WO2007080304A1 - Battery circuit breaker comprising current-measuring means - Google Patents

Battery circuit breaker comprising current-measuring means Download PDF

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Publication number
WO2007080304A1
WO2007080304A1 PCT/FR2007/000025 FR2007000025W WO2007080304A1 WO 2007080304 A1 WO2007080304 A1 WO 2007080304A1 FR 2007000025 W FR2007000025 W FR 2007000025W WO 2007080304 A1 WO2007080304 A1 WO 2007080304A1
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WO
Grant status
Application
Patent type
Prior art keywords
electrical
measuring
means
circuit breaker
current
Prior art date
Application number
PCT/FR2007/000025
Other languages
French (fr)
Inventor
Per-Anders Forsberg
Original Assignee
Diamecans
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date

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Classifications

    • GPHYSICS
    • G01MEASURING; TESTING
    • G01RMEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R1/00Details of instruments or arrangements of the types included in groups G01R5/00 - G01R13/00 and G01R31/00
    • G01R1/20Modifications of basic electric elements for use in electric measuring instruments; Structural combinations of such elements with such instruments
    • G01R1/203Resistors used for electric measuring, e.g. decade resistors standards, resistors for comparators, series resistors, shunts
    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01HELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H51/00Electromagnetic relays
    • H01H51/02Non-polarised relays
    • H01H51/04Non-polarised relays with single armature; with single set of ganged armatures
    • H01H51/06Armature is movable between two limit positions of rest and is moved in one direction due to energisation of an electromagnet and after the electromagnet is de-energised is returned by energy stored during the movement in the first direction, e.g. by using a spring, by using a permanent magnet, by gravity
    • H01H51/065Relays having a pair of normally open contacts rigidly fixed to a magnetic core movable along the axis of a solenoid, e.g. relays for starting automobiles
    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01HELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H1/00Contacts
    • H01H1/58Electric connections to or between contacts; Terminals
    • H01H2001/5877Electric connections to or between contacts; Terminals with provisions for direct mounting on a battery pole
    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01HELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H50/00Details of electromagnetic relays
    • H01H50/02Bases; Casings; Covers
    • H01H50/021Bases; Casings; Covers structurally combining a relay and an electronic component, e.g. varistor, RC circuit
    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01HELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H51/00Electromagnetic relays
    • H01H51/02Non-polarised relays
    • H01H51/04Non-polarised relays with single armature; with single set of ganged armatures
    • H01H51/06Armature is movable between two limit positions of rest and is moved in one direction due to energisation of an electromagnet and after the electromagnet is de-energised is returned by energy stored during the movement in the first direction, e.g. by using a spring, by using a permanent magnet, by gravity
    • H01H51/08Contacts alternately opened and closed by successive cycles of energisation and de-energisation of the electromagnet, e.g. by use of a ratchet
    • H01H51/082Contacts alternately opened and closed by successive cycles of energisation and de-energisation of the electromagnet, e.g. by use of a ratchet using rotating ratchet mechanism
    • H01H51/084Contacts alternately opened and closed by successive cycles of energisation and de-energisation of the electromagnet, e.g. by use of a ratchet using rotating ratchet mechanism with axial ratchet elements

Abstract

The present invention relates to a circuit breaker (1) comprising an input electrical terminal (100), which is intended to be connected to a storage battery and comprises a body connected at one of its ends to a fixed contact element, an output electrical terminal (200), contact means (3) designed to open or close the electrical contact between the input and output electrical terminals, and means for measuring the current passing through the input electrical terminal. According to the invention, the current measuring means comprise, on the one hand, means for measuring the voltage between two measurement points on the input electrical terminal and means for calculating the intensity of the current from said voltage and, on the other hand, an electrical circuit comprising, in series, a switch and a resistor of known value, said electrical circuit being connected on one side to a point of known potential and on the other side to one of said measurement points, which is placed near the contactor element and the potential of which is measured by the voltage measurement means.

Description

CIRCUIT BREAKER BATTERY WITH MEANS OF MEASUREMENT

CURRENT

TECHNICAL FIELD TO WHICH THE INVENTION RELATES The present invention relates generally to the measurement of the intensity of a current supplied from a battery in a circuit breaker. It concerns more particularly a circuit breaker having an electrical input terminal which is intended to be connected to a battery and which comprises a body connected at one of its ends to a fixed contactor element, an electrical output terminal, contact means adapted to close or open the electrical contact between the two electrical terminals of input and output in cooperation with said fixed contactor member, and means for measuring the current flowing in the electric input terminal.

It also relates to a method of measuring an electric current supplied by a battery and via a power input terminal of such a circuit breaker and a method of determining the state of the contact means of such a circuit breaker.

BACKGROUND

Currently, it is already known from document US 2005/0057865 a circuit power control of a motor vehicle, which is connected across the storage battery of the vehicle in order to carry out measurements on this storage battery .

The main drawback of such a circuit is that it is independent of any circuit breaker, so that it generates, relative to the cutout of the vehicle, an additional space and requires clean conditioning means. Furthermore, because of its eccentric position with respect to the circuit breaker, the measurements performed by this circuit are not readily usable by the circuit breaker, unless use between the printed circuit and the circuit breaker means bulky communication, expensive and with limited reliability.

Also known is a type of circuit breaker supra wherein the measuring means comprise an insert Hall effect sensor on the outer face of the electric input terminal. This sensor is typically comprised of a semiconductor chip supplied with a supply current. This plate is sensitive to the presence of a magnetic field perpendicular to it, such a field generating a measurable potential difference between each of its faces. The main drawback of such measuring means is that they have low accuracy and are susceptible to surrounding magnetic fields generated by sources other than the electrical terminal of the circuit breaker input.

OBJECT OF THE INVENTION

To remedy the aforementioned drawbacks of the prior art, the present invention provides more accurate measurement means of the intensity of current through the power input terminal of the circuit breaker.

More particularly, the invention provides a circuit breaker as defined in the introduction, wherein the means for measuring current comprises, firstly, means for measuring the voltage between two points of measurement of the electrical input terminal and means for calculating the amount of current from said voltage, and, secondly, an electrical circuit including in series a switch and a known resistance value, said electrical circuit being connected to side to a known potential point and the other one of said measurement points which is disposed close to the switch element and the potential is measured by means of voltage measurement.

Thus, thanks to the invention, the resistors are generally insensitive to surrounding magnetic fields, it is possible to make an accurate measurement of the electrical potential at two points of measurement of the electrical input terminal. These two measured potentials then allow, by knowing the value of the internal resistance of the electrical input terminal between two points of measurement, calculate the value of the intensity of the current delivered by the battery.

This measurement can also be carried out in open or closed position of the switch so that it is possible to refine the value of the intensity of the current supplied by the storage battery in the circuit breaker. Indeed, taking into account the difference between the potential measured in the open or closed position of the switch is used to calibrate the means for measuring the current. According to a first advantageous characteristic of the circuit breaker according to the invention, the electrical input terminal comprises a hollow body.

Thus, the internal resistance of the material constituting the electrical input terminal between the two measurement points is greater. Or, for a given intensity, when the resistance increases, the voltage to be measured increases. The accuracy of calculation of the intensity of current through the electrical input terminal is thus increased.

Other advantageous and non-limiting features of the circuit breaker according to the invention are the following: - the measuring means comprise two son connected on one side to one of the measuring points and the other to an input an operational amplifier subtracter;

- the switch is a power transistor;

- the known potential point is connected to the electrical ground of the circuit breaker;

- the value of said resistor is at least ten times greater than the value of the internal resistance of the input terminal between the two measuring points;

- the circuit breaker comprises means for measuring an electric potential at a point of the electrical output terminal; - the circuit breaker comprises means for comparing the electrical potentials measured on the electrical input and output; and

- the electrical output terminal comprises a hollow body.

The invention also relates to a method of measuring an electric current supplied by a battery and via an input terminal of such a circuit breaker, comprising the steps of:

- identifying a first potential difference measured by the means for measuring the voltage and a first potential of the measuring point which is connected to the electrical circuit;

- calculating, based on the value of the internal resistance of the electrical input terminal and the first difference of potential measured, the approximate value of the intensity of current through the electrical input terminal;

- closing the switch; - identifying a second difference of potential measured by the means for measuring the voltage and a second potential of the measuring point which is connected to the electrical circuit;

- calculating, based on the variation between the first and second differences of measured potentials, the variation between the first and second potentials at the measuring point, and the approximate value of the calculated intensity of the current, a refined value of intensity of the current through the electrical input terminal; and

- open the switch. According to a first advantageous characteristic of the method according to the invention the temperature is measured of the electrical input terminal and the value of the difference is stored between the approximate value and the refined value of the current intensity through terminal electrical input which is associated with said temperature. Advantageously, determining an internal resistance of a power cable connected between the storage battery and the electrical input terminal and a function of calculating said internal resistance and the variation between the first and second potential differences measured, the value of the internal resistance of the battery. Thus, it is possible to detect accurately this characteristic of the battery which can provide information relating for example to its remaining lifetime or its charging cycles. This information can then optionally be processed by the circuit breaker so that it can more efficiently manage charging and discharging cycles of the battery.

Advantageously, prior to the implementation of these steps, the contact means is opened.

Thus, the intensity of the current through the input terminal is the same as the current through the switch and a known value of resistance. Measuring the intensity of the current supplied by the storage battery is easier since all the current flowing through the electric circuit comprising the series switch and a known value of resistance first passes through the internal resistance of the input electrical terminal (between the two measuring points). The invention also relates to a method of determining the state of the contact means of such a circuit breaker in which it opens the electrical potential values ​​measured by the measuring means on the electrical input and output, and we deduce the open or closed position of the contact means.

Advantageously, we deduce electrical potential values ​​measured by the measuring means on the electrical input and output, the wear state of the contact means.

Thus the method part she pulls that knowing the value of the potential difference between two points each disposed on a electrical input and output, it is possible to first determine if the means contacts are open or closed and, if closed, the electrical losses in the circuit breaker concerning the state of wear of the latter, and in particular that of its contact means. DETAILED DESCRIPTION OF AN EXAMPLE OF EXECUTION

The following description in the accompanying drawings given by way of non-limiting example, explains in what the invention is and how it can be achieved.

In the accompanying drawings: - Figure 1 is a perspective view of the interior of a housing of a circuit breaker according to the invention;

- Figure 2 is a schematic view of a current breaking device at the output of a storage battery;

- Figure 3 is a schematic sectional view of an input electrical terminal according to the invention of the circuit breaker of Figure 1;

- Figure 4 is a schematic sectional view of an alternative embodiment of the electrical terminal of Figure 2 input;

- Figure 5 is a schematic sectional view of attachment means of an electric power cable with a storage battery of the current breaking device of Figure 2;

- Figure 5B is a schematic perspective view of the attachment means of Figure 5;

- Figure 6 is a schematic top view of the circuit breaker of Figure 1; - Figure 7 is a schematic view of part of the electrical circuit of an electronic card of the circuit breaker of Figure 1; and

- Figure 8 is a diagram of opening of the circuit breaker of Figure 1.

In Figure 1, there is shown a circuit breaker 1 according to the invention. This circuit breaker 1 comprises a housing 1A of parallelepiped shape formed by two separate parts intended to be fitted one above the other to define internally a housing 1 B.

On one of its side walls, the housing 1A carries two identical electrical terminals, a power input terminal 100 and an electrical output terminal 200, each having a body 101, 201 of elongate shape extending from the interior of A housing 1 to beyond its side wall.

A first end of each of the bodies 101, 201, one disposed inside the housing 1A, is connected to a switch element 102,

202 fixed. These two electrical terminals 100, 200 are here made of silver plated copper.

The two elements contactors 102, 202 have a square section and a low thickness. They form a flat face facing the interior of the housing

1A. Housing 1B accommodates all circuit breaker of the switchgear 1. One such electrical equipment is contact means 3 adapted to close or open the electrical contact between the two input electrical terminals 100 and output 200 the circuit breaker 1.

These contact means comprise in particular a contact bridge section 3 constituting a beam U whose two legs are oriented towards the interior of the casing 1A and the upper side is facing the planar faces of elements contactors 102, 202 of electrical input terminals 100 and output 200. This contact bridge 3 has a length that allows its upper face to simultaneously contact both planar surfaces of the contactor elements 102, 202.

The contact bridge 3 also presents a central opening allowing it to be secured to a movable shaft 2A engaged in this opening.

This mobile shaft 2A has at mid-height a flange 4 and one of its ends a threaded portion. A compression spring 5 is engaged on said shaft so as to bear against the collar 4. The contact bridge 3 is in turn positioned against the compression spring 5. A nut 6 is screwed onto the threaded portion of the shaft mobile 2A so as to maintain the contact bridge 3 against the compression spring 5. the movable shaft 2A is adapted to translate between two stable positions.

In a first stable position, the contact bridge 3 is disposed remote from the contactor elements 102, 202, and in a second stable position, the contact bridge 3 is in abutment against the contactor elements. The movable shaft 2A is preferably made of non-magnetic material. A bistable driver device 2 of cylindrical shape is connected to the movable shaft 2A and is adapted to move in translation between its first and second stable positions.

1A housing also comprises an internal electronic circuit 10 for controlling the bistable operating device 2. This electronic circuit 10 comprises in particular a microprocessor.

All electrical equipment contained in the housing 1A thus allows to open and close the electrical contact of the electrical circuit to which is connected the circuit breaker 1.

As shown particularly in Figure 2, this circuit breaker 1 is used to electrically isolate a battery of accumulators 300.

More specifically, the second end of the electrical input terminal 100 of the circuit breaker 1 is connected via a power cable 150 to the positive terminal of the secondary battery 300 whose negative terminal is connected to an electrical ground. The circuit breaker 1 and the secondary battery 300 are generally disposed in a safe battery 301 attached to the frame 600 of a motor vehicle which forms the electrical ground.

The second end of the electrical output terminal 200 of the circuit breaker 1 is in turn connected by two separate electric circuits, on the one hand, to a suitable generator 500, when rotated by the main motor (not shown) of said vehicle, to produce an electric current for charging the battery of accumulators 300, and, secondly, an electric motor 400 adapted to rotate the main motor of the vehicle to start. The main engine can eg be an internal combustion engine. As shown in Figure 3, according to an advantageous characteristic of the circuit breaker 1 according to the invention, for its mechanical and electrical connection to the power cable 150, the body 101 of the electrical input terminal

100 is hollow, here on the whole of its length, and form the side of its second end intended to be connected to said cable, a housing 103 opening intended to receive a stripped portion 151 of the cable.

The housing 103 is defined within a tubular wall 104 of the body

101 having a thickness of about 2 millimeters. The inner diameter of the tubular wall 104 of the body 101 corresponds to the outer diameter of the stripped portion of the cable and is generally between 5 and 10 millimeters, it is here equal to 6 millimeters.

This tubular wall 104 is due to its small thickness, adapted to be plastically deformed locally so that, once the stripped portion 151 of the power cable 150 engaged in the housing of the electrical input terminal 100, it is possible to crimp the power cable 150 with the terminal so that they form an inseparable monobloc assembly after crimping.

Advantageously, as shown in Figure 3, the housing 103 opens to the outside of the body 101 of the electrical input terminal 100 adjacent its first end by a side hole 107 with an axis perpendicular to the axis of said terminal and the diameter of approximately 1 millimeter. This side port 107 allows the passage of an electric wire 111. A seal (not shown) can be arranged in this side port 107 so as to prevent water particles from entering the electrical terminal of inlet 100 through this opening. The body 101 of the electrical input terminal 100 further comprises two peripheral grooves 108 laterally reception of an electric wire 113, 114. These two circumferential grooves 108 are disposed close to the switch element 102. They exhibit shallow depth of about 3 millimeters, and allow to laterally maintain an electric wire to the crimp optionally in the groove to fasten it there.

For its fastening to the casing 1A of the circuit breaker 1, as shown more particularly in Figure 3, the body 101 of the electrical input terminal 100 carries on the outer face of its tubular wall 104 with a thread 105 adjacent to the element switch 102 intended to receive a fastening nut (not shown). The electrical input terminal 100 is inserted into an opening in the side wall of the housing 1A of the circuit breaker 1 until the switch element 102 is applied to one side of this side wall. The fastening nut is then screwed onto the thread 105 until it rests against the other face of this side wall. Thus, this side wall is sandwiched between the fastening nut and the switch element 102 so that the electrical input terminal 100 and the housing 1A form a rigid assembly disassembled.

According to a first not illustrated variant of the electrical input terminal, the body of the electrical input terminal may have a peripheral ring disposed at a distance from the near contactor element which then extends the thread. Thus, the sidewall of the housing, for fixing the terminal, is sandwiched between the fastening nut and the peripheral ring so that the switch element is arranged at a distance from the sidewall of the housing of the cutter circuit. In a second variant illustrated more particularly in FIG

4, for its fastening to the side wall 1A of the housing of the circuit breaker, the body 101 of the electrical input terminal 100 externally carries a peripheral ring 106 adapted to be crimped in the lateral wall of the housing 1A by thermodéformation this wall . In this second variant, the switch element 102 may also be disposed away from the side wall of the housing 1A of the circuit breaker 1.

In these first and second variants, the circumferential grooves 108 and the side port 107 of the electrical input terminal 100 are, when the latter is secured to the housing 1A, disposed within the housing 1 A. Thus, according to configuration of the electrical input terminal and in particular its fastening means, the side port 107 and the peripheral grooves 108 may be arranged, when the electrical input terminal 100 is secured to the housing 1A of the circuit breaker 1, either inside the housing 1A, or at its side wall. In the latter case, as shown more particularly in Figure 3, the side wall of the casing 1A can be pierced with oblique channels 112 allow the passage of electric son 111, 113, 114 into the casing 1A of the circuit breaker 1 in opening on one side, at the level of the orifice 107 or peripheral grooves 108, and, on the other, inside the housing 1A. Anyway, the method of attaching the power cable 150 is identical to that described above and is achieved by crimping one end of the cable into the housing 103 of the electrical input terminal 100. advantageously, as shown in figures 5 and 5B, the other end of power cable 150 includes a second exposed portion 152 attached by attachment means to the positive terminal 301 of the secondary battery 300. These means attachment constitute a hooded terminal 160 having a cylindrical base 162 provided on its lateral surface a lug 161 adapted to be crimped onto the second exposed portion 152 of the power cable 150.

The cylindrical base 162 further includes a cylindrical inner housing 163 whose axis coincides with the axis of the cylindrical pedestal 162 and opening on one end of this base. The inner housing 163 has a diameter and a height substantially equal to the diameter and the height of the positive terminal 301 of the battery 300 accumulators.

The cylindrical base 162 is made of a conductive material such as steel but has internally a non-conductive portion 164 arranged on the periphery of the housing 163, the open end of the housing 163 to near the bottom of this recess. Thus, the positive terminal 301 of the battery of accumulators 300, to be electrically connected to the electrical power cable 150 must be inserted to the bottom of housing 163 of the terminal 160. The connection hooded other electric cables for supplying power to other electrical devices is impossible to the extent that their fastening means surélèveraient hooded terminal 160 with respect to the positive terminal 301 of the battery of accumulators 300, which prevents electrical contact between the positive terminal 301 and the hooded terminal 160. These electrical devices are therefore all connected downstream of the circuit breaker 1. the entirety of the current supplied by the storage battery 300 thus passes through the cutout before being transmitted to electrical appliances, which not only makes it possible to make accurate measurements of the intensity of said current at the electric terminal of 100 e of the circuit breaker 1, but also makes it possible during a short circuit, to protect the entire electric apparatus by opening the contact means 3 of the circuit breaker 1.

For fixing the hooded terminal 160 to the positive terminal 301 of the battery of accumulators 300, the cylindrical pedestal 162 includes a transverse groove 165 extending over its entire height, from its central axis to its outer wall. In addition, the cylindrical pedestal 162 is pierced orthogonally to its transversal groove 165 of a bore 166 which is threaded on one side of the groove 165. Thus, when a screw is inserted and screwed in the bore 166, the two faces vis-à-vis the groove 165 move toward one another so that the inner diameter of the housing 163 decreases. Thus, the positive terminal 301 of the secondary battery 300 is clamped and secured to the terminal 160 hooded.

Advantageously, the whole current breaker device at the output of the battery of accumulators 300 that includes said battery, the power supply cable 150 and the circuit breaker 1 provided with the electrical input terminal 100 further comprises means for measuring the temperature of the power supply cable 150.

These measuring means include in particular a temperature sensor 110 inserted into the stripped portion of the power supply cable 150 and crimped in the same time and with the power cable 150 to ensure good thermal contact between the probe and the cable. This temperature probe 110 is connected to the electronic board 10 of the circuit breaker 1 by means of an electrical wire 111 which runs in the housing 103 of the electrical input terminal 100 and exits through the side port 107 practiced near the switch element 102.

Such a temperature sensor 110 may be comprised of a NTC-type resistive sensor or CPT comprising two son in the same sheath, of which a bare wire crimped with the power cable, and another optionally insulated wire connected to the board electronic circuit breaker. Alternatively, the wire 111 may be coaxial with a central portion for measuring the temperature and an outer portion for measuring the electric potential of the second exposed portion 152 of the power cable 150. Also advantageously, the electrical terminal entry 100 comprises means for measuring the voltage between two measuring points which correspond here to the two peripheral grooves 108.

These means for measuring the voltage comprise two electric son 113, 114 each having an end wound around the power input terminal 100, at the bottom of one of the peripheral grooves 108, and another end connected to the electronic card 10 of the circuit breaker 1.

These electrical son are set in said peripheral grooves 108 and may optionally, like the electric wire 111 that connects the temperature sensor 110 to the electronic card 10, enter inside the housing 1A via oblique channels 112.

Alternatively, to simplify the fastening of electric son 113, 114, the electric wire 114 which measures a first electrical potential to the electrical input terminal 100 may be replaced by the electric wire 111 if it is coaxial, and the wire 113 electric measuring a second electrical potential may be replaced by a wire connected to a terminal maintained on the electrical input terminal 100 between the switch element 102 and the housing 1A of the circuit breaker 1.

Anyway, these electric son 113, 114 measured independently of one another, an electrical potential U1, U2 into two distinct points of measurement. The potential difference measured between the two circumferential grooves 108 determines the value of the voltage between these two grooves. This potential difference is non-zero effect to the extent that the electrical input terminal 100 has an internal resistance RO between the two peripheral grooves 108.

As shown more particularly in Figures 6 and 7, the circuit breaker 1 comprises means for measuring the intensity of the current supplied by the storage battery 300 through the electrical terminal 100 to input.

These measuring means comprise means for measuring the voltage between the two circumferential grooves 108 of the electrical input terminal 100, and means for calculating the current intensity from said measured voltage.

These calculation means comprise an operational amplifier subtracter 301 each of whose two inputs is connected to one of two electrical son 113, 114. In known manner, the subtracter 301 operational amplifier comprises an operational amplifier 302 supplied for its operation in current and provided with two input terminals and an output terminal.

The input terminals are connected to electrical son 113, 114 via resistors 303, 304 of equal value. The electric wire connected to input terminal 114 is further connected to electrical ground via a resistor 305. Furthermore, the electric wire connected to input terminal 113 is connected to the output terminal of the the operational amplifier 302 via a resistor 306 of value equal to that of the resistor 305 connected to ground.

The ratio between the value of this resistor 305 and the resistance 303 connected to the electric wire 113 determines the gain K of the operational amplifier subtracter 301. Thus, the U3 potential of the output of the operational amplifier subtracter 301 corresponds to the product the gain K of the operational amplifier subtractor 301 and the difference of potential measured between the two electrical son 113, 114 according to the following formula:

U3 = K. (U2-U1), K being the gain of the operational amplifier subtracter 301, U1 and U2 being respectively the potentials of the measuring son 113, 114, and U3 being the potential of the output terminal of the operational amplifier subtractor 301.

This output terminal is in the circuit board 10 of the circuit breaker 1, connected to an analog digital converter 310 which digitizes the U3 potential measured at the output of the operational amplifier subtracter 301 so that it can be operated by the microprocessor of the electronic board 10. the microprocessor can then calculate the value of this intensity by performing the following calculation:

I == U3: (k.R0), I being the intensity value of the current through the electrical input terminal 100 and RO is the internal resistance of said power input terminal 100 between the two circumferential grooves 108 . These measuring means are adapted to measure very low values ​​of tension in the extent that the gain K of the operational amplifier subtracter 301 may have an important value. Moreover, they are also suitable for measuring low intensities important since the power input terminal being hollow, it has a reduced section which increases the internal resistance which becomes more easily measurable.

Advantageously, the means for measuring the current intensity further includes an electrical circuit 320 of calibrating the channel for measuring the current intensity passing through the electrical input terminal 100. The electrical circuit 320 is in effect useful insofar as, on the one hand, the operational amplifier subtractor 301 is not perfect so that the U3 potential measured on its output has an inherent error in the operation of the operational amplifier 302, and, hand, it may appear variations in the value of the internal resistance RO of the electrical input terminal 100 between the two peripheral grooves 108. in fact, temperature variations and imprecision in the positioning of electric son 113, 114 can varying substantially the value of this internal resistance RO.

This electric circuit 320 comprises a series switch 321 and a resistor 322 of known value; it is connected on the one hand, to one input of the operational amplifier subtracter 301, the electric wire 113 in which the electrical potential is measured, and, on the other, to the electrical ground (identical to that on which is connected the negative terminal of the battery 300 accumulators). The switch 321 here is an electrical transistor.

The resistor 322 has a value of 10 ohms which advantageously is at least ten times greater than the value of the internal resistance RO of the electrical input terminal 100 between the two peripheral grooves 108. The resistor 322 has a lower thermal sensitivity 0.005% per degree so that the temperature differences have little influence on the measurement result.

The method of measuring an accurate value of the current intensity includes various stages. During a first step, the switch 321 being open, the processor calculates using the formulas previously mentioned an approximate value of the intensity of current through the electrical input terminal 100. It is also observed a first potential of the electric wire 113. Then, during a second step, it controls the closing of switch 321. in a third step, it calculates again the amount of current passing between the two circumferential grooves 108 of the electric input terminal. Part of the current flowing through the electric circuit 320, the result of the calculation is different. It also notes a second potential of the electric wire 113. Finally, in a fourth and final step, knowing the exact value of the resistance 322 of the electric circuit 320, it compares the two calculated intensities and the difference between the two potentials measured on the electric wire 113, and determines a refined value of the intensity of current through the electrical input terminal.

So that the current variations due to variations in power requirements of the electrical equipment of the vehicle do not distort the calculation, this closing of the switch 321 may be performed regularly, for example every 50 milliseconds, such that the conditions power between the first and the third step of the method are substantially identical. Another method to ensure that calculations are not distorted is to open the contact means 3 before performing the above measurement steps.

The electronic card 10 then keeps in memory in the storage means, for a given temperature measured by the temperature sensor 110, the correction value of the current intensity.

Thus, thereafter, when the temperature measured by the temperature sensor 110 has already been encountered, the electronic card 10 can be determined by a simple calculation the refined value of the current intensity as a function, firstly, of approximate value of the intensity of the current calculated by the subtractor operational amplifier 301, and, on the other hand, the correction value stored by the storing means. The use of the switch 321 is therefore reduced to the case where the temperature has not yet been met. The calibration of the channel for measuring the intensity of current through the electrical input terminal 100 can then, thanks to these storage means, to be implemented periodically and not continuously. According to an advantageous characteristic of the circuit breaker 1, the electrical output terminal 200, identical to the electrical input terminal 100, carries in one of its circumferential grooves an electrical wire 213 which, using a suitable device 330 such as a voltmeter connected to a digital analog converter, measuring an electrical potential at that point of the terminal. This electrical lead 213 is connected to the electronic board 10 which includes means for comparing between a potential measured on the electrical input terminal 100 and the potential measured on the power output terminal 200. These comparison means, depending on result of this comparison can deduce, firstly, if the contact bridge 3 is in the open or closed position, and, on the other hand, when the contact bridge 3 is in the closed position, the state of wear contact means. Thus, if a significant potential difference characteristic of a premature wear of the contact means is detected, the circuit breaker may inform the driver of the vehicle, for example via a light emitting diode disposed on the dashboard of the vehicle. Similarly, the comparison means are adapted to detect micro-cuts of the current between the two input electrical terminals 100 and outlet 200, said micro power being characteristic of a bad fixation of the power cable 150 of the battery accumulators 300 or on the electrical input terminal 100. If it detects such micro power, it can also notify the driver of the vehicle.

Advantageously, the electronic circuit 10 also includes means for calculating the internal resistance of the secondary battery 300. These calculation means are installed in the microprocessor of the main switch 1; they are adapted to deduce on the one hand, of the variation, when the switch opens and closes, the electric potential measured on a electric son 113, 114, and on the other hand, the value of the internal resistance of the power supply cable 150, the value of the internal resistance of the secondary battery 300. the value and increasing the internal resistance indicating the remaining life of the storage battery 300 connected to the cutting -Circuit 1, the electronic circuit 10 may also provide the driver of the vehicle an indication of end of life of the battery of accumulators 300.

According to an advantageous characteristic of the invention, as more particularly shown in the diagram of Figure 8, the electronic circuit 10 comprises means for determining at least one value of an electric current to the associated parameter passing through the circuit breaker 1 in operation.

These determination means comprises means for measuring at least one value of a quantity associated with said parameter. These measuring means may comprise either all the means for measuring the current through the electrical input terminal 100 of the circuit breaker 1, or only the means for measuring the voltage between the two circumferential grooves 108 of the terminal. Said value of the quantity may be a voltage, an electric potential or a current.

determining means also comprise calculating means which reads the value of the quantity measured by the measuring means to determine the parameter value associated with said magnitude. This parameter is chosen to be characteristic of a short circuit. This setting may for example be an intensity, a voltage drop rate, or a voltage drop rate.

The electronic board 10 also includes means for storing at least one threshold value of at least one parameter associated with the electrical current through the circuit breaker. These threshold values ​​are established during manufacture of the electronic card 10 and does not vary. They relate here the maximum values ​​that the parameters determined by the determination means must not exceed.

Threshold values ​​can be, for example, when the current is supplied from the storage battery 300 to power the electric motor 400 to start the main engine of the vehicle, of 2000 amps for 1 second and 1500 Amps for 5 seconds, 1000 amperes for 15 seconds, 500 amps for 60 seconds, and 0.1 volts per second.

They can have different values ​​when the power is delivered by the alternator 500 to recharge the storage battery 300. They can then be of 200 amps for 1 second.

These values ​​are variable depending on the battery type which is for the circuit breaker 1.

The electronic board 10 also includes means for comparing the values ​​determined by the determining means and limit values ​​associated with them. Here, these means compares in real time not only the value of the voltage drop rate with the threshold value associated with it, but also the intensity of the current flowing in the electrical input terminal 100 with the different threshold values associated with it. Thus, as soon as at least one of the values ​​of a parameter determined by the determination means exceeds the threshold value associated with it, the comparison means of the electronic card 10 provide an information processing means capable of converting the information in an opening control order of the contact bridge 3.

Therefore, when a short circuit is detected by the circuit breaker 1, the latter quickly cutting the electrical contact at the outlet of the secondary battery 300 so as to electrically isolate to protect the storage battery 300 and electrical equipment it powers or to protect the electrical alternator 500 if the short circuit from the battery of accumulators 300.

Advantageously, the circuit breaker 1 comprises inside the housing 1A of the shock detecting means and inclination sensing means.

These detection means are sensors which are electrically connected to the electronic board 10 and which send an electric signal when they detect a shock greater eg 10 G or an inclination of the upper housing for example to 15 degrees. Such a shock or such an inclination in effect means that the vehicle provided with the circuit breaker 1 has suffered an accident, thereby increasing the probability that a short-circuit appears. The electronic card 10 is in this case adapted to lower values ​​of the set of threshold values ​​(e.g. 200 amps for one second regardless of the direction of flow) so as to more effectively prevent the occurrence of short circuits .

The present invention is not limited to the embodiments described and shown, the art can apply any variant within its spirit.

Claims

1. Circuit breaker (1) having an electrical input terminal (100) which is intended to be connected to a storage battery (300) and which comprises a body (101) connected at one of its ends to an element switch (102) fixed, an electrical output terminal (200) and contact means (3) adapted to close or open the electrical contact between the two electrical input terminals (100) and outlet (200) cooperating with said switch element (102), and current measuring means (113, 114, 301, 320) passing through the electrical input terminal (100), characterized in that the means for measuring current comprise of First, the voltage measuring means (113, 114, 301) between two measuring points (108) of the electrical input terminal (100) and means for calculating the current intensity from said voltage, and, secondly, an electrical circuit (320) comprising in series a switch (321) and a resistor (322) of known value, said electrical circuit (320) being connected on one side to a known potential point and the other one of said measuring points (108) which is arranged close to the switch element (102) and whose potential is measured by means for measuring the voltage (113, 114, 301).
2. Circuit breaker (1) according to claim 1, characterized in that the electrical input terminal (100) comprises a body (101) hollow.
3. A circuit breaker (1) according to one of claims 1 and 2, characterized in that the voltage measuring means comprise two electric son (113, 114) connected from one side to one of the measuring points ( 108), and on the other to one input of a subtractor operational amplifier (301).
4. Circuit breaker (1) according to one of claims 1 to 3, characterized in that the switch (321) is a power transistor.
5. Circuit breaker (1) according to one of claims 1 to 4, characterized in that the known potential point is connected to the electrical ground of the circuit breaker
(1).
6. Circuit breaker (1) according to one of claims 1 to 5, characterized in that the value of said resistor (322) is at least ten times greater than the value of the internal resistance (RO) of the electrical terminal input (100) between said two measuring points (108).
7. Circuit breaker (1) according to one of claims 1 to 6, characterized in that it comprises means for measuring (330) an electric potential at a point of the electrical output terminal (200).
8. Circuit breaker (1) according to claim 7, characterized in that it comprises means for comparing the electrical potentials measured on the electrical input terminals (100) and outlet (200).
9. Circuit breaker (1) according to one of Claims 7 and 8, characterized in that the electrical output terminal (200) comprises a hollow body.
10. A method of measuring an electric current supplied from a battery (300) and passing through an electrical input terminal (100) of a circuit breaker (1) according to one of claims 1 to 9 characterized in that it comprises the steps of:
- identifying a first potential difference measured by the means for measuring the voltage (113, 114, 301) and a first potential of the measuring point (108) on which is connected the electrical circuit (320);
- calculating, based on the value of the internal resistance (RO) from the power input terminal (100) between the two measuring points (108) and the first difference of potential measured, the approximate value of the intensity (I) of the current through the electrical input terminal (100); - closing the switch (321);
- identifying a second difference of potential measured by the measuring means of the voltage (113, 114, 301) and a second potential of the measuring point (108) on which is connected the electrical circuit (320);
- calculating, based on the variation between the first and second differences of measured potentials, the variation between the first and second potential of the measuring point (108) and the approximate value of the intensity (I) of the calculated current a refined value of the intensity (I) of the current through the electrical input terminal (100); and
- open the switch (321).
11. Measuring method according to claims 10, characterized by measuring the temperature of the electrical input terminal (100) and storing a value of the difference between the approximate value and the refined value of the intensity ( I) of the current through the electrical input terminal (100) which is associated with said temperature.
12. Measuring method according to one of claims 10 and 11, characterized by determining an internal resistance of an electrical supply cable (150) connected between the storage battery (300) and the electrical terminal input (100) and is calculated according to said internal resistance and the variation between the first and second differences of measured potentials, the value of the internal resistance of the storage battery (300).
13. Measuring method according to one of claims 10 to 12, characterized in that, prior to the implementation of said steps layout, the contact means is opened (3).
14. Method of determining the state of contact means (3) of a circuit breaker (1) according to one of claims 7 to 9, characterized in that opens the electrical potential values ​​measured by measuring means (113, 114, 301) on the electrical input terminals (100) and outlet (200), and is deduced in the open or closed position of the contact means (3).
15. Method of determination according to claim 14, characterized in that deduced from the electrical potential values ​​measured by the measuring means (113, 114, 301) on the electrical input terminals (100) and outlet (200 ), the state of wear of the contact means (3).
PCT/FR2007/000025 2006-01-10 2007-01-09 Battery circuit breaker comprising current-measuring means WO2007080304A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
FR0600196A FR2896085B1 (en) 2006-01-10 2006-01-10 battery circuit breaker comprising current measuring means passing through its input terminal and measurement methods of the current and the state of the circuit breaker
FR0600196 2006-01-10

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP20070717743 EP1971995A1 (en) 2006-01-10 2007-01-09 Battery circuit breaker comprising current-measuring means

Publications (1)

Publication Number Publication Date
WO2007080304A1 true true WO2007080304A1 (en) 2007-07-19

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PCT/FR2007/000025 WO2007080304A1 (en) 2006-01-10 2007-01-09 Battery circuit breaker comprising current-measuring means

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EP (1) EP1971995A1 (en)
FR (1) FR2896085B1 (en)
WO (1) WO2007080304A1 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2947111B1 (en) * 2009-06-22 2013-03-01 Peugeot Citroen Automobiles Sa Electrical circuit
EP2568296A1 (en) * 2011-09-12 2013-03-13 Eaton Industries GmbH Measuring resistance with short circuit protection

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0206488A1 (en) * 1985-05-14 1986-12-30 Salplex Limited Method and apparatus for measuring electric current
GB2259783A (en) * 1991-09-19 1993-03-24 Ampy Automation Digilog Four-terminal current measuring devices
EP0873908A2 (en) * 1997-04-25 1998-10-28 Niles Parts Co., Ltd. Current detecting resistor and car-borne unit
DE10041879A1 (en) * 2000-08-25 2002-03-14 Hella Kg Hueck & Co Load current measurement method in on-board power supply of vehicle, involves connecting fuse element parallel to load, where fuse element acts as shunt resistor
US20050057865A1 (en) * 2003-07-25 2005-03-17 Midtronics, Inc. Shunt connection to a PCB of an energy management system employed in an automotive vehicle
FR2865313A1 (en) * 2004-01-15 2005-07-22 Diamecans Bistable operating device for circuit breaker, has core mounted movably on movable shaft and comprising axial blind housing extending on part of length of core, where one end of shaft engages in housing

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0206488A1 (en) * 1985-05-14 1986-12-30 Salplex Limited Method and apparatus for measuring electric current
GB2259783A (en) * 1991-09-19 1993-03-24 Ampy Automation Digilog Four-terminal current measuring devices
EP0873908A2 (en) * 1997-04-25 1998-10-28 Niles Parts Co., Ltd. Current detecting resistor and car-borne unit
DE10041879A1 (en) * 2000-08-25 2002-03-14 Hella Kg Hueck & Co Load current measurement method in on-board power supply of vehicle, involves connecting fuse element parallel to load, where fuse element acts as shunt resistor
US20050057865A1 (en) * 2003-07-25 2005-03-17 Midtronics, Inc. Shunt connection to a PCB of an energy management system employed in an automotive vehicle
FR2865313A1 (en) * 2004-01-15 2005-07-22 Diamecans Bistable operating device for circuit breaker, has core mounted movably on movable shaft and comprising axial blind housing extending on part of length of core, where one end of shaft engages in housing

Also Published As

Publication number Publication date Type
FR2896085A1 (en) 2007-07-13 application
FR2896085B1 (en) 2008-03-14 grant
EP1971995A1 (en) 2008-09-24 application

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