Device for measuring active power in electrical circuits

Abstract

The invention relates to a DISP device for measuring active power in electrical circuits, said DISP device being notable in that it comprises AC current sensors, at least one voltage sensor T, and a concentrator CO connected in series by serial cables LS, said AC current sensors, said at least one voltage sensor T, and said concentrator CO thus forming a communication chain. Figure to be published with the abstract: Figure 3

Description

Title of the invention: Device for measuring active power in electrical circuits. Technical field of the invention

[0001] The present invention relates to a device for measuring active power in electrical circuits. More particularly, the invention finds an interesting application in monitoring consumption at the level of electrical sub-circuits in buildings. Technological background of the invention

[0002] Today, there are many devices for measuring active electrical power in a single-phase electrical circuit based on the measurement of current and voltage. There are also many devices for carrying out this measurement in the case of a three-phase circuit, based on the measurement of currents and voltages.

[0003] These devices can be used in particular to establish a diagnosis and precise monitoring of the electrical consumption of the main equipment in a building by separately measuring the electrical circuits corresponding to this equipment, thus making it possible to detect savings and to monitor the effect of energy control actions.

[0004] To measure several electrical circuits, typically at the distribution board level, many devices rely on a star configuration in which each current and voltage sensor is directly connected to a concentration point, which will be called a concentrator, in which the calculations are carried out.

[0005] A disadvantage of such devices is that the number of connectors on the concentrator side is large, which generates a significant manufacturing cost. In addition, the many long cables connecting the current and voltage sensors to the concentrator are difficult to position in the case of installation in an electrical panel.

[0006] To measure several circuits, other devices consist of several concentration points connected to each other, each concentrator only calculating one power.

[0007] A disadvantage of such devices is the bulkiness due to the use of many concentration points, while distribution boards often offer little free space. In addition, the multiplication of concentration points generates significant material costs.

[0008] Many devices use current loops that must be positioned by hand by placing the fingers close to the conductor to be measured or adjacent conductors.

[0009] Furthermore, in many devices, these current loops have a significant thickness that does not allow easy positioning when the conductor does not have a sufficiently long straight section, in particular when it is curved towards the rear of the electrical panel at the output of the circuit breaker.

[0010] Furthermore, in many devices, these current loops have an articulated part that must completely surround the conductor before it can be closed.

[0011] A disadvantage of such devices is therefore the difficulty of installing the current loops and the reluctance of users to approach their fingers to the conductors. Summary of the invention

[0012] In this context, the invention aims to provide an active power measuring device that avoids multiplying the concentrators or connectors at each concentrator, in order to significantly reduce the installation time and therefore the total cost of the solution.

[0013] The invention therefore relates to an active power measuring device in which: a. Current sensors, voltage sensors and a concentrator are connected in series, thus forming a chain b. Each voltage sensor measures the voltage and transmits information relating to this voltage measurement along the chain c. Each current sensor receives the information relating to the voltage measurement that concerns it and performs its own active power calculation d. Each current sensor transmits the calculated power values ​​to the hub along the chain

[0014] The invention also aims to provide an easy means of positioning the current sensors.

[0015] The invention relates to a device whose current sensors can be opened from the front and can be actuated by removable clamps.

[0016] The measuring device according to the invention makes it possible to solve the problems previously mentioned.

[0017] Indeed, the device comprises current and voltage sensors which each include a processing unit and connectors allowing them to be connected in series. The concentrator also includes a processing unit and a connector allowing it to be connected to the end of the chain. Thus the device includes cables that are on average much shorter and less bulky, since they are used to connect the sensors one after the other and not each sensor to a hub. In addition, the hub may have only one connector.

[0018] Furthermore, the forward opening of the sensors and the use of removable jaws make it possible to open the sensor, position it around the conductor and close it without difficulty and without apprehension since the fingers remain at a distance from the conductors to be measured.

[0019] Each sensor is capable of measuring, performing calculations and managing the communication of information on the line.

[0020] The measuring device according to the invention may also have one or more of the following characteristics, considered individually or in all technically possible combinations.

[0021] According to a non-limiting embodiment, the current sensors are small open loops that can be easily positioned around the conductor to be measured.

[0022] According to a non-limiting embodiment, the current sensors consist of two removable parts each comprising a half-loop for measuring the electromagnetic field, these two parts being able to be separated to pass the conductor to be measured and being brought together, thus establishing an electrical contact making it possible to connect the two half-loops.

[0023] According to a non-limiting embodiment, a half-loop is a measuring half-winding.

[0024] According to a non-limiting embodiment, the current sensors consist of three elements, two of them each comprising a measuring half-winding and the third comprising the processing electronics, each of the two half-winding elements being connectable to the processing element and at least one of the half-winding elements being able to be separated so as to pass the conductor to be measured.

[0025] According to a non-limiting embodiment, each half-winding element is a Rogowski PCB, defined as a PCB board carrying a Rogowski half-winding formed of tracks on both sides of the PCB and vias connecting them.

[0026] According to a non-limiting embodiment, the current sensors are made up of three PCB boards, two of which are Rogowski PCBs and the third is a processing PCB defined as a PCB comprising the processing electronics.

[0027] According to a non-limiting embodiment, each of the two Rogowski PCBs is connectable to the processing PCB and at least one of the Rogowski PCBs is removable and can be moved apart so as to surround the conductor to be measured, and the processing PCB comprises a spring connector making it possible to establish contact with a track located on the removable Rogowski PCB when the latter is brought closer.

[0028] One of the advantages of this embodiment is that the two Rogowski PCBs can be produced without any electronic components.

[0029] According to a non-limiting embodiment, the current sensors can be opened and closed using a clamp, said clamp comprising two articulated branches allowing the mechanical parts containing the half-winding elements to be moved apart and brought together.

[0030] According to a non-limiting embodiment, each half-winding element is secured to a plastic support comprising a rectangular hoop, so that the branches of the clamp can be temporarily inserted into these hoops and be actuated to move the two half-windings apart or together.

[0031] According to a non-limiting embodiment, the branches of the clamp comprise at their end a lateral stop projection capable of locking said branches in the hoops of the current sensor when said branches are separated, so as to be able to pull the assembly into the open position and thus remove the sensor from its initial position around a conductor. Brief description of the figures

[0032] Other features and advantages will emerge from the description below, made with reference to the drawings given as non-limiting examples and in which: a. [Fig. 1] is a schematic representation of the current sensor of the device in the closed position. b. [Fig. 2] is a schematic representation of the current sensor of the device in the open position. c. [Fig. 3] is a schematic representation of a chain of several sensors positioned near a series of circuit breakers. d. [Fig. 4] is a schematic representation of the three PCBs, two of them each containing a half-winding and the third containing the processing electronics e. [Fig. 5] is also a schematic representation of the three PCBs, from a different viewing angle. f. [Fig. 6] is a schematic representation of the clamp used to position the sensor. g. [Fig. 7] is a schematic representation of the clamp pressed into the rectangular hoops of the sensor and holding the sensor in the open position. Detailed Description

[0033] The invention relates to a DISP device for measuring active power in electrical circuits. The DISP device comprises: a. AC current sensors b. Voltage sensors T c. A CO concentrator d. A clamp P for installation assistance

[0034] According to one embodiment, a CA sensor shown in Figures 1 and 2 consists of two assemblies ENS1 and ENS2 that can be moved apart and brought together so as to surround a conductor to be measured. The assembly ENS1 can slide along ENS2, the moving apart and the bringing together can thus be carried out while the two assemblies remain integral. The circular notches EC1 and EC2 constitute a circular orifice surrounding the conductor to be measured when ENS1 and ENS2 are brought together.

[0035] When the ENS1 and ENS2 assemblies are separated, the AC sensor can be slid around the conductor to be measured and then closed once the circular notches EC1 and EC2 are at the level of the conductor to be measured.

[0036] The ENS1 assembly includes a lug ERG and the ENS2 assembly includes an orifice OR. When the ENS1 and ENS2 assemblies are brought together as closely as possible, the lug ERG clips into the orifice OR, thus keeping the device closed.

[0037] [Fig. 3] shows the DISP device positioned on a series of five circuit breakers D.

[0038] The CA sensors are positioned around the conductors to be measured CM, which come out of the circuit breakers. The voltage sensor T is positioned at the screws of one of the circuit breakers. The CO concentrator is positioned next to the series of circuit breakers.

[0039] The CA sensors, the sensor T and the CO concentrator are connected by the series cables LS, thus forming a chain.

[0040] In one embodiment, the sensor T measures the voltage at high frequency, for example at a frequency of 4000 Hz, and transmits the measured values ​​along the chain. The AC sensors measure the current at high frequency, for example at a frequency of 40000 Hz, and use the voltage values ​​transmitted by the voltage sensor to combine them with the current values ​​they measure in order to obtain an active power.

[0041] When the installation is supplied with three-phase power, three voltage sensors are used, one for each of the three phases. Each AC sensor is then configured to use the signals from the voltage sensor that corresponds to the correct phase. Each voltage sensor transmits its values ​​and each AC sensor identifies the origin of the voltage values ​​that are transmitted and only uses those originating from the correct voltage sensor.

[0042] In one embodiment, the voltage values ​​are first communicated to the CO concentrator, which then retransmits them to the AC sensors.

[0043] The AC sensors transmit along the chain, to the concentrator, the powers that they have calculated.

[0044] The concentrator receives the received values, processes them, for example to aggregate them temporally, stores the results obtained and transmits them at regular intervals, typically via a connection to a data network, such as an NB-loT or LoRaWAN wireless network.

[0045] The ENS1 assembly includes a half-winding PCB board PCBL. The ENS2 assembly includes a second half-winding PCB board PCB2 and a processing PCB board PCB 3.

[0046] The three PCB boards are shown in Figures 4 and 5.

[0047] The PCB3 board includes two connectors CS1 and CS2 intended to be connected to the serial link cables LS.

[0048] The PCB3 board comprises two spring connectors intended to ensure electrical contact between the PCB3 and the tracks of the PCB1 and PCB2. Thus, when the sensor is closed, that is to say when the assemblies ENS1 and ENS2 are brought together, the PCB1 and PCB2 boards are brought together and the CRI connector comes into contact with the tracks of the PCB1 board, so as to be able to measure the signal from the Rogowski half-coils carried by PCB1, in addition to the signal from the Rogowski half-coil carried by PCB2.

[0049] [Fig.6] represents a specific clamp P intended to facilitate the installation of the CA sensors.

[0050] The clamp comprises two branches BRI and BR2 articulated around an axis AX.

[0051] The P clamp can be manipulated so as to introduce the BRI and BR2 branches into the AR1 and AR2 rectangular hoops of the CA sensor.

[0052] The clamp P then allows the CA sensor to be opened or closed by moving the assemblies ENS1 and ENS2 apart or closer together.

[0053] The BRI branch includes a stop projection BU1. The BR2 branch includes a stop projection BU2.

[0054] [Fig.7] shows the BRI and BR2 branches of the clamp P, inserted into the rectangular arches AR1 and AR1 of the CA sensor. The clamp P is in the open position, branches apart, which induces an open position of the CA sensor.

[0055] The stop projections BU, BU2 allow the CA sensor to be removed from its position around the conductor. In the open position, the stop projections BU, BU2 protrude from the lateral sides of the rectangular hoops AR1, AR1 and thus provide a lock allowing the CA sensor to be pulled using the clamp P, even in the event of resistance from various friction or obstacles.

Claims

Claims

1. Device (DISP) for measuring active power in electrical circuits, said device (DISP) being characterized in that it comprises current sensors (CA), at least one voltage sensor (T) and a concentrator (CO) connected in series by serial cables (LS), said current sensors (CA), said at least one voltage sensor (T) and said concentrator (CO) thus forming a communication chain.

2. Device (DISP) according to the preceding claim, characterized in that each voltage sensor (T) is configured to measure a voltage of a phase and transmit information relating to a voltage measurement along the communication chain.

3. Device (DISP) according to the preceding claim, characterized in that each current sensor (CA) is configured to measure a current of a phase, receive information relating to a voltage measurement of this phase and carry out its own active power calculation.

4. Device (DISP) according to claim 3, characterized in that each current sensor (CA) is further configured to transmit calculated active power values ​​to the concentrator (CO).

5. Device (DISP) according to any one of the preceding claims, characterized in that each current sensor (CA) comprises three elements (PCB1, PCB2, PCB3), two of the three elements (PCB1, PCB2) each comprising a measuring half-winding and the other of the three elements (PCB3) comprising processing electronics, each of the two elements (PCB1, PCB2) comprising a measuring half-winding being configured to be electrically connected to said element (PCB 3) comprising processing electronics and at least one of said two elements (PCB1, PCB2) comprising a measuring half-winding is configured to be spaced apart to surround a conductor to be measured.

6. Device (DISP) according to the preceding claim, characterized in that the element (PCB3) comprising processing electronics comprises at least one spring connector configured to establish electrical contact with at least one of said two elements (PCB1, PCB2) having a measuring half-winding configured to be displaced

7. Device (DISP) according to claim 5 or 6, characterized in that each element (PCB1, PCB2) having a measuring half-winding is formed by a printed circuit board carrying a Rogowski half-winding.

8. Device (DISP) according to any one of claims 5 to 7, characterized in that each element (PCB1, PCB2) having a measuring half-winding is secured to a plastic support having a rectangular frame (AR1, AR2), each rectangular frame (AR1, AR2) being configured to receive a branch (BRI, BR2) of a clamp (P).

9. Clamp (P) comprising two branches (BRI, BR2) articulated around an axis (AX), each branch (BRI, BR2) being configured to be temporarily inserted into one of the arches (AR1, AR2) of the current sensor (CA) that a device (DISP) comprises according to the preceding claim.

10. Clamp (P) according to the preceding claim, characterized in that the branches (BRI, BR2) of the clamp (P) comprise at their end a lateral stop projection (BU1, BU2) configured to block said branches (BRI, BR2) in said arches (AR1, AR2) of the current sensor (CA) when said branches (BRI, BR2) are separated.

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