53 results about "Low voltage grid" patented technology

The invention provides a dual-mode-based low-voltage power grid state information management method and a dual-mode-based low-voltage power grid state information management system, belongs to the field of power line carrier communication, and solves the problem that the bit error rate is still high in some scenes. The method comprises the following steps: acquiring control harmonic characteristic parameters of grid-connected inverter equipment in a transformer area and physical layer state parameters of a high-speed power line carrier communication channel in the high-speed power line carrier communication channel; on a concentrator side or an edge node side, constructing an error rate risk assessment model based on the control harmonic characteristic parameters and the physical layer state parameters so as to identify a link risk state in which feedforward gain limitation and spectrum migration need to be executed; the method comprises the following steps: under the condition of determining that a control harmonic wave causes selective desensitization of a high-speed power line carrier communication front end based on a link risk state, applying feed-forward gain limitation to a high-speed power line carrier communication channel, and migrating a high-risk subcarrier to a low-risk frequency band; and a bypass relay path is established through the high-speed wireless radio frequency communication channel so as to transmit key data in the execution period.

The invention relates to the technical field of transformers, in particular to a signal transformer for multi-path signal coupling of a low-voltage power grid, the signal transformer comprises a magnetic core, an inlet wire winding and an outlet wire winding, efficient electromagnetic coupling and isolation of multi-path signals are achieved through the magnetic core, and a main control chip can send control signals to equipment through a driver and a coupling winding. And receiving an equipment feedback signal. The system can extract characteristics of a control signal and a feedback signal in real time, dynamically calculate a comprehensive crosstalk index, and adaptively adjust parameters of a receiving filter and a driver according to the comprehensive crosstalk index, so that signal crosstalk caused by physical coupling among multiple channels is effectively inhibited. According to the scheme, the structure is simplified, the system cost is reduced, the communication quality and the anti-interference capability of multiple paths of signals in a low-voltage power grid are remarkably improved, and the system is suitable for multiple occasions such as high-reliability power line communication.

The invention discloses an electric energy meter-oriented low-voltage power grid harmonic recognition algorithm optimization method, which relates to the technical field of power systems, and comprises the following steps of: respectively acquiring electric signals at a first sampling frequency and a second sampling frequency, constructing a high-frequency harmonic existence frequency list based on the electric signals acquired at the second sampling frequency, and constructing a high-frequency harmonic recognition algorithm based on a Nyquist sampling theorem. Whether a position locking instruction is triggered or not is judged, after the position locking instruction is received, a high-frequency harmonic existence frequency list is traversed, turn-back frequencies are calculated, energy accumulation is carried out on the same turn-back frequencies, an aliasing high-risk interval is constructed, high-order wavelet packet decomposition is carried out on the aliasing high-risk interval, and a candidate aliasing component sequence is obtained; and for each high-frequency harmonic frequency, calculating total turn-back pollution contribution energy at each turn-back position in the sampling channel under the condition of the first sampling frequency, and performing iterative correction on the candidate aliasing component sequence based on the total turn-back pollution contribution energy.

The invention discloses a low-voltage intelligent management and control device, particularly relates to the technical field of low-voltage power system management, and realizes accurate expression of a low-voltage power system structure through multi-level power network model construction and topology updating. Identifying a potential propagation path through fault feature vector extraction and graph neural network training; the risk probability of each path is predicted through the long-short-term memory network, and the fault risk prediction index is formed by combining the operation risk index and the electrical risk index, so that the problem that the fault is difficult to locate and block in time in the traditional low-voltage management and control is solved; performing priority protection on a key path through dynamic threshold regulation and control; the method can achieve the advanced prediction and active prevention and control of potential faults in a low-voltage power grid, reduces the chain loss caused by fault spreading, and improves the operation reliability and power supply safety.

The application discloses a kind of dynamic response 5G communication differential protection data transmission method, so that the differential protection service based on 5G communication is widely applied in low-voltage distribution network field, promote the development of new technology of power grid relay protection, solve the protection terminal of traditional low-voltage power grid not dependent on channel cannot give consideration to speed and selectivity requirement, by using advanced 5G communication technology, with the high bandwidth of 5G communication network, low latency and high reliability wireless communication environment, realize the large-scale application of longitudinal differential protection in closed-loop operation low-voltage power grid, improve the protection level of power grid.The application applies dynamic response transmission mode in the communication process of distribution network transmission line differential protection based on 5G communication, meets the rapidity requirement of relay protection, reduces 5G communication transmission flow, saves communication resources and reduces communication cost.

The invention discloses a high-voltage multi-section constant-current LED emergency lighting driving system and a control method. Relates to the technical field of power supply. Comprising LED lamp beads, an alternating current power supply part, an EPS power supply part and a driving IC. The alternating current power supply part and the EPS power supply part supply power to the same LED lamp bead through the same driving IC; according to the scheme, a traditional circuit structure is improved, the alternating current power supply part and the EPS power supply part supply power to the same LED lamp bead through the same driving IC, and the purposes of reducing cost and simplifying a circuit are achieved; wherein the alternating current power supply part accords with high-low voltage power grid input and meets sub-harmonic requirements; meanwhile, the EPS power supply part outputs constant voltage, the output power of the voltage changes along with the combination of the LED lamp beads, linear driving is shared to realize single-section constant current, and the purposes of reducing the cost and simplifying the circuit are realized on the premise of flexibly realizing EPS illumination application of different powers.

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.

The application belongs to the technical field of power systems, and discloses a low-voltage power grid operation state monitoring method and device, the method comprising: based on a pre-constructed Internet of Things architecture, obtaining operation state data of a target power grid device, and gathering the operation state data to a transformer area fusion terminal; processing the operation state data transmitted by the transformer area fusion terminal, and sending the processing result to a plurality of service terminals; in response to the processing result, each service terminal generates a cooperative monitoring result. The scheme of the application expands the dimension of low-voltage power grid state monitoring, expands the data volume, and improves the real-time performance of state monitoring.

Methods and systems for switch-on control or charging control of energy end-consuming electric devices. An example includes: connecting an electric device to a low-voltage grid; generating a uniquely coded consumer point identification on a grid section between an energy consumption meter and the connection point; detecting the identifier in a modulation signal; forwarding the identifier to t a control unit of the device; and sending an authorization request, either clearance to switch on to charge the electric device. A service offered by a provider connects, via an API module to the device as a client and transfers the identifier to the provider. The method automatically switches on or charges the electric device under contracted energy supply conditions for the energy cost optimization of the electric device.

The application provides a communication method and system based on HPLC and HRF double-mode fusion, and belongs to the field of power line carrier communication, and solves the problem of insufficient communication performance in a three-phase four-wire low-voltage power grid environment. The method comprises the following steps: in the high-speed power carrier communication channel of the three-phase four-wire power grid, the power phase of each terminal is learned dynamically through carrier coupling, an electric phase identification model is constructed, and the communication characteristics of the phase line to which each terminal belongs are recorded; in combination with the electric phase communication spectrum generated on the concentrator side based on the phase information of each terminal, the link isolation state between different phase lines is identified; in the case where it is determined based on the link isolation state that there is a cross-phase communication bottleneck, a preset cooperative packet sending optimization strategy is executed, and in the optimization process, a cross-phase relay path is established through a high-speed wireless communication channel.

The application discloses a new mine selective leakage protection method based on a standard current change trend and belongs to the field of coal mine low-voltage power grid fault diagnosis. In view of the problems that the commonly used selective leakage protection device has the problems of malfunction, misoperation, low-voltage switch leakage misoperation or step jump, and low line selection accuracy, the application proposes a mine selective leakage protection method based on a standard current change trend by connecting a switchable middle resistor in parallel with a zero sequence reactor of an additional direct current power supply device. Firstly, the zero sequence current flowing through the zero sequence reactor and each line before and after the input of the parallel middle resistor is obtained, the standard current of the zero sequence current of each line is obtained by taking the amplitude of the zero sequence current of the zero sequence reactor as a reference value, the change trend of the standard current of each line before and after the input of the middle resistor is compared, the standard current of the fault line shows an upward trend after the input of the middle resistor, while the standard current of the healthy line is unchanged, and finally the fault line selection is realized. The method has strong transition resistance capacity, only needs to measure the amplitude of the zero sequence current of each line, does not need to calculate the phase, is not affected by the phase measurement error and non-synchronous sampling, and is not affected by the transition resistance in principle.

The invention relates to a DC-DC converter for transferring energy from a high-voltage network into a low-voltage network. For this purpose, a circuit configuration is used which can be operated either as an active clamp flyback converter or as an active clamp buck converter.

The invention belongs to the technical field of phase modifier control, and particularly relates to a system suitable for starting a phase modifier and a control method.The system comprises a brushless doubly-fed motor or a doubly-fed motor coaxially connected with a high-capacity phase modifier, and the motor comprises a set of high-voltage windings and a set of low-voltage windings; the high-voltage winding and the low-voltage winding are respectively connected with a high-voltage power grid and a low-voltage power grid through contactors; the contactor connected with the low-voltage winding is connected with an inversion unit of a low-voltage four-quadrant frequency converter, and the inversion unit of the low-voltage four-quadrant frequency converter is connected with a step-down transformer. The method aims to assist in solving a series of problems existing in the turning, starting and synchronous grid connection processes of the current high-capacity phase modifier, and meanwhile, corresponding control strategies are formulated according to working conditions such as restarting at any rotating speed in the turning, static state starting and stopping processes of the phase modifier, so that the reliability of a phase modifier system is improved.

The application discloses a low-voltage network anomaly diagnosis method based on multi-source heterogeneous data fusion, relates to the technical field of low-voltage network anomaly diagnosis and operation and maintenance, and comprises the following steps: collecting multi-source data, pre-processing the data by edge computing, adjusting the collection interval according to changes, processing the data by deep learning and other technologies, converting according to semantics, improving formula standardization, fusing the data by federated learning, dynamically weighting and intelligently interpolating, constructing a rule base, optimizing by reinforcement learning, setting a dynamic threshold, training a model based on Transform and GNN, improving the effect by contrast learning, monitoring data in real time, warning in multiple ways when an anomaly occurs, assisting in troubleshooting by AR, and repairing the anomaly by a robot. The application can fuse multi-source heterogeneous data and improve data quality, the diagnosis model and the rule base are accurate and efficient, anomalies can be found in time, the operation and maintenance cost is reduced through intelligent early warning, AR-assisted troubleshooting and robot repair, the stable operation of the low-voltage network is ensured, and the economic and social benefits are remarkable.

The application discloses a kind of user terminal-oriented low-voltage power grid fault early warning method and system, belong to fault early warning technical field;In the process of low-voltage power grid operation, the environmental data around user terminal is collected in real time;Collect the real-time operation data of power grid equipment;The environmental data and the real-time operation data of power grid equipment are fused;Based on the data after fusion, the potential mode of power grid fault is identified, and the fault occurrence time is predicted;Fault early warning information and adjustment strategy are fed back to user terminal in real time, real-time monitoring load change after receiving feedback by user, and dynamic adjustment is carried out.The application further ensures that power grid can respond quickly when facing fault risk by dynamically adjusting load and equipment use, reduces the possibility of fault occurrence, thereby effectively improves the operation efficiency, stability and reliability of power grid.

An unlocking control system, comprising: an external power replenishment interface (4), which is configured to connect to an external emergency power source when a vehicle is in a low-battery-voltage state; a power source management module (1), which is configured to communicate with the external emergency power source, and measure the voltage of the external emergency power source, wherein if it is detected that the voltage matches the voltage of a low-voltage power network of a vehicle, the power source management module controls a secondary cut-off protection unit (3) to be turned on, such that a low-voltage storage battery (5) is connected to the external emergency power source so as to perform a power replenishment operation; the low-voltage storage battery (5), which is configured to supply power to the low-voltage power network of the vehicle; and a door module (6), which is configured to drive, once having obtained power supplied from the low-voltage storage battery (5) and when a vehicle door unlocking signal is received and the authentication of identity information of a user has passed, a door lock to complete unlocking. Further disclosed are an unlocking control method and a vehicle. On the premise of ensuring the convenience, reliability and anti-theft safety of a jump-starting operation of the vehicle, the system can enable a vehicle door to be opened, and then jump-start the low-voltage storage battery (5) of the vehicle and enable the vehicle to regain low-voltage power supply, so as to restore normal functions of an electrical system of the vehicle, thereby realizing a low-cost, highly-reliable and high-tech design, and making the customer experience more comfortable and safer.

The invention relates to a high-reliability station building low-voltage power supply system based on flexible interconnection, and belongs to the field of low-voltage power supply systems. According to the system, different low-voltage alternating-current buses in power distribution rooms are connected through a direct-current system, and interconnection between the power distribution rooms and between the power distribution rooms and a switching station is achieved through the direct-current system; the direct current system supplies power to the substation electricity in the switching station, the direct current screen in the switching station, the substation electricity in the power distribution room, the direct current screen in the power distribution room and the charging pile, and meanwhile the direct current system is matched with a storage battery pack. According to the invention, accurate and real-time compensation can be realized, and the power supply quality problems of three-phase imbalance and the like are solved; and low-voltage power grid autonomy is realized through the flexible direct current control system.

Residual current device (1) with a housing (2) extending along a longitudinal axis (5) in a longitudinal direction (6) from a network-side housing area (7) to a consumer-side housing area (8), wherein a network-side connection (3) for electrical connection to a low-voltage network is arranged in the network-side housing area (7) and a consumer-side connection (4) for electrical connection to one or more electrical consumers is arranged in the consumer-side housing area (8), wherein the residual current device (1) comprises a control unit (15) for detecting fault conditions, wherein at least one status indicator element (10, 10', 10'') controllable by the control unit (15) is arranged on the housing (2) for optical signaling of the presence of a fault condition, characterized in thatthat furthermore, at least one first display means (11) controllable by the control unit (15) and at least one second display means (12) controllable by the control unit (15) are arranged on the housing (2), wherein the control unit (15) is configured to generate an optical signal by means of the at least one first display means (11) when a fault condition due to a network-side fault is detected and to generate an optical signal by means of the at least one second display means (12) when a fault condition due to a consumer-side fault is detected.

The invention discloses a distributed photovoltaic bearing capacity assessment method and system considering medium and low voltage coupling. The method comprises the following steps: obtaining a topological structure and line parameters of a medium and low voltage power grid; selecting the electrical load and the photovoltaic output at the typical moment with the maximum photovoltaic output; calculating the power flow of the medium-voltage power grid to obtain the inlet voltage of each transformer area; calculating an upper limit critical moment difference of each transformer area; calculating the maximum photovoltaic installed capacity which can be accepted by each transformer area and the total photovoltaic installed capacity of the whole medium and low voltage power grid; replacing the original photovoltaic installed capacity with a calculation result, recalculating the maximum photovoltaic installed capacity which can be accepted by each transformer area and the total photovoltaic installed capacity of the whole medium and low voltage power grid until the total photovoltaic installed capacity of the whole medium and low voltage power grid converges, and obtaining a final value of the total photovoltaic installed capacity considering medium and low voltage coupling; and finally, carrying out equipment thermal stability checking. The method considers the coupling effect of the medium and low voltage power grid, has few iterations and high calculation efficiency, and is simple and easy to implement.

The invention discloses a low-voltage power grid insulation monitoring method and low-voltage power grid insulation monitoring equipment, a PT opening triangular part and a zero-sequence current transformer are specially configured for a 400V low-voltage power grid, and two paths of analog signals of zero-sequence voltage and zero-sequence current of the power grid are synchronously collected; the analog signals are transmitted to an acquisition processing circuit module, and are converted into zero-sequence voltage and zero-sequence current digital signals carrying vector phase angle digital quantity information through low-voltage filtering and analog-to-digital conversion processing; then the digital signal is transmitted to an MCU microcontroller module, calculation and separation are carried out through a built-in data analysis processing sub-module, and values of a resistive component and a capacitive component of the zero-sequence current are obtained; and judging whether the line has an insulation hidden danger or capacitive capacitance interference based on the two component values. Zero-sequence electric signals can be collected at high precision, distributed capacitance interference is weakened, and accurate detection and early warning of early-stage potential insulation hidden dangers in a low-voltage power grid are achieved.

Techniques for identifying at-risk low-voltage grid assets are described. At-risk transformers (and, in some examples) other devices, are identified if overloaded and actively providing power for electric vehicle (EV) charging. EV charging devices and / or EVs may be enrolled in a program wherein techniques are employed to reduce over-loading events at the at-risk devices. The techniques can involve EV charging management to reduce transformer overload. The techniques for detecting at-risk devices and enrolling EV-charging devices and / or other high-wattage devices can be used to protect transformers, secondary feeders, medium voltage lines, and substations.

A power electronic converter (1) with a plurality of power electronic converter cells (3) is shown and described, wherein each power electronic converter cell (3) has a high-voltage unit and a low-voltage unit, wherein the high-voltage units of the plurality of power electronic converter cells (3) are connectable to a high-voltage network (5), wherein the low-voltage units of the plurality of power electronic converter cells (3) are connectable to a low-voltage network (7), wherein the high-voltage units have a first neutral point (9) and the low-voltage units have a second neutral point (11), and wherein the first neutral point (9) and the second neutral point (11) are electrically connectable to a common neutral point.Furthermore, a method (100) for manufacturing a power electronic converter (1), in particular according to one of the preceding claims, is presented and described, comprising at least the following steps: providing a plurality of power electronic converter cells (3), wherein each power electronic converter cell (3) has a high-voltage unit and a low-voltage unit, connecting the high-voltage units to provide a high-voltage grid connection, connecting the low-voltage units to provide a low-voltage grid connection, and connecting the high-voltage grid connection and the low-voltage grid connection to a common neutral point.

The application provides a reverse current prevention method and device of a photovoltaic power supply system, a terminal and a storage medium. The method comprises the following steps: acquiring electric energy data of a low-voltage power grid in real time; subtracting the electric energy data at a previous moment from the electric energy data at a current moment to obtain an electric energy difference; if the electric energy difference is greater than a first preset threshold, adjusting a photovoltaic inverter based on the electric energy difference to reduce the output power of the photovoltaic inverter; if the electric energy difference is greater than a second preset threshold, controlling the photovoltaic inverter to stop; and if the electric energy difference is greater than a third preset threshold, controlling a contactor to be disconnected. The first preset threshold is smaller than the second preset threshold, and the second preset threshold is smaller than the third preset threshold. Through the above scheme, the application can perform hierarchical reverse current prevention control according to the size of a local load surge, thereby improving the reverse current prevention response speed and guaranteeing the interests of photovoltaic power generation users.

The invention discloses a power equipment operation condition monitoring device, solves the problem of insufficient monitoring coverage, and belongs to the technical field of power equipment monitoring. The inspection device comprises an inspection track, an inspection platform, an electricity taking assembly, a moving mechanism and a detection assembly, the moving mechanism drives the inspection platform to move in the inspection track, and the detection assembly is arranged below the inspection platform and used for performing multi-angle detection on the power equipment; the electricity taking assembly comprises a conductive sliding contact strip and an electric brush; the inspection platform is arranged in the inspection track, the conductive sliding contact strip is arranged on the inner side of the inspection track, the power distribution room low-voltage power grid supplies power to the conductive sliding contact strip, one end of the electric brush makes contact with the conductive sliding contact strip to take electricity, and the other end of the electric brush supplies power to the moving mechanism and the detection assembly. Through the arrangement of the inspection track, the inspection platform capable of moving on the track, and the moving mechanism and the power taking assembly for providing power for the inspection platform, automatic unmanned inspection of the power equipment is realized.

The invention discloses an energy consumption space-time distribution obtaining method based on a voltage network. In order to solve the problems of low carbon emission accounting precision, poor data timeliness and difficulty in hidden high-consumption link identification in the prior art, high and low voltage power grid differential modeling is adopted: a high voltage power grid realizes power supply-load carbon flow tracking through a Thevenin equivalent model and block matrix operation; and the low-voltage power grid adopts reverse complex power tracking and SVD dimension reduction to optimize the calculation efficiency. A multi-source data fusion technology is combined, a KNN algorithm is used for repairing electric signal data, an electricity-material dynamic association rule is mined through FP-Growth, and an equipment-level carbon intensity factor updated per hour is constructed. Spatial and temporal features are extracted based on an LSTM network, a three-dimensional carbon portrait is generated in combination with a contrast clustering algorithm, and abnormal high-consumption equipment is accurately recognized. According to the method, the data quality is optimized through a closed-loop feedback mechanism, and minute-level carbon emission dynamic monitoring and collaborative emission reduction decision making are supported.

The present application relates to the technical field of reactive power compensation, and discloses a kind of intelligent reactive power compensation system of low-voltage line of thermal power plant, including several intelligent reactive power compensation devices, deployment in the end of each low-voltage substation bus of thermal power plant, still include: setting module is used to set several compensation demand scene, and generates compensation control model, monitoring module is used to acquire the multi-source data set of monitoring point, generates the real-time state coefficient of corresponding monitoring point;Control module is used to judge whether corresponding monitoring point needs compensation based on real-time state coefficient, if yes, generates the compensation strategy of corresponding monitoring point;Optimization module is used to generate the application data package of compensation strategy, and generates the application evaluation value of compensation strategy, judges whether to generate optimization instruction, realizes the accurate identification of reactive power demand of low-voltage line of thermal power plant, dynamic response and continuous optimization, to improve the operation efficiency and power quality of low-voltage power grid of thermal power plant, meet the requirement of modern thermal power plant to reactive power management refinement, intelligent.

Techniques for identifying at-risk low-voltage grid assets are described. At-risk transformers (and, in some examples) other devices, are identified if overloaded and actively providing power for electric vehicle (EV) charging. EV charging devices and / or EVs may be enrolled in a program wherein techniques are employed to reduce over-loading events at the at-risk devices. The techniques can involve EV charging management to reduce transformer overload. The techniques for detecting at-risk devices and enrolling EV-charging devices and / or other high-wattage devices can be used to protect transformers, secondary feeders, medium voltage lines, and substations.

This invention discloses a strategy and apparatus for mitigating voltage exceedances in low-voltage distribution networks, relating to the field of low-voltage power grid technology. The strategy includes collecting outer-loop voltage data, inner-loop current data, inverter design parameter data, and energy storage battery data. Based on the outer-loop voltage data, inner-loop current data, and inverter design parameter data, it calculates reactive current reference data, the inverter's target total output current when outputting the reactive current reference data, and the inverter's target output AC voltage amplitude data. By adding an energy storage battery in conjunction with the inverter, when the inverter's own reactive power support is insufficient to stabilize the power grid, the energy storage battery provides additional reactive power support to the distribution network, improving the inverter's stability range against power grid fluctuations. Simultaneously, it analyzes the charging and discharging efficiency of the energy storage battery and the cost-saving effect caused by charging and discharging, minimizing the cost loss while ensuring grid voltage stability.

The application belongs to the technical field of comprehensive energy dispatching, and discloses a method for processing natural alkali by using wind-solar-storage complementary energy supply. Wind power generation, solar power generation, electrothermal energy storage and electrochemical energy storage are used as the energy supply system for natural alkali processing and production, the energy supply system is connected through high and low voltage power grid systems, effective transmission and conversion of power supply, energy storage and energy consumption side power are realized, and power balance and source-load interaction in the power grid are realized through an energy management center. Through an energy management and control system, source grid load storage is deeply integrated to realize "zero emission" of natural alkali processing carbon emission.

This application relates to a distributed energy system for small-scale industrial and commercial use, comprising a grid dispatch response module, an energy gateway, and distributed energy sources connected in sequence. The grid dispatch response module is also connected to an external grid control device for receiving and forwarding dispatch instructions issued by the grid control device. The energy gateway transmits the dispatch instructions sent by the grid dispatch response module to the distributed energy sources. The distributed energy sources are also connected to a low-voltage grid for changing their grid-connected operating mode according to the dispatch instructions. This solves the problem of not being able to flexibly adjust power generation according to the actual needs of the grid. It enables the distributed energy sources to receive dispatch instructions from the local grid through a communication module and the energy grid, flexibly adjust the energy delivered to the grid, and improve the quality and stability of grid operation.