Control circuit and distribution box

Abstract

The invention discloses a control circuit and a power distribution box, and relates to the technical field of power distribution control, the control circuit comprises a first voltage sampling circuit, the sampling end of the first voltage sampling circuit is connected with the power supply input end; the sampling end of the first current sampling circuit is connected with a plurality of power supply output ends, and the main control circuit is connected with the output end of the first current sampling circuit and the output end of the first voltage sampling circuit; the controlled end of the switching circuit is electrically connected with the main control circuit, and the input end of the switching circuit is connected with the power supply input end; the invention aims to solve the technical problem that the protection function of the existing distribution box is relatively single.

Description

Technical Field

[0001] The present invention relates to the field of power distribution control technology, and in particular to a control circuit and a distribution box. Background Technology

[0002] As one of the main power distribution equipment in the electrical system, the main function of the distribution box is to branch the main distribution line and distribute the electric energy to various points. With the construction of smart grids and the continuous development of the power industry, the demand for distribution boxes is increasing, and distribution boxes are gradually becoming intelligent to meet different power needs while improving convenience and reliability.

[0003] The protection function of existing distribution boxes is usually relatively simple, mainly relying on the fuse to break the circuit when overvoltage or overcurrent occurs. However, once the fuse is blown, it needs to be replaced manually, which may cause a long power outage, and it is impossible to monitor and respond to changes in voltage and current in real time. SUMMARY OF THE INVENTION

[0004] The main purpose of the present invention is to provide a control circuit and a distribution box, aiming to solve the technical problem that the protection function of the existing distribution box is relatively single.

[0005] To achieve the above purpose, the present invention proposes a control circuit, which is applied to a distribution box, wherein the distribution box has a power input terminal and a power output terminal, and the control circuit comprises: A first voltage sampling circuit, wherein a sampling end of the first voltage sampling circuit is connected to the power input end, and the first voltage sampling circuit is used to collect the voltage of the power input end and output a first voltage sampling signal; A first current sampling circuit, wherein a sampling end of the first current sampling circuit is connected to the plurality of power supply output ends, and the first current sampling circuit is used to collect current magnitudes of the plurality of power supply output ends and output a first current sampling signal; A main control circuit, the main control circuit is connected to the output end of the first current sampling circuit and the output end of the first voltage sampling circuit; A switch circuit, wherein a controlled end of the switch circuit is electrically connected to the main control circuit, and an input end of the switch circuit is connected to the power input end; The main control circuit is used to control the switch circuit to turn on when it is determined according to the first voltage sampling signal that the voltage at the power input end is less than the first upper voltage threshold and greater than the first lower voltage threshold; and is also used to control the switch circuit to turn off when the voltage at the power input end is greater than the first upper voltage threshold or less than the first lower voltage threshold; The main control circuit is used to control the switch circuit to conduct the path between the power input terminal and the power output terminal when the current of the power output terminal is less than the first upper current threshold according to the first current sampling signal; and is also used to control the switch circuit to disconnect the path between the power input terminal and the power output terminal when the current of the power output terminal is greater than the first upper current threshold.

[0006] In one embodiment, the main control circuit is used to control the switch circuit to turn off and perform the first counting and the first timing when it is determined according to the first current sampling signal that the current at the power output end is greater than the first upper current threshold; The main control circuit is also used to control the switch circuit to be turned on when the first timing duration reaches a first duration; The main control circuit is also used to control the switch circuit to turn off when the value of the first count reaches a first value and the current at the power output end is greater than a first upper current threshold.

[0007] In one embodiment, the main control circuit is used to execute the second timing when it is determined according to the first current sampling signal that the current at the power output end is greater than the first upper current threshold, and stop the second timing when the current at the power output end is less than the first upper current threshold; The main control circuit is also used to control the switch circuit to turn off when it is determined that the current at the power output end is greater than the second upper current threshold value when the duration of multiple consecutive second timings is less than the second duration; The main control circuit is used to control the switch circuit to turn off when the second timing duration is greater than the second duration.

[0008] In one embodiment, the main control circuit is used to perform a second count when it is determined that the current at the power output end is greater than a first upper current threshold and the duration of the second timing is less than a second duration; The main control circuit is also used to control the switch circuit to turn off when the value of the second count reaches a second value.

[0009] In one embodiment, the main control circuit is further used to determine a change curve of the voltage at the power input end according to the voltage at the power input end; The main control circuit is further used to execute the third timing when the positive slope of the change curve is greater than the upper limit preset slope, and stop timing when the positive slope of the change curve is less than the upper limit preset slope; The main control circuit is further used for controlling the switch circuit to turn off when the third timing duration reaches the third duration and it is determined that the voltage of the power input terminal is greater than the second upper voltage threshold; and / or, The main control circuit is further used to execute the third timing when the negative slope of the change curve is greater than the upper limit preset slope, and stop timing when the negative slope of the change curve is less than the upper limit preset slope; The main control circuit is further used to control the switch circuit to turn off when the duration of the third timing reaches the third duration and it is determined that the voltage of the power input terminal is less than the second lower voltage threshold; Wherein, the second upper voltage threshold is less than the first upper voltage threshold, and the second lower voltage threshold is greater than the first lower voltage threshold.

[0010] In one embodiment, the main control circuit is further configured to execute a third count when the duration of the third timing is less than a third duration; The main control circuit is further used to control the switch circuit to turn off when the value of the third count is greater than the third value and the voltage of the power input terminal is greater than the second upper limit voltage threshold; and / or, The main control circuit is also used to control the switch circuit to turn off when the value of the third count is greater than the third value and the voltage of the power input terminal is less than the second lower voltage threshold.

[0011] In one embodiment, the distribution box has an equipment ground and a safety ground electrically connected to each other, and the control circuit further includes: A second voltage sampling circuit, wherein a sampling end of the second voltage sampling circuit is electrically connected to an intermediate node between the device ground and the safety ground, and an output end of the second voltage sampling circuit is electrically connected to the main control circuit; The second voltage sampling circuit is used to sample the leakage voltage between the device ground and the safety ground, and output a corresponding second voltage sampling signal; the main control circuit is used to control the switching circuit to be turned on / off according to the second voltage sampling signal; A second current sampling circuit, wherein the first sampling terminal of the second current sampling circuit is connected to the power input terminal, the second sampling terminal of the second current sampling circuit is connected to the power output terminal, and the output terminal of the second current sampling circuit is electrically connected to the main control circuit; The second current sampling circuit is used to sample the leakage current of the path between the power input terminal and the power output terminal, and output a corresponding second current sampling signal; the main control circuit is used to control the on / off of the switch circuit according to the second current sampling signal.

[0012] ​In one embodiment, the number of the power input terminals is multiple, the multiple power input terminals include a UPS power input terminal and multiple mains power input terminals, the number of the first voltage sampling circuits is multiple, and the sampling terminals of the multiple first voltage sampling circuits are connected to the UPS power input terminal and the multiple mains power input terminals in a one-to-one correspondence; The control circuit also includes: A switching circuit, wherein the first end of the switching circuit is respectively connected to the plurality of the mains power input ends and the UPS power input end, the second end of the switching circuit is connected to the power output end, and the controlled end of the switching circuit is electrically connected to the main control circuit; When the main control circuit determines that the voltages of multiple mains power input terminals are all less than the first lower voltage threshold according to multiple first voltage sampling signals, the main control circuit controls the switching circuit to conduct the path between the UPS power input terminal and the power output terminal, and disconnects the paths between the multiple mains power input terminals and the multiple power output terminals; When the main control circuit determines that the voltage of one of the mains power input terminals is less than the first lower voltage threshold according to the plurality of the first voltage sampling signals, the main control circuit controls the switching circuit to conduct the path between the other mains power input terminal and the power output terminal.

[0013] In one embodiment, the number of the power supply output terminals and the number of the first current sampling circuits are both multiple, and the switch circuit includes: A first switch component and a plurality of second switch components, wherein the first end of the first switch component is connected to the power input end, the second end of the first switch component is connected to the first ends of the plurality of second switch components, the second ends of the plurality of second switch components are connected to the plurality of power output ends in a one-to-one correspondence, and the sampling ends of the plurality of current sampling circuits are connected to the plurality of power output ends in a one-to-one correspondence; The main control circuit is used to control the first switch component to be turned on / off according to the first voltage sampling signal; The main control circuit is also used to control the second switch component connected to the corresponding power supply output terminal to turn on / off when it is determined that the current of at least one power supply output terminal is less than / greater than the first upper current threshold value according to the multiple current sampling signals.

[0014] The present invention also provides a distribution box, comprising a power input terminal, a power output terminal and a control circuit as described in any one of the above items; the control circuit is electrically connected to the power input terminal and the power output terminal respectively.

[0015] The technical solution of the present invention includes a first voltage sampling circuit, a first current sampling circuit, a main control circuit and a switch circuit. The main control circuit is used to control the switch circuit to disconnect the path between the power input terminal and the power output terminal when the voltage at the power input terminal is greater than the first upper voltage threshold / the current at the power output terminal is greater than the first upper current threshold, and is also used to control the switch circuit to conduct the path between the power input terminal and the power output terminal when the voltage at the power input terminal is less than the first lower voltage threshold or the current at the power output terminal is less than the first lower voltage threshold. In this way, through the first voltage sampling circuit and the first current sampling circuit, the distribution box using the control circuit of the present invention can monitor the voltage at the power input terminal and the current at the power output terminal in real time, and accurately control them according to the preset thresholds, thereby enriching the protection function of the distribution box, avoiding the cumbersome process of manual replacement of the fuse in the traditional distribution box after it is blown, and improving the reliability and convenience of power supply. Brief Description of the Figures

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without creative work.

[0017] Figure 1 is a schematic diagram of a module according to an embodiment of the present invention; Figure 2 is a schematic diagram of a module of another embodiment of the present invention; Figure 3 is a module schematic diagram of another embodiment of the present invention; Figure 4 This is a module schematic diagram of another embodiment of the present invention.

[0018] Description of Figure Numbers: 10. First voltage sampling circuit; 20. First current sampling circuit; 30. Main control circuit; 40. Switch circuit; 41, first switch component; 42, second switch component; 50, second voltage sampling circuit; 60, second current sampling circuit; 70, switching circuit.

[0019] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Specific implementation method

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] It should be noted that if there are directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention, the directional indications are only used to explain the relative position relationship and movement of the components in a certain posture. If the specific posture changes, the directional indications will also change accordingly.

[0022] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0023] As one of the main power distribution equipment in the electrical system, the main function of the distribution box is to branch the main distribution line and distribute the electric energy to various points. With the construction of smart grids and the continuous development of the power industry, the demand for distribution boxes is increasing, and distribution boxes are gradually becoming intelligent to meet different power needs while improving convenience and reliability.

[0024] The existing distribution box has a relatively simple protection function. Usually, only a protection fuse is set between the power input and power output ends, which is used to fuse in case of overvoltage / overcurrent to disconnect the path between the power input and power output ends. Once the fuse is blown, it needs to be replaced manually, which may cause a long power outage.

[0025] To this end, the present invention proposes a control circuit and a distribution box, aiming to solve the technical problem that the protection function of the existing distribution box is relatively single.

[0026] References Figure 1In one embodiment of the present invention, a control circuit is applied to a distribution box, the distribution box has a power input terminal and a power output terminal, and the control circuit includes: A first voltage sampling circuit 10, wherein a sampling end of the first voltage sampling circuit 10 is connected to the power input end, and the first voltage sampling circuit 10 is used to collect the voltage of the power input end and output a first voltage sampling signal; A first current sampling circuit 20, wherein the sampling end of the first current sampling circuit 20 is connected to the plurality of power supply output ends, and the first current sampling circuit 20 is used to collect the current magnitudes of the plurality of power supply output ends and output a first current sampling signal; A main control circuit 30, wherein the main control circuit 30 is connected to an output end of the first current sampling circuit 20 and an output end of the first voltage sampling circuit 10; A switch circuit 40, wherein a controlled end of the switch circuit 40 is electrically connected to the main control circuit 30, and an input end of the switch circuit 40 is connected to the power input end; The main control circuit 30 is used to control the switch circuit 40 to turn on when it is determined according to the first voltage sampling signal that the voltage at the power input end is less than the first upper voltage threshold and greater than the first lower voltage threshold; and is also used to control the switch circuit 40 to turn off when the voltage at the power input end is greater than the first upper voltage threshold or less than the first lower voltage threshold; The main control circuit 30 is used to control the switch circuit 40 to conduct the path between the power input terminal and the power output terminal when it is determined according to the first current sampling signal that the current at the power output terminal is less than the first upper current threshold; and is also used to control the switch circuit 40 to disconnect the path between the power input terminal and the power output terminal when the current at the power output terminal is greater than the first upper current threshold.

[0027] In this embodiment, the main control circuit 30 can be implemented by a main controller, such as MCU (Microcontroller Unit), DSP (Digital Signal Process), FPGA (Field Programmable Gate Array), SOC (System On Chip), etc.

[0028] In this embodiment, the switch circuit 40 can be implemented by at least one switch tube, such as a MOS tube, an IGBT tube, a thyristor, a triode, a power tube, etc., and / or by at least one switch device, such as a contactor, a circuit breaker and a relay. ​

[0029] In this embodiment, the first current sampling circuit 20 can be implemented by using a Hall current sensor, a current transformer or a resistive current sensor, and the first voltage sampling circuit 10 can be implemented by using a Hall voltage sensor, a voltage transformer or a resistive voltage sensor.

[0030] Specifically, the technical solution of the present invention includes a first voltage sampling circuit 10, a first current sampling circuit 20, a main control circuit 30 and a switch circuit 40. The main control circuit 30 is used to control the switch circuit 40 to disconnect the path between the power input terminal and the power output terminal when the voltage at the power input terminal is greater than the first upper voltage threshold / the current at the power output terminal is greater than the first upper current threshold, and is also used to control the switch circuit 40 to conduct the path between the power input terminal and the power output terminal when the voltage at the power input terminal is less than the first lower voltage threshold or the current at the power output terminal is less than the first lower voltage threshold. In this way, through the first voltage sampling circuit 10 and the first current sampling circuit 20, the distribution box using the control circuit of the present invention can monitor the voltage at the power input terminal and the current at the power output terminal in real time, and accurately control them according to the preset threshold, thereby enriching the protection function of the distribution box, avoiding the cumbersome process of manual replacement of the fuse in the traditional distribution box after it is blown, and improving the reliability and convenience of power supply. And the undervoltage protection function can also be achieved by adjusting the preset threshold.

[0031] There are two situations in which the current at the power output end is greater than the first upper current threshold. The first situation is that when the distribution box is connected to a high-power electrical appliance, the high-power electrical appliance requires a large current when it starts or works, causing the load current at the power output end to rise sharply. Or when the grid voltage fluctuates or the number of electrical equipment increases suddenly, the load current at the power output end may rise sharply. In such cases, the current surge is temporary and usually returns to normal after a period of time. The second situation is when the grid voltage is unstable for a long time, or there is an internal fault in the electrical equipment, such as a short circuit in the motor winding, a breakdown of the capacitor, etc., which may cause a sharp increase in the current consumed by the equipment, both of which will cause the current to be too large continuously.

[0032] Since the main control circuit 30 needs to control the switch circuit 40 to conduct again after a period of time (for example, 10 minutes) after the current is greater than the first upper current threshold, so that the first current sampling circuit 20 can sample the current at the power output end, thereby detecting the current, the second situation is applicable. However, in the first situation, the current will return to normal in a short time, but the switch circuit 40 will remain in the off state for a period of time, so that the distribution box will still stop supplying power to the load when the city power returns to normal, thereby causing unnecessary power supply interruption.

[0033] In one embodiment of the present invention, the main control circuit 30 is used to control the switch circuit 40 to turn off and perform the first counting and the first timing when it is determined according to the first current sampling signal that the current at the power output end is greater than the first upper current threshold; The main control circuit 30 is also used to control the switch circuit 40 to be turned on when the first timing duration reaches the first duration; The main control circuit 30 is also used to control the switch circuit 40 to turn off when the value of the first count reaches a first value and the current at the power output end is greater than a first upper current threshold.

[0034] In this embodiment, the purpose of controlling the switch circuit 40 to conduct when the first timing reaches the first time is to allow the first current sampling circuit 20 to sample the current after the current is greater than the first upper current threshold for a period of time, so as to determine whether the current has returned to normal after the first time (for example, 30S). When the current returns to normal, the main control circuit 30 controls the switch circuit 40 to conduct. In this way, by setting a reasonable delay (such as 30 seconds) after the current surges, and then sampling the current, it is possible to accurately determine whether the current has returned to normal, which helps to avoid unnecessary power supply interruptions caused by short-term current fluctuations, thereby improving the reliability and stability of power supply. In practical applications, it can reduce power supply interruptions caused by current fluctuations, the connection of high-power electrical appliances, or a sudden increase in electrical equipment, thereby improving the user's power usage experience.

[0035] Whenever the current is still greater than the first upper current threshold after the switch circuit 40 is turned on, the first count is increased by one. When the value of the first count is greater than the first value, it means that the current may remain at a high level for a long time (i.e., the second case mentioned above). Therefore, after the value of the first count is greater than the first value, the switch circuit 40 is controlled to cut off the path between the power input terminal and the power output terminal to prevent long-term excessive current from damaging the load. With this arrangement, when the current remains at a high level for a long time, it usually means that the load may be faulty or the grid voltage is unstable. Through the counting mechanism, when a certain counting threshold is reached, the switch circuit 40 is controlled to cut off the power supply, which can effectively prevent long-term high current from damaging the load equipment and extend the service life of the equipment.

[0036] ​The current at the power output end may fluctuate in some cases. For example, when a large number of electrical devices connected to the power output end are started or shut down at the same time, or the instability of the grid voltage may cause the current at the power output end to fluctuate frequently near the first upper current threshold, thereby erroneously triggering the switch circuit 40 to disconnect the path between the power input end and the power output end. In this way, the main control circuit 30 may control the switch circuit 40 to repeatedly turn on / off under the frequent fluctuation of the current. The frequent on / off actions (for example, controlling the switch current to turn on / off every 2S) will cause an impact on the electronic components inside the electrical equipment, which may cause damage to the components or shorten their lifespan.

[0037] In one embodiment of the present invention, the main control circuit 30 is used to perform the second timing when it is determined according to the first current sampling signal that the current at the power output end is greater than the first upper current threshold, and stop the second timing when the current at the power output end is less than the first upper current threshold; The main control circuit 30 is also used to control the switch circuit 40 to turn off when it is determined that the current at the power output end is greater than the second upper current threshold value when the duration of multiple consecutive second timings is less than the second duration; The main control circuit 30 is used to control the switch circuit 40 to turn off when the second timing duration is greater than the second duration.

[0038] In this embodiment, the purpose of the second timing is to record the duration of time when the current at the power output end is greater than the first upper limit current threshold. When the duration of the second timing is less than the second duration, it means that the current at the power output end fluctuates in a short time, and when the durations of multiple consecutive second timings are less than the second duration, it means that the current at the power output end fluctuates frequently over a long period of time. In this regard, the upper limit current threshold can be appropriately increased to the second upper limit current threshold (the second upper limit current threshold is set according to the specific situation to ensure that a certain current fluctuation can be tolerated and the equipment can be avoided from being damaged due to overload), so that the switch circuit 40 can be maintained in the on state during the time when the current frequently fluctuates, thereby ensuring continuous power supply to the load and reducing the impact on the electronic components inside the electrical equipment due to frequent on and off actions. When the second timing duration is longer than the second duration, it means that the current at the power output terminal has been maintained at a high level for a long time, or there is a continuous current fluctuation, which exceeds the short-term fluctuation range that the electrical equipment or the distribution box can tolerate. The reason for this situation may be that there is an abnormality in the load connected to the power output terminal, such as a failure of an electrical equipment causing the current to be continuously too high, or although multiple devices are not started at the same time, their total power consumption has exceeded the rated output capacity of the distribution box. In this regard, the main control circuit 30 controls the switch circuit 40 to cut off the path between the power input terminal and the power output terminal when the second timing duration is longer than the second duration, so as to avoid the continuous excessive current from damaging the electrical equipment.

[0039] In one embodiment of the present invention, the main control circuit 30 is used to perform a second count when it is determined that the current at the power output end is greater than the first upper current threshold and the duration of the second timing is less than the second duration; The main control circuit 30 is also used to control the switch circuit 40 to turn off when the value of the second count reaches the second value.

[0040] In this embodiment, the purpose of the second count is to record the number of times that the current at the power output terminal is greater than the first upper current threshold and the duration of the second count is less than the second duration. When the value of the second count reaches the second value, it indicates that the current at the power output terminal fluctuates frequently for a long time, and the magnitude may be maintained near the first upper current threshold. The frequent fluctuation of the current near the first upper current threshold for a long time may cause damage to the load connected to the power output terminal. In this regard, the main control circuit 30 controls the switch circuit 40 to disconnect the path between the power input terminal and the power output terminal when the value of the second count reaches the second value, so as to prevent the frequently fluctuating current from causing damage to the load.

[0041] With such a configuration, compared with the existing distribution box, the distribution box using the control circuit of the present invention can start or shut down a large number of electrical devices connected to the power output end at the same time, or when the unstable grid voltage causes the current to fluctuate frequently in a short time, it can maintain continuous power supply to the load, thereby avoiding damage to the load caused by frequent on / off of the switch circuit 40. It can also control the switch circuit 40 to shut down when the current fluctuates frequently for a long time, thereby avoiding damage to the load caused by the current fluctuating frequently for a long time.

[0042] Since it takes a certain amount of time for the main control circuit 30 to control the switch circuit 40 to turn on / off from responding to the sampling signal, the switch circuit 40 cannot be turned off in time when the voltage is greater than the first upper voltage threshold. The voltage may be in an overvoltage state during the process from the main control circuit 30 responding to the first voltage sampling signal to controlling the switch circuit 40 to turn off, causing overheating, damage or performance degradation of the internal components of the electrical equipment, especially for some sophisticated electronic equipment, such as computers, communication equipment, etc. In this regard, the main control circuit 30 needs to control the switch circuit 40 to disconnect the path between the power input terminal and the power output terminal before the voltage is greater than the first upper voltage threshold.

[0043] In one embodiment of the present invention, the main control circuit 30 is further used to determine a change curve of the voltage at the power input end according to the voltage at the power input end; The main control circuit 30 is also used to perform a third timing when the positive slope of the change curve is greater than the upper preset slope, and stop timing when the positive slope of the change curve is less than the upper preset slope; The main control circuit 30 is further used to control the switch circuit 40 to turn off when the third timing duration reaches the third duration and it is determined that the voltage at the power input end is greater than the second upper voltage threshold; and / or, The main control circuit 30 is also used to perform a third timing when the negative slope of the change curve is greater than the upper preset slope, and stop timing when the negative slope of the change curve is less than the upper preset slope; The main control circuit 30 is further used to control the switch circuit 40 to turn off when the duration of the third timing reaches the third duration and it is determined that the voltage of the power input end is less than the second lower voltage threshold; Wherein, the second upper voltage threshold is less than the first upper voltage threshold, and the second lower voltage threshold is greater than the first lower voltage threshold.

[0044] In this embodiment, the main control circuit 30 calculates the voltage change curve over time based on the first voltage sampling signal through Fourier transform analysis. The change curve describes the rising or falling trend of the voltage and the rate of change (i.e., positive slope or negative slope).

[0045] In this embodiment, when the positive slope of the change curve is greater than the upper preset slope, it means that the voltage is growing too fast. The purpose of the third timing is to record the duration of the slope of the change curve greater than the upper preset slope. When the duration of the third timing reaches the preset duration and the voltage at the power input terminal is greater than the second upper voltage threshold (the second upper voltage threshold is less than the first upper voltage threshold), it means that the voltage is approaching the first upper voltage threshold while maintaining a high growth rate. In this regard, the main control circuit 30 needs to control the switch circuit 40 to disconnect the path between the power input terminal and the power output terminal when the duration of the third timing reaches the third duration and the voltage is greater than the second upper voltage threshold, that is, to shut down the path between the power input terminal and the power output terminal before the voltage reaches the first upper voltage threshold, so as to avoid the delay control of the main control circuit 30 causing excessively high voltage to damage the electrical equipment. Similarly, the main control circuit 30 controls the switch circuit 40 to shut down when the negative slope of the change curve is greater than the upper preset slope for a third duration and the voltage is less than the second lower voltage threshold, so as to avoid the performance degradation of the electrical equipment caused by undervoltage and affect the normal operation of the electrical equipment. Since the main control circuit 30 responds to the first voltage sampling signal in advance before the voltage is greater than the first upper voltage threshold or less than the first lower voltage threshold, the advance time is offset by the delay control of the main control circuit 30, so the switch circuit 40 can be controlled to shut down in time when the voltage is greater than the first upper voltage threshold or less than the first lower voltage threshold. With such a configuration, when the control circuit of the present invention is applied to a distribution box, it can disconnect the path between the power input terminal and the power output terminal in time when the voltage at the power input terminal is greater than the first upper voltage threshold or less than the first lower voltage threshold, avoiding the influence of overvoltage or undervoltage at the power input terminal on the electrical equipment caused by delayed shutdown.

[0046] In one embodiment of the present invention, the main control circuit 30 is further configured to execute a third count when the duration of the third timing is less than a third duration; The main control circuit 30 is also used to control the switch circuit 40 to turn off when the value of the third count is greater than the third value and the voltage of the power input terminal is greater than the second upper limit voltage threshold; and / or, The main control circuit 30 is also used to control the switch circuit 40 to turn off when the value of the third count is greater than the third value and the voltage of the power input terminal is less than the second lower voltage threshold.

[0047] In this embodiment, when the duration of the third timing is less than the third duration, it indicates that the positive slope / negative slope of the change curve increases first and then decreases in a short time. When the value of the third count is greater than the third value and the voltage at the power input terminal is greater than the second upper voltage threshold, it indicates that the voltage change trend may be intermittent rise (that is, the voltage fluctuates between rise and fall, but the overall trend is rising) and is close to the first upper voltage threshold. In this case, the main control circuit 30 needs to control the switch circuit 40 to disconnect the path between the power input terminal and the power output terminal to avoid overvoltage affecting the electrical equipment. Similarly, when the value of the third count is greater than the third value and the voltage at the power input terminal is less than the second lower voltage threshold, it indicates that the voltage change trend may be intermittent decline and is close to the first lower voltage threshold. In this case, the main control circuit 30 needs to control the switch circuit 40 to disconnect the path between the power input terminal and the power output terminal to avoid undervoltage affecting the electrical equipment. With such a configuration, in practical applications, when the load change of the power grid is periodic or irregular, the voltage at the power input terminal may fluctuate between rising and falling, and present an overall upward trend. The distribution box using the control circuit of the present invention can disconnect the path between the power input terminal and the power output terminal when the voltage presents an overall upward trend and approaches the first upper voltage threshold, thereby avoiding damage to electrical equipment caused by overvoltage or undervoltage.

[0048] References Figure 2 , in one embodiment of the present invention, the distribution box has an equipment ground and a safety ground electrically connected to each other, and the control circuit further includes: A second voltage sampling circuit 50, wherein a sampling end of the second voltage sampling circuit 50 is electrically connected to an intermediate node between the device ground and the safety ground, and an output end of the second voltage sampling circuit 50 is electrically connected to the main control circuit 30; The second voltage sampling circuit 50 is used to sample the leakage voltage between the device ground and the safety ground, and output a corresponding second voltage sampling signal; the main control circuit 30 is used to control the switch circuit 40 to turn on / off according to the second voltage sampling signal; A second current sampling circuit 60, wherein a first sampling terminal of the second current sampling circuit 60 is connected to the power input terminal, a second sampling terminal of the second current sampling circuit 60 is connected to the power output terminal, and an output terminal of the second current sampling circuit 60 is electrically connected to the main control circuit 30; The second current sampling circuit 60 is used to sample the leakage current of the path between the power input terminal and the power output terminal, and output a corresponding second current sampling signal; the main control circuit 30 is used to control the switch circuit 40 to turn on / off according to the second current sampling signal.

[0049] In this embodiment, if the internal components of the distribution box, such as circuit breakers and contactors, have insulation damage, poor contact, and other faults, the leakage voltage between the equipment ground and the safety ground may be too large (for example, greater than 32V~40V). The excessive leakage voltage may cause the electronic components inside the distribution box to work abnormally, thereby affecting the overall function of the distribution box. When there are aging devices or poor insulation inside the distribution box, leakage current may occur between the power input terminal and the power output terminal. When the leakage current is greater than a preset threshold (for example, 95 mA~105 mA), it will penetrate the insulation layer and leak to the outside. In this regard, the leakage voltage between the equipment ground and the safety ground is sampled by the second voltage sampling circuit 50, and the leakage current between the power input terminal and the power output terminal is sampled by the second current sampling circuit 60. When the main control circuit 30 detects that the leakage voltage / leakage current is too large, it controls the switch circuit 40 to disconnect the path between the power input terminal and the power output terminal, so as to avoid the situation where the leakage voltage / leakage current is too large and causes the distribution box to fail, and indirectly affects the electrical equipment.

[0050] References Figure 3 , in one embodiment of the present invention, the number of the power input terminals is multiple, including a UPS power input terminal and a plurality of mains power input terminals, the number of the first voltage sampling circuits 10 is multiple, and the sampling terminals of the multiple first voltage sampling circuits 10 are connected to the UPS power input terminal and the multiple mains power input terminals in a one-to-one correspondence; The control circuit also includes: Switching circuit 70, wherein the first end of the switching circuit 70 is respectively connected to the plurality of mains power input ends and the UPS power input end, the second end of the switching circuit 70 is connected to the power output end, and the controlled end of the switching circuit 70 is electrically connected to the main control circuit 30; When the main control circuit 30 determines that the voltages of multiple mains power input terminals are all less than the first lower voltage threshold according to multiple first voltage sampling signals, the main control circuit 30 controls the switching circuit 70 to conduct the path between the UPS power input terminal and the power output terminal, and disconnects the paths between the multiple mains power input terminals and the multiple power output terminals; When the main control circuit 30 determines that the voltage of one of the mains power input terminals is less than the first lower voltage threshold according to the plurality of the first voltage sampling signals, the switching circuit 70 controls the switching circuit 70 to conduct the path between the voltage of another mains power input terminal and the power output terminal.

[0051] In this embodiment, the switching circuit 70 can be implemented by using multiple relays or multiple single-pole single-throw switches and other switch components. When the switching circuit 70 uses multiple relays, the first ends of the multiple relays are connected to the multiple power input ends one by one, and the second ends of the multiple relays are connected to the power output ends. The main control circuit 30 can control any relay to be turned on / off, so that the path between the power input end and the power output end corresponding to the relay is turned on.

[0052] In this embodiment, the UPS power input terminal is connected to the UPS power supply, and the mains power input terminal is connected to the mains.

[0053] In this embodiment, when the mains power is supplied normally, the main control circuit 30 selects one of the mains power input terminals as the main power supply by controlling the switching circuit 70 to provide power to the electrical equipment. When the main control circuit 30 detects through the first voltage sampling circuit 10 that the mains power of the current main power supply is out of power or undervoltage, the main control circuit 30 controls the path between the mains power input terminal currently serving as the main power supply and the power output terminal to be disconnected, and turns on the path between another mains power input terminal (serving as a backup power supply) and the power output terminal, thereby maintaining continuous power supply to the electrical equipment. When the mains connected to multiple mains power input terminals are all out of power or undervoltage, the main control circuit 30 controls the switching circuit 70 to turn on the path between the UPS power input terminal and the power output terminal. As an uninterruptible power supply, the UPS power supply can provide stable power when the mains power is interrupted or the voltage is undervoltage, thereby ensuring that the electrical equipment can continue to operate.

[0054] References Figure 4 , in one embodiment of the present invention, the number of the power supply output terminals and the number of the first current sampling circuits 20 are both multiple, and the switch circuit 40 includes: A first switch component 41 and a plurality of second switch components 42, wherein the first end of the first switch component 41 is connected to the power input end, the second end of the first switch component 41 is connected to the first ends of the plurality of second switch components 42, the second ends of the plurality of second switch components 42 are connected to the plurality of power output ends in a one-to-one correspondence, and the sampling ends of the plurality of current sampling circuits are connected to the plurality of power output ends in a one-to-one correspondence; The main control circuit 30 is used to control the first switch component 41 to be turned on / off according to the first voltage sampling signal; The main control circuit 30 is also used to control the second switch component 42 connected to the corresponding power supply output terminal to be turned on / off when it is determined that the current of at least one power supply output terminal is less than / greater than the first upper current threshold according to the multiple current sampling signals; In the present embodiment, the first switch component 41 and the second switch component 42 can be implemented by using bidirectional switch components such as relays or single-pole single-throw switches.​

[0055] In this embodiment, multiple power output terminals can be connected to multiple different power-consuming devices respectively. When the current of at least one power output terminal is greater than the first upper current threshold, the main control circuit 30 controls the corresponding second switch component 42 to disconnect to prevent excessive current from damaging the power-consuming device, and controls the second switch component 42 to conduct the path between the power input terminal and the corresponding power output terminal when the current returns to normal.

[0056] In one embodiment of the present invention, the control circuit further includes: A trigger circuit, the output end of which is electrically connected to the main control circuit 30, and the trigger circuit is used to output a corresponding trigger signal when triggered; The main control circuit 30 is used to control the corresponding second switch component 42 to turn on / off according to the trigger signal.

[0057] In this embodiment, the trigger circuit includes multiple trigger components (buttons or knobs), and the multiple trigger components are electrically connected to the main control circuit 30. When the trigger component is triggered, the trigger component outputs a trigger signal to the main control circuit 30, and the main control circuit 30 controls the corresponding second switch component 42 to turn on / off according to the trigger signal, thereby realizing power supply control of the electrical equipment. With such a setting, in actual applications, the user can trigger the button on the distribution box according to actual needs to turn on / off the path between the corresponding electrical equipment and the mains. For example, when a heater needs to be used, the path between the heater and the mains is turned on to make the heater work.

[0058] In this embodiment, the control circuit also includes a wireless communication module for establishing a wireless communication connection between the main control circuit 30 and the host computer. In this way, the user does not need to go to the location of the distribution box in person, and can remotely control the first switch component 41 and the second switch component 42 through the host computer. For example, in a smart home, the user can remotely control the lamps, air conditioners and other equipment in the home through a host computer such as a mobile phone to start the lamps and air conditioners. The user can also intuitively view the voltage at the power input end and the current at the power output end through the host computer, so as to timely understand the city power situation and the energy consumption of the electrical equipment.

[0059] In one embodiment of the present invention, the control circuit further includes an alarm module, which is electrically connected to the main control circuit 30. The alarm module is used to issue an alarm action such as an audible alarm, a light alarm or a vibration alarm when the voltage at the power input terminal is greater than the first upper voltage threshold or the current at the power output terminal is greater than the first upper current threshold, and stop the alarm after the current or voltage returns to normal.

[0060] The present invention also proposes a distribution box, comprising a power input terminal, a power output terminal and the control circuit as described above; the control circuit is electrically connected to the power input terminal and the power output terminal respectively.

[0061] It is worth noting that, since the distribution box of the present invention is based on the above-mentioned control circuit, the embodiments of the distribution box of the present invention include all technical solutions of all embodiments of the above-mentioned control circuit, and the technical effects achieved are also exactly the same, which will not be repeated here.

[0062] The above description is only an exemplary embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A control circuit, applied to a distribution box, wherein the distribution box has a power input terminal and a power output terminal, characterized in that: The control circuit comprises: a first voltage sampling circuit, wherein a sampling terminal of the first voltage sampling circuit is connected to the power input terminal, and the first voltage sampling circuit is used to collect the voltage of the power input terminal and output a first voltage sampling signal; A first current sampling circuit, wherein a sampling end of the first current sampling circuit is connected to the plurality of power output ends, and the first current sampling circuit is used to collect current magnitudes of the plurality of power output ends and output a first current sampling signal; A main control circuit, wherein the main control circuit is connected to an output end of the first current sampling circuit and an output end of the first voltage sampling circuit; A switch circuit, wherein a controlled end of the switch circuit is electrically connected to the main control circuit, and an input end of the switch circuit is connected to the power input end; The main control circuit is used to control the switch circuit to turn on when it is determined according to the first voltage sampling signal that the voltage at the power input end is less than the first upper voltage threshold and greater than the first lower voltage threshold; and is also used to control the switch circuit to turn off when the voltage at the power input end is greater than the first upper voltage threshold or less than the first lower voltage threshold; The main control circuit is used to control the switch circuit to turn on the path between the power input terminal and the power output terminal when it is determined according to the first current sampling signal that the current at the power output terminal is less than a first upper current threshold; and is also used to control the switch circuit to disconnect the path between the power input terminal and the power output terminal when the current at the power output terminal is greater than the first upper current threshold.

2. The control circuit according to claim 1, characterized in that: The main control circuit is used to control the switch circuit to turn off and perform a first count and a first timing when it is determined according to the first current sampling signal that the current at the power output end is greater than a first upper current threshold; The main control circuit is also used to control the switch circuit to be turned on when the first timing duration reaches a first duration; The main control circuit is further configured to control the switch circuit to turn off when the value of the first count reaches a first value and the current at the power output end is greater than a first upper current threshold.

3. The control circuit according to claim 1, characterized in that: The main control circuit is used to execute the second timing when it is determined according to the first current sampling signal that the current at the power output end is greater than the first upper current threshold, and stop the second timing when the current at the power output end is less than the first upper current threshold; The main control circuit is also used for controlling the switch circuit to turn off when it is determined that the current at the power output end is greater than the second upper current threshold value when the durations of multiple consecutive second timings are all less than the second duration; The main control circuit is used for controlling the switch circuit to turn off when the second timing duration is greater than the second duration.

4. The control circuit according to claim 3, characterized in that: The main control circuit is used to perform a second count when it is determined that the current at the power output end is greater than a first upper current threshold and the duration of the second timing is less than a second duration; The main control circuit is further configured to control the switch circuit to turn off when the value of the second count reaches a second value.

5. The control circuit according to claim 1, characterized in that: The main control circuit is also used to determine a change curve of the voltage at the power input end according to the voltage at the power input end; The main control circuit is also used to perform a third timing when the positive slope of the change curve is greater than the upper preset slope, and stop timing when the positive slope of the change curve is less than the upper preset slope; The main control circuit is further used for controlling the switch circuit to turn off when the duration of the third timing reaches the third duration and it is determined that the voltage of the power input terminal is greater than the second upper voltage threshold; and / or, The main control circuit is further used to execute the third timing when the negative slope of the change curve is greater than the upper preset slope, and stop timing when the negative slope of the change curve is less than the upper preset slope; The main control circuit is further used for controlling the switch circuit to turn off when the duration of the third timing reaches the third duration and it is determined that the voltage of the power input terminal is less than the second lower voltage threshold; The second upper voltage threshold is smaller than the first upper voltage threshold, and the second lower voltage threshold is larger than the first lower voltage threshold.

6. The control circuit according to claim 5, characterized in that: The main control circuit is further configured to execute a third counting when the duration of the third timing is less than a third duration; The main control circuit is also used to control the switch circuit to turn off when the value of the third count is greater than the third value and the voltage of the power input terminal is greater than the second upper limit voltage threshold; and / or, The main control circuit is further configured to control the switch circuit to turn off when the value of the third count is greater than a third value and the voltage at the power input terminal is less than a second lower voltage threshold.

7. The control circuit according to claim 1, characterized in that: The distribution box has an equipment ground and a safety ground electrically connected to each other, and the control circuit further comprises: a second voltage sampling circuit, wherein a sampling terminal of the second voltage sampling circuit is electrically connected to an intermediate node between the device ground and the safety ground, and an output terminal of the second voltage sampling circuit is electrically connected to the main control circuit; The second voltage sampling circuit is used to sample the leakage voltage between the device ground and the safety ground, and output a corresponding second voltage sampling signal; the main control circuit is used to control the switching circuit to be turned on / off according to the second voltage sampling signal; a second current sampling circuit, wherein a first sampling terminal of the second current sampling circuit is connected to the power input terminal, a second sampling terminal of the second current sampling circuit is connected to the power output terminal, and an output terminal of the second current sampling circuit is electrically connected to the main control circuit; The second current sampling circuit is used to sample the leakage current of the path between the power input terminal and the power output terminal, and output a corresponding second current sampling signal; the main control circuit is used to control the on / off of the switch circuit according to the second current sampling signal.

8. The control circuit according to any one of claims 1 to 7, characterized in that: There are multiple power input terminals, including a UPS power input terminal and multiple mains power input terminals. There are multiple first voltage sampling circuits, and the sampling terminals of the multiple first voltage sampling circuits are connected to the UPS power input terminal and the multiple mains power input terminals in a one-to-one correspondence. The control circuit further comprises: A switching circuit, wherein a first end of the switching circuit is respectively connected to the plurality of mains power input ends and the UPS power input end, a second end of the switching circuit is connected to the power output end, and a controlled end of the switching circuit is electrically connected to the main control circuit; When the main control circuit determines that the voltages of the plurality of mains power input terminals are all less than the first lower voltage threshold according to the plurality of the first voltage sampling signals, the main control circuit controls the switching circuit to conduct the path between the UPS power input terminal and the power output terminal, and disconnect the paths between the plurality of the mains power input terminals and the plurality of the power output terminals; When the main control circuit determines that the voltage of one of the mains power input terminals is less than a first lower voltage threshold according to a plurality of the first voltage sampling signals, the main control circuit controls the switching circuit to conduct a path between another mains power input terminal and the power output terminal.

9. The control circuit according to any one of claims 1 to 7, characterized in that: The number of the power supply output terminals and the number of the first current sampling circuits are both multiple, and the switch circuit includes: A first switch component and a plurality of second switch components, wherein the first end of the first switch component is connected to the power input end, the second end of the first switch component is connected to the first ends of the plurality of second switch components, the second ends of the plurality of second switch components are connected to the plurality of power output ends in a one-to-one correspondence, and the sampling ends of the plurality of current sampling circuits are connected to the plurality of power output ends in a one-to-one correspondence; The main control circuit is used to control the first switch component to be turned on / off according to the first voltage sampling signal; The main control circuit is also used to control the second switch component connected to the corresponding power supply output terminal to turn on / off when it is determined that the current of at least one of the power supply output terminals is less than / greater than a first upper limit current threshold based on multiple current sampling signals.

10. A distribution box, characterized in that: It comprises a power input terminal, a power output terminal and a control circuit as described in any one of claims 1 to 9; the control circuit is electrically connected to the power input terminal and the power output terminal respectively.

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