Local area network power management device

Abstract

The invention relates to a power management device (1) incorporating a network input (3); a local area network power interface (5); an islanding switch (7); an uninterruptible power supply (9); a central controller (10); at least one home battery (11); at least one bidirectional electric vehicle charging station (12) (13) connected to the home battery (11) such that the home battery (11) can be used to charge the electric vehicle (13) and, when an electric vehicle (13) is plugged in with sufficient charge, a battery from the electric vehicle can be used to charge the home battery (11); and a grid-forming inverter (14) such that the power management device can operate in an islanding mode in which the home battery (11) and / or the electric vehicle battery (13) supply power to the interface (5). Figure for the abstract: Fig. 1.

Description

Title of the invention: Local area network power management device technical field

[0001] The present invention relates to the management of the power supply of a local electrical network, in particular for a dwelling or an industrial installation.

[0002] The invention finds a particularly advantageous application for optimizing the use of a home battery and an electric vehicle battery, both when the local network is supplied by the distribution network (mode “off-grid”), and when the local network is supplied by one or both of the aforementioned batteries (mode “on-grid”). Previous technique

[0003] With rising energy costs and growing concerns about the environmental impact of traditional energy sources, it is becoming imperative to develop efficient and sustainable solutions for managing the power supply of local consumer electricity networks.

[0004] These solutions are advantageously compatible with domestic energy production methods, such as photovoltaic panels, and allow for the best use of available storage capacities such as domestic batteries, and batteries of electric vehicles connected to the local network via a charging station.

[0005] These solutions sometimes include an "off-grid" or islanding mode, allowing the local network to be supplied without using the external distribution network.

[0006] US patent 11011913 proposes such a system, enabling an islanding mode in which the local grid is powered by an electric vehicle battery and / or a home battery. This system has the disadvantage of being complex, requiring a large number of components, and causing a temporary interruption of the local grid power supply when the control system is triggered.

[0007] The technical problem of the invention is therefore to propose a power management system for a local network which allows the energy stored in a home battery and in an electric vehicle to be used in an optimized and economically efficient manner, in "on-grid" and "off-grid" mode, the system being arranged in an original way in order to reduce the number of components required and to allow the uninterrupted supply of the local network. Description of the invention

[0008] The present invention aims to address this technical problem by proposing a local network power management device integrating: - a network input; - a local network power interface; - an islanding switch, one terminal of which is connected to the network input; - a voltage sensor, positioned between the low-voltage network input and the islanding switch; - an uninterruptible power supply disposed between a second terminal of said islanding switch and the power interface of a local network, said uninterruptible power supply being configured to maintain the power supply to the local network without interruption for a first predetermined period; - a central controller, configured to receive measurements from said voltage sensor and open the islanding switch when the measured voltage is below a certain threshold for a second predetermined duration; - at least one domestic battery capable of supplying the local network for a third predetermined period, longer than the first predetermined period; - at least one bidirectional electric vehicle charging station connected to the home battery so that the home battery can be used to charge the electric vehicle and, when an electric vehicle is plugged in with sufficient charge, a battery from the electric vehicle can be used to charge the home battery; - a grid forming inverter, comprising an AC input connected to the second terminal of said islanding switch, and a DC output connected to the home battery and the bidirectional charging terminal, so that the power management device can operate in an islanding mode in which the home battery and / or the electric vehicle battery supply the power interface.

[0009] The invention thus makes it possible to optimize the use of batteries since, in normal operating mode, the domestic battery can be used in addition to the power supplied on the network input to power the charging station and allow a fast charging of the electric vehicle.

[0010] Furthermore, in islanding mode, the home battery can be supplemented by the electric vehicle battery to ensure the longest possible local grid supply. In this islanding mode, the electric vehicle can be disconnected, and only the home battery then supplies the local grid. Moreover, by regularly charging the electric vehicle at fast charging stations, it is even possible to recharge the home battery and supply the local grid via the electric vehicle battery, thus ensuring a local grid supply. theoretically for an unlimited period, provided that the battery capacity of the electric vehicle is sufficient with regard to the consumption of the local network.

[0011] Between normal operating mode and islanding mode, the uninterruptible power supply provides power to the local network. This uninterruptible power supply is preferably also used to power certain components of the power management device of the invention, in particular the central controller, the auxiliary components of the home battery and the inverter, and the islanding switch.

[0012] The quality of the electrical signal on an islanded network, particularly its harmonic distortion, is generally lower than on a non-islanded network and, depending on the sensitivity of the electrical components on the islanded network, may require the use of costly filtering systems. An uninterruptible power supply (UPS), as positioned downstream of the grid forming inverter, makes it possible to filter the electrical signal entering the local network and guarantee its quality even in the event of islanding.

[0013] In addition to normal and islanding modes, it is also possible to use batteries to implement a balancing mode. In this embodiment, the central controller is connected to a device that measures the characteristics of the electrical signal from the grid, in particular its voltage and frequency. By reading these characteristics, the central controller can command the local grid power management device in a balancing mode, in which the islanding switch is closed and the home battery and / or the electric vehicle battery are used to inject or draw power from the grid input. The central controller can also command the power management device in balancing mode based on data obtained via a communication network to which it is connected.

[0014] Another operating mode uses the home and / or electric vehicle batteries to optimize the local grid power supply when the islanding switch is closed. In this embodiment, the central controller is typically connected to a communication network and / or the installation meter to command the local grid power management device to charge and discharge the batteries at the appropriate time. For example, the grid power management device can be commanded to: - to charge the batteries when electricity drawn from the grid is cheap, without exceeding the maximum permitted subscribed power on the local grid; and - to use the batteries to power the local grid when electricity drawn from the grid is expensive.

[0015] Thanks to these provisions, the device according to the invention allows optimal use of electrical energy resources from the grid and stored in the home battery and in the electric vehicle battery, in "on-grid" mode as well as in "off-grid" mode.

[0016] The network connected to the network input may be a low-voltage network, but the network input may incorporate protection and transformation devices to connect a high-voltage or medium-voltage network, depending on the local network to be protected. In the case of a low-voltage network, the local network is preferably a domestic network. In the case of a high-voltage network, the local network is preferably an industrial network.

[0017] At least one of the loads enabling the local network to be re-energized in the event of a power outage, including the central controller, a backup circuit of the network formation inverter, the auxiliaries, the central controller, may be connected downstream of the uninterruptible power supply, so as not to require an uninterruptible power supply for each component.

[0018] The central controller can be configured to close a grounding switch to ground the main power supply of said local network when the islanding switch is open, thereby automatically grounding the network and ensuring its safety. In a particular embodiment of the invention, this grounding switch can be directly integrated into the device.

[0019] The first predetermined duration may be less than 5 min, which is a sufficient duration to start the "off-grid" mode, and more specifically the supply of the local network via the home battery and / or the electric vehicle battery.

[0020] The third predetermined duration can be between 24 and 48 hours, which is generally sufficient to restore the low voltage network following a power outage.

[0021] The power of the domestic battery can be between 10 and 20 kW, which is a power output particularly suited to a typical domestic network. When the local network is an industrial network, the power of the domestic battery can be higher, for example between 20 and 250 kW.

[0022] The home battery may include a battery controller connected to the uninterruptible power supply, the uninterruptible power supply being able to be configured to maintain the power supply to the battery controller for a certain predetermined period, thus avoiding the use of an additional uninterruptible power supply.

[0023] Said management device may include an interface to a photovoltaic installation, said interface being connected to the grid-forming inverter, which allows for optimal use of the energy produced by the photovoltaic installation in combination with the energy stored in the home battery, in the electric vehicle battery, and with energy from the low voltage network.

[0024] Said management device may include a DC-DC converter, connected between the grid forming inverter and said bidirectional charging station, which allows the electric vehicle to be charged more quickly. Brief description of the drawings

[0025] The present invention and its advantages will become more apparent from the following description of several embodiments given by way of non-limiting examples, with reference to the accompanying drawings, in which:

[0026] Fig. 1 is a schematic view of a management device according to a preferred embodiment of the invention. Description of the implementation methods

[0027] With reference to [Fig.1], the power management device of a local network 1 according to the invention is connected to a low voltage network 2 via an input 3, preferably located downstream of the connection of an electricity meter 4. The low voltage network 2 delivers, for example, to the device 1 a single-phase or three-phase alternating voltage of 230 or 400 V, at a power, for example, of about 12 kVA.

[0028] The device 1 includes a local network power supply interface 5, which is configured to be connected to the local network electrical panel 6. The interface 5 is preferably configured to be the sole source of power supply to the electrical panel 6. The electrical panel 6 is preferably a "TGBT" type panel, for "General Low Voltage Panel". In another embodiment of the invention, it may also be a low-voltage sub-panel, positioned downstream of a "TGBT".

[0029] The device 1 further includes an islanding switch 7, preferably mechanical, of which a first terminal 7a is connected to the input 3, and a voltage sensor 8, disposed between the islanding switch 7 and the input 3.

[0030] Device 1 further includes an uninterruptible power supply (UPS) 9, that is, an uninterruptible power supply (UPS), located between a second terminal 7b of the islanding switch 7 and the local area network (LAN) power interface 5. The uninterruptible power supply 9 has an upstream side, on the side of the second terminal 7b, and a downstream side, on the side of interface 5, and ensures continuity of service to its downstream side in the event of a power outage from its upstream side. This function is, of course, limited in time and depends on the capacity of the uninterruptible power supply 9 and the LAN power consumption. Thus, if the LAN power supply fails, Uninterruptible power supply (UPS) allows the local network to be powered without interruption for an initial, predetermined period. This initial period is, for example, on the order of a few minutes, such as 5 minutes.

[0031] Device 1 further includes a central controller 10. The central controller 10 is configured to receive measurements from the voltage sensor 8, via known wired or wireless communication means, and to control the opening and closing of the islanding switch 7. When a failure of the low voltage network 2 is detected, for example via a voltage value below a certain threshold for a second predetermined duration, the central controller 10 commands the opening of the islanding switch 7, in order to switch Device 1 to "off-grid" mode.

[0032] To analyze the current state from the low-voltage network 2 in greater detail, the voltage sensor 8 can be supplemented by a current sensor and / or a frequency sensor, enabling the controller to make more informed decisions regarding whether or not to put the device into "off-grid" mode. The monitoring of the low-voltage network 2 can be carried out as described in French patent FR 3128167.

[0033] In "off-grid" mode, the local network is supplied by local energy storage means, and possibly by local energy production means.

[0034] To do this, the device 1 includes at least one domestic battery 11, and at least one bidirectional charging station 12 for an electric vehicle 13.

[0035] The domestic battery 11 is sized so as to be able to supply the local network for a third predetermined period, longer than the first predetermined period. The third predetermined period is, for example, between 24 and 48 hours.

[0036] The domestic battery 11, for example, has a power output of between 10 and 20 kW, and a capacity of between 40 and 50 kWh.

[0037] The home battery controller 11 is preferably connected to the uninterruptible power supply (UPS) 9, on the downstream side of the UPS 9, i.e., on the side of its connection to the local network interface 5. Thus, the UPS can be configured to maintain power to the battery controller for a predetermined period. This ensures that in the event of a network failure, the power supply to the home battery controller 11 is not interrupted, and that the home battery 11 can therefore be used, via its controller, to contribute to the local network supply when the device 1 switches to "off-grid" mode.

[0038] In addition to the domestic battery controller 11, other domestic battery auxiliaries 11, such as ventilation, cooling or other systems, can be connected in the same way to the uninterruptible power supply 9, which allows the home battery 11 to be quickly operational when the device 1 is switched to "off-grid" mode.

[0039] Similarly, the charging station controller 12 and possibly other charging station auxiliaries 12 can be connected in the same way to the uninterruptible power supply 9, which allows the electric vehicle battery 13 to be quickly operational to supply the local network via the charging station 12 when the device 1 is switched to "off-grid" mode.

[0040] The auxiliaries of the domestic battery 11 and the charging station 12 are represented by the reference sign “18” on the [Fig.1].

[0041] Device 1 further includes a grid formation inverter 14. The grid formation inverter 14 is a bidirectional AC / DC inverter, which includes an AC input connected to the second terminal 7b of the islanding switch 7, and a DC output connected to the home battery 11 and the bidirectional charging terminal 12. The converter 14a partially behaves as a synchronous generator, delivering a voltage and frequency for the grid. The grid formation inverter 14 can therefore be used to restore a grid during a total power outage of the low-voltage grid 2, in a so-called "Black start" configuration.

[0042] Thus, in the event of a partial or total interruption of the low voltage network 2, the network formation inverter 14 is capable of restoring an electrical network, in which the domestic battery 11 and / or the electric vehicle battery 13 are used to supply the local network.

[0043] The converter 14a of the grid forming inverter 14 can also be connected downstream of the uninterruptible power supply 9, i.e., on the same side as the local grid, so that the uninterruptible power supply 9 can maintain the power supply to the converter 14a for a certain period. Thus, in the event of a partial or total interruption of the low-voltage grid 2, the auxiliaries of the grid forming inverter 14, and in particular its dedicated controller, and possibly its ventilation, cooling system, etc., can be powered during a transition period by the uninterruptible power supply 9.

[0044] The charging station 12 can be connected to the grid forming inverter 14 via a DC-DC converter, allowing the current and voltage to be prepared for fast charging of the electric vehicle 13.

[0045] In a particular embodiment of the invention, the central controller 10 is configured to control a grounding switch 15, preferably mechanical, located at the electrical panel 6. When the device 1 is put into "off-grid" mode, in particular by opening the islanding switch 7, the central controller 10 can control the closing of the earth switch 15, in order to ground the electrical panel 6.

[0046] The invention makes it possible to optimize the use of energy available in the home battery 11 and the electric vehicle battery 13. The central controller 10 can be connected, via wired or wireless communication, on the one hand to the battery controller (or battery "EMS," for "energy management system"), and on the other hand to the charging station 12, to perform this optimization. Thus, in "off-grid" mode, the central controller 10 can take into account the charge level of these batteries and their respective draw-off capacity in order to intelligently use the amount of energy they contain.

[0047] Specific configurations can be imposed on the central controller 10, and for example, it can be instructed to ensure that the battery of the electric vehicle 13 is fully charged every day at a certain time, or that it remains charged at all times, to allow for an unexpected departure at any moment. In "off-grid" mode, it may be preferable to keep the battery of the electric vehicle 13 fully or partially charged, so that the electric vehicle 13 can travel to recharge its battery outside of the device 1, in order to return energy to the device 1. This makes it possible to continue supplying the local grid in the event of a prolonged power outage, without being limited by the energy present in the home battery and the electric vehicle battery at the time of the outage.

[0048] The central controller 10 can be in communication with a voltage and / or current sensor 19 located at the electrical panel 6, in order to take into account the instantaneous consumption of the local network in the management of the device 1.

[0049] The device 1 may include an interface 15 to a photovoltaic system 16, connected to the grid-forming inverter 14. Thus, the photovoltaic system 16 can be used to charge the home battery 11, the electric vehicle battery 13, or to supply the local grid. One or more of these services can be provided by the system simultaneously. The central controller 10, which is then in communication with the photovoltaic system 16, is configured to take into account the amount of energy produced at each instant by the photovoltaic system 16, in order to decide on the optimal way to use it.

[0050] In another embodiment of the invention, the photovoltaic installation 16 can be directly integrated into the device. It can be connected to the grid-forming inverter 14 via a DC-DC converter, allowing adjustment of the current and voltage downstream of the grid-forming inverter.

[0051] The central controller 10 can be connected to a communication network 17, in order to allow remote management and / or monitoring of the device 1. Remote management makes it possible in particular to synchronize the management of a plurality of devices 1, or to take into account in the management of device 1 the state of other elements connected to the low voltage network 2. In addition, remote communication makes it possible to predict production by retrieving, for example, weather forecasts.

[0052] The invention allows, when the device 1 is in "on-grid" mode, to manage the consumption of the site, for example by recharging the home battery and / or that of the electric vehicle during off-peak hours, and to discharge these batteries to absorb peak consumption during peak hours.

[0053] The device 1 according to the invention also allows for rapid charging of the electric vehicle 13, since energy can be directly drawn from the home battery 11, at an instantaneous power much higher than that delivered by the low voltage network 2.

[0054] The invention makes it possible, when the device 1 is in "off-grid" mode, to maintain the continuity of power supply to certain loads, and preferably to all the loads necessary for restarting the local network, using a single uninterruptible power supply 9, and therefore without resorting to a dedicated uninterruptible power supply 9 for each component. Thus, the local network can be continuously powered, with no interruption being necessary between the switch from "on-grid" mode, in which it is powered by the low-voltage network 2, to "off-grid" mode, in which it is powered by the home battery 11 and / or the electric vehicle battery 13, the transition step being ensured by the uninterruptible power supply 9.

[0055] The present invention is not limited to the embodiments described but extends to any modification and variant obvious to a person skilled in the art, within the limits of the appended claims. Furthermore, the technical features of the various embodiments and variants mentioned above may be combined, in whole or in part.

Claims

1. Demands Local area network power management device (1) integrating: - a network input (3); - a local network power interface (5); - an islanding switch (7) of which a first terminal (7a) is connected to the network input (3); - a voltage sensor (8), located between the low voltage network input (3) and the islanding switch (7); - an uninterruptible power supply (9) disposed between a second terminal (7b) of said islanding switch (7) and the power interface (5) of a local network, said uninterruptible power supply (9) being configured to maintain the power supply to the local network without interruption for a first predetermined period; - a central controller (10), configured to receive measurements from said voltage sensor (8) and open the islanding switch (7) when the measured voltage is below a certain threshold for a second predetermined duration; - at least one domestic battery (11) capable of supplying the local network for a third predetermined period, greater than the first predetermined period, and of reinjecting electricity into the network input (3); - at least one bidirectional charging station (12) for electric vehicle (13) connected to the home battery (11) so that the home battery (11) can be used to charge the electric vehicle (13) and, when an electric vehicle (13) is plugged in with sufficient charge, that a battery of the electric vehicle can be used to charge the home battery (11); - a grid forming inverter (14), comprising an AC input connected to the second terminal (7b) of said islanding switch, and a DC output connected to the home battery (11) and the bidirectional charging terminal (12), so that the power management device can operate in an islanding mode in which the home battery (11) and / or the electric vehicle battery (13) supply the power interface (5).

2. Management device (1) according to claim 1, characterized in that the central controller (10) is connected to a communication network (17) enabling the control of the power management device of a local network (1) in a balancing mode in which the islanding switch (7) is closed and the home battery (11) and / or the electric vehicle battery (13) are used to perform injection or withdrawal on the network input (3).

3. Management device (1) according to claim 1, characterized in that at least one of the loads enabling the local network to be re-energized in the event of a power outage, among the central controller (10), a backup circuit of the network formation inverter (14), the auxiliaries (18), the central controller (10), is connected downstream of the uninterruptible power supply (9), so as not to require an uninterruptible power supply for each component.

4. Management device (1) according to claim 1 or 3, characterized in that the central controller (10) is configured to close an earth switch (15) enabling the general supply of said local network to be connected to earth when the islanding switch (7) is open.

5. Management device (1) according to any one of claims 1 to 4, characterized in that the first predetermined duration is less than 5 minutes.

6. Management device (1) according to any one of claims 1 to 5, characterized in that the third predetermined duration is between 24 and 48 hours.

7. Management device (1) according to any one of claims 1 to 6, characterized in that the power of the domestic battery (11) is between 10 and 20 kW.

8. Management device (1) according to any one of claims 1 to 6, characterized in that the power of the domestic battery (11) is between 20 and 500 kW.

9. Management device (1) according to any one of claims 1 to 8, characterized in that the home battery (11) comprises a battery controller connected to the uninterruptible power supply (9), the uninterruptible power supply (9) being configured to maintain the power supply to the battery controller for a certain predetermined duration.

10. Management device (1) according to any one of claims 1 to 9, characterized in that it comprises an interface (15) to a photovoltaic installation (16), said interface (15) being connected to the grid forming inverter (14).

11. Management device (1) according to any one of claims 1 to 10, characterized in that it comprises a DC-DC converter, connected between the network forming inverter (14) and said bidirectional charging station (12).

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