JP2020533935A - Voltage converters and related chargers onboard automatic vehicles - Google Patents

Abstract

The present invention relates to a voltage converter (200) mounted on an automatic vehicle for converting a first voltage into a second voltage different from the first voltage, each of which produces a second voltage. A plurality of cells (C) including transistor arms (T3, T4) controlled as choppers, at least one separation transistor (K3-R), and a circuit (210) for controlling the transistor. The control circuit (210) separates one cell from the plurality of cells and uses at least one separation transistor (K5, K6) to supply a third output voltage. K3-R) is configured to be selectively left open.

Description

The present invention relates to charging the battery of a device or device that uses an electric vehicle or a hybrid vehicle.

The present invention particularly relates to voltage converters mounted on electric or hybrid vehicles configured to perform additional functions of electric chargers.

In a known method, the motor vehicle comprises a DC / DC voltage converter configured to convert, for example, a first input voltage of 48V to a second output voltage of, for example, 12V.

Further, the automatic vehicle may be provided with a battery charger capable of charging the battery of the device or equipment with a third output voltage different from the second voltage by a known method, wherein the third voltage is For example, it may be 48V, 24V or 12V.

In known automated vehicles, the functions of the DC / DC voltage converter and battery charger are performed by two separate electronic modules.

Hybrid or electric vehicles need to be further improved to minimize the cost and size of in-vehicle electronic systems. An object of the present invention is to satisfy this need, and according to one of the embodiments, for mounting on an automatic vehicle and converting a first voltage into a second voltage different from the first voltage. It is a voltage converter, and the voltage converter is
Multiple cells, each containing a transistor arm controlled as a chopper to generate a second voltage,
With at least one separating transistor,
Equipped with a circuit for controlling transistors,
The control circuit selectively opened the at least one separation transistor K3-R in order to separate one cell from the plurality of cells and use the arm of the cell to supply a third output voltage. Configured to be left alone.

The separation transistor allows protection in the event that the polarity of the second voltage is reversed.

In other words, the isolation transistor K3-R is used as an electronic switch that opens (turns off the switch) or closes (turns on the switch).

The first voltage is supplied by an electrical supply system, which may be, for example, a battery.

By opening the separation transistor K3-R, the arm of the cell can be separated from another cell, which makes it possible to supply a second voltage.

In one particular embodiment of the invention, the at least one separating transistor belongs to one of the plurality of cells.

In one particular embodiment of the invention, the at least one isolation transistor is connected via an inductor to the midpoint of the transistor arm of the cell comprising the at least one isolation transistor. Therefore, the cell including the at least one separation transistor also includes an inductor.

In one particular embodiment of the invention, the converter cells are arranged in parallel. In other words, the converter cells are electrically connected in parallel.

The present invention combines electronic functions performed by separate components in a known manner, which makes it possible to reduce overall size as well as manufacturing costs.

In addition, the cooling and control circuits may be the same, which further contributes to size reduction as well as manufacturing costs.

The third output voltage may or may not be equal to the first voltage.

The third voltage may be used to charge a battery, eg, a battery of an external device or device of an automatic vehicle, such as a battery of an electric bicycle.

In one embodiment, the third voltage is equal to the first voltage, both being, for example, 48V. The converter is then used as a charger.

In one modified embodiment, the third voltage is different from the first voltage. In this case, the converter is a dual output converter, the second output of which is used as a charger. The first voltage may be 48V. The third voltage may be 12V or 24V.

In one embodiment, the converter according to the invention is used to supply a second voltage and / or a third voltage starting from the voltage supplied by the vehicle battery.

The second voltage can allow the vehicle-mounted electrical system of the automatic vehicle to be powered, for example to enable the use of an autoradio or other device mounted on the vehicle.

A third voltage can allow the battery, eg, the battery of an electric bicycle, which is desired to be charged in the vehicle, to be powered while the vehicle is driven or stationary.

The third output voltage may be less than 60V, or better, 48V or less. In one embodiment, the third output voltage is 48V or 24V or 12V.

In one particular embodiment, the third output voltage is preferably a DC voltage of less than 60V or less than 48V. In one particular embodiment, the third output DC voltage is 48V. In one particular embodiment, the third output DC voltage is 24V. In one particular embodiment, the third output DC voltage is 12V.

The second output voltage may be less than 60V, or better, 48V or less. In one embodiment, the second output voltage is 12V or 24V.

In one particular embodiment, the second output voltage is preferably a DC voltage of less than 60V or less than 48V. In one embodiment, the second output DC voltage is 12V or 24V.

According to the present invention, the separation transistor is opened to separate the cell and use the arm of the cell controlled as a chopper to supply a third output voltage. In this case, the converter is configured to supply the second and third output voltages simultaneously or otherwise. It is also open in the event of a failure and acts as an isolator. When it is closed, the corresponding cell is used as a cell in a conventional DC / DC voltage converter, allowing all cells in the converter to be supplied with only a second voltage.

The converter cells are arranged in parallel. The converter may include several cells, such as 2, 3, 4, 5, or 6 cells.

Depending on the application, the converter requires only one or more cells of the plurality of cells to supply the second voltage, and the other cells of the plurality of cells are unused. In that case, it is advantageous to use the arm of the unused cell to supply the third voltage both when the vehicle is driving and when it is stationary.

In one exemplary embodiment, there are four cells arranged in parallel. The separation transistor of each cell may be connected to the midpoint of the transistor arm of each cell via an inductor.

The cells of the cell are controlled in the same way and in the same operating cycle as a conventional DC / DC voltage converter. One of the transistors in the cell arm opens, the other conducts, and vice versa. There is a T / x phase shift between the transistor open / close commands of the various cells, where x is the number of active cells supplying the second voltage and T is the duration of the operating cycle. In other words, the duty cycle within each cell is the same, but the transistor commands are phase-shifted from one cell to another by T / x. The phase shift may be T / 4 or T / 3, depending on, for example, the open state or the closed state of the separation transistor K3-R.

In the present invention, the arm of a cell controlled as a chopper is used to perform other cells of a plurality of cells performing charger functions, particularly 48V, 24V or 12V, and DC / DC voltage converter functions. Will be understood.

In one particular embodiment of the invention, the converter may include capacitance C1 connected to the output of the converter cell. In the case of a cell separation transistor whose arm is controlled as a chopper, the capacitance C1 is connected to the output of the cell of the converter excluding the cell whose arm is controlled as a chopper. When this separation transistor is closed, the cell is used in the converter to supply a second voltage and the capacitance C1 is connected to the outputs of all cells in the converter.

The capacitance C1 connected to the output of the cell of the converter may be electroless. In particular, it may be a ceramic capacitor.

Further, when the number of cells of the converter is small, it is necessary to increase the capacitance value. For example, in the case of a converter with two cells, the capacitance should be twice the capacitance required for a converter with four cells.

In one particular embodiment of the invention, at least one isolation transistor TR is associated with one or more of the cells. These transistors provide protection against inversion of the polarity of the second voltage.

In one particular embodiment of the invention, the converter may further include a safety transistor TS between the at least one separation transistor TR and the output of the second voltage. These safety transistors provide protection against voltage fluctuations in the electrical system that supplies the first voltage. The converter may include one safety transistor TS for each cell of the converter. The converter may include one or more separation transistors, eg, 1, 2, 3, 4, 5 or 6 separation transistors. The large number of isolation transistors can improve the power of the entire assembly. In one exemplary embodiment, there are four separate transistors arranged in parallel, each connected to the output of the cell.

In one particular embodiment of the invention, the converter may further include an additional isolation transistor K4-R located just upstream of the output of the third voltage.

In one particular embodiment of the invention, the converter may further include a capacitance C3 connected to an additional isolation transistor K4-R via one of its terminals. The capacitance C3 may be connected between the safety transistor TS described above and the additional separation transistor K4-R.

In one particular embodiment of the invention, the converter may further include an additional safety transistor K1-S upstream of the additional isolation transistor K4-R.

In one particular embodiment of the invention, the separable arms K5, K6 of the cell are controlled as step-down choppers for supplying a third output voltage.

In a particular embodiment of the invention, the converter may further include, along with an additional safety transistor K1-S, transistors K1-S, transistors K2 forming K2, which are controlled as boost choppers. K1-S and K2 form a back boost circuit together with the arms K5 and K6 of the cell that can be separated.

In one particular embodiment, the additional safety transistor K1-S is placed directly at the output of the cell whose arm is controlled as a chopper. In this case, the third voltage may be 12V or 24V. The load may be cut off if the electronic components of the converter fail.

In one particular embodiment, the converter may further include a precharge transistor K7, and the control circuit is supplied with a second voltage and / or a third voltage when the precharge transistor K7 is open. When the precharge transistor K7 is closed, the arm of the cell, which is controlled as a chopper, becomes the capacitance of the electrical system that supplies the first voltage, or the capacitance of one or more of the converters. It is configured to allow it to be used as a simple current transistor to supply a precharge current.

In the case of this precharge, the separation transistor K3-R and the additional separation transistor K4-R remain open, while the precharge transistor K7 remains closed.

If there is no precharge, the precharge transistor K7 remains open.

Another subject of the present invention is an automatic vehicle with a converter as described above, independent of or in combination with the aforementioned subject matter. The automatic vehicle may be either an electric automatic vehicle or a hybrid automatic vehicle.

Yet another subject of the present invention is a method for supplying power to a battery by a converter according to the present invention, in which the first voltage is first by controlling a plurality of cells C as choppers. Each of the cells C is provided with transistor arms T3, T4 for generating a second voltage, allowing conversion to a second voltage different from the voltage. According to such a method, at least one is used to separate the cells and use the arms K5, K6 of the cell, which are controlled as choppers for supplying the third output voltage supplied to the battery. The two separation transistors K3-R are selectively left open.

To this end, the converter comprises a circuit (210) for controlling the transistors, as described above.

The method can include all or part of the above features of the invention.

The present invention will be better understood by reading the following detailed description of the latter non-limiting exemplary embodiment and reviewing the accompanying drawings.

It is a figure which shows the electric circuit of a DC / DC converter. It is a figure which shows the modification embodiment of the converter electric circuit by this invention. It is a figure which shows the modification embodiment of the converter electric circuit by this invention. It is a figure which shows the modification embodiment of the converter electric circuit by this invention.

DC / DC Main Voltage Converter FIG. 1 shows a main DC / DC voltage converter 100 configured to convert a first input voltage, such as 48V, to a second output voltage, such as 12V.

The mains voltage converter 100 includes a bridge that acts as a chopper in a manner known per se. Such a converter is called a buck converter and converts a DC voltage into another DC voltage with a lower value. In an exemplary embodiment, this could be, for example, the case of converting a voltage of 48V to a voltage of 12V.

In the exemplary embodiment of FIG. 1, the DC / DC converter 100 includes four cells C arranged in parallel. Of course, the number of cells C may be different without departing from the scope of the present invention. For example, there may be 2 to 12 cells, such as 2, 3, 4, 5, or 6 cells.

By using a plurality of cells, stress on the semiconductor can be reduced. Therefore, since all the cells of the converter are connected to the same output capacitor C2 having a T / 4 phase difference between the control of the transistors of each contiguous cell, an interleaved converter is referred to, where T is the operation cycle of the converter. It is a cycle. In other words, the duty cycle within each cell is the same, but the transistor control is phase-shifted from one cell to another by T / 4.

The output capacitor C2 is electroless.

Each cell C includes a first transistor T1, a second transistor T2, and an inductor L1.

In the example described here, the transistors T1 and T2 are MOSFETs.

The operation of such a converter 100 can be divided into two configurations according to the state of the transistor T1.

In the conducting state, the transistor T1 is closed and the current flowing through the inductor L1 increases. Since the voltage between the terminals of the second transistor T2 is negative, no current flows.

In the non-conducting state, the transistor T1 is open. The second transistor T2 is brought into a conductive state in order to ensure the continuity of the current in the inductor L1. The current flowing through the inductor L1 is reduced.

Further, the converter 100 is directly connected to the output of one or more cells C and provides a separation switch TR that supplies an output voltage when closed and protects one or more cells C when open. Including.

The converter 100 also includes a safety switch TS, each of which is mounted in series with a corresponding isolation switch TR. These safety switches TS provide output voltage when closed and protect one or more cells C when open.

Such a configuration prevents the flow of current in both directions. As in the case of a DC / DC converter hardware failure, such as a transistor failure, the isolation and safety switches operate (as open switches) when an undervoltage or overvoltage appears on one of the networks at the input or output. ..

Each pair of isolation and safety switches is mounted in parallel with the other pairs.

In the examples described, the converter includes four pairs of isolation and safety switches, thereby improving the power of the assembly, but if the numbers are different, eg, 1, 2, 3, 5 or 6. However, it does not deviate from the scope of the present invention. As a rule, the number of isolation and safety switches is equal to the number of cells in the converter.

In the examples described, the isolation switch and safety switch are, for example, MOSFET type transistors.

All transistors and switches of converter 100 are controlled by controller 110 of converter 100.

Dual Output Converter Next, a voltage converter mounted on a vehicle according to the present invention for converting a first voltage into a second voltage different from the first voltage will be described.

FIG. 2 is a vehicle-mounted voltage comprising a plurality of cells C each comprising transistor arms T3, T4 controlled as choppers for generating a second voltage, and circuits 210 controlling the transistors. The converter 200 is shown.

In the example described, the converter comprises four cells C arranged in parallel, each of which also comprises at least one isolation transistor TR.

As a modification, only one or more of cells C also includes at least one separation transistor TR.

The separation transistor TR of each cell may be connected to the intermediate point of the transistor arms T3 and T4 of each cell via the inductor L2.

The cell transistors T3, T4 are controlled by the control circuit 210 in the same way as a simple converter, phase-shifted, and controlled in the same operating cycle (ie, the duty cycle is the same). One of the transistors in the cell arm opens, the other conducts, and vice versa.

Further, the control circuit 210 is configured to hold the separation transistor K3-R of one of the plurality of cells in an open state or a closed state.

When the separation transistor K3-R is closed, all cells of the converter controlled by the control circuit 210 allow the supply of a second voltage. After that, there is a T / 4 phase shift between the commands of the various cells.

When the separation transistor K3-R is open, the cell is separated and the arm of the cell controlled as a chopper supplies a third output voltage, which is 12V in the example described in FIG. Used for. In other words, the arm of the disconnected cell can form a step-down circuit. In particular, when the intermediate points of the transistor arms T3 and T4 of this cell are connected to the inductor L2, the step-down circuit is of a type called "back".

The control circuit 210 can disable the transistors T3 and T4 of the other cells of the plurality of cells (eg, by opening them) and the second voltage is no longer available.

As a modification, the control circuit 210 controls the other cells C of the plurality of cells so as to supply a second voltage which is 12V in the described example. In this example, there is a T / 3 phase shift between three different cells that supply the second voltage.

In the examples described, there is a T / x phase shift between the commands of the various cells accordingly, where x is the number of active cells supplying the second voltage. The phase shift may be T / 4 or T / 3, depending on, for example, the open state or the closed state of the separation transistor K3-R. T corresponds to the duration of the control cycle.

The converter 200 includes a capacitance C1 connected to the output of cell C of the converter. When the cell separation transistor K3-R, which can control the arm as a chopper, is open, the capacitance C1 is connected to the output of the other cell of the converter. When the separation transistor K3-R is closed, the cell is used in the converter to supply a second voltage and the capacitance C1 is connected to the outputs of all cells in the converter.

The converter further includes a safety transistor TS between the separation transistor TR and the output of the second voltage. The converter includes one safety transistor TS for each cell of the converter. There are four safety transistors TS arranged in parallel, each connected to the output of cell C.

The converter further comprises an additional isolation transistor K4-R located just upstream of the output of the third voltage.

Finally, the converter comprises an additional safety transistor K1-S just upstream of the additional isolation transistor K4-R and directly at the output of the isolated cell.

The separation transistor TR, safety transistor TS, additional separation transistor K4-R and additional safety transistor K1-S are used as electronic switches that can be opened (switched off) or closed (switched on).

Transistors K1-S and K4-R are connected in series. These safety transistors K1-S and K4-R can provide a third output voltage when closed and protect the separated cells when opened.

Therefore, the load can be separated when the electronic component of the converter fails.

The converter also includes a capacitance C3 connected to the input of an additional isolation transistor K4-R. The capacitance C3 is connected between the additional safety transistor K1-S described above and the additional separation transistor K4-R.

In one variant shown in FIG. 3, the converter also includes an additional transistor arm, which is formed by an additional safety transistor K1-S and an additional transistor K2 located upstream of the additional isolation transistors K4-R. Will be done. The midpoint of this additional transistor arm is further connected to the output of the cell which can be separated by the transistor K3-R.

In other words, the inductor L2 of the separated cell and the additional transistor arm can form a booster circuit called a "boost" type.

Therefore, when the third voltage is at a lower level than the first voltage (eg, 12V or 24V), the control circuit 210 sets the transistors K3 and K5 so that the separated cells perform the buck circuit function. Control. At the same time, the control circuit 210 opens the additional transistor K2 and closes the additional safety transistor K1-S.

If the third voltage is at the same level as the first voltage, the control circuit 210 switches K3, K5, to form a "backboost" circuit that supplies a third voltage from the first voltage. Controls K2 and K1-S.

In one embodiment, an additional isolation transistor K4-R is arranged between the output of the booster circuit and the output of a third voltage. The load can be separated in the event of a failure in the electronic components of the converter.

In one variant shown in FIG. 4, the converter further provides a precharge function. The latter is realized by an additional precharge transistor K7 that can integrate both precharge and charger functions in the same DC / DC converter.

The control circuit 210 has one or more capacitances of the electrical system that supplies the first voltage when the separation transistor K3-R and the additional separation transistor K4-R are opened simultaneously while the precharge transistor K7 is closed. , Or the arm of the separated cell can be used as a simple current conductor (ie, transistor K5 closes, transistor K6 opens) to supply precharge current to the capacitance of the converter, especially capacitance C2. Is configured to.

Similarly, in the control circuit 210, when the separation transistor K3-R and the precharge transistor K7 are opened at the same time while the additional separation transistor K4-R is closed, the arm of the separated cell applies a third voltage. It is configured to allow it to be used as a voltage converter circuit to form a feeding circuit.
Needless to say, the present invention is not limited to the examples described. In particular, the number of cells may vary.

Claims (14)

A voltage converter (200) mounted on an automatic vehicle for converting a first voltage into a second voltage different from the first voltage. The voltage converter is a voltage converter.
A plurality of cells (C), each containing transistor arms (T3, T4) controlled as choppers for generating the second voltage, and
With at least one separation transistor (K3-R),
A circuit (210) for controlling the transistor is provided.
The control circuit (210) separates one cell from the plurality of cells and uses the arms (K5, K6) of the cell to supply a third output voltage. A voltage converter configured to selectively leave the isolation transistor (K3-R) open. The converter according to claim 1, wherein the at least one separation transistor belongs to one of the cells of the plurality of cells. The converter according to claim 1 or 2, comprising a capacitance (C1) connected to the output of the cell of the converter. The converter according to claim 3, wherein the capacitance (C1) connected to the output of the cell of the converter is electroless. The converter according to any one of claims 1 to 4, further comprising at least one separating transistor (TR) associated with one or more of the plurality of cells. The converter according to claim 5, further comprising a safety transistor (TS) between the at least one separation transistor (TR) and the output of the second voltage. The converter according to any one of claims 1 to 6, further comprising an additional separation transistor (K4-R) arranged immediately upstream of the output of the third voltage. The converter according to claim 7, further comprising a capacitance (C3) connected to the additional separation transistor (K4-R) via one of the terminals. The converter according to claim 7 or 8, further comprising an additional safety transistor (K1-S) upstream of the additional separation transistor (K4-R). The converter according to any one of claims 1 to 9, wherein the arms (K5, K6) of the cell that can be separated are controlled as step-down choppers for supplying the third output voltage. Along with the additional safety transistor (K1-S), a transistor (K2) forming a transistor arm (K1-S, K2) controlled as a boost chopper is provided, and the transistor arm (K1-S, K2) is separated. The converter of claim 9 or 10, wherein together with said arms (K5, K6) of said cell which can be made, form a "backboost" circuit. The control circuit (210) includes the precharge transistor (K7) so that the second voltage and / or the third voltage is supplied when the precharge transistor (K7) is open. When the precharge transistor (K7) is closed, the arm of the cell controlled as a chopper is the capacitance of the electrical system that supplies the first voltage, or one of the converters or The converter according to any one of claims 1 to 11, configured to allow it to be used as a simple current transistor for supplying a precharge current to a plurality of capacitances. A method for supplying electric power to a battery using the converter according to any one of claims 1 to 12, wherein the converter controls a plurality of cells C as choppers to control a first voltage. Each of the cells C includes transistor arms T3 and T4 for generating the second voltage, wherein the supply method is such that the first voltage is converted into a second voltage different from the first voltage. , At least one separating transistor to separate the cell and use the arm (K5, K6) of the cell controlled as a chopper to supply a third output voltage supplied to the battery. A method comprising a step in which (K3-R) is selectively left open. An automatic vehicle comprising the converter (200) according to any one of claims 1 to 12.

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