Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
  • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
  • H02J7/34—Parallel operation in networks using both storage and other dc sources, e.g. providing buffering
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
  • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
  • H02J7/14—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries for charging batteries from dynamo-electric generators driven at varying speed, e.g. on vehicle

Definitions

• the present invention relates to an interface device between two parts of an electrical network.
• the invention finds a particularly advantageous application in the field of power supply of the vehicle network of vehicles, including motor vehicles with a combustion engine equipped with a system for stopping and restarting the engine automatically, such as the system known as "Stop and Start”.
• the DC power supply of electrical equipment connected to the on-board electrical system of a motor vehicle is provided, on the one hand, by an alternator, driven by the heat engine, whose alternating output current is rectified by an AC / DC converter, and on the other hand by a DC battery.
• the alternator is intended, when the engine is in operation, to supply the electrical equipment of the network and charge the battery, while the latter is generally intended to power the equipment when the engine is stopped, for example to allow the starting the engine, the operation of the car radio, lighting, etc.
• the alternator is able to ensure by itself the DC requirements of all the equipment of the on-board electrical network.
• the network power returns to the single battery.
• the vehicle's electrical network can be subject to large current draws, which can cause large voltage drops. This is particularly the case during the automatic restart phases of the "Stop and Start" system, during which the battery must supply the alternator, then operating as an alternator-starter, with the current needed to restart the engine.
• voltage drops in the battery of several volts can be observed, up to 6 V, so that during these transient phases of a duration of the order of a few hundred milliseconds, the voltage supplied by the battery decreases from a nominal value of the order of 12 V to a value of about 6 V or less.
• 2 923 328 proposes a partition of the vehicle electrical network in two parts between which is disposed an interface device, namely, on the one hand , a first part, upstream of the interface device, comprising in particular the alternator, or alternator-starter, and its A / C converter, the battery and the starter, and, secondly, a second part, downstream the interface device, comprising one or more sensitive equipment as defined above.
• an interface device namely, on the one hand , a first part, upstream of the interface device, comprising in particular the alternator, or alternator-starter, and its A / C converter, the battery and the starter, and, secondly, a second part, downstream the interface device, comprising one or more sensitive equipment as defined above.
• the interface device is designed to maintain its output voltage, i.e. the voltage applied to the second network portion, at a constant target value regardless of the input voltage of the device .
• the nominal voltage is usually the nominal voltage of the battery of about 12 V.
• the interface device is controlled by a control module, so that in case of drop of the battery voltage below its nominal value of 1 2 V, due in particular to an automatic restart of the "Stop and Start" system, the device is activated in order to provide an output voltage equal to the set voltage, for example set at 12 V. In the absence voltage drop, the function of the interface device is limited to transmitting directly to the second network part the voltage supplied by the battery.
• an interface device between, on the one hand, a first part of an electrical network, comprising a dc power supply source, suitable applying an input voltage to the interface device, and secondly a second network portion comprising at least one device for supplying direct current from the interface device, said interface device being capable of delivering on the second network part an output voltage equal to a set value when the input voltage falls below a given nominal value, which is remarkable in that the setpoint value is limited to values lower than the nominal value, defined so as to guarantee operational operation of said equipment and to minimize the electrical energy supplied by the interface device.
• the invention takes advantage of the fact that the sensitive equipment of the second network part can remain operational during a transient phase of short duration, a few hundred milliseconds, at a minimum supply voltage, 10 V for example, lower than the rated voltage of the battery. It is therefore possible, during the transient phase, to impose on the interface device a reference voltage equal to the minimum supply voltage, which is lower than the nominal voltage of the battery. It is thus possible to ensure the operational operation of the sensitive equipment, while limiting as much as possible the power developed by the interface device according to the invention, unlike the known device described above.
• the set value of the output voltage to be delivered by the interface device is defined by a pre-established correspondence table between measured values of the input voltage and the setpoint values.
• the set value of the output voltage to be delivered by the interface device is defined by the average of the measured values of the input voltage inside a time window. of given width.
• the invention provides that the set value is at least equal to a given minimum threshold.
• Figure 1 is a diagram of an electrical network equipped with an interface device according to the invention.
• Figure 2 is an embodiment diagram of an interface device according to the invention.
• Figure 3a shows a correspondence table implemented by a first embodiment of an interface device according to the invention.
• FIG. 3b is a diagram of the evolution as a function of time of the input and output voltages of the interface device according to the first embodiment.
• FIG. 4 is a diagram of the evolution as a function of time of the input and output voltages of the interface device according to a second embodiment.
• the first network portion Pi comprises a power source 1 1 capable of delivering a direct current. at a nominal voltage V 0 .
• the power source 1 1 is the vehicle battery, the nominal value V 0 supplied by the battery being generally of the order of 12 V.
• the first Pi network portion also comprises a second source 1 2 DC power supply constituted by the alternator 121 of the vehicle and an AC / DC converter 122.
• the alternator 121 is an alternator-starter, that is to say an electric machine that can operate as a current generator when the heat engine is running, or as a starter during the automatic restart phases, the current required then being provided by the battery 1 1.
• the electrical power to be supplied to the alternator / starter 1 21 is then such that, during the automatic restart of the motor, significant drops in the voltage V- ⁇ at the terminals of the battery can occur, of the order of 6 V , the voltage V- ⁇ rising from 12 V to about 6 V.
• the electrical equipment EQ- ⁇ such as electromagnetic valves or the electric turbocharger, capable of operating at a minimum voltage of about 6 V are grouped in the first part Pi network.
• the second portion P 2 network includes sensitive electrical equipment EQ 2 mentioned above, which require a minimum operating voltage greater than 6 V, 1 0 V for example.
• an interface device 20 is provided between the first P 1 and the P 2 P 2 network part. in order to compensate for the drop of the voltage V- ⁇ of the battery from the nominal value V 0 of 12 V to a voltage Vi of approximately 6 V.
• the interface device 20 delivers at the second portion P 2 of a network voltage V 2 output equal to a con s V set value, which must be at least equal to the minimum operating value of sensitive equipment EQ 2.
• the interface device 20 can be deactivated to transmit directly to the second network part P 2 the DC voltage, then greater than 10 V, supplied by the alternator 1 21 and the A / C converter 122.
• the switching of the interface device 20 between an active state and an inactive state is performed by means of a control module 13 connected to the first network part P 2 so as to be able to monitor the variations of the voltage V -, input and control the interface device 20 accordingly. If the voltage V becomes lower than the rated voltage V-
• FIG. 2 gives the diagram of an exemplary embodiment of the interface device 20.
• This is a circuit known to those skilled in the art under the name of "push-pull".
• the regulation of the output voltage V 2 of the device is carried out by the control module 13 by controlling the opening and closing of the switches 21, 22 according to a duty cycle defined so as to obtain the voltage V CO ns of desired setpoint.
• a "bypass" switch 23 also controlled by the control module 1 3, makes it possible to activate or deactivate the interface device 20 as a function of the values of the input voltage V-1 observed on the first network part Pi by the control module 13.
• the switches 21, 22 and the switch 23 are for example made by MOSFET transistors, as shown in Figure 2.
• the invention proposes to limit the value V cons of set to values allowing the time to guarantee the operational operation of the EQ equipment 2 and to minimize the electrical energy supplied by the interface device 20, unlike the interface device, object of the French patent application No. 2 923 328, which is controlled by the control module so as to output uniformly the same output voltage of 12 V, regardless of the value of the input voltage. Having thus reduced the electrical power developed by the interface device 20, it is then possible to envisage using less expensive and less bulky electronic components.
• the setpoint V CO ns values to be applied can be defined by a predefined correspondence table and stored in the control module 13, such as the table shown in FIG. 3a. It can be seen from this table that the setpoint values vary as a function of the values of the input voltage V- ⁇ recorded by the module 13 when this is lower than the nominal value V 0 of 10 V. In the example proposed values, V CO ns setpoint values vary in stages.
• FIG. 3b illustrates the variations of the output voltage V 2 as a function of those of the input voltage Vi.
• FIG. 4 illustrates a second way of defining the setpoint Vcons values to be applied to the output voltage V 2 , which consists of calculating the average of the input voltage V inside a window. temporal F of given width I. As long as the voltage ⁇ remains equal in the window F to the nominal voltage V-io of 12 V, its average is equal to Vi 0 and the device 20 is not activated by the control module 13. As soon as a decrease of the voltage V- ⁇ appears inside the window F, the average of V- in this window becomes lower than the nominal value V 0 . The control module 13 detects this decrease and then takes for con s V set value to impose on the device 20 from the interface Vi calculated in the window F.
• the voltage V CO ns setpoint applied to the interface device 20 always remains lower than the nominal voltage V 0 , which limits the electrical energy provided by the device 20 and allows the use of inexpensive components and bulky.
• the control module 13 compares the average of the voltage V i calculated on the window F at the threshold Vseuii and, in the case of a negative comparison, takes the value of V only for value V with setpoint.
• the width I of the window F is at most equal to the width of the peak p of drop of the voltage V 1. as shown in Figure 4.

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Direct Current Feeding And Distribution (AREA)
• Small-Scale Networks (AREA)
• Secondary Cells (AREA)
• Charge And Discharge Circuits For Batteries Or The Like (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=42937695

Family Applications (1)

Country Status (4)

Families Citing this family (2)

Family Cites Families (5)

• 2010
  • 2010-01-29 FR FR1050616A patent/FR2955985B1/fr not_active Expired - Fee Related
  • 2010-12-15 WO PCT/FR2010/052749 patent/WO2011092384A2/fr active Application Filing
  • 2010-12-15 CN CN201080062536.6A patent/CN102725938B/zh not_active Expired - Fee Related
  • 2010-12-15 EP EP10809027A patent/EP2529466A2/de not_active Withdrawn

Non-Patent Citations (1)

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