562 results about "Black start" patented technology

A method and a system are described for island operation of at least two wind turbines associated with a wind farm, wherein said wind farm is configured for providing power generated by wind turbines in said wind farm to a main grid and wherein the method comprises: detecting at least two or more deactivated wind turbines in said wind farm, said deactivated wind turbines being disconnected from said main grid; configuring at least one islanded local grid for electrically connecting said two or more deactivated wind turbines; activating at least one of said deactivated wind turbine using a black start operation; and, connecting said at least one activated wind turbine and at least one of said deactivated wind turbines to said local grid, said activated wind turbine acting as a power supply for said at least one deactivated wind turbine connected to said local grid.

A combined heat and AC power generating system is disclosed having black start capability for the full time, simultaneous production of both electricity and heat. Heat generated within the system is captured and used for heating applications such as heating building air and tap water. The power generating system comprises an engine, generator, rectifier, variable frequency drive inverter, and inverter control electronics. The system provides improved efficiency and prolonged engine life by always operating the engine with its throttle fully open to obtain maximum efficiency and the engine is normally operated near its stall point. In this operating state the inverter control electronics adjust the power output from the inverter to control the speed of the engine. This is done by increasing the power output from the inverter when the power drawn by the load decreases. This causes the engine to operate closer to its stall point and it slows down. The power from the inverter is decreased when the power drawn by the load increases. This causes the engine to operate further from its stall point and it speeds up. The slight power changes to facilitate this operation will always be drawn from or distributed to the electric utility grid so there is no wasted power. The inverter control electronics are responsive to signals from loads such as refrigeration loads to cause the frequency of the inverter output to change to permit the refrigeration load to operate more efficiently.

The invention relates to an on-line large power grid recovery assistant decision-making system. The system comprises two work modes, namely a real-time assistant mode and a research and analysis mode, a fracture surface operation analysis module, a calculation configuration module, a calculation function module and a calculation management module, wherein the fracture surface operation analysis module is used for fracture surface reading and fracture surface adjustment, the calculation configuration module is used for setting calculation parameters and selecting a black-start power supply and a started power supply, the calculation function module is used for system partitioning, load flow calculation, electromagnetic transient calculation, electromechanical transient calculation and path search and assessment, and the calculation management module is used for displaying system partitioning schemes, voltage waveforms, ranking of available paths and a black-start generating scheme. When the on-line large power grid recovery assistant decision-making system is used for developing an on-line electric power system recovery assistant decision-making supporting system, existing data resources in a dispatching center can be sufficiently utilized, the advantages of the method of pre-arranged scheme recovery and intelligent dispatching are combined, a model does not need to be rebuilt, the construction time and cost of the system are reduced, the real-time performance and the accuracy of suggestions to decision-making are improved, and a powerful support is provided for rapid and reliable recovery of a power grid after power outages.

The invention discloses a modular multilevel converter high voltage direct current (MMC-HVDC) converter station starting method used for a power network black start and belongs to the technical field of power transmission and distribution. The technical scheme is that corresponding starting method and strategy are provided aiming at a two-end system and a multi-end system, wherein the method and strategy for the two-end system converter station black start comprise the steps of firstly, starting an active side converter station, closing a direct current transmission line disconnecting link, and charging a passive side converter station at the same time, secondly, carrying out charging in an alternation cycle sorting conversion mode, locking the converter station for a short time when pre-charging is finished, and finally, unlocking the converter station, placing a constant alternating-current voltage controller and fishing start-up. The method and strategy for the multi-end system converter station black start comprise the steps of respectively connecting a resistance (Rx) with positive and negative electrodes on the outlet side of each end of the multi-end system in series on the basis of the steps of the start-up of the two-end system and guaranteeing that the black start can be carried out at any ends with other ends keeping in stable operations. Therefore, reliability of power supply is guaranteed.

The invention discloses a smart central strategy control system for a micro-grid. The smart central strategy control system for the micro-grid comprises a micro-grid electrical system. The micro-grid electrical system comprises a distributed electricity generation unit, an energy storage unit, an environment monitoring unit, a simulation load unit, an actual load unit, a communication network unit and a central strategy control unit. The smart central strategy control system for the micro-grid further comprises an information collection system unit and a central control processing unit. According to the smart central strategy control system for the micro-grid, overall control, coordination and optimization of electricity generation equipment, electricity consumption equipment and electricity consumption quality of the micro-grid can be achieved, the intermittent energy electricity generation plan, the load electricity consumption plan, load control, energy storage, the diesel engine electricity generation plan and the like are involved, and the functions of emergency electricity consumption control, automatic grid-connected/grid-disconnected switching control, adverse current prevention control, black-start control, peak load shifting, time shifting and the like of the system can be achieved. In communication, the smart communication detection technology and the channel hot standby redundancy technology are adopted additionally, and the stability and the reliability of communication are guaranteed.

A multi-agent-based urban power grid isolated island black-start system and method belongs to the field of operation control of power system field. A plurality of units which can achieve splitting isolated island operation are configured in main power plants in advance, the units are required to be capable of supplying first-class and second-class loads or providing start capacity of other power plants after undertaking auxiliary power load and can guarantee stable operation of auxiliary powers after emergency load shedding; when a power grid system suffers from large disturbance or has a major fault, transformer substation monitoring agents of an affected area and power plant monitoring agents can actively split into isolated island operation states, when the fault is finally evolved into a blackout, all the stable-operation power plant stage and transformer station stage isolated islands in the power grid report respective isolated island operation conditions to a power grid monitoring center agents. The multi-agent-based urban power grid isolated island black-start system and method can greatly shorten power grid black-start time and reduces economic losses and social influences caused by the blackout.

A method to control a voltage source converter in a HVDC system includes controlling a frequency and a voltage amplitude of an AC voltage generated by the voltage source converter independently of the conditions in an AC network connected to the voltage source converter. The method is performed by a control unit of an HVDC system. The method may form a basis of a method to black start an AC network. The AC network includes transmission lines and is connected to at least two AC power stations. One of the at least two AC power stations is connected via a HVDC system to the AC network.

The invention relates to an electric power system net rack reconstruction optimization method capable of considering a microgrid as a black-start power supply. The method comprises the following stepsthat: inputting electric power system parameters; taking the maximum recovery of the power generation capacity of the system and the minimization of a load loss amount in the microgrid as targets toconstruct a net rack reconstruction optimization model capable of considering the microgrid as the black-start power supply; determining the constraint condition of the net rack reconstruction optimization model capable of considering the microgrid as the black-start power supply; on the basis of a node importance degree and path recovery time, constructing a synthesis path evaluation index to optimize the recovery path of a unit to be recovered; and jointly combining a bee colony algorithm with a quantum theory to solve the model. A net rack reconstruction strategy which adopts the microgridwhich contains high-ratio renewable energy sources as the black-start power supply has certain feasibility and effectiveness. Under a situation that the conventional black-start resources of the system are insufficient, the microgrid can be taken as the black-start power supply to provide starting power for non-black-start units, and the non-black-start units can be quickly recovered to achieve apurpose of net rack reconstruction.

The invention discloses a method for restoring sequence and path of a unit and simultaneously performing optimization. The method includes: 1) obtaining data required by optimization calculation; 2) confirming a black-start power source which is safe and reliable to operate, selecting a unit with proper capacity and around an important load to serve as a set of units to be restored; 3) building a multi-objective optimization mathematical model for optimizing unit restoring sequence and unit restoring path simultaneously by considering mutual influence of unit restoring sequence optimization and unit restoring path optimization, leading in DE-EDA for solving, and giving a plurality of Pareto optimized unit restoring sequences and unit restoring paths and putting sequence of lines in the path; 4) performing various safety verifications on obtained Pareto optimized restoring schemes by adopting a numerical simulation technology; 5) enabling decision makers to choose one scheme as a main restoring scheme from the verified Pareto optimized schemes, and using other schemes as backup restoring schemes.

The invention provides a method and a system for controlling a battery energy storage power station of supporting black start of a light-preserved power generation system. The method comprises steps of obtaining power station data including power grid operation states, load types, photovoltaic output values, load power values and energy storage current transformer charged states; determining whether or not a power grid has a fault according to the power grid operation state; when the power grid has a fault, calculating the number of energy storage current transformers for charge-discharge power distribution according to the photovoltaic output values and load power values and using the current transformer power optimization principle; and establishing a light-preserved combined power generation output optimal objective function, and determining the power of each energy storage current transformer for charge-discharge power distribution according to the load power values, the photovoltaic output values and the charged states of the energy storage current transformers for charge-discharge power distribution. The invention achieves black start of a power grid through a battery energy storage system combined with a photovoltaic electric field when the power grid has a fault, and achieves control of stable operation of the power grid.

The invention provides a test method for validating the black start ability of a hydroelectric generating set, relating to the test method for a hydroelectric generating set and aiming to provide a test method for validating the black start ability of the hydroelectric generating set under the circumstance of unexpected power failure due to an accident of a power network. The method comprises the following steps in any sequence that: the black start ability of excitation equipment is validated by the test; the black start ability of a speed controller and an oil hydraulic system is validated by the test; the black start ability of auxiliary equipment of the generating set is validated by the test; the ability of the generating set to protect self when the black start is not successful is validated by the test; and the black start ability of the generating set is evaluated. The test method provides a basis for the black start operation in case of the accident, avoids the expansion of the accident because the black start operation is performed on the hydroelectric generating set without the black start ability, and is suitable for a hydraulic power plant or a hydraulic station to stimulate and validate whether the hydroelectric generating set has the black start ability.

The invention discloses a method for rapid self-healing of a power grid. The method comprises the following steps of: obtaining operation data of all machine units in the power grid, and establishing mathematic models of all the machine units; determining a starting sequence of non-started machine units and searching for power supply routes from started machine units to the non-started machine units according to the mathematic models; calculating capacities and schedulable loads of the started machine units by using an optimal trend algorithm; and starting the non-started machine units in sequence according to the starting sequence, the power supply routes, and the capacities and the schedulable loads of a generator unit. Correspondingly, the invention further provides a system for the rapid self-healing of the power grid. According to the method and the system, the rapid self-healing of the power grid is realized by considering a plurality of machine units with black-start functions, and the steady trend constraint and the machine unit operation constraint are met.

The invention discloses a black-start method, which realizes the improvement of the rapid recovery of a grid and ensures system stability and equipment safety during the black-start process. The invention is achieved by the following technical proposal: in the black-start method, first, taking a large-capacity thermal power generating unit as black-start power supply to impact a large-capacity transformer with the power supply capacity less than that of the black-start power; then gradually restoring the significant load power supply, controlling the current to impact the load transformer towards a lower voltage level progressively, and carrying out power supply to the next electricity grid by the load transformer; and then gradually restoring the power supply to the partition power grid and the district power plants, and transferring electric current to other thermal power generating units with the same voltage level so as to provide electricity necessary for the operation of the corresponding thermal power plant, restore the electricity generation of the corresponding thermal power plant, control the electric current supplied by the power plant with the electricity restored, and impact other load transformers matched with the short-circuit capacity of the power supply system in the electricity networks; and finally gradually restoring the load power supply of the whole electricity grid.

A method for black starting a wind turbine and a wind farm following islanding operation, a method for restoring the wind farm following the islanding operation, and the wind turbine and wind farm. The wind turbine comprises auxiliary equipment, a generator, a converter electrically connectable to the generator, and an energy storage system, the generator is electrically connectable to the auxiliary equipment via the converter, the energy storage system is electrically connectable to the auxiliary equipment. The method for black staring the wind turbine including: measuring wind blowing smoothness degree; selecting a first power source to supply first power to the auxiliary equipment in V/f control mode and selecting a second power source to adjust an amount of active power and reactive power fed to the auxiliary equipment by the first power source in consideration of the amount of active power and reactive power demand suitable for powering the auxiliary equipment; and connecting the power sources to the auxiliary equipment.

The invention provides a wire frame reconstruction method and a wire frame reconstruction device of an electrical power system. The wire frame reconstruction method includes: on the basis of grid-connection of a black-start unit and a thermal power generating unit, recovering the electrical power system initially to form an initial wire frame reconstruction system; according to historical data of output power of a wind turbine generator, acquiring predicted data of real-time output power of the wind turbine generator at the moment corresponding to a wire frame reconstruction moment; on the bases of the predicted data of the real-time output power of the wind turbine generator and the initial wire frame reconstruction system, calculating the maximum value of circuit security risk conditions when load capability for recovering is maximal, and calculating the minimum value of the circuit security risk conditions when the load capability for recovering is minimal; according to the maximum value and the minimum value of the circuit security risk conditions and the initial wire frame reconstruction system, constructing a next-stage wire frame preconstruction model; on the basis of the wire frame preconstruction model, acquiring a reasonable preconstruction wire frame. The wire frame reconstruction method and the wire frame reconstruction device have the advantage that the wind turbine generator is enabled to participate in electrical power system recovering after blackout accidents.

The invention discloses a black-start system and method for a wind and light power storage station. The black-start system comprises an energy storage power station, a controllable load, corresponding boosting circuits, an alternating-current power transmission circuit and a supply and demand balance management system, the energy storage power station comprises an energy storage battery and one or a plurality of energy storage current transformers and is connected with the alternating-current power transmission circuit by the boosting circuits, a plurality of energy storage current transformers are parallelly connected to form the energy storage power station, and the energy storage power station establishes alternating-current voltage of the power transmission circuit and frequency when serving as a black-start power supply of the system; the boosting circuits comprise boosting transformers and circuit inductors, and low-voltage alternating current outputted by the energy storage current transformers is boosted to a voltage grade meeting the requirements of the power transmission circuit by the boosting circuits; the controllable load serves as a control unit for balancing power in the system, energy can bi-directionally flow, and the controllable load is an energy storage system dispatching the power; the supply and demand balance management system is a coordination control pivot of the whole wind and light power storage station in the black-start process and monitors states of power transmission lines, sources, loads, stored energy and power grids in real time.

The invention relates to a distributed micro-grid black-start control system and method based on photovoltaic and energy storage. At present, a distributed micro-grid black-start control system and method based on photovoltaic and energy storage, which are reasonable in structural design, do not exist. The black-start control system is characterized in that a photovoltaic array interface, a photovoltaic DC converter, a photovoltaic grid connected controller and an AC bus are connected in sequence through a cable, the photovoltaic DC converter, an energy storage charging controller and a storage battery are connected in sequence through a cable, and an energy storage current transformer controller and a storage battery DC controller are connected through a communication cable. The black-start control method is characterized in that A, an AC bus system provides power; B, a DC bus system provides power; and C, black-start of a distributed power supply is performed. The control system is reasonable in structural design, black-start of a distributed power supply can be achieved, the power failure area, the power failure time and the recovery time once a power grid breaks down can be reduced, and the safety stability of regional power grids and a large power grid can be improved.

A power compensator for an electric power transmission line. The power compensator includes a voltage source converter, a capacitor and an energy storage device. The energy storage device includes a high voltage battery having a short circuit failure mode, a first main switch and second main switch for disconnecting the battery from the capacitor, and a control unit for operating the first and second switch.

The invention discloses a handling method of province-level power grid black-start and large-area power failure accidents. The black-start of the power grid is divided into two stages, schemes of black-start of several subsystems are generated on conditions that black-start power sources and other constraint conditions are satisfied, and all of the schemes of black-start of the several subsystems are relatively independent and synchronous recovery is possible. When all of the subsystems are recovered, power is transmitted to surplus non-transmitted nodal points of designated girds, and power supply points are charged nodal points in the system at the moment, power-transmission paths are preferably calculated and are not necessarily black-start assembling units. The handling method of the province-level power grid black-start and large-range power failure accidents takes quick recovery optimization algorithms of large-area power failure accidents as the core, provides black-start optimization schemes by utilizing black-start optimization algorithms, divides the province-level power grid black-start into a stage of subsystem independent recovery and a stage of interconnection and corporation recovery to ensures that establishment of black-start schemes is more systemic and scientific.

A hybrid offshore wind field DC converter comprises the components of a diode rectifier, wherein the AC side of the diode rectifier is connected with a wind field internal network, and the DC side isconnected with high-voltage DC current; and an auxiliary converter which is connected with the wind field internal network and the high-voltage DC current, wherein the auxiliary converter comprises amodular multilevel converter of which the AC side is connected with the wind field internal network through a transformer; a sub-module string, wherein one end of the sub-module string is connected with the modular multilevel converter, and the other end is connected with a high-voltage DC power transmission line; and a filtering circuit, wherein the other end of the sub-module string is connectedwith the high-voltage DC power transmission line through the filtering circuit. Compared with a whole-voltage-grade MMC converter, the hybrid offshore wind field DC converter has the following beneficial effects: greatly reducing the number of submodules and IGBTs, reducing system cost, actively establishing wind field internal network voltage in a wind field starting period, supplying wind fieldstarting power and realizing black-start of the wind field.