the heating cable, insulation damage may occur due to mechanical damage, insulation aging and deterioration, chemical corrosion, overvoltage and other reasons, resulting in short-circuit failures, which will cause great harm to the heating cable itself and the power system. In order to prevent the harm from further expanding, the heating cable needs to be equipped with a corresponding fault protection circuit to ensure the safe operation of the heating cable and the power system. Once a heating cable fails, it may cause a large short-circuit current to flow through the cable. If the short-circuit current is too large or lasts for a long time, the cable temperature will exceed the limit temperature, which may cause irreversible damage such as cable burns. Summary of the invention

[0004] The technical problem to be solved by the present invention is how to realize fault protection of the heating cable to ensure the safe operation of the heating cable and the power system. The present invention provides a control system and a control method for cable heating protection. By comparing and detecting the heat collection temperature and the power consumption of the cable in two working states, it can be known that as long as the cable is in an overload working state, the power supply to the cable is stopped, and the heating cable can be controlled.

[0005] In order to achieve the above object, the present invention is implemented by the following technical solutions:

[0006] A control method for cable heating protection comprises the following steps:

[0007] Step 1): temperature detection, detecting the heat collection temperature of the cable; wherein, the heat collection temperature of the cable in an overload working state and the heat collection temperature of the cable in a normal working state are detected respectively in the length direction of the cable by using a temperature collection method;

[0008] Step 2): The heat collection temperature detected when the cable is in an overload working state is compared with the heat collection temperature when the cable is in a normal working state by using a time period temperature method, and the heat collection temperature difference between the two working states is compared by using a temperature difference analysis method;

[0009] Step 3): Electric energy calculation, calculating the electric energy consumption of the cable; wherein the electric energy consumption of the cable is calculated respectively when the cable is in an overload working state and when the cable is in a normal working state;

[0010] Step 4): Calculate the heat utilization rate by using the heat loss method according to the power consumption of the cable when the cable is in an overloaded working state and the power consumption of the cable when the cable is in a normal working state;

[0011] Step 5): When the cable is in an overload working state, stop supplying power to the cable.

[0012] Optionally, in step 1), temperature detection is performed on all temperature concentration sections on the entire cable in the length direction of the cable to detect the heat collection temperature of the cable.

[0013] Furthermore, the temperature collection method adopts the following formula (1):

[0014] (1);

[0015] (2);

[0016] In formula (1), is the heat collection temperature of a certain temperature concentration section on the whole cable, i is the serial number of a certain temperature concentration section, N is the total number of temperature concentration sections on the whole cable, is the average collector temperature of the entire cable, is the correction factor for the temperature concentration section on the entire cable, It is the average heat collection temperature corrected for the temperature concentration section of the entire cable;

[0017] In formula (2), The length of a temperature concentration section on the entire cable, L is the length of the entire cable, is the ratio of the length of multiple temperature concentration sections to the length of the entire cable, 0< ≤1; The value of depends on the number of N. The larger the number of N, the The closer to 1; = 1, then the corrected average heat collection temperature of the temperature concentration section on the entire cable is the average heat collection temperature of the entire cable; 0< <1, then the corrected average heat collection temperature of the temperature concentration section on the entire cable There is a difference with the average collector temperature over the entire cable.

[0018] Optionally, in step 2), the time period temperature method is the following formula (3):

[0019] (3);

[0020] in, is the average collector temperature when the cable is in overload working condition, is the average collector temperature at the jth moment when the cable is in overload working state, is the temperature change state of the average collector temperature from the 1st moment to the jth moment when the cable is in overload working state, t is the time period from the 1st moment to the jth moment, is the temperature change state of the average collector temperature from the first moment to the jth moment when the cable is in overload working state within the time period t, AVG 1 [·] is the weighted average collector temperature calculation function from the first moment to the jth moment when the cable is in overload working state, AVG 1 [·] Calculate the weighted average collector temperature of the average collector temperatures at j moments;

[0021] is the average heat collection temperature when the cable is in normal working condition, is the average collector temperature at the jth moment when the cable is in normal working condition, is the temperature change state of the average heat collection temperature from the first moment to the jth moment when the cable is in normal working condition, t is the time period from the first moment to the jth moment, is the temperature change state of the average collector temperature from the first moment to the jth moment when the cable is in normal working state within the time period t, AVG 2 [·] is the weighted average heat collection temperature calculation function from the first moment to the jth moment when the cable is in normal working condition, AVG 2 [·] Calculate the weighted average collector temperature of the average collector temperatures at j moments;

[0022] It is the ratio of the weighted average collector temperature of the cable in the overload working state within the time period t to the weighted average collector temperature of the cable in the normal working state within the time period t.

[0023] Furthermore, the temperature difference analysis method analyzes the difference in collector temperature between the cable overload working state and the cable normal working state, using the following formula (4):

[0024] (4);

[0025] in, It is the difference between the weighted average heat collection temperature from the 1st moment to the jth moment when the cable is in overload working state and the weighted average heat collection temperature from the 1st moment to the jth moment when the cable is in normal working state.

[0026] Optionally, in step 3), the power consumption of the cable is detected using the following formula (5):

[0027] (5);

[0028] (6);

[0029] In formula (5), The voltage that energizes the cable, is the average current flowing through the cable, Indicates that the cable is in different working states. It is the average current of the cable when it is in different working conditions. is the time period during which the cable is energized, It is the power consumption of the cable in different working states;

[0030] In formula (6), is the current flowing through the cable at the jth moment, is the sum of the currents of the cable from the first moment to the jth moment. It is the average current of the cable during the cable power-on time period t.

[0031] Furthermore, the power consumption of the cable is detected when the cable is in an overload working state and the power consumption of the cable is detected when the cable is in a normal working state, using formula (7) and formula (8) respectively:

[0032] (7);

[0033] (8);

[0034] In formula (7), The cable is in an overloaded working state; is the power consumption of the cable when the cable is in overload working state; in formula (8), The cable is in normal working condition; It is the power consumption of the cable when it is in normal working condition;

[0035] The voltage of the cable when it is overloaded and in normal working state The same, the power-on time period t of the cable is the same.

[0036] Optionally, in step 4), the heat loss method is used to calculate the heat utilization rate, using the following formula (9):

[0037] (9);

[0038] in, It is the electric energy heat utilization rate of the electric energy consumption of the cable when the cable is in normal working state relative to the electric energy consumption of the cable when the cable is in overload working state.

[0039] A control system for cable heating protection, used for a control method for cable heating protection.

[0040] Beneficial effects of the present invention:

[0041] The present invention detects the heat collection temperature of the cable when the cable is in an overload working state and the heat collection temperature of the cable when the cable is in a normal working state; compares the heat collection temperature of the cable when the cable is in an overload working state and the heat collection temperature of the cable when the cable is in a normal working state, and compares the difference in the heat collection temperature under the two working states; detects the electric energy consumption of the cable when the cable is in an overload working state and when the cable is in a normal working state, and through the comparison and detection of the heat collection temperature and the electric energy consumption of the cable in the two working states, it can be known that as long as the cable is in an overload working state, the power supply to the cable is stopped, thereby controlling the heating cable. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0043] Figure 1 It is a schematic diagram of the system structure of the present invention;

[0044] Figure 2 It is a schematic diagram of the workflow of the present invention. DETAILED DESCRIPTION

[0045] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0046] Example 1

[0047] like Figure 1 As shown, this embodiment provides a control system for cable heating protection, including: a temperature detection module, a temperature comparison module, an electric energy calculation module, a heat loss calculation module and a control module.

[0048] The temperature detection module is used to detect the heat collection temperature when the cable is in an overload working state and the heat collection temperature when the cable is in a normal working state, and collect the heat collection temperatures in the two working states (a connector detects or collects the heat collection temperature when the cable is in an overload working state, b connector detects or collects the heat collection temperature when the cable is in a normal working state);

[0049] The temperature comparison module is used to compare the heat collection temperature when the cable is in an overload working state and the heat collection temperature when the cable is in a normal working state, and to compare the difference between the heat collection temperatures under the two working states;

[0050] The electric energy calculation module is used to calculate the electric energy consumption of the cable when the cable is in an overload working state and when the cable is in a normal working state;

[0051] The heat loss calculation module can calculate the heat utilization rate;

[0052] The control module is used to control the power supply of the cable. As long as the cable is in an overload working state, the power supply to the cable is stopped, that is, the power supply to the cable in the overload working state is stopped, so that the heating cable is controlled.

[0053] The actuator can be a circuit switch, that is, an intelligent control switch.

[0054] Figure 1 The various modules of a control system for cable heating protection are connected by circuits.

[0055] in addition, Figure 1 There are two detection lines on the left side of the temperature detection module in order to simultaneously detect the collector temperature when the cable is in overload working state and the collector temperature when the cable is in normal working state. The two detection lines are respectively connected to the cable in the overload working state and the cable in the normal working state.

[0056] Example 2

[0057] Based on Example 1, Figure 2 As shown, this embodiment provides a control method for cable heating protection, including the following steps:

[0058] Step 1): temperature detection, detecting the heat collection temperature of the cable; wherein, the heat collection temperature when the cable is in an overload working state (exceeding the rated working current of the cable) and the heat collection temperature when the cable is in a normal working state (rated working current of the cable) are detected respectively in the length direction of the cable by using the temperature heat collection method;

[0059] Step 2): The heat collection temperature detected when the cable is in an overload working state is compared with the heat collection temperature when the cable is in a normal working state by using a time period temperature method, and the heat collection temperature difference between the two working states is compared by using a temperature difference analysis method;

[0060] Step 3): Electric energy calculation, calculating the electric energy consumption of the cable; wherein the electric energy consumption of the cable is calculated respectively when the cable is in an overload working state and when the cable is in a normal working state;

[0061] Step 4): Calculate the heat utilization rate by using the heat loss method according to the power consumption of the cable when the cable is in an overloaded working state and the power consumption of the cable when the cable is in a normal working state;

[0062] Step 5): When the cable is in an overload working state, stop supplying power to the cable.

[0063] Specifically, in step 1), temperature detection is performed on all temperature concentration sections on the entire cable in the length direction of the cable to detect the heat collection temperature of the cable.

[0064] Furthermore, the temperature collection method uses the following formula (1):

[0065] (1);

[0066] (2);

[0067] In formula (1), is the heat collection temperature of a certain temperature concentration section on the whole cable, i is the serial number of a certain temperature concentration section, N is the total number of temperature concentration sections on the whole cable, is the average collector temperature of the entire cable, is the correction factor for the temperature concentration section on the entire cable, It is the average heat collection temperature corrected for the temperature concentration section of the entire cable;

[0068] In formula (2), The length of a temperature concentration section on the entire cable, L is the length of the entire cable, is the ratio of the length of multiple temperature concentration sections to the length of the entire cable, 0< ≤1; The value of depends on the number of N. The larger the number of N, the The closer to 1; =1, then the corrected average heat collection temperature of the temperature concentration section on the entire cable is the average heat collection temperature of the entire cable; 0< <1, then the corrected average heat collection temperature of the temperature concentration section on the entire cable There is a difference with the average collector temperature over the entire cable.

[0069] The entire cable is divided into multiple sections along the length of the cable, and the multiple sections are temperature concentration sections. The temperature of each temperature concentration section on the entire cable is detected. The temperature of each temperature concentration section may be the same or different. The temperature detection of each temperature concentration section can be used to know the heat collection temperature of the entire cable, that is, the temperature of each temperature concentration section is summed up and then divided by the number of temperature concentration sections or the total number of temperature concentration sections to obtain the average heat collection temperature of the entire cable.

[0070] The correction coefficient of the temperature concentration section on the entire cable in formula (2) can be used to determine the corrected average heat collection temperature on the entire cable. =1, then the corrected average heat collection temperature of the temperature concentration section on the entire cable is the average collector temperature over the entire cable.

[0071] Specifically, in step 2), the time period temperature method is the following formula (3):

[0072] (3);

[0073] in, is the average collector temperature when the cable is in overload working condition, is the average collector temperature at the jth moment when the cable is in overload working state, is the temperature change state of the average collector temperature from the 1st moment to the jth moment when the cable is in overload working state, t is the time period from the 1st moment to the jth moment, is the temperature change state of the average collector temperature from the first moment to the jth moment when the cable is in overload working state within the time period t, AVG 1 [·] is the weighted average collector temperature calculation function from the first moment to the jth moment when the cable is in overload working state, AVG 1 [·] Calculate the weighted average collector temperature of the average collector temperature at j moments; AVG 1 [·] is the weighted average heat collection temperature of the j-th moment obtained by summing up the average heat collection temperature at each moment from the 1st moment to the j-th moment when the cable is in overload working state and then dividing it by the number of moments from the 1st moment to the j-th moment.

[0074] is the average heat collection temperature when the cable is in normal working condition, is the average collector temperature at the jth moment when the cable is in normal working condition, is the temperature change state of the average heat collection temperature from the first moment to the jth moment when the cable is in normal working condition, t is the time period from the first moment to the jth moment, is the temperature change state of the average collector temperature from the first moment to the jth moment when the cable is in normal working state within the time period t, AVG2 [·] is the weighted average heat collection temperature calculation function from the first moment to the jth moment when the cable is in normal working condition, AVG 2 [·] Calculate the weighted average collector temperature of the average collector temperature at j moments; AVG 2 [·] is the weighted average heat collection temperature of the j-th moment obtained by summing up the average heat collection temperatures at each moment from the 1st moment to the j-th moment when the cable is in normal working condition and then dividing it by the number of moments from the 1st moment to the j-th moment.

[0075] It is the ratio of the weighted average collector temperature of the cable in the overload working state within the time period t to the weighted average collector temperature of the cable in the normal working state within the time period t.

[0076] Furthermore, the temperature difference analysis method is used to analyze the difference in collector temperature between the cable overload working state and the cable normal working state, using the following formula (4):

[0077] (4);

[0078] in, It is the difference between the weighted average heat collection temperature from the 1st moment to the jth moment when the cable is in overload working state and the weighted average heat collection temperature from the 1st moment to the jth moment when the cable is in normal working state.

[0079] Specifically, in step 3), the power consumption of the cable is calculated using the following formula (5):

[0080] (5);

[0081] (6);

[0082] In formula (5), The voltage at which the cable is energized, is the average current flowing through the cable, Indicates that the cable is in different working states. It is the average current of the cable when it is in different working conditions. is the time period during which the cable is energized, It is the power consumption of the cable in different working states;

[0083] In formula (6), is the current flowing through the cable at the jth moment, is the sum of the currents of the cable from the first moment to the jth moment. It is the average current of the cable during the cable power-on time period t.

[0084] Furthermore, the power consumption of the cable when the cable is in an overloaded working state and the power consumption of the cable when the cable is in a normal working state are calculated using formula (7) and formula (8) respectively:

[0085] (7);

[0086] (8);

[0087] In formula (7), The cable is in an overloaded working state; is the power consumption of the cable when the cable is in overload working state; in formula (8), The cable is in normal working condition; It is the power consumption of the cable when it is in normal working condition;

[0088] The voltage of the cable when it is overloaded and in normal working state The same is the rated voltage of the cable , the power-on time period t of the cable is the same.

[0089] Furthermore, in step 4), the heat loss method is used to calculate the heat utilization rate, using the following formula (9):

[0090] (9);

[0091] in, It is the electric energy heat utilization rate of the electric energy consumption of the cable when the cable is in normal working state relative to the electric energy consumption of the cable when the cable is in overload working state.

[0092] Example 3

[0093] Based on Examples 1-2, the present invention detects the heat collection temperature of the cable when the cable is in an overload working state and the heat collection temperature of the cable when the cable is in a normal working state; compares the heat collection temperature of the cable when the cable is in an overload working state and the heat collection temperature of the cable when the cable is in a normal working state, and compares the difference in heat collection temperature between the two working states; detects the electric energy consumption of the cable when the cable is in an overload working state and when the cable is in a normal working state, and through the comparison and detection of the heat collection temperature and the electric energy consumption of the cable in the two working states, it can be known that as long as the cable is in an overload working state, the power supply to the cable is stopped, thereby controlling the heated cable.

[0094] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope of the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A control method for cable heating protection, characterized in that: The steps include: Step 1): temperature detection, detecting the heat collection temperature of the cable; wherein the heat collection temperature of the cable in an overload working state and the heat collection temperature of the cable in a normal working state are detected respectively in the length direction of the cable by using a temperature collection method; Step 2): The heat collection temperature detected when the cable is in an overload working state is compared with the heat collection temperature when the cable is in a normal working state by using a time period temperature method, and the heat collection temperature difference between the two working states is compared by using a temperature difference analysis method; Wherein, in the step 2), the time period temperature method is the following formula (3): (3)； in, is the average collector temperature when the cable is in overload working condition, is the average collector temperature at the jth moment when the cable is in overload working state, is the temperature change state of the average collector temperature from the 1st moment to the jth moment when the cable is in overload working state, t is the time period from the 1st moment to the jth moment, is the temperature change state of the average collector temperature from the 1st moment to the jth moment when the cable is in overload working state within the time period t, AVG1[·] is the weighted average collector temperature calculation function from the 1st moment to the jth moment when the cable is in overload working state, and AVG1[·] calculates the weighted average collector temperature of the average collector temperature at j moments; is the average heat collection temperature when the cable is in normal working condition, is the average collector temperature at the jth moment when the cable is in normal working condition, is the temperature change state of the average heat collection temperature from the first moment to the jth moment when the cable is in normal working condition, t is the time period from the first moment to the jth moment, is the temperature change state of the average collector temperature from the first moment to the jth moment when the cable is in normal working condition within the time period t, AVG2[·] is the weighted average collector temperature calculation function from the first moment to the jth moment when the cable is in normal working condition, and AVG2[·] calculates the weighted average collector temperature of the average collector temperatures at j moments; It is the ratio of the weighted average heat collection temperature of the cable in the overload working state within the time period t to the weighted average heat collection temperature of the cable in the normal working state within the time period t; The temperature difference analysis method analyzes the difference in heat collection temperature between the cable overload working state and the cable normal working state, using the following formula (4): (4)； in, It is the difference between the weighted average heat collection temperature from the first moment to the jth moment when the cable is in overload working state and the weighted average heat collection temperature from the first moment to the jth moment when the cable is in normal working state; Step 3): Electric energy calculation, calculating the electric energy consumption of the cable; wherein the electric energy consumption of the cable is calculated respectively when the cable is in an overload working state and when the cable is in a normal working state; Step 4): Calculate the heat utilization rate by using the heat loss method according to the power consumption of the cable when the cable is in an overloaded working state and the power consumption of the cable when the cable is in a normal working state; Step 5): When the cable is in an overload working state, stop supplying power to the cable.

2. A control method for cable heating protection according to claim 1, characterized in that: In the step 1), temperature detection is performed on all temperature concentration sections on the entire cable in the length direction of the cable to detect the heat collection temperature of the cable.

3. A control method for cable heating protection according to claim 2, characterized in that: The temperature collection method adopts the following formula (1): (1)； (2)； In formula (1), is the heat collection temperature of a certain temperature concentration section on the whole cable, i is the serial number of a certain temperature concentration section, N is the total number of temperature concentration sections on the whole cable, is the average collector temperature of the entire cable, is the correction factor for the temperature concentration section on the entire cable, It is the average heat collection temperature corrected for the temperature concentration section of the entire cable; In formula (2), The length of a temperature concentration section on the entire cable, L is the length of the entire cable, is the ratio of the length of multiple temperature concentration sections to the length of the entire cable, 0< ≤1; The value of depends on the number of N. The larger the number of N, the The closer to 1; = 1, then the corrected average heat collection temperature of the temperature concentration section on the entire cable is the average heat collection temperature of the entire cable; 0< <1, then the corrected average heat collection temperature of the temperature concentration section on the entire cable There is a difference with the average collector temperature over the entire cable.

4. A control method for cable heating protection according to claim 1, characterized in that: In step 3), the power consumption of the cable is detected using the following formula (5): (5)； (6)； In formula (5), The voltage at which the cable is energized, is the average current flowing through the cable, Indicates that the cable is in different working states. It is the average current of the cable when it is in different working conditions. is the time period during which the cable is energized, It is the power consumption of the cable in different working states; In formula (6), is the current flowing through the cable at the jth moment, is the sum of the currents of the cable from the first moment to the jth moment. It is the average current of the cable during the cable power-on time period t.

5. A control method for cable heating protection according to claim 4, characterized in that: The power consumption of the cable is detected when the cable is in an overload working state and the power consumption of the cable is detected when the cable is in a normal working state, using formula (7) and formula (8) respectively: (7)； (8)； In formula (7), The cable is in an overloaded working state; It is the power consumption of the cable when the cable is in overload working state; In formula (8), The cable is in normal working condition; It is the power consumption of the cable when it is in normal working condition; The voltage of the cable when it is overloaded and in normal working state The same, the power-on time period t of the cable is the same.

6. A control method for cable heating protection according to claim 5, characterized in that: In step 4), the heat loss method is used to calculate the heat utilization rate, using the following formula (9): (9)； in, It is the electric energy heat utilization rate of the electric energy consumption of the cable when the cable is in normal working state relative to the electric energy consumption of the cable when the cable is in overload working state.

7. A control system for cable heating protection, characterized in that: Used to execute a control method for cable heating protection according to any one of claims 1-6.

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