CZ201829A3 - A device for sensing the status of electronic electrometers, a method of sensing the status of electronic electrometers, a procedure for sensing the status of electrometers and the use of the device - Google Patents

Abstract

The device for continuous reading of the status of electronic meters consists of a battery (1), a power supply (2), a processor unit (3), a wireless communication module (4), a battery monitor (5), an optical communication interface (6), an antenna ( 7) and the protection circuit (8), wherein the blocks or elements are collectively used to collect and transmit data obtained from conventional electronic meters, where a low-power high-range network (LPWAN) is used for data transmission, which has extremely low building costs and operation, wherein the compact device is preferably provided with a removable magnet mount, using an optical port for obtaining data from the meter.

Description

Device for sensing the status of electronic meters, method of sensing the status of electronic meters, process of sensing the status of meters and using the device

Technical field

BACKGROUND OF THE INVENTION The present invention relates to a device and its mechanical construction and its electrical connection for detecting electronic electricity meter status information (particularly measured electrical energy consumption and related information) via an optical communication interface and remote transmission of such information via LPWAN low power radio network to a cloud data storage.

BACKGROUND OF THE INVENTION

The optical (IR) port of modern electronic electricity meters is currently used mainly for one-off readings (typically once a year) of the state of electricity consumption. energy to the supplier for billing purposes or for diagnostic or service purposes. Continuous metering and provision of this information to consumers online suppliers either do not address it at all or use special, technically complex and expensive electricity meters equipped with some "standard" communication technologies (GSM / GPRS, Wi-Fi, MBus wireless) - for example Landis + Gyr ZMF100. Currently available solutions enabling online monitoring of power consumption. energy by reading information from electricity meters, they use optical pulse output to collect consumption information, the disadvantage of which is the necessity of initial "manual" setting of software counters, conversion factor and subsequent error-free synchronization (loss of even a single pulse = loss of synchronization) ). They require a complicated infrastructure based on the WiFi communication standard, a 230 V power supply and a data concentrator to transmit information - see, for example, the Energomonitor project.

Description of the invention

The basic idea is that the device uses state-of-the-art IoT technology to design and operate a very inexpensive, affordable device for collecting, transmitting, presenting and processing data obtained from conventional electronic energy meters. Data transmission uses a low-power long-range network (LPWAN), characterized by extremely low construction and operation costs. Examples of the invention include:

miniature, compact device powered by AA battery accumulator el. energy communicating data over a low-energy, low-cost, low-cost LoRaWAN LPWAN to a cloud storage with a removable magnet mount using an optical port in accordance with IEC 62056-21 for data acquisition from the meter.

Description of the connection of the device according to the invention

The device according to the invention serves for automatic contactless data collection from electricity meters and their wireless transmission via low-power radio network to the central server. The data can be further freely processed, both for personal use and for electricity distributors. Emphasis is placed on maximum ease of installation and registration of the device in the network, as well as the creation of a user account and display of measured values.

- 1 GB 2018 - 29 A3

The whole device is powered by a battery, preferably a lithium battery with a nominal voltage of 3.6 V, the advantage of which is a very long lifetime and allows the device to function, with an average consumption of about 20uA, in a number of years. In the case of a power source with similar or better parameters, the present invention is not limited to a lithium battery, but other suitable power sources may also be used to power. The battery is fed into the protective circuit. This part contains a semiconductor diode, which serves as protection against polarity reversal of the battery (eg when replaced by the user). The semiconductor diode transmits electric current, according to the present invention, supplied by the battery in only one direction, from anode to cathode. If there is reverse polarization voltage on the semiconductor diode, ie when the positive and negative supply voltage terminals are switched, the diode is polarized in the so-called reverse direction and transmits the minimum current in the order of μΑ units, known as the so-called reverse current. This reverse current, due to its size, will not jeopardize any other parts of the device.

Since the above-described battery is capable of supplying up to tens of amperes in the event of a short circuit and could cause the device to ignite due to the passage of this extremely high current, a polymer return fuse is connected in the protective circuit behind the semiconductor diode. This fuse disconnects the battery from the device when the current increases, and protects both the battery and other parts of the device in the event of an electrical fault on the device. In addition, the polymer fuse has self-healing capability and once the supply voltage has been disconnected, the conductive state resumes itself, so there is no need to replace the fuse.

The protective circuit is followed by a power supply block. This part of the device mainly comprises a linear voltage stabilizer with a very low self-consumption and a very low voltage drop across this circuit. Other elements are blocking capacitors, which prevent the feedback of the linear voltage stabilizer from oscillating when either the input voltage is changed, and the device is battery-powered in this solution and therefore the input voltage is not changed in front of the stabilizer. stabilizer. Because one of the device's goals is extremely long life, most of the time, both the processing unit and the communication module are in the Low power mode and the power consumption of the device is of the order of microamps. However, during communication with the meter and when sending data over a radio connection, there is a momentary increase in power consumption up to tens of milliamperes. Here the influence of the blocking capacitors is applied, which prevents the feedback of the linear stabilizer feedback and the loss of the stabilizing capabilities of this circuit.

The output voltage from the linear stabilizer, which supplies all other parts of the device where the stabilizer is part of the power supply unit block, is 2.5 V. Thanks to the above described characteristics of the stabilizer, ie very low self-consumption and very low voltage drop, to operate from 2.7 V

The battery voltage monitoring unit is connected to the protective circuit and consists of a resistive voltage divider and an operational amplifier. A voltage divider consisting of two high-resistor resistors of the order of megaohms ΜΩ will reduce the measured battery voltage to a value given by the ratio of the resistor resistance values in the voltage divider, which is then suitable for further processing by the processor unit. Due to the high resistance value of the resistors in the divider, the current flowing through these elements is very low, ie less than one μΑ microampa, and therefore does not burden the battery and reduce its battery life. However, large resistance values cause the voltage divider to have a very high output resistance and cannot be connected directly to the analog-to-digital converter contained in the processor unit because its input resistance is in the order of tens of kiloohms (1 <Ω) and would cause great distortion measured quantities that would become unusable. Operational amplifier used as impedance separator solves this problem. This circuit has an extremely high input resistance in the order of tens of takže, so that the voltage divider does not load current, and vice versa has almost zero output resistance and can then be connected to the analog-to-digital converter input of the processor unit without the entire battery voltage measurement measurement.

-2GB 2018 - 29 A3

The processor unit comprises a microprocessor that controls the operation of the entire device, preferably a 16-bit microprocessor with an extremely low power input of about 50 pW in the sleep state, where the microprocessor is about 95% of the time. It controls the communication module to access the low-power wireless network, controls the communication process with the electricity meter through the optical communication interface, and also monitors the battery voltage using an integrated analog-to-digital converter. It is basically a finite state machine. After switching on or restarting the microprocessor, all the peripherals used are set first, and above all the special timer that is part of the processor unit and remains the only one running even in the most successful mode of the microprocessor when almost all its parts are switched off. .

In the main loop, an attempt is always made first to establish communication with the meter. If this attempt is successful, the data is sent to the server through a wireless low-power network (see below). Subsequently, the entire microprocessor switches to a very low power mode with only a special timer running. After a defined period of time, typically 10 minutes, this timer resets the processor to the active state. The whole process is repeated over and over. Next, the battery voltage is checked and the status is sent in the data packet along with the meter data.

The optical communication interface is used to transfer information between the device and the meter. It is directly connected to the processor unit that ensures its control. It consists of a phototransistor and LED, both elements operating in the near-infrared spectrum, about 880 nm. The IR (infrared) LED emits infrared radiation as it passes through electrical current and serves as a transmitting element. The excitation current is set to approximately 10 mA with a resistor, which is a good compromise between power consumption and transmitted power. The IR LED is not connected directly to the processor unit, but is switched via a bipolar PNP transistor. The microprocessor output port has a limited maximum output current, the use of a PNP transistor allows a small current from the microprocessor output pin to switch a larger current through the flowing IR LED. The current sensing element, e.g. preferably by an IR phototransistor, starts to flow under irradiation with infrared radiation, opening it. The phototransistor is connected between the zero potential of the GND (ground) and the pull up resistor, which is supplied with a 2.5 V supply voltage. If the sensitive area of the semiconductor is illuminated by infrared radiation, the phototransistor starts conducting current and logic appears on the microprocessor value of “L” indicating voltage of 0 V. If the semiconductor is not illuminated, the phototransistor is closed and the logic value of “H” indicating the voltage of 2.5 V is output. This way serial communication between the device and the meter takes place. In this type of transmission, communication begins by sending a start bit with a logical value of "L", followed by individual bits from the transmitted byte, and the transmission ends with a stop bit with a logical value of "H". The infrared signal is not modulated.

The wireless communication module ensures the transmission of measured data via an antenna to a low-power LPWAN wireless network to the cloud storage. It contains the modulator, demodulator, and carrier frequency circuits. The modulator circuitry is used to generate a high frequency signal with a modulated data packet to be sent from the device. The output from the modulator circuits is connected to an output amplifier that provides the required transmit power and is connected to the antenna. The antenna is also connected to the input Low Noise Amplifier LNA, which amplifies the signal received into the device. Its output is connected to a demodulator, which demodulates the RF signal and converts it to a data packet that is processed by the processing unit. In addition to the modulator and demodulator circuits, the wireless communication module also includes a carrier frequency generator consisting of a crystal oscillator, a voltage-controlled oscillator, and a phase lock. The crystal oscillator, together with the Voltage Controlled Oscillator VCO and Phase Locked Loop PLL, generates the exact frequency for the modulator and demodulator circuits. The crystal oscillator operates on the principle of oscillation of the piezoelectric body when two opposing electrodes are energized. The size and shape of the crystal determines the resonance frequency that the crystal oscillator then generates.

-3 EN 2018 - 29 A3

The phase oscillator of the crystal oscillator, which is part of the wireless communication module, is a feedback circuit designed to maintain the output phase of the signal with the input signal. Its output is connected to a voltage-controlled oscillator via a low-pass filter (this filter only transmits signals to a certain frequency limit). Its output signal at the frequency corresponding to the control voltage is applied via a divider (N) to the first input of the phase detector and to the second input the signal from the crystal oscillator. This connection provides a voltage at the input of the voltage-controlled oscillator such that its output frequency is equal to the frequency of the crystal oscillator multiplied by the constant N corresponding to the dividing ratio of the divider. Thus, a signal with an exact frequency for the modulator is synthesized. The same frequency is used in the demodulator for the received signal.

The wireless communication module in the basic design consists of one integrated circuit. In another embodiment, it may be represented by a plurality of integrated circuits that together form the communication module.

In the basic design, the antenna is connected directly to the printed circuit board by means of a screw connector and forms one compact unit with the external housing of the device, eg a housing. There may be situations where the antenna needs to be routed through a cable outside the cabinet where the meter is located. In this case, the antenna can be connected to the device via a cable.

The device is preferably attached to the electricity meter by means of a magnetic element provided in the region of the output of the optical communication interface. Any other method of fastening the device allowing the connection of the optical communication interface to the electricity meter is not excluded by the present invention, but the magnetic connection of the device according to the invention and the electricity meter seems to be the most advantageous variant.

If necessary, the device may be provided with an optical or metallic cable to remotely connect the device to the meter. The metallic cable according to such a solution comprises circuits that convert the optical signal to electrical signal in both directions. Such a solution is generally disadvantageous and considerably more complex, expensive and energy intensive, only suitable for situations where there is no clearance in front of the meter to allow installation of the device according to the invention. However, the device according to this solution is so small that it fits into virtually any electrical cabinet with an electricity meter, which means that if the probe itself fits there, the entire device according to the invention can also fit there.

Advantages over the prior art:

Modern remote access to power consumption information Energy: The device enables continuous reading of the state from conventional electronic meters equipped with an optical interface (in the example of the invention according to IEC 62056-21) and sending this information at preset intervals to the cloud storage for further processing. Subsequently, the data are available continuously in numerical and graphic form in physical units of electrical work (kWh) and financial expression (CZK) to web browsers of computers, tablets and smartphones.

Economical: the device can be equipped with a very fast majority of commonly used electricity meters with a magnet - so it is not necessary to replace them with new expensive communication interface devices to get online consumption information.

Affordability: the device itself is completely maintenance-free (in the exemplary embodiment of the invention, in addition to a battery replacement, approximately once every 2-3 years), simple and affordable to the widest range of users (in the exemplary embodiment). Network traffic is also cheap - LPWANs (so-called Low Power WANs) are not expensive to build or operate, the current cost of transmitting information from one device does not exceed 1 Eur per month in an exemplary embodiment of the invention.

-4GB 2018 - 29 A3

Technical maturity: the device is developed on the most advanced technologies both in terms of electronics design (low-energy components, battery power) as well as the architecture of the related infrastructure (IoT networks, cloud storage, web access), enabling the development of a solution that does not require installation and operation practically no specific user knowledge.

High utility value: the user has the possibility to obtain a continuous overview of electricity consumption at minimum cost. energy in its object. After entering a few (approx. 4 according to the supplier in the example of implementation of the invention) values, it is possible to convert consumption information for the selected time period from physical units directly to currency units (CZK, Eur,). . It is possible to set consumption limits for the selected period and after its exceeding generate automatic alerts in the form of e-mails or sms messages, similarly in case of a negative balance, if the user receives a warning after a billing period. The warning can of course be linked to the user preset values.

Summary of advantages:

The device according to the invention solves the following problems:

accurate, continuous measurement of power consumption energy reading data directly from the meter; transmission of consumption information via modern LPWAN radio network to cloud storage; presentation of the collected data online in real time via a web browser on both classic computers and mobile smartphones (phones, tablets).

The device according to the invention, which performs continuous readings of meters of meters (or other quantities provided by the meter) has the following utility properties:

in accordance with Directive 2009/72 / EC of the European Parliament and of the Council of

13 July 2009 on common rules for the internal market in electricity provides consumers with proper information on electricity consumption. energy costs and often enough to efficiently regulate their consumption.

This is an innovative solution that:

it is structurally very simple, cheap - very affordable;

no tools or technical knowledge is required for its installation; mounting on the optical port by means of a magnet makes it easy to remove and fit; By using the communication standard (DLMS standard is used in the embodiment of the invention), data consistency is ensured even when the equipment is temporarily removed (for example, by a power supplier for a one-off reading of power consumption).

It uses a modern low-cost low-power radio network (Low Power WAN) with a long range (LoRaWAN, SigFox or NB IoT), which allows the battery to last for at least 2 years (according to adjustable frequency of readings and transmissions). In an exemplary embodiment of the invention, a LoRaWAN network is used.

Clarification of drawings

Giant. 1 shows a device according to the invention with an electricity meter;

Giant. 2 shows a general diagram of the main elements of the apparatus;

Giant. 3 shows a detailed circuit diagram of all elements of the device.

-5 EN 2018 - 29 A3

DETAILED DESCRIPTION OF THE INVENTION

Example 1

The device for continuously sensing the state of the electronic meters according to FIG. 1 consists of the following parts and / or elements:

battery 1 resp. accumulator el. energy;

power supply sources 2;

- processor units 3;

a wireless communication module 4;

monitor 5 battery voltage respectively. accumulator el. energy;

an optical communication interface 6;

antennas 7 a

- a protective circuit 8;

Example 2

The device of FIG. 2 and according to Example 1, wherein the battery 1 is a 3.6 V lithium battery, wherein the power supply 2 comprises a linear voltage stabilizer 2a and blocking capacitors 2b, wherein the processing unit 3 consists of a microprocessor 3a, an analog to digital converter 3b; a timer 3c wherein the wireless communication module 4 consists of a crystal oscillator 4a, a phase lock 4b, a voltage controlled oscillator 4c, a demodulator 4d, a low noise amplifier 4e, and a modulator 4f wherein the battery voltage monitor 5 consists of a resistive divider 5a and an operational amplifier 5b the communication interface 6 consists of a phototransistor 6a and an LED 6b, an IR intensity resistor 6c, a bipolar transistor 6d and wherein the protective circuit 8 is formed by a semiconductor diode 8a and a polymer fuse 8b.

Example 3

The apparatus of Example 2, wherein the source 2 has an output voltage of 2.5 V. Microprocessor 3a is a 16-bit microprocessor with extremely low power consumption. Communication module 4 serves for access of low-power wireless LPWAN network, especially LoRaWAN, SigFox or NB IoT and enables continuous reading of status from common electronic meters equipped with optical interface according to IEC 62056-21 standard and sending this information at preset time intervals to the cloud storage for further processing. Phototransistor 6a and LED 6b operate in the IR spectrum at approximately 880 nm. The excitation current is set to approximately 10 mA using a resistor 6c.

Example 4

The apparatus of FIG. 1 is preferably attached to the electricity meter by a magnetic element provided in the region of the output of the optical communication interface 6.

Example 5

The device according to any of the preceding examples, wherein the wireless communication module 4 comprises

-6GB 2018 - 29 A3 at least one integrated circuit.

Example 6

The device according to any of the preceding examples, wherein the antenna 7 is connected to the printed circuit board of the device by means of a screw connector and forms one compact unit with the outer shell of the device or is connected to the printed circuit board of the device by an external cable.

Example 7

The apparatus of any of the preceding examples, wherein the apparatus is provided with an optical or metallic cable for remotely connecting the apparatus to the meter.

Example 8

The method of sensing the status of electronic meters via an optical interface comprises the following steps expressed in points:

emitting infrared radiation by the LED 6b of the optical communication interface 6 as the current passes, the LED 6b being switched by a bipolar transistor 6d of the PNP type connected to the output of the processing unit 3, thereby ensuring an output current of about 1mA from the output pin of the processing unit 3, the current flowing through the IR LED 6b is about 10 mA, necessary to generate an infrared intensity sufficient to excite the phototransistor on the receiver side of the optical communication interface 6 in the electricity meter, the excitation current being adjusted to about 10 mA by the resistor 6c. ;

receiving the signal via the optical communication interface receiving element 6, which is an IR phototransistor 6a, which, when irradiated from the opposite side of the optical communication interface in the electricity meter, starts to flow and opens, the phototransistor 6a being connected between zero GND (ground) and pull up resistor to which a 2.5 V supply voltage is applied, whereas if the sensitive area of the semiconductor is illuminated by infrared radiation, the phototransistor 6a starts to conduct current and the output of the circuit connected to microprocessor 3a displays a logic value of 0 L , and if the semiconductor is not illuminated, the phototransistor is closed and the logic value "H" corresponds to a voltage of 2.5 V;

processing of the logical values "L" and "H" in the processor program of the processor unit 3 such that the communication starts by sending a start bit with logical value "L", followed by individual bits from the transmitted byte, and Thereby reading data from the electricity meter into the processor unit 3;

selecting the desired consumption data from the meter by the processor program of the processor unit 3;

forwarding data via the output port to the wireless communication module 4 for transmission to the cloud storage.

Example 9

The meter reading procedure is controlled by a finite state machine, which is implemented in the software in the control unit and is performed in the following steps:

in the main loop, an attempt is always made first to establish communication with the meter; if this attempt is successful, the data is sent to the server through a wireless low power

-7 GB 2018 - 29 A3 net;

subsequently, the entire microprocessor 3a is switched to a very low power mode with only the special timer 3c running;

after a defined time of 10 min, this timer 3c restores the processor 3a to an active state;

in addition, the battery voltage 1 is checked and the status is sent in a data packet together with meter data;

the whole process is repeated over and over.

Example 10

Use of the apparatus of Examples 1 to 7 to sense the status of electronic meters via an optical interface and to provide wireless transmission of this status information via an LPWAN radio network to the cloud storage.

Industrial applicability

The method of sensing data and equipment is useful for sensing the status of electronic meters via an optical interface and providing wireless transmission of this status information via an LPWAN radio network to, for example, a cloud storage.

PATENT CLAIMS

Claims (17)

An apparatus for continuously sensing the condition of electronic meters, characterized in that it consists of the following parts and / or elements: batteries (1); power supply sources (2); processing units (3); a wireless communication module (4); a battery voltage monitor (5); an optical communication interface (6); the antenna (7) and the protective circuit (8). Device according to claim 1, characterized in that the battery (1) is a 3.6 V lithium battery. Device according to claim 1, characterized in that the source (2) comprises a linear voltage stabilizer (2a) and blocking capacitors (2b). Device according to claim 1, characterized in that the processing unit (3) consists of a microprocessor (3a), an analog to digital converter (3b) and a timer (3c). Device according to claim 1, characterized in that the wireless communication module (4) consists of a crystal oscillator (4a), a phase lock (4b), a voltage-controlled oscillator (4c), a demodulator (4d), a low noise amplifier (4e) and modulator (4f). Device according to claim 1, characterized in that the battery voltage monitor (5) consists of a resistive divider (5a) and an operational amplifier (5b). CZ 2018 - 29 A3 Device according to claim 1, characterized in that the optical communication interface (6) consists of a phototransistor (6a), an LED (6b), a resistor (6c) and a bipolar PNP transistor (6d). Device according to claim 1, characterized in that the protective circuit (8) is formed by a semiconductor diode (8a) and a polymer fuse (8b). Device according to claim 1 or 3, characterized in that the source (2) has an output voltage of 2.5 V. The apparatus of claim 4, wherein the microprocessor (3a) is a 16-bit microprocessor with an extremely low power input of about 50 µW in the sleep state. Device according to claim 1 or 5, characterized in that the communication module (4) is connected via a low-power wireless LPWAN, in particular of the LoRaWAN, SigFox or NB IoT type, to a remote data storage, in particular a cloud storage. Apparatus according to claim 7, characterized in that the phototransistor (6a) and the LED (6b) are adapted to sense and emit infrared radiation at a wavelength of 870 to 950 nm. Device according to any one of claims 1 to 12, characterized in that the device is fixed to the electricity meter by means of a magnetic element provided in the region of the output of the optical communication interface (6). Device according to claim 1, 5 or 11, characterized in that the wireless communication module (4) forms at least one integrated circuit. Device according to any one of claims 1 to 12, characterized in that the antenna (7) is connected to the printed circuit board of the device by means of a screw connector and forms one compact whole or connected to the printed circuit board of the device by an external cable. . Device according to any one of claims 1 to 13, characterized in that the device is provided with an optical or metallic cable for the remote connection of the device to the electricity meter. 15. The method of sensing the status of electronic meters by means of an optical interface comprises the following steps expressed in points: - emitting infrared radiation by means of an LED (6b) of the optical communication interface (6) during the passage of electric current, the LED (6b) being switched by means of a PNP-type bipolar transistor (6d) connected to the output of the processing unit (3); that the output current of about 1 mA from the output pin of the processor unit (3) is switched by the current flowing through the IR LED (6b) of about 10 mA, necessary to generate an intensity of infrared radiation sufficient to excite the phototransistor on the receiver side of the optical communication interface 6 a meter, wherein the excitation current is adjusted to about 10 mA by a resistor (6c); - receiving the signal by means of an optical communication interface receiving element (6), which is an IR phototransistor (6a), which, when irradiated from the opposite side of the optical communication interface in the electricity meter, starts to flow and open it, the phototransistor (6a) being connected between zero GND potential (ground) and pull up resistor, which is supplied with a 2.5 V supply voltage, and if the sensitive area of the semiconductor is illuminated by infrared radiation, the phototransistor (6a) starts to conduct current and the output of the circuit connected to the microprocessor (3a) the logic value "L" appears with a nominal voltage of 0 V, and if the semiconductor is not illuminated, the phototransistor is closed and the logic value "H" is output corresponding to 2.5 V; -9GB 2018 - 29 A3 - processing the logical values "L" and "H" in the processor program of the processing unit (3) so that the communication starts by sending a start bit with a logical value "L", followed by individual bits from the transmitted byte, a value of "H", thereby reading data from the meter to the processing unit (3); - selecting the desired consumption data from the electricity meter by the processor program of the processing unit (3); - transferring data via the output port to the wireless communication module (4) for transmission to the cloud storage. 16. A meter reading process characterized in that it is controlled by a finite state machine that is implemented in the software in the control unit and is performed in the following steps: - the main loop always attempts to establish communication with the electricity meter; - if this attempt is successful, the data is sent to the server via a wireless low power network; - then the entire microprocessor (3a) switches to a very low power mode with only a special timer (3c) running; - after a defined period of time, preferably 10 min, this timer (3c) returns the processor (3a) to an active state; - the battery voltage (1) is further checked and the status is sent in a data packet together with the meter data; - the whole process is repeated over and over. Use of a device according to any one of claims 1 to 14 for sensing the status of electronic meters via an optical interface and providing wireless transmission of this status information via an LPWAN radio network, in particular a LoRaWAN, SigFox or NB IoT, to a remote data storage, particularly a cloud storage. .