DE102009040586B4 - Adaptive hybrid control - Google Patents

Abstract

A method for influencing the charging capacity of an electrical energy storage device of a hybrid vehicle, the charge level (SOC) is computer-controlled by supplying electrically storable braking energy and is lowered by removing electrical energy for the operation of one of several vehicle-own consumers, characterized in that the hybrid vehicle on a same Travel route is used, and that the vehicle computer along the route electrically used and electrically unused braking energy is determined and also this data sections (Sv-C) are assigned and stored, where the hybrid vehicle is braked at full energy storage without storage, the Degree of charge (SOC) of the energy storage before reaching a section of track (S1-C), in which a high braking power is obtained at each run of the route by removing electrical energy is further lowered, so that the Energiespe Ier is adaptively prepared for receiving electrically storable braking energy, and wherein the removal of electrical energy from the energy storage before a section on which the electrically storable energy is insufficient to charge the energy storage to a required extent, is adaptively reduced.

Description

The invention relates to a method for influencing the charging capacity of an electrical energy store according to the preamble of claim 1.

From the DE 38 10 340 A1 a motor vehicle is known, in particular a truck or bus, the drive motor is associated with a device for pushing engagement of secondary consumers. From the engine power to a drive train and power take-offs can be delivered to connectable ancillaries to load energy storage of secondary consumers. An electronic control device detects a change of the internal combustion engine from train operation to overrun due to introduced operating state signals. As soon as it is determined that a coasting operation is present, one or more vehicle-internal drive units are selectively switched on in the drive train. The connection takes place in a specific order of precedence, which is determined in a priority selection circuit, which results from supply necessities and is determined in a target / actual comparison.

The disadvantage, however, is that such vehicles must have a navigation system that includes a digital map in which the planned route is deposited. Planned turns and stopping points of the vehicle must be taken into account. Furthermore, it has been found that in certain energy storage high discharges have a negative effect on the life of the memory. A further disadvantage is that the behavior of the control can be influenced in particular by the height profile of the planned route. Moreover, it has been found that in certain energy storage high discharges have a negative effect on the life of the memory.

From the DE 10 2007 020 196 A1 a method for controlling the state of charge of an energy storage device for a vehicle with hybrid drive is known in which a vehicle speed value of the vehicle is detected and a desired state of charge of the energy storage device in dependence on the vehicle speed value is determined. Likewise, an actual state of charge of the energy store is detected and the actual state of charge is compared with the desired state of charge. By means of a state of charge controller, a connection of an energy consumer to at least partial discharge of the energy store is made when the actual state of charge is exceeded via the desired state of charge.

It is therefore an object of the invention to provide a method for charging and discharging an energy storage, which always maintains sufficient charge capacity of the energy storage in order to provide an optimally sufficient charge capacity of the energy storage, without adversely affecting the life of the energy storage. Under load capacity is in this context to understand the capacity of the energy storage.

The object is achieved by the features of claim 1.

According to the invention, the method is used in a commercial vehicle, in particular a bus, which has a hybrid drive, with an electric motor being available as drive units in addition to an internal combustion engine. Furthermore, the method is based on a bus, for example, in regular service, but it is also conceivable to use the method according to the invention in another commercial vehicle, which fulfills the features of patent claim 1 (eg street sweepers or refuse collection vehicles). In the omnibus according to the invention, the required drive power and the resulting braking power along the route is detected. It is noted how much braking energy accumulates in which sections and whether sufficient energy storage capacity is available in the energy storage to recuperate the accumulated braking energy and store. In the present context, the energy storage device can be any storage medium which is suitable for storing and releasing energy in a motor vehicle. In addition, the method is related to an electrical energy storage and converted into electrical energy braking energy. However, it is also applicable to any other type of recuperation and energy storage in which data is collected along the route. The correspondingly required data records are collected and stored by a computer present in the vehicle. When driving down the predominantly same route, it is therefore detected in which route sections driving energy is required and in which areas of the route electrically storable braking energy is generated and how much. In addition, it is noted whether the electrical energy storage against the background of its respective charge capacity is in each case able to absorb and store the resulting electrical braking energy. When the route is repeatedly traveled, the electrical energy store is discharged more deeply than the route sections in which accumulated braking energy could not be stored to the desired extent in the form of electrical energy, compared to the degree of charge of the previous navigation of this route section. The aim is to be able to absorb more braking energy in the following route section. The degree of charge refers to the amount of energy stored in relation to the maximum storage capacity at a given time. When driving off continuously The route is taken from the electrical energy storage energy and supplied to at least one on-vehicle consumers as drive energy. Each time around the route, the energy storage based on the data collected by the computer from previous route points at which brake energy accumulates, but could not be fully absorbed due to low charging capacity of the energy storage, discharged more deeply. In order to successively be able to absorb more braking energy in the form of electrical energy in the memory, the degree of charge of the energy store as well as the recuperated braking energy and the non-recuperated braking energy are detected and stored locally. In this way, the charging capacity of the energy storage adaptive and anticipatory adapted to the resulting braking energy. The charge capacity of the electrical energy store of the type is adapted to each section of the road, in which braking energy accumulates, so that sufficient charging capacity is available in order to be able to completely store any accumulating braking energy that can be converted into electrical energy. Conversely, the adaptive discharge of the electrical energy store is successively reduced as soon as the energy store at the subsequent route points has not been charged to the required extent in the event of a previous departure of the route section. The energy storage is therefore not discharged to the same extent to the extent that the resulting braking energy can be stored in each case in full. Rather, the required load capacity only occurs in the course of several passes of the predominantly same route before the route sections with high braking energy. Each time the route is traveled, the operation of the hybrid powertrain and the vehicle's own consumer to adjust the desired charge capacity of the energy storage adapted to the changed conditions. The electrical energy storage is to be unloaded before route sections with high braking energy to the extent that the braking energy can be stored to the desired extent in the form of electrical energy. The inventive method ensures that no recuperable energy is lost and thus can be used to save fuel. The energy storage does not have to be discharged as a precaution, especially deep, but is adaptively discharged as far as the situation requires. The life of the energy storage can thus be extended considerably. In the adaptive specification of the charge level of the energy storage device before road sections in which brake energy accumulates, a predetermined cost function can additionally be taken into account. The cost function assesses the saving of fuel costs compared to the life of the energy storage device with high recuperation and reduces the degree of adaptation at high braking energy.

According to further embodiments of the invention, the degree of charge is adaptively lowered at each run of the route in response to the determined electrically unused braking energy. In addition, it is conceivable that the removal of electrical energy from the energy store is adaptively reduced with each departure of the travel route depending on the determined usable braking energy.

For this purpose, the adaptation of the charge level in a charge profile can be assigned to the route sections of the travel route and the associated determined brake energy. For specified times of the day, week and / or calendar days special charge profile can be created.

It is conceivable that the vehicle-own consumers are a drive motor of the vehicle and / or at least one additional accessory. In this connection, the braking energy exceeding the charging capacity can be used without storage for the operation of the drive motor and / or of the auxiliary unit. In sections where drive power is required, the ancillaries are driven with reduced supply of electrically usable braking energy. As a result, less stored braking energy is taken from the energy store. In such sections, in which braking energy accumulates, the ancillaries can be driven with increased supply of electrically usable energy. In the adaptive increase or decrease of the charge level of the energy storage, the required for the control of the drive motor and / or the at least one auxiliary unit electrical energy is taken into account. The adaptive increase or decrease in the degree of charge is additionally influenced by the holder of the energy storage by high charge or discharge cycles. It is also conceivable that the adaptive increase or decrease of the charge level is performed against the background of a cost function, which takes into account the cost of additional fuel consumption due to unused braking energy and the cost of cycle-related aging of the energy storage. The adaptive increase or decrease in the degree of charge is carried out as a function of the maximum filling limit of the energy store.

The position of the hybrid vehicle on the route is determined based on defined start and stop points by integration of at least one speed signal and / or a wheel speed signal. In general, the position of the hybrid vehicle on the route can be determined by satellite positioning.

As ancillaries, for example, an air conditioner, the heating or the bus interior lighting can be operated. According to the ancillary units are fuel-efficient and driven by resorting to the convertible into electrical energy braking energy. In those route sections in which the route profile of the route requires increased drive power of the engine, the auxiliary device according to the invention is driven to a lesser extent by energy removal from the energy store. The ancillaries are therefore preferably driven in such route sections by converted braking energy, in which the accumulated braking energy can not be supplied to the electrical energy storage in full or due to the cost function of the energy storage is not to be supplied in full.

The adaptation of the charge level of the energy store is determined as a function of the braking energy to be expected according to the prestored route profile. Due to the continuous driving on a guideway, the associated charging and discharging profile of the energy store along the guideway is determined and used for the operation of the plurality of vehicle-own consumers according to a predetermined order of priority. High power peaks interrupted by periods of downtime of the vehicle's own consumers can thus be effectively avoided. The inventive method leads to a gradual adaptation of the charge capacity of the energy storage. Each time the route is bypassed, the loading capacity is either increased or decreased. According to the method but also the constancy of the load capacity during the passage of the route is conceivable.

Several charge profiles of the energy storage can be determined and stored along the route by the vehicle computer. This is advantageous if the driving operation is strongly influenced by the time of day or the respective day of the week, for example by typical vehicle loads or daytime or day-typical traffic flows. For different time periods of the day and / or different days of the week, the respectively required charge profiles can be selected and combined. Different load profiles can also be provided for holidays with reduced passenger volume. The vehicle position can be determined on the respective route based on defined start and stop points by a corresponding route measurement in the vehicle. This can, for. B. by angular momentum counting or integration of speed signals. Typical starting and stopping points of a route can z. B. the exit from the depot, intermediate and final stops of a bus line.

It is also conceivable to use the braking energy, which exceeds the charging capacity, directly for the operation of an auxiliary unit. The excess braking energy can thus either the drive motor of the bus or one or more other vehicle units are provided as drive energy. This is conceivable in particular in those situations in which, due to high expected braking energy, the energy store has to be discharged at a preceding route point for receiving the expected braking energy to the extent that this is detrimental to the life of the energy store. A direct operation of the consumer would also be conceivable and useful if at a route point so much braking energy would arise that the maximum available charging capacity of the energy storage above the minimum charge level (SOC-min) would not be sufficient to accommodate the available braking energy. The operation according to the method of the vehicle's own consumer, for example an air conditioning compressor or the air pressure supply, can be converted directly into drive energy, especially in the route sections with a high proportion of excess braking energy, bypassing the energy store. A part of the braking energy can thus be supplied directly to the consumer, if the currently available charging capacity of the electrical energy storage no longer allows recording electrically storable braking energy. The resulting from a braking braking energy can be used directly for the drive of the vehicle's own consumer, whereby the fuel consumption of the commercial vehicle can be additionally lowered.

Further advantageous embodiments and expedient developments of the method according to the invention are apparent from the following example descriptions with reference to the drawing.

• 1 die Ladekapazität eines elektrischen Energiespeichers vor abschließender Anpassung durch das erfindungsgemäße Verfahren und
• 2 die Ladekapazität eines elektrischen Energiespeichers nach der Anpassung durch das erfindungsgemäße Verfahren.

Hereby show:

• 1 the charge capacity of an electrical energy storage before final adaptation by the inventive method and
• 2 the charge capacity of an electrical energy store after the adaptation by the method according to the invention.

1 shows on the ordinate from top to bottom first the degree of charge ( SOC ) of the electrical energy store over a route ( s ). Including the associated speed ( V ) of the bus over the route ( s ) and below again the route profile with the overcome height difference ( H ) over the route ( s ).

In the representation of the degree of charge ( SOC ) a maximum degree of charge ( SOC max ), which indicates the maximum charge level of the energy store. A minimal degree of charge ( SOC min ) designates that degree of charge of the energy store beyond which the energy store may not be discharged. In 1 is about the route ( s ) the height ( H ) of the route profile. On the route ( s ) are each a stop ( A ), a stop ( B ), a route point ( s1 ) as well as a stop ( C ). The route point ( s1 ) follows a longer braking range. The before the stop ( A ) route point is in the areas ( 1 ) and ( 2 ). On the route ( s ) in the direction of travel behind the stop ( A ) is followed by another area ( 3 ). The areas ( 1 ) and ( 2 ) in front of the bus stop ( A ) each run at a constant height level. In the area ( 2 ) the driver of the bus initiates the braking process and brings the bus to the bus stop ( A ) to stand. The speed is reduced from an assumed average speed ( v ) to 0 at the stop ( A ). In the example of 1 is in the field ( 1 ) The electrical energy storage discharged so far that sufficient charge capacity is available to absorb the electrically storable braking energy can. According to the 1 overcomes the omnibus in the route section between the stop ( A ) and the bus stop ( B ) a considerable difference in altitude ( H ) to then on a route section of constant height ( H ) to the station ( B ) to drive. In the route section between the stop ( A ) and the bus stop ( B ) the bus increases after leaving the bus stop ( A ) the speed, then at constant speed over the aforementioned route profile to the stop ( B ) to drive. Just before reaching the stop ( B ) the bus slows down its speed to stop at the bus stop ( B ) to come to a standstill. With regard to the degree of charge of the energy store, the energy store is started up in the area (FIG. 3 ) Energy taken to accelerate the vehicle. Would the vehicle in the sequence in a plane (not shown) drive, so the degree of charge of the energy storage would not be lowered, since only kinetic braking energy would be incurred and this completely absorbed by the energy storage after the acceleration of the bus by energy removal from the energy storage could be. The kinetic energy is the energy that the inventive hybrid vehicle contains due to its motion. In the data collection with previous passage of the route has been determined that starting from the route point (s), a route with such high braking energy begins that before this section of the load capacity must be increased, because from the route point ( SV ) the energy storage was completely filled and additional braking energy could not be stored (see. 1 ). The high proportion of braking energy in comparison to the other sections falls in the section ( S1 ) to ( C ), because the bus travels on a slope at which the vehicle is braked and then at the stop ( C ) must be stopped. The adaptive method takes the energy store in the section before the route point ( s1 ) more electrically stored energy each time the route passes through, S1 ) to ( C ) no electrically storable braking energy remains unsaved. At the in 1 shown state, the adaptation is not yet completed, so that even brake energy is lost. The energy extraction before the route point ( s1 ) takes place in such a way that the bus is operated as economically as possible. In 1 gets off the bus after starting the bus ( A ) The energy store further taken energy. The energy extraction is used for example to relieve the engine in hybrid operation when driving uphill between the stop ( A ) and the bus stop ( B ). Also conceivable is the omnibus in partial load operation in front of the bus stop ( B ) without internal combustion engine to drive purely electrically, or to supply ancillary components while driving uphill from the energy storage out. The type of storage energy utilization is determined according to the criteria of economic operation, the amount of stored energy taken up to the route point ( s1 ) is given adaptive according to the invention. The adaptation process recognizes that before reaching the stop ( C ) Braking energy ( Ev ) remains unsaved and therefore increases the energy extraction before the route point ( s1 ), at which the track starts with a comparatively high amount of braking energy. The extent of the increase in the energy extraction, for example, proportionally depending on the previously determined and not stored braking energy ( Ev ) respectively.

2 shows the same route as 1 However, after further passing through, so that due to the adaptation method according to the invention from the route point ( s1 ) accumulated braking energy can be absorbed by the energy storage, because before the route point ( s1 ) a corresponding amount of electrically storable energy has been taken from the memory.

Claims (16)

Method for influencing the charging capacity of an electric energy storage device of a hybrid vehicle, whose charge level (SOC) is increased by computer control by supplying electrically storable braking energy and which is lowered by removal of electrical energy for the operation of one of a plurality of in-vehicle consumers, characterized in that the hybrid vehicle is used on a same route, and that the vehicle computer along the route electrically used and electrically unused braking energy is determined and also this data road sections (Sv-C) are assigned and stored, where the hybrid vehicle is braked at full energy storage without storage on wherein the charge level (SOC) of the energy storage before reaching a section (S1-C), in which a high braking power, is further reduced by removing electrical energy at each run of the route, so that the energy storage for receiving electrically storable braking energy adaptive is prepared, and wherein the removal of electrical energy from the energy storage before a link section at which the electrically storable energy is insufficient to charge the energy storage to a required extent, is adaptively reduced. Method according to Claim 1 , characterized in that the degree of charge is lowered adaptively at each run of the route in dependence of the determined electrically unused braking energy. Method according to Claim 1 or 2 , characterized in that the removal of electrical energy from the energy storage is adaptively reduced at each run of the route as a function of the determined usable braking energy. Method according to one of the preceding claims, characterized in that the adaptation of the degree of charge in a charge degree profile of the route sections of the route and the associated determined braking energy is assigned. Method according to one of the preceding claims, characterized in that special charge profile profiles are created for specified times of the day. Method according to one of the preceding claims, characterized in that specific charge degree profiles are created for specified weekly or calendar days. Method according to one of the preceding claims, characterized in that the vehicle's own consumers are a drive motor of the vehicle and / or at least one further auxiliary unit. Method according to one of the preceding claims, characterized in that the charge capacity exceeding braking energy is used without storage for the operation of a drive motor and / or an auxiliary unit. Method according to Claim 7 , characterized in that the ancillaries are driven at distances in which drive power is required, with reduced power and that the ancillaries are driven in sections in which braking energy accumulates, with increased supply of electrically usable braking energy. Method according to Claim 7 , characterized in that in the adaptive increase or decrease of the charge level of the energy storage, the required for the control of the drive motor and / or the at least one auxiliary unit electrical energy is taken into account. Method according to one of the preceding claims, characterized in that in the adaptive increase or decrease of the degree of charge, the aging of the energy storage is taken into account by high charging or discharging cycles. Method according to Claim 11 , characterized in that the adaptive increase or decrease of the charge level is influenced by a cost function that takes into account the cost of additional fuel consumption due to unused braking energy and the cost of cycle-related aging of the energy storage. Method according to one of the preceding claims, characterized in that in the adaptive increase or decrease of the charge level, a maximum filling limit of the energy storage is taken into account. Method according to one of the preceding claims, characterized in that the position of the hybrid vehicle is determined on the route from defined start and stop points by integration of at least one speed signal. Method according to one of the preceding claims, characterized in that the position of the hybrid vehicle is determined on the route from defined start and stop points by integrating at least one wheel speed signal. Method according to one of the preceding claims, characterized in that the position of the hybrid vehicle on the route is determined by satellite-based location.

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