Intelligent mutual inductor

Abstract

The utility model is suitable for the technical field of low-voltage power distribution monitoring, and relates to an intelligent mutual inductor, which comprises a voltage measurement module, a microcontroller module, a power supply module and a power supply module, the temperature measurement module is used for measuring the temperature by measuring the partial voltage change generated by the change of the thermistor; the power supply module is used for supplying power to each module of the intelligent mutual inductor; the microcontroller module is used for calculating and correcting a voltage measurement value, calculating and correcting a temperature measurement value and processing a transceiving command of the 485 communication module; the 485 communication module is used for receiving and transmitting communication with the microcontroller module; and the current output control module is used for reducing the current value of the parallel circuit through the short circuit of the current transformer output line. The device is high in integration level, low in cost, capable of being installed without power failure, and high in safety performance.

Description

Technical Field

[0001] The utility model belongs to the technical field of low - voltage power distribution monitoring, and particularly relates to an intelligent mutual inductor. Background Technique

[0002] In the power energy monitoring system of a low - voltage power distribution room, it is crucial to accurately detect the electrical parameters of the incoming main circuit and multiple feeder branch circuits. Usually, there is a one - to - many (1:N) relationship between the incoming main circuit and the feeder branch circuits, that is, one incoming main circuit corresponds to multiple feeder branch circuits.

[0003] In traditional monitoring schemes, as Figure 2 shown, the common practice is to install independent power monitoring instruments in each branch circuit to achieve real - time monitoring of power energy parameters. These monitoring instruments have various functions and need to obtain necessary voltage, current, and temperature signals through external access. Specifically, the access of voltage signals usually adopts a direct wiring method, that is, cables are led out from the terminals of the upstream molded - case circuit breaker and connected to the monitoring instruments; the acquisition of current signals mostly relies on current transformers (CTs) to convert large currents into small current signals suitable for the monitoring instruments to collect; as for temperature signals, temperature sensors are installed on relevant cables, and the sensors are connected to the monitoring instruments through the cables to achieve the acquisition of temperature data. However, this sensing - based monitoring mode has certain limitations: First, it usually requires power outage for construction, which may affect the normal operation of the power system; second, due to the need to install multiple monitoring instruments and lay a large number of cables, the complexity of wiring and the construction difficulty are relatively high, and the safety is low; in addition, the cost of the monitoring instruments and their supporting sensors is also considerable, which may increase the investment cost of the entire monitoring system.

[0004] Therefore, how to provide a mutual inductor with lower cost, simple and reliable installation, and capable of being installed without power outage is an urgent problem to be solved by those skilled in the art. Content of the Utility Model

[0005] Aiming at the deficiencies of the prior art, the purpose of the utility model is to provide an intelligent mutual inductor to solve the problems of high cost and low safety performance of the monitoring devices in the prior art.

[0006] To solve the above - mentioned technical problems, the utility model adopts the following technical solutions:

[0007] The utility model provides an intelligent mutual inductor, including:

[0008] A voltage measurement module is used to measure the voltage on the line to be measured and amplify the voltage to the signal range that can be sampled by the microcontroller module; a temperature measurement module is used to measure the temperature by measuring the change in the partial voltage generated by the change of the thermistor; a power supply module is used to supply power to each module of the intelligent transformer; a microcontroller module is used for voltage measurement value calculation and correction, temperature measurement value calculation and correction, and transceiver command processing of the 485 communication module; a 485 communication module is used for transceiver communication with the microcontroller module; a current output control module is used to reduce the current value of the parallel circuit by short-circuiting the output line of the current transformer; the voltage measurement module, temperature measurement module, power supply module, 485 communication module, and current output control module are respectively communicatively connected to the microcontroller module.

[0009] Further, the voltage measurement module includes a voltage sensor and a voltage measurement circuit. The voltage sensor includes a voltage induction copper sheet and a coupling sampling capacitor. The voltage measurement circuit includes a two-stage amplifier and a data processor. The voltage induction copper sheet, coupling sampling capacitor, two-stage amplifier, and data processor are connected in sequence.

[0010] Further, the temperature measurement module includes a temperature sensor and a temperature measurement circuit. The temperature sensor includes a temperature induction resistor. The temperature measurement circuit includes a voltage division sampling resistor and a data processor. The temperature induction resistor, voltage division sampling resistor, and data processor are connected in sequence.

[0011] Further, the power supply module includes an external input 12V power supply for powering the microcontroller module, a DC / DC voltage conversion circuit for powering the 485 communication circuit, and a charge pump circuit for powering the voltage measurement circuit.

[0012] Further, the current output control module includes a current control switch and a sampling resistor for the backend device circuit. The current control switch, the sampling resistor for the backend device resistor, and the current transformer are connected in parallel.

[0013] Further, it further includes an indicator light module for displaying the working state of the intelligent transformer. The indicator light module is communicatively connected to the microcontroller module.

[0014] Further, it further includes a first upper housing, a second upper housing, a fixed part for the upper and lower housings of the mutual inductor, a first lower housing, a second lower housing, a printed circuit board, a first current core and a second current core. The first upper housing is connected to the second upper housing. The fixed part for the upper and lower housings of the mutual inductor is arranged on the outer side of the overall connection of the first upper housing and the second upper housing. The first current core is arranged on the inner side of the overall connection of the first upper housing and the second upper housing. The first lower housing is connected to the second lower housing. The second current core, the voltage induction copper sheet, the temperature induction resistor and the printed circuit board are all arranged on the inner side of the overall connection of the first lower housing and the second lower housing.

[0015] Further, it further includes a cable fixing part, and the cable fixing part is installed on the lower half of the intelligent mutual inductor on the overall connection of the first lower housing and the second lower housing.

[0016] Further, the voltage induction copper sheet is provided with a positive pole of the voltage induction copper sheet, a negative pole of the voltage induction copper sheet, a through hole for the temperature induction resistor and a coaxial transmission cable interface.

[0017] Compared with the prior art, the intelligent mutual inductor provided by the present utility model has at least the following beneficial effects:

[0018] In the prior art, construction usually needs to be carried out with power cut, which will affect the normal operation of the power system. Secondly, due to the need to install multiple monitoring instruments and lay a large number of cables, the complexity of cable routing and the construction difficulty are relatively high, and the safety is relatively low. In addition, the cost of the monitoring instruments and their supporting sensors is also considerable, which may increase the investment cost of the entire monitoring system. The structure of the present utility model is simple and easy to install. The intelligent mutual inductor integrates voltage measurement, current measurement and temperature measurement, and has a high integration degree. The mutual inductor is directly clamped on the cable without redundant cables and has a low cost. The present utility model is of an open type installation, without the need for power cut, and can be directly installed. The voltage measurement is a non-invasive voltage measurement method, and the current transformer is an electromagnetic induction measurement method, without direct contact with the cable. The installation does not require power cut. The temperature sensor is integrated inside the mutual inductor, and the temperature can be measured after the mutual inductor is installed, with high safety performance. Description of the Drawings

[0019] In order to more clearly illustrate the solution of the present utility model, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are some embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained according to these drawings without creative efforts.

[0020] Figure 1 It is a structural block diagram of an intelligent mutual inductor provided by an embodiment of the present utility model;

[0021] Figure 2 Schematic diagram of the traditional monitoring scheme for the low-voltage distribution room

[0022] Figure 3 Explosion diagram of an intelligent current transformer provided by an embodiment of the present utility model

[0023] Figure 4 Schematic diagram of the voltage measurement module and temperature measurement module of an intelligent current transformer provided by an embodiment of the present utility model

[0024] Figure 5 Front schematic diagram of the voltage induction copper sheet of an intelligent current transformer provided by an embodiment of the present utility model

[0025] Figure 6 Back schematic diagram of the voltage induction copper sheet of an intelligent current transformer provided by an embodiment of the present utility model

[0026] Reference numerals: 101 - First upper housing; 102 - Second upper housing; 103 - Fixing part for the upper and lower housings of the current transformer; 104 - First lower housing; 105 - Second lower housing; 106 - Printed circuit board; 107 - Voltage induction copper sheet; 108 - First current magnetic core; 109 - Second current magnetic core; 110 - Cable fixing part. Detailed implementation manners

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present utility model belongs; the terms used in the description of the present utility model in this specification are only for the purpose of describing specific embodiments and are not intended to limit the present utility model. For example, the terms such as "length", "width", "upper", "lower", "left", "right", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate the orientation or position based on the orientation or position shown in the drawings, and are only for convenience of description and cannot be construed as a limitation to the technical solution of the present application.

[0028] The terms "comprise" and "have" and any variations thereof in the description, claims and above-mentioned drawings of the present utility model are intended to cover non-exclusive inclusion; the terms "first", "second", etc. in the description, claims or above-mentioned drawings of the present utility model are used to distinguish different objects and are not used to describe a specific order. In the description, claims and above-mentioned drawings of the present utility model, when an element is referred to as "fixed to" or "mounted on" or "disposed on" or "connected to" another element, it may be directly or indirectly located on the other element. For example, when an element is referred to as "connected to" another element, it may be directly or indirectly connected to the other element.

[0029] In addition, the mention of "embodiment" in this text means that the specific features, structures, or characteristics described in connection with the embodiment can be included in at least one embodiment of the present utility model. The occurrence of this phrase at various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0030] The present utility model provides an intelligent current transformer, which is applied to the power energy monitoring system of a low-voltage distribution room. The intelligent current transformer includes:

[0031] A voltage measurement module, which is used to measure the voltage on the line to be measured and amplify the voltage to a signal range that can be sampled by the microcontroller module; a temperature measurement module, which is used to measure the temperature by measuring the change in the partial voltage generated by the change of the thermistor; a power supply module, which is used to provide power for each module of the intelligent current transformer; a microcontroller module, which is used for voltage measurement value calculation and correction, temperature measurement value calculation and correction, and transceiver command processing of the 485 communication module; a 485 communication module, which is used for transceiver communication with the microcontroller module; a current output control module, which is used to output a short circuit of the line through a current transformer to reduce the current value of the parallel circuit; the voltage measurement module, the temperature measurement module, the power supply module, the 485 communication module, and the current output control module are respectively communicatively connected to the microcontroller module.

[0032] The present utility model has a high integration degree, a relatively low cost, can be installed without power outage, and has a high safety performance.

[0033] In order to enable those skilled in the art to better understand the solution of the present utility model, the technical solutions in the embodiments of the present utility model will be clearly and completely described below in conjunction with the accompanying drawings.

[0034] The present utility model provides an intelligent current transformer, which is applied to the power energy monitoring system of a low-voltage distribution room. In combination with Figure 1 、 Figures 3 to 6 , in this embodiment, the intelligent current transformer includes:

[0035] The voltage measurement module is used to measure the voltage on the line to be measured and amplify the voltage to the signal range that can be sampled by the microcontroller module; the temperature measurement module is used to measure the temperature by measuring the change in the divided voltage generated by the change of the thermistor; the power supply module is used to supply power to each module of the intelligent transformer; the microcontroller module is used for voltage measurement value calculation and correction, temperature measurement value calculation and correction, and transceiver command processing of the 485 communication module. It uses the RENESAS RN8211B chip, integrates a 32-bit ARM Cortex-M0 core and a metering module, and has 128KB of FLASH, 8KB of SRAM and 32KB of EEPROM; the 485 communication module includes a 485 transceiver and an isolation circuit, and is used for transceiver communication with the microcontroller module; the current output control module is used to reduce the current value of the parallel circuit by short-circuiting the output line of the current transformer; the voltage measurement module, the temperature measurement module, the power supply module, the 485 communication module, and the current output control module are respectively communicatively connected to the microcontroller module.

[0036] Further, in this embodiment, the voltage measurement module includes a voltage sensor and a voltage measurement circuit. The voltage sensor includes a voltage induction copper sheet 107 and a coupling sampling capacitor. The voltage measurement circuit includes a two-stage amplifier and a data processor. The voltage induction copper sheet 107, the coupling sampling capacitor, the two-stage amplifier, and the data processor are connected in sequence. The non-invasive voltage measurement method is used to measure the voltage on the line to be measured, and the two-stage amplifier amplifies the coupling voltage to the signal range that can be sampled by the microcontroller ADC.

[0037] Further, in this embodiment, the temperature measurement module includes a temperature sensor and a temperature measurement circuit. The temperature sensor includes a temperature sensing resistor. The temperature measurement circuit includes a voltage-dividing sampling resistor and a data processor. The temperature sensing resistor, the voltage-dividing sampling resistor, and the data processor are connected in sequence. The temperature sensor uses a PT100 sensor, and the resistance value of the temperature sensing resistor changes with the temperature of the line to be measured. The temperature measurement circuit restores the temperature by measuring the change in the divided voltage generated by the change of the temperature sensing resistor.

[0038] Further, in this embodiment, the power supply module includes an external input 12V power supply for powering the microcontroller module, a DC / DC voltage conversion circuit for powering the 485 communication circuit, and a charge pump circuit for powering the voltage measurement circuit.

[0039] Further, in this embodiment, the current output control module includes a current control switch and a sampling resistor for the backend device circuit. The current control switch, the sampling resistor for the backend device resistor, and the current transformer are connected in parallel. By short-circuiting the output line of the current transformer, the current value of another parallel circuit is reduced.

[0040] Further, in this embodiment, an indicator light module for displaying the working state of the intelligent transformer is further included, and the indicator light module is communicatively connected to the microcontroller module.

[0041] Further, in this embodiment, a first upper housing 101, a second upper housing 102, a transformer upper and lower housing fixing member 103, a first lower housing 104, a second lower housing 105, a printed circuit board 106, a first current magnetic core 108, and a second current magnetic core 109 are further included. The first upper housing 101 and the second upper housing 102 are fixedly connected by ultrasonic welding. The transformer upper and lower housing fixing member 103 is disposed outside the overall connection of the first upper housing 101 and the second upper housing 102. The first current magnetic core 108 is disposed inside the overall connection of the first upper housing 101 and the second upper housing 102. The first lower housing 104 is connected to the second lower housing 105. The second current magnetic core 109, the voltage induction copper sheet 107, the temperature induction resistor, and the printed circuit board 106 are all disposed inside the overall connection of the first lower housing 104 and the second lower housing 105.

[0042] Further, in this embodiment, a cable fixing member 110 is further included. The cable fixing member 110 is a fixing clamp with a movable clamping lock. By adjusting the knob, the clamping lock can move up and down to fix the cable according to the cable size, so that the cable is in full contact with the inner diameter surface of the lower housing of the intelligent transformer, improving the voltage measurement and temperature measurement accuracy.

[0043] In this embodiment, the second lower housing 105 of the intelligent transformer has two cable outputs. One cable is a 2-core cable. The output cables of the intelligent transformer are combined with the output cables of the B-phase current transformer and the C-phase current transformer to form six cables. The interface is an RJ11 interface. The cables respectively include the outputs of the three-phase current transformers, A-phase S1, S2, B-phase S1, S2, and C-phase S1, S2. The other cable is an 8-core cable. The interface is an RJ45 interface and respectively includes RS-485A, RS485B, two 12V power supply positives, two 12V power supply negatives, a zero line, and a reserved line.

[0044] In this embodiment, the measurement functions of the intelligent transformer are divided into voltage measurement and temperature measurement. The voltage measurement consists of a voltage induction copper sheet 107, a coupling sampling capacitor, and a data processor. During sampling, the voltage induction copper sheet 107 is embedded inside the intelligent transformer, and the intelligent transformer is installed on the phase line. The phase line passes through the hole of the intelligent transformer. The voltage induction copper sheet 107 senses the electric field change on the phase line, and the electric field change is transmitted to the coupling sampling capacitor through a coaxial cable. The signal is amplified to a range that can be accurately sampled by the microcontroller through a two-stage amplifier, and the actual voltage value of the phase line is restored after being calculated by the data processor. The temperature measurement consists of a temperature induction resistor, a voltage-dividing sampling resistor, and a data processor. During sampling, the temperature induction resistor is installed on the reserved opening of the intelligent transformer. After the intelligent transformer is installed on the phase line, the temperature induction resistor contacts the phase line cable. The resistance value of the temperature induction resistor changes with the temperature of the phase line cable. A sampling voltage is added to the temperature induction resistor and the voltage-dividing sampling resistor. When the resistance value of the temperature induction resistor changes, the voltage on the voltage-dividing sampling resistor also changes accordingly. The data processor samples the voltage across the voltage-dividing sampling resistor and calculates to restore the temperature of the phase line cable.

[0045] Furthermore, the voltage induction copper sheet 107 is divided into a front side and a back side. The front side includes the positive pole of the voltage induction copper sheet 107, the negative pole of the voltage induction copper sheet 107, a perforation for the temperature induction resistor, and a coaxial transmission cable interface. The back side includes the negative pole of the voltage induction copper 107. The size of the voltage induction copper sheet 107 is the same as the inner diameter surface size of the lower housing of the intelligent transformer. The positive pole of the voltage induction copper sheet 107 is used to capture the electric field change generated by the phase line. The negative pole of the voltage induction copper sheet 107 is connected to the neutral line to shield the electric field intensity signals other than the non-measured phase line. The perforation for the temperature induction resistor is used to install the temperature induction resistor. After the temperature induction resistor passes through the voltage induction copper sheet 107, it contacts the phase line cable on the inner diameter surface of the lower housing of the intelligent transformer for temperature measurement. The coaxial transmission cable is used to transmit the induction signal to the coupling capacitor. The positive pole of the voltage induction copper sheet 107 is connected to the positive pole of the coupling sampling capacitor, and the negative pole of the voltage induction copper sheet 107 is connected to the negative pole of the coupling sampling capacitor.

[0046] In this embodiment, the microcontroller can control the opening and closing of the current control switch. When the current control switch is not closed, the current transformer senses the primary-side current and outputs the secondary-side current. The secondary-side induced current flows out from S1, passes through the current sampling resistor of the backend device, and then flows back to the current transformer through S2. The backend device can restore the current value by measuring the voltage value across the sampling circuit R. When the current control switch is closed, since the current control switch is in parallel with the sampling resistor of the backend device and the internal resistance of the current control switch is extremely small, most of the secondary-side current generated by the current transformer will flow back to S2 through the current control switch loop, and the current value passing through the current sampling circuit of the backend device decreases significantly, resulting in the current value measured by the backend device approaching 0. By controlling the opening and closing of the current control switch, the control of the output signal of the current transformer is achieved.

[0047] Compared with the prior art, the intelligent current transformer described in the above embodiment usually requires power outage for construction in the prior art, which will affect the normal operation of the power system. Secondly, due to the need to install multiple monitoring instruments and lay a large number of cables, the complexity of wiring and the construction difficulty are relatively high, and the safety is relatively low. In addition, the cost of the monitoring instruments and their supporting sensors is also considerable, which may increase the investment cost of the entire monitoring system. The structure of the present utility model is simple and easy to install. The intelligent current transformer integrates voltage measurement, current measurement, and temperature measurement, with high integration. The current transformer is directly clamped on the cable without redundant cables and has a low cost. The present utility model is of an open-type installation, without the need for power outage, and can be directly installed. The voltage measurement is a non-invasive voltage measurement method, and the current transformer is an electromagnetic induction measurement method, without direct contact with the cable. The installation does not require power outage. The temperature sensor is integrated inside the current transformer, and the temperature can be measured after the current transformer is installed, with high safety performance.

[0048] Obviously, the above-described embodiments are only the preferred embodiments of the present utility model, rather than all embodiments. The preferred embodiments of the present utility model are given in the drawings, but do not limit the patent scope of the present utility model. The present utility model can be implemented in many different forms. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosed content of the present utility model more thorough and comprehensive. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing specific embodiments, or perform equivalent replacements for some of the technical features. Any equivalent structure directly or indirectly using the content of the specification and drawings of the present utility model in other related technical fields shall be within the scope of the patent protection of the present utility model by the same token.

Claims

1. An intelligent mutual inductor, characterized in that, Including: A voltage measurement module, which is used to measure the voltage on the line to be measured and amplify the voltage to the signal range that can be sampled by the microcontroller module; A temperature measurement module, which is used to measure the temperature by measuring the change in the partial voltage generated by the change of the thermistor; A power supply module, which is used to supply power to each module of the intelligent transformer; A microcontroller module, which is used for voltage measurement value calculation and correction, temperature measurement value calculation and correction, and transceiver command processing of the 485 communication module; A 485 communication module, which is used for transceiver communication with the microcontroller module; A current output control module, which is used to reduce the current value of the parallel circuit by short-circuiting the output line of the current transformer; The voltage measurement module, temperature measurement module, power supply module, 485 communication module, and current output control module are respectively communicatively connected to the microcontroller module.

2. An intelligent transformer according to claim 1, characterized in that, The voltage measurement module includes a voltage sensor and a voltage measurement circuit. The voltage sensor includes a voltage induction copper sheet and a coupling sampling capacitor. The voltage measurement circuit includes a two-stage amplifier and a data processor. The voltage induction copper sheet, coupling sampling capacitor, two-stage amplifier, and data processor are connected in sequence.

3. An intelligent mutual inductor according to claim 2, characterized in that, The temperature measurement module includes a temperature sensor and a temperature measurement circuit. The temperature sensor includes a temperature induction resistor. The temperature measurement circuit includes a voltage-dividing sampling resistor and a data processor. The temperature induction resistor, voltage-dividing sampling resistor, and data processor are connected in sequence.

4. An intelligent mutual inductor according to claim 1, characterized in that, The power supply module includes an external input 12V power supply for powering the microcontroller module, a DC / DC voltage conversion circuit for powering the 485 communication circuit, and a charge pump circuit for powering the voltage measurement circuit.

5. An intelligent mutual inductor according to claim 1, characterized in that, The current output control module includes a current control switch and a sampling resistor for the circuit of the rear-end device. The current control switch, the sampling resistor of the rear-end device, and the current transformer are connected in parallel.

6. An intelligent mutual inductor according to claim 1, characterized in that, It also includes an indicator light module for displaying the working state of the intelligent transformer. The indicator light module is communicatively connected to the microcontroller module.

7. An intelligent mutual inductor according to claim 3, characterized in that, It also includes a first upper housing, a second upper housing, a fixing part for the upper and lower housings of the transformer, a first lower housing, a second lower housing, a printed circuit board, a first current magnetic core, and a second current magnetic core. The first upper housing is connected to the second upper housing. The fixing part for the upper and lower housings of the transformer is arranged on the outside of the connection of the first upper housing and the second upper housing. The first current magnetic core is arranged on the inside of the connection of the first upper housing and the second upper housing. The first lower housing is connected to the second lower housing. The second current magnetic core, voltage induction copper sheet, temperature induction resistor, and printed circuit board are all arranged on the inside of the connection of the first lower housing and the second lower housing.

8. An intelligent mutual inductor according to claim 7, characterized in that, It also includes a cable fixing part, which is installed on the lower half of the intelligent transformer on the connection of the first lower housing and the second lower housing.

9. An intelligent mutual inductor according to claim 7, characterized in that, The voltage induction copper sheet is provided with a positive electrode of the voltage induction copper sheet, a negative electrode of the voltage induction copper sheet, a through hole for the temperature induction resistor, and a coaxial transmission cable interface.

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