FR3039006A1 - DEVICE FOR MANAGING AN ASSEMBLY OF STORAGE CELLS OR GENERATING ELECTRICAL ENERGY - Google Patents

Abstract

The invention relates to an assembly (100) comprising: a plurality of cells (C1, C2, C3, C4) for storing and / or producing electrical energy connected in series and / or in parallel between first (V-) and second (V +) terminals for providing a voltage; and a management device (101) comprising a plurality of measurement units (MU1, MU2, MU3, MU4) respectively associated with the different cells of the assembly, each measurement unit (MUi) comprising first (Din) and second (Dout) terminals and a measuring circuit (MES) adapted to transmit on the second terminal (Dout) a change of state of a signal applied to the first terminal (Din), with a delay depending on a physical parameter of the cell associated with it, in which the units of measurement (MU1, MU2, MU3, MU4) are connected in a chain so that each unit of measurement (MUi), except for the first of the chain, has its first terminal (Din) connected to the second terminal (Dout) of the previous rank measurement unit in the chain.

Description

DEVICE FOR MANAGING AN ASSEMBLY OF STORAGE CELLS OR GENERATING ELECTRICAL ENERGY

Field

The present application relates to the field of series and / or parallel assemblies of storage cells or electric energy production such as electric batteries, fuel cells, photovoltaic panels, etc. It relates more particularly to an assembly comprising a management device for monitoring one or more physical parameters of each of the cells of the assembly.

Presentation of the prior art

An electric battery is a grouping of several energy storage cells (batteries, accumulators, etc.) connected in series and / or in parallel between two nodes or terminals for supplying a DC voltage. An electric battery may be provided with a management device comprising, associated with each cell, one or more sensors adapted to measure one or more physical parameters of the cell, for example its temperature or its voltage. A problem that arises is that of reading the output values of the sensors of the management device, and the transmission of read values to a centralized control unit.

To perform this reading, it is possible to provide a wired connection connecting each sensor to the control unit. The number of cables of the management device is then high, which causes a significant increase in the cost price of the battery. In addition, when the cells of the battery are connected in series and each sensor has the voltage of the cell to which it is associated, the output values of the different sensors can be referenced with respect to distinct potentials. , sometimes relatively distant. It is then necessary to provide galvanic isolation devices between the outputs of the sensors and the control unit, which further increases the cost price of the battery. Other communication systems have been proposed such as wireless communication systems, powerline communication systems using the power path of the battery to transmit the output values of the sensors, or resonator systems of the type described in patent applications FR2976407 and US2014159735. These systems have various disadvantages, including those of being complex and expensive. summary

Thus, an embodiment provides an assembly comprising: a plurality of storage cells and / or electrical energy production connected in series and / or in parallel between first and second terminals for supplying a voltage; and a management device comprising a plurality of measurement units associated respectively with the different cells of the assembly, each measurement unit comprising first and second terminals and a measuring circuit adapted to transmit on the second terminal a change of state. of a signal applied to the first terminal, with a delay depending on a physical parameter of the cell associated with it, in which the units of measurement are connected in a chain so that each unit of measurement, with the exception of the first of the chain, has its first terminal connected to the second terminal of the previous rank measurement unit in the chain.

According to one embodiment, each measurement unit further comprises third and fourth terminals and a propagation circuit adapted to transmit without delay on the fourth terminal a change of state of a signal applied to the third terminal or to the second terminal. thick headed.

According to one embodiment, in each measurement unit, the propagation circuit is adapted to supply on the fourth terminal an output signal corresponding to an EXCLUSIVE OR of the signals applied to the third and second terminals.

According to one embodiment, in each measurement unit, the propagation circuit is adapted to supply on the fourth terminal an output signal corresponding to a NAND and signals applied to the third and second terminals.

According to one embodiment, in each measurement unit, the propagation circuit is adapted to generate a pulse on the fourth terminal during a change of state of the signal applied to the third terminal or to the second terminal.

According to one embodiment, each measurement unit, except for the first of the chain, has its third terminal connected to the fourth terminal of the previous rank measurement unit in the chain.

According to one embodiment, the management device further comprises a control circuit connected to the first and third terminals of the first measurement unit of the chain, and to the fourth terminal of the last measurement unit of the chain.

According to one embodiment, in each measurement unit, the measuring circuit comprises a resistor and a capacitor forming an RC circuit, at least one resetting switch of the RC circuit whose control gate is connected to the first terminal of the circuit. unit of measurement, and a comparator whose input is connected to an electrode of the capacitor and whose output is connected to the second terminal of the measurement unit.

According to one embodiment, the assembly comprises at least one connection capacity between the first terminal of the measurement unit and the control gate of the switch.

According to one embodiment, in each measurement unit, the comparator is of the open-drain or open-collector type.

According to one embodiment: each measurement unit is a printed circuit board, the first and third terminals of the measurement unit being disposed on a first face of the printed circuit board, and the second and fourth terminals of the printed circuit board; unit of measurement being arranged on a second face of the printed circuit board, respectively facing the first and third terminals; and the units of measure are stacked so that each unit of measurement, except the first one of the stack, has its first and third terminals in contact with the second and fourth terminals of the rank measuring unit, respectively. previous in the stack.

Brief description of the drawings

These characteristics and their advantages, as well as others, will be described in detail in the following description of particular embodiments made in a non-limiting manner in relation to the appended figures among which: FIG. 1 is an electrical diagram of an example an embodiment of an electric battery equipped with a management device; FIG. 2 shows in greater detail an exemplary embodiment of a measurement unit of the management device of FIG. 1; Figure 3 is a timing diagram illustrating the operation of the management device of Figure 1 according to an exemplary embodiment; Figure 4 is a timing diagram illustrating the operation of the management device of Figure 1 according to an alternative embodiment; Figures 5 to 13 detail various embodiments of the measurement unit of Figure 2; and Figures 14 and 15 schematically illustrate examples of an embodiment of a fuel cell equipped with a management device.

detailed description

The same elements have been designated with the same references in the various figures. For the sake of clarity, only the elements that are useful for understanding the described embodiments have been shown and are detailed. In particular, the exploitation made of the measurements made by the sensors of the management devices described is not detailed, the described embodiments being compatible with the usual uses that can be made of such measurements. Unless otherwise specified, the terms "approximately", "substantially", and "of the order of" mean within 10%, preferably within 5%. In the present description, the term "connected" is used to denote a direct electrical connection, without intermediate electronic component, for example by means of one or more conductive tracks, and the term "coupled" or the term "connected", for designate either a direct electrical connection (meaning "connected") or a connection via one or more intermediate components (resistor, capacitor, etc.).

FIG. 1 is a circuit diagram of an example of an embodiment of an electric battery 100 provided with a management device 101.

The battery 100 comprises a plurality of energy storage cells, four cells C1, C2, C3 and C4 in the example shown, connected in series between a positive terminal V + and a negative terminal V- for supplying a DC voltage. . The cells C1, C2, C3 and C4 are for example identical or similar. Of course, the described embodiments apply regardless of the number of cells in the battery.

The battery 100 of FIG. 1 comprises a management device 101 comprising, associated with each cell of the battery, a unit of measurement of a physical parameter of the cell. Thus, in the example shown, the management device 101 comprises four measurement units MU1, MU2, MU3, MU4, respectively associated with the cells C1, C2, C3 and C4.

The units of measurement MUi, with i integer ranging from 1 to 4 in this example, are for example identical or similar. Each measurement unit MUi comprises a low-power supply potential terminal, and a high-power supply voltage terminal +. In the example shown, each measurement unit MUi is fed by the cell Ci with which it is associated. Thus, each measurement unit MUi has its low supply terminals val- and high-val + respectively connected to the negative terminal and the positive terminal of the cell Ci. However, the described embodiments are not limited to this particular case. Alternatively, each measurement unit MUi may require a supply voltage greater than the voltage of a cell. In this case, the low val- and high-value + supply terminals of a measurement unit MUi can be respectively connected to the negative end and to the positive end of a series association of several cells of the battery.

Each measurement unit MUi further comprises a first input terminal Din, a second input terminal Sin, a first output terminal Dout, and a second output terminal Sout. In this example, the terminals Din, Sin, Dout and Sout are intended to receive or provide binary signals.

FIG. 2 illustrates in greater detail an exemplary embodiment of a measurement unit MUi of the management device 101 of FIG. 1.

In this example, the measurement unit MUi comprises a measurement circuit MES adapted to measure a physical parameter P of the cell Ci, for example its voltage or its temperature. The measuring circuit MES is connected to the terminals Din and Dout of the measuring unit MUi. The MES circuit is adapted, when a rising or falling edge is applied to the Din terminal of the measurement unit MUi, to apply a rising or falling edge to the terminal Dout of the measurement unit with a delay depending on the value of the measured physical parameter. In other words, the MES circuit is adapted to reproduce on the output terminal Dout a change of state of the signal applied to the input terminal Din, with a delay representative of the value of the measured physical parameter. The measurement unit MUi further comprises a propagation circuit PROP connected to its terminals Sin, Dout and Sout. The circuit PROP is adapted, when a rising or falling edge is applied on the terminal Sin or Dout of the measurement unit, to force without delay a change of state of an output signal supplied on the terminal Sout. In other words, the propagating circuit PROP is adapted to provide on the output terminal Sout a signal representative of changes of state of the signals present on the terminals Dout and / or Sin. In the present description, without delay means without delay or with a negligible delay, for example with a delay of less than 10%, and preferably less than 1% of the smallest delay introduced by the MES circuit between the terminals Din and Dout. By way of example, the delay introduced by the circuit MES between the terminals Din and Dout can range from 10 ps to 10 ms depending on the value of the parameter measured, and the delay introduced by the circuit PROP between the terminals Sin and Sout is less at 1 ps and preferably less than 100 ns.

As illustrated in FIG. 1, the units of measurement MUi are connected in a chain by their respective terminals Din, Dout, Sin and Sout, in the following manner.

Each unit of measure MUi except the unit of measure located at a first end of the chain, namely the unit of measure MUI in the example shown, has its terminals Din and Sin respectively connected to the terminals Dout and Sout of the previous rank measurement unit in the chain, namely the unit of measure MUi-1 in the example shown.

The management device 101 further comprises a control unit 103 (CTRL), comprising for example a microprocessor. The control unit 103 is connected to the input terminals Din and Sin of the first measurement unit of the string (the measurement unit MU1 in this example). The control unit 103 is further connected to the output terminals Dout and Sout of the last measurement unit of the chain (the measurement unit MU4 in this example). On the other hand, the control unit 103 is not connected to the terminals Din, Sin, Dout and Sout of the intermediate measurement units of the chain. The control unit 103 is adapted to apply input signals to the terminals Din and Sin of the first measurement unit of the chain, and to read output signals on the terminals Dout and Sout of the last measurement unit chain. In practice, the Din and Sin terminals of the first measurement unit of the chain can be connected. In addition, the connection between the output terminal Dout of the last measurement unit of the chain and the measurement unit 103 is optional.

FIG. 3 is a timing diagram illustrating the operation of the management device of FIG. 1. An exemplary embodiment is considered here in which the signals on the terminals Din and Dout of each measurement unit MUi are initially in a low state, and in FIG. which, when a rising edge is applied to the terminal Din, the measurement circuit MES of the measurement unit high the signal of the terminal Dout after a delay representative of the value of the measured physical parameter. Moreover, in this example, the signals on the terminals Sin and Sout of each measurement unit MUi are initially in the low state, and the propagation circuit PROP implements an EXCLUSIVE OR of the signals present on the terminals Sin and Dout. , the signal on the terminal Sout corresponding to the output signal of the EXCLUSIVE OR. Moreover, in this example, in each measurement unit MUi, the measuring circuit MES is adapted, when a falling edge is applied to its input terminal Din, to reproduce this falling edge without delay on its output terminal Dout. , which allows a quick reset of the device.

The timing diagram of FIG. 3 represents the evolution, as a function of time, of the signals Din (MU1), Din (MU2), Din (MU3) and Din (MU4) respectively applied to the input terminals Din of the measurement units MU1, MU2, MU3 and MU4, the signal Sin (MU1) applied to the input terminal Sin of the unit of measurement MU1, and signals Dout (MU4) and Sout (MU4) provided on the output terminals Dout and Sout of the unit of measurement MU4. At a time t0, the management device 101 is in a so-called reset state, in which the signals on the terminals Din, Sin, Dout and Sout of each of the measurement units are in the low state. At a time t1 subsequent to the instant t0, the signals Din (MU1) and Sin (MU1) are set high by the control unit 103. High setting of the signal Sin (MUl) causes without delay a signal state change on the output terminal Sout of the measurement unit MU1. This state change propagates to the output terminal Sout of the measurement unit MU4 via the propagation circuits PROP of the different measurement units. Thus, as shown in FIG. 3, the signal Sout (MU4) goes high at substantially instant t1. High setting of the signal Din (MUl) also triggers the delay of the measurement circuit MES of the unit of measure MU1. At a time t2 after time t1, the signal on the output terminal Dout of the measurement unit MU1, which corresponds to the signal Din (MU2), goes high. The delay t2-t1 is representative of the value of the physical parameter measured by the measurement circuit MES of the measurement unit MU1. High setting of the Din signal (MU2) causes a signal state change on the output terminal Sout of the measurement unit MU1. This state change propagates to the output terminal Sout of the MU4 measurement unit. Thus, the signal Sout (MU4) goes low substantially at time t2. High setting of the signal Din (MU2) also triggers the delay of the measurement circuit MES of the measurement unit MU2. At a time t3 later than time t2, the signal Din (MU3) goes high. The delay t3-t2 is representative of the value of the physical parameter measured by the measurement unit MU2. High setting of the signal Din (MU3) causes a change of state, substantially at time t3, of the signal Sout (MU4), and further causes the triggering of the delay of the unit of measure MU3. At a time t4 later than time t3, the signal Din (MU4) goes high. The delay t4-t3 is representative of the value of the physical parameter measured by the measurement unit MU3. High setting of the signal Din (MU4) causes a change of state, substantially at time t4, of the signal Sout (MU4), and further causes the triggering of the delay of the measurement unit MU4. At a time t5 later than time t4, the signal Dout (MU4) goes high. The delay t5-t4 is representative of the value of the physical parameter measured by the measurement unit MU4. High setting of the signal Dout (MU4) causes a change of state, substantially at time t5, of the signal Sout (MU4). At a time t6 later than time t5, the device is reset. For this, the signals Din (MUl) and Sin (MUl) are set low, which causes the setting of all the signals on the Din, Sin, Dout and Sout terminals without delay. management system.

Thus, in the management device 101, the measured information is coded in the form of a time sequence provided on the output terminal Sout of the last measurement unit of the string. To go back to the measured values, it is sufficient for the control unit 103 to measure the time elapsed between two successive switches of the signal supplied on the output terminal Sout of the last measurement unit of the string.

The switching of the signal supplied on the output terminal Sout of the last measurement unit of the string, characteristics of the values of the parameters measured by the different units of measurement MUi, occur in the order in which the units of measurement are arranged in chain. Thus, in order to know which measurement unit MU corresponds to a value read in the form of a lapse of time between two successive swings of the signal supplied on the output terminal Sout, it suffices for the control unit 103 to count the number output signal failovers that have occurred since the device was last reset.

An example of operation of the management device in which each measurement circuit MES is adapted to propagate a rising edge of its input Din to its output Dout, with a delay representative of the value of the measured physical parameter, has been described here. Alternatively, similar operation can be implemented with measuring circuits adapted to propagate falling edges. Moreover, the embodiments described are not limited to the above-mentioned example in which the propagation circuit PROP of each measurement unit MUi implements an EXCLUSIVE OR function of the signals present on the terminals Sin and Dout.

FIG. 4 is a timing diagram illustrating the operation of an alternative embodiment of the management device of FIG. 1. An exemplary embodiment is considered here in which the signals on the terminals Din and Dout of each measurement unit MUi are initially a high state, and in which, when a falling edge is applied to the terminal Din, the measurement circuit MES of the measurement unit lowers the signal of the terminal Dout after a delay representative of the value the measured physical parameter. In this example, the signal on the terminal Sin of the first measurement unit MUI is initially in the low state, and the propagation circuit PROP implements a function NAND and the signals present on the terminals Sin and Dout. Moreover, in this example, in each measurement unit MUi, the measurement circuit MES is adapted, when a rising edge is applied to its input terminal Din, to reproduce without delay this rising edge on its output terminal Dout. , which allows a quick reset of the device.

The timing diagram of FIG. 4 represents the evolution, as a function of time, of the Din (MU1), Din (MU2), Din (MU3) and Din (MU4) signals respectively applied to the Din input terminals of the measurement units. MU1, MU2, MU3 and MU4, signals Sin (MU1), Sin (MU2), Sin (MU3) and Sin (MU4) respectively applied to the input terminals Sin of the measurement units MU1, MU2, MU3 and MU4, and signals Dout (MU4) and Sout (MU4) provided on the output terminals Dout and Sout of the measurement unit MU4. At a time t0, the management device 101 is in a so-called reset state, in which the signals on the terminals Din and Dout of each of the measurement units are in the high state, and in which the signal Sin (MUl) is in the low state. Each propagation circuit PROP of the unit of measurement chain implementing a NAND function, the signals Sin (MU2), Sin (MU3), Sin (MU4) and Sout (MU4) are respectively in the high state, in the low state, in the high state, and in the low state. At a time t1 subsequent to the instant t0, the signals Din (MU1) and Sin (MU1) are respectively set low and high by the control unit 103. The setting to the state High signal Sin (MUl) immediately causes a change of state of the signal Sout (MU4), which then goes high. Low setting of the Din signal (MUl) triggers the delay of the measuring circuit MES of the measuring unit MUl. At a time t2 posterior to time t1, the signal on the output terminal Dout of the measurement unit MU1, which corresponds to the signal Din (MU2), goes to the low state. The delay t2-t1 is representative of the value of the physical parameter measured by the measurement circuit MES of the measurement unit MU1. This causes a state change of the signal Sout (MU4), which then goes low, and also triggers the delay of the measurement circuit MES of the measurement unit MU2. At a time t3 later than time t2, the signal Din (MU3) goes low. The delay t3-t2 is representative of the value of the physical parameter measured by the measurement unit MU2. This causes a state change of the signal Sout (MU4), and also triggers the delay of the unit of measurement MU3. At a time t4 later than time t3, the signal Din (MU4) goes low. The delay t4-t3 is representative of the value of the physical parameter measured by the measurement unit MU3. This causes a state change of the signal Sout (MU4), and also triggers the delay of the unit of measurement MU4. At a time t5 later than time t4, the signal Dout (MU4) goes low. The delay t5-t4 is representative of the value of the physical parameter measured by the measurement unit MU4. This causes a state change of the signal Sout (MU4). At a time t6 later than time t5, the device is reset. For this, the signals Din (MUl) and Sin (MUl) are respectively set high and low.

Thus, as in the example of FIG. 3, the measured information is coded in the form of a time sequence provided on the output terminal Sout of the last measurement unit of the string. To go back to the measured values, the control unit 103 may be configured to measure the time elapsed between two successive switches of the signal supplied on the output terminal Sout of the last measurement unit of the string.

It will be noted that in the examples of FIGS. 3 and 4, the propagation circuit PROP implements a logic function making it possible to obtain a signal state change on the Sout terminal when one of the signals of the terminals Dout and Sin changes state. The new state of the signal on the Sout terminal is then maintained until the next reset. As a variant, the state change applied to the terminal Sout when one of the signals of the terminals Dout and Sin changes state, perhaps of impulse type, that is to say that the signal of the Sout terminal only briefly changes state when a state change of one of the Dout and Sin terminals signals, then resumes its default state until the next event. In this case, to go back to the measured values, the control unit 103 may be configured to measure the time elapsed between two successive pulses of the signal supplied on the output terminal Sout of the last measurement unit of the string. Alternatively, the signal provided on the Sout terminal of each measurement unit can be obtained not from the signals available on the Sin and Dout terminals of the measurement unit, but from the signals available on the Sin terminals. and Din of the unit of measurement. In this case, the control unit 103 must scan not only the signal Sout of the last measurement unit, but also the signal Dout of the last measurement unit, in order to be able to determine the value measured by the last unit of measurement. Indeed, in this configuration, the change of state on the terminal Dout of the last measurement unit is not reflected on the terminal Sout of this unit of measure.

FIGS. 5 to 13 detail various embodiments of the measurement unit MUi of FIG. 2.

FIG. 5 is a circuit diagram of an exemplary embodiment of the measurement circuit MES of the measurement unit MU1 of FIG. 2.

In this example, the measurement circuit MES is adapted to propagate a rising edge between the terminal Din and the terminal Dout of the measurement unit with a delay representative of the voltage between its supply terminals val- and val +. Thus, if we consider a management device in which each measurement unit MUi is fed by the cell with which it is associated, each measurement unit MUi is adapted to measure the voltage of the cell with which it is associated.

The measuring circuit MES comprises a voltage comparator CMP whose output is connected to the terminal Dout of the measurement unit. The input of the comparator CMP is connected to a first end of a resistor R, the second end of the resistor R being connected to the high supply terminal val + of the measurement unit via a switch SW1 . The input of the comparator CMP is further connected to a first electrode of a capacitor C, the second electrode of the capacitor C being connected to the low supply terminal of the measuring unit. The measuring circuit MES further comprises a switch SW2 connecting the second end of the resistor R to the second electrode of the capacitor C. The switches SW1 and SW2 are controlled in a complementary manner, by means of the signal applied to the terminal Din of the unit of measure. By way of example, the switches SW1 and SW2 are respectively in the off state and in the on state when the signal Din is in a low state, and are respectively in the on state and in the off state when the Din signal to a high state. The comparator is for example supplied by the supply voltage of the measurement unit. The comparator CMP is adapted to compare its input voltage Vin, namely the voltage across the capacitor C, with a reference voltage VREF (for example an internal reference). When the voltage Vin is lower than the voltage VREF, the output voltage Vout of the comparator (referenced with respect to the terminal val- in this example) is at a low state, for example close to 0 V. When the voltage Vin is higher at the voltage VREF, the output voltage Vout of the comparator is at a high state, for example of the order of the supply voltage of the comparator.

When the switches SW1 and SW2 are respectively in the off state and in the on state (i.e. when the signal on the terminal Din is low in this example), the capacitor C is discharged and the voltage Vin takes a value close to 0 V. The voltage Vout is then in the low state.

When the switches SW1 and SW2 are respectively turned on and off (that is, when the signal Din is high in this example), the capacitor C charges up to at a voltage close to the supply voltage of the measuring unit. The rise time of the voltage Vin to the threshold VREF, that is to say the time elapsing between the control of the switches SW1 and SW2 respectively in the on state and in the off state and the switching of the voltage Vout from the low state to the high state depends on the value of the supply voltage of the measurement unit. If the values of the resistance R and the capacitance C are considered as known, the measurement of this delay (via the output signal supplied on the terminal Sout of the last measurement unit of the chain) makes it possible to go back to the voltage of the cell. Alternatively, the comparator CMP may be a hysteresis comparator to limit the effects of noise and promote a fast and frank transition of the signals on the terminal Dout.

Moreover, instead of measuring the charging time of the capacitor C to the threshold VREF starting from an unloaded state, it is possible to measure the discharge time of the capacitor C to the threshold VREF starting from a state charge. Moreover, the two operating modes (charging and discharging) can be implemented successively.

Thus, the measuring circuit MES of FIG. 5 is compatible with an operation of the type described with reference to FIGS. 1 to 4.

More generally, a circuit of the type of FIG. 5 can be used to measure any physical parameter whose value can be converted into a variation of voltage, current, resistance or capacitance. By way of illustrative example, a circuit of the type described in relation with FIG. 5 can be used to measure a temperature, by replacing the resistor R by a thermistor, that is to say a resistor whose value varies according to of the temperature. In this case, in order to obtain a measurement that is independent of the voltage of the cell, the comparator reference threshold can be set to a value that is a function of the supply voltage of the comparator, for example at half the supply voltage of the comparator. comparator. As a variant, the resistor R may be replaced by any resistive sensor making it possible to transform a variation of a physical parameter into a resistance variation, for example a resistive or piezoresistive strain gauge, a resistive displacement sensor (potentiometer type). , photoresistance, etc. Alternatively, the resistor R can be replaced by a current source delivering a current of variable intensity according to a physical parameter to be measured, for example a photodiode, a current source controlled voltage (which allows performing a voltage measurement), a photocell, a current-driven current source (which makes it possible to measure a current, for example by means of a current mirror or a current transformer), etc. As a variant, the resistor R can be considered as known, and the capacitor C can be replaced by any capacitive sensor making it possible to transform a variation of a physical parameter into a capacitance variation, for example a capacitive accelerometer, a capacitance sensor or a capacitor. capacitive displacement, a capacitive proximity sensor, a variable capacitance whose value depends on its bias voltage (which allows a voltage measurement), etc.

FIG. 6 is an electrical diagram of an alternative embodiment of the measurement circuit MES of FIG. 5. The measuring circuit MES of FIG. 6 differs from that of FIG. 5 in that, in the circuit of FIG. the switch SW2 has been removed, and the resistor R and the capacitor C are connected in parallel between the input of the comparator CMP and the terminal val-. The switch SW1 connects the input of the comparator CMP to the terminal val +.

The operation of the circuit of FIG. 6 is as follows. When the switch SW1 is in the on state, the capacitor C charges at a value close to the supply voltage of the measurement unit. The output voltage Vout of the comparator CMP is then in the high state. When the switch SW1 is open, the capacitor C discharges until reaching the switching threshold of the comparator. The time elapsed between the opening of the switch SW1 and the switching of the comparator CMP is representative of the value of the measured physical parameter.

FIG. 7 is an electrical diagram of another variant embodiment of the measurement circuit MES of FIG. 5. The measurement circuit MES of FIG. 7 differs from that of FIG. 5 in that, in the circuit of FIG. 7, the switch SW2 has been removed, and the resistor R and the capacitor C are connected in parallel between the input of the comparator CMP and the terminal val +. The switch SW1 connects the input of the comparator CMP to the terminal val-.

The operation of the circuit of FIG. 7 is as follows. When the switch SW1 is in the on state, the input voltage Vin of the comparator CMP is canceled. The output voltage Vout of the comparator CMP is then in the low state. When the switch SW1 is open, the input voltage Vin of the comparator CMP progressively rises to the switching threshold of the comparator CMP, at a speed which depends on the value of the measured physical parameter.

It will be noted that in the examples of FIGS. 5, 6 and 7, the switches SW1 and, if appropriate, SW2, are controlled by the signal applied to the input terminal Din of the measurement unit, which corresponds to the signal supplied. at the output terminal Dout of the previous rank measurement unit in the unit of measurement chain. In practice, so that the changes of state of the output Dout of the previous rank measurement unit make it possible to control the switches SW1 and, if appropriate, SW2, connection capacities can be provided between the terminal Din and the or the control terminals of the switch or switches.

FIG. 8 is an electrical diagram illustrating an alternative embodiment of the measurement circuit MES of FIG. 7, including such a connection capacitance.

The measuring circuit MES of FIG. 8 comprises the same elements as the measuring circuit MES of FIG. 7, arranged in substantially the same manner. In this example, the comparator CMP is formed by an inverting gate whose low and high supply terminals are respectively connected to the terminal val- and terminal val +. The comparison threshold is substantially equal to half the supply voltage of the measurement unit. In addition, in this example, the switch SW1 is an N-channel MOS transistor whose drain (d) is connected to the input of the comparator CMP, and whose source (s) is connected to the terminal val-. The measurement circuit MES of FIG. 8 furthermore comprises a connection capacitor C1 whose first electrode is connected to the control gate (g) of the switch SW1 and whose second electrode is connected to the terminal Din. The measurement circuit MES of FIG. 8 further comprises a bias resistor Rp whose first end is connected to the control gate of the switch SW1 and whose second end is connected to the terminal val +.

By default, the bias resistor Rp keeps the transistor SW1 in the closed state. The default potential of the Din terminal is the high potential of the output terminal Dout of the previous rank measurement unit, substantially equal to the potential of the low supply terminal of the measurement unit under consideration (at note that in the example of Figure 8, the inverting gate complements the result of the comparison, that is to say that the output voltage Vout is low when the input voltage Vin is greater than the comparison threshold, and in the high state when the input voltage Vout is below the comparison threshold). The connection capacitance C1 is then by default charged to the power supply voltage of the measurement unit, via the bias resistor Rp. When the output Dout of the measurement unit of the previous rank goes to the low state ( at the end of the delay generated by the previous rank measurement unit in the chain), the source gate voltage of the transistor SW1 is canceled, causing the switch SW1 to open, and therefore the delay generated by the measuring circuit MES. Alternatively, rather than using a connection capacity between the Din terminal and the control terminal (s) of the or switches, it can be provided to use a comparator type CMP collector or open drain.

FIG. 9 is an electrical diagram illustrating an alternative embodiment of the measurement circuit MES of FIG. 7, in which the comparator CMP is an open collector or drain type comparator.

The measurement circuit MES of FIG. 9 comprises the same elements as the measurement circuit MES of FIG. 7, arranged in substantially the same manner. In this example, the comparator CMP is of open drain or open collector type. The switch SW1 is an N-channel MOS transistor whose drain (d) is connected to the input of the comparator CMP, and whose source (s) is connected to the terminal val-. The measurement circuit MES of FIG. 9 further comprises a bias resistor Rp whose first end is connected to the control gate of the switch SW1 and whose second end is connected to the terminal val +. The use of a comparator with drain or open collector makes it possible to freely choose the level of potential taken by the output terminal Dout of the comparator when the output of the comparator is in the high state. In the example of FIG. 9, this potential is reduced substantially to the potential of the high-voltage supply terminal + of the higher-order measuring unit in the measurement unit chain, by the polarization resistor Rp of the unit of higher rank. This leads to keeping the transistor SW1 of the higher-order unit of measurement closed. When the output Dout of the comparator CMP goes low, the potential of the terminal Dout becomes substantially equal to the potential of the low supply terminal of the current measurement unit, which leads to opening the transistor SW1 of the higher-ranking unit of measure.

FIG. 10 is a circuit diagram of an exemplary embodiment of the propagation circuit PROP of the measurement unit MUi of FIG. 2.

In this example, the PROP propagation circuit is adapted to implement an EXCLUSIVE OR type function.

Prop propagation circuit comprises an EXCLUSIVE OR gate with two inputs el and e2 and an output si, designated by the reference XOR in the figure. The circuit PROP further comprises a P-channel MOS transistor 121 in the example shown, the source (s) of which is connected to the high voltage supply terminal + of the measurement unit, and whose drain (d) is connected to the low voltage supply terminal of the measurement unit via a bias resistor 123. The input el of the XOR gate is connected to the drain of the transistor 121, and the input e2 XOR gate is connected firstly to the terminal Sin and secondly to the terminal val + through a bias resistor 125. The circuit PROP further comprises a MOS transistor 127, N channel in the example shown, whose source (s) is connected to the terminal val-, whose drain (d) is connected to the terminal Sout via a bias resistor 129, and whose gate (g) is connected to the output if of the XOR gate.

If the terminal Dout is at a high logic level (potential greater than or equal to that of the high voltage supply terminal + of the measuring unit), the transistor 121 is in the open state, and the input el of the XOR gate is kept low by the resistor 123. If the terminal Dout is at a low logic level, the transistor 121 is in the closed state, and the input el of the XOR gate is in the high state. . If the Sin terminal is at a logic high level (transistor 127 of the previous rank measurement unit open), the input e2 of the XOR gate is pulled high by the resistor 125. If the Sin terminal is at a low logic level (transistor 127 of the previously closed rank unit of measurement), the input e2 of the XOR gate is in the low state. The resistor 129 makes it possible to prevent the input voltage of the logic gate of the higher-order measurement unit from becoming negative.

FIG. 11 is a circuit diagram of another exemplary embodiment of the propagation circuit PROP of the measurement unit MUi of FIG. 2.

In this example, the propagation circuit PROP is adapted to implement a function of the NAND type.

Prop propagation circuit comprises two N-channel MOS 131 and 133 transistors in the example shown. The transistor 131 has its source (s) connected to the low supply terminal val-of the measurement unit, its gate (g) connected to the terminal Dout, and its drain (d) connected to the source (s) of the transistor 133. The transistor 133 has its gate (g) connected to the terminal Sin and its drain (d) connected to the terminal Sout. The circuit PROP further comprises a resistor 135 connecting the terminal Sin to the upper supply terminal val + of the measurement unit.

The output Sout is in the low state only when the transistors 131 and 133 are closed, that is to say when the terminals Dout and Sin are in the high state. The assembly of FIG. 11 thus performs a NAND function. This arrangement is compatible with an operation in which the potential of the terminal Dout exceeds, in the high state, the potential of the high power supply terminal val +. In addition, this arrangement is compatible with an operation in which the potential of the terminal Sin, in the low state, is lower than the potential of the low supply terminal val-.

The operation of the PROP circuit of FIG. 11 is as follows. When the Dout terminal is in the high state (default state in this example), the complemented value of the signal present on the Sin terminal is directly reproduced on the Sout terminal. There is therefore immediate propagation of changes of state occurring in the previous units of measurement. When the delay of the current measurement unit is triggered, that is, when the Din input goes low in this example, the Sin input is set high (the Sout output is then in the low state). In practice, this can be done by applying a rising edge on the input Sin of the first measurement unit of the chain while a falling edge is applied to the input Din of this same first measurement unit. When the time has elapsed, the output Dout goes low, causing transistor 131 to open. The output Sout then goes high. Then, the output Dout being low, the output Sout remains maintained high. Status changes are no longer transmitted by the unit of measurement until the next reset.

FIG. 12 is a circuit diagram of another exemplary embodiment of the propagation circuit PROP of the measurement unit MUi of FIG. 2.

In this example, the propagation circuit PROP is adapted to generate a voltage pulse on the terminal Sout at the end of the delay set by the measurement circuit MES, and to propagate without delay the voltage pulses generated on the terminals Sout of the units previous rank measurement in the unit of measurement chain. In this example, the potential of the terminal Sout is by default in the low state, and is briefly set high during the pulses.

The circuit PROP comprises a diode 141 whose anode is connected to the terminal Dout and whose cathode is connected to the terminal Sout, a connection capacitor 143 whose first electrode is connected to the terminal Sout and whose second electrode is connected. at the terminal Sin, and a resistor 145 whose first end is connected to the terminal Sout and whose second end is connected to the terminal val-.

By default, the terminals Dout and Sout are at substantially the same potential as the low voltage supply terminal. When a rising edge is applied to the terminal Dout, the diode 141 becomes conductive and the rising edge is reproduced on the terminal Sout. This rising edge is further reproduced on the terminal Sin via the connection capacitor 143. In practice, this rising edge is reflected on all the terminals Sin and Sout of the chain of measurement units, via the Link capacitors 143. Thus, when a rising edge is applied to the output terminal Dout of one of the units of measurement, all the units of measurement will see an overvoltage on their terminals Sin and Sout. This overvoltage is temporary, and in each unit of measurement, the potential of the terminal Sout is rapidly reduced to either the potential of the low supply terminal of the unit of measurement via the resistor 145 if the Terminal Dout is in the low state, ie at the potential of the terminal Dout via the diode 141 if the terminal Dout is in the high state.

FIG. 13 is an electrical diagram of an alternative embodiment of the propagation circuit PROP of FIG. 12. In this example, the potential of the terminal Sout is by default in the high state, and is briefly put in the state low during impulses.

The circuit PROP of FIG. 13 comprises the same elements as the circuit PROP of FIG. 12, but, in the example of FIG. 13, the diode 141 has its anode connected to the terminal Sout, and its cathode connected to the terminal Dout, and the resistor 145 connects the Sout terminal to the high voltage supply terminal + of the measurement unit.

Particular embodiments have been described. Various variations and modifications will be apparent to those skilled in the art. In particular, the embodiments described are not limited to the exemplary embodiments of the MES measurement and PROP propagation circuits described in relation with FIGS. 5 to 13.

In addition, the embodiments described are not limited to the particular example shown in FIG. 1, in which the cells under surveillance are connected in series. In practice, the described management device operates regardless of the interconnection diagram of the cells under surveillance.

In addition, the described embodiments can be adapted to other types of assembly than batteries. By way of example, the embodiments described can be implemented in a photovoltaic panel type assembly, the cells under surveillance then being photovoltaic cells connected in series and / or in parallel between voltage supply terminals. Alternatively, as shown schematically in Figure 14, the described embodiments can be implemented in a fuel cell type assembly comprising a stack of elementary cells celll, cell2,. . . connected in series. The cells under surveillance are then the elementary cells of the fuel cell. In this case, the measurement units MU1, MU2, ... MUN of the management device can be realized in the form of printed circuit boards, each printed circuit board corresponding to a measurement unit. Each printed circuit board may be disposed substantially in the same medium plane as the cell with which it is associated, and be mounted integral with the cell with which it is associated. The different printed circuit boards can be stacked substantially in the same order as the cells of the fuel cell. Electrical connection elements, for example spring blades, can be arranged on the lower and upper faces of each measuring unit to form the connection terminals Din, Sin, Dout and Sout, so that the chain link of the units MUi does not require intermediate cables between two successive measuring units. Alternatively, as shown schematically in FIG. 15, to protect the electronic cards against shocks, the latter can be integrated within the fuel cell itself in a cavity 151 passing through all the cells of the battery. fuel and sealed by a peripheral seal 153 disposed at each cell, between the conductive plates forming the current collectors of each of them.

Moreover, the embodiments described can be adapted to a management device measuring several physical parameters per cell. In this case, several measurement units connected in a chain can be associated with each storage cell or electrical energy production, these cells possibly being able to share the same propagation circuit adapted to receive the signals supplied by the output terminals Dout des different units of measurement associated with the cell.

In the embodiments described, the cells monitored by the measurement units may be elementary cells of the assembly, or groups of several elementary cells connected in series and / or in parallel. For example, in the case of a photovoltaic power generation panel, the monitored cells may be groups of several elementary photovoltaic cells, in order to limit the number of measurement units equipping the panel.

Furthermore, it will be noted that in the examples described with reference to FIGS. 5 to 9, the comparator CMP may be a simple transistor whose switching threshold is fixed by the voltage applied to its control terminal in opening and closing (gate or base).

Claims (11)

An assembly (100) comprising: a plurality of cells (C1, C2, C3, C4) for storing and / or producing electrical energy connected in series and / or in parallel between first (V-) and second ( V +) terminals for supplying a voltage; and a management device (101) comprising a plurality of measurement units (MU1, MU2, MU3, MU4) respectively associated with the different cells of the assembly, each measurement unit (MUi) comprising first (Din) and second (Dout) terminals and a measuring circuit (MES) adapted to transmit on the second terminal (Dout) a change of state of a signal applied to the first terminal (Din), with a delay depending on a physical parameter of the cell associated with it, in which the units of measure (MUI, MU2, MU3, MU4) are connected in a chain so that each unit of measurement (MUi), except for the first of the chain, has its first terminal (Din) connected to the second terminal (Dout) of the previous rank measurement unit in the chain. 2. An assembly (100) according to claim 1, wherein each measurement unit (MUi) further comprises third (Sin) and fourth (Sout) terminals and a propagation circuit (PROP) adapted to transmit without delay on the fourth terminal (Sout) a change of state of a signal applied to the third terminal (Sin) or the second terminal (Dout). 3. An assembly (100) according to claim 2, wherein, in each measurement unit (MUi), the propagation circuit (PROP) is adapted to provide on the fourth terminal (Sout) an output signal corresponding to an EXCLUSIVE OR signals applied to the third (Sin) and second (Dout) terminals. 4. An assembly (100) according to claim 2, wherein, in each measurement unit (MUi), the propagation circuit (PROP) is adapted to provide on the fourth terminal (Sout) an output signal corresponding to a NO AND signals applied to the third (Sin) and second (Dout) terminals. 5. The assembly (100) according to claim 2, wherein, in each measurement unit (MUi), the propagation circuit (PROP) is adapted to generate a pulse on the fourth terminal (Sout) during a change of state of the signal applied on the third terminal (Sin) or on the second terminal (Dout). 6. An assembly (100) according to any one of claims 2 to 5, wherein each measurement unit (MUi), with the exception of the first of the chain, has its third terminal (Sin) connected to the fourth terminal (Sout) of the previous rank measurement unit in the chain. The assembly (100) according to claim 6, wherein the management device (101) further comprises a control circuit (103) connected to the first (Din) and third (Sin) terminals of the first measurement unit (MUI ) of the chain, and the fourth terminal (Sout) of the last unit of measurement (MU4) of the chain. 8. The assembly (100) according to any one of claims 1 to 7, wherein, in each measurement unit (MUi), the measuring circuit (MES) comprises a resistor (R) and a capacitor (C) forming a RC circuit, at least one reset switch (SW1, SW2) of the RC circuit whose control gate is connected to the first terminal (Din) of the measurement unit, and a comparator (CMP) whose input is connected to an electrode of the capacitor (C) and whose output is connected to the second terminal (Dout) of the measurement unit. 9. Assembly (100) according to claim 8, comprising at least one bonding capacity (Cl) between the first terminal (Din) of the measurement unit and the control gate of said at least one switch (SW1, SW2). An assembly (100) according to claim 8, wherein, in each measurement unit (MUi), the comparator (CMP) is of open drain or open collector type. 11. An assembly (100) according to any one of claims 2 to 7, wherein: each unit of measurement (MUi) is a printed circuit board, the first (Din) and third (Sin) terminals of the unit of measurement being arranged on a first face of the printed circuit board, and the second (Dout) and fourth (Sout) terminals of the measurement unit being arranged on a second face of the printed circuit board, respectively opposite the first (Din) and third (Sin) terminals; and the units of measurement (MUi) are stacked so that each unit of measurement, except the first one of the stack, has its first (Din) and third (Sin) terminals in contact respectively with the second (Dout). ) and fourth (Sout) terminals of the previous rank measurement unit in the stack.