EP4022736A1

EP4022736A1 - Quick-charging unit

Info

Publication number: EP4022736A1
Application number: EP20761177.3A
Authority: EP
Inventors: Charles RIPPERT
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-08-26
Filing date: 2020-08-20
Publication date: 2022-07-06
Also published as: AU2020335147A1; CA3149736A1; CN114930667A; WO2021037649A1; US20220302743A1; CH716530A2

Abstract

A charging unit comprises a number of stationary capacitors for charging mobile capacitors which can be connected via a connection socket. The charging unit comprises switching mechanisms for connecting a first capacitor to the mobile capacitors and for connecting each additional capacitor step by step. The number and respective capacitances of the stationary capacitors are greater in comparison to the mobile capacitors. Between the individual steps, the stationary capacitors are separated from the mobile capacitors and the capacitors are connected in parallel such that the voltage states thereof can equalize.

Description

Fast charging unit

The invention relates to a quick charging unit for charging mobile capacitors according to the preamble of the claim

1 .

In the as yet unpublished Swiss patent applications 702/18 and 1142/18, methods and devices for charging mobile capacitors at a charging station are described in which the mobile capacitors at a charging station are connected several times in succession to stationary charged capacitors, each of which has a higher charge than that of the mobile capacitors. In the present application, reference is expressly made to these two applications in order not to repeat facts which are described there in detail and which are not directly related to the present invention.

The following terms are used in the present description:

"Mobile capacitors" are those that are not permanently connected to a power grid or the like and therefore have to be charged regularly at charging stations. Typically, these are capacitors that are used in electrically operated vehicles, tools or other applications Capacitors are also referred to as "capacitors to be charged".

“Stationary or charging capacitors” refer to charged capacitors made available in a charging station, to which the mobile capacitors are temporarily connected for charging. The term “relay” also includes improper relays, such as semiconductor relays or other current- or voltage-controlled switches, such as solenoids or IGBTs.

The term "capacitors" also includes all energy stores in which electrical energy is stored physically rather than chemically, that is to say, to put it simply, in an electrostatic field between two plates. The capacitors therefore also include so-called supercapacitors, ultracapacitors, lithium-ion Supercapacitors, hybrid capacitors and the like, as well as possibly future energy-storing components based on the principle of a capacitor.

It is known that when connecting an empty capacitor A with an identical, fully charged capacitor B, the charges are equalized within seconds and two half-fully charged capacitors result. If an empty capacitor A is connected to two fully charged capacitors Bl and B2 connected in series, a fully charged capacitor A and two half-fully charged capacitors B1 and B2 are obtained within seconds.

The sum of all internal resistances of all components, as well as the dimensioning and different charge states of the capacitors involved determine the maximum possible current to be expected, if capacitors B charged more than A charge the former.

Resistors or inductors are currently used to limit the current in the above configuration, which is known to lead to losses. This is a disadvantage of the known methods of charging capacitors. Compared to capacitors connected in parallel, capacitors connected in series enable higher voltages and thus larger amounts of electrical energy to be transmitted. Capacitors to be charged should therefore be charged in series.

According to the state of the art, assemblies of capacitors must have so-called active or passive "balancing", which is necessary so that all cells or capacitors of a compound firstly have the same voltage and secondly no cells above their maximum permissible, specified nominal voltage Balancing is necessary because typically individual, series-connected capacitors (can) have different internal resistances and thus different voltages during a loading process, which could individually lead to damage if the specified maximum voltage is exceeded. This is a further disadvantage of the known methods for charging capacitors, which is why the capacitors to be charged should also be connected in parallel between the energy transfer phases, so that they have the same voltages.

In the case of energy transfer, the physical properties of the respective affected components limit the speed or the amount of energy per time that can be transferred.

If it is not possible to reduce the speed with losses, energy must be transmitted in smaller units. If capacitors load other capacitors, throttling has so far been associated with losses. If capacitors load other capacitors directly, the transfer rate is limited by the greater internal resistance of the capacitors involved.

With ültracapacitors, a considerable amount of electricity is transferred within a very short time. If electronic components such as cables and switching elements are connected in between to control the energy transfer, they increase the total resistance of the circuit, made up of the internal resistance of the capacitors plus that of the switching elements, on the one hand, and on the other hand, most electronic components are not designed for the high currents that occur, which is why they can be damaged and quickly fail over time. This is another disadvantage of the known methods of charging capacitors.

Known ultracapacitors typically have a maximum voltage of 2.7 volts. It is to be expected that future developments will enable higher values. For most applications, however, higher voltages are usually necessary, which is why several or many ultracapacitors connected in series are used.

If you want such a compound with capacitors the same

To fully charge the capacitance, as already mentioned at the beginning, you need twice as many capacitors as are to be charged on the current-supplying side. It is not only possible as an alternative, but is recommended within the meaning of the invention to equip a charging capacitor network with a significantly higher total capacitance, because a fully charged capacitor with a significantly larger capacitance can almost fully fill an empty capacitor with the same maximum voltage loaded, minus the amount of energy given to it, which is expressed in a reduced voltage of the larger capacitor. If you want to charge promptly, a combination of these two variants is also possible.

The invention is based on the object of eliminating the disadvantages mentioned.

According to the invention, this is achieved by the characterizing features of claim 1. In the following, preferred exemplary embodiments of the invention are described with reference to the accompanying drawings. Show it:

1 shows a circuit diagram of a charging unit; FIG. 2 shows diagrams of the charging current

The approach is based on

- that the components used have maximum load capacities, which must be adhered to in a targeted manner,

- That the capacitors to be charged are connected in series, which enables higher voltages at which, with the same currents in the same time units, significantly more energy can be transferred and one

Speed optimization on the part of the capacitors to be loaded corresponds,

- that the charging capacitors are gradually and with increasing number serially combined into a network, what a

Speed optimization on the part of the charging capacitors,

- that a further charging capacitor is added to the network as soon as the resulting network adheres to the maximum load capacity of the components, - That in comparison to the capacitor network to be charged, the charging capacitor network has a significantly larger total capacitance, a higher maximum voltage, and thus a certain oversizing

- and that the energy-supplying capacitors between the portioned, energy-releasing partial phases are connected to one another in parallel, which ideally should also be done with the capacitors to be charged.

The network of stationary capacitors has a significantly larger total capacity than the network of mobile capacitors. The network of stationary capacitors can be operated with a smaller, equal or greater number of capacitors compared to the number of capacitors in the mobile network. Ideally, however, it has a larger number, namely 50% to 100% more than the network of mobile capacitors. If this is not the case, it makes sense to switch the mobile capacitors all the more to parallel for charging.

The following must be taken into account when dimensioning the stationary capacitors:

The more capacitance they have compared to the mobile capacitors to be charged, the more successive charges of mobile capacitor assemblies are possible without intermediate recharging of the stationary capacitor assembly. With sufficient dimensions, (1) cheaper night-time electricity can be "bunkered", (2) peak demand times (rush hour traffic) can be served better or at all, and (3) the electricity grids, which are currently running at 90% of their load capacity, by adjusting the times Loading the stationary capacitors are less stressed. If the stationary capacitors in the present device do not have significantly more capacitance than the mobile capacitors, it can arise, especially if the equalization of the voltages of the stationary capacitors by omitting an intermediate step of parallel switching to equalize that certain stationary capacitors, those which are taken first for the energy transfer, are discharged so much and in further steps first completely discharged and then change the polarity, i.e. are negatively charged, which has three effects: The latter no longer contribute to the charging process because they can no longer give off any energy, they are negatively charged, so they belong to the capacitors to be charged, which makes the charging process more inefficient, and they can be damaged by the polarity change.

This is one reason why the capacity of the stationary capacitors should be much larger than that of the mobile capacitors. If it is not possible to use capacitively larger capacitors in the stationary capacitor network, for example because the largest capacitors currently available on the market are used as mobile capacitors, a stationary capacitor itself can consist of several capacitors connected in parallel. Between individual charging phases or charging pulses during the process of charging mobile capacitors with stationary capacitors, both should be switched in parallel for a moment so that they can "network internally" equalize. If this does not happen on the side of the stationary capacitors, are the equalizing currents after the charging process possibly like this big that they exceed the specifications.

If this is not done on the side of the mobile capacitors, the latter can be damaged by exceeding the specified individual maximum nominal voltage.

The circuit diagram shown in the figure shows a charging unit in the state in which mobile capacitors are not being charged. The charging unit comprises seven capacitors CI to C7 and relays RI to R7 assigned to them.

The relays are of the type Double Pole Double Throw "DPDT" ¹ ("two contacts, two states"), for example OMRON G5V-2 or Finders 40.52.

All relays R1-R7 are in the switching position in which the positive poles of the capacitors are connected to one another via a line LI and their negative poles are connected to one another via a line L2. The capacitors are connected in parallel via the lines LI and L2, as well as via the relays R1-R7.

The control connections of the relays are each connected to a power supply B via switches S1 to S7 and a line L3. The control connections of the relays are also connected to one another via diodes D1 to D6.

The capacitors to be charged are not shown in the figure. They are connected to the connection socket Jl. The connection socket Jl is also used to connect the charging unit to a power source for charging the capacitors C1-C7. The capacitors C1-C7 are interconnected in such a way that they can be arranged in the manner of a stack by actuating the switches S1 to S7, Cl being the lowest capacitor of the stack and being connected first to the connection socket J1 for charging mobile capacitors .

A further relay R8 is arranged between the relay RI and the connecting socket Jl, which is used to connect the charging unit to the connecting socket Jl or to disconnect between them.

The diodes D1 to D6 have the following function: If one of the switches S1 to S7 is actuated, it must be ensured that, together with the corresponding relay, all the "underlying" relays are actuated simultaneously. If, for example, S3 is actuated, the diodes D2 and Dl ensure that not only relay R3 but also relays R2 and Rl are activated. This is essential, as otherwise the various capacitors would be guaranteed to be damaged. In this illustrative example, if only R3 were activated, the situation would be:

-the negative poles of the capacitors Cl, C2, C4 to C7 would be connected to each other,

-the positive poles of the capacitors Cl, C3, C4 to C7 would be connected,

- the negative pole of capacitor C3 would be connected to the positive pole of capacitor C2, which means

-the voltage of C2 plus C3 would be applied to the capacitors Cl,

C4 to C7 are present and thus destroy the latter if one assumes that the stationary capacitors should be charged to significantly more than 50% in order to be able to (meaningfully) perform their function. In other words, the diodes D1 to D6 catch this problem. It should also be taken into account that this problem is independent of the state of R8, but if partially charged mobile capacitors are also connected via an activated relay R8 at the same time, capacitors C2 and C3 may also be damaged.

In order to ensure the safe behavior of the system, the principle must be taken into account that first (and depending on the state of charge of the mobile capacitors) switches S1 to S7 should be activated, and only then switch S8, which enables more cost-effective relays for To use RI to R7, assuming that the relay R8 is correctly dimensioned, ie much more stable than the former 7. With more stable dimensioning it is meant that RI to R7 must be able to conduct the same currents that R8 must be able to switch makes a significant difference.

The following is not listed in this circuit diagram;

Voltage sensor, which is connected to the mobile

Capacitors measures the voltage and forwards this to the control electronics, which interrupts the charging process, i.e. ends as soon as the maximum permissible value is reached, or optionally continues in a parallel configuration of the stationary AND mobile capacitors (see excursus),

- Circuit diagram of the mobile capacitors, which is based on the patents mentioned above,

- Circuit diagram of the charging of the stationary capacitors

Electronics, which can be manifold and would not make a useful contribution here.

The sequence of the stepwise connection of the capacitors C1-C7 is described below. - The network of mobile capacitors is connected to terminal J1.

- First the switch S1 is pressed; this connects capacitor 1 to relay R8,

- then the switch S8 is pressed; thereby the capacitor 1 charges the mobile capacitors; the current that is flowing now decreases constantly and the applied voltage increases.

- If the current falls below a certain value, switch S8 is released, then switch S1 is released and the mobile capacitors are switched from serial to parallel.

- After about one second, switch S2 is pressed and the mobile capacitors are switched to serial. - Now switch S8 is pressed; now the two capacitors 1 and 2 connected in series charge the mobile capacitors.

- If the current falls below a certain value, switch S8 is released, then switch S2 is released and the mobile capacitors are switched from serial to parallel.

- After approx. One second the switch S3 is pressed and the mobile capacitors are switched to serial.

- Now switch S8 is pressed; now the serially connected capacitors 1, 2 and 3 charge the mobile capacitors.

- If the current falls below a certain value, switch S8 is released, then switch S3 is released and the mobile capacitors are switched from serial to parallel.

- After about one second, switch S4 is pressed and the mobile capacitors are switched to serial. - Now switch S8 is pressed; now the serially connected capacitors 1, 2, 3 and 4 charge the mobile capacitors.

- If the current falls below a certain value, switch S8 is released, then switch S4 is released and the mobile capacitors are switched from serial to parallel.

- After about one second, switch S5 is pressed and the mobile capacitors are switched to serial.

- Now switch S8 is pressed; now the serially connected capacitors 1, 2, 3, 4 and 5 charge the mobile capacitors.

- If the current falls below a certain value, switch S8 is released, then switch S5 is released and the mobile capacitors are switched from serial to parallel.

- After one second, switch S6 is pressed and the mobile capacitors are switched to serial.

- Now switch S8 is pressed; now the serially connected capacitors 1, 2, 3, 4, 5 and 6 charge the mobile capacitors.

- If the voltage on the mobile capacitors reaches the maximum permissible voltage, or if the current falls below a certain value, switch S8 is released, then switch S6 is released and the mobile capacitors are switched from serial to parallel.

- After one second the switch S7 is pressed and the mobile capacitors are switched to serial.

- Now switch S8 is pressed; now the serially connected capacitors 1, 2, 3, 4, 5, 6 and 7 charge the mobile capacitors.

If the voltage on the mobile capacitors reaches the maximum permissible voltage, the switch S8 is released, then the switch S7 is released and the mobile capacitors are switched from serial to parallel.

- After about one second, the mobile capacitors are switched to serial.

- The charging process is now complete and the mobile capacitors are disconnected from J1.

The expression "If the current falls below a certain value" requires an explanation:

If a fully charged capacitor of identical type "charges" an empty capacitor, the result is the current curve shown in the diagram of FIG. 2a. This course can be divided into three areas; First of all, a very strong current flows which can damage components (cables, control electronics, etc.). The invention described here is intended to prevent this, which is why the charging process should not take place in this area. b. A strong current flows for a period of time. c. After a certain point in time, there is only a little electricity flowing, and you would have to wait a long time for the charging process to complete. The charging process should not take place in this area.

This means that the charging process, figuratively speaking, takes place in the area between points A and B in the diagram shown in FIG. 2b.

A single sub-step should therefore cover the area shown in the diagram in FIG.

Several sub-steps in a row cover the areas shown in the diagram in Fig. 2d: During a partial charging step, i.e. when a switch S is pressed, current flows from the stationary to the mobile capacitors, which is continuously decreasing. Thus, its tip is at the beginning of a charging sub-step. So that this never exceeds a certain maximum value, in the above scheme, point A2 defines when B1 is reached. Thus, B1 represents the "certain value" mentioned above. This can be calculated or determined experimentally.

Thus, the device always works in the optimal range; maximum currents are never exceeded and the charging time is minimized.

The diodes Dl to D6 are used to simultaneously activate all the relays required, which switch the capacitor in question plus the "underlying" ones.

In the exemplary embodiment, the network of mobile capacitors consists of five capacitors. However, it can also consist of a group of several sub-groups of multiples of capacitors, which can be connected partly in parallel and partly in series for charging.

However, this then has the disadvantage that the charging process takes longer than if all the mobile capacitors are connected in series, but in practice it can have the advantage that, among other things, a higher degree of compatibility can be achieved between mobile and stationary capacitors or mobile capacitor networks, which are designed for special applications (with high voltage requirements), nevertheless from existing stationary ones Capacitor assemblies can still be loaded relatively quickly.

In general, it is advisable to first load a mobile, like a stationary capacitor network in series, and as soon as the voltage applied to the capacitors to be charged, which is still connected in series, approaches the maximum permissible nominal voltage, it is charged in parallel in a second phase.

There are many solutions for charging the stationary capacitors, such as switching power supplies or DC / DC converters (dc / dc step up or step down converters, aka buck converters). If a network of stationary capacitors consists of so many capacitors that, if they are connected in series, they have a maximum total nominal voltage of, for example, 240 volts, a rectifier can also be used between the mains supply and stationary capacitors, with access to the mains current at least as high It must be able to deliver a lot of electricity, as the stationary capacitors can maximally absorb, which is given by the total internal resistance of all affected components including the stationary capacitors. It should be noted that the voltage applied to the stationary capacitors increases constantly, while the flowing current decreases constantly. Here, too, "logical three-pole relays" are useful for better monitoring and optimal management, but they do not have to be used.

If you imagine loading a truck equipped with capacitors, aka supercapacitors, in a short time, the required amount of energy becomes it require that the individual components be selected and dimensioned accordingly, and that it is essential to load the supercapacitors of a truck gradually.

example

A model prototype was implemented to test the function of the invention. It consists of a stationary unit with stationary capacitors and a remote-controlled model car from the Carrera F150 brand. The stationary unit contains seven supercapacitors from the SPSCAP brand with 3kF each, the model car contains five supercapacitors from the SPSCAP brand with 150F each. The mobile capacitors are firmly soldered and connected in series. The stationary capacitors are connected analogously to the circuit diagram shown in the figure; For the sake of simplicity, only seven capacitors are shown in the circuit diagram. The manufacturer Carrera also supplies a rechargeable nickel-metal-hydride battery and recommends charging the battery for 90 minutes in order to be able to drive for 20 minutes.

The electronics of the model car were not changed in any way, except that those of the mobile capacitors were soldered onto the two feeding contacts, which originally came from the Ni-MH battery, and a switch was attached between them. This means that the model car can also be used in the original configuration. Test series confirm the manufacturer's information regarding charging time (90 minutes) and driving time (20 minutes).

So that the electronics of the model car can work according to the manufacturer's specifications A step-up DC / DC converter is used between the mobile capacitors and the electronics of the model car, which increases the voltage to 20 volts. Then a step-down DC / DC converter was used, which delivers 6 volts. A switch was installed between the DC / DC converters and the electronics of the model car. The test series showed that the model car powered by the capacitors drives 5 minutes with a charging time of 20 seconds. This efficiency was achieved without any particular optimization of the capacitive supply being undertaken. This means that the ratio of charging time to service life for capacitor operation is a comparison factor more than 65 better than for battery operation. With appropriate optimization, the comparison factor with supercapacitors currently available on the market could easily be doubled.

Current research results show that the capacitance of capacitors can be increased from the current 0.3F / cm ² to 4F / cm ² and in the near future to 11F / cm ² "(source Superdielectrics Ltd.). For the remote-controlled model car, this would mean that with 2 minutes of charging you could theoretically drive about 6.6 hours or about 18 hours, which would make the comparison factor at least another 3 to 7 times higher.

Claims

1. Charging unit with a number of stationary capacitors for charging mobile capacitors, which can be connected via a connection socket, characterized by switching devices for connecting a first capacitor to the mobile capacitors and for gradually connecting a further capacitor, the number and respective capacitance of the stationary capacitors compared to the mobile is bigger.

2. Charging unit according to claim 1, characterized by a relay between the stationary capacitor network and the connecting socket.

3. A method for charging mobile capacitors by means of a charging unit according to claim 1, characterized in that stationary capacitors are switched on step by step and between the individual steps the stationary capacitors are separated from the mobile capacitors and the respective capacitors are connected in parallel so that their voltage states are equalized can.