CN112186721B - Electric fire-proof current-limiting protector - Google Patents

Electric fire-proof current-limiting protector Download PDF

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Publication number
CN112186721B
CN112186721B CN202011059575.2A CN202011059575A CN112186721B CN 112186721 B CN112186721 B CN 112186721B CN 202011059575 A CN202011059575 A CN 202011059575A CN 112186721 B CN112186721 B CN 112186721B
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current
load
level
waveform
wave
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CN112186721A (en
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何晓东
张基恩
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Jiangsu Weichuang Things Technology Co ltd
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Jiangsu Weichuang Things Technology Co ltd
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    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02HEMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H9/00Emergency protective circuit arrangements for limiting excess current or voltage without disconnection
    • H02H9/02Emergency protective circuit arrangements for limiting excess current or voltage without disconnection responsive to excess current
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02HEMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H1/00Details of emergency protective circuit arrangements
    • H02H1/0007Details of emergency protective circuit arrangements concerning the detecting means
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02HEMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H9/00Emergency protective circuit arrangements for limiting excess current or voltage without disconnection
    • H02H9/02Emergency protective circuit arrangements for limiting excess current or voltage without disconnection responsive to excess current
    • H02H9/025Current limitation using field effect transistors

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Emergency Protection Circuit Devices (AREA)

Abstract

The invention relates to an electric fire-proof current-limiting protector, which comprises a main circuit, a plurality of load branches, an alternating current power supply, a sliding rheostat and a central control unit, wherein the alternating current power supply is connected with the main circuit in series, the main circuit is respectively connected with the load branches, the load branches are connected in parallel, the alternating current power supply supplies power for the load branches, the sliding rheostat is connected with the alternating current power supply in parallel and is used for changing the output voltage of the alternating current power supply, when a short-circuit fault occurs, the electric fire-proof current-limiting protector can realize rapid current-limiting protection at microsecond speed, and the sliding resistor is adjusted to realize voltage adjustment and further adjust current, so that the working current is limited within a range which is several times of rated working current, thereby effectively preventing and reducing the hidden danger of electric fire, the safety of the load is ensured.

Description

Electric fire-proof current-limiting protector
Technical Field
The invention relates to the field of circuit protection, in particular to an electric fireproof current-limiting protector.
Background
With the increasing demand of electric power, electrical equipment is increasing continuously, and in the process of power utilization, in order to prevent human body electric shock and fire accidents caused by defects of the electrical equipment or improper use, a current-limiting protector is required to be installed in a circuit, so that the situations of heating and even electrical fire and the like caused by overcurrent phenomena in the circuit are effectively prevented.
The current limiter is a device for limiting the current in a circuit, can limit fault short-circuit current, and improves the stability of a power grid. The ideal current limiter has no influence on the normal operation of the power grid, and can limit the short-circuit current to be close to the rated current value in the case of fault. A commonly used current limiter is a superconducting current limiter, which utilizes the physical property of the superconductor that the superconducting state is transformed from the normal state, and when the line normally runs, the superconductor presents zero impedance or extremely small impedance, and does not cause any adverse effect on power transmission. When the line is in fault, the current passing through the superconductor exceeds a certain value, the superconductor is instantly changed into a normal state, a proper impedance is generated to realize current limiting, and when the fault line is disconnected or the fault disappears, the current limiter is automatically reset.
However, the current limiter in the related art has a single function, and cannot perform special treatment for specific power utilization situations, which affects normal use of power.
Disclosure of Invention
Therefore, the invention provides an electric fireproof current-limiting protector which can be safely started in a starting-up process, and ensures the circuit safety of the electric fireproof current-limiting protector in a load overcurrent state.
In order to achieve the above object, the present invention provides an electric fire-proof current-limiting protector, comprising: the alternating current power supply is connected with the main circuit in series, the main circuit is connected with the load branches respectively, the load branches are connected in parallel, the alternating current power supply supplies power to the load branches, main current detection equipment is arranged on the main circuit and used for detecting current on the main circuit in real time, load current detection equipment and a switch module are arranged on each load branch and used for detecting current flowing through a load in real time, the switch module is used for connecting or disconnecting the load branches, and the slide rheostat is connected with the alternating current power supply in parallel and used for changing output voltage of the alternating current power supply; the central control unit is respectively connected with the main current detection device, the load current detection device, the sliding rheostat and the switch module and is used for controlling the on-off of the switch module or changing the actual resistance of the sliding resistor according to the detection results of the main current detection device and the load current detection device; a load current value matrix I (I1, I2, I3) is arranged in the central control unit, wherein I1< I2< I3, I1 represents a first-level current of a current flowing through a load, I2 represents a second-level current of the current flowing through the load, I3 represents a third-level current of the current flowing through the load, the current on the main circuit is I0, and for a real-time current ii of an I-th load branch, the sum of the real-time currents of the load branches is less than or equal to the current I0 on the main circuit; for the first load current I1, when I1< I1, detecting a second load current and a third load current, and if the second load current I2 and the third load current I3 are both smaller than the first-level current I1, the circuit is safe and has no overcurrent risk; if the second load current I1 is less than I2 and less than I2, detecting a third load current, if the third load current is less than a third level current I3, the circuit is safe, otherwise, an overcurrent risk exists, and disconnecting a switch module of the third load; for the first load current I1, when I1< I1< I2, detecting a second load current and a third load current, and if the second load current I2 and the third load current I3 are both smaller than the first-level current I1, the circuit is safe and has no overcurrent risk; if the second load current I2 and the third load current I3 are both greater than the first level current I1 and less than the second level current I2, changing the resistance of the sliding rheostat to reduce the output voltage of the power supply, if the second load current I2 is greater than the first level current I1 and less than the second level current I2, detecting the third load current I3, and if the third load current I3 is greater than the third level current, disconnecting the switch module of the third load by the central control unit; for the first load current I1, when I2< I1< I3, detecting a second load current and a third load current, and if the second load current I2 and the third load current I3 are both smaller than the first-level current I1, the circuit is safe and has no overcurrent risk; if the second load current I2 is greater than the first level current I1 and less than the second level current I2, the resistance of the sliding rheostat is changed to reduce the output voltage of the power supply, if the second load current I2 is greater than the second level current I2 and less than the third level current I3, the resistance of the sliding rheostat is changed to reduce the output voltage of the power supply, and if the second load current I2 is greater than the third level current I3, the central control unit disconnects the switch module of the third load; for a first load current I1, when I3< I1, the central control unit opens the switch module of the first load.
Further, a safety voltage U0 is arranged in the central control unit, for the first load, the third load and the third load, when the real-time current of two of the three loads is greater than the second-level current, the output voltage of the power supply is adjusted to 0.8 × U0, when the real-time current of two of the three loads is greater than the first-level current and less than the second-level current, the output voltage of the power supply is adjusted to 0.9 × U0, and if the circuit is safe, the output voltage of the power supply is a safety voltage U0.
Further, for the ith load branch, detecting real-time current of the load branch within a preset time period T to obtain a current waveform diagram ii (T) within the period, wherein a current waveform matrix (λ 1, λ 2, λ 3, … …, λ n) is arranged in the central control unit, λ 1 represents a first current waveform diagram, λ 2 represents a second current waveform diagram, λ 3 represents a third current waveform diagram, … …, λ n represents an nth current waveform diagram, and if the obtained current waveform diagram ii (T) is within the range of the wavelength matrix within the preset time period, the detected real-time current value is correct;
if the detected current waveform pattern ii (t) has a current value at N times that is not on any waveform pattern, the current waveform matrix pattern including the most points is selected as the actual current waveform pattern.
Further, sorting is carried out according to the magnitude of the load current, the load current is used from small to large, when the load with the minimum current is used for a preset time, a load circuit needs to be replaced, the next load to be used is judged, and the selection of the load to be used is determined according to the sorting of the magnitude of the current of all the loads except the current load;
the safe voltage U0 is the current i0 x the real-time resistance of the sliding resistor on the main circuit.
Further, a standard current difference value is arranged in the central control unit, in a preset time period, the current waveform diagram ii (t) is compared with any current waveform diagram in the wavelength matrix to obtain a waveform difference value, and at any moment, if the waveform difference value is smaller than the standard current difference value, the current waveform diagram is an actual current waveform diagram;
if the waveform difference is greater than the standard current difference and the current waveform pattern ii (t) is close to any two waveform patterns in the current waveform matrix, the current waveform pattern ii (t) is the average value of any two waveform patterns after being superimposed.
Further, for the ith load branch, if within a preset time period T, the current waveform diagram ii (T) within the period includes m peaks and n troughs, a peak matrix P (P1, P2, … Pm) and a trough matrix T (T1, T1, … Tn) are respectively determined, a peak mean value and a trough mean value are further set in the central control unit, if there are more than m/2 actual peak values higher than the peak mean value within the preset period, a trough matrix is detected, and if there are more than n/2 actual trough values lower than the trough mean value, the resistance value of the sliding rheostat is adjusted, and the real-time voltage on the main circuit is reduced;
if the current waveform diagram ii (T) in the period comprises m wave crests and n wave troughs in a preset time period T, respectively determining a wave crest matrix P (P1, P2, … Pm) and a wave trough matrix T (T1, T1, … Tn), and also setting a wave crest mean value and a wave trough mean value in the central control unit, if less than m/3 actual wave crest values are higher than the wave crest mean value in the preset period, detecting a wave trough matrix, and if more than n/3 actual wave trough values are lower than the wave trough mean value, maintaining the real-time voltage on the main circuit;
if the current waveform diagram ii (T) in the period comprises m wave crests and n wave troughs in the preset time period T, respectively determining a wave crest matrix P (P1, P2, … Pm) and a wave trough matrix T (T1, T1, … Tn), and also setting a wave crest mean value and a wave trough mean value in the central control unit, if more than 3m/4 actual wave crest values are lower than the wave crest mean value in the preset period, detecting a wave trough matrix, and if more than 3n/4 actual wave trough values are higher than the wave trough mean value, improving the real-time voltage on the main circuit.
Furthermore, a superposed waveform is also arranged in the central control unit, and when the actual current waveform needs to be adjusted, the actual current waveform and the superposed waveform are superposed to be used as the correction of the real-time current.
Further, the switch module is an MOS tube.
Further, the resistance value of the slide rheostat of the alternating current power supply ranges from 0 k ohm to 5k ohm.
Further, the central control unit is a central processing unit.
Further, the main current detection device and the load current detection device are both automatic detection devices.
Compared with the prior art, the electric fire-proof current-limiting protector has the beneficial effects that when short-circuit faults occur, the electric fire-proof current-limiting protector can realize rapid current-limiting protection at microsecond-level speed, and the voltage and the current are regulated by regulating the sliding resistor, so that the working current is limited within a range of multiple times of the rated working current, thereby effectively eliminating electric sparks caused by the short-circuit current and preventing and reducing the hidden danger of electric fire; when overload current faults occur, the switch is immediately disconnected, and the safety of the load is guaranteed.
Particularly, if the central control unit pre-determines that the overcurrent risk exists according to the magnitude of the real-time load current, the central control unit can be used for controlling the slide rheostat so as to reduce the current or directly disconnect the corresponding switch module in a mode of reducing the output voltage of the power supply, so that the overcurrent risk is blocked in time, and the real-time safety of the circuit is effectively protected.
According to the magnitude of the real-time current of the load and the preset current level, different safety measures are selected, the circuit is managed more efficiently and intelligently, and the utilization rate and the effective output of the circuit are further improved on the premise that the safety performance of the circuit is guaranteed.
When the voltage of the electric fireproof current limiting protector is adjusted, the safety voltage is adopted for supplying power when the load current is normal, and when the current is overlarge, the voltage is regulated in a grading way according to the excess magnitude of the current, so that the normal operation of a circuit is ensured, the safety of the circuit is ensured, the safety requirement of the circuit can be met, and the normal work of the circuit can be considered.
Particularly, when the actual current is too large, if the current is only due to other interference, no substantial damage is caused at the moment when the current becomes large, if the current is too strict, the power-off processing is required, the use condition of the load is certainly influenced, in order to consider the working condition of the load and the safety of the circuit, the electric fireproof current type protector provided by the embodiment of the invention is provided with the waveform matrix, a certain allowable error is set, if the allowable error is within an error range, the overcurrent phenomenon is allowed to be processed, and the accuracy and the rapidness of the current regulation are ensured.
Particularly, for the real-time current on any branch, the current in the period is detected and judged, so as to judge whether the circuit has overcurrent risk, and the real-time voltage on the main circuit is adjusted according to the magnitude of the overcurrent risk degree, specifically, a peak mean value and a trough matrix are arranged in the central control unit, the electric fire protection device provided by the embodiment of the invention compares the peak mean value with m actual wave peak values in the period, judges the trough mean value again according to the comparison result to compare with n actual wave troughs in the period, and selects to increase the voltage of the main circuit according to the comprehensive comparison result of the peak and the trough, reduces the voltage of the main circuit or keeps the voltage of the main circuit, so that when the overcurrent risk exists in the preset period, the judgment is carried out according to the actual overcurrent number of the peak and the trough, and the real-time adjustment of the voltage is carried, the risk of overcurrent in the preset period is greatly reduced, and the safety of the circuit is improved.
Particularly, in the actual use process, the real-time currents of the loads are sorted, specifically, the loads can be sorted according to the actual sizes of the currents, when the loads are used, the branch with the minimum load current is preferentially used, the risk of overcurrent in the use process is greatly reduced by selecting the branch with the smaller load current, in addition, when the load branch is used for a preset time, the preset time of the load branch is reached, the loads need to be replaced, when the loads are selected, because the voltage possibly changes in real time, other load branches need to be re-sorted after the preset time, the load branch with the minimum current is determined, the load branch is selected as the next branch to be used, the current value of the replaced load branch is guaranteed to be minimum, the risk of overcurrent is effectively prevented, and the use safety of the circuit is further improved. .
Drawings
Fig. 1 is a schematic circuit structure diagram of an electrical fire-proof current-limiting protector provided in an embodiment of the present invention.
Detailed Description
In order that the objects and advantages of the invention will be more clearly understood, the invention is further described below with reference to examples; it should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
Preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only for explaining the technical principle of the present invention, and do not limit the scope of the present invention.
It should be noted that in the description of the present invention, the terms of direction or positional relationship indicated by the terms "upper", "lower", "left", "right", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, which are only for convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.
Furthermore, it should be noted that, in the description of the present invention, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
Referring to fig. 1, the present invention provides an electric fire-proof current-limiting protector, comprising: the alternating current power supply is connected with the main circuit in series, the main circuit is connected with the load branches respectively, the load branches are connected in parallel, the alternating current power supply supplies power to the load branches, main current detection equipment is arranged on the main circuit and used for detecting current on the main circuit in real time, load current detection equipment and a switch module are arranged on each load branch and used for detecting current flowing through a load in real time, the switch module is used for connecting or disconnecting the load branches, and the slide rheostat is connected with the alternating current power supply in parallel and used for changing output voltage of the alternating current power supply; the central control unit is respectively connected with the main current detection device, the load current detection device, the sliding rheostat and the switch module and is used for controlling the on-off of the switch module or changing the actual resistance of the sliding resistor according to the detection results of the main current detection device and the load current detection device; a load current value matrix I (I1, I2, I3) is arranged in the central control unit, wherein I1< I2< I3, I1 represents a first-level current of a current flowing through a load, I2 represents a second-level current of the current flowing through the load, I3 represents a third-level current of the current flowing through the load, the current on the main circuit is I0, and for a real-time current ii of an I-th load branch, the sum of the real-time currents of the load branches is less than or equal to the current I0 on the main circuit; for the first load current I1, when I1< I1, detecting a second load current and a third load current, and if the second load current I2 and the third load current I3 are both smaller than the first-level current I1, the circuit is safe and has no overcurrent risk; if the second load current I1 is less than I2 and less than I2, detecting a third load current, if the third load current is less than a third level current I3, the circuit is safe, otherwise, an overcurrent risk exists, and disconnecting a switch module of the third load; for the first load current I1, when I1< I1< I2, detecting a second load current and a third load current, and if the second load current I2 and the third load current I3 are both smaller than the first-level current I1, the circuit is safe and has no overcurrent risk; if the second load current I2 and the third load current I3 are both greater than the first level current I1 and less than the second level current I2, changing the resistance of the sliding rheostat to reduce the output voltage of the power supply, if the second load current I2 is greater than the first level current I1 and less than the second level current I2, detecting the third load current I3, and if the third load current I3 is greater than the third level current, disconnecting the switch module of the third load by the central control unit; for the first load current I1, when I2< I1< I3, detecting a second load current and a third load current, and if the second load current I2 and the third load current I3 are both smaller than the first-level current I1, the circuit is safe and has no overcurrent risk; if the second load current I2 is greater than the first level current I1 and less than the second level current I2, the resistance of the sliding rheostat is changed to reduce the output voltage of the power supply, if the second load current I2 is greater than the second level current I2 and less than the third level current I3, the resistance of the sliding rheostat is changed to reduce the output voltage of the power supply, and if the second load current I2 is greater than the third level current I3, the central control unit disconnects the switch module of the third load; for a first load current I1, when I3< I1, the central control unit opens the switch module of the first load.
Specifically, the electric fire-proof current-limiting protector provided by the embodiment of the invention can effectively limit the current of the circuit to be overlarge, prevent electric sparks caused by the overlarge current, ensure that the circuit is safer in use and prolong the service life.
Specifically, the embodiment of the invention realizes the respective management of the load currents by monitoring the load currents in real time and setting the level currents for the load currents in advance, and for the first load current I1, when I1 is less than I1, the second load current and the third load current are detected, and if the second load current I2 and the third load current I3 are both less than the first level current I1, the circuit is safe without overcurrent risk, and the circuit is safe and can supply power to each load; if the second load current I1 is less than I2 and less than I2, detecting a third load current, if the third load current is less than a third level current I3, the circuit is safe, otherwise, an overcurrent risk exists, and disconnecting a switch module of the third load; for the first load current I1, when I1< I1< I2, detecting a second load current and a third load current, and if the second load current I2 and the third load current I3 are both smaller than the first-level current I1, the circuit is safe and has no overcurrent risk; if the second load current I2 and the third load current I3 are both greater than the first level current I1 and less than the second level current I2, changing the resistance of the sliding rheostat to reduce the output voltage of the power supply, if the second load current I2 is greater than the first level current I1 and less than the second level current I2, detecting the third load current I3, and if the third load current I3 is greater than the third level current, disconnecting the switch module of the third load by the central control unit; for the first load current I1, when I2< I1< I3, detecting a second load current and a third load current, and if the second load current I2 and the third load current I3 are both smaller than the first-level current I1, the circuit is safe and has no overcurrent risk; if the second load current I2 is greater than the first level current I1 and less than the second level current I2, the resistance of the sliding rheostat is changed to reduce the output voltage of the power supply, if the second load current I2 is greater than the second level current I2 and less than the third level current I3, the resistance of the sliding rheostat is changed to reduce the output voltage of the power supply, and if the second load current I2 is greater than the third level current I3, the central control unit disconnects the switch module of the third load; for a first load current I1, when I3< I1, the central control unit opens the switch module of the first load. By pre-judging the risk possibly existing in the load and timely processing the risk, the overcurrent danger can be effectively avoided, and the utilization rate and the safety of the circuit are improved.
When the central control unit judges that the overcurrent risk exists in advance according to the magnitude of the real-time load current, the central control unit can be used for controlling the slide rheostat so as to reduce the current or directly disconnect the corresponding switch module in a mode of reducing the output voltage of the power supply, the overcurrent risk is blocked in time, and the real-time safety of the circuit is effectively protected.
According to the magnitude of the real-time current of the load and the preset current level, different safety measures are selected, the circuit is managed more efficiently and intelligently, and the utilization rate and the effective output of the circuit are further improved on the premise that the safety performance of the circuit is guaranteed.
Compared with the prior art, the invention has the following beneficial effects: when short-circuit fault occurs, the electric fire-proof current-limiting protector can realize rapid current-limiting protection at microsecond speed, and adjust voltage and current by adjusting the sliding resistor, so that the working current is limited within the range of rated working current, thereby effectively eliminating electric spark caused by short-circuit current and preventing and reducing hidden danger of electric fire; when overload current faults occur, the switch is immediately disconnected, and the safety of the load is guaranteed. Because the electric fire-proof current-limiting protector adopts a high-speed current detection technology, when instantaneous current sharply increases due to short circuit of an electric line, the current-limiting protection can be quickly detected and implemented, and the control sensitivity of the current-limiting protector is improved by thousands of times compared with that of a common circuit breaker.
In addition, the electric fireproof current-limiting protector provided by the embodiment of the invention can realize quick breaking current-limiting protection when short-circuit fault occurs, so that fire disaster early warning can be timely carried out when the short-circuit fault occurs.
In addition, the high-performance MOSFET tubes are connected in series and parallel to form the main control switch unit, so that the structure is simple, and the current is easy to expand. Meanwhile, the main control switch unit composed of high-performance MOSFET tubes is used as a solid-state electronic switch, so that the defects of the traditional fuse and circuit breaker are fundamentally overcome, and the solid-state electronic switch has the advantages of no spark, high switching speed, long service life and low power consumption.
Further, a safety voltage U0 is arranged in the central control unit, for the first load, the third load and the third load, when the real-time current of two of the three loads is greater than the second-level current, the output voltage of the power supply is adjusted to 0.8 × U0, when the real-time current of two of the three loads is greater than the first-level current and less than the second-level current, the output voltage of the power supply is adjusted to 0.9 × U0, and if the circuit is safe, the output voltage of the power supply is a safety voltage U0.
In the current structure with three loads, if more than half of the current of the load is greater than the current of the second level, it is indicated that the overcurrent risk is large, during the adjustment, in order to further reduce the risk, the output voltage of the power supply is adjusted to 0.8 × U0, and if more than half of the current of the load is between the current of the first level and the current of the second level, it is indicated that the intermediate level of the overcurrent risk exists, at this time, the output voltage of the power supply can be set to 0.9 × U0, if no overcurrent risk exists, the safety voltage U0 is adopted, it can be understood by those skilled in the art that different magnitudes of the power supply voltage correspond to different overcurrent risk degrees, if the overcurrent risk is large, the magnitude of the output voltage of the power supply can be reduced by a little, the safety of the load current can be ensured, if the overcurrent risk is moderate, the magnitude of the output voltage of the power supply can be reduced by a little, the normal output of the circuit is ensured, the overcurrent risk is reduced, and the circuit is effectively protected.
Specifically, when the voltage of the electrical fire-proof current limiting protector provided by the embodiment of the invention is adjusted, the safety voltage is adopted for supplying power when the load current is normal, and when the current is too large, the voltage is regulated in a grading manner according to the excessive magnitude of the current, so that the normal operation of the circuit is ensured, the safety requirement of the circuit can be met, and the normal operation of the circuit can be considered.
Specifically, for an ith load branch, detecting real-time current of the load branch within a preset time period T to obtain a current waveform diagram ii (T) within the period, wherein a current waveform matrix (λ 1, λ 2, λ 3, … …, λ n) is arranged in the central control unit, λ 1 represents a first current waveform diagram, λ 2 represents a second current waveform diagram, λ 3 represents a third current waveform diagram, … …, λ n represents an nth current waveform diagram, and if the obtained current waveform diagram ii (T) is within the range of the wavelength matrix within the preset time period, the detected real-time current value is correct; if the detected current waveform pattern ii (t) has a current value at N times that is not on any waveform pattern, the current waveform matrix pattern including the most points is selected as the actual current waveform pattern.
Specifically, when the actual current is too large, if the current is only due to other interference, no substantial damage is caused at the moment when the current becomes large, if the current is too strict, the power-off processing is required, the use condition of the load is certainly influenced, and in order to consider the working condition of the load and the safety of the circuit, the electric fireproof current type protector provided by the embodiment of the invention is provided with the waveform matrix, a certain allowable error is set, if the allowable error is within an error range, the overcurrent phenomenon is allowed to be processed, and the accuracy and the rapidness of current regulation are ensured.
Specifically, the loads are sorted according to the magnitude of the load current, the loads are used from small to large according to the load current, when the load with the minimum current is used for a preset time, the load circuit needs to be replaced, the next load to be used is judged, the loads to be used are selected according to the sorting of the magnitude of the current of all the loads except the current load, and the safe voltage U0 is the real-time resistance value of the current i0 multiplied by the sliding resistor on the main circuit.
In the actual use process, the real-time currents of the loads are sorted, and the sorting can be specifically carried out according to the actual magnitude of the currents, when in use, the branch with the minimum load current is preferentially used, and the branch with the smaller load current is selected, so that the risk of overcurrent during use is greatly reduced, in addition, when the load branch circuit is used for the preset time, the load branch circuit needs to be replaced when the preset time of the load branch circuit is reached, when the load branch circuit is selected, because the voltage may change in real time, other load branch circuits need to be reordered after the preset time, the load branch circuit with the minimum current is determined, and the load branch circuit is selected as the next branch circuit to be used, so that the current value of the replaced load branch circuit is still minimum, the risk of overcurrent is effectively prevented, and the use safety of the circuit is further improved.
Specifically, a standard current difference value is set in the central control unit, in a preset time period, the current waveform diagram ii (t) is compared with any current waveform diagram in the wavelength matrix to obtain a waveform difference value, and at any time, if the waveform difference value is smaller than the standard current difference value, the current waveform diagram is an actual current waveform diagram; if the waveform difference is greater than the standard current difference and the current waveform pattern ii (t) is close to any two waveform patterns in the current waveform matrix, the current waveform pattern ii (t) is the average value of any two waveform patterns after being superimposed.
Specifically, a superimposed waveform is further arranged in the central control unit, and when the actual current waveform needs to be adjusted, the actual current waveform and the superimposed waveform are superimposed to be used as the correction of the real-time current.
The real-time current is corrected by adopting the superposed waveform, and the superposed waveform is directly superposed, so that the method is convenient and rapid, the rapid response to the current value is realized, and the rapidity and the safety of circuit control are ensured.
Specifically, for the ith load branch, if within a preset time period T, a current waveform diagram ii (T) within the period includes m peaks and n troughs, a peak matrix P (P1, P2, … Pm) and a trough matrix T (T1, T1, … Tn) are respectively determined, a peak mean value and a trough mean value are further set in the central control unit, if there are more than m/2 actual peak values higher than the peak mean value within the preset period, a trough matrix is detected, and if there are more than n/2 actual trough values lower than the trough mean value, the resistance value of the sliding rheostat is adjusted, and the real-time voltage on the main circuit is reduced;
if the current waveform diagram ii (T) in the period comprises m wave crests and n wave troughs in a preset time period T, respectively determining a wave crest matrix P (P1, P2, … Pm) and a wave trough matrix T (T1, T1, … Tn), and also setting a wave crest mean value and a wave trough mean value in the central control unit, if less than m/3 actual wave crest values are higher than the wave crest mean value in the preset period, detecting a wave trough matrix, and if more than n/3 actual wave trough values are lower than the wave trough mean value, maintaining the real-time voltage on the main circuit;
if the current waveform diagram ii (T) in the period comprises m wave crests and n wave troughs in the preset time period T, respectively determining a wave crest matrix P (P1, P2, … Pm) and a wave trough matrix T (T1, T1, … Tn), and also setting a wave crest mean value and a wave trough mean value in the central control unit, if more than 3m/4 actual wave crest values are lower than the wave crest mean value in the preset period, detecting a wave trough matrix, and if more than 3n/4 actual wave trough values are higher than the wave trough mean value, improving the real-time voltage on the main circuit.
In practical application, for real-time current on any branch, the current in a period is detected and judged, whether the circuit has overcurrent risk is judged, and real-time voltage on the main circuit is regulated according to the magnitude of the overcurrent risk degree, specifically, a peak mean value and a trough matrix are arranged in a central control unit, the electric fire protection device provided by the embodiment of the invention compares the peak mean value with m actual peak values in the period, judges the trough mean value again according to the comparison result to compare with n actual troughs in the period, selects to increase the voltage of the main circuit according to the comprehensive comparison result of the peak and the trough, reduces the voltage of the main circuit or keeps the voltage of the main circuit, so that when overcurrent risk exists in a preset period, judgment is carried out according to the actual overcurrent number of the peak and the trough, and real-time regulation of the voltage is carried out according to the judgment result, the risk of overcurrent in the preset period is greatly reduced, and the safety of the circuit is improved.
Specifically, the switch module is a MOS tube. The high-performance MOSFET tubes are connected in series and parallel to form the main control switch unit, so that the main control switch unit is simple in structure and easy to expand current. Meanwhile, the main control switch unit composed of high-performance MOSFET tubes is used as a solid-state electronic switch, so that the defects of the traditional fuse and circuit breaker are fundamentally overcome, and the solid-state electronic switch has the advantages of no spark, high switching speed, long service life and low power consumption.
Specifically, the number of load branches is three.
In practical application, the number of load branches can be multiple, and is not limited, the embodiment of the invention adopts three load branches for illustration, so that the power utilization condition of the load branches can be effectively supplied, the real-time change of a circuit can be conveniently observed, the adjustment is convenient, the convenience and the rapidness are realized, the adjustment time is saved, the quick response to the condition of the circuit is convenient, and the statistics of an experiment and the tracking of an experiment result are convenient.
Specifically, the resistance value of the alternating current power supply is in a range of 0-5k ohms.
The resistance range of the slide rheostat determines the adjustment precision range of the voltage value, so that the voltage is adjusted more accurately, and the accuracy and convenience of voltage control adjustment are realized.
Specifically, the central control unit is a central processing unit. Adopt central processing unit, the processing speed is fast, needs to carry out voltage and the unified processing of the adjustment of switch to overflowing in the circuit, and integrated management, information is concentrated, and overall planning, convenient and fast. The intelligent fire-proof monitoring system has the advantages that the embedded intelligent system combining hardware and software is realized by adopting the high-performance microprocessor, the reliability and the flexibility of the system are improved, the online communication interface and the monitoring software realize real-time intelligent centralized monitoring on the running data of the electric circuit, and the intelligent management of the fire-proof monitoring system is convenient to realize.
The electric fire-proof current-limiting protector can be applied to various places where electric fire easily occurs, such as schools, hospitals, ancient buildings, temples, hotels, entertainment places, commodity market and exhibition centers, warehouses and factories, and can also be applied to the fields of petroleum, chemical engineering, automobiles, ships, aviation and the like.
Specifically, the main current detection device and the load current detection device are both automatic detection devices. Adopt automatic formula check out test set, need not artifical the participation, the electric current that directly will gather transmits to well accuse unit, realizes real-time incessant control to data carry out further processing, high-efficient, convenient.
So far, the technical solutions of the present invention have been described in connection with the preferred embodiments shown in the drawings, but it is easily understood by those skilled in the art that the scope of the present invention is obviously not limited to these specific embodiments. Equivalent changes or substitutions of related technical features can be made by those skilled in the art without departing from the principle of the invention, and the technical scheme after the changes or substitutions can fall into the protection scope of the invention.
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention; various modifications and alterations to this invention will become apparent to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. An electrical fire protection current limiting protector, comprising: the alternating current power supply is connected with the main circuit in series, the main circuit is connected with the load branches respectively, the load branches are connected in parallel, the alternating current power supply supplies power to the load branches, main current detection equipment is arranged on the main circuit and used for detecting current on the main circuit in real time, load current detection equipment and a switch module are arranged on each load branch and used for detecting current flowing through a load in real time, the switch module is used for connecting or disconnecting the load branches, and the slide rheostat is connected with the alternating current power supply in parallel and used for changing output voltage of the alternating current power supply;
the central control unit is respectively connected with the main current detection device, the load current detection device, the sliding rheostat and the switch module and is used for controlling the on-off of the switch module or changing the actual resistance of the sliding rheostat according to the detection results of the main current detection device and the load current detection device;
a load current value matrix I (I1, I2, I3) is arranged in the central control unit, wherein I1< I2< I3, I1 represents a first-level current of a current flowing through a load, I2 represents a second-level current of the current flowing through the load, I3 represents a third-level current of the current flowing through the load, the current on the main circuit is I0, and for a real-time current ii of an I-th load branch, the sum of the real-time currents of the load branches is less than or equal to the current I0 on the main circuit;
for the first load current I1, when I1< I1, detecting a second load current and a third load current, and if the second load current I2 and the third load current I3 are both smaller than the first-level current I1, the circuit is safe and has no overcurrent risk; if the second load current I1 is less than I2 and less than I2, detecting a third load current, if the third load current is less than a third level current I3, the circuit is safe, otherwise, an overcurrent risk exists, and disconnecting a switch module of the third load;
for the first load current I1, when I1< I1< I2, detecting a second load current and a third load current, and if the second load current I2 and the third load current I3 are both smaller than the first-level current I1, the circuit is safe and has no overcurrent risk; if the second load current I2 and the third load current I3 are both greater than the first level current I1 and less than the second level current I2, changing the resistance of the sliding rheostat to reduce the output voltage of the power supply, if the second load current I2 is greater than the first level current I1 and less than the second level current I2, detecting the third load current I3, and if the third load current I3 is greater than the third level current, disconnecting the switch module of the third load by the central control unit;
for the first load current I1, when I2< I1< I3, detecting a second load current and a third load current, and if the second load current I2 and the third load current I3 are both smaller than the first-level current I1, the circuit is safe and has no overcurrent risk; if the second load current I2 is greater than the first level current I1 and less than the second level current I2, the resistance of the sliding rheostat is changed to reduce the output voltage of the power supply, if the second load current I2 is greater than the second level current I2 and less than the third level current I3, the resistance of the sliding rheostat is changed to reduce the output voltage of the power supply, and if the second load current I2 is greater than the third level current I3, the central control unit disconnects the switch module of the second load;
for a first load current I1, when I3< I1, the central control unit opens the switch module of the first load.
2. The electrical fire-protection current-limiting protector according to claim 1, wherein a safety voltage U0 is provided in the central control unit, and for the first load, the second load and the third load, when the real-time current of two of the three loads is greater than the second level current, the output voltage of the power supply is adjusted to 0.8 × U0, when the real-time current of two of the three loads is greater than the first level current and less than the second level current, the output voltage of the power supply is adjusted to 0.9 × U0, and if the circuit is safe, the output voltage of the power supply is a safety voltage U0.
3. The electric fire-protection current-limiting protector according to claim 2, wherein for an ith load branch, the real-time current of the load branch is detected within a preset time period T to obtain a current waveform pattern ii (T) within the period, a current waveform matrix (λ 1, λ 2, λ 3, … …, λ n) is arranged in the central control unit, λ 1 represents a first current waveform pattern, λ 2 represents a second current waveform pattern, λ 3 represents a third current waveform pattern, … …, λ n represents an nth current waveform pattern, and the detected real-time current value is correct if the obtained current waveform pattern ii (T) is within the current waveform matrix within the preset time period;
if the detected current waveform pattern ii (t) has a current value at N times that is not on any waveform pattern, the current waveform matrix pattern including the most points is selected as the actual current waveform pattern.
4. The electrical fire-protection current-limiting protector according to claim 3, wherein the loads are sorted according to the magnitude of the load current, the loads are used from small to large according to the load current, when the load with the minimum current is used for a preset time, a load circuit needs to be replaced, the next load to be used is judged, and the selection of the loads to be used is determined according to the sorting of the magnitude of the current of all the loads except the current load;
the safety voltage U0= current i0 x real time resistance of the sliding rheostat on the main circuit.
5. The electrical fire-protection current-limiting protector according to claim 3, wherein a standard current difference value is set in the central control unit, and within a preset time period, the current waveform diagram ii (t) is compared with any current waveform diagram in the current waveform matrix to obtain a waveform difference value, and at any time, if the waveform difference value is smaller than the standard current difference value, the current waveform diagram is an actual current waveform diagram;
if the waveform difference is greater than the standard current difference and the current waveform pattern ii (t) is close to any two waveform patterns in the current waveform matrix, the current waveform pattern ii (t) is the average value of any two waveform patterns after being superimposed.
6. The electrical fire-protection current-limiting protector according to claim 5, wherein a superimposed waveform is further provided in the central control unit, and when an actual current waveform needs to be adjusted, the actual current waveform and the superimposed waveform are superimposed as a correction to the real-time current.
7. The electrical fire-protection current-limiting protector according to claim 6, wherein for the ith load branch, if within a preset time period T, a current waveform pattern ii (T) within the period comprises m wave crests and n wave troughs, a wave crest matrix P (P1, P2, … Pm) and a wave trough matrix T (T1, T1, … Tn) are respectively determined, a wave crest mean value and a wave trough mean value are further set in the central control unit, if more than m/2 actual wave crest values are higher than the wave crest mean value within the preset period, the wave trough matrix is detected, and if more than n/2 actual wave trough values are lower than the wave trough mean value, the resistance value of the slide rheostat is adjusted, and the real-time voltage on the main circuit is reduced;
if the current waveform diagram ii (T) in the period comprises m wave crests and n wave troughs in a preset time period T, respectively determining a wave crest matrix P (P1, P2, … Pm) and a wave trough matrix T (T1, T1, … Tn), and also setting a wave crest mean value and a wave trough mean value in the central control unit, if less than m/3 actual wave crest values are higher than the wave crest mean value in the preset period, detecting a wave trough matrix, and if more than n/3 actual wave trough values are lower than the wave trough mean value, maintaining the real-time voltage on the main circuit;
if the current waveform diagram ii (T) in the period comprises m wave crests and n wave troughs in the preset time period T, respectively determining a wave crest matrix P (P1, P2, … Pm) and a wave trough matrix T (T1, T1, … Tn), and also setting a wave crest mean value and a wave trough mean value in the central control unit, if more than 3m/4 actual wave crest values are lower than the wave crest mean value in the preset period, detecting a wave trough matrix, and if more than 3n/4 actual wave trough values are higher than the wave trough mean value, improving the real-time voltage on the main circuit.
8. The electrical fire-protection current-limiting protector according to claim 1, wherein the switch module is an MOS transistor, and the resistance value of the sliding rheostat of the alternating current power source is in a range of 0-5k ohms.
9. An electrical fire-protection current-limiting protector according to any one of claims 1-8, wherein the central control unit is a central processor.
10. An electrical fire protection current limiting protector according to claim 9 wherein the primary current sensing device and the load current sensing device are automatic sensing devices.
CN202011059575.2A 2020-09-30 2020-09-30 Electric fire-proof current-limiting protector Active CN112186721B (en)

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