Outdoor distribution box power failure reason detection circuit

Abstract

The invention relates to a power failure reason detection circuit for an outdoor distribution box, and the circuit comprises a commercial power voltage detection circuit which is disposed at a load end of a transformer of the outdoor distribution box; the air switch state detection circuit is arranged at the load end of a transformer of the outdoor distribution box; the main control module is used for detecting the state of an air switch at the load end of the transformer through the air switch state detection circuit when the mains supply voltage detection circuit detects that the load equipment of the outdoor distribution box is powered off, and sending a detection result to the upper computer; and the communication circuit is connected to the main control module. A maintainer can timely know the power failure of the corresponding outdoor distribution box through the upper computer, and can judge the power failure reason of the distribution box according to the air switch, so that the maintainer can timely formulate a corresponding maintenance plan and then carry out maintenance on site, and the maintenance efficiency of the maintainer is improved.

Description

Technical Field

[0001] The present application relates to the field of distribution boxes, and particularly to a detection circuit for the power outage reason of an outdoor distribution box. Background Art

[0002] A distribution box is a control center that rationally distributes electric energy among various components in a power supply line. It is a control link that reliably receives the upper-end power supply and correctly feeds out the load electric energy, and is also the key to obtaining whether users are satisfied with the power supply quality. The distribution box distributes electric energy for load devices by accessing the commercial power.

[0003] When the distribution box has a power outage, maintenance personnel need to reach the site to confirm the reason for the power outage of the distribution box, and then formulate a maintenance plan. It is impossible to achieve that after the maintenance personnel can timely know the reason for the power outage, formulate a maintenance plan, and then reach the site for maintenance, resulting in low maintenance efficiency. Summary of the Invention

[0004] In view of the above problems, the present application provides a detection circuit for the power outage reason of an outdoor distribution box, which solves the problem that after the existing distribution box has a power outage, it is impossible to achieve that after the maintenance personnel can timely know the reason for the power outage, formulate a maintenance plan, and then reach the site for maintenance, resulting in low maintenance efficiency.

[0005] To achieve the above object, the inventor provides a detection circuit for the power outage reason of an outdoor distribution box, including:

[0006] A commercial power voltage detection circuit, which is arranged at the load end of the transformer of the outdoor distribution box, and is used to detect whether the load device of the outdoor distribution box has a power failure;

[0007] An air switch state detection circuit, which is arranged at the load end of the transformer of the outdoor distribution box, and is used to detect the state of the air switch at the load end of the transformer;

[0008] A main control module, which is connected to the commercial power voltage detection circuit and the air switch state detection circuit. When the main control module detects that the load device of the outdoor distribution box has a power failure through the commercial power voltage detection circuit, it detects the state of the air switch at the load end of the transformer through the air switch state detection circuit, and sends the detected result to the host computer;

[0009] A communication circuit, which is connected to the main control module, and is used for information interaction between the main control module and the host computer;

[0010] A power supply circuit, which is connected to the air switch state detection circuit and the main control module, and is used to supply power to the air switch state detection circuit and the main control module.

[0011] In some embodiments, the mains voltage detection circuit includes a first voltage-dividing resistor and a second voltage-dividing resistor;

[0012] One end of the first voltage-dividing resistor is connected to one end of the load device, the other end of the first voltage-dividing resistor is connected to the main control unit and one end of the second voltage-dividing resistor, and the other end of the second voltage-dividing resistor is grounded.

[0013] In some embodiments, the air switch state detection circuit includes a switching element, a third resistor, a fourth resistor, and a fifth resistor;

[0014] One end of the switching element is connected to the power supply circuit, the other end of the switching element is connected to one end of the third resistor, and the control end of the switching element is connected to the main control module;

[0015] The other end of the third resistor is connected to one end of the load device;

[0016] One end of the fourth resistor is connected to the other end of the load device, and the other end of the fourth resistor is grounded;

[0017] One end of the fifth resistor is connected to the other end of the load device, and the other end of the fifth resistor is connected to the main control module;

[0018] The main control module is further configured to, when the load device loses power, by controlling the switching element to turn on, calculate the impedance of the load device loop according to the voltage value fed back by the fifth resistor, and judge the state of the air switch at the load end of the transformer according to the calculated impedance.

[0019] In some embodiments, the main control module is further configured to, when the load device loses power, after controlling the switching element to turn on and delaying a preset time, collect the DC voltage value fed back by the fifth resistor, and calculate the DC impedance of the load device loop according to the DC voltage value; and control the switching element to intermittently turn on at a first preset frequency, collect the first AC voltage value fed back by the fifth resistor, calculate the first AC impedance of the load device loop according to the first AC voltage value, control the switching element to intermittently turn on at a second preset frequency, collect the second AC voltage value fed back by the fifth resistor, calculate the second AC impedance of the load device loop according to the second AC voltage value, and judge the state of the air switch at the load end of the transformer according to the calculated DC impedance, first AC impedance, and second AC impedance.

[0020] In some embodiments, the switching element is a MOS transistor.

[0021] In some embodiments, a super capacitor and a diode are further included. One end of the super capacitor is connected to the cathode of the diode and the power input terminal of the main control module, the other end of the super capacitor is grounded, and the anode of the diode is connected to the power supply circuit.

[0022] In some embodiments, a zero-sequence current transformer is further included.

[0023] The zero-sequence current transformer is disposed at the load end of the transformer of the outdoor distribution box, and the zero-sequence current transformer is connected to the main control module. The zero-sequence current transformer is used to detect the leakage current of the load device.

[0024] In some embodiments, a current transformer is further included. The current transformer is disposed at the load end of the transformer of the outdoor distribution box, and the current transformer is connected to the main control module. The current transformer is used to detect the working current of the load device.

[0025] In some embodiments, an indicator light is further included, and the indicator light is connected to the main control module.

[0026] In some embodiments, the main control module is a main control single-chip microcomputer.

[0027] Different from the prior art, in the above technical solution, the power supply circuit is connected to the air switch state detection circuit and the main control module for power supply. The main control module detects whether the load device of the outdoor distribution box loses power through the mains voltage detection circuit disposed at the load end of the transformer of the outdoor distribution box. If it is detected that the load device of the outdoor distribution box loses power, the air switch state detection circuit disposed at the load end of the transformer of the outdoor distribution box is started to detect the state of the air switch at the load end of the transformer, and then the detection result is sent to the upper computer through the communication circuit, so that when the load device of the outdoor distribution box loses power, the maintenance personnel can know in time through the upper computer that the corresponding outdoor distribution box is powered off. By judging the power-off reason of the distribution box according to the air switch, the maintenance personnel can formulate a corresponding maintenance plan in time and then go to the site for maintenance, improving the maintenance efficiency of the maintenance personnel.

[0028] The above relevant records of the invention content are only an overview of the technical solution of this application. In order to enable those of ordinary skill in the art to more clearly understand the technical solution of this application, and then can be implemented according to the content recorded in the text of the specification and the drawings, and in order to make the above objects, other objects, features and advantages of this application more easily understood, the following is described in conjunction with the specific embodiments and drawings of this application. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The drawings are only used to illustrate the principles, implementation methods, applications, features and effects of the specific embodiments of this application and other related contents, and should not be regarded as a limitation to this application.

[0030] In the accompanying drawings of the specification:

[0031] Figure 1It is a schematic structural diagram of the outdoor distribution box power outage cause detection circuit described in the specific implementation manner;

[0032] Figure 2 It is a circuit schematic diagram of the outdoor distribution box power outage cause detection circuit described in the specific implementation manner;

[0033] Figure 3 It is an equivalent circuit schematic diagram of the load device loop when the air switch is disconnected described in the specific implementation manner

[0034] Figure 4 It is an equivalent circuit schematic diagram of the load device loop when the air switch is closed described in the specific implementation manner

[0035] Figure 5 It is a schematic flow diagram of the outdoor distribution box power outage cause detection method described in the specific implementation manner.

[0036] The description of the reference numerals involved in the above-mentioned drawings is as follows:

[0037] 110, mains voltage detection circuit,

[0038] 120, air switch status detection circuit;

[0039] 130, main control module,

[0040] 140, communication circuit,

[0041] 150, power supply circuit,

[0042] 160, super capacitor backup power circuit,

[0043] 170, zero-sequence current transformer,

[0044] 180, current transformer,

[0045] 190, indicator light. Specific implementation manner

[0046] To describe in detail the possible application scenarios, technical principles, implementable specific solutions, achievable purposes and effects, etc. of the present application, the following will be described in detail in conjunction with the listed specific examples and with reference to the drawings. The examples described herein are only used to more clearly illustrate the technical solutions of the present application, so they are only examples and cannot be used to limit the protection scope of the present application.

[0047] Reference to "embodiment" in this document means that the specific features, structures, or characteristics described in connection with the embodiment may be included in at least one embodiment of this application. The term "embodiment" appearing at various positions in the specification does not necessarily refer to the same embodiment, nor does it particularly limit its independence or relevance to other embodiments. In principle, in this application, as long as there is no technical contradiction or conflict, the various technical features mentioned in each embodiment can be combined in any way to form corresponding implementable technical solutions.

[0048] Unless otherwise defined, the meanings of the technical terms used in this document are the same as those commonly understood by those skilled in the technical field to which this application belongs; the use of the relevant terms in this document is only for describing specific embodiments and is not intended to limit this application.

[0049] In the description of this application, the phrase "and / or" is an expression used to describe the logical relationship between objects, indicating that three relationships may exist. For example, A and / or B means: the existence of A, the existence of B, and the simultaneous existence of A and B. In addition, the character " / " in this document generally represents an "or" logical relationship between the associated objects before and after.

[0050] In this application, terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual quantitative, primary-secondary, or sequential relationship between these entities or operations.

[0051] Without further limitation, in this application, the expressions "comprising", "including", "having", or other similar expressions used in a statement are intended to cover non-exclusive inclusion. These expressions do not exclude the possibility that there may be additional elements in the process, method, or product including the said elements, such that a process, method, or product including a series of elements may include not only those defined elements, but also other elements not explicitly listed, or elements inherent to such process, method, or product.

[0052] Similar to the understanding in the Examination Guidelines, in this application, expressions such as "greater than", "less than", "exceeding", etc. are understood not to include the number itself; expressions such as "above", "below", "within", etc. are understood to include the number itself. In addition, in the description of the embodiments of this application, the meaning of "a plurality of" is two or more (including two), and similar expressions related to "many", such as "multiple groups", "multiple times", etc., are understood in the same way, unless otherwise specifically defined.

[0053] In the description of the embodiments of the present application, the spatially related expressions used, such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "perpendicular", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the specific embodiment or the attached drawings. It is only for the convenience of describing the specific embodiments of the present application or for the reader's understanding, rather than indicating or implying that the device or component referred to must have a specific position, a specific orientation, or be constructed or operated in a specific orientation. Therefore, it should not be construed as a limitation to the embodiments of the present application.

[0054] Unless otherwise clearly specified or limited, in the description of the embodiments of the present application, the terms "installed", "connected", "connected", "fixed", "set", etc. used should be understood in a broad sense. For example, the "connection" can be a fixed connection, a detachable connection, or an integral setting; it can be a mechanical connection, an electrical connection, or a communication connection; it can be directly connected, or indirectly connected through an intermediate medium; it can be the communication inside two components or the interaction relationship between two components. For those skilled in the technical field to which the present application belongs, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0055] Please refer to Figure 1 , a power outage cause detection circuit for an outdoor distribution box in this embodiment, includes:

[0056] A mains voltage detection circuit 110, the mains voltage detection circuit 110 is arranged at the load end of the transformer of the outdoor distribution box, and the mains voltage detection circuit 110 is used to detect whether the load equipment of the outdoor distribution box loses power;

[0057] An air switch state detection circuit 120, the air switch state detection circuit 120 is arranged at the load end of the transformer of the outdoor distribution box, and the air switch state detection circuit 120 is used to detect the state of the air switch at the load end of the transformer;

[0058] A main control module 130, the main control module 130 is connected to the mains voltage detection circuit 110 and the air switch state detection circuit 120. When it is detected by the mains voltage detection circuit 110 that the load equipment of the outdoor distribution box loses power, the main control module 130 is used to detect the state of the air switch at the load end of the transformer through the air switch state detection circuit 120, and send the detected result to the upper computer;

[0059] A communication circuit 140, the communication circuit 140 is connected to the main control module 130, and the communication circuit 140 is used for information interaction between the main control module 130 and the upper computer;

[0060] A power supply circuit 150, the power supply circuit 150 is connected to the air switch state detection circuit 120 and the main control module 130, and the power supply circuit 150 is used to supply power to the air switch state detection circuit 120 and the main control module 130.

[0061] It is connected through the power supply circuit 150 to supply power to the air switch state detection circuit 120 and the main control module 130. The main control module 130 detects whether the load device of the outdoor distribution box is powered off through the mains voltage detection circuit 110 arranged at the load end of the transformer of the outdoor distribution box. If it is detected that the load device of the outdoor distribution box is powered off, the air switch state detection circuit 120 arranged at the load end of the transformer of the outdoor distribution box is started to detect the state of the air switch at the load end of the transformer, and then the detection result is sent to the upper computer through the communication circuit 140, so that when the load device of the outdoor distribution box is powered off, the maintenance personnel can know in time through the upper computer that the corresponding outdoor distribution box is powered off. By judging according to the air switch, the reason for the power outage of the distribution box can be determined, so that the maintenance personnel can formulate corresponding maintenance plans in time and then go to the site for maintenance, improving the maintenance efficiency of the maintenance personnel.

[0062] Please refer to Figure 2 , in some embodiments, the mains voltage detection circuit 110 includes a first voltage dividing resistor R2 and a second voltage dividing resistor R3;

[0063] One end of the first voltage dividing resistor R2 is connected to one end of the load device, the other end of the first voltage dividing resistor R2 is connected to the main control unit and one end of the second voltage dividing resistor R3, and the other end of the second voltage dividing resistor R3 is grounded.

[0064] Among them, a voltage dividing circuit is formed by the first voltage dividing resistor R2 and the second voltage dividing resistor R3, and the voltage value at one end of the load device is collected through the voltage dividing circuit to detect the mains voltage of the outdoor distribution box, and then it is judged whether the load device of the outdoor distribution box is powered off.

[0065] In some embodiments, the air switch state detection circuit 120 includes a switching element Q1, a third resistor R5, a fourth resistor R6 and a fifth resistor R7;

[0066] One end of the switching element Q1 is connected to the power supply circuit 150, the other end of the switching element Q1 is connected to one end of the third resistor R5, and the control end of the switching element Q1 is connected to the main control module 130;

[0067] The other end of the third resistor R5 is connected to one end of the load device;

[0068] One end of the fourth resistor R6 is connected to the other end of the load device, and the other end of the fourth resistor R6 is grounded;

[0069] One end of the fifth resistor R7 is connected to the other end of the load device, and the other end of the fifth resistor R7 is connected to the main control module 130;

[0070] The main control module 130 is further configured to, when the load device loses power, calculate the impedance of the load device loop according to the voltage value fed back by the fifth resistor R7 by controlling the switch element Q1 to be turned on, and determine the state of the air switch at the load end of the transformer according to the calculated impedance.

[0071] After the distribution box loses power, the closing state or the opening state of the air switch will affect the impedance of the load device loop. When the air switch is in the closing state, the load device is connected to the secondary of the load end of the transformer, and when the air switch is in the opening state, the load device is disconnected from the secondary of the load end of the transformer. By collecting the voltage value fed back by the fifth resistor R7, the impedance of the load device loop can be calculated, and then the state of the air switch can be determined according to the calculated impedance.

[0072] Specifically, when the load device loses power, the main control module 130 is further configured to, after controlling the switch element Q1 to be turned on, delay for a preset time, collect the DC voltage value fed back by the fifth resistor R7, and calculate the DC impedance R of the load device loop according to the DC voltage value L ; and control the switch element Q1 to be intermittently turned on at a first preset frequency, where the first preset frequency is 50 Hz, collect the first AC voltage value fed back by the five resistors R7, and calculate the first AC impedance X of the load device loop according to the first AC voltage value L50hz Control the switch element Q1 to be intermittently turned on at a second preset frequency, where the second preset frequency is 1 KHz, collect the second AC voltage value fed back by the five resistors R7, and calculate the second AC impedance X of the load device loop according to the second AC voltage value L1Khz Judge the state of the air switch at the load end of the transformer according to the calculated DC impedance, first AC impedance and second AC impedance.

[0073] When the air switches SW1 and SW2 are closed, since the secondary inductance of the mains distribution transformer T1 has a relatively steep slope as the signal frequency gradually increases at a relatively high frequency;

[0074] When the air switch SW1 or the air switch SW2 is opened, the secondary of the mains distribution transformer T1 will not be connected in parallel to the load device, and the DC impedance R of the load device loop L only includes the load DC impedance, and its value is relatively large. Since the secondary inductance of the mains distribution transformer T1 is not connected in parallel to the load device loop, the slope of the load device loop as the signal frequency gradually increases will slow down, and there is X L50hzMuch less than X L1Khz 。

[0075] In some embodiments, the switching element Q1 is a MOS transistor. MOS is the abbreviation of MOSFET. MOSFET stands for Metal-Oxide-Semiconductor Field-Effect Transistor, also known as Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET). Field-effect transistors are divided into PMOS transistors (P-channel type) and NMOS (N-channel type) transistors, belonging to insulated-gate field-effect transistors. In this embodiment, an NMOS transistor is used. The MOS transistor is turned on by outputting a low level to it and turned off by outputting a high level. In other embodiments, other components such as a triode, a switching transistor, an IGBT transistor, etc. can also be used as the switching element Q1.

[0076] Please refer to Figure 2 , in some embodiments, it further includes a supercapacitor backup power circuit 160. The supercapacitor backup power circuit 160 includes a supercapacitor C1 and a diode D1. One end of the supercapacitor C1 is connected to the cathode of the diode D1 and the power input terminal of the main control module 130. The other end of the supercapacitor C1 is grounded. The anode of the diode D1 is connected to the power supply circuit 150.

[0077] By setting the supercapacitor C1 at the power input terminal of the main control module 130, when the power supply circuit 150 is powered off, the main control module 130 can continue to be powered by the discharge of the supercapacitor for a period of time.

[0078] In some embodiments, it further includes a zero-sequence current transformer 170,

[0079] The zero-sequence current transformer 170 is arranged at the load end of the transformer of the outdoor distribution box. The zero-sequence current transformer 170 is connected to the main control module 130. The zero-sequence current transformer 170 is used to detect the leakage current of the load device.

[0080] The main control module 130 can detect the leakage current of the load device through the zero-sequence current transformer 170. When the leakage current of the load device is too large, a leakage flag is set and sent to the host computer.

[0081] In some embodiments, it further includes a current transformer 180. The current transformer 180 is arranged at the load end of the transformer of the outdoor distribution box. The current transformer 180 is connected to the main control module 130. The current transformer 180 is used to detect the working current of the load device.

[0082] The working current of the load device is detected through the current transformer 180. If the load device is overcurrent, an overload flag is set and sent to the host computer.

[0083] In some embodiments, an indicator light 190 is further included, and the indicator light 190 is connected to the main control module 130. The indicator light 190 is used to indicate the operating state of the main control module.

[0084] In some embodiments, the main control module 130 is a main control single-chip microcomputer. A single-chip microcomputer is an integrated circuit chip. It uses very large scale integrated circuit technology to integrate a central processing unit CPU with data processing capabilities, a random access memory RAM, a read-only memory ROM, multiple I / O ports, an interrupt system, a timer / counter and other functions (which may also include a display driver circuit, a pulse width modulation circuit, an analog multiplexer, an A / D converter and other circuits) onto a silicon chip to form a small and complete microcomputer system, which is widely used in the field of industrial control. It is small in size, light in weight, cheap in price, and provides convenient conditions for learning, application and development.

[0085] In some embodiments, a detection circuit for the power outage reason of an outdoor distribution box, the system composition block diagram of which is as Figure 1 shown. It is composed of a power supply circuit 150, a super capacitor backup power supply circuit 160, a zero-sequence current transformer 170, a current transformer 180, a breaker state detection circuit 120, a mains voltage detection circuit 110, a main control single-chip microcomputer, a communication circuit 140, an indicator light 190 and a load device.

[0086] The power supply circuit 150 supplies power to the detection circuit and charges the super capacitor backup power supply circuit 160; the super capacitor backup power supply circuit 160 continuously supplies power to the detection circuit for the power outage reason of the outdoor distribution box for a period of time during a power outage; the zero-sequence current transformer 170 is used to detect the leakage current of the outdoor distribution box; the current transformer 180 is used to detect the working current of the load device; the mains voltage detection circuit 110 is used to detect the mains voltage of the outdoor distribution box and is used to detect the power outage information of the load device; the breaker state detection circuit 120 works instantaneously during a power outage and is used to detect whether the state of the breaker is open or closed; the communication circuit 140 is used to upload data to the upper computer.

[0087] The detection circuit for the power outage reason of the outdoor distribution box is as Figure 2 shown, U1 is the main control single-chip microcomputer, T1 is the mains distribution transformer, SW1 and SW2 are the air switches in the outdoor distribution box, T2 is the zero-sequence current transformer 170, and the resistor R1 is used to detect the leakage current of the load device. T3 is the current transformer 180, and the resistor R4 is used to detect the working current of the load device, RL is the load device, P1 is the interface for connecting the communication circuit 140, and LED1 is the indicator light 190.

[0088] The voltage dividing circuit composed of R2 and R3 is the mains voltage detection circuit 110.

[0089] The system determines the DC impedance R of the load device loop L , the AC impedance X L50hz and the AC impedance X L1Khz to obtain whether the air switches (SW1, SW2) are in the open or closed state.

[0090] When the air switches are open, the open switch state detection circuit 120 is composed of the switching element Q1, the third resistor R5, RL, and the fourth resistor R6, and the loop equivalent circuit is as Figure 3 shown. Since RL is generally a capacitive load, the DC impedance of the entire loop is large.

[0091] When the air switches are closed, the open switch state detection circuit 120 is composed of Q1, R5, RL, the mains power distribution transformer, and R6, and the loop equivalent circuit is as Figure 4 shown. The mains power distribution transformer is in parallel with RL. Due to the effect of the mains power distribution transformer, the DC impedance of the entire loop is small.

[0092] Combining data such as the leakage current of the outdoor distribution box, the working current of the load device, the mains voltage, and the open switch state, the reasons for power outage are classified into reasons such as abnormal external mains input (mains power outage and open switch closed), distribution box leakage (open switch open), load device overload (open switch open), etc., and are uploaded to the upper computer through the communication circuit 140.

[0093] Please refer to Figure 5 , the method for detecting the reasons for power outage of the outdoor distribution box;

[0094] The program of the entire detection method is executed in the main control single-chip microcomputer:

[0095] Output a high level on DO1 of the main control single-chip microcomputer, turn off the switching element Q1, and the open switch state detection circuit 120 pauses working;

[0096] Detect the leakage current of the load device through the zero-sequence current transformer 170, and set the leakage flag if the leakage current is too large;

[0097] Detect the working current of the load device through the current transformer 180, and set the overload flag if overcurrent occurs;

[0098] Detect the mains voltage of the load device through the mains voltage detection circuit 110;

[0099] Judge the mains voltage value to identify whether the load device of the distribution box has lost power;

[0100] When it is detected that the load device has lost power, output a low level on DO1, turn on the switching element Q1, and after a certain time delay, collect the DC voltage value of AD3, and the DC impedance RL of the load device loop can be obtained through calculation;

[0101] DO1 outputs a signal with a frequency of 50 Hz, intermittently turns on the switching element Q1, acquires the first AC voltage value of AD3, and obtains the first AC impedance X of the load device circuit at 50 Hz through calculation L50hz ;

[0102] DO1 outputs a signal with a frequency of 1 kHz, intermittently turns on the switching element Q1, acquires the second AC voltage value of AD3, and obtains the second AC impedance X of the load device circuit at 1 kHz through calculation L1Khz ;

[0103] Judge the DC impedance RL and AC impedance X of the load device circuit L50hz and the AC impedance X L1Khz Obtain whether the air switches (SW1, SW2) are in the open or closed state.

[0104] When the air switches SW1 and SW2 are closed, due to the secondary inductance of the mains distribution transformer T1, when the frequency is relatively high, the slope that gradually increases with the signal frequency is relatively steep;

[0105] When the air switch SW1 or the air switch SW2 is open, the secondary of the mains distribution transformer will not be connected in parallel to the load device, and the DC impedance R of the load device circuit L only includes the load DC impedance, and its value is relatively large. Since the secondary inductance of the mains distribution transformer T1 is not connected in parallel to the load device circuit, the slope that gradually increases with the signal frequency will slow down, and there is X L50hz is much smaller than X L1Khz ;

[0106] Combining data such as the leakage current of the outdoor distribution box, the working current of the load device, the mains voltage, and the breaker status, classify the power outage reasons into reasons such as abnormal external mains input (mains power outage and breaker closed), distribution box leakage (breaker open), load device overload (breaker open), etc., and upload them to the upper computer through the communication circuit 140.

[0107] Finally, it should be noted that although the above embodiments have been described in the text and drawings of the specification of this application, the patent protection scope of this application cannot be limited thereby. Any technical solution obtained by equivalent structure or equivalent process substitution or modification based on the essential concept of this application and using the content recorded in the text and drawings of the specification of this application, as well as directly or indirectly implementing the technical solutions of the above embodiments in other related technical fields, etc., are all included in the patent protection scope of this application.

Claims

1. An outdoor distribution box power outage cause detection circuit, characterized in that, Including: Mains voltage detection circuit, which is arranged at the load end of the transformer of the outdoor distribution box, and is used to detect whether the load device of the outdoor distribution box loses power; Circuit breaker state detection circuit, which is arranged at the load end of the transformer of the outdoor distribution box, and is used to detect the state of the air switch at the load end of the transformer; Main control module, which is connected to the mains voltage detection circuit and the circuit breaker state detection circuit. The main control module is used to detect the state of the air switch at the load end of the transformer through the circuit breaker state detection circuit when it is detected by the mains voltage detection circuit that the load device of the outdoor distribution box loses power, and send the detected result to the host computer; Communication circuit, which is connected to the main control module, and is used for information interaction between the main control module and the host computer; Power supply circuit, which is connected to the circuit breaker state detection circuit and the main control module, and is used to supply power to the circuit breaker state detection circuit and the main control module.

2. The outdoor power distribution box power outage cause detection circuit according to claim 1, characterized in that, The mains voltage detection circuit includes a first voltage-dividing resistor and a second voltage-dividing resistor; One end of the first voltage-dividing resistor is connected to one end of the load device, the other end of the first voltage-dividing resistor is connected to the main control unit and one end of the second voltage-dividing resistor, and the other end of the second voltage-dividing resistor is grounded.

3. The outdoor power distribution box power outage cause detection circuit according to claim 1, characterized in that The circuit breaker state detection circuit includes a switching element, a third resistor, a fourth resistor and a fifth resistor; One end of the switching element is connected to the power supply circuit, the other end of the switching element is connected to one end of the third resistor, and the control end of the switching element is connected to the main control module; The other end of the third resistor is connected to one end of the load device; One end of the fourth resistor is connected to the other end of the load device, and the other end of the fourth resistor is grounded; One end of the fifth resistor is connected to the other end of the load device, and the other end of the fifth resistor is connected to the main control module; The main control module is also used to calculate the impedance of the load device loop according to the voltage value fed back by the fifth resistor by controlling the switching element to turn on when the load device loses power, and judge the state of the air switch at the load end of the transformer according to the calculated impedance.

4. The outdoor distribution box power outage cause detection circuit according to claim 3, characterized in that, The main control module is also used to collect the DC voltage value fed back by the fifth resistor after a preset time delay after controlling the switching element to turn on when the load device loses power, and calculate the DC impedance of the load device loop according to the DC voltage value; and control the switching element to intermittently turn on at a first preset frequency, collect the first AC voltage value fed back by the fifth resistor, calculate the first AC impedance of the load device loop according to the first AC voltage value, control the switching element to intermittently turn on at a second preset frequency, collect the second AC voltage value fed back by the fifth resistor, calculate the second AC impedance of the load device loop according to the second AC voltage value, and judge the state of the air switch at the load end of the transformer according to the calculated DC impedance, first AC impedance and second AC impedance.

5. The outdoor power distribution box power outage cause detection circuit according to claim 3, characterized in that, The switching element is a MOS tube.

6. The outdoor distribution box power outage cause detection circuit according to claim 1, characterized in that It further includes a super capacitor and a diode. One end of the super capacitor is connected to the cathode of the diode and the power input terminal of the main control module. The other end of the super capacitor is grounded. The anode of the diode is connected to the power supply circuit.

7. The power outage cause detection circuit of the outdoor distribution box according to claim 1, characterized in that It further includes a zero-sequence current transformer. The zero-sequence current transformer is arranged at the load end of the transformer of the outdoor distribution box. The zero-sequence current transformer is connected to the main control module and is used for detecting the leakage current of the load device.

8. The power outage cause detection circuit for the outdoor distribution box according to claim 1, characterized in that, It further includes a current transformer. The current transformer is arranged at the load end of the transformer of the outdoor distribution box. The current transformer is connected to the main control module and is used for detecting the working current of the load device.

9. The outdoor distribution box power outage cause detection circuit according to claim 1, characterized in that It further includes an indicator light, and the indicator light is connected to the main control module.

10. The outdoor distribution box power outage cause detection circuit according to claim 1, wherein, The main control module is a main control single-chip microcomputer.

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