CN111525498A - Overload protection device and method - Google Patents

Abstract

The invention discloses an overload protection device, which comprises: the parameter setting unit is used for setting the nominal limit temperature of the benchmark power assembly positioned in the power utilization loop; a control condition generating unit for generating a plurality of control conditions representing the abnormal working temperature of the benchmark power component according to the nominal limit temperature; the temperature collecting unit is used for receiving the working temperature information; and the operation output unit is used for calculating the working temperature rise index according to the working temperature information and sending out protection information for executing specific protection actions when the working temperature rise index meets one of the control conditions. Therefore, the overload protection device and method for obtaining the optimal overload protection can be obtained.

Description

Overload protection device and method

【Technical field】

The present invention relates to a protection device and method for preventing circuit overload; in particular, to an intelligent overload protection device that allows users to set various protection specifications by themselves, and can perform adaptive protection for power circuits Protection device and method.

【Previous Technology】

In various electrical circuits, once the power supply is unstable, there is a surge or excessive current, or the components are abnormal or the load is adjusted too large, so that the circuit current is too large, and the load exceeds the load of some circuit components. May cause malfunction or burnout of circuit devices. Therefore, overcurrent protection mechanisms, or overload protection mechanisms, are ubiquitous in circuit design.

In the overcurrent and overload protection mechanism, the temperature sensor is a commonly used detection component, especially the negative temperature coefficient (NTC) temperature sensor, which is usually installed on the circuit load to detect whether the load is overheated. Once overheated, the circuit switch is controlled by feedback to automatically reduce or close the load current of the circuit. In the prior art, when the overheating exceeds a certain temperature, a warning is issued, the current is adjusted, or the power is turned off, and the load current is adjusted according to the temperature rising slope of the load to determine whether the load is operating normally. For example, those disclosed in Chinese Patent No. CN103699152, Patent No. CN105444213, etc.

However, even though a variety of protection methods are disclosed in the prior art, they only think of monitoring the load and then performing automatic regulation. There is no one that can comprehensively consider all the components of the circuit, or how to take the overall consideration to obtain The most appropriate protection for overload protection. Existing fuses or breakers, for inrush currents from the outside and overcurrents caused by internal component failures, although they try to provide the best protection, they often fail to take care of one or the other. Either too much or not enough, and it is difficult for designers to choose the specifications that provide the best protection.

[Content of the invention]

Therefore, the purpose of the present invention is to provide an intelligent circuit breaker that can achieve the best protection, and can be set up by the user according to the power circuit to be protected, and can further replace the conventional circuit breaker. Type overload protection device and method.

In order to achieve the purpose of the present invention, the present invention provides an overload protection device, comprising:

A parameter setting unit for setting the nominal limit temperature of the benchmark power component located in the electrical circuit, and the benchmark power component has an operating temperature caused by the working current passing through one of them;

a control condition generating unit, configured to generate a plurality of control conditions representing the abnormal working temperature of the benchmark power component according to the nominal limit temperature;

a temperature collection unit for receiving the operating temperature information of the benchmark power component; and,

The operation output unit calculates the working temperature rise index according to the working temperature information, and is used for sending out protection information for executing a specific protection action when the working temperature rise index meets one of the control conditions.

Further, the benchmark power component disclosed in the present invention is the one that reaches its limit temperature the fastest among all the power components of the electric circuit when the operating current exceeds the rated load, and its limit temperature is taken as the nominal limit temperature . The benchmark power component disclosed in the present invention can also be one of the inlet components of the electricity consumption circuit. All power components in the electricity consumption circuit have the weakest power that reaches the limit temperature the fastest when the working current exceeds the rated load. component, and the nominal limit temperature is the working temperature of the benchmark power component when the weakest power component is at its limit temperature.

Further, the control condition generation unit is used to set the N-order upper limit temperature rise control index as the control conditions according to the nominal limit temperature, the protection starting temperature, the time difference between the extreme upper limit, and the time difference between the extreme lower limit, and N is A positive integer; and is used to set an N-order control index as a control condition according to a margin R and each step-by-step upper-limit temperature-rise control index of the N-order upper-limit temperature-rise control index, and each-order control index includes the step-by-step upper limit temperature rise control index The upper limit temperature rise control index, and the step-by-step control point calculated from the step-by-step upper limit temperature rise control index and the margin R; moreover, the margin R is the setting of a specific range in advance for one of temperature and time. Quantitative, the control points include one of the control temperature and the control time

The present invention also provides an overload protection method, which includes:

The parameter setting step is used to set the nominal limit temperature of the benchmark power component located in the power consumption circuit, and the benchmark power component has a working temperature caused by passing one of the working currents;

The control condition generating step is used for generating a plurality of control conditions representing the abnormal working temperature of the benchmark power component according to the nominal limit temperature;

a temperature collection step for receiving the operating temperature information of the benchmark power component; and,

The operation and output step calculates the working temperature rise index according to the working temperature information, and is used for sending out protection information for executing a specific protection action when the working temperature rise index meets one of the control conditions.

With the above invention, the best overload protection can be made for the electrical circuit, and since the user can set and change the protection conditions by himself or herself according to the electrical circuit to be protected, standard components can be used to adapt to the The most adaptive protection can be set according to the conditions of various power circuits, and since it can quickly respond to the conditions of the power circuits, it can further replace the conventional circuit breaker, so an intelligent overload protection device and method can be obtained. The device disclosed in the present invention can take into account the overcurrent from the inside or the outside, has the advantages of a fuse, but no/less its disadvantages, and has the function of a circuit breaker protector but improves its shortcoming of slow response, so this system should be able to Replaces most fuse or circuit breaker applications, especially those that generate heat and frequently need to be started/shut down.

In order to make the above-mentioned and other objects, features and advantages of the present invention more clearly understood, preferred embodiments are hereinafter described in detail in conjunction with the accompanying drawings. However, those with ordinary knowledge in the field of the present invention should understand that the detailed description and the specific embodiments for implementing the present invention are only used to illustrate the present invention, and are not intended to limit the scope of the patent application of the present invention.

[Simple description of the diagram]

FIG. 1 shows a schematic diagram of the composition and a first application example of the overload protection device according to various embodiments of the present invention.

FIG. 2 shows a schematic diagram of a second application example of the overload protection device according to various embodiments of the present invention.

FIG. 3 shows a schematic diagram of the weakest component selection according to an embodiment of the present invention.

FIG. 4 shows a schematic diagram of an example of generating control conditions according to an embodiment of the present invention.

FIG. 5 shows a schematic diagram of a control point generation example according to an embodiment of the present invention.

FIG. 6 shows a schematic diagram of a protection flow of an overload protection method according to an embodiment of the present invention.

【Symbol Description】

1 electrical circuit

11 switches

12 Fuses

13 load

14 Three-gate switch/regulator

15 Resistors

16 Manual load regulator

100,101,102 Overload protection device

110 Parameter setting unit

120 Control Condition Generation Unit

130 temperature collection unit

140 Computational output unit

150 Temperature Sensing Components

160 Regulators

170 Warning devices

S1,S2,S3,S4,S5,S6,S7, steps

[implementation]

Hereinafter, the preferred embodiments according to the present invention are listed with the drawings to illustrate the components and steps of the overload protection device and method disclosed in the present invention, as well as the achieved effects. However, the relevant components, dimensions and settings of the overload protection device shown in the drawings are only used to illustrate the technical features of the present invention, but not to limit the present invention.

FIG. 1 shows a schematic diagram of the composition and a first application example of an overload protection device 100 according to a first embodiment of the present invention. The overload protection device 100 mainly includes: a parameter setting unit 110 , a control condition generating unit 120 , a temperature collecting unit 130 , and an arithmetic output unit 140 . FIG. 1 also shows some components of the electrical circuit 1 matched with the overload protection device 100 , including a load 13 for measuring the operating temperature and serving as a benchmark power component, and a resettable regulating device 14 for regulating the operating current. The load 13 and the control device 14 have an operating temperature caused by the passing of one of the operating currents, and the maximum allowable operating temperature that can operate normally, which is generally referred to as a rated temperature, and can also be referred to as a limit temperature; however, the present invention refers to the The limit temperature is not limited to this.

The parameter setting unit 110 is used to set the nominal limit temperature TM _RM of the benchmark power component as the temperature source of the temperature collection unit 130 . In the example shown in FIG. 1 , the load 13 is used as the benchmark power component. The selection of , as well as the setting details of the nominal limit temperature TM _RM , are described later. The control condition generating unit 120 is used for generating a plurality of control conditions representing the abnormal working temperature of the benchmark power component according to the nominal limit temperature TM _RM , which can be automatically generated or generated by setting; the The control conditions can generally be the control temperature, the control time, the temperature rise control index of the working temperature within a period of time, or a single or composite condition of at least one of the three, the details of which will be described in detail later. The temperature collection unit 130 is used for receiving the operating temperature information from the benchmark power components. The arithmetic output unit 140 is used for calculating the working temperature rise index according to the working temperature information received by the temperature collecting unit 130, and is used for sending a message to execute a specific protection action when the working temperature rise index meets one of the control conditions protection information; details about the temperature rise control index and the specific protection action are also described later.

FIG. 1 also shows a schematic composition diagram of an overload protection device 101 according to a second embodiment of the present invention. In addition to the overload protection device 100, the overload protection device 101 shown in the second embodiment also includes a temperature sensing component 150, and a control device 160 disposed in the power consumption circuit 1 as the power component therein, that is, the power consumption The regulating device 14 in the circuit 1 also serves as the regulating device 160 of the overload protection device 101 . The temperature sensing component 150 is attached to the load 13 to sense its working temperature and send the working temperature information. The control device 160 is arranged in the power consumption circuit 1 to receive the protection signal sent by the arithmetic output unit 140, and adjust the power supply condition of the power consumption circuit 1, and the adjustment includes cutting off and adjusting the power supply size, which can be a TRIAC, etc. Three-gate switch, bridge rectifier and other two-gate bodies, or others.

FIG. 1 also shows a schematic composition diagram of an overload protection device 102 according to a third embodiment of the present invention. In addition to the overload protection device 101 , the overload protection device 102 shown in the third embodiment also includes a warning device 170 . Of course, in a modified example, the overload protection device 102 disclosed in the third embodiment may also include a warning device 170 in addition to the overload protection device 100 . The warning device 170 is used for receiving the protection signal sent by the arithmetic output unit 140 and sending a warning accordingly. The warning can be any sound, light, information or action, and different warning methods can be given according to the different protection information sent due to different control conditions.

The overload protection devices mentioned in the above three embodiments all contain the main core technology of the present invention, but there are different implementation modes according to different components. For example, the overload protection device 100 may be a single-chip type such as an MCU, which may have, for example, 6 pins for power input, parameter setting input, and protection information output. The modification of the above-mentioned overload protection device 102 may also be a single-chip type such as an MCU, which may have, for example, 8 pins for adding the output of the warning system. When the overload protection device 100 is actually used in conjunction with the electrical circuit 1 , it can be the overload protection device 101 shown in the second embodiment including the temperature sensing component 150 and the regulating device 160 . When actually applied to the electrical circuit 1 and the warning device 170 is added, it is the implementation of the overload protection device 102 .

FIG. 2 shows another second application embodiment of the overload protection device 100 / 101 used in the electrical circuit 1 . The electrical circuit 1 is powered by an alternating current power supply AC, but not limited to this, and mainly includes a switch 11, a fuse 12 serving as a subsequent overcurrent circuit breaker, a load 13, and as specific examples of the aforementioned regulating devices 14, 160 are marked with A triac switch (TRIAC) 14 of the same reference numerals, a resistor 15 representing any other possible component in the electrical circuit 1, and a manual load regulator 16. Among them, the load 13, the three-gate switch 14, the resistor 15, and the load regulator 16 all have impedances, and when the electrical circuit 1 is working, there is a working current passing through, so they are all power components in this case, and each has the same power as before. The working temperature and limit temperature mentioned above. In addition, the wires or heat pads that generate heat are also regarded as the power components in the present invention, so the so-called power components can also include power parts.

The electrical circuit 1 usually has a rated load, which is used to indicate the maximum safe load value of the electrical circuit 1 under normal operation, which can be a power value or a current value, such as 2 amperes. The three-gate switch 14 can be driven by any environment or the detection and control circuit (not shown) of the electrical circuit 1 itself, and automatically adjust whether or not the current in the electrical circuit 1 passes or not, so it can be used as an overcurrent circuit breaker protection The device can also be used as a load adjustment component. Although this function is known, it has not been able to provide the best circuit breaker protection without cooperating with the overall technical idea disclosed in the present invention. The resistor 15 can be used as a current limiter or a current sensor, etc., and other components mentioned herein are not limited to resistors. In addition, the power circuit 1 may have another power component (not shown) connected in parallel with the load 13 , under which the three-gate switch 14 is equivalent to controlling the series/parallel power supply of the entire power circuit 1 , so the three-gate switch 14 It can be said to be the inlet component of the electrical circuit 1, and any overload current of the electrical circuit 1 will pass through the three-gate switch 14, so it is called this.

In addition, in the application example shown in FIG. 2 , the object measured by the temperature sensing element 150 is the three-gate switch 14 serving as the inlet element, not the load 13 in the application example shown in FIG. 1 . This represents the benchmark power component disclosed in the present invention as the source of operating temperature information, which may be the inlet component 14 or the load 13 . According to the different properties of the benchmark power components, the aforementioned nominal limit temperature TM _RM will have different setting principles, which will be further explained below.

Whether the inlet component 14 or the load 13 is selected as the benchmark power component, the weakest component in the electrical circuit 1 must be selected first. This can be done, for example, by operating the electrical circuit 1 at a normal temperature, and at various escalating currents exceeding the rated load, for example, every 1 ampere liter, from the various power components of the electrical circuit, selecting the most The one that is about to reach its limit temperature or specific regulatory temperature is the weakest component in this electrical circuit 1. Fig. 3 shows a schematic diagram of selecting the weakest component according to the above method, that is, it shows that when the ambient temperature is 40°C, and the power supply circuit 1 is greater than the rated load but still can operate normally under the maximum working current, the The temperature rise curves 13S, 14S, 15S, and 16S of the power components 13, 14, 15, and 16 in the electrical circuit 1; the inflection point of the curve represents the temperature drop after the power is turned off. Comparing the curves, it can be concluded that the power component 13 reaches its extreme temperature, eg, 125 degrees, the fastest, so the power component 13 , that is, the load 13 , is the weakest component of the electrical circuit 1 . Also, in this example, although the load 13 is the weakest component, it may actually be other components such as the resistor 15, depending on the actual materials. In a modified example, the working current of the selected weakest component may also be an intermittent constant current.

After the weakest component is selected, the nominal limit temperature TM _RM can be set according to the choice of the benchmark power component. In the application example shown in FIG. 1 , the temperature sensing component 150 directly detects the operating temperature of the load 13 where the weakest component is located, and the weakest component is used as the benchmark power component. At this time, the nominal limit temperature TM _RM is set to Set as the limit temperature of load 13. In the application example shown in FIG. 2 , the temperature sensing element 150 does not measure the load 13 where the weakest element is located, but measures the three-gate switch 14 of the inlet element, which is used as a benchmark power element, and the nominal limit at this time is The temperature TM _RM is set as the relative operating temperature of the three-gate switch when the load 13 where the weakest component is located has reached its limit temperature. For the approach shown in FIG. 2 using the three-gate switch 14 of the inlet component as the benchmark power component, it is preferable when the weakest component is a large-area heating wire such as a heating pad, and it is difficult to predict the position of its weakest point, especially It can achieve better protection; in addition, when there are many shunts in the electrical circuit, it can also achieve better protection for the entire electrical circuit against inrush currents caused by abnormal damage to other components that are not the weakest.

Hereinafter, an example of generation of control conditions will be further described. According to the technical idea of the present invention, before generating the control conditions, in addition to the nominal limit temperature TM _RM which is input by the parameter setting unit 110 and adapts to the actual conditions of the electric circuit 1, the protection starting temperature TM _S is also required. , and an extremely upper time difference TP _M that represents the maximum evaluation time from the protection starting temperature to the temperature reaching the nominal limit temperature, and an extremely lower time difference TPs that represents the fastest response action of the overload protection device 100, so as to automatically generate multiple Control indicators as control conditions. However, the aforementioned protection starting temperature TM _S , the upper limit time difference _{T M} , and the lower limit time difference _{T S} can be set manually through the parameter setting unit 110 , or can be set automatically by the overload protection device 100 , or can be set automatically. Value. Therefore, the parameter setting unit 110 can not only set the nominal limit temperature TM _RM , but also set the protection starting temperature TM _S , the extremely upper time difference _{T M} , and the extremely lower time difference _{T S} .

If the protection starting temperature TM _S is automatically set by the overload protection device 100 , for example, the nominal limit temperature TM _RM set by the user can be reduced by a certain value, such as 40 degrees, and the protection starting temperature TM _S can be automatically obtained. . In addition, in a further embodiment, the specific value can also be changed according to the variable protection sensitivity level that the user wants to adopt for the overload protection device 100; for example, to be more sensitive and respond earlier, the specific value can be increased To 50 degrees, if you want a slower response, you can set this specific value to 20 degrees. The protection sensitivity level can also be set by the user via the parameter setting unit 110 . Alternatively, the protection starting temperature TM _S can be set so that, regardless of the nominal limit temperature TM _RM , it starts to calculate the working temperature for overload protection starting from, for example, 50 degrees. Also, in a preferred embodiment, the protection starting temperature TM _S is preferably input by the user via the parameter setting unit 110, and preferably the benchmark power component is when the power circuit 1 is at its rated load The temperature is taken as its protection starting temperature TM _S . In addition, the extreme upper limit time difference TP _M can be automatically set in addition to being input by the user, for example, the time length can be automatically set according to the inputted nominal limit temperature TM _RM . In a preferred embodiment, a fixed value is adopted, such as 30 minutes/1800 seconds. The minimum time difference _TPS can also be set according to the response speed of the device, or a fixed value can be adopted. For example, considering the response capability of the MCU, it can be set to 0.1 seconds; alternatively, it can be set to 0 seconds, which will not affect the following Protection capacity under regulated conditions.

With all parameters prepared, the control condition generation unit 120 can set an N-order upper limit temperature rise control index as the control condition according to the nominal limit temperature TM _RM and the protection starting temperature TM _S , where N is a positive integer, It can also be set for a machine, or set by the user through the parameter setting unit 110 . 4 is a schematic diagram showing an example of an N-order upper limit temperature rise control index generated by the control condition generating unit 120 . In this example, N is 7, and an arctangent of a temperature difference and a time difference is used as the temperature rise control index. Specifically, the control condition generating unit 120 is based on a maximum time difference _{TPM of, for example, 1800 seconds, a minimum time difference TPS of, for example, 0 seconds, and the nominal limit temperature TM RM ( for} example, 125 degrees) compared with The temperature difference of the protection starting temperature TM _S (for example, 95 degrees) is 30 degrees, in units of 10 seconds, and the arc tangent angle (arctan (30/180)) is taken to define the upper limit angle of the first order among the 7 orders, It is about 9.5 degrees; and according to the extreme lower time difference TP _S of 0 seconds, and the 30 degree temperature difference, take the arc tangent angle to define the seventh order extreme upper limit angle of the seventh order, which is 90 degrees; and with (the The seventh-order extreme upper-limit angle-the first-order upper-limit angle)/(7-1), as the range of the step-by-step angles of the (7-1) steps other than the first-order, which is about 13.4 degrees. In this way, when the range of each step angle of the 7 steps is accumulated in sequence, the upper limit angles of each step of the 7 steps can be obtained, for example: 9.5°, 22.9°, 36.3°, 49.7°, 63.1 °, 76.5°, and 90°; each step-by-step upper-limit temperature-rise control index of these N-step upper-limit temperature-rise control indicators refers to the above-mentioned step-by-step upper limit angle.

In addition, in the example shown in FIG. 4 , the arctangent angle is estimated from the temperature difference and the time difference as the temperature rise control index, but in a modification, the slope of the temperature difference and the time difference (same as the unit of 10 seconds) can also be used , as the upper limit temperature rise control index of each step, for example, take the slope 0.16 of the nominal limit temperature TM _RM and the extreme upper limit time difference TP _M as the first step, and then its multiples 0.32, 0.64, 1.28, 2.56, 5.12, and infinity, As the upper limit temperature rise control index of the 2nd to 7th stage. Therefore, the so-called temperature rise control index in the present invention may be an angle or a slope, etc., but is not limited to this. Moreover, by setting the nominal limit temperature TM _RM by the user, each point can be used as a control condition. The temperature rise control index of the upper limit of the order is obtained to obtain the most suitable protection for the electric circuit 1.

In addition, in FIG. 4 , in addition to showing each step-by-step upper limit temperature rise control index line based on the angle obtained from the marked limit temperature TM _RM , each step-by-step upper limit time is also shown. As shown in FIG. 4 , under the known upper limit temperature rise control index of each step and the nominal limit temperature TM _RM , the time difference TP _M of the extreme upper limit, the first-order upper limit angle tangent value and the upper limit of each order can be based on The ratio of the tangent value and the multiplication of the two can deduce the upper limit time difference of each stage, for example, 1800 seconds for the first stage, and 710 seconds for the upper limit time differences of the other 6 stages according to the above algorithm. , 408 seconds, 254 seconds, 152 seconds, 72 seconds, and 0 seconds.

With the time difference of the upper limit of each step, many control conditions can be further developed that can have different control points according to the control indicators of each step temperature rise. In detail, since the rated temperature given by each component manufacturer is generally only a nominal value, in fact, it may be worse or better due to various factors such as process or material. Compared with the above-mentioned nominal limit temperature TM _RM or the upper limit time difference of each stage, a margin R of a specific range in advance can make up for the difference, and different pre-control can be obtained for each stage of different temperature rises Time or control temperature as control point. Therefore, the control indexes of each level as the control conditions include each level of upper limit temperature rise control index, and each level of control points calculated from the level of the upper limit temperature rise control index and the margin R; and, The control points include one of the control temperature and the control time, and the margin R is a set amount in advance of a specific range for either the temperature or the time. When the margin R is a specific time, the control points will control the temperature according to different steps and have different values lower than the nominal limit temperature TM _RM , so that under the same lead time, according to different temperature rise exponents , to obtain different advance reaction temperatures.

Figure 5 shows a schematic diagram of obtaining different control points according to the upper limit temperature rise control index of each order shown in Figure 4 and the margin R, among which only the first and third order control points are taken as examples. As shown in Fig. 5, the unit of the margin R is set to time, and the margin time ΔT is set to 50 seconds. Based on the calculation of the control temperature of each stage, it can be deduced that the control temperature of the first stage is 124.5 degrees, The control temperature for the third stage is 121.5 degrees. Figure 5 is only a diagram to illustrate the technical idea, in fact, the value can be derived from the arithmetic formula, which are listed as follows:

1st stage: 95°C+ ^tan9.5 °x(180-5)=124.5°C

^2nd order: 95°C+tan22.9°x(71-5)=123°C

^3rd order: 95°C+tan36.3°x(40.8-5)=121.5°C

4th order: 95°C+ ^tan49.7 °x(25.4-5)=118.5°C

5th order: 95°C+ ^tan63.1 °x(15.2-5)=114.5°C

6th order: 95°C+ ^tan76.5 °x(7.2-5)=103.5°C

In the above example, except for the 7th stage, each stage has its control temperature as the control point (because the 7th stage is 90 degrees). After the control condition generation unit 120 completes the above control conditions, as long as the operation output unit 140 calculates the operating temperature information received by the temperature collection unit 130, including the temperature and the corresponding time, starting from the protection starting temperature _TMS After the working temperature rise index (in this case, it is the angle), compare the working temperature rise index with the N-order upper limit temperature rise control index, and then the temperature rise conformity order can be obtained, and then the temperature rise conformity order can be obtained. The control temperature is compared with the working temperature information, and if the working temperature is greater than the control temperature, the control device 160 performs an action of circuit breaker protection, thereby obtaining overload circuit breaker protection. Among them, in addition to the control point of the open circuit protection, different margins R can also be selected to obtain an earlier control point, and when the earlier control point is reached, the protection information for performing the warning action will be sent first; for example, the If the margin R is 100 seconds, a warning message will be sent when it reaches 123.6 degrees, for example. Therefore, there can be multiple control points at each level, and they can be used to perform one of various actions including warning or cutting off, or even adjusting the power supply of the power circuit.

In addition, regarding the warning, the extrapolation method can also be used to calculate the remaining time for the operating temperature information to continue to rise to the control temperature with the temperature rise corresponding to the level, and different protection information can be sent according to the difference of the remaining time. For example, if the remaining time is less than the upper limit time difference of the sixth stage, that is, falls within the range of the seventh stage, the control device 160 is immediately notified to turn off the electrical circuit 1, and the warning device 170 is allowed to perform a long-lasting red light. Warning; if it is greater than the upper limit time difference of the sixth level and less than, for example, 300 seconds, the warning device 170 will execute the protection action of flashing red light every 0.5 seconds; if it is greater than 300 seconds but less than 1800 seconds, execute the rapid flashing red every 2 seconds The action of the light; if it is longer than 1800 seconds, it will perform slow flashing every 5 seconds, etc., but if it still reaches the cut-off control temperature, it will still execute the cut-off action. If the temperature drops below the control temperature for some reason, the overload protection device automatically turns off the warning and stops temperature monitoring, and resumes normal operation.

Furthermore, in the above example, the control conditions can also be set such that although the operating temperature does not reach the cutoff control temperature, it continues to rise to a specific temperature at a specific time, that is, at the specific time, the output will also cut off the control temperature. Specific protection action information for the power supply of the electrical circuit 1. For example, although the cut-off control temperature 124.5°C of the first stage has not been reached, but the warning control temperature of 120°C has been reached, the temperature rise still reaches 2°C within 10 minutes, and the cut-off action is still performed. Also, in an extreme example, without considering the response time of the circuit, the nominal limit temperature TM _RM can also be regarded as the cut-off control temperature of each temperature rise control index, but the warning control temperature should still be based on different temperature rise indexes, and Different advance temperatures are given, so that enough time can be given to respond to different temperature rise control indicators. In the preferred case, the cut-off control temperature is preferably set below the nominal limit temperature TM _RM that will actually damage.

In addition, although the above-mentioned margin R takes time as an example, it can also be temperature, and according to the above method, the upper limit time of each step is deduced to determine the control point of each step, which is based on the control time. For example, if the margin R is 5 degrees, for example, the control time of the first stage is 1500 seconds, and the control time of the second stage is 600 seconds.

Further, the above-mentioned margin R is set as 50 seconds, but it can also be set by the user through the parameter setting unit 110 , or automatically generated by the overload protection device 100 or automatically generated according to the aforementioned protection sensitivity level. For example, in an example of setting a protection sensitivity level, if the protection sensitivity level is divided into 6 levels (extremely low/low/low-medium/medium/medium-high/high), and the margin R is 2/10/ 20/30/40/50 seconds, it can be set when the temperature difference between the nominal limit temperature TM _RM and the protection starting temperature TM _S is within 4.5°C, between 4.5°C and 9.5°C, and 9.5°C～14.5°C, respectively. between 14.5°C and 19.5°C, between 19.5°C and 24.5°C, and above 24.5°C, that is, the margin R is automatically set to 2 seconds, 10 seconds, 20 seconds, 30 seconds, 40 seconds, 50 seconds, respectively. seconds and corresponds to a sensitivity level of (very low, low, low medium, medium, medium high, high). In this way, a result of automatically setting the margin R can be achieved. In addition, the above is to automatically set the margin R based on the temperature difference, but it is also possible to set the margin R only based on the sensitivity level instead of the temperature difference; or set the margin R based on both the temperature difference and the sensitivity level, For example, the temperature difference is 20 degrees, the sensitivity level is high, and the margin R is, for example, 45 seconds.

The generation, setting and comparison of various control conditions have been described above, and then the reception and calculation of the operating temperature will be further described. When the overload protection device 100, which is an MCU or IC, senses that the operating temperature exceeds the protection starting temperature TM _S , it starts to collect the operating temperature information, including the temperature and time difference, for example, every 0.1 seconds or other intervals, start and end the collection. The temperature data of one point (sampling one point is enough), and calculate the temperature difference ΔTM. If the ΔTM is greater than 0.25°C, this is for example the measurement accuracy of the NTC temperature sensing component 150, that is, take the temperature of the nearest 2 points, and calculate it as the temperature. The angle θ of the rising index (tan ^-1 (△TM/0.01), in units of 10 seconds), or take the second point as the starting point, take the temperature of the nearest two points of the third point, and calculate the angle θ (tan ^-1 ( △TM/0.01)), and so on; if △TM<0.25℃, take the temperature of the nearest 1-3, 1-4, or 1-5 points to calculate the angle θ degrees (tan ^-1 (△TM/0.02 ), tan ^-1 (△TM/0.03), tan ^-1 (△TM/0.04)), or take the 3rd, 4th, and 5th points as the starting point, first take the temperature of the 4th, 5th, and 6th points at the nearest two points, If △TM is still less than 0.25°C, then take the temperature of the last two points at points 3-5, 4-6, and 5-7. And so on, calculate the angle θ (tan ^-1 [△TM/(0.01x2)], or tan ^-1 [△TM/(0.01x3)], tan ^-1 [△TM/(0.01x4)], etc.) ), and determine which step range it falls in. If it reaches the control temperature of the step, it will be turned off immediately, otherwise it will resume normal operation. In short, the working temperature rise index is when the temperature difference between two consecutive sampling points of the working temperature information is greater than a specific value, the working temperature rise index is calculated based on the working temperature information of the two sampling points; When the temperature difference is less than a specific value, the operating temperature rise index is calculated based on the operating temperature information obtained from at least two sampling points with a temperature difference greater than the specific value. As for the working temperature rise index, it can be an arc tangent angle or a slope.

Combining the above types, the control condition may be a combination of at least one of the control temperature, the control time, and the temperature rise control index of the working temperature under a time difference. Moreover, when the control condition is the cooperation of a certain temperature-rise control index and a certain control point, different control points can be given to different temperature-rise control indexes. Accordingly, the matrix control conditions can be obtained for different aspects, and the upper limit value is the nominal limit temperature TM _RM . When the received operating temperature information complies with any one of these control conditions, a protection message for executing a specific protection action is sent, and different specific protection actions can be given for different control conditions. The specific protection action may be to issue a warning, or to control the power supply status of the electrical circuit 1, or to perform the combination of both.

According to the above-mentioned various embodiments of the present invention, when a short circuit (Short) defined in the safety regulations occurs, the above-mentioned overload protection device can shut down the electric circuit 1 within 0.1 second or less at the fastest time. The accumulated thermal energy should not cause a component or device to catch fire, acting as a fuse. In addition, because the response speed of this overload protection device is greater than or equal to that of a fuse and is greater than that of a resettable circuit breaker, it does not matter even if there are no fuses and circuit breakers in the electrical circuit 1; The overload protection device can be cut off at the appropriate control temperature of each stage according to the actual circuit design and the designed safety control range, so it is also better than fuses and circuit breakers.

For example, if the load 13 is a heating pad, the internal resistance will increase when the heating wire is degraded, resulting in rapid loading and constant current flow, and the temperature will start to rise abnormally, which will also be reflected on the inlet component of the heating pad. Therefore, according to the above description, the weakest component is found in the power components of the electrical circuit 1, and the overload protection device disclosed in the present invention is added to the three-gate switch 14, which is the inlet component, and the inlet component that reflects this condition is added. The temperature rise index falls on the 7th level, which will be enough to turn off the power supply in real time (0.1 second), which can effectively ensure the safety of use.

Therefore, the overload protection device disclosed in the present invention can take into account the current overload protection caused by some internal or external equipment, it has the advantages of a fuse but no/less its disadvantages; it has the function of a circuit breaker but improves its shortcoming of slow response, so It can replace most of the fuses and circuit breakers, especially the devices that generate heat and frequently need to be turned on/off, such as heating pads, dehumidifiers, cooling fans, central air-conditioning outlet fans, etc.; device and can't predict what switch the device is connected to, such as sockets, adapter sockets, extension cords, wireless switches, etc. The overload protection device disclosed in the present invention has absolute advantages. In addition, if there are two inlet systems in the device, and one of the systems has the above situation, the device can also be used together with a fuse, or the system and the fuse can be used separately to protect each system separately.

According to the aforementioned various embodiments, the present invention also discloses a protection flow of the overload protection method as shown in FIG. 6 . As shown in FIG. 6 , the overload protection method according to an embodiment of the present invention includes:

The parameter setting step S1 is used to set a nominal limit temperature TM _RM of a benchmark power component located in an electrical circuit, and the benchmark power component has an operating temperature caused by passing one of the working currents;

The control condition generating step S2 is used to generate a plurality of control conditions representing the abnormal working temperature of the benchmark power component according to the nominal limit temperature TM _RM ;

The temperature collection step S3 is used to receive the operating temperature information of the benchmark power component; and,

In operation and output step S4 , according to the operating temperature information, an operating temperature rise index is calculated, and when the operating temperature rise index complies with one of the control conditions, a protection message for executing a specific protection action is sent. .

In a preferred embodiment, the temperature collection step further includes attaching a temperature sensing component to the benchmark power component to sense the working temperature and send the working temperature information; and the method further includes a regulating step S5 , is used to set the control device in the electric circuit, to receive the protection information, and to adjust the power supply of the electric circuit, and the adjustment includes cutting off. The benchmark power module, as mentioned above, can be the weakest module or the inlet module.

In another preferred embodiment, the protection method further includes: a warning step S6 for receiving the protection information and issuing a warning; and the specific protection action is to give different warning methods according to different control conditions; and the The control conditions include at least one of the control temperature, the control time, and the temperature rise control index of the working temperature within a period of time.

In addition, the aforementioned parameter setting step S1 may further include setting the protection starting temperature TM _S , the margin R, the protection extreme upper limit time difference _{T M} , the protection extreme lower time difference _{T S} , the control order, and the sensitivity level, at least among them One of them is used to complete the setting of various control conditions for each level, such as the upper limit temperature rise control index of each level, the upper limit angle of each level, the upper limit time difference of each level, and each control point as mentioned above. The effect achieved by the method disclosed in this embodiment is the same as that of the overload protection device.

To sum up the above, with the technical ideas disclosed by the various embodiments disclosed in the present invention, an overload protection device and method capable of obtaining the best overload protection can be obtained. At the same time, an optimal and intelligent overload protection device and method can be obtained, which can be adjusted by the user according to the actual circuit conditions to be protected, and can automatically generate various control points. Finally, it is emphasized that the constituent elements disclosed in the foregoing embodiments of the present invention are merely illustrative and not intended to limit the scope of the present application. Substitutions or changes of other equivalent elements should also be covered by the scope of the patent application of the present application.

Claims (20)

1. An overload protection apparatus, comprising:

a parameter setting unit for setting a nominal limit temperature of a benchmark power component in the power utilization circuit, wherein the benchmark power component has an operating temperature caused by passing one of the operating currents;

a control condition generating unit for generating a plurality of control conditions representing the abnormal working temperature of the benchmark power component according to the nominal limit temperature;

the temperature collecting unit is used for receiving the working temperature information of the benchmark power component; and the number of the first and second groups,

the operation output unit calculates the working temperature rise index according to the working temperature information and sends out protection information for executing specific protection actions when the working temperature rise index meets one of the control conditions.

2. The apparatus of claim 1, further comprising:

the temperature sensing component is attached to the benchmark power component and used for sensing the working temperature and sending out the working temperature information; and the number of the first and second groups,

the regulation and control device is arranged in the power utilization circuit and is used for receiving the protection signal and regulating the power supply of the power utilization circuit, and the regulation comprises the cut-off;

and the benchmark power component is one of all power components of the power circuit, and when the working current exceeds the rated load, the benchmark power component reaches the limit temperature at the highest speed, and the limit temperature is taken as the nominal limit temperature.

3. The apparatus of claim 1, further comprising:

the temperature sensing component is attached to the benchmark power component and used for sensing the working temperature and sending out the working temperature information; and the number of the first and second groups,

a control device, disposed in the power circuit, for receiving the protection signal and adjusting the power supply of the power circuit, wherein the adjustment includes cutting off;

and the benchmark power component is an inlet component of the power utilization loop, the weakest power component which reaches the limit temperature of the power utilization loop at the fastest speed when the working current exceeds the rated load is arranged in all the power components of the power utilization loop, and the nominal limit temperature is the working temperature of the benchmark power component when the weakest power component is at the limit temperature.

4. The apparatus of claim 1, further comprising: a warning device for receiving the protection signal and sending a warning; the specific protection action is given different warning modes according to different control conditions; and each of the control conditions includes at least one of a control temperature, a control time, and a temperature rise control indicator of the operating temperature under the time difference.

5. The apparatus of claim 1, wherein the control condition generating unit is configured to set an upper limit temperature rise control indicator of N-th order as the control conditions according to the nominal limit temperature, and a protection start temperature, an upper limit time difference, and a lower limit time difference, where N is a positive integer.

6. The apparatus of claim 5, wherein the regulation condition generating unit defines a 1 st upper limit angle of the N orders according to the upper limit difference and a temperature difference between the nominal limit temperature and the protection start temperature by taking an arctan thereof; and according to the minimum time difference and the temperature difference, the arctan angle is taken to define the upper limit angle of the N order; and using (the N-order upper limit angle-the 1 st order upper limit angle)/(N-1) as the range of each of the N-1 orders except the 1 st order, and sequentially accumulating the ranges of each of the N orders to obtain each of the N-1 orders upper limit angles; the N-level upper limit temperature rise control indicators refer to the upper limit angles of each level.

7. The apparatus of claim 6, wherein the regulation condition generating unit further comprises means for generating upper limit time differences of the N-1 orders according to the upper limit temperature rise regulation indicators of the N-1 orders and the nominal limit temperature, and the upper limit time differences of the N-1 orders are obtained according to the upper limit time differences and the ratio of the first upper limit tangent to the upper limit tangents of the orders.

8. The apparatus according to claim 5 or 7, wherein the control condition generating unit further comprises a step setting unit for setting an N-level control indicator as the control condition according to the margin R and each step upper limit temperature rise control indicator of the N-level upper limit temperature rise control indicator, and each step control indicator comprises a step upper limit temperature rise control indicator and a step control point calculated by the step upper limit temperature rise control indicator and the margin R; also, the margin amount R is a set amount advanced by a certain range as soon as one of the temperature and the time, and the regulation points include one of the regulated temperature and the regulated time.

9. The apparatus of claim 8, wherein the operation output unit compares the operating temperature rise index with the upper limit temperature rise control indexes of N orders to obtain a temperature rise conforming order, calculates a remaining time for the temperature rise to continue to rise to the control point of the temperature rise conforming order, and sends out different protection information according to the remaining time, and the specific protection action is to adjust at least one of power supply of the power circuit and alarm, the adjustment includes cutting off.

10. The apparatus of claim 5, wherein the parameter setting unit is further configured to set the protection start temperature, and the protection start temperature is a temperature of the benchmark power component when the power utilization loop is at its rated load.

11. The apparatus of claim 5, wherein the parameter setting unit is further configured to set a protection sensitivity level, and the protection start temperature is a temperature that is lower than the nominal limit temperature and varies according to the protection sensitivity level.

12. The apparatus of claim 8, wherein the margin is automatically set according to at least one of a temperature difference between the protection start temperature and the nominal limit temperature and a protection sensitivity level.

13. The apparatus of claim 1, wherein the operating temperature rise index is calculated from the operating temperature information of two consecutive sampling points of the operating temperature information when the temperature difference between the two sampling points is greater than or equal to a specific value; when the temperature difference between the two continuous sampling points is less than a specific value, the working temperature rise index is calculated by continuously sampling working temperature information obtained by two sampling points at intervals when the temperature difference is greater than the specific value.

14. An overload protection method, comprising:

a parameter setting step, which is used for setting the nominal limit temperature of a benchmark power component in the power utilization loop, wherein the benchmark power component has the working temperature caused by passing one of the working currents;

a control condition generating step for generating a plurality of control conditions representing the abnormal working temperature of the benchmark power component according to the nominal limit temperature;

a temperature collecting step for receiving the working temperature information of the benchmark power component; and the number of the first and second groups,

and a calculation output step, calculating the working temperature rise index according to the working temperature information, and sending out protection information for executing a specific protection action when the working temperature rise index meets one of the control conditions.

15. The method of claim 14, wherein the temperature collecting step further comprises attaching a temperature sensing element to the power device of the target for sensing the operating temperature and sending the operating temperature information; the method further comprises a control step for setting a control device in the power loop for receiving the protection information and adjusting the power supply of the power loop, wherein the adjustment comprises cutting off;

and the benchmark power component is one of all power components of the power circuit, and when the working current exceeds the rated load, the benchmark power component reaches the limit temperature at the highest speed, and the limit temperature is taken as the nominal limit temperature.

16. The method of claim 14, wherein the temperature collecting step further comprises attaching a temperature sensing element to the power device of the target for sensing the operating temperature and sending the operating temperature information; the method also comprises a regulation step for setting a regulation device in the power utilization loop to receive the protection information and regulate the power supply of the power utilization loop, wherein the regulation comprises cutting off;

and wherein the benchmark power component is an inlet component of the power utilization loop, among all power components of the power utilization loop, a weakest power component which reaches the limit temperature of the weakest power component at the highest speed when the working current exceeds the rated load is provided, and the nominal limit temperature is the working temperature of the benchmark power component when the weakest power component is at the limit temperature.

17. The method of claim 14, further comprising: an alarm step, for receiving the protection information and sending out an alarm; the specific protection action is given different warning modes according to different control conditions; the control condition includes at least one of a control temperature, a control time, and a temperature rise control indicator of the working temperature in a time zone.

18. The method of claim 14, wherein the controlling condition generating step is used for setting an upper temperature-rise controlling indicator of N-th order as the controlling conditions according to the nominal limit temperature, and the protection starting temperature, the upper limit time difference, and the lower limit time difference, where N is a positive integer; and is used for defining the 1 st order upper limit angle in the N orders according to the upper limit time difference and the temperature difference between the nominal limit temperature and the protection initial temperature; and according to the minimum time difference and the temperature difference, the arctan angle is taken to define the upper limit angle of the N order; and using (the N-order upper limit angle-the 1 st order upper limit angle)/(N-1) as the range of each of the N-1 orders except the 1 st order, and sequentially accumulating the ranges of each of the N orders to obtain each of the N-1 orders upper limit angles; the N-level upper limit temperature rise control indicators refer to the upper limit angles of each level.

19. The method of claim 18, wherein the step of generating the control condition further comprises setting an N-level control indicator as the control condition according to the margin and each of the N-level upper temperature rise control indicators, wherein each of the N-level control indicators comprises a level upper temperature rise control indicator and a level control point calculated by the level upper temperature rise control indicator and the margin; also, the margin amount is a set amount advanced by a certain range as soon as one of the temperature and the time, and the regulation points include one of the regulated temperature and the regulated time.

20. The method of claim 19, wherein the operation output step compares the operating temperature rise index with the upper limit temperature rise control indicators of N orders to obtain a temperature rise compliance level, calculates a remaining time for the operating temperature rise index to continue to rise to the control point of the temperature rise compliance level, and sends out different protection information according to the remaining time, and the specific protection action is at least one of adjusting power supply of the power circuit and giving out an alarm, the adjusting including cutting off.

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