Automobile vehicle fast charging device

Abstract

The disclosure is directed to balancing equipment for a grid comprising: a grid input; a transformer comprising a first winding connected to the output of said grid input; a first inverter connected to said transformer; a system of batteries connected to said first inverter; a supervisory unit set up to activate said first inverter and to ensure the charging or discharging of said batteries when an imbalance is detected; and a second inverter connected at the input to said second winding of said transformer and at the output to at least one charging plug of an electric or hybrid vehicle; said supervisory unit being set up to activate said second inverter when a charging need is detected at said recharging plug and when the injection needs on the grid are lower than a threshold value.

Claims

1. A balancing equipment for a high-voltage or medium-voltage grid, the balancing equipment comprising: a grid input comprising protection devices for said grid and devices for measuring performance of said grid to detect balancing needs; a transformer comprising a first winding connected to an output of said grid input and configured to step down the voltage of said grid; a first inverter connected to a second winding of said transformer and configured to transform an AC voltage into a DC voltage; a system of batteries connected to said DC voltage; and a supervisory unit configured to activate said first inverter and to ensure charging or discharging of said batteries when an imbalance is measured on said grid by said measuring devices, wherein said balancing equipment further comprises a second inverter connected at the input to said second winding of said transformer and at the output to at least one charging plug of an electric or hybrid vehicle; and a detector configured to detect a charging need of said charging plug; and wherein said supervisory unit is configured to activate said second inverter when a charging need is detected at said charging plug and injection needs on the grid are lower than a threshold value.

2. The balancing equipment according to claim 1, wherein said detector for measuring the performance of said grid to detect balancing needs comprises an energy meter dedicated to a manager of said grid and an independent energy meter, said independent energy meter being configured to measure AC consumption sensed at the input of said second inverter.

3. The balancing equipment according to claim 1, wherein said detector for detecting a charging need of said charging plug corresponds to a probe for measuring a requested charging power on said charging plug.

4. The balancing equipment according to claim 1, wherein said balancing equipment comprises a probe disposed at the input of said first inverter to measure instantaneous power (Peq) in AC energy consumed by said system of batteries.

5. The balancing equipment according to claim 1, wherein said balancing equipment comprises a probe disposed on said DC voltage of said system of batteries to measure instantaneous power (Pbat) in DC energy consumed by said system of batteries.

6. The balancing equipment according to claim 1, wherein said balancing equipment comprises a probe set up at the input of said second inverter to measure instantaneous power (Pre) in AC energy consumed by said charging plug.

7. A method for managing the balancing equipment of claim 1, said method comprising: measuring a difference between a voltage measurement (mU), a frequency measurement (mF) and a current measurement (ml) of the grid and nominal values to determine the injection and/or withdrawal requirements (U, F, I); determining control power (Pc1, Pc2) of the second inverter connected to the system of batteries as a function of the injection and/or withdrawal requirements (T, F, C) of active and/or reactive power; if the injection requirements (T, F, C) are greater than a maximum injection power (Pmax), deactivation of the second inverter and activation of the first inverter connected to the system of batteries to inject said maximum injection power (Pmax), if the injection requirements (T, F, C) are lower than a maximum injection power (Pmax), deactivating the second inverter and activating the first inverter connected to the system of batteries to inject said control power (Pc1, Pc2), if the withdrawal requirements (T, F, C) are lower than a requested recharging power (Prrve) on said charging plug and charge level of the system of batteries is higher than a threshold value, deactivating the first inverter connected to a battery set and activating the second inverter to withdraw said control power (Pc1, Pc2), and if the withdrawal requirements (T, F, C) are greater than a requested recharging power (Prrve) at said recharging plug and the charge level of the set of batteries is less than a threshold value, activating the first inverter and the second inverter until the charge level of the system of batteries is higher than said threshold value.

8. The method according to claim 7, wherein the said control power (Pc1, Pc2) is determined as a function of load losses (Pe) estimated from measurements (Peq, Pre, Pbat) taken from three sensors respectively arranged at the input of the said first inverter, at the input of the said second inverter and on the said DC voltage of the said system of batteries.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The manner of carrying out the disclosure, as well as the advantages arising therefrom, will be evident from the following embodiments, which are given by way of an indication but not a limitation, to support FIGS. 1 to 6, which comprise:

(2) FIG. 1 is a schematic representation of state of the art battery balancing equipment;

(3) FIG. 2 is a schematic representation of a state of the art battery charging station;

(4) FIG. 3 is a schematic representation of a state of the art fast charging station;

(5) FIG. 4 is a schematic representation of a balancing equipment of the state of the art;

(6) FIG. 5 is a schematic representation of state of the art balancing equipment;

(7) FIG. 6 is a schematic representation of balancing equipment according to some embodiments of the disclosure, and

(8) FIG. 7 is a flowchart of the management steps of a supervising device of the balancing equipment in FIG. 6.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

(9) FIG. 6 illustrates balancing equipment 10 that is also a charging station for an electric or hybrid vehicle. This balancing equipment 10 typically comprises a grid input 11 incorporating protective devices 12 and measuring devices 13. The grid input 11 can be connected to the high-voltage or medium-voltage grid. For example, the input of grid 11 may be connected to two separate power cables each carrying 20 kV. In addition, the input of grid 11 may also include a grid output allowing one of the two cables to pass through the input of grid 11 to form a balancing device through which the grid passes.

(10) The protective devices 12 typically correspond to high-voltage or medium-voltage circuit breakers, for example controlled circuit breakers capable of disconnecting 400 A current to protect the balancing equipment 10. Preferably, the grid cables enter the input of grid 11 via manual circuit breakers allowing maintenance operations to be carried out in the balancing equipment 10. An automatic circuit breaker is preferably fitted to the output of these manual circuit breakers so as to cut off the current conducted through the input of grid 11 when the current withdrawal within the balancing equipment 10 is above a threshold value. It is preferable to couple these protective devices 12 with measuring devices 13 so as to detect the times at which the current through the input of grid 11 should be cut off.

(11) These measuring devices also measure the frequency, the voltage and the phase shift between the current and this voltage, all in order to detect the active and reactive power balancing needs of the grid. Preferably, these measuring devices 13 incorporate several energy meters: an energy meter associated with the grid operator and an independent energy meter associated with the operator of the balancing equipment 10. These energy meters are preferably connected to a wired or wireless communication network.

(12) In this way, the grid operator can obtain information about the balancing requirements in real time using the measurements made by the measuring devices 13 of the balancing equipment 10. Similarly, the measurements made by the independent energy meter can be transmitted to the operator of the balancing equipment 10 to control the amount of energy injected into or withdrawn from the grid.

(13) The measuring devices 13 transmit at least three items of information to a supervisory unit 22: a voltage measurement mU, a frequency measurement mF and a current measurement mI, the supervisory unit 22 being configured to calculate the phase shift between the current and the voltage. Alternatively, the measuring devices 13 may include means for automatically detecting the phase shift between voltage and current and this phase shift may be transmitted to the supervisory unit 22. The supervisory unit 22 can be a hardware processor or controller configured to execute specific computer-executable instructions to perform the functions discussed herein.

(14) The function of the supervisory unit 22 is to identify the balancing needs of the grid and to meet these needs according to the state of charge of the batteries 17 integrated in the balancing equipment 10. This supervisory unit 22 may be in the form of a microcontroller or a microprocessor associated with an instruction sequence. Furthermore, this supervisory unit 22 can be remotely controlled, for example by the operator of the balancing equipment 10, in order to update the balancing strategies or the charging authorisations of the electric or hybrid vehicles.

(15) To balance or charge an electric or hybrid vehicle, the input of grid 11 output is connected to a transformer 21c with at least two windings. The first winding is preferably delta-wired and receives the 20 kV grid voltage. This first winding is coupled to a second winding, preferably also delta-wired with a voltage stepped down to 450 V. The transformer 21c may also have a third winding for connecting measuring instruments, for example.

(16) The AC voltage, stepped down to 450 V, is connected to a first inverter 15c, which transforms the AC voltage into a DC voltage that supplies the system 16 of batteries 16. Preferably, the output of the first inverter 15c has a DC voltage level between 700 and 1000 V. The first inverter 15c also transforms the DC voltage of the system 16 of batteries 17 into AC voltage, therefore operating as a bi-directional inverter.

(17) In addition, the AC voltage stepped down to 450 V is also connected to a second inverter 23c, which in turn is connected to the charging plug 24 of an electric or hybrid vehicle. The second inverter 23c transforms the AC voltage, which has been stepped down to 450 V, into a DC voltage that supplies the charging plug 24. It is preferable for the output of the second inverter 23c to have a DC voltage level of 50 V. The second inverter 23c can also transform the DC voltage into AC voltage, for example to use the battery charge when needed to supply the grid, operating as a bidirectional inverter.

(18) In addition to these essential parts of the disclosure, others may be implemented to improve the safety or control strategies of the balancing equipment 10. For example, FIG. 6 illustrates sensors placed after the transformer 21c to measure power at different points in the balancing equipment 10. More specifically, a first probe is set up at the input of the first inverter 15c to measure the AC power Peq consumed by the system of batteries 17. A second probe is arranged at the input of the second inverter 23c to measure the power consumed Pre in AC energy by the charging plug 24. These two sensors, with the measuring device 13, make it possible to assess the losses related to the transformer 21c and to measure the reactive energy, e.g. the phase shift, applied by the first and second inverters 15c, 23c. This second probe can also transmit information about the amount of AC power consumed by the charging plugs 24 to an energy meter.

(19) A probe on the DC voltage of the system 16 of batteries 17 is used for measuring the instantaneous power Pbat in DC energy consumed by the system 16 of batteries 17.

(20) Working jointly with the first probe set up at the input of the first inverter 15c to measure the power Peq, the probe on the DC voltage of the 16 is used for assessing the losses related to the first inverter 15c.

(21) To adapt the balancing strategy of the two inverters 15c and 23c, it is simply necessary to detect consumption or, at least, presence at the charging plug 24 by means of a signal Ep, as shown in FIG. 6. Preferably, the charging power Prrve required by the charging plug 24 is measured by a probe set up at the charging plug 24 to provide information to the supervisory unit 22.

(22) Based on this information, the supervisory unit 22 can determine the strategy to be used by the inverters 15c and 23c.

(23) In addition to these structural items allowing an electric or hybrid vehicle to be charged and the grid to be balanced, the balancing equipment 10 may incorporate conventional parts of balancing equipment, such as a refrigeration unit for cooling the transformer 21c or the system of batteries 17, triggering an alarm or a fire protection unit, etc.

(24) FIG. 7 illustrates an example of the management process of the two inverters 15c and 23c implemented by the supervisory unit 22. In a first step 50, this method measures the difference between voltage mU, frequency mF and current mI and nominal values to detect the needs U, I, F of injection or withdrawal on the reactive and/or active power grid. If the difference between a nominal and measured value mU, mF, mI exceeds a threshold value, an injection or withdrawal requirement is determined on the basis of this difference. The second step 51 aims at determining the power to be applied to the first inverter 15c depending on the injection or withdrawal requirements Pc1 and a coefficient k. These requirements Pc1 are then specified in a second determination step 52 by taking into account the real losses at the transformer 21c. These real losses can be estimated by the different sensors depending on the state of the inverters 15c and 23c.

(25) The requirements Pc2 obtained on completion of step 52 can be applied according to several predefined scenarios, for example: if the injection needs U, F, I are greater than a maximum injection power Pmax, deactivating the second inverter 23c and activating the first inverter 15c connected to the system of batteries 17 to inject the maximum injection power Pmax, if the injection requirements U, F, I are lower than a maximum injection power Pmax, deactivating the second inverter 23c and activating the first inverter 15c connected to the system of batteries 17 to inject the control power Pc1 or Pc2, if the withdrawal requirements U, F, I are lower than a requested charging power Prrve on the charging plug 24 and the charge level of the system of batteries 17 is higher than a threshold value, deactivation of the first inverter 15c connected to the system of batteries 17 and activation of the second inverter 23c to withdraw the control power Pc1 or Pc2, and if the withdrawal requirements U, F, I are greater than a requested charging power Prrve at the charging plug 24 and the charge level of the battery set 17 is less than a threshold value, activating both inverters 15c, 23c until the charge level of the battery set 17 is greater than the threshold value.

(26) The disclosure thus makes it possible to obtain balancing equipment 10 which, in addition to balancing the grid, makes it possible to charge an electric or hybrid vehicle very quickly, since the balancing equipment is directly connected to the high-voltage or medium-voltage grid. The disclosure therefore offers a way of obtaining a fast charging station at a lower cost because it reuses existing components in the balancing equipment 10, particularly at the grid input 11. In addition, the disclosure also allows for the use of an easily-implemented transformer 21c and meter for the AC current consumed by the charging plug.