Integrated current sensor

Abstract

An integrated current sensor belongs to the technical field of current sensors. Comprising a shell (1) and a threading hole (2), a residual current magnetic core (11) and a Hall sensor (9) are arranged in the shell (1), a control circuit is arranged in the shell (1), a residual current induction coil and the Hall sensor (9) are respectively connected into the control circuit, the control circuit comprises a microprocessor, the output end of the Hall sensor (9) is connected with the microprocessor, and the output end of the Hall sensor (9) is connected with the microprocessor. The residual current induction coil is connected with the direct current sampling module or the alternating current sampling module through the change-over switch, and the output end of the direct current sampling module or the alternating current sampling module is connected with the microprocessor. According to the integrated current sensor, identification of a direct current system and an alternating current system is achieved, switching is achieved through the change-over switch, and load current measurement and residual current measurement can be achieved at the same time whether the integrated current sensor is applied to the direct current system or the alternating current system.

Description

Technical Field

[0001] The invention discloses an integrated current sensor, belonging to the technical field of current sensors. Background Art

[0002] In power supply systems, real-time monitoring of residual current and load current in each load circuit is required. In DC power supply systems, residual current is typically detected using a DC residual current sensor, which measures the differential current between the positive and negative cables. This current is typically small, in the microampere range; the load current is typically in the ampere range, and load current detection is typically achieved using a shunt or Hall-effect current sensor. Shunts connected in series with cables can easily overheat and require disconnecting the primary cable, posing a safety hazard. Hall-effect current sensors isolate and measure load current, offering high safety and widespread use, but they cannot detect minute residual currents. In AC power supply systems, load and residual currents are typically measured using transformers. This is conventional technology and will not be discussed here. Currently, separate measurement sensors are used in DC and AC systems, with separate sensors for residual current and load current. This excessive number of sensors results in large space requirements and high costs.

[0003] The Chinese utility model patent with application number 202321619859.1 and application date June 26, 2023, and the patent name “A combined transformer” discloses a technical solution in which the current transformer and the leakage current transformer are placed in the same housing, thereby realizing the simultaneous detection of the system load current and the leakage current (residual current). However, in this technical solution, no distinction is made between DC systems and AC systems, so the load current and leakage current can only be detected simultaneously for DC systems or AC systems. Therefore, designing a technical solution that can meet the current detection requirements of both DC systems and AC systems (either one) to improve applicability has become an urgent problem to be solved in this field. Utility Model Content

[0004] The technical problem to be solved by the utility model is: to overcome the shortcomings of the existing technology and provide an integrated current sensor that can realize the identification of DC system and AC system and realize switching by switching, and can simultaneously realize load current and residual current measurement regardless of being applied in DC system or AC system.

[0005] The technical solution adopted by the utility model to solve its technical problems is: the integrated current sensor includes a shell, a wire threading hole is set through the surface of the shell, a residual current core and a Hall sensor are set in the shell, a residual current induction coil is wound on the residual current core, a control circuit is set in the shell, the residual current induction coil and the Hall sensor are respectively connected to the control circuit, and is characterized in that: the control circuit includes a microprocessor, the output end of the Hall sensor is connected to the microprocessor, the residual current induction coil is connected to the DC sampling module or the AC sampling module through a switching switch, and the output end of the DC sampling module or the AC sampling module is connected to the microprocessor.

[0006] Preferably, two wire-through holes are provided, and the neutral wire and the live wire of the AC circuit pass through the two wire-through holes respectively, or the positive line and the negative line of the DC circuit pass through the two wire-through holes respectively.

[0007] Preferably, an isolation sleeve is provided through the surface of the outer shell, and the threading hole is located at the center of the isolation sleeve.

[0008] Preferably, the isolation sleeve comprises an inner sleeve and an outer sleeve, which are respectively inserted from the front end face and the rear end face of the outer shell and are integrated into the inner part of the outer shell.

[0009] Preferably, the two threading holes are respectively located on the inner ring of the residual current core, and the Hall sensor is arranged outside one of the isolation sleeves.

[0010] Preferably, a magnetic focusing ring is provided on the outside of one of the isolation sleeves, an opening is provided on the surface of the magnetic focusing ring, and the Hall sensor is located in the opening of the magnetic focusing ring.

[0011] Preferably, a shielding shell is provided inside the outer shell, and the residual current magnetic core and the Hall sensor are located inside the shielding shell.

[0012] Preferably, a bottom cover is provided at the lower port of the housing, a circuit board is provided on the surface of the bottom cover, the control circuit is provided on the circuit board, and wiring terminals are provided on the circuit board, and the wiring terminals are connected to the control circuit.

[0013] Preferably, the output end of the microprocessor is connected to the control end of the switch.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] In this integrated current sensor, the DC system and the AC system are identified and switched by a switch. Regardless of whether it is applied in a DC system or an AC system, the load current and the residual current can be measured simultaneously.

[0016] In this integrated current sensor, the load current and residual current are measured through a single shell, avoiding the current problem in DC systems and AC systems where different measurement sensors are needed for the residual current and the load current, respectively. Excessive sensors lead to large space occupation and high costs.

[0017] Two penetrating isolation sleeves are arranged side by side on the surface of the shell. The centers of the two isolation sleeves are threading holes. The isolation sleeves not only play the role of electromagnetic isolation, but also play the role of shielding the opening of the shell.

[0018] The isolation sleeve, the residual current magnetic core, the magnetic focusing ring and the Hall sensor are all located in the shielding shell, which plays a shielding role to prevent the current sensor from being interfered with externally during operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is the axonometric view of the integrated current sensor.

[0020] Figure 2 This is the front view of the integrated current sensor.

[0021] Figure 3 This is the left view of the integrated current sensor.

[0022] Figure 4 This is the exploded diagram of the integrated current sensor.

[0023] Figure 5 for Figure 3 Middle AA section view.

[0024] Figure 6 This is the principle block diagram of the integrated current sensor control circuit.

[0025] Among them: 1, shell 2, threading hole 3, isolation sleeve 4, terminal 5, bottom cover 6, outer sleeve 7, inner sleeve 8, magnetic ring 9, Hall sensor 10, shielding shell 11, residual current core 12, circuit board. DETAILED DESCRIPTION

[0026] Figures 1 to 6 This is the best embodiment of the present invention, Figures 1 to 6 The utility model is further described.

[0027] like Figures 1-3 As shown, the integrated current sensor (hereinafter referred to as the current sensor) includes a housing 1 with an open bottom. A bottom cover 5 is provided at the bottom opening of the housing 1 to seal the bottom opening. Terminals 4 are provided at the lower portion of the front end of the housing 1 to output the collected data of the current sensor.

[0028] Two penetrating isolation sleeves 3 are arranged side by side on the surface of the housing 1 . The centers of the two isolation sleeves 3 are wire holes 2 . The isolation sleeves 3 not only play the role of electromagnetic isolation, but also play the role of shielding the opening of the housing 1 .

[0029] Combine Figures 4 and 5 A residual current core 11 is disposed within the housing 1, with two threading holes 2 located within the inner ring of the residual current core 11. The isolation sleeve 3 is a split structure, consisting of an inner sleeve 7 and an outer sleeve 6, which are nested within the housing. The inner sleeve 7 and outer sleeve 6 are inserted from the front and rear ends of the housing 1, respectively, and are nested within the housing 1 as a single unit.

[0030] Inside the housing 1, a magnetic focusing ring 8 is provided. The magnetic focusing ring 8 is a ring-shaped metal structure and is sleeved on the outside of one of the isolation sleeves 3. A notch is provided on the surface of the magnetic focusing ring 8, and a Hall sensor 9 is provided in the notch. The Hall sensor 9 and the magnetic focusing ring 8 are combined to form an open-loop Hall current sensor.

[0031] A shielding shell 10 is also provided in the outer shell 1. The shielding shell 10 consists of two independent shielding monomers, which are connected front and back in the outer shell 1 to form a whole. The above-mentioned isolation sleeve 3, residual current core 11, magnetic focusing ring 8 and Hall sensor are all located in the shielding shell 10. The shielding shell 10 plays a shielding role to prevent the current sensor from being interfered with externally during operation.

[0032] A circuit board 12 is provided on the upper surface of the bottom cover 6. The control circuit of the current sensor is mounted on this circuit board 12. The aforementioned terminal blocks 4 are fixed to the surface of and connected to the circuit board 12. The signal output of the Hall effect sensor 9 is connected to the control circuit on the circuit board 12. A residual current induction coil (not shown) for sensing residual current is wound around the surface of the residual current core 11. The output of the induction coil is also connected to the control circuit.

[0033] like Figure 6 As shown, the control circuit provided on circuit board 12 includes an amplifier module connected to the output of Hall sensor 9. The output of the amplifier module is connected to the input of a sampling module, which in turn is connected to the input of a microprocessor. Both the amplifier module and the sampling module are implemented using amplifier circuits and sampling circuits (or chips) commonly used in the art and will not be described in detail here.

[0034] The output of the residual current sensing coil is connected to the input of a switch. The switch can be implemented using a relay or analog switch. The two sets of contacts of the switch are connected to the DC sampling module and the AC sampling module, respectively. The DC sampling module and the AC sampling module are also connected to the signal input of the microprocessor, and the signal output of the microprocessor is connected to the control terminal of the switch. At the same time, the communication interface of the microprocessor is connected to the communication module, and the port of the communication module is connected to the terminal 4 to enable the uploading of current data and the issuance of control commands. Therefore, the microprocessor can also be controlled by the host computer to realize the operation of the switch.

[0035] The specific working process and working principle are as follows:

[0036] When the current sensor is applied to a DC system, the positive and negative wires of the DC circuit pass through the two wire holes 2 respectively; when the current sensor is applied to an AC system, the live and neutral wires of the AC system pass through the two wire holes 2 respectively.

[0037] The Hall effect sensor 9 collects the load current of the DC or AC system during operation and outputs the signal. The signal output by the Hall effect sensor 9 is sent to the microprocessor through the amplification module and sampling module. The microprocessor calculates the data collected by the Hall effect sensor 9 and obtains the load current at the line terminal.

[0038] The microprocessor simultaneously determines whether the current system is a DC or AC system based on data input from Hall effect sensor 9. Using Hall effect sensor 9 to determine whether the system is a DC or AC system is common knowledge in the art (see the technical solution described in Chinese invention patent application number 201510570301.2, filed on September 9, 2015, entitled "AC / DC High Voltage Electrical Testing Device") and will not be further elaborated here.

[0039] After determining whether the current system is a DC system or an AC system, the microprocessor sends a control signal to the switch to switch to the DC sampling module or the AC sampling module for operation.

[0040] When the microprocessor controls the switch to connect the residual current sensing coil and the DC sampling module, the DC sampling module sends a DC excitation signal to the coil. An oscillation signal is generated on the residual current sensing coil. When a DC leakage current passes through the wire hole 2 of the coil, the oscillation signal changes. By detecting the change in the oscillation signal, the magnitude of the DC leakage current can be calculated. This sampling scheme is described in detail in the patent applied for by our company and will not be repeated here (see the technical solution described in the Chinese invention patent with application number 202111049369.8, application date September 8, 2021, and patent name "A Multi-bit Current Sensor").

[0041] When the microprocessor controls the switch to connect the residual current sensing coil and the AC sampling module, the residual current sensing coil and the AC sampling module form an AC sampling system. According to the principle of electromagnetic induction, the current passing through the sensing coil * the number of turns of the cable passing through the induction coil threading hole 2 = the number of turns of the induction coil * the current in the induction coil. Therefore, I1N1 = I2N2. Where N1 is the number of turns of the primary cable passing through the induction coil, which is 1 turn; I1 is the residual current being measured; N2 is the number of turns of the residual current sensing coil; and I2 is the current in the induction coil. By measuring I2, the magnitude of the measured residual current I1 can be calculated.

[0042] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation thereto. Any person skilled in the art may utilize the above disclosure to modify or remodel the present invention into equivalent embodiments. However, any simple modification, equivalent variation, or modification of the above embodiment that does not depart from the technical content of the present invention and is based on the technical essence of the present invention shall still fall within the scope of protection of the present invention.

Claims

1. An integrated current sensor, comprising a housing (1), a wire threading hole (2) penetrating the surface of the housing (1), a residual current core (11) and a Hall sensor (9) disposed within the housing (1), a residual current induction coil wound around the residual current core (11), a control circuit disposed within the housing (1), the residual current induction coil and the Hall sensor (9) being connected to the control circuit respectively, characterized in that: The control circuit includes a microprocessor, the output end of the Hall sensor (9) is connected to the microprocessor, the residual current induction coil is connected to the DC sampling module or the AC sampling module via a switch, and the output end of the DC sampling module or the AC sampling module is connected to the microprocessor.

2. The integrated current sensor according to claim 1, characterized in that: Two wire-through holes (2) are provided, and the neutral line and the live line of the AC circuit pass through the two wire-through holes (2) respectively, or the positive line and the negative line of the DC circuit pass through the two wire-through holes (2) respectively.

3. The integrated current sensor according to claim 1 or 2, characterized in that: An isolation sleeve (3) is provided through the surface of the housing (1), and the threading hole (2) is located at the center of the isolation sleeve (3).

4. The integrated current sensor according to claim 3, characterized in that: The isolation sleeve (3) comprises an inner sleeve (7) and an outer sleeve (6). The inner sleeve (7) and the outer sleeve (6) are respectively inserted from the front end face and the rear end face of the outer shell (1) and are integrated into the inner shell (1).

5. The integrated current sensor according to claim 3, characterized in that: The two threading holes (2) are respectively located on the inner ring of the residual current magnetic core (11), and the Hall sensor (9) is arranged outside one of the isolation sleeves (3).

6. The integrated current sensor according to claim 5, characterized in that: A magnetic focusing ring (8) is provided on the outside of one of the isolation sleeves (3), an opening is provided on the surface of the magnetic focusing ring (8), and a Hall sensor (9) is located in the opening of the magnetic focusing ring (8).

7. The integrated current sensor according to claim 1, characterized in that: A shielding shell (10) is provided in the housing (1), and the residual current magnetic core (11) and the Hall sensor (9) are located in the shielding shell (10).

8. The integrated current sensor according to claim 1, characterized in that: A bottom cover (5) is provided at the lower end of the housing (1), a circuit board (12) is provided on the surface of the bottom cover (5), a control circuit is provided on the circuit board (12), a wiring terminal (4) is provided on the circuit board (12), and the wiring terminal (4) is connected to the control circuit.

9. The integrated current sensor according to claim 1, characterized in that: The output end of the microprocessor is connected to the control end of the switch.

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