39 results about "Reverse power flow" patented technology

The invention provides a power distribution network partitioning method and device, equipment and a storage medium. The method comprises the steps that firstly, a node voltage-reactive power sensitivity matrix and historical operation data of a distributed power supply are obtained, the structural distance between nodes is calculated, the historical data are normalized, the attribute similarity is obtained in combination with an attribute weight matrix, and the two are added to generate an electrical distance. Resolution parameters are dynamically adjusted according to reverse power flow intensity, and the parameters are increased when the power flow is enhanced to refine clusters. According to the method, the limitation that traditional partition depends on geographical proximity or simple parameters is broken through, accurate partition is achieved by quantifying electrical coupling and resource characteristics, the problem of poor connection in the cluster is solved, the on-site consumption capacity of new energy is effectively improved, the transmission pressure of a main network is reduced, and the method is suitable for large-scale popularization and application. And meanwhile, the fault recovery capability and the calculation efficiency of the power grid are enhanced, and the method is suitable for district power balance optimization in a high-permeability distributed power supply access scene.

The invention discloses a regional main transformer reverse heavy overload-oriented power distribution network collaborative reconstruction regulation and control method. The method comprises the steps of optimizing feeder reverse power flow based on matrix monitoring and optimal distribution, constructing a feeder power flow state matrix, an adjustable equipment state matrix and an adjustable weight matrix, and performing power optimal distribution on the reverse power flow; main transformer cooperative power transfer control is implemented according to main transformer operation state identification and power adjustment margin calculation; and establishing a power distribution network reconstruction multi-objective optimization model fusing feeder line reverse power flow management and main transformer cooperative power transfer, and solving through a second-order cone programming relaxation technology. The invention provides an effective main transformer reverse heavy overload treatment scheme, and through collaborative optimization of the network topology and the local regulation and control strategy, the main transformer reverse heavy overload level is significantly reduced, the network loss is reduced, the absorption capability of the power distribution network to the distributed power supply is improved, and the power distribution efficiency is improved. The problem of stable operation of the power distribution network under the background of high-proportion distributed new energy access is solved.

The application discloses a line loss treatment method based on low-voltage power grid multi-source data fusion, and belongs to the information technology field.The method is as follows: based on the power grid topological structure and the changed power supply access point, the power supply path is reconstructed; the reverse power flow characteristics of the frequency point are extracted to correct the node impedance matrix of the current power supply path, and the power supply access point impedance parameter set is obtained; the power transmission path is updated through the reverse power flow characteristics, and the power distribution characteristics are obtained; the line loss distribution prediction model is constructed by fusing the power grid topological structure, the current power supply path, the power supply access point impedance parameter set and the power distribution characteristics, and the line loss abnormal area is identified and treated. Through the implementation of the application, the influence of the factors such as the change of the transformer area topological structure, the change of the power supply access point and the load fluctuation on the line loss is not considered in the prior art, so that the predicted line loss distribution has a large error compared with the actual situation, and the line loss treatment effect is poor.

And adjusting the pulsating power component according to the action of a grid-connected inverter of the system. This power system is provided with: a DC link unit; and a system grid-connected inverter connected to the DC link unit and configured to be connectable to a single-phase AC power supply. The power conversion unit includes a downstream operation for converting AC power supplied from a single-phase AC power source into DC power and supplying the DC power to the DC link unit, and a reverse current operation for converting DC power supplied from the DC link unit into AC power and supplying the AC power to the single-phase AC power source. One or more DC power sources connected to the DC link unit and configured so as to be able to supply DC power to the DC link unit; a smoothing capacitor that is connected to the DC link unit and smoothes the DC voltage of the DC link unit; and one or more electrical devices that are connected to the DC link unit and consume the DC power supplied from the DC link unit, the electrical devices having a pulsating power adjustment function for adjusting a pulsating power component in accordance with the operation of the system grid-connected inverter and the voltage phase of the single-phase AC power source. The pulsating power component is a frequency component that is an integral multiple of two or more of the power supply frequency of the single-phase AC power supply, among DC power consumed by the electrical device.

To provide an inverter device that has an AC input terminal for a control power supply in addition to an AC input terminal for a main circuit, and can reduce the size of a configuration required for a noise filter function.SOLUTION: An inverter device of the embodiment includes: a first rectifier circuit that rectifies an AC voltage received from a power supply terminal for a main circuit and outputs it to a DC power supply line for the main circuit; a second rectifier circuit that rectifies an AC voltage received from a power supply terminal for control and outputs it to a DC power supply line for control; a diode that prevents reverse power flow from the DC power supply line for control to the DC power supply line side for the main circuit; a control power supply circuit that is connected to an inverter main circuit connected to the DC power supply line for the main circuit and to the DC power supply line for control, and that generates a control power supply voltage required for control of the inverter main circuit; and a filter circuit that is arranged in a power supply path common to both a power supply path from the first rectifier circuit to the control power supply circuit and a power supply path from the second rectifier circuit to the control power supply circuit.SELECTED DRAWING: Figure 1

The application discloses a V2G charging station control method and system based on reverse power flow suppression, equipment and a medium, relates to the technical field of power distribution network operation control and vehicle-to-grid interaction, and comprises the following steps: taking reverse power flow suppression as a priority, considering the active power, reactive power and vehicle SOC dynamic problems of the charging and discharging unit, constructing a station rolling optimization model, calculating the set values of the active power and reactive power of each charging and discharging unit according to the station rolling optimization model; when the power reverse sending at the point of common coupling is over the limit, the absorption task is allocated based on the fair weight and the reverse sending over-limit amount, and the active power set value is adjusted. By taking the suppression of the PCC reverse power flow as a priority and guaranteeing the operation target of the power distribution network and the station, the station rolling optimization model of the V2G charging station is constructed, the power quality, equipment life and operation compliance are guaranteed, the absorption task is proportionally allocated among the charging and discharging units according to the fair weight, the station-level power is ensured to return to the permitted interval in time, and the solving capacity and response speed for sudden disturbances are improved.

The present invention relates to an isolated bidirectional DC / DC converter and a control method thereof. By adjusting the resonant inductance on the primary side of a CLLC circuit to the secondary side and providing an auxiliary unit in the circuit, the converter can achieve both step-up and step-down conversion in both forward and reverse operation. Furthermore, the present invention analyzes gain characteristic curves under different loads and powers during forward and reverse power flow, and proposes a control strategy applicable to the full operating range. Combining the isolated bidirectional DC / DC converter with the full operating range control strategy can meet a wide range of voltage output applications and effectively achieve soft switching of the device even under light loads.

The invention relates to a graph theory-statistics combined modeling driven dynamic grouping control method for electric vehicles. The graph theory-statistics combined modeling driven dynamic grouping control method comprises the following steps: constructing a graph theory-statistics combined driven vehicle network bidirectional interaction model; the method comprises the following steps: carrying out subsystem division on a power distribution network, and constructing a two-stage series decision framework by adopting a centralized training and distributed execution framework based on a multi-agent depth deterministic strategy gradient algorithm so as to solve the problem of power distribution network electric vehicle grouping and power distribution network active and reactive power joint optimization; real-time adaptive dynamic grouping is carried out on the electric vehicles in each subsystem in the first stage of series decision, and vehicle network active-reactive joint optimization control is carried out based on a grouping result in the second stage; and constructing a multi-dimensional space dynamic evaluation model fusing time sequence fluctuation, voltage stability and reverse power flow constraint, and solving the evaluation model to obtain the maximum access capacity margin boundary of the photovoltaic grid-connected point. Compared with the prior art, the method provided by the invention can improve the node-level new energy margin of the power distribution network, optimize the voltage and reduce the network loss.

The disclosed computer-implemented method may include (i) detecting a battery condition of a wearable battery-operated device that indicates a threat to a battery's health and (ii) in response to detecting the battery condition, performing a battery-protection action by initiating a reverse power flow across a bidirectional connection from the wearable battery-operated device to a portable charging case that is designed to charge the wearable battery-operated device. Various other methods, systems, and computer-readable media are also disclosed.

The application provides a primary and secondary fusion column circuit breaker protection adjustment method, comprising: collecting voltage phase data and current waveform data from three-phase positions of a bus in real time, obtaining photovoltaic grid-connected point output proportion and reactive power injection amplitude sequence during low voltage ride through, and reading current district photovoltaic penetration from a district configuration file; according to the voltage phase data and the reactive power injection amplitude sequence, correcting phase offset of each period according to the change rule that reverse power flow gradually increases with the increase of output during photovoltaic output climbing, calculating the initial discrimination range of the maximum sensitivity angle of the directional element; taking the corrected discrimination angle width as an effective window for phase comparison, comparing the current bus voltage phase with the reactive power injection amplitude, identifying the phase pullback phenomenon caused by low voltage ride through, and extracting the phase swing characteristics of the bus voltage.

The invention provides a frequency stability control method and system for a pulse load ship electric isolated network, and the method comprises the steps: constructing an energy flow map of the ship electric isolated network, and configuring an isolated network shock wave transmission model; when a pulse load is detected, the model is used to predict the diffusion of a frequency energy shock wave, and a reverse power flow for dissipating the shock wave is reversely calculated. A pulse load node is used as a space focus, and a beam forming algorithm is used to decompose the reverse power flow into original power instructions added with phase delay parameters and distributed to a plurality of distributed energy storage units. And performing time domain shaping on each original power instruction through an inertia damping control model for simulating physical characteristics, generating a target power instruction with a stress relaxation attenuation characteristic, and driving and executing the target power instruction. According to the invention, the compensation power of the plurality of energy storage units is focused on a disturbance source in space, so that the technical problems of low frequency suppression efficiency and secondary oscillation caused by response lag and spatial non-focusing in a traditional control method are solved.

An example method comprises receiving first historical meso-scale numerical weather predictions (NWP) and power flow information for a geographic distribution area, correcting for overfitting of the historical NWP predictions, reducing parameters in the first historical NWP predictions, training first power flow models using the first reduced, corrected historical NWP predictions and the historical power flow information for all or parts of the first geographic distribution area, receiving current NWP predictions for the first geographic distribution area, applying any number of first power flow models to the current NWP predictions to generate any number of power flow predictions, comparing one or more of the any number of power flow predictions to one or more first thresholds to determine significance of reverse power flows, and generating a first report including at least one prediction of the reverse power flow and identifying the first geographic distribution area.

The application provides a millisecond-level prediction suppression method and equipment for reverse power flow in a light storage and charging collaborative scenario, and relates to the technical field of smart grids. The method comprises the following steps: collecting in real time through an energy management controller; predicting a grid connection point according to multi-source operation data flow in combination with the light storage and charging collaborative scenario; presetting a reverse power flow threshold value, comparing the reverse power flow threshold value with a grid connection point net power trend; grading according to a reverse power flow risk index, formulating a collaborative suppression decomposition scheme; and respectively issuing power control instructions to perform millisecond-level prediction suppression of the reverse power flow. The application solves the technical problem in the prior art that only real-time power threshold values are relied on for triggering judgment, there is a lack of advanced perception of the grid connection point power change trend, protection actions can only be performed after the reverse power flow occurs, there is control lag, and the safety and stability of power grid operation are affected. The application changes reverse power flow control from post-disposal to proactive prevention and collaborative optimization, and ensures the stability of power grid operation.

The invention relates to an anti-circulation loss control method and system for a distributed photovoltaic station. The method comprises the following steps: acquiring a tidal current direction of a transformer of the distributed photovoltaic station; judging whether the tidal current directions of the first transformer and the second transformer are consistent or not, and if not, calculating distributed photovoltaic power generation adjustment power which needs to be adjusted from the transformer side with the reverse tidal current direction to the transformer side with the forward tidal current direction; based on the distributed photovoltaic power generation adjustment power, adjusting an inverter at a transformer side with a reverse tidal current direction so as to eliminate the circulating current influence; the power flow direction of each line is monitored in real time, the distributed photovoltaic power generation power of each transformer is dynamically distributed through the control loop, the consistency of the power flow direction is realized, and the loss caused by circulating current is avoided.

The present application relates to a kind of double reference point adaptive OLTC voltage regulating method considering reverse tide flow, comprising: real-time acquisition data in power grid;Calculate the reference voltage of each node of each feeder;Select feeder;Double reference point weighted average measured voltage value and double reference point weighted average reference voltage are calculated;Adaptive determination OLTC voltage regulating dead zone and dynamic delay;Adjust OLTC voltage regulating gear;Cyclic execution, realize whole process closed-loop adaptive OLTC voltage regulating.The present application can simultaneously solve the reverse tide flow overvoltage caused by high penetration rate photovoltaic access and traditional forward tide flow low voltage problem, realize multi-feeder coordinated voltage control;Through optimizing existing main transformer load tap changer control logic, stable voltage regulation can be realized, significantly reduce the investment of voltage regulating equipment and power grid transformation cost, effectively suppress voltage out-of-limit, improve power grid photovoltaic receiving capacity and system operation stability, prolong the service life of OLTC equipment, have strong engineering practicability and economy.

The invention belongs to the technical field of power system load prediction, and particularly relates to a short-term load prediction method for a power distribution network, and the method comprises the following specific steps: carrying out the classified collection of load-related data and influence factor data; performing scale unification on data of different dimensions by adopting Z-score standardization; splitting the load data into three parts through a time sequence decomposition algorithm; according to the method, the three-layer logic of data missing, reverse power flow deviation correction through feature decoupling, sample enhancement and fault tolerance improvement through dynamic correction is solved through component repairing, and the core problems that a traditional method is high in data quality dependence, poor in fault tolerance and insufficient in deviation correction are comprehensively solved. The whole process is carried out by restoring real load characteristics, a closed-loop anti-interference design is formed from data acquisition to prediction output, and it is ensured that an accurate load prediction result can still be output even in the scenes of electric meter faults, communication interruption and frequent reverse power flow.

The present invention relates to a photovoltaic system, and more specifically, to a photovoltaic system capable of preventing backflow that can increase the convenience of management while avoiding power disturbance in the grid by adjusting the connection with each photovoltaic device when the amount of power generated by the photovoltaic device exceeds the power consumption of the load.

The application relates to a kind of graph theory-statistics joint modeling driven electric vehicle dynamic grouping control method, constructs graph theory-statistics joint driven vehicle network two-way interaction model;Subsystems are divided to distribution network, and based on multi-agent deep deterministic policy gradient algorithm, using centralized training, distributed execution framework, constructs two-stage series decision architecture, to solve distribution network electric vehicle grouping and distribution network active and reactive power joint optimization problem;In the first stage of series decision, the electric vehicles in each subsystem are adaptively grouped in real time, and in the second stage, active-reactive power joint optimization control is carried out based on the grouping result;A multi-dimensional space dynamic evaluation model is constructed to integrate time series fluctuation, voltage stability and reverse power flow constraints, and the maximum access capacity margin boundary of the photovoltaic grid-connected point is obtained by solving the evaluation model.Compared with the prior art, the method can improve the new energy margin of the distribution network node level, optimize the voltage and reduce the network loss.

To provide a power storage device capable of suppressing a peak of reverse flow power to a power system.SOLUTION: A power storage device 15 includes a power storage section 15a and a charge / discharge control section 15b controlling the charge / discharge of the power storage section 15a. When it is predicted that surplus power, which can be derived by subtracting load power of a power load 14 provided in a facility 10 from power generated by a solar cell device 13, does not increase in a future predetermined charging permitted time zone, the charge / discharge control section 15b performs large power charging control of charging the generated surplus power into the power storage section 15a with the maximum charge power that can be charged in the power storage section 15a, during the whole period of the charging permitted time zone, and when it is predicted that the surplus power increases in the charging permitted time zone, the charge / discharge control section performs small power charging control of charging the generated surplus power with predetermined charge power smaller than the maximum charge power, at least early in the charging permitted time zone.SELECTED DRAWING: Figure 1

To realize reverse power flow transmission without causing any disadvantages to consumers. [Solution] A reverse flow control unit executes reverse flow transmission, transmitting power stored in a storage battery used by a consumer to the power grid during a reverse flow period that satisfies a predetermined reverse flow activation condition; and a compensation processing unit performs compensation processing to waive the cost of the consumer purchasing power transmitted from the power grid during a compensation period, which is the period during which power is transmitted from the power grid to the consumer after the reverse flow transmission is executed and until the amount of transmitted power becomes equal to the amount of power transmitted to the power grid during the reverse flow period, and to provide the consumer with a predetermined incentive. The power control system is configured to include the following.

The invention relates to a full-constraint shadow price information processing method based on electric power spot market parameters. The method comprises the steps of obtaining regional electric power spot market parameters; taking the sum of the total power generation cost, the trans-provincial power transmission cost and the cross-section power flow constraint out-of-limit penalty cost of the minimized power system as an optimization target, and taking the output of each unit, the power transmission power of each trans-provincial transaction component, and the forward power flow slack variable and the reverse power flow slack variable of each cross section meeting corresponding constraints as constraint conditions; establishing a regional electric power spot market clearing model; executing a solving operation on the regional power spot market clearing model to obtain shadow price information corresponding to the constraint condition and an association relationship between the regional power spot market parameters and the shadow price information; and outputting an abnormal electricity price tracing result according to the shadow price information and the association relationship. According to the above content, the method does not need to depend on manpower through the analysis and processing of the incidence relation, and improves the tracing efficiency of the abnormal electricity price.

A dynamic Stand-Alone Power System (SAPS) formation optimization system is developed to facilitate resilience in large utility sites with complex networks connected to multiple substations. The system ensures uninterrupted power to critical loads during substation outages while preventing reverse power flow (RPF). The system intelligently reconfigures the network at the feeder level and optimizes distributed energy resources (DERs). Operating in two phases, it first continuously evaluates how to form SAPS islands by allocating DERs to critical loads under current constraints, proactively preparing for outages and mitigating RPF risks. Once SAPS islands are formed, the system monitors and reassesses their configuration to improve service to critical loads. This adaptive and proactive approach enhances reliability and resilience in power distribution, ensuring essential operations are maintained even during disruptions.

The invention relates to the technical field of direct-current power supply and distribution and electric energy management, and discloses a large-model high-computing-power server power supply side waste heat electric energy recovery system which is characterized in that a waste heat power generation unit converts heat into direct-current electric energy; the recovery power conversion unit performs power conversion and forms recovery electric energy; the anti-reverse-flow isolation unit blocks reverse flow of power from the direct current bus to the recovery power conversion unit; the recovery control unit is used for acquiring data information, acquiring a reverse current detection result and a grid-connected end voltage detection result, and executing disconnection isolation, pre-charging grid connection and recovery; when the first condition is met, the anti-backflow isolation unit is disconnected, and output of the recycled electric energy to the direct-current bus is stopped; in the recovery process, the redundancy margin is determined, and the target recovery power output with the maximum net income is selected; and estimating open-circuit voltage and equivalent internal resistance, and adjusting an optimization step length and a preset reverse current limit value. According to the invention, stable and controllable grid-connected operation of waste heat recovery is obtained on the premise that the reliability of power supply is not reduced.

Provided is an air conditioning / hot water supply system capable of efficiently performing heat storage with respect to a hot water storage tank by using electric power from photovoltaic power generation, suppressing reverse power flow of the electric power to a system of a power company, and performing the heat storage with respect to the hot water storage tank at the same time as an air conditioning operation. To this end, the air conditioning / hot water supply system comprises: a heat source machine having a refrigeration cycle; an air conditioning device for performing air conditioning using the heat source machine as a heat source; a hot water storage unit having a hot water storage tank for storing heated hot water; a control device for causing a first hot water supply operation using the heat source machine as the heat source to be performed until the temperature of the hot water in the hot water storage tank reaches a first set temperature; and an electric heater for heating the hot water in the hot water storage tank. In a case where the air conditioning device is performing the air conditioning operation using the heat source machine as the heat source and the generated power of a photovoltaic power generation device is equal to or greater than reference power, the control device causes the electric heater to perform a second hot water supply operation for heating the hot water in the hot water storage tank until the temperature of the hot water in the hot water storage tank reaches a second set temperature obtained by adding an additional value to the first set temperature.

To prevent excessive restrictions on photovoltaic power generation due to output control from the grid side.SOLUTION: A photovoltaic power generation system is connected to the grid via the same service line, together with a power consumption facility. The system includes solar cells, a power conditioner that converts power between the solar cells and the grid, a reverse power relay that stops the operation of the power conditioner when reverse power flowing from the service line to the grid is detected, and a control device that receives an output control signal transmitted from a business operator that manages the grid. The control device normally disables the reverse power relay, and enables the reverse power relay when it receives the output control signal.SELECTED DRAWING: Figure 1

The amount of reverse power flowing into the power transmission and distribution network when the amount of generated power exceeds the amount of consumed power is suppressed to below a specified value. [Solution] In the control unit 11 of the management server 10 that constitutes the reverse power flow control system, the acquisition unit 111 acquires information on a predetermined first amount of reverse power flow, a second amount of power generated by the power generation equipment, and a third amount of power discharged from the charge / discharge equipment that charges and discharges the power generated by the power generation equipment. The reverse power flow control unit 113 then controls the reverse power flow for each combination of the second and third amounts of power, based on the first, second, and third amounts of power.

The present application relates to a kind of distributed photovoltaic carrying capacity calculation method considering reverse power flow, belong to distribution network evaluation field, solve the problem of voltage out of limit, transformer capacity out of limit and distributed photovoltaic capacity evaluation safety due to reverse power flow.It includes generating typical day uncertainty scenario, calculating the probability of uncertainty scenario under each typical day of season;Establish transformer model and reversible sending capacity model under bidirectional power flow mode;Based on the probability of uncertainty scenario under each typical day of season, and transformer model and reversible sending capacity model, build distributed photovoltaic carrying capacity calculation model including with the minimum of distribution network annual comprehensive resource loss as objective function, and the constraint condition of corresponding ESS and SOP collaborative planning considering reverse power flow;Based on typical day uncertainty scenario data, one-dimensional search is used to solve distributed photovoltaic carrying capacity calculation model, and the distribution network distributed photovoltaic carrying capacity calculation scheme is obtained.The accurate calculation of distributed photovoltaic carrying capacity is realized.

To provide a power storage device capable of suppressing a peak of reverse flow power to a power system.SOLUTION: A charge / discharge control section 15b included in a power storage device 15 derives time transition of a predicted value of surplus power that can be derived by subtracting load power of a power load 14 provided in a facility 10 from power generated by a solar cell device 13 in a future predetermined charging permitted time zone. The charging permitted time zone includes: a first time zone including a predicted maximum surplus time at which the surplus power is predicted to be at its maximum; and a second time zone earlier in time than the first time zone. In the second time zone, when the predicted value of the surplus power is larger than a predetermined target reverse flow power, the charge / discharge control section charges power, which can be derived by subtracting the target reverse flow power from the predicted value of the surplus power, in the power storage section 15a up to the maximum charging power that can be charged in the power storage section 15a, and when the predicted value of the surplus power is equal to or less than the predetermined target reverse flow power, the charge / discharge control section does not charge the power storage section 15a, but charges power same as the predicted value of the surplus power in the power storage section 15a up to the maximum charging power in the first time zone.SELECTED DRAWING: Figure 1

The invention belongs to the technical field of power system control, and discloses an intelligent control method, system and device for reverse power flow overload suppression of a distributed photovoltaic cluster, and a medium. The method comprises the following steps: acquiring key operation parameters of a power distribution network in real time; dynamically adjusting a safety threshold value of the load rate of the transformer according to the key operation parameters collected in real time; according to key operation parameters collected in real time, a reverse power flow safety threshold value is dynamically adjusted; on the basis of the current operation parameters and the dynamically adjusted load rate safety threshold and reverse power flow safety threshold, calculating the required photovoltaic output reduction amount by using an optimization control algorithm; and sending the calculated reduction quantity instruction to a distributed photovoltaic inverter or a photovoltaic cluster energy management system through a communication interface, and executing power regulation. The minimum photovoltaic output reduction amount is accurately calculated, excessive reduction caused by traditional fixed threshold value control is avoided, the absorption and utilization rate of photovoltaic power generation is improved to the maximum extent, and the light abandoning loss is reduced.

The application provides a reverse current processing method, system, device and medium of a three-phase power distribution network, belonging to the technical field of energy storage control. The method is applied to an energy storage system including multiple energy storage devices and a three-phase electric meter, control instructions are issued to the nth energy storage device based on a preset detection sequence to increase the output power; in the case that the nth energy storage device receives the control instructions, the power change data of each phase of the grid side is obtained through the three-phase electric meter, and the access phase corresponding to the nth energy storage device is determined based on the power change data; after determining the access phase of each energy storage device, if a reverse current signal is detected, the energy storage device with the access phase being the reverse current phase is selected based on the corresponding reverse current phase, the reverse current processing strategy is determined, and the operating parameters of the corresponding energy storage device are adjusted. The method realizes accurate identification of the access phase of multiple energy storage devices and reverse current positioning, reduces the phase misjudgment rate, and improves the operating stability and control efficiency in the home energy storage and grid connection scenario.