Device for managing the supply of power to a local grid

Abstract

The invention relates to a power supply management device (1) incorporating a grid input (3); a power supply interface (5) for supplying power to a local grid; an islanding switch (7); an uninterruptible power supply (9); a central controller (10); at least one domestic battery (11); at least one bidirectional charging terminal (12) for an electric vehicle (13), connected to the domestic battery (11) so that the domestic battery (11) is able to be used to recharge the electric vehicle (13) and, when an electric vehicle (13) is plugged in with enough charge, a battery of the electric vehicle is able to be used to recharge the domestic battery (11); and a grid-forming inverter (14) so that the power supply management device is able to operate in an islanding mode in which the the domestic battery (11) and / or the battery of the electric vehicle (13) supply power to the power supply interface (5).

Description

Local area network power management device

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

[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 (off-grid mode), and when the local network is supplied by one or both of the aforementioned batteries (on-grid mode).

[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 powered without using the external distribution network.

[0006] Document US11011913 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 power to the local grid when islanding 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 local network to be supplied without interruption.

[0008] The present invention aims to address this technical problem by proposing a local network power management device integrating: - a network input, configured to be connected to a public electricity network; - a power supply interface for critical loads of the local network; - an islanding switch, the first terminal of which is connected to the network input; - a first voltage sensor, disposed between the network input and the islanding switch; - an uninterruptible power supply disposed between a second terminal of said islanding switch and the first power supply interface of the local network, said uninterruptible power supply being configured to maintain the power supply of the critical loads of the local network without interruption for a first predetermined period;- a central controller, configured to receive measurements from said first voltage sensor and open the islanding switch when the measured voltage is below an islanding threshold for a second predetermined duration shorter than the first predetermined duration; - at least one domestic battery, with a power strictly less than 50 kW, capable of supplying the local network for a third predetermined duration; - at least one bidirectional electric vehicle charging station connected to the second terminal of said islanding switch so that the domestic battery can be used to charge the electric vehicle and, when an electric vehicle is plugged in with sufficient charge, that a battery of the electric vehicle can be used to charge the domestic battery;- a grid forming inverter, comprising an AC terminal connected to the second terminal of said islanding switch, and a DC terminal 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 optimizes battery usage since, in normal operating mode, the home battery can be used to supplement the power supplied to the grid input to power the charging station and enable rapid charging of the electric vehicle. Furthermore, critical loads benefit from an uninterrupted power supply regardless of any disruptions on the public electricity grid.

[0010] Furthermore, in islanding mode, the home battery can be supplemented by the electric vehicle's 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 using the electric vehicle's battery, thus theoretically guaranteeing a local grid supply for an unlimited duration, provided that the electric vehicle's battery capacity is sufficient to meet the local grid's demand.

[0011] Between normal operating mode and islanding mode, the uninterruptible power supply (UPS) ensures the continuous power supply to critical loads on the local network. This UPS is also preferably used to power certain components of the power management device of the invention, including 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. Uninterruptible power supplies (UPS), such as those positioned downstream of the grid forming inverter, can filter the electrical signal entering the local network and guarantee its quality even in islanded conditions.

[0013] In addition to normal and islanding modes, a preferred embodiment of the invention also allows the batteries to be used to implement a balancing mode. In this embodiment, the way the central controller manages the power management device depends on how the home battery and / or the electric vehicle battery are used. More specifically, in this mode, the central controller is configured to be able to control the power management device of a local grid in a balancing mode where 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.In the first operating mode, corresponding to the first type of balancing, the central controller is connected to a device that measures the characteristics of the electrical signal from the network, specifically its voltage and frequency. In the second operating mode, corresponding to the second type of balancing, the central controller communicates with the network operator via a communication network. It then controls the balancing mode based on instructions sent by the network operator.

[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's meter to command the local grid power management device to charge and discharge the batteries at the appropriate times. For example, the grid power management device can be commanded to: - charge the batteries when grid electricity is inexpensive, without exceeding the maximum permissible contracted power on the local grid; and - use the batteries to supply the local grid when grid electricity is expensive.

[0015] In the case of a domestic installation, the local grid's needs can sometimes exceed the power that the grid can deliver, causing power outages or limitations. This can occur, in particular, if the electrical power subscribed to by the consumer and measured at the installation's meter is temporarily lower than the power drawn, or more generally if the characteristics of the local grid connection do not allow the local grid to draw all the power it needs, at least temporarily.

[0016] To address this type of situation, the central controller can be configured to receive a measurement of the electrical signal power at the grid input and to control the management device in an overload absorption mode. In this mode, when the power supplied by the grid is less than the local grid's needs, the home battery and / or the electric vehicle battery are used to supplement the local grid. When the central controller detects an overload situation—that is, a situation where the local grid's consumption exceeds a set or measured threshold—it controls the grid shaping inverter to inject the necessary power into the local grid to absorb the overload. This energy is drawn from the home battery and / or the electric vehicle battery.

[0017] Thanks to these provisions, the device according to the invention allows optimal use of electrical energy resources from the network, stored in the home battery and in the electric vehicle battery, in "on-grid" mode as well as in "off-grid" mode.

[0018] 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 typically corresponds to a domestic network.

[0019] At least one of the loads enabling the local network to be restored in the event of an outage, among the central controller, the backup circuit of the network forming inverter, and the auxiliaries of the home battery and / or the charging station, may be connected downstream of the uninterruptible power supply, so as not to use an uninterruptible power supply for at least one of these loads.

[0020] The central controller can be configured to close at least one neutral-ground switch, thereby connecting the neutral of the second terminal of the islanding switch to ground when the islanding switch is open. This allows for automatic grounding, ensuring the safety of the local network. In a particular embodiment of the invention, this neutral-ground switch can be directly integrated into the device.

[0021] The second predetermined duration can be less than 10 seconds, which is sufficient time 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.

[0022] The third predetermined duration can be between 24 and 48 hours, which is generally sufficient to restore the public network following a network outage.

[0023] The power of the domestic battery is strictly less than 50 kW, for example between 5 and 20 kW, which is a power particularly suited to a conventional domestic network.

[0024] The said management device may include an interface to a photovoltaic installation, said interface being connected to the grid forming inverter, which allows 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 the energy from the public grid.

[0025] The management system may include a second interface for supplying non-critical local grid loads, connected to the second terminal of the islanding switch. The central controller is configured so that, if the islanding switch is opened, it commands the grid shaping inverter to supply the non-critical local grid loads via the inverter's AC terminal. Thus, all loads are supplied in "off-grid" mode, but only critical loads receive uninterruptible power. This allows for optimal sizing of the uninterruptible power supply, as an interruption of power to some loads for, for example, one second is not detrimental, while still ensuring the entire local grid is powered when islanding mode is properly activated.

[0026] The present invention also relates to a method of using a management device according to the invention, comprising the following steps: - supplying the critical loads of the local network from the public electricity network; - measurement by the first voltage sensor of a voltage below said islanding threshold, sign of disturbances on the public electricity network, leading to the activation of the uninterruptible power supply, in order to avoid an interruption of the supply of the critical loads - measurement by the first voltage sensor of a voltage below said islanding threshold for a second predetermined duration; - opening of the islanding switch, and switching of the network formation inverter from a network following mode to a network formation mode;- regulation of the voltage on the local network by the network forming inverter, using measurements from a second voltage sensor located at the second terminal of the islanding switch, - measurement by the first voltage sensor of a voltage above a connection threshold for a fourth predetermined duration, resulting in the closure of the islanding switch, - supply of critical loads of the local network by the public electricity network.;

[0027] This process may also include, just before the islanding switch closing step, a step of synchronizing the voltage and / or frequency of the network inverter to the voltage and / or frequency of the public electricity network.

[0028] This process may include, after the islanding switch opening step, a step of supplying non-critical loads from the local network by the home battery, via the network forming inverter.

[0029] 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:

[0030] This is a schematic view of a management device according to a preferred embodiment of the invention.

[0031] With reference to the diagram, the power management device for a local network 1 according to the invention is connected to a public network 2 via an input 3, preferably located downstream of the connection of an electricity meter 4. The public network 2 may be a low-voltage network, supplying, for example, to the device 1 a single-phase or three-phase alternating voltage of 230 or 400 V, at a power of, for example, approximately 12 kVA. The public network 2 may also be a medium- or high-voltage network.

[0032] Device 1 includes a first interface 5a for supplying critical loads from the local network, which is configured to be connected to the local network's electrical panel 6. Device 1 may also include a second interface 5b for supplying non-critical loads from the local network, which is configured to be connected to the local network's electrical panel 6. The first interface 5a, and optionally the second interface 5b, is preferably configured to be the sole source of power 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".

[0033] Device 1 further includes an islanding switch 7, preferably mechanized, of which a first terminal 7a is connected to the input 3, and a first voltage sensor 8, disposed between the islanding switch 7 and the input 3.

[0034] Device 1 also includes an uninterruptible power supply (UPS) 9, located between a second terminal 7b of the islanding switch 7 and the local area network (LAN) power interface 5. The UPS 9 has an upstream side, connected to the second terminal 7b, and a downstream side, connected to interface 5. It ensures continuity of service to its downstream side in the event of a power outage from its upstream side. This function is, of course, time-limited and depends on the capacity of the UPS 9 and the LAN power consumption. Thus, if the LAN power supply fails, the UPS maintains the LAN power supply without interruption for a predetermined period.The first determined duration is preferably less than 30 minutes, for example on the order of a few minutes, for example 5 min.

[0035] Device 1 further includes a central controller 10. The central controller 10 is configured to receive measurements from the first 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 public network 2 is detected, for example via a voltage value below an islanding 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.

[0036] To analyze the current state from the public grid 2 in greater detail, the first voltage sensor 8 can be a combined voltage and current and / or frequency sensor. This allows the central controller 10 to operate the device 1 in a grid balancing mode, in "on-grid" mode, and to make more informed decisions regarding whether or not to switch the device to "off-grid" mode. The monitoring of the public grid 2 can be carried out as described in French patent FR 3128167.

[0037] In "off-grid" mode, the local network is powered by local energy storage means, and possibly by local energy production means.

[0038] To do this, device 1 includes at least one domestic battery 11, and at least one bidirectional charging station 12 for an electric vehicle 13.

[0039] The domestic battery 11 is sized to be able to supply the local network for a third predetermined period. This third predetermined period is, for example, between 24 and 48 hours.

[0040] For example, the domestic battery 11 has a power output between 5 and 20 kW, and a capacity between 5 and 50 kWh.

[0041] The central controller 10 is preferably electrically connected to the output of the uninterruptible power supply (UPS) 9. This allows the UPS 9 to be configured to provide uninterrupted power to the central controller 10 for a predetermined period. This ensures that in the event of a grid failure, the power supply to the central controller 10 is not interrupted, and thus the grid shaping inverter 14 can effectively control the local grid supply when the device 1 switches to "off-grid" mode.

[0042] In addition to the central controller 10, the home 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 operational when the device 1 switches to "off-grid" mode.

[0043] 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 operational to supply the local network via the charging station 12 when the device 1 is switched to "off-grid" mode.

[0044] The auxiliaries of the domestic battery 11 and the charging station 12 are represented by the reference sign “18” on the.

[0045] Device 1 further includes a grid-forming inverter 14. The grid-forming 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 grid-forming inverter 14 can synchronize its frequency and voltage with that of the public electricity grid, in a "grid-following" mode, and deliver a voltage and frequency for a local network in a "grid-forming" mode. The grid-forming inverter 14 can therefore be used to restore a network during a total power outage of the public grid 2, in a so-called "black start" configuration.

[0046] Thus, in the event of a partial or total interruption of the public 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.

[0047] If the grid formation inverter includes an auxiliary power supply, which is not the case in all embodiments, this supply 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 power to the auxiliary supply for a certain period. Thus, in the event of a partial or total outage of the public grid 2, the auxiliary components of the grid formation 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.

[0048] The device preferably includes a second voltage sensor 20, which may be a combined voltage and current and / or frequency sensor, located at the second terminal 7b of the islanding switch 7. The second voltage sensor 20 is in communication with the central controller 10, which transmits information from the second sensor 20 to the network shaping inverter 14, so that the network shaping inverter 14 can regulate the voltage and frequency of the local network in "off-grid" mode.

[0049] In a particular embodiment of the invention, the central controller 10 is configured to control a neutral-earth switch 19, preferably mechanized, located at the second terminal 7b of the islanding switch 7. When the device 1 is put into "off-grid" mode, particularly by opening the islanding switch 7, the neutral of the electrical panel 6, according to the local network earthing scheme 1, may no longer be connected to earth. The central controller 10 can then control the closing of the neutral-earth switch 19, in order to ground the neutral of the electrical panel 6.

[0050] The invention optimizes 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, to the battery controller (or battery "EMS," for "energy management system") and 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 utilize the energy they contain.

[0051] Specific configurations can be imposed on the central controller 10. 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 to maintain a constant charge 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, allowing the vehicle to travel to recharge its battery outside of device 1 and thus return energy to device 1. This ensures continued power to the local grid in the event of a prolonged outage, without being limited by the energy present in the home battery 11 and the electric vehicle battery at the time of the outage.

[0052] The central controller 10 can be in communication with a third voltage and / or current sensor located at the electrical panel 6, in order to take into account the instantaneous consumption of the local network in the management of device 1.

[0053] Device 1 may include an interface 15 to a photovoltaic system 16, connected to the grid-linked 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 any given time by the photovoltaic system 16, in order to decide on the optimal way to use it.

[0054] 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.

[0055] The central controller 10 can be connected to a communication network 17, in order to allow remote management and / or monitoring of 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 public network 2. In addition, remote communication makes it possible to predict production by retrieving, for example, weather forecasts.

[0056] The device according to the invention can be used in a process comprising the following steps: - supplying critical loads of the local network from the public electricity grid; - measuring, by the first voltage sensor 8, a voltage below the islanding threshold, indicating disturbances on the public electricity grid. If the first voltage sensor 8 is also a frequency sensor, measuring a frequency outside a predefined range can also trigger the continuation of this step.From the first occurrence of such a measurement, the central controller 10 sends information to the uninterruptible power supply 9 to trigger an activation of the uninterruptible power supply 9, in order to avoid an interruption of the supply of critical loads; - measurement by the first voltage sensor 8 of a voltage below the said islanding threshold, or possibly of a frequency outside a predefined range, for a second predetermined duration; - opening of the islanding switch 7, controlled by the central controller 10, and switching of the network formation inverter 14 from "network following" mode to "network formation" mode.On this occasion, critical loads remain powered without interruption, or with a very short interruption, considered negligible within the scope of the present invention, for example, on the order of 20 ms; - regulation of the voltage, and possibly the frequency, on the local network by the grid forming inverter 14, using measurements from a second voltage and possibly frequency sensor 20 located at the second terminal 7b of the islanding switch 7; - measurement by the first voltage sensor 8 of a voltage exceeding a connection threshold for a fourth predetermined duration, indicating that disturbances on the public electricity network have ended. This measurement triggers the closure of the islanding switch 7, controlled by the central controller 10.Prior to this shutdown, the grid forming inverter 14 can operate a "synchrocoupling" with the public electricity grid, i.e., a synchronization of the voltage and / or frequency delivered by the grid forming inverter 14 with the voltage and / or frequency of the public electricity grid. This is achieved using measurements from the first voltage sensor and, optionally, the frequency sensor 8. The advantage of "synchrocoupling" is that the switchover from the grid forming inverter 14 to the public grid is transparent for all loads—the critical loads of the local network are supplied by the public electricity grid, thus the device 1 switches to "off-grid" mode.

[0057] When the local network 1 also includes non-critical loads, connected to a second power interface 5b, the above process may include, after opening the islanding switch 7, a step of supplying the non-critical loads by the home battery 11 and / or the electric vehicle battery 13.

[0058] The invention allows, when the device 1 is in "on-grid" mode, to manage the consumption of the site, for example by recharging the domestic battery 11 and / or that of the electric vehicle during off-peak hours, and to discharge these batteries to absorb peak consumption during peak hours.

[0059] Device 1 according to the invention also allows for fast charging of the electric vehicle 13, since the energy required for charging can be directly drawn from the home battery 11, at a higher instantaneous power than that delivered by the public network 2 alone.

[0060] 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

Local area network power management device (1) integrating: - a network input (3), configured to be connected to a public electricity network; - a power interface (5a) for critical loads of the local area network (1); - an islanding switch (7) of which a first terminal (7a) is connected to the network input (3); - a first voltage sensor (8), disposed between the 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 first power interface (5) of the local area network (1), said uninterruptible power supply (9) being configured to maintain the power supply of the critical loads of the local area network without interruption for a first predetermined period;- a central controller (10), configured to receive measurements from said first voltage sensor (8) and open the islanding switch (7) when the measured voltage is below an islanding threshold for a second predetermined period shorter than the first predetermined period; - at least one domestic battery (11) capable of supplying the local network for a third predetermined period, and of feeding electricity back into the network input (3), said domestic battery (11) having a power strictly less than 50 kW; - at least one bidirectional charging station (12) for electric vehicle (13) connected to the second terminal (7b) of said islanding switch (7) so that the domestic 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 domestic battery (11);- a grid forming inverter (14), comprising an alternating current (AC) terminal connected to the second terminal (7b) of said islanding switch, and a direct current (DC) terminal connected to the home battery (11) and to 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). Management device (1) according to claim 1, characterized in that the central controller (10) is configured to be able to control 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). Management device (1) according to any one of claims 1 or 2, characterized in that the central controller (10) is configured to receive a measurement of the power of the electrical signal measured at the network input (3), and to be able to control the management device (1) in an overload absorption mode in which, when the power delivered by the network is less than the needs of the local network, the home battery (11) and / or the battery of the electric vehicle (13) are used to supply the local network in addition to the public network. Management device (1) according to any one of claims 1 to 3, 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), the backup circuit of the network forming inverter (14), and the auxiliaries (18) of the home battery (11) and / or the charging station (12), is connected downstream of the uninterruptible power supply (9), so as not to use an uninterruptible power supply for at least one of these loads. Management device (1) according to any one of claims 1 to 4, characterized in that the central controller (10) is configured to close at least one earth-neutral switch (19) allowing the neutral of the second terminal (7b) of the islanding switch (7) to be connected to earth when the islanding switch (7) is open. Management device (1) according to any one of claims 1 to 5, characterized in that the second predetermined duration is less than 10 seconds. Management device (1) according to any one of claims 1 to 6, characterized in that the third predetermined duration is between 24 and 48 hours. Management device (1) according to any one of claims 1 to 7, characterized in that the power of the domestic battery (11) is between 5 and 20 kW. Management device (1) according to any one of claims 1 to 8, characterized in that it comprises an interface (15) to a photovoltaic installation (16), said interface (15) being connected to the grid forming inverter (14). A management device (1) according to any one of claims 1 to 9, characterized in that it comprises a second local non-critical load supply interface (5b) connected to the second terminal (7b) of the islanding switch (7), and in that the central controller (10) is configured so that in the event of opening of the islanding switch (7), the central controller (10) commands the network forming inverter (14) to supply the local non-critical loads via the alternating current (AC) terminal of the network forming inverter (14). A method of using a management device according to any one of claims 1 to 10, comprising the following steps: - supplying critical loads of the local network from the public electricity network; - measurement by the first voltage sensor (8) of a voltage below said islanding threshold, indicating disturbances on the public electricity network, leading to the activation of the uninterruptible power supply (9), in order to avoid an interruption in the supply of critical loads; - measurement by the first voltage sensor (8) of a voltage below said islanding threshold for a second predetermined duration; - opening of the islanding switch (7), and switching of the network formation inverter (14) from a network following mode to a network formation mode;- regulation of the voltage on the local network by the network forming inverter (14), using the measurements of a second voltage sensor (20) located at the second terminal (7b) of the islanding switch (7),- measurement by the first voltage sensor (8) of a voltage above a connection threshold for a fourth predetermined duration, resulting in the closure of the islanding switch (7),- supply of critical loads of the local network by the public electricity network.; A method of use according to claim 11, further comprising, just before the step of closing the islanding switch (7), a step of synchronizing the voltage and / or frequency of the network forming inverter (14) to the voltage and / or frequency of the public electricity network. Method of using according to any one of claims 11 to 12 a management device according to claim 10, comprising after the step of opening the islanding switch (7) a step of supplying the non-critical loads of the local network by the domestic battery (11), via the network forming inverter (14).

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