DE102017203852A1 - Method for unbalanced load limiting and unbalanced load limiting unit - Google Patents

Abstract

A method for unbalanced load during the charging of an energy storage of one or more vehicles, wherein the vehicles are connected to one or more charging points of a charging cluster. The method comprises: determining a number of phases loaded at one or more charging points of the charging clusters, determining a single-phase charging at one or more charging points, determining a two-phase charging at one or more charging points, determining the respective phases that are in the non-three-phase Load charging, creating a charging plan for each of the one or more vehicles, based on the determined number of phases and / or the single-phase loaded phases.

Description

The invention relates to a method for unbalanced load limiting according to the preamble of claim 1 and a Schieflastbegrenzungseinheit.

The energy storage of an electric vehicle is usually charged to a charging device. At such a charging device, several electric vehicles can be connected simultaneously to charge their energy storage. At the connection point of the charging device to the power grid can then occur a unbalanced load. It is known to monitor the load at the connection point with a load management system. When an overload occurs, the charging power for the electric vehicles is reduced so that a predetermined maximum value is not exceeded at the connection point.

It is an object of the present invention to provide an improved method for unbalanced load limiting and an improved unbalanced load limiting unit.

The achievement of the object of the invention is achieved by the features of the independent claims. Advantageous developments of the invention will become apparent from the dependent claims.

The invention is based on the following knowledge: When charging several non-three-phase charging electric vehicles to a charging cluster, the situation may arise that the connection point of the charging cluster is charged to the power grid unbalanced. Such a charging cluster is for example a fleet loading device with several charging points for connecting electric vehicles. In the prior art, a reactive limitation of the charging power to individual charging points or the entire fleet charging device is provided when an overload is detected at the connection point. The charging power is then reduced so that a predetermined maximum value is not exceeded.

Such a reactive limitation of the charging power does not take into account the unbalanced load, which is predetermined by a network operator, for example, but only a predetermined maximum value for the load at the connection point of the charging cluster. Compliance with a maximum unbalanced load, for example, of 4.6 kVA can not be guaranteed. In known load management systems, each vehicle is assumed to be a three-phase charging vehicle, which may result in load management interventions in the form of limiting charging power at the respective charging point, although this would not be necessary.

The inventive measures a method for unbalanced load during charging of an energy storage of one or more vehicles is specified, the vehicles are connected to one or more charging points of a charging cluster. The method comprises: determining a number of phases loaded at one or more charging points of the charging cluster, determining non-three-phase charging at one or more charging points, determining the respective phases charged in non-three-phase charging, creating a charging schedule for each of them one or more vehicles based on the determined number of phases and / or the loaded phases.

A charging cluster has several charging points connected at a common reference point in terms of power cap and unbalanced load. In addition to charging points, a charging cluster can also contain control functions. These can be arranged both in a separate unit, as well as in a charging point or in a backend.

A charging point is a charging device for charging a single electric or plug-in hybrid vehicle (all statements regarding electric vehicles relating to the invention also apply to plug-in hybrid vehicles and vice versa). The charging point is in the context of this invention set up so that it can be addressed via communication means and set by interaction with the connected vehicle a predetermined charging power.

The inventive method for unbalanced load limiting an energy and load management is specified, which due to the determined number of used in an individual vehicle, such as an electric vehicle, phases and not three-phase charging, with knowledge of the determined loaded phases, a charging plan for each at the charging point or connected to the charging cluster vehicle created. This has the advantage that a predetermined maximum unbalanced load of a charging infrastructure with multiple charging clusters behind a connection point, for example, the connection point to a power grid, for example, 4.6 kVA can be ensured. The predetermined unbalanced load limit may be specified by a network operator or by an operator of the charging cluster or may be specified in other ways. By connection point to the network is meant the point of connection of the charging cluster to the electrical energy supply network.

The number of phases charged at one or more charging points of the charging cluster is determined by measuring the charging power during an initialization phase on the charging cycle Start of charging via meter or power meter determined. The measured values can be used to determine the number of loaded or used phases. Furthermore, the phase connections of the individual charging points (assignment of the power-transmitting contacts to the phases of the connection point) can be stored in a database, so that the information on which connection phase is loaded, for example, in single-phase charging already exists. In a later repeated single-phase charging for charging the energy storage of the vehicle, the information of the connection phase can be used directly from the database and a re-determination of the connection phase can be omitted.

The loading plan includes the specification of a maximum charging power over a given or calculated period of time. It is created for each vehicle whose energy storage is to be charged. The charging schedule of each vehicle includes a load default (power demand) for the current time or a load schedule for the presence of the vehicle at the charging point while its energy store is being charged. For example, load limits on one or more vehicles reactively limit the unbalanced load at the connection point to a value. In load planning for one or more vehicles, an anticipated unbalanced load is preventively prevented. The charging plan for each individual vehicle can be implemented in various ways: As a power specification by means of communication to a charging point, which is set up to limit the charging power, possibly in conjunction with the vehicle. Or by communication with the vehicle, which itself implements the power limitation (eg use ISO15118 ).

A further advantageous development of the method provides that the determination of the non-three-phase charging comprises: enabling an initial charging power per phase at the respective charging point, comparing the predetermined charging power with the charging power assumed by the vehicle, determining a non-three-phase charging if the vehicle adopted Charging power is below a threshold value, or determining a two-phase charging, if the charging power assumed by the vehicle is below a further threshold value, storing the determined type of charge and the loaded phase.

For determining the non-three-phase charging process and the charged phases of the charging process, a charging signal or charging instruction is first released to the vehicle for charging via the charging point and the reaction of the vehicle to it is evaluated. From this it is determined whether single-phase or multi-phase charging is present. Furthermore, the number of loaded phases is also determined. The charging requirement may be, for example, three times the minimum charging power. This can be done via a charge control of the charging cluster. In the process, this assigned charging power is evenly distributed at the charging point to all three phases, the same value being allocated evenly per phase. The actual power consumed by the vehicle is determined with a measuring device at the charging point on the basis of the measured power values and compared with the given charging power. If the power consumed is below a threshold below the total enabled power for the three phases, single-phase charging is detected. If the power consumed is below another threshold, two-phase charging is detected.

This has the advantage that it can be detected whether charging at the charging point is single-phase, two-phase or three-phase. The charging mode determined for the current charging process, ie single-phase or multi-phase charging, as well as the assignment to the claimed mains connection phase are stored and can be used directly for the creation of the charging plan. Furthermore, the determination as to whether single-phase or multi-phase charging is present can also be determined by stored knowledge, for example in a database. This knowledge includes the type of charge, vehicle-specific data or user request. By storing the determined type of charge, the renewed determination of the charging mode can be omitted in a future charging of the energy storage of the vehicle.

In an advantageous development, the method provides that a maximum charging power is determined during the charging process, comprising: enabling a maximum charging power at the respective charging point, comparing the predetermined maximum charging power with the power assumed by the vehicle, and storing the power consumed by the vehicle as the maximum charging power this vehicle.

In an advantageous further development, the method provides that a reduction or increase in the charging power for charging the energy store by one or more vehicles leads to a reduction in the unbalanced load, whereby the charging power of individual vehicles is reduced or increased at a connection phase.

When a vehicle is connected to the charging cluster, initially there is no information about the vehicle or the user of the vehicle. Only the configuration of the charging cluster is known: connected load to the power grid, number of charging points, active charging points, measuring and control equipment of the charging points etc. Lying If there is no further information from the vehicle or for the user's request to load it, then an unbalanced load limiting unit uses these values to limit the unbalanced load to a predetermined value.

The behavior of the vehicles, which are connected to one or more connection points of the charging cluster, is monitored by measuring and returning the charging power of the respective vehicle charging at the charging points. The maximum charging power provided to the vehicle by the charging point is calculated. The calculation is based on all vehicles at the charging points and the specified parameters of the charging points such as phase connection of the charging points, power resources of the charging cluster and returned power measurements. The temporal resolution of the power measurement is chosen to be at least as high as the time limit of the power upper limit intended by the system operator of the charging cluster.

If given boundary conditions on a phase change, for example by another vehicle being connected to the charging points for charging or if the energy storage of a vehicle is completely charged, new values are calculated as the upper limit for all active charging points of the charging cluster. If required or desired, new values can be calculated as a performance cap for all charging points, including those charging points where a change occurred on one phase. The procedure is that the unbalanced load criterion, which is explained below, is always met.

In another advantageous development, it is provided that the reduction or increase in the charging power of one or more vehicles is used to ensure compliance with a power reference difference of the connection phases with each other.

1. 1. die auf den Anschlussphasen gemessenen Leistungen sind ermittelt,
2. 2. die Leistungsbezugsdifferenzen zwischen den Anschlussphasen (Einhaltung der Schieflastgrenzen) werden eingehalten, wobei P_Li, die Summe aller von Phase i bezogenen Leistungen, und P_SO, die Schieflastobergrenze ist: $$\left|{\text{P}}_{\text{L1}}-{\text{P}}_{\text{L2}}\right|<={\text{P}}_{\text{SO}}$$
   
   $$\left|{\text{P}}_{\text{L2}}-{\text{P}}_{\text{L3}}\right|<={\text{P}}_{\text{SO}}$$
   
   $$\left|{\text{P}}_{\text{L1}}-{\text{P}}_{\text{L3}}\right|<={\text{P}}_{\text{SO}}$$
   

The unbalanced load criterion per phase is met if the following requirements are met:

1. 1. the performances measured on the connection phases are determined
2. 2. the power reference differences between the connection phases (compliance with the unbalanced load limits) are complied with, where P _Li , the sum of all services related to phase i, and P _SO , the unbalanced load limit is: $$\left|{\text{P}}_{\text{L1}}-{\text{P}}_{\text{L2}}\right|<={\text{P}}_{\text{SO}}$$
   
   $$\left|{\text{P}}_{\text{L2}}-{\text{P}}_{\text{L3}}\right|<={\text{P}}_{\text{SO}}$$
   
   $$\left|{\text{P}}_{\text{L1}}-{\text{P}}_{\text{L3}}\right|<={\text{P}}_{\text{SO}}$$
   

These unbalanced load restrictions are stored as fixed limit values or fed to a variable input as an optimization.

If an unbalanced load occurs, the performance of the non-three-phase vehicles is adjusted in accordance with the above criteria, while at the same time ensuring compliance with the power limitation of the individual grid connection phases. The connected vehicles thus compete for the limited power resources.

The load planning advantageously includes a performance profile for the respective vehicle and the charging point. The unbalanced load is limited by optimized, phase-individual planning of the loading processes in terms of the unbalanced load criterion. To create optimal load planning for each vehicle, data about the vehicle or user behavior is needed. The vehicle data include, for example: maximum charging power, storage capacity, charging characteristic, charging energy requirement and charging mode (one, two or three-phase charging). Data on user behavior include: planned departure time, desire for immediate loading or intelligent charging, desire for air conditioning at departure time, target target SOC. Also, the data of the charging cluster is needed, which includes: connected load to the power grid, number of charging points, active charging points, etc.

The power profile advantageously provides a performance curve over the planned presence of the vehicle at the charging point.

Load planning for compliance with the unbalanced load is created. A performance profile per vehicle and charging point is calculated, which describes the performance curve over the planned presence of the vehicle at the charging point. An algorithm is used to calculate the charging schedule for each vehicle. For example, this is the bin-packing algorithm with a first-fit strategy that combinatorially uses the provided power resources in as few large power blocks as possible to achieve rapid achievement of the goal of charging the energy storage of the vehicles according to the customer's request. Another algorithm is the Viterbi algorithm, which iterates through steps comparing a weighted cost function to give an economically optimized solution to the load plan.

Should a cluster of clusters encounter a mixture of vehicles with load specifications and vehicles with load planning, all available power resources will be split between load specification and load planning. The distribution of the power resources per connection phase depends on the number of vehicles involved and their entitlement to benefits. Far-reaching strategies such as dynamic performance allocation are implemented to make better use of optimization potential.

The load plan is generated based on stored data or assumptions about a required power and / or amount of each of the one or more vehicles. The charging plan for each vehicle whose energy storage is to be charged depends on the required power or the amount of charging energy. In the preliminary planning of the charging plan, it is also possible to make use of forecasts of energy production, such as photovoltaics, as well as forecasts of further consumers using the same connection as the charging cluster and having to take account of the overall utilization of the connection. Further wishes of the vehicle user, for example the departure time, parameters for the infrastructure of the individual charging points, vehicle parameters such as storage capacity and charging characteristic.

At the beginning of the charging process, a measurement of the power for one or more charging points during an initialization phase can take place. The measurement takes place via counter or power meter. The measurement can also be made at each charging point via an external measuring system, which is not part of the charging cluster. From the measured values, the number of loaded phases is determined. After the initialization phase, it is determined whether a charging process is single-phase, two-phase or three-phase.

The phase connections of the individual charging points of the charging cluster can be stored in a database. The saving of the determined charging connections has the advantage that, when the charging plan is being created during the charging process for a vehicle connected to the respective charging point, the information is immediately taken into account which connection phases are charged in a non-three-phase charging process.

According to the invention, an unbalanced load limiting unit for carrying out the method for unbalanced load limiting is specified. The unbalanced load limiting unit advantageously comprises an information processing module for storing and providing data, a detection mode for detecting a charge type (defined by used phases and power), a charge plan module for creating a charge plan, a load demand module for load control of individual phases a charging point, a load planning module for load planning of individual phases at a charging point.

The information processing module, the detection module, the loading plan module, the load request module, the load planning module can be combined in total or at least partially in one module. The load plan module also includes determining the power resources at the grid connection point. The service resources are services that can be distributed freely depending on the actual load of the load cluster.

The information processing module receives and stores any information or data necessary to simultaneously carry out the load and unbalance control method. An unambiguous assignment of the charging point and the connected vehicle is ensured via an authentication process at the charging point. The data stored in the information processing module include vehicle and user data and can be obtained, for example, from the following sources: external databases with vehicle-specific characteristics (for example, BMW Connected Drive), special applications for smart loading on mobile devices, linking to users Accounts of service providers via an authentication or a table with deposited knowledge from previous load operations at the load cluster.

The available power resources may come from different sources, such as: photovoltaic, grid, storage, combined heat and power plants. The power values for the different sources can be of different origin: fixed configuration parameters that can be set by the operator; Database values, such as time-related performance histories; Data from connected building management systems; measurements; Forecasts.

With symmetrical infeed, power resources are evenly distributed across all three phases, so that one third of the available power is available per phase for use in the load specification module and load scheduling module.

The load plan module can detect unbalanced load on the load cluster through measurements, external information, or utilization forecasts. Depending on the network situation, the modules can limit load specification and load planning unbalanced load.

According to the invention, a charging cluster is specified, which has several charging points for charging the Energy storage of one or more vehicles, wherein the charging cluster has a unbalanced load limiting unit. The charging cluster is, for example, a fleet loading device which has a plurality of charging points to which one or more vehicles, in particular electric vehicles, are connected.

• 1: schematischer Aufbau einer Schieflastbegrenzungseinheit;
• 2: Ablauf des Verfahrens zur Schieflastbegrenzung in einer Schieflastbegrenzungseinheit.

Further details of the invention can be found in the exemplary embodiments, which are described below with reference to the figures. Show it:

• 1 : schematic structure of a unbalanced load limiting unit;
• 2 : Procedure of the method for unbalanced load limiting in a unbalanced load limiting unit.

1 shows the schematic structure of a unbalanced load limiting unit SE which includes several modules. The unbalanced load limiting unit SE is part of a charging cluster (not shown) for charging an energy storage of one or more vehicles, in particular electric vehicles. The unbalanced load limiting unit SE but can also be operated outside a charging cluster and communicatively connected to the charging points.

The unbalanced load limiting unit SE has several modules. An information processing module M1 receives and stores the information or data provided by a charging cluster and the corresponding charging points or vehicles connected to them. Furthermore, the information processing module provides M1 the stored data are available to the other modules. The information processing module M1 can be connected to an external database that provides vehicle-specific characteristics. An unambiguous assignment of a charging point of the charging cluster and the vehicle connected to it is ensured via an authentication process at the charging point. The stored data, which include vehicle and user data, can for example also from special applications for intelligent loading on mobile devices, linking to user accounts of service providers via an authentication (for example, BMW Connected Drive) or a table with deposited knowledge from previous load operations include the load cluster.

With a detection module M2 For the detection of the charging mode, it is determined whether a single-phase, two-phase or multi-phase charging is present at the charging point of the charging cluster. With a loading plan module M3 a charging plan for the charging process of the energy storage of the vehicle is created, wherein the charging plan comprises a load specification or a load planning. This is the loading plan module M3 with a load specification module M4 for load control of individual phases at a charging point, and a load planning module M5 connected to the load planning of individual phases at a charging point. The loading plan module M3 also includes the determination of the power resources at the grid connection point of the charging cluster. With symmetrical feed-in, the power resources are distributed evenly across all phases. In the case of an unbalanced network load, the loading plan module can M3 recognize this and, through measurement, external information and forecasts, determine the available performance potentials of each phase.

The unbalanced load limiting unit SE also has a module M6 for a preventive weight loss avoidance by influencing the user behavior on. The charging points of a charging cluster indicate to the user, for example the driver of the vehicle, via apps, parking guidance systems or charge points that are to be used visually at the charging point. As a result, user behavior may be influenced in the sense of avoidance of heavy load, and load-regulating interventions may be wholly or partially.

2 shows the sequence of the method for unbalanced load limiting in a load unbalance control unit SE , The modules M1 to M6 are like in 2 described.

The unbalanced load limiting unit SE is via a communication channel K with one or more charging points LP connected to the load cluster.

After connecting one or more vehicles to the charging cluster, in a first step it is checked whether vehicle-specific data (for charging mode: eg single-phase / three-phase charging vehicle, maximum charging power, characteristic of the charging characteristic) in the module M1 available. This information is sent to the load plan module M3 passed. If no data is available, it is first determined by measurements in an initialization process which phases at the respective charging point are loaded by charging and with which maximum charging power is charged.

If sufficient data is available, a loading plan in the form of load planning for the vehicle is immediately made available. The load planning is done by the load planning module M5 Determines which power profile to the charging point LP passes. The details of the load planning are as stated above and will not be explained again here.

If there is insufficient data for load planning, it is determined whether single-phase charging exists at one or more charging points and it is determined which phase in single-phase charging is charged. This is from the detection module M2 carried out. A loading plan in the form of a load specification for the vehicle is provided. The load specification is from the load specification module M4 determined and to the respective charging point LP passed. The details of the load specification are as indicated above and will not be explained again here.

In summary, it should be noted that the described measures specify a unbalanced load limiting unit and a method for unbalanced load during charging of an energy store of one or more vehicles at one or more charging points of a charging cluster, by means of which an energy- and power-optimized schedule for charging processes of electric vehicles and so-called plug-in charging systems. In-hybrid vehicles can be generated at a charging cluster consisting of several charging points. The method allows a higher utilization of the available connection power due to the phased optimization and ensuring compliance with the unbalanced load criterion for charging infrastructures with multiple charging points.

It should be understood that the methods, devices and systems described herein may be used alone as well as in combination with other methods, devices and systems described in this document. Furthermore, any aspects of the methods, apparatus, and systems described herein may be combined in a variety of ways. In particular, the features of the claims can be combined in a variety of ways.

LIST OF REFERENCE NUMBERS

SE

Unbalanced load limitation unit

M1

Information processing module

M2

Detection module

M3

Charging plan module

M4

Load default module

M5

Load planning module

M6

Module preventive weight loss prevention

LP

Load point (e)

K

communication channel

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited non-patent literature

• ISO15118 [0012]

Claims (9)

A method for unbalanced load during the charging process of an energy storage device of one or more vehicles, the vehicles being connected to one or more charging points (LP) of a charging cluster, comprising: Determining a number of phases that are loaded at one or more charging points (LP) of the charging cluster, Determining a non-three-phase charging at one or more charging points (LP), Determining the respective phases which are loaded in non-three-phase charging, - Create a charging plan for each of the one or more vehicles, based on the determined number of phases and / or the loaded phases. Method according to Claim 1 wherein the determination of the non-three-phase charging comprises - releasing an initial charging power per phase at the respective charging point (LP), - comparing the predetermined charging power with the charging power assumed by the vehicle, - determining a single-phase charging, if the charging power assumed by the vehicle is below a threshold value lies, or - detecting a two-phase charging, if the charging power assumed by the vehicle is below a further threshold value, - storing the determined charging mode and the loaded phases. Method according to Claim 1 or 2 in which a maximum charging power is determined during the charging process, comprising: - releasing a maximum charging power at the respective charging point (LP), - comparing the predetermined maximum charging power with the power assumed by the vehicle, - storing the power consumed by the vehicle as the maximum charging power. Method according to one of the preceding claims, characterized in that a reduction or increase of the charging power for charging the energy storage of one or more vehicles leads to the reduction of unbalanced load, wherein the charging power of individual vehicles is reduced or increased at a connection phase. Method according to Claim 4 , characterized in that the reduction or increase of the charging power for charging the energy storage of one or more vehicles is used to ensure compliance with a power reference difference of the connection phases with each other. Method according to one of the preceding claims, wherein the load planning comprises a performance profile for the respective vehicle and charging point (LP). Method according to one of the preceding claims, wherein the power profile provides a performance curve at least on the planned presence of the vehicle at the charging point (LP). Unbalance limiting unit (SE) for carrying out the method according to one of the preceding claims, comprising an information processing module (M1) for storing and providing data, a detection module (M2) for detecting a charge type, a loading plan module (M3) for creating a loading plan, a load specification module (M4) for load specification of individual phases at a charging point (LP), a load planning module (M5) for load planning of individual phases at a charging point (LP). A charging cluster comprising one or more charging points (LP) for charging one or more vehicles, the charging cluster having a unbalanced load limiting unit (SE) in accordance with Claim 8 having.

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