Energy management system

Abstract

An energy management system comprising a photovoltaic system (1) having at least one photovoltaic array (2) adapted to generate DC power which is converted into AC power by an inverter (4) of the photovoltaic system (1), in a normal operating mode of the photovoltaic system (1), a flow of energy within the photovoltaic system (1) is controlled according to a control value, and in a normal operating mode of the photovoltaic system (1), the flow of energy within the photovoltaic system (1) is controlled according to the control value. The control value is received as a setpoint from a remote energy management scheme operated by a remote server (14) via an Internet connection (15), and if a communication failure with the remote server (14) is detected, a standby operating mode of the photovoltaic system (1) is started, in which standby operating mode the remote server (14) is connected to the remote server (14). The energy flow within the photovoltaic system (1) is controlled as a function of a local control value provided by the local energy management scheme as a setpoint.

Description

[0001] The invention relates to an energy management system suitable for managing and controlling energy flows between entities of a photovoltaic system, in particular in the event of a communication failure in a communication connection between the photovoltaic system and a remote server.

[0002] The photovoltaic system includes an inverter for converting the direct current (DC) power generated by the photovoltaic modules of the photovoltaic array into alternating current (AC) power. The generated AC power can be supplied to the power supply grid in the normal operation mode of the photovoltaic system. The local load network can also be powered by the AC power generated by the inverter of the photovoltaic system. The load network may include various consumer appliances that consume the AC power generated by the inverter. In addition, the inverter may also be connected to a local storage unit to store energy locally. Therefore, there are different energy flows between the inverter and other entities.

[0003] When the photovoltaic array receives solar radiation, it generates DC current, and energy flows from the photovoltaic array to the inverter. The equipment of the load network receives energy from the AC side of the inverter. In addition, the energy can also be stored by the inverter in a local storage unit.

[0004] US2018 / 0351401 A1 describes an apparatus for a system power device used in an interconnected power system. The interconnected power system includes multiple system power devices. The apparatus includes a processor and a communication interface. The communication interface connects a mobile computing system of a user who is very close to the system power device.

[0005] The graphical user interface of the mobile computing system allows operation and reconfiguration options of the power system, including installation, maintenance and monitoring schedules in the power system when the user is in close proximity to the system power equipment.

[0006] EP 2941809 B1 describes an energy control system configured to control energy transmission to an electrical load. The energy control system comprises a renewable energy source, a storage energy source, a memory configured to store program instructions, and an energy system controller. The energy controller of the energy control system has a predictor module, a scheduling planner module, and a scheduling module, and the scheduling module controls energy transmission between the storage energy source to the electrical load and to the storage device.

[0007] During normal operation of a photovoltaic system, the system is connected to the power grid or the power supply network. There can be an energy flow from the photovoltaic system to the power grid and vice versa. However, in emergency situations, the photovoltaic system is disconnected from the power grid. This situation requires effective energy management.

[0008] In many use cases, the set point for energy management of energy flows within a photovoltaic system is provided by a remote server of the cloud. The set point is calculated by a controller of the server within the cloud according to a remote energy management scheme. The reason for providing a remote set point is that the computing power of the controller within the photovoltaic system is more limited than the computing power of the controller of the server within the cloud in many use cases. In addition, the remote energy management scheme allows central adjustment and maintenance of the involved calculation algorithms. However, the provision of the remote set point relies on data communication between the server of the cloud and the controller of the inverter within the photovoltaic system or the controller of the local energy management system implemented at the site of the photovoltaic system. Therefore, the energy management system of the photovoltaic system operating according to the remote set point is neither robust nor resilient to interruptions or communication problems of the Internet connection between the photovoltaic system and the remote server. Conventional energy management systems for photovoltaic systems operating according to remote set points are also neither robust nor resilient to the unavailability of the remote server, especially during maintenance of the remote server.

[0009] It is therefore an object of the present invention to provide an energy management system which is robust to communication defects of the communication connection between a controller of a photovoltaic system and a remote server.

[0010] This object is achieved by an energy management system and a corresponding method having the features of the independent claims. Further advantageous embodiments are subject matter of the dependent claims.

[0011] According to a first aspect, the present invention provides an energy management system for a photovoltaic system, the photovoltaic system having at least one photovoltaic array, the at least one photovoltaic array being adapted to generate DC power, the DC power being converted into AC power by an inverter of the photovoltaic system;

[0012] wherein, in a normal operating mode of the photovoltaic system, energy flow within the photovoltaic system is controlled according to a control value received as a set point from a remote energy management solution run by a remote server via an Internet connection;

[0013] wherein, during the normal operating mode, the remote energy management scheme executed by the remote server periodically or continuously transmits set points via the Internet connection; and

[0014] Wherein, if the communication with the remote server fails, a backup operation mode of the photovoltaic system is initiated, in which the energy flow within the photovoltaic system is controlled according to a local control value provided as a set point by a local energy management solution.

[0015] In a possible embodiment of the energy management system according to the first aspect of the present invention, after the communication failure with the remote server occurs at time point A, the energy management system uses the local control value provided by the local energy management scheme in the backup operation mode at time point B after time period t1.

[0016] In a possible embodiment of the energy management system according to aspects of the invention, the switchover from the remote control value to the local control value is started after the time period t1, and during the time period t2, the local control value is smoothly reached and used as a set point to control the energy flow within the photovoltaic system.

[0017] In a possible embodiment of the energy management system according to the invention, in the backup operating mode the local energy management scheme is executed to optimize the self-consumption of electricity generated by the photovoltaic array of the photovoltaic system by power consumers of a local load network of the photovoltaic system.

[0018] The local energy management scheme may be executed in the backup operating mode of the photovoltaic system by a controller of the inverter of the photovoltaic system or by a controller of the energy management unit of the photovoltaic system.

[0019] In a possible embodiment of the energy management system according to the invention, the photovoltaic system comprises an inverter adapted to convert DC power generated by photovoltaic modules of the photovoltaic array into AC power supplied to the power supply grid via the measuring device in normal operation mode of the photovoltaic system.

[0020] In another possible embodiment of the energy management system according to the invention, the inverter is connected to at least one storage unit of the photovoltaic system for storing electrical power.

[0021] In another possible embodiment of the energy management system according to the present invention, the energy flow manager is suitable for monitoring and controlling the energy flow between the inverter and other entities of the photovoltaic system connected to the inverter (in particular, power consumers of the load network of the photovoltaic system), including the energy flow from the photovoltaic array to the DC side of the inverter, the energy flow from the inverter to the at least one storage unit of the photovoltaic system, and the energy flow between the photovoltaic system and the power supply grid.

[0022] In another possible embodiment of the energy management system according to the invention, the energy flow manager is executed on a processor of a controller, which is suitable for calculating instantaneous energy flows, in particular instantaneous energy flows, based on data provided by different entities of the photovoltaic system including measuring devices and / or power-consuming loads of the load network.

[0023] The controller may be a controller of the inverter of the photovoltaic system or a controller of a dedicated energy management unit of the energy management system for controlling the energy flow of the photovoltaic system.

[0024] In another possible embodiment of the energy management system according to the present invention, if a power supply grid fault has been detected based on the data provided by the measuring device, as long as the photovoltaic system is operated in an emergency operating mode, the emergency switch of the photovoltaic system is automatically disconnected by the controller of the inverter or by the controller of the energy management unit to automatically disconnect the power supply grid from the photovoltaic system, thereby causing an interruption of the energy flow between the inverter and the power supply grid.

[0025] In another possible embodiment of the energy management system according to the present invention, if an interruption of the Internet connection caused by the power supply grid is detected, the energy management system is suitable for notifying a user through a user interface of an emergency operation mode of the photovoltaic system triggered by the power supply grid failure and / or the interruption of the Internet connection caused by the power supply grid failure, and is suitable for triggering the backup operation mode.

[0026] In another possible embodiment of the energy management system according to the present invention, the user interface is integrated in a user device that communicates with the energy management system.

[0027] In another possible embodiment of the energy management system according to the present invention, the user interface is integrated into the energy management system of the photovoltaic system.

[0028] In another possible embodiment of the energy management system according to the invention, the user device is integrated into a visual display unit, in particular an LED display board.

[0029] In another possible embodiment of the energy management system according to the present invention, predictions and recommendations for the emergency operation mode of the photovoltaic system are calculated based on collected data provided by the entities of the photovoltaic system during the emergency operation mode and based on data calculated during the normal operation mode of the photovoltaic system before a fault in the power supply grid is detected and an emergency switch is opened by the controller of the inverter or the controller of the energy management unit of the energy management system to interrupt the energy flow between the photovoltaic system and the power supply grid.

[0030] In a possible embodiment, the collected data are stored in a local data memory of the energy management system.

[0031] In a possible embodiment of the energy management system according to the present invention, the collected data includes solar power generation capacity data, solar radiation data, solar power generation capacity forecast data, load usage and power consumption forecast data, load priority data, initial user input data, storage unit energy level data, user input data, in particular responses to predictions and recommendations, and measurement device data generated by the measurement device.

[0032] In another possible embodiment of the energy management system according to the invention, the user device communicating with the energy management system comprises a mobile user device, such as a smartphone, connected to the energy management system of the photovoltaic system via a wireless link.

[0033] According to another aspect, the invention provides a method for performing energy management of a photovoltaic system, the photovoltaic system having at least one photovoltaic array, the at least one photovoltaic array being adapted to generate DC power, the DC power being converted into AC power by an inverter of the photovoltaic system, wherein the method comprises the following steps:

[0034] - in a normal operating mode of the photovoltaic system, performing control of the energy flow within the photovoltaic system according to control values ​​received as set points via an Internet connection and calculated by a remote energy management scheme run by a remote server,

[0035] wherein the set point is transmitted periodically or continuously via the Internet connection by the remote energy management scheme executed by the remote server during the normal operating mode;

[0036] - if a communication failure with the remote server is detected, a backup operation mode of the photovoltaic system is initiated, wherein in the backup operation mode of the photovoltaic system the energy flow within the photovoltaic system is controlled according to local control values ​​provided as set points by a local energy management solution.

[0037] In the following, possible embodiments of different aspects of the present invention will be described in more detail with reference to the accompanying drawings.

[0038] Figure 1 shows a block diagram for illustrating a possible exemplary embodiment of an energy management system;

[0039] Figure 2 A flow chart showing a possible exemplary embodiment of a method for managing energy flow within a photovoltaic system;

[0040] Figure 3 A possible exemplary implementation of a graphical user interface of a user device is shown;

[0041] Figure 4The operation of backup energy flow management within an energy management backup system according to the present invention is described;

[0042] Figure 5 A flow chart is shown for illustrating a possible exemplary embodiment of the method according to the invention for carrying out energy flow management within a photovoltaic system.

[0043] Figure 1 A possible exemplary embodiment of a photovoltaic system 1 is schematically shown, the photovoltaic system 1 comprising an energy management system 8 for managing the energy flow of the photovoltaic system 1. The photovoltaic system 1 comprises at least one photovoltaic array 2, the at least one photovoltaic array 2 comprising photovoltaic modules 3 adapted to generate direct current DC power supplied to the DC side of an inverter 4. The inverter 4 is adapted to convert the received DC power generated by the photovoltaic modules 3 of the photovoltaic array 2 into alternating current AC power. The AC power generated by the inverter 4 can be supplied to a power supply grid 16 connected to the photovoltaic system 1 via an AC line and a measuring device 5.

[0044] In the embodiment shown, the photovoltaic system 1 further comprises an emergency switch 6 suitable for interrupting the connection between the photovoltaic system 1 and the power supply grid 16 in an emergency, in particular if the measuring device 5 detects a power supply grid failure of the power supply grid 16 .

[0045] On the AC side of the inverter 4, a load network 7 may be connected to the AC line, such as Figure 1 As shown. The load network 7 includes a plurality of power consuming devices. For example, the power consuming device is a washing machine in a private household. Another example of a power consuming device of the load network 7 is a machine in a manufacturing facility. The load network 7 may include several loads of different types that consume the AC power generated by the inverter 4.

[0046] like Figure 1 The photovoltaic system 1 shown further comprises an energy management unit 8, which can also be connected to the inverter 4 of the photovoltaic system 1. The energy management unit 8 can be connected to a local data memory 9 suitable for storing data. The memory 9 can also be integrated in the energy management unit 8. The energy management unit 8 of the photovoltaic system 1 forms part of an energy management system for managing the energy flow of the photovoltaic system 1.

[0047] Furthermore, a storage unit 10 may be provided to store electrical energy locally in the photovoltaic system 1. The storage unit 10 may comprise a battery suitable for storing DC power. Figure 1 In the exemplary embodiment shown, the energy management system includes an access point 11 having a Figure 1 In an alternative embodiment, the energy management system can also be connected to a fixed user terminal via a data interface. The user equipment 12 includes Figure 3 The user interface 13 shown is used to display information to the user U (such as changes in operating modes).

[0048] like Figure 1 The energy management system of the photovoltaic system 1 shown in the figure uses the user interface 13 to notify the user U about the detected communication failure, in particular about the communication interruption or server failure of the remote server 14, the unavailability of the remote server 14, and to notify the user U about the change of the operation mode. In this case, the activation of the backup operation mode can be automatically performed. Generally, the photovoltaic system 1 can be operated in the normal operation mode or the backup operation mode.

[0049] In one possible embodiment, the energy management system may be implemented on a processor (which may be located in the inverter 4 or in an external device) and may be used to calculate the instantaneous energy flow from data provided by different entities of the photovoltaic system 1 including the measuring device 5 and / or the loads of the load network 7. For example, the energy management system may be implemented on a controller of the energy management unit 8 to calculate the instantaneous energy flow from the measured data.

[0050] In an alternative embodiment, the functionality of the energy management system may be at least partially provided by a remote server 14 which may be connected to the photovoltaic system 1 , in particular to an interface of the energy management unit 8 of the energy management system, via the Internet or another data network.

[0051] A failure of the power supply grid 16 may also result in an interruption of the Internet 15 , which results in the remote server 14 being disconnected from the photovoltaic system 1 . A failure of the power supply grid 16 may result in a communication failure of the Internet connection 15 .

[0052] In a preferred embodiment, if a communication failure is detected (e.g., if the Internet connection 15 is interrupted or unavailable and / or the remote server 14 is detected to be unavailable), then Figure 1 The energy management system implemented on the energy management unit 8 of the photovoltaic system 1 shown changes the mode from the normal operating mode to the backup operating mode as shown in Figures 5, 6. The backup operating mode can also be activated in parallel with the emergency operating mode if the Internet connection 15 and the grid 16 are not available.

[0053] exist Figure 1 In the illustrated embodiment, the user interface 13 is integrated in a user device 12 that communicates with the energy management system 8 via a wireless connection such as wireless fidelity WiFi. In alternative embodiments, the user interface 13 may also be integrated in the energy management unit 8 of the energy management system itself. In addition, the user interface 13 may also be connected to other devices that communicate with the energy management system, such as an LED display board that may be hung on the wall of the facility.

[0054] In a preferred embodiment, the user device 12 comprises an energy management application APP, which is suitable for informing the user U about the current operation mode (normal operation mode and backup operation mode) of the photovoltaic system 1 via the user interface 13 of the user device 12. The energy management application APP can also inform the user U about the interruption of the Internet connection 15 and / or the unavailability of the remote server 14, and can inform the user U that the energy management system uses the local control value as the set point instead of the remote control value from the remote server 14.

[0055] Figure 2 A possible exemplary embodiment of the method according to the invention for managing the energy flow in a photovoltaic system 1 with a backup operating mode is shown. Figure 2 In the embodiment shown, the method comprises two main steps.

[0056] In a first step S1, the user U is informed of the change in the operating mode of the photovoltaic system 1 triggered by the detected communication failure with the remote server 14 through the user interface 13. Thus, the user U knows that the photovoltaic system 1 is now operating in a backup operating mode using local control values ​​and no longer in a normal operating mode using remote control values.

[0057] In a further step S2 , the energy management system implemented on energy management unit 8 is operated in a backup operating mode using local control values.

[0058] The Internet connection 15 may also be interrupted or damaged due to other reasons than a power grid failure of the power grid 16. For example, a server failure of the remote server 14 or maintenance of the remote server 14 leads to an interruption of data retrieval from the remote server 14. Therefore, in a preferred embodiment, during the normal operation mode, the availability of the Internet connection 15 and the availability of the remote server 14 are regularly checked to ensure that the controller of the energy management unit 8 of the energy management system of the photovoltaic system 1 receives the set point from the remote server 14 to perform normal energy flow management within the photovoltaic system 1. In this case, the energy management system receives a remote control value, which is used as a set point for energy flow control. Therefore, the energy flow is managed according to the remote energy management scheme. The remote control value can be calculated in real time.

[0059] If the energy management system, in particular the controller of the inverter 4 of the photovoltaic system 1, detects an interruption or significant impairment of the network connection 15 or unavailability of the remote server 14, or another assigned detection unit of the energy management system of the photovoltaic system 1 detects an interruption or significant impairment of the network connection or unavailability of the remote server, the backup operating mode of the photovoltaic system 1 is automatically started by the corresponding controller, and the other assigned detection unit can monitor the data transmission rate or packet transmission rate via the monitored network connection 15. In the backup operating mode, the energy flow within the photovoltaic system 1 is controlled by the energy management system according to the local control value provided as the set point. This is also Figure 5 The local control values ​​can be stored in the data memory 9 and can be loaded as set points from the energy management unit 8 in the backup operating mode. Thus, the energy flow is managed in the backup operating mode according to the local energy management scheme. The local control values ​​can be calculated in real time or can be derived from stored default values.

[0060] In the event of a communication failure being detected, switching is performed between the local energy management scheme and the remote energy management scheme. During normal operating mode, the remote energy management scheme is active. Both schemes can also work together. Here, the local energy management scheme receives set points from the remote energy management scheme and then manages the local energy flow. In the setup mode of the application APP, the user U can perform configuration of the power consuming devices of the load network 7 and other entities of the corresponding photovoltaic system 1. The user U can also enter additional parameters, such as a time period or time window for forecast data. For example, the user U can indicate whether to store forecast data for the next 24 hours or store for a longer time period. This is a possibility to take into account the possibility of losing Internet connection.

[0061] During setup, the energy management system may automatically start communicating with all relevant entities of the photovoltaic system 1 via the local communication bus to receive information about entities and loads available in the local photovoltaic system 1. Thus, the energy management system may collect information about different power consumers and other entities connected to the inverter 4 of the photovoltaic system 1 to generate a list displayed to the user U via the user interface 13. The user U may perform individual configurations of the displayed available loads and entities. For example, the user U may define the priority of the loads of the load network 7 in the standby operating mode.

[0062] Based on the collected information, forecast data can be calculated by the energy management system. For example, the expected daily photovoltaic energy generation of the photovoltaic array for future days can be calculated based on the collected information. In addition, the expected daily load usage and total load usage of each load in the load network 7 can be calculated based on the collected information and user input.

[0063] The energy management system dynamically dispatches power to each of the available electrical loads based on at least one of a user preference, and / or collected data stored in a data store.

[0064] The energy management system according to the present invention provides backup energy flow management in a backup operating mode in the event that the Internet connection 15 between the system's remote server 14 and the photovoltaic system 1 is interrupted or significantly damaged, or in the event of a server failure of the remote server 14 or during maintenance of the remote server 14.

[0065] The energy management system operates in a normal operation mode within the photovoltaic system 1 and is performed by controlling the energy flow within the photovoltaic system 1 according to control values ​​received as external set points from a remote energy management scheme provided from a remote server 14 via an Internet connection 15. If a communication failure is detected, in particular if an interruption of the Internet connection 15 between the remote server 14 and the photovoltaic system 1 is detected or a server failure of the remote server 14 is observed, a backup operation mode of the photovoltaic system 1 is automatically initiated. The interruption of the Internet connection 15 may be detected by a controller of an inverter 4 of the photovoltaic system 1 or an associated interruption detection unit of the photovoltaic system 1. In response to the detected interruption of the Internet connection or the observed server failure, the energy flow within the photovoltaic system 1 is no longer controlled according to the remote control values ​​received as set points of the remote energy management scheme, but is instead controlled according to the remote control values ​​received as set points of the remote energy management scheme. Figure 4 In the event of a communication interruption and / or in the event of a server failure of the remote server 14 being observed, the remote setpoint received from the remote server 14 can no longer be transmitted to the controller of the inverter 4 or the controller of the energy management unit 8.

[0066] like Figure 4 As shown in the diagram, at time point A, a communication failure occurs (such as an interruption of the communication connection between the remote server 14 and the photovoltaic inverter 4 or a server failure of the remote server 14). During the time period t1, the communication failure is detected, for example, based on the data transmission rate DTR and / or the packet transmission rate PTR of the data packets via the Internet connection 15 and / or the missing set points sent periodically (timeout of the last set point reception). At the activation time point B, the controller of the inverter 4 starts the transition to the local energy management scheme after the time period t1. The time period t1 can, for example, be predefined, or depend on the rate level (DTR, PTR) or be triggered by an event. The time period t1 is the time between the occurrence of the communication failure at time point A and the start of the transition from using remote control values ​​to using local control values ​​at time point B. According to the local energy management scheme, the local control values ​​are used after time point B. As Figure 5As can be seen from the diagram in FIG. 1 , the function smoothly approaches the local control value reached at point C during the time period t2 without abrupt changes to avoid undesirable oscillations. The duration of the time period t2 depends on the difference between the remote control value and the local control value. In a preferred embodiment, the energy management system is adapted to activate the local energy management scheme within a time period t1 after an interruption in the Internet connection 15 or after a server failure (timeout). The energy management system then activates the local energy management scheme according to the following formula: Figure 4 The local control value shown in Figure 1 forms the set point for executing the backup operating mode.

[0067] In a preferred embodiment, the local control values ​​are applied by the energy management system of the photovoltaic system 1 to optimize the self-consumption of the electricity generated by the photovoltaic array 2 of the photovoltaic system 1 by the power consumers of the local load network 7 of the photovoltaic system 1. In a normal operating mode, when the Internet connection 15 is not interrupted and the remote server 14 is available, the set points are transmitted by a remote energy management solution running on the remote server 14. These set points can be transmitted periodically or continuously by the remote server 14 to the energy management system of the photovoltaic system 1 via the Internet connection 15.

[0068] Figure 5 A flow chart illustrating possible exemplary embodiments of different modes of operation according to the present invention is shown. During normal operation, in step S A In step S, normal energy management is performed by controlling the energy flow within the photovoltaic system 1 by remote control values ​​received as set points according to a remote energy management scheme running on a remote server 14 via an Internet connection 15. B In the embodiment of the present invention, a communication failure with the remote server 14 is detected by the energy management system. The communication failure may include an interruption of the Internet connection 15 or the unavailability of the remote server 14. If a communication failure is detected, the energy management system automatically switches from the normal operation mode to the backup operation mode. In the backup operation mode, the backup energy management system automatically switches from the normal operation mode to the backup operation mode. Figure 5 Step S shown C The backup operation mode may be automatically started and executed in step S by a controller of the inverter 4 and / or by a controller of an energy management unit 8 forming part of an energy management system of the photovoltaic system 1 by using a local control value provided as a local set point by a local energy management scheme. C The local energy management strategy used in the photovoltaic system 1 is, for example, concerned with optimizing the energy self-consumption within the photovoltaic system 1 . The local control values ​​can be read from a local data memory 9 of the photovoltaic system 1 .

[0069] The external setpoints received by the controller of the inverter 4 or by the controller of the energy management system 8 from the remote server 14 may, for example, include different types of information, such as tariff data, weather data, consumption history data and forecast data. The use of local setpoints and local measurement data also allows optimization of energy flows, however without optimization based on predictions or forecasts. Thus, the use of external or remote setpoints allows optimization of energy flows based on prediction or forecast data also during normal operation of the photovoltaic system 1.

[0070] In a possible embodiment, the availability of the Internet connection 15 between the remote server 14 and the photovoltaic system 1 and the availability of the remote server 14 are checked at regular time intervals and / or event-driven by a controller or by a detection unit of the photovoltaic system 1 .

[0071] In a possible embodiment, an interruption of the Internet connection 15 is determined if the monitored data transmission rate DTR of the Internet connection 15 drops below a predetermined data rate threshold.

[0072] In a possible embodiment, an interruption of the Internet connection 15 or unavailability of the remote server 14 or interruption of the remote energy management service is determined if remote setpoints or data packets from the remote server 14 are no longer transmitted to the energy management system. One way to detect such an interruption includes a local timeout.

[0073] In a possible embodiment, if the ping value from the remote server 14 is no longer transmitted to the energy management system, an interruption of the Internet connection 15 or unavailability of the remote server 14 or an interruption of the remote energy management service is determined. These ping values ​​can be used as a periodic live signal to detect an interruption of the connection or a cloud server failure.

[0074] If the Internet connection 15 is reestablished, the method returns to normal energy flow management in normal operation mode in step SA. In normal energy management, the energy flow within the photovoltaic system 1 is controlled according to control values ​​received as set points via the established Internet connection 15 according to a remote energy management scheme run by the remote server 14.

[0075] In a possible implementation, the graphical user interface 13 may also indicate a damage to the Internet connection 15, such as a reduction in the available data transmission rate. If the data transmission rate of the Internet connection 15 is below a predetermined threshold, the transmission of the remote setpoints may take too long a time period to reliably use them as control values ​​for the energy management system within the photovoltaic system 1. In this case, an automatic switch to the standby operating mode SC is initiated by the local controller of the photovoltaic system 1. The available data transmission rate of the Internet connection 15 can be displayed to the user U by means of the graphical user interface 13. In a possible further implementation, the user U may also be informed of the cause of the Internet communication failure. For example, the user U may be informed that the Internet connection interruption is caused by a failure of the local power supply through the power supply grid 16. The user U may also be informed that the Internet connection interruption or other reasons for the unavailability of the server have triggered the switch to the standby operating mode of the photovoltaic system 1. During the normal operating mode, the remote control value is transmitted via the communication interface to be executed locally. However, if these external remote control values ​​can no longer be transmitted due to a communication failure, the controller of the local inverter 4 of the photovoltaic system 1 or the controller of the energy management unit 8 can activate the backup operating mode after a period of time t1 and can use the Figure 4 Describes the predefined and stored local control values.

[0076] For example, according to Figure 4 , since the price of electricity from the power supply grid 16 is very low and no PV power is available, the power of the inverter 4 can be set by an external set point (remote control value) so that electricity (i.e., the output power of the inverter 4) flows from the power supply grid 16 into the electric storage unit 10 and flows to the load of the load network 7 of the photovoltaic system 1. Therefore, the output power of the inverter 4 is negative. As a local control value, the use of the PV power of the inverter 4 is defined to cover, for example, the load of the load network 7 of the corresponding photovoltaic system 1, and to feed electricity into the power supply grid 16 if necessary. In this case, if the controller of the inverter 4 or another detection unit detects an interruption of the communication connection (i.e., the Internet connection 15) or the server of the remote server 14 is unavailable, the controller can change after the time period t1 according to an exponential function with a negative exponent in the time period t2 from receiving power (remote control value) to supplying power (local control value). This local control value is only executed when the controller of the energy management system has not received the external remote control value again from the remote server 14 via the re-established Internet connection 15, or before the controller of the energy management system receives the external remote control value that has become available again from the remote server 14 (for example after maintenance of the remote server 14 has been completed).

[0077] For the switch from the standby operating mode SC to the normal operating mode SA, the process is in principle the same. In particular, during the control time t2, there is a continuous switch from the local value to the remote value and vice versa. The control time t2 is related to the control of the energy flow.

Claims

1. An energy management system, comprising a photovoltaic system (1) having at least one photovoltaic array (2), the photovoltaic array (2) being adapted to generate DC power, the DC power being converted into AC power by an inverter (4) of the photovoltaic system (1); in, In a normal operating mode of the photovoltaic system (1), the energy flow within the photovoltaic system (1) is controlled according to control values ​​received as set points from a remote energy management solution run by a remote server (14) via an Internet connection (15); wherein during the normal operating mode, the remote energy management scheme executed by the remote server (14) periodically or continuously transmits set points via the Internet connection (15); and If a communication failure with the remote server (14) is detected, a backup operation mode of the photovoltaic system (1) is initiated, in which the energy flow within the photovoltaic system (1) is controlled according to a local control value provided as a set point by a local energy management scheme.

2. The energy management system according to claim 1, wherein: After the communication failure with the remote server (14) occurs at time point A, the energy management system uses the local control values ​​provided by the local energy management scheme in the backup operating mode at time point B after a time period t1.

3. The energy management system according to claim 1 or 2, wherein: After the time period t1, the switchover from the remote control value to the local control value is started, and during a time period t2, the local control value is smoothly reached and used as a set point to control the energy flow within the photovoltaic system (1).

4. The energy management system according to any one of claims 1 to 3, wherein: In the backup operating mode, the local energy management scheme is executed to optimize the self-consumption of electricity generated by the photovoltaic array (2) of the photovoltaic system (1) by power consumers of a local load network (7) of the photovoltaic system (1).

5. The energy management system according to any one of claims 1 to 4, wherein: The Internet connection (15) between the remote server (14) and the photovoltaic system (1) and / or the unavailability of the remote server (14) is checked at regular time intervals by a controller or a detection unit of the photovoltaic system (1).

6. The energy management system according to claim 5, wherein: If the data transmission rate DTR or the packet transmission rate PTR via the Internet connection (15) falls below a predetermined threshold, a communication failure with the remote server (14) is detected by a controller or a detection unit of the photovoltaic system (1).

7. The energy management system according to claim 5 or 6, wherein: If remote setpoints or data packets from the remote server (14) are no longer transmitted to the photovoltaic system (14), a communication failure with the remote server (14) is detected.

8. The energy management system according to any one of claims 5 to 7, wherein: If ping values ​​from the remote server (14) are no longer transmitted to the photovoltaic system (1), a communication failure with the remote server (14) is detected.

9. The energy management backup system according to any one of claims 1 to 8, wherein: A user is notified of a communication failure with the remote server (14) via a user interface (13).

10. A method for performing energy management of a photovoltaic system (1), the photovoltaic system (1) having at least one photovoltaic array (2), the at least one photovoltaic array (2) being adapted to generate DC power, the DC power being converted into AC power by an inverter (4) of the photovoltaic system (1), wherein: The method comprises the following steps: - performing (SA) control of the energy flow within said photovoltaic system (1) in a normal operating mode according to control values ​​received as set points via an Internet connection (15) and calculated by a remote energy management solution run by a remote server (14), wherein the set point is transmitted periodically or continuously via the Internet connection (15) by the remote energy management scheme executed by the remote server (14) during the normal operating mode; - If a communication failure with the remote server (14) is detected (SB), a backup operating mode (SC) of the photovoltaic system (1) is initiated, wherein in the backup operating mode the energy flow within the photovoltaic system (1) is controlled according to local control values ​​provided as set points by a local energy management solution.

11. Method for performing energy management of a photovoltaic system (1) according to claim 10, wherein the local control value is read from a local data memory (9) of the photovoltaic system (1) or calculated in real time.

12. The method according to claim 10 or 11, wherein: The Internet connection (15) between the remote server (14) and the photovoltaic system (1) and / or the availability of the remote server (14) is checked at regular time intervals by a controller or a detection unit of the photovoltaic system (1).

13. The method according to any one of claims 10 to 12, wherein: If the data transmission rate DTR or the packet transmission rate PTR via the Internet connection (15) falls below a predetermined threshold, a communication failure with the remote server (14) is detected.

14. The method according to any one of claims 10 to 13, wherein: A communication failure with the remote server (14) is detected if a remote set point or data packet from the remote server (14) is no longer transmitted to the photovoltaic system (14); and / or, Therein, if a ping value from the remote server (14) is no longer transmitted to the photovoltaic system (1), a communication failure with the remote server (14) is detected.

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