IL263462B - Method and system for managing automatically the energy stored by an electric vehicle - Google Patents

Description

1 METHOD AND SYSTEM FOR MANAGING AUTOMATICALLY THE ENERGY STORED BY AN ELECTRIC VEHICLE The present invention relates to a method and a system for automatically managing the energy stored by an electric vehicle, in particular a rolling transport system with stored energy, such as a tram, bus or the like.

Trams or electric buses are currently designed with stored energy, stored in an appropriate energy storage system (such as batteries, supercapacitors, etc.) so as to be able to circulate, fully autonomously, on an interstation, i.e., between two charging stations.

The energy stored by the energy storage system is consumed either in the form of traction energy (to bring the tram to a certain speed, keep it at a cruising speed, or bring it to a certain altitude), or in the form of comfort energy (i.e., the energy used by auxiliary devices on board the tram and making it possible to provide a certain level of comfort to passengers, for example lighting devices, heating devices, etc.).

Energy storage systems are currently dimensioned, in the nominal mode, to be able to transport, with a normal thermal comfort, the maximum passenger load over the interstation of the line that is most penalizing in terms of traction energy; and in the downgraded mode (corresponding to an outage of a recharge station), to be able to transport, with a reduced thermal comfort, the maximum passenger load over two successive interstations without recharging the storage system at the intermediate recharging station.

For example, the energy storage system of a tram can store a maximum energy of 13.5 kW.

Rolling transport systems with stored electrical energy have many advantages (less infrastructure on the ground for the railway field, ability to recover braking energy, etc.), but have a specific risk of failure by exhaustion of the stored energy before reaching a recharging station, also called a risk of "fuel exhaustion".

Currently, load shedding strategies for the comfort energy and/or traction energy are implemented to preserve the autonomy of the electric vehicle when the stored energy remaining in the energy storage system drops below a predefined critical threshold.

These strategies are predetermined. They therefore lack robustness, in that they do not incorporate the hazards inherent to use, such as slowdowns in traffic, or even untimely stops (at pedestrian crosswalks or intersections, for example). These predetermined strategies can therefore come up short under normal operating conditions.2 Furthermore, these strategies are defined based on worst-case scenarios, which may lead to them being implemented when there is no real need, whereas the operating conditions (passenger load, weather conditions, etc.) are no longer the most penalizing.

The aim of the invention is therefore to resolve this problem, in particular by proposing a system and method that are capable of managing the energy consumption of the transport system, in particular by adjusting its speed, to anticipate and avoid the occurrence of such a critical situation, and to make it possible to reach the next recharging station autonomously, both as quickly as possible and under the best comfort conditions for the passengers.

To that end, the invention relates to a method for automatically managing the energy stored by an electric vehicle for a transport mission over an interstation between a departure recharge station and an arrival recharge station, including the following steps: providing predetermined characteristics relative to the mission, the predetermined characteristics comprising a reference speed profile over segments subdividing the interstation; evaluating a current position and speed of the electric vehicle; estimating a cruising speed of the electric vehicle over the segments remaining to be traveled, based on the reference speed profile, the current speed and the current position; calculating a total anticipated energy as estimate of the energy to be consumed to reach the arrival recharge station, based on the current position, estimated cruising speeds and an auxiliary power supplied to auxiliary comfort devices of the passengers of the electric vehicle; determining an available stored energy as energy stored by an energy storage system of the electric vehicle in the current position; and displaying, on a screen, the total anticipated energy and the available stored energy.

According to specific embodiments, the method includes one or more of the following features, considered alone or according to any technically possible combinations: - the method includes a step for comparing the available stored energy and total anticipated energy, and, when the total anticipated energy is greater than the available stored energy, a step for identifying a speed - auxiliary power optimum making it possible to reach the arrival station. - the speed - auxiliary power optimum is identified so as first to make it possible to reach the arrival station, then to reach the arrival station at a predetermined arrival time, and lastly to reach the arrival station with a predetermined comfort level. - the speed-auxiliary power optimum is displayed on the screen. - the speed-auxiliary power optimum is applied as input to a system for regulating the speed and/or a system for regulating the auxiliary power.3 - the calculation of the total anticipated energy is done by providing a cruising speed on each segment of the interstation remaining to be traveled and by providing a current auxiliary power supplied to the auxiliary comfort devices for the passengers as auxiliary power on the segments of the interstation remaining to be traveled and by providing a travel time for the segments of the interstation remaining to be traveled. - the calculation of the total anticipated energy is further done by using an altitude profile over the segments of the interstation remaining to be traveled. - the forecast of the auxiliary power is done by using the travel time and an averaged measurement of the auxiliary power. - the calculation of the total anticipated energy is further done by using the anticipated cruising speeds and speed deviations, by differentiating between accelerations and decelerations of the electric vehicle. - the calculation of the stored available energy is done from an energy stored by the storage system at the current moment, from which a reserve energy is subtracted, defined as the energy needed to cross the following intersection.

The invention also relates to a system for automatically managing energy stored by an electric vehicle, the system being stored on board the electric vehicle, characterized in that it is capable of carrying out the preceding method.

The invention and its advantages will be better understood upon reading the following detailed description of one particular embodiment, provided solely as a non­ limiting example, this description being done in reference to the appended drawings, in which: - figure 1 is a schematic illustration of the system according to the invention equipping a tram; - figure 2 is a block diagram of the method according to the invention implemented by the system of figure 1; - figure 3 shows one possible cabin display of the relevant information delivered during the implementation of the method of figure 2; and - figure 4 shows various reference curves for the calculation of a speed - auxiliary power optimum in a total anticipated power versus input speed coordinate system.

The method for automatically managing energy stored by an electric vehicle in order to guarantee the performance of its mission is based on the calculation of a total anticipated energy, denoted Emis-prev, defined as an estimate of the energy that it will be necessary to supply in order to finish the mission. This estimate is done from the current position of the vehicle and is updated periodically during the movement of the vehicle.4 While the mission of the vehicle consists of transporting passengers over an interstation, from a departure recharge station to an arrival recharge station, "finishing its mission" refers to the ability of a vehicle to reach the arrival recharge station, or according to a nominal operating mode, consisting of reaching the arrival station within an allotted time and with a predefined passenger comfort level, or according to a downgraded operating mode, consisting of reaching the arrival station within a longer time and/or with reduced passenger comfort.

The total anticipated energy Emis-prev is then compared periodically to a stored available energy Eemb-dis, which corresponds to a stored energy Eemb from which a reserve energy Eres is subtracted. The stored energy Eemb is the energy stored in the energy storage system of the electric vehicle, advantageously reevaluated periodically based on the advance of the vehicle and the time elapsed since departure. The reserve energy Eres corresponds to the energy making it possible to cross the following interstation in case of malfunction of the recharge system of the arrival station.

Comparing these two energies, Emis-prev and Eemb-dis, allows a periodic evaluation of the autonomy of the electric vehicle, i.e., its ability to finish its mission. This makes it possible to manage the energy consumption of the electric vehicle appropriately, in particular by adjusting the movement speed of the electric vehicle and/or the auxiliary power supply of the auxiliary devices.

In particular, when the total anticipated energy Emis-prev exceeds the stored available energy Eemb-dis, the method advantageously provides for automatically determining an optimal operating point in terms of speed - auxiliary power. This optimal operating point is proposed to the driver or automatically applied as inputs to the system for regulating the speed and/or the system for regulating the auxiliary power.

Hereinafter, as shown in figure 1, the invention will be more particularly described for an electric vehicle of the tram type 2, equipped with an energy storage system, for example batteries 4. Alternatively, other types of storage system may be considered, in particular supercapacitors.

The batteries 4 make it possible to supply electrical power to a traction motor 6, as well as a power converter 8 for the auxiliary devices.

The tram 2 is equipped with a system 10 capable of carrying out the method for automatically managing stored energy according to the invention.

The system 10 includes a logic controller 12, which is a computer capable of carrying out the instructions of a computer program.5 From raw input data that it receives on its input/output interface from various peripherals, the logic controller 12 is capable of computing various input data of the method according to the invention. This input data is for example and preferably: - the stored energy Eemb, which corresponds to the energy stored by the batteries 4 at the current moment; - the position X of the tram along the considered interstation; - the speed V of the tram; - the mass M of the tram; - the auxiliary power Paux of the auxiliary devices at the current moment; - the location of the current interstation.

More specifically, the stored energy Eemb is for example measured using an appropriate sensor 24 associated with the batteries 4.

The position X is the instantaneous position of the tram 2 between the two departure and arrival stations defining the ends of the interstation. It corresponds to the distance traveled from the departure station. The position X is for example determined from odometrical means 22 equipping the tram 2, in particular a phonic wheel making it possible to measure the distance traveled from the departure station, taken as origin.

The current speed V is the average over several seconds, for example three seconds, of the instantaneous speed supplied for example by the odometrical means 22, in particular a tachometer capable of measuring the instantaneous speed of the tram 2.

The mass M is for example the value supplied at the moment when the tram leaves the departure station by the braking substation 23 of the tram 2, which is capable of determining the mas from signals delivered by appropriate charge sensors. The mass M therefore accounts for the number of passengers on board the tram 2.

The auxiliary power Paux is for example determined by the maximum value, over a window of several minutes, for example six minutes (characteristic cycling time of the auxiliary air conditioning devices), of the average over several seconds, for example ten seconds, of the instantaneous auxiliary power consumed at the considered moment by all of the auxiliary devices on board the tram, in particular the air conditioning and heating devices of the tram cars for passenger comfort. The instantaneous auxiliary power is for example measured by an appropriate power sensor 28 equipping the converter 8.

The location of the current interstation is obtained by querying a ground control system by the logic controller 12 when stopping in a station. This is for example done via a wireless link established by a radio communication module 29 equipping the tram 2.6 The location thus obtained allows the querying by the logic controller 12 of a database on board the tram, to determine the characteristics of the mission on the current interstation.

It in particular involves the distance D separating the end stations of the interstation, reference speeds Vref-i on each segment (indexed by the integer i) of the various segments subdividing the interstation, and an altitude profile. The altitude profile is for example a discretized diagram of the altitude Z as a function of the position X, preferably including only the beginning of gradient change and end of gradient change points.

These characteristics also include the reserve energy Eres to be anticipated so as, in case of malfunction of the recharging system of the arrival station, to allow the tram to reach the following recharge station.

The system delivers, as output, a plurality of output data, for example and preferably: - a total anticipated energy Emis-prev(X) while the tram is in position X, corresponding to an estimate of the energy it is expected to consume to complete its mission from position X; - an available stored energy Eemb-dis(X), resulting from the difference between the stored energy Eemb(X) and the reserve energy Eres; - a real-time diagnosis of the ability to finish the mission, based on the comparison between the total anticipated energy Emis-prev(X) and the available stored energy Eemb-dis(X); - an auxiliary power input Paux*; - a speed input V*.

All or some of the output data are displayed on a screen 30 located in the cabin in order to inform the driver 3 of the tram and help him carry out the appropriate actions.

Preferably, all or some of the output data are sent to a control module 36 of the traction motor 6 and/or to a control module 38 of the converter 8.

The method 100 for automatically managing the stored energy will now be described in reference to figure 2.

In step 110, while the tram 2 is stopped at the departure station, it collects the characteristics of the mission on the interstation. The characteristics of the interstation are communicated to the logic controller 12 via the ground-on board link and the radio communication module 29.

Then, while the tram 2 moves over the interstation between the departure and arrival stations, the following steps are iterated periodically.

In step 120, the logic controller 12 determines the position X relative to the departure station and measures the time t elapsed since the departure from the departure station.7 In step 130, the logic controller 12 estimates an auxiliary power Paux, a cruising speed Vcrois-i for each segment i on the end of the interstation, and a time T to finish the mission and reach the arrival station.

For example, in step 132, the logic controller 12 determines the auxiliary power Paux from the measurement delivered by the sensor 28, as indicated above.

In step 134, the computer 12 determines the speed V from the measurement delivered by the system 22, as indicated above.

In step 135, it compares the speed V determined at the current moment to the reference speed Vref for the segment of the intersection on which the tram is engaged.

It interprets a small deviation between the speed V and the reference speed Vref-i over the current segment i as a small disruption and anticipates an immediate return from the speed V to the reference speed Vref-i. The cruising speed Vcrois-i is therefore considered to be equal to the speed Vref-i, not only over the current segment i but also over the following segments i+1, I+2, etc.

It interprets a large deviation between the speed V and the reference speed Vref as a sign of traffic disrupted by a hazard and anticipates the continuation of the movement of the tram at this reduced speed V over the end of the segment. The cruising speed Vc is therefore considered to be equal to the speed V.

Lastly, if the speed V is nil, it is advantageously provided to use, during the restarting of the tram after the stop, a cruising speed equal to the cruising speed before the stop.

More specifically, the logic controller 12 can advantageously manage an unforeseen stop (for example at a pedestrian crosswalk or at an intersection). To that end, the logic controller 12 then stores the cruising speed before the stop and anticipates restarting at said cruising speed. Thus, when the tram restarts, the stored cruising speed is taken into account during a predetermined duration to implement the method, which may depend on the acceleration time needed to reach said cruising speed. Once the restart is finished, the system 10 bases itself again on the measured speed V to provide a new cruising speed. In this way, during the acceleration phase, it is possible to obtain a reasonable evaluation of the kinetic energy needed to finish the mission, the cruising speed used being a priori the reference speed and not the low speed of the tram when it leaves the stop.

In step 136, the logic controller 12 bases itself on the results of step 135 to provide the cruising speeds Vcrois-i on the following segments of the interstation, up to the arrival station.

If, in step 135, a small deviation has been observed, the logic controller 12 considers that, over the following i segments, the input speed Vci of the tram will be the reference speed Vrefi associated with each of said segments.8 If, conversely, in step 135, a large deviation has been observed, the logic controller 12 considers that, over the following i segments, the cruising speed Vcrois-i initially provided will be reduced relative to the reference speed Vref-i associated with each of said following segments.

In step 138, the computer 12 uses the cruising speeds Vci on the current segment and the following segments, as well as the lengths of said segments, to provide the duration T of the mission.

Then, in step 140, the logic controller 12 estimates the total anticipated energy Emis- prev(X0), which is the energy that must be expected to need to be consumed to finish the mission, while the tram is in position X0.

The total anticipated energy Emis-prev is calculated as the sum of a traction energy Etrac and an auxiliary energy Eaux.

The traction energy includes a kinetic energy component Ecin (corresponding to the traction energy to be supplied to bring the vehicle to a certain speed), a potential energy component Epot (corresponding to the energy to be supplied to bring the vehicle to a certain altitude) and a friction component Efrot (corresponding to the energy to be supplied to overcome the resistance to forward motion).

The auxiliary energy corresponds to the energy to be supplied to the passenger comfort auxiliary devices.

For these estimates, the computer 12 uses the results of step 130 (Paux, Vcrois-1, Vcrois-2, Vcrois-3, ... and T) and step 120 (X, t) as well as the characteristics of the interstation (length of the interstation, altitude profile).

For example, the anticipated kinetic energy is calculated with the mass of the vehicle and the cruising speeds Vcrois-i anticipated to finish the mission. Furthermore, this calculation incorporates the speed deviations between the the various segments and the traction phases during an acceleration, or braking during a deceleration (advantageously with recuperation of the braking energy). This calculation of the anticipated kinetic energy distinguishes, by a negative or positive sign, the contributions of these phases, considers a yield of the traction and a yield of the braking in case of electric braking. Advantageously, the absence of recuperation of braking is taken into account below a threshold speed, which is for example equal to 13 km/h, below which threshold the braking is mechanical by necessity and no longer electrical.

For example, the duration T anticipated to finish the mission multiplied by the auxiliary power Paux makes it possible to obtain the anticipated auxiliary energy to be provided to finish the mission.9 Also for example, the frictional energy is taken into account as a fixed quantity per interstation and allocated on a prorated basis as a function of the forward motion. This simplification is compatible with the necessary precision in the case of trams. The friction component can be calculated with a more specific model for resistance to forward motion using any transport system with stored energy.

The total anticipated energy Emis-prev calculated at point X0 is that necessary for the end of the mission. It is updated periodically to account for the forward motion of the vehicle.

Upon each update, it is compared directly to the available stored energy Eemb-dis, which is also updated periodically to account for the energy actually consumed to arrive at the current point. This calculating and comparison mechanism naturally recalibrates the total energy necessary for the mission as the amount of energy that has already been consumed and the energy remaining to be supplied to finish the mission.

Alternatively, step 140 is inhibited in the first five to ten seconds following a startup, for the time needed to allow the tram to accelerate to reach a stabilized speed that can be used as a cruising speed. This makes it possible to limit the risk of over-evaluating the total anticipated energy Emis-prev(X).

Advantageously, the logic controller 12 incorporates appropriate energy yields into each of the energy estimates. For example, to provide a useful kinetic energy of 1 kWh, it will be necessary for the motor 6 to consume an energy of 1.08 kWh, taking account of a traction performance of 0.82, which corresponds to a stored energy of 1.13 kWh, in the case of an energy yield of 0.95 of the batteries 4.

If the electrical losses are taken into account in this way, the mechanical losses are taken into account through the frictional energy, which encompasses all forms of mechanical and aerodynamic resistance to the forward motion of the tram.

Fixed yields are considered for each type of energy transformation, which is compatible with the necessary anticipation precision for the energy necessary to establish a forecast for the end of the mission.

The method 100 includes a step 144 for determining the available stored energy Eemb-dis (X). This energy is the difference between the stored energy Eemb(X) and the reserve energy Eres.

The stored energy Eemb(X) is preferably updated periodically. It comes from the measurement delivered by the sensor 24 at the current moment. Alternatively, it can be reconstituted by calculation based on the forward motion along the interstation.

The autonomy condition of the tram generally being defined on two successive interstations, a reserve energy Eres is reserved to allow restarting from the arrival station and the exceptional continuation of the movement of the tram without recharging at the10 arrival station, up to the next recharge station. Thus, the tram 2 will be capable of linking two interstations without recharging, in case of complete failure of the recharging at the arrival station. This means that the tram must reach the arrival station without having consumed this reserve energy.

In step 146, the information that has just been calculated is displayed in the cabin on the screen 30. For example, as illustrated in figure 3, the screen displays a gauge 200 indicating, by a first moving symbol 210, the total anticipated energy Emis-prev(X) and, by a second symbol 220, the stored available energy Eemb-dis(X), relative to the level 230 of the reserve energy Eres.

In step 150, the logic controller 12 establishes an energy diagnosis by comparison between the total anticipated energy Emis-prev(X) and the stored available energy Eemb-dis(X).

If the stored available energy Eemb-dis(X) is greater than the energy needed at the end of the mission Emis-prev(X), this means that the batteries 4 are storing enough energy to finish the mission, with the current state in terms of cruising speed and auxiliary power.

Steps 120 to 146 are iterated (loop 101), leading to the update of the values of Emis- prev(X) and Eemb-dis(X).

If the total available stored energy Emis-prev(X) is less than or equal to the energy necessary to finish the total anticipated mission Emis-prev(X), this means that the energy stored by the batteries 4 is insufficient to finish the mission with the current state.

Thus, in the case of a diagnosis indicating a lack of autonomy, the method 100 continues with a step 160 for identifying a speed - auxiliary power pair making it possible to finish the mission.

During step 160, the logic controller 12 carries out an optimization algorithm making it possible to identify, in real time, a speed - auxiliary power optimum.

Thus optimum is a compromise. Indeed, a higher cruising speed claims more traction energy to achieve this speed, but saves comfort energy by shortening the duration of the end of the interstation and therefore the usage time of the auxiliary devices.

Conversely, a lower cruising speed claims less traction energy, but increases the duration to reach the arrival station and therefore more comfort energy, unless the auxiliary power is reduced.

In the embodiment currently considered, the following constraints are successively implemented: The first constraint is to have the tram perform its passenger transport mission by reaching the arrival station. It is therefore necessary for the total anticipated energy to be less than the available energy.11 The second constraint is for the mission to be carried out in the allotted time, for example according to a tram traffic timetable. Thus, a reduction in cruising speed will be recommended only when mandatory. In other words, it is provided to reduce the auxiliary energy and only to reduce the traction energy if the reduction in auxiliary energy does not make it possible to complete the mission.

The third constraint is to reduce the auxiliary energy in a manner seeking to limit the impact on thermal and visual comfort experienced by passengers. Thus, load shedding of the auxiliary devices is only recommended when it becomes mandatory to save stored energy so as to reach the arrival station autonomously.

The optimum operating point that makes it possible to reach the arrival station as quickly as possible and with the best possible comfort level is selected.

In one possible embodiment, different reference curves are first calculated, like those shown in figure 4. Each curve provides the total anticipated energy Emis-prev(X) as a function of the input speed Vc for a given value of the auxiliary power Paux. These curves are obtained by calculations similar to those shown above to estimate the total anticipated energy.

Then, iteratively, a total anticipated energy is calculated with an auxiliary power having a level below the current level. To that end, the logic controller has a load shedding table indicating the different auxiliary power discrete levels, between a nominal power and a minimum power.

If this reduction in auxiliary power allows a new positive energy diagnostic, then the logic controller 12 leaves step 160.

If, however, this is not the case, the following iteration of the calculation of the total anticipated energy is done with a cruising speed reduced by an increment of 5 km/h for example.

If this reduction of the cruising speed allows a new positive energy diagnostic, the logic controller leaves step 160.

If, however, this is not the case, the calculation is iterated.

Depending on the weight of the constraints previously described, it is possible to link two or three pitches of the calculation by decreasing the auxiliary power level before initiating a reduction pitch of the cruising speed.

Thus, in figure 4, to arrive at the next station, the optimum must lead to a total anticipated energy lower than the available energy (first constraint). If the energy Eemb-disp is MJ, this energy does not make it possible to reach the following station with the maximum auxiliary power of 112 kW, regardless of the speed; it makes it possible to do so with an auxiliary power reduced to 65 kW for a speed range between 35 and 13 km/h, or with an12 auxiliary power reduced to 30 kW for a speed range between 43 and 10 km/h. If the arrival time at the arrival station requires an optimal cruising speed of 37 km/h (second constraint), then it is necessary for the auxiliary power to be established at 30 kW (third constraint).

An optimum C(Vc*, Paux*) is thus determined as output of step 160.

This optimum corresponds to speed Vc* and auxiliary power Paux* inputs.

In step 170, these inputs are displayed as recommendations on the screen 30 to inform the driver 3. The driver carries out the recommended actions if he wishes, in particular taking into account other operating parameters of his vehicle.

Alternatively, these inputs are sent to appropriate systems of the tram to be taken into account automatically.

Thus, a control module 36 can filter the acceleration commands from the driver and limit his speed to the speed input or recommend that he accelerate if his speed is too slow.

Alternatively, the control module 36 regulates the motor directly from the speed input Vc* to modify the instantaneous speed of the tram. A control module for managing auxiliary devices will regulate the instantaneous power supply of said devices from the auxiliary power input Paux*, in particular by sending power limitation inputs to the various auxiliary devices, which may go up to a stop input.

These inputs are updated in real-time based on the advance of the train. To that end, steps 120 to 170 of the method are iterated (loop 102).

In step 180, the logic controller 12 advantageously detects the arrival in a station owing to the tracking of its advance along the interstation and the detection of a nil speed.

The computer 12 verifies that the recharge provided at the arrival station is effective, for example owing to the evolution of the measurement of the energy stored by the batteries 4.

If so, the logic controller 12 stops the load shedding of the auxiliary devices if such load shedding has been initiated, and re-initializes the speed inputs.

Steps 110 to 180 are carried out again (loop 103) on the following interstation.

On the contrary, if the logic controller 12 detects a stop at a station and an absence of effective recharge, it updates the total provisional energy as a function of the need on the new interstation and alters the calculation of the stored available energy, including the reserve energy therein, which it expects to use for this scenario.

In one alternative embodiment, instead of measuring the stored energy, it is considered to calculate it using the same calculation principles as those of the total anticipated energy. This alternative may advantageously offset imprecisions in the measurement of the energy stored by the energy storage system.13 In a second embodiment, the calculation of the speed-auxiliary power optimum may be done with a specific prioritization, depending on the operator's preferences, for example comfort first and travel time second.

In an alternative where the tram is able to recover the energy during braking, this recovered energy can be stored in the batteries, and the recovered energy is taken into account in determining the available stored energy.

This recovered energy can be used directly to power the auxiliary devices. The recovered energy is then taken into account in estimating the total anticipated energy Emis- prev(X).

These calculations will be done taking into account the recuperation performance of this braking energy, as well as the performance of the traction part and the performance of the storage part and taking into account the absence of recuperation below a threshold speed that is for example equal to 13 km/h.1/3 29 2 28 38 36 3 23 6 M 24 222/3 130 101 100 103 102 -180-3/3 200 210 E emb_dis 220 E mis_prev 230 E res E (X) [MJ] mis_prev ,0 P =112kw aux 18,0 16,0 P =65kw aux 14,0 P =30kw aux 12,0 E emb_dis ,0 8,0 C(V* ,P* ) c aux 6,0 4,0 2,0 0,0 0 10 20 30 40 50 60 V [km/h] c14

Claims (8)

1. A method (100) for managing automatically the energy stored by a tramway (2) for a transport mission over an interstation between a departure recharge station and an arrival recharge station, including the following steps: - providing (110) predetermined characteristics relative to the mission, the predetermined characteristics comprising a reference speed profile; - evaluating (132, 134) a current position and speed of the tramway ; - estimating (135, 136) a cruising speed of the tramway over the segments remaining to be traveled, based on the reference speed profile, the current speed and the current position; - calculating (140) a total anticipated energy (E ) as an estimate of the energy mis-prev to be consumed to reach the arrival recharge station, based on the current position, the estimated cruising speed and an auxiliary power (P ) supplied to auxiliary passenger aux comfort devices of the tramway ; - determining (144) an available stored energy (E ) as energy stored by an emb-dis energy storage system (4) of the tramway in the current position; - displaying (150), on a screen (30), the total anticipated energy and the available stored energy; - comparing (160) the available stored energy (Eemb-dis) and total anticipated energy (E ), and, mis-prev - when the total anticipated energy is greater than the available stored energy, a step (170) for identifying a speed – auxiliary power optimum making it possible to reach the arrival station, the speed – auxiliary power optimum being identified so as first to make it possible to reach the arrival station, then to reach the arrival station at a predetermined arrival time, and lastly to reach the arrival station with a predetermined comfort level.

2. The method according to claim 1, wherein the speed-auxiliary power optimum is applied as input to a system for regulating the speed and/or a system for regulating the auxiliary power.

3. The method according to any one of claims 1 to 2, wherein the interstation is made up of a plurality of segments and the calculation of the total anticipated energy (E mis- ) is done by providing a cruising speed on each segment (i) of the interstation remaining prev to be traveled and by providing a current auxiliary power (P ) supplied to the auxiliary aux passenger comfort devices as auxiliary power on the segments of the interstation remaining 15 to be traveled and by providing a travel time for the segments of the interstation remaining to be traveled.

4. The method according to any one of claims 1 to 3, wherein the calculation of the total anticipated energy (E ) is further done by using an altitude profile over the mis-prev segments of the interstation remaining to be traveled.

5. The method according to claim 3, wherein the forecast of the auxiliary power is done by using the travel time and an averaged measurement of the auxiliary power.

6. The method according to claim 3 or 4, wherein the calculation of the total anticipated energy (E ) is further done by using the anticipated cruising speeds and mis-prev speed deviations, by differentiating between accelerations and decelerations of the tramway.

7. The method according to any one of claims 1 to 6, wherein the calculation of the stored available energy (E ) is done from an energy stored by the storage system emb-disp at the current moment, from which a reserve energy is subtracted, defined as the energy needed to cross the following intersection.

8. A system (10) for automatically managing energy stored by a tramway (2), the system being stored on board the tramway, characterized in that it is capable of carrying out the method according to any one of claims 1 to 7.