WO2014029420A1

WO2014029420A1 - Method for limiting electrical power consumption

Info

Publication number: WO2014029420A1
Application number: PCT/EP2012/066232
Authority: WO
Inventors: Martina FRIEDRICH
Original assignee: Siemens Aktiengesellschaft
Priority date: 2012-08-21
Filing date: 2012-08-21
Publication date: 2014-02-27

Abstract

The invention relates to a method for limiting the electrical power consumption of charging devices (1, 10, 20) for charging a traction battery (7, 17, 27) of an electrically driven vehicle (5, 15, 25). At least two charging devices (1, 10, 20) are each assigned a set point (S1, S2, S3), which describes the maximum electrical power which the respective charging device (1, 10, 20) can discharge to the vehicle (5, 15, 25). In the method, a prognostic value for the power consumption of the at least two charging devices (1, 10, 20) is determined (220) for a current time interval, the prognostic value is compared (230) with a predetermined maximum value and, if the prognostic value is greater than the maximum value, at least one of the set points is reduced.

Description

description

Electrically driven vehicles have a traction battery (accumulator) which provides the electrical energy required for the driving operation. Discharged batteries must be recharged if necessary by means of a charging device. Such a charging device emits electrical energy to the vehicle during the charging process, with which the traction battery of the vehicle is charged. This electrical energy takes the charger from a power grid. Contracts for the supply of electric power from energy ^¬ utilities often contain provisions which must not be exceeded during a specified time interval, Example ^¬, during a 15-minute time interval, a specified ^differently Bener maximum value of the energy absorption means.

European patent application EP 0 803 956 A2 discloses a method and a system for optimizing the consumption of electrical energy in industrial plants. The respective energy reference power is decentralized analy ^¬ Siert, based on decentralized calculations, suitable loads are selected and switched on or off.

The invention has for its object to provide a method and a device with which the electrical power consumption can be limited by charging devices.

This object is achieved by a method and a device according to the independent claims. Advantageous embodiments of the method and the Einrich ^¬ tion are given in the dependent claims. Is given According to the invention a method of limiting the electrical power consumption of charging means for charging a traction battery of an electrically driven vehicle, wherein at least two charging devices are each assigned a target value which ^¬ writes the electrical energy be, which must from ^¬ indicate the charging means at a maximum at the vehicle wherein in the method a prediction value for the energy absorption of at least two charging devices is determined for a currently running time interval, the prediction value is compared with a predetermined maximum value and when the predictive value is greater than the maximum value, Minim ^¬ reduces least one of the setpoints (reduced), where ^{¬ is} reduced by the energy consumption in the time interval. In this case, the predetermined maximum value is a maximum value of the average energy consumption for the time interval. In particular ^¬ sondere the maximum value describes the maximum allowed mitt ^¬ sized electric power consumption in the time interval.

In the method is particularly advantageous that - if the forecast value is greater than the maximum value - at least one of the setpoints is reduced. Thereby, the Minim ^¬ least an associated charging device is instructed to output less electric power to the vehicle in the current time interval. As a result, the energy consumption of the relevant charging station is reduced in the time interval, so that the average electrical energy consumption in the time interval is reduced. So that no more electrical Ener ^¬ energy is absorbed by the charge devices during the time interval, as dictated by the maximum value is ensured. As a result, penalties are avoided, for example, which can be agreed in energy supply contracts in the event that the maximum value is exceeded ^¬ . The process can proceed in such a way that at least the one

Setpoint is sent to the associated charging device. This informs the corresponding charging device of the changed setpoint. The method may be configured such that the forecast is ^¬ value determined using the already completed in the time interval energy intake, energy expenditure of the current would take at least two loading facilities and the length of the not yet elapsed time of the time interval. The current power consumption can be for example the energy ^¬ receptive at the time of the forecast. 'Date of the forecast, "the timing is understood in the time interval here at which the forecast value is determined. However, the refreshes ^¬ elle power consumption can also be a mean of Ener ^¬ gieaufnahme at the time of the forecast, so for example an average of the energy absorption during a up to the time point of the forecast ^¬ zoom reaching time range, wherein the time range is shorter than the time interval.

The method may be configured such that the maximum value is constant over time, or the maximum value from a data ^¬ memory is read out, stored in the time interval individual maximum values, or the maximum value of a charging device external unit is received. So there are several ways in which the maximum value is predetermined. The method may also be such that at least one of the setpoints is increased if the prediction value is less than the maximum value. This can malwert good use of prescribed Maxi ^¬. According to the invention, furthermore, a control device for limiting the electrical energy consumption of charging devices for charging a traction battery of an electrically driven vehicle, wherein at least two Ladeeinrichtun ^¬ gen each assigned a desired value, which describes the electrical energy, the charging device to the maximum

May give vehicle, the control device is configured to determine a forecast value for the Energieauf ^¬ measure the at least two charging devices for a current running time interval, comparing the prediction value with a maximum value and decreasing (reduce) at least one of the setpoint values if the forecast value than the Ma ^¬ is greater ximalwert. This reduces the energy consumption during the time interval. In this case the predetermined maximum value is a maximum value of the average power consumption for the Zeitin ^¬ interval. Specifically, the maximum value describes the maximum allowed average electric power consumption in the time interval ^¬.

This control device may be configured to transmit the at least one setpoint to the associated Ladeeinrich ^¬ device. The controller may be configured such that the control device determines the predictive value by using the already completed in the time interval energy consumption, the current power consumption of the at least two Ladeein ^¬ directions and the length of the not yet elapsed time span of the time interval.

The control device may be configured such that the maximum value is constant in time, or the maximum value is a maximum interval value which is stored in a data memory, or the maximum value has been received by a charger-external unit.

The control device may also be designed to increase at least one of the setpoint values if the prediction value is smaller than the maximum value.

This control device also has the advantages stated above in connection with the method. The invention will be explained in more detail below with reference to ^exemplary embodiments. This is in Figure 1 shows an embodiment of the method and the control device, in

Figure 2 is an exemplary process flow and in

FIG. 3 shows a further exemplary method sequence. FIG. 1 schematically shows a first charging device 1 which is electrically connected to a first electrically drivable vehicle 5 by means of a first charging cable 3. The first charging device 1 transmits electrical energy to the vehicle 5 via the first charging cable 3 in order to charge a first driving battery 7 of the first vehicle 5.

Also, a second charging device 10 is shown, the second means of a second charging cable 13 with a

electrically driven vehicle 15 is electrically connected, said vehicle 15 has a second drive battery 17 ^¬ . In the same way, a third charging device 20 is shown, which is electrically connected by means of a third charging cable 23 with a third electrically driven vehicle 25. The third vehicle 25 has a third driving battery 27.

The first charging device 1, the second charging device 10 and the third charging device 20 receive electrical energy from an energy supply network 24 via electrical supply lines 22 and return this electrical energy via the charging cable to the corresponding vehicles. The first charging device 1, the second charging device 10 and the third charging device 20 are connected to a control device 29 by means of a communication connection 27 (for example by means of communication lines or by means of a radio-communication connection). The control device receives information about the energy intake from the charging devices 1 via this communication connection 27, 10 and 20. Via this communication link 27, the control device 29 further sends setpoint values to the charging devices 1, 10 and 20. These setpoints describe the magnitude of the electrical energy which the charging device is allowed to deliver to the respective vehicle to be charged (eg the power P or the maximum) Energy W, which the charging device may deliver to the vehicle respectively). For example infor ^¬ mized the charging device, the connected vehicle according to the nominal value of the size of the electrical energy that may abfordern the vehicle from the charging device.

The controller 29 is also optionally connected via a further communication link 32 with the power supply network 24th Via this further communication connection 32, the control device 29 receives information from a control unit 33 of the energy supply network or

an operator of the power supply network 24. Furthermore, the control device 29 has a data memory 34. In the exemplary embodiment, it is contractually agreed between an operator of the three charging devices and a power supply company 24 that in each time interval, the energy consumption of the three charging devices may not be greater than 20 kW on average (the maximum value P _max is therefore 20 kW). In this case, the maximum value P _max is thus constant in time and stored as Kon ^¬ stante in the data memory 34 of the control device 29th In another embodiment, the maximum value depending ^¬ can also be read from a table yet, are stored in the zeitin- tervallindividuelle maximum values. This ^table can also be stored in the data memory 34. By means of a data query can then for each Zeitin- interval of the respective associated time interval individual Ma ^¬ ximalwert from the table of the data memory 34 are read out. In other words, for each time interval of the day (eg for each 15-minute time interval of the day, own its maximum ^¬ value stored in the table of the data memory 34 Thus, for each quarter hour of the day) a. In a further embodiment, the maximum value can also be received from a charging device external unit, for example by the control unit 33 of the energy supply company ^¬ disposed in the power supply network 24th This control unit 33 constitutes a ladeein ^¬ direction external unit, which can transmit the applicable Ma ^¬ ximalwert by means of a message 55 to the controller 29th

In the exemplary embodiment, the time-invariable maximum value P _max = 20 kW is assumed. The length of the time Inter ^¬ Valls is 15 minutes. With a maximum of 20 kW up to 5 kWh electrical ^¬ shear energy can be absorbed by the three chargers during this time interval. In the exemplary embodiment it is assumed that in 10 minutes have passed from the ak ^¬ tual 15-minute time interval, so that the length of the elapsed time is not the time interval 5 minutes ^¬ transmits be (1/12 hour).

The first charging device 1 is associated with a first setpoint value S1, which in the exemplary embodiment has the value 5 kW (Sl = 5 kW). This set value S1 specifies that the first charging device may deliver maximum electrical energy with the power 5 kW to the first vehicle 5. With walls ^¬ ren words, the first charging device 1 is instructed by means of this first target value Sl to give maximum electric energy to the power of 5 kW to the first vehicle. 5 The first charging device 1 ensures that the first vehicle 5 is not more than the first target value Sl entspre ^¬-reaching performance requests. This is done by means of a commu ^¬ communication between the first charging device and the first vehicle, which is not shown in the figures.

If the first vehicle abfordern 5 more power from the first La ^¬ signaling device 1, as the first target value corresponds Sl speaks, then the first charging device 1 automatically ends the charging process or reduces the charging power.

The second charging device 10 is assigned a second set value S2, which has the value 10 kW (S2 = 10 kW). By means of this second desired value, the second charging device 10 is instructed to deliver a maximum of electrical energy with the power 10 kW to the second vehicle 15. The third charging device 20 is assigned a third setpoint value S3, which in the exemplary embodiment has the size 15 kW (S3 = 15 kW). By means of this third target value is instructed, the third Ladeeinrich ^¬ tung 20 to deliver a maximum of electrical energy with the Leis ^¬ tung 15 kW at the third vehicle 25th By means of a first message 40 informs the first charging ^¬ device 10, the control device 29 about the fact that the first charging means a kilowatt-hour of energy in the last 10 minutes of the time interval (1 kWh) has received from the power grid 24 10, and that current electric energy with a power of 5 kW is recorded. Likewise, the second charging device 10 sends a second message 42 to the control device 29. With this second message 42, the control device 29 is informed that the second charging device 10 during the first 10 minutes of the time interval one kilowatt hour of energy (1 kWh) from the power grid 24th recorded and that the current power consumption is 10 kW. Also, the controller 29 is informed by means of a third message 44 that the third charging device 20 is a kilowatt ^¬ hour energy during the first 10 minutes of the interval (1 kWh) has received from the power grid 24 and that the current power consumption is 15 kW. Based on this, in the control device 29 vorlie ^¬ constricting data determined in the control device 29 is a forecasting sewert P _P for the power consumption of the three charging devices 1, 10 and 20 for the currently running time interval. The forecast value P _P for the time interval in which the loading unit average energy is calculated using the following formula:

P _P = (W + P t _R ) / T

Where P _P is the forecast value, W is the already taken up by the loading means during the time Inter ^¬ Valls energy ^¬ amount (ie, the previously ver ^¬ needed during the time interval power), P is the actual power consumed, t _R the length of the not yet elapsed time of the Time interval (remaining time) and T the length of the time interval.

With the above-mentioned values, the following forecast value results in the exemplary embodiment:

P _P = (Wl + W2 + PI + P2 t _R t _R + W3 + P3 t _R) / T

P _P = (1kWh + 5kW (l / 12) h + 1kWh + 10kW (l / 12) h + 1kWh +

15kW (l / 12) h) / 0,25h

P _P = (1,417kWh + 1,833kWh + 2,25kWh) / 0,25h = 22kW

Thus, the forecast value P _{P of} the average electrical power consumption of the 22 kW charging devices is greater than the predetermined maximum value P _max = 20 kW. For this reason, the controller 29 reduces at least one of the target values of the three charging devices to limit the electric power consumption of the charging devices.

According to the relation PI + P2 + P3 = (P _P T - Wl - W2 - W3) / t _R , the controller determines that, during the time elapsed t _{R of} the time interval, the outputs _P 1, _P 2 and _P 3 of the charging means together add the value 24 kW may not exceed. In comparison with the previous ones

Setpoints Sl = 5 kW, S2 = 10 kW and S3 = 15 kW, the controller 29 determines that these setpoints must be reduced by a total of 6 kW. In the exemplary embodiment, the control device 29 reduces the first reference value Sl of 5 kW to 4 kW and sends by means of a fourth message 46 to new setpoint Sl = 4 kW at the first charging device 1. Then, the first charging ^¬ device 1 reduces its electric power supply to the first Vehicle 5 such that the first vehicle 5 is charged only with a power of 4 kW. Furthermore, the control device 29 reduces the second

Setpoint S2 of 10 kW to 8 kW and sends by means of a five ^¬ th message 48 to new setpoint S2 = 8 kW to the second charging device 10. Subsequently, the second charging device 10 reduces its electric power supply to the second vehicle 15 so that the second vehicle 15 is only charged with a power of 8 kW.

Furthermore, the controller 29 reduces the third reference value S3 of 15 kW to 12 kW and sends by means of a sixth message 50 to new setpoint S3 = 12 kW to the third La ^¬ signaling device 20. Thereafter, the third charging device 20 reduces its electric power supply to the third vehicle 25 such that the third vehicle 25 is charged only with a power of 12 kW.

29 Subsequently, the control means calculates a new predictive value for the power consumption of the three Ladeeinrichtun ^¬ gen: P = _P (Wl + W2 + PI + P2 t _R t _R + W3 + P3 t _R) / T

P _P = (1kWh + 4kW (l / 12) h + 1kWh + 8kW (l / 12) h + 1kWh + 12kW (l / 12) h) / 0,25h

P _P = (1,33kWh + 1,67kWh + 2kWh) / 0,25h = 20kW. This results in a new forecast value P _P for the mean electrical power consumption in the time interval. This new performance prediction value P _P states that the three Ladeein ^¬ directions exactly in the time interval on average, the maximum allowed to take up 20 kW of electrical power. Thus, the forecast value P _{P is} equal to the predetermined maximum value P _max = 20 kW. A further reduction of the setpoints is therefore not necessary. Now the sequence repeats, ie the control device receives current data of the three charging devices and calculates another prognosis value. The ^¬ He mediation the forecast value is repeated cyclically. The time between two forecast value calculations can be specified via a configuration. Likewise, parameters (such as dead times or hystereses) can be preset via a configuration in order to prevent unwanted oscillations of the setpoints.

In the previously described examples of the prognosis value has not been accounted occurring defects ^¬ trend in charging devices power loss when determining development. In another embodiment, this power loss could be also taken into account by a value for the occurring in the charging device power dissipation is added when determining the prognosis ^¬ value to the target values for each charging station.

In a further exemplary embodiment, the method can also run such that the setpoint values are reduced stepwise until the prediction value is less than or equal to the maximum value.

In another embodiment, the method may also occur so that the controller 29 only the third reference value S3 of 15 kW to 9 kW, and the reduced at ^¬ the two reference values can be unchanged. This case may occur, for example, when the first vehicle and the second vehicle have a higher priority when loading than the third vehicle. The reduction of the setpoint values can therefore depend on a priority of the customer or of the vehicle connected to the charging station during charging. Thereafter, the control device 29 sends the new setpoint value S3 = 9 kW to the third charging device 20. deeinrichtung 20 their electrical energy output to the third vehicle 25 such that the vehicle 25 is charged only with a power of 9 kW. The controller 29 then calculates a new forecast value P _P:

P _P = (Wl + W2 + PI + P2 t _R t _R + W3 + P3 t _R) / T

P _P = (1kWh + 5kW (l / 12) h + 1kWh + 10kW (l / 12) h + 1kWh + 9kW

(l / 12) h) / 0.25h

P _P = (1.42kWh + 1.83kWh + 1.75kWh) / 0.25h = 20kW

The value of the predicted average electrical power in the time interval is thus P _P = 20kW and thus corresponds to the maximum value P _ma x. In FIG. 2, the method described is represented once again by means of a flowchart. For a start time (block 210) is known how big the ^¬ interval already made energy intake is in the current time, what is the current energy consumption of chargers (this corresponds to the nominal values) and how large the not verstri ^¬ chene period of the time interval (the remaining time) is. ^¬ at these values, a prediction value for the Energieauf ^¬ exception of said loading means is in the current time interval is determined (block 220). Thereafter, the determined prognosis value is compared with a predetermined maximum value (block

230). If the forecast value is less than or equal to the maximum value, then the process flow is tergeführt at block 220 wei ^¬, ie it is determined, a new forecast value (with aktua ^¬ ized data). However, if the prediction value is greater than the allowable maximum value, then the Ver ^¬ drive control flow goes to block 240. Then, at least one desired value for the charging devices is decreased (reduced), whereby the energy absorption of the respective charging device or charging devices is reduced. This setpoint is then transmitted to the relevant charging device or the relevant charging devices (block 250). Thereafter, the process continues at block 220. FIG. 3 shows a further exemplary method sequence. This variant provides that at least one of the setpoints is increased if the forecast value is smaller than the maximum value. This allows the maximum value to be used well. In this case, either - similar to that described above in connection with the reduction of the target values in detail - are calculated by the control device, to what value the reference value or more setpoints are in the lau ^¬ fenden time interval to increase. Alternatively, the target value or target values can be gradually while ver ^¬ enlarges until the forecast value is equal to the maximum value. By means of dead times and / or hystereses, unwanted oscillations of the setpoints can also be prevented here. In the embodiment of Figure 3, is checked ge ^¬ in block 310 whether the predictive value is smaller than the maximum value. If so, then at least one setpoint is increased in block 320. Thereupon, the Minim ^¬ least received an enlarged set value to the charging device or the loading devices in block 330th Thereafter, the process continues at block 220.

A method and a control device have been described with which the electrical energy consumption of charging devices can be effectively limited. This ensures that during a time interval not more electrical energy is taken from the loading facilities on ^¬, as dictated by a maximum value.

Claims

claims

1. A method for limiting the electrical energy consumption of charging devices (1, 10, 20) for charging a Fahrbatte- rie (7, 17, 27) of an electrically driven vehicle (5, 15, 25), wherein at least two charging devices (1, 10 , 20) in each case a desired value (S1, S2, S3) is assigned, which describes the electrical energy, which may deliver the respective Ladeein ^¬ direction (1, 10, 20) maximum to the vehicle (5, 15, 25) , wherein in the process

a prognosis value for the energy consumption of the at least two charging devices (1, 10, 20) is determined (220) for a running time interval,

- comparing the forecast value with a predetermined maximum value (230), and

- if the prediction value is larger than the maximum value, min ^¬ least one of the command values is reduced (240).

2. The method according to claim 1,

d a d u r c h e c e n c i n e s that

- At least one setpoint (Sl) to the associated charging ^{device ¬} (1) is sent (46).

3. The method according to claim 1 or 2,

d a d u r c h e c e n c i n e s that

- the forecast value is determined (220) using the already completed in the time interval energy consumption, the ak ^¬ tual energy intake and length of not verstri ^¬ rupted period of time interval.

4. Method according to one of the preceding claims, characterized in that

- the maximum value is constant in time, or

- is read out of the maximum value from a data memory (34) are vomit ^¬ chert in the time interval individual maximum values, or

the maximum value is received by a charger external unit (33).

5. The method according to any one of the preceding claims, d a d u r c h e c e n e c e in that e

- if the prediction value is smaller than the maximum value, control for at least one of the reference values is increased (320).

6. Control device (29) for limiting the electrical energy consumption of charging devices (1, 10, 20) for charging a traction battery (7, 17, 27) of an electrically driven vehicle (5, 15, 25), wherein at least two Ladeeinrichtun ^¬ conditions ( 1, 10, 20) in each case a desired value (S1, S2, S3) is assigned, which describes the electrical energy, which deliver the jewei ^¬ lige charging device (1, 10, 20) maximum to the vehicle (5, 15, 25) may, with the control device is configured to the

Determining (220) a forecast value for the energy consumption of the at least two charging devices (1, 10, 20) for a running time interval,

Comparing (230) the forecast value with a maximum value and

- reducing (240) at least one of the setpoint values if the prediction value is larger than the maximum value.

7. Control device according to claim 6,

d a d u r c h e c e n c i n e s that

the control device is designed for

- Sending (46) of the at least one desired value (Sl) to the ^¬ ordered charging device (1).

8. Control device according to claim 6 or 7,

d a d u r c h e c e n c i n e s that

- The controller determines the prognosis value (220) un ^¬ ter use of the already in the time interval energy intake, the current energy consumption and the length of the not yet elapsed time period of the time interval.

9. Control device according to one of claims 6 to 8, characterized in that - the maximum value is constant in time, or

- The maximum value is a time interval individual maximum value stored in a data memory (34), or

- the maximum value has been received by a charger external unit (33).

10. Control device according to one of claims 6 to 9, d a d u r c h e c e n e c i n e s that the control device is designed to

- increasing (320) of at least one of the setpoint values if the prediction value is smaller than the maximum value.