382results about "Single ac network with different frequencies" patented technology

A method and device for supporting weak networks in an AC / DC distribution network are provided. The method includes the following steps: constructing a topology of the AC / DC distribution network, where the topology is configured to support the weak networks and isolate faults actively, and the topology is a multi-terminal ring structure; establishing a distributed optimization method for the AC / DC distribution network based on the topology; obtaining power fluctuations of the AC / DC distribution network, where the AC / DC distribution network can switch a droop control mode automatically according to the power fluctuations; and obtaining frequency fluctuations of the AC / DC distribution network, where the AC / DC distribution network performs energy dispatching according to the frequency fluctuations to match the droop control mode of the AC / DC distribution network.

The invention discloses a data center power supply system, and belongs to the technical field of power electronics. The power supply system comprises a plurality of multi-port solid-state transformers, each multi-port solid-state transformer comprises an input end, a first output end and a second output end, and the input ends are electrically connected with a medium-voltage power grid; the multi-port solid-state transformer is used for converting medium-voltage alternating current input by the input end into direct current with a first voltage value and direct current with a second voltage value; the multiple multi-port solid-state transformers supply power to multiple direct-current loads of the data center, the first output ends of the multi-port solid-state transformers are electrically connected with the corresponding direct-current loads, and the working voltage of the direct-current loads corresponds to the first voltage value; and the first inversion module is electrically connected with the second output ends of the plurality of multi-port solid-state transformers and is used for inverting the direct current with the second voltage value output by the second output ends and then supplying power to the alternating current load of the data center.

An integrated electrical management system includes an electrical panel, at least one busbar mounted to the electrical panel, at least one controllable breaker electrically coupled to the at least one busbar, and processing equipment configured to process electrical signals. The processing equipment includes control circuitry configured to control the at least one controllable breaker, and one or more current sensing modules configured to sense a respective current for each of the at least one controllable breakers. The system senses currents or otherwise electrical load in branch circuit, and is configured to control the breakers on or off to control electrical load in each branch circuit. The system may receive user input, input from devices, input from other systems or network entities, or inputs from sensors, and in response determines operating parameters. Operating parameters may include on-off schedules for breakers, temporal information, fault information, or other suitable operating parameters.

The invention relates to the technical field of micro-grids, in particular to an alternating current and direct current hybrid micro-grid cooperative control method. According to the technical scheme, the alternating current and direct current hybrid micro-grid cooperative control method comprises the following steps that S1, a multi-stage micro-grid framework is constructed and comprises a main micro-grid, a direct current sub-micro-grid and an alternating current sub-micro-grid, and the main micro-grid and the direct current sub-micro-grid are connected through a bidirectional interconnection converter; s2, deploying a hierarchical Multi-Agent control architecture, wherein the hierarchical Multi-Agent control architecture comprises a main micro-grid agent, a direct current sub-micro-grid agent and an alternating current sub-micro-grid agent; and S3, executing three-level cooperative control, receiving a main network scheduling instruction by the main micro-grid agent, decomposing the main network scheduling instruction into sub-micro-grid control targets, coordinating power distribution among sub-micro-grids based on a global optimization algorithm, and maintaining voltage and frequency stability by the DC sub-micro-grid agent and the AC sub-micro-grid agent through a local control algorithm. According to the method, the power grid consumption efficiency and the operation stability in a high-proportion new energy access scene are remarkably improved.

The invention relates to the technical field of power grid operation, in particular to an optical storage alternating current and direct current hybrid micro-grid system and method. A data acquisition module is used for acquiring operation parameters of each working module; the parameter correction module is used for correcting the operation parameters by adopting the weather data to obtain corrected operation parameters; the aging model generation module is used for generating a line aging prediction model based on the corrected operation parameters and the line parameters; the aging grade generation module is used for generating a current line aging degree grade by adopting the corrected line aging prediction model; the inspection strategy matching module is used for matching a corresponding maintenance inspection strategy based on the line aging degree grade; and the aging grade correction module is used for correcting the aging degree grade of the line based on the line feature information obtained by routing inspection. Therefore, the intelligent level and the operation and maintenance efficiency of the optical storage alternating current and direct current hybrid micro-grid system can be improved, and the operation and maintenance cost is reduced.

A wireless power transmitter that transmits power to a wireless power receiver, the wireless power transmitter including a communication unit configured to communicate with the wireless power receiver; and a controller, wherein the communication unit receives a plurality of packets including a foreign object detection (FOD) status packet from the wireless power receiver, wherein the controller determines whether a foreign object is present in a charging area of the wireless power transmitter on the basis of the FOD status packet, wherein the communication unit transmits, to the wireless power receiver, a response signal indicating whether the foreign object is present in the charging area of the wireless power transmitter on the basis of a result of the determination, wherein the response signal is determined using a measured peak frequency of a power signal transmitted by the wireless power transmitter and a reference peak frequency included in the FOD status packet received from the wireless power receiver, and wherein the plurality of packets further include at least one of a signal strength packet, an end power transfer packet, a power control hold-off packet, a configuration packet, an identification packet for transmitting receiver identification information, an extended identification packet, a general request packet, a special request packet, a control error packet, a renegotiation packet, a 24-bit received power packet, an eight-bit received power packet, and a charging status packet.

The invention discloses a parameter control method for a bidirectional power conversion circuit with alternating current and direct current electric energy interchange, which relates to the technical field of circuit parameter control, and comprises the following steps: respectively carrying out electric energy conversion on an alternating current side and electric energy adjustment on a direct current side by adopting a topological structure in which a three-phase voltage source type converter and a direct current circuit bidirectional converter are connected in series; collecting parameters of the AC-DC bidirectional power converter in real time; switching among three working modes of rectification, inversion and shutdown is realized; the DC bus voltage is kept at a rated value when supply and demand in the DC subnet are balanced, and bidirectional flow of power is realized when supply and demand are unbalanced; performing coordinate transformation on the acquired voltage and current; and separating positive and negative sequence components of the voltage by using a second-order generalized integrator algorithm. By adopting a specific topological structure and utilizing the droop characteristic to realize working mode switching, the adaptability and the control precision of the bidirectional power converter in the alternating current and direct current hybrid micro-grid are improved.

The invention discloses an AC / DC power grid probability static voltage stability margin calculation method, and relates to the technical field of AC / DC power grid safety assessment. Based on historical data, an AC / DC power grid uncertain source load output probability model is constructed, and the uncertain source load output is used as input; and taking the probability static voltage stability margin of the alternating current-direct current power grid as output, and establishing a probability static voltage stability margin calculation model of the alternating current-direct current power grid. Through a small-scale model input-output sample, an agent model for calculating the probability static voltage stability margin of the AC / DC power grid is constructed. And based on the agent model and in combination with a Monte Carlo simulation method, obtaining a probability static voltage stability margin result of the AC-DC power grid, and quantitatively evaluating the probability static voltage stability of the AC-DC power grid. Probability static voltage safety analysis is achieved, and therefore safe and reliable operation of an alternating current and direct current power grid is guaranteed. By introducing the proxy model, the calculation efficiency of the probability static voltage stability margin of the AC / DC power grid is greatly improved.

The invention provides a direct-current capacitance determination method for a flexible interconnection device of a three-port intensive low-voltage power distribution network, the flexible interconnection device comprises three alternating-current ports and a direct-current port, each alternating-current port is connected with a power grid through an alternating-current feeder line, and the direct-current port comprises a plurality of direct-current capacitors; the method comprises the following steps: respectively determining active power and reactive power of three alternating-current feeder lines, and respectively determining current and modulation voltage of three alternating-current ports according to the active power and the reactive power of the three alternating-current feeder lines; according to the current and the modulation voltage of the three alternating current ports, determining a current instantaneous value of a direct current capacitor without a current direct current component in a fundamental wave period; determining the capacitance value of the direct current capacitor according to the capacitor voltage ripple limit value and the current instantaneous value of the direct current capacitor; the scene of multiple alternating current ports is considered, and the adjusting effect of the power flow is improved.

A electrical power system comprises: an electrical machine operable to output AC; a DC electrical network; a power electronics converter connected between the AC output of the electrical machine and the DC electrical network and including a plurality of transistors and associated diodes connected in parallel with the transistors; and a controller configured to control switching of the transistors of the converter so that, during normal operation of the electrical power system, the converter rectifies the AC output of the electrical machine to supply the DC electrical network with DC electrical power. The controller is further configured, responsive to a determination to the effect there is a fault in the DC electrical network, to control a voltage source, to inject a voltage to bias the diodes of the converter, and to control the switching of the transistors to control a level of current supplied to the faulted DC electrical network.

The invention discloses an AC / DC power distribution network structure selection method comprising the following steps: obtaining typical scene data and candidate grid structure information, the typical scene data comprising scene load, distributed energy node information and a typical daily power curve; establishing a flexibility adjustment capability demand index system, and forming a multi-dimensional demand vector; calculating a flexibility evaluation index of each grid structure in a typical scene, and forming a capability vector; carrying out maximum and minimum normalization processing on the demand vector and the capability vector; and calculating the cosine similarity of the normalized capability vector and the demand vector as a matching degree, and sorting and selecting an optimal grid structure based on the matching degree. According to the method, multiple dimensions such as economical efficiency, new energy consumption rate and electric energy quality can be comprehensively considered, a scientific and visual decision basis is provided for complex AC / DC power distribution network architecture type selection, so that the problem that multiple targets are difficult to consider in a traditional method is solved, and the planning accuracy and efficiency are remarkably improved.

A wireless power receiver that receives power from a wireless power transmitter, the wireless power receiver including a communication unit configured to communicate with the wireless power transmitter; and a main controller, wherein the main controller generates a plurality of packets including a foreign object detection (FOD) status packet, wherein the communication unit transmits the FOD status packet to the wireless power transmitter, and the communication unit receives, from the wireless power transmitter, a response signal indicating whether a foreign object is present in a charging area of the wireless power transmitter, wherein the response signal is determined using a measured peak frequency of a power signal transmitted by the wireless power transmitter and a reference peak frequency included in the FOD status packet received from the wireless power receiver, and wherein the plurality of packets further include at least one of a signal strength packet, an end power transfer packet, a power control hold-off packet, a configuration packet, an identification packet for transmitting receiver identification information, an extended identification packet, a general request packet, a special request packet, a control error packet, a renegotiation packet, a 24-bit received power packet, an eight-bit received power packet, and a charging status packet.

The invention relates to the technical field of power electronics, and discloses a wall-mounted power supply and an intelligent monitoring system thereof, and the system comprises a cabinet body which is internally divided into a top AC input region, a middle region and a bottom battery output region; according to the two-way alternating current input circuit, an alternating current input 1 and an alternating current input 2 are respectively connected to a contactor through a circuit breaker to realize switching of a main power supply and a standby power supply through interlocking logic; the rectification and conversion circuit is used for converting AC input into DC48V through a rectification module to charge the lithium iron phosphate battery pack, and outputting the DC 48V to a DC bus through a boost module; an output power distribution circuit, wherein the DC bus is distributed to a plurality of load output circuits through a fuse; and a monitoring unit interface. Seamless switching of two-way alternating current input is achieved through mechanical and electrical interlocking design, zero-delay switching power supply of a main power supply and a standby power supply is ensured, the state of a battery is monitored in real time, a charging and discharging strategy is dynamically optimized, multiple protection mechanisms are integrated, power supply continuity is remarkably improved, the service life of the battery is prolonged, and stable operation requirements under complex working conditions are met.

In an embodiment, a power delivery system includes a first current limiter and a second current limiter in parallel with each other, wherein a direct current (DC) voltage is provided to each of the first current limiter and the second current limiter; a first transformer electrically coupled to the first current limiter; a second transformer electrically coupled to the second current limiter; first differential signal traces electrically coupled to the first transformer; and second differential signal traces electrically coupled to the second transformer, wherein the DC voltage is transmitted from the first transformer to the first differential signal traces simultaneous with the DC voltage being transmitted to the second differential signal traces by the second transformer.

The present disclosure provides a method for detecting a foreign object placed in a charging area of a wireless power transmitter and a wireless power transmitter. The method includes transmitting, by the wireless power transmitter, a power signal having a predetermined strength; measuring, via a controller, a peak frequency of the power signal; receiving, from a wireless power receiver, a data packet including a mode bit field, the mode bit field indicating whether the data packet includes a reference peak frequency of the wireless power receiver, wherein the reference peak frequency is pre-assigned to the wireless power receiver; in response to the mode bit field indicating that the data packet includes the reference peak frequency, determining, via the controller, an adaptive threshold frequency adjusted based on the reference peak frequency; and determining, via the controller, whether a foreign object is present in the charging area based on a comparison of the measured peak frequency of the power signal and the determined threshold frequency.

An electrical distribution grid energy management and router device, or GER device, may be installed in a distribution grid, and route power from power supply to one or more power consumers. The GER devices described herein may provide platforms to add one or more features to a distribution transformer, provide additional features and benefits to both the utility company and end consumer, and may serve as a platform for providing other features, such as multi-layer protection systems for detecting, among other things, one or more fault conditions, and responding to such conditions when detected. A GER device may include sensors to measure electrical properties of incoming and outgoing power, and may include an electrical circuit layer having a central DC power stage.

The present invention belongs to the field of direct-current traction power supply systems. Disclosed is a control architecture for a flexible direct-current traction power supply system based on energy routers. The flexible direct-current traction power supply system comprises a plurality of traction substations, and external power sources connected to the plurality of traction substations, wherein locomotives are connected to the traction substations by means of a catenary system, each traction substation comprises a plurality of energy routers, and each energy router comprises at least three ports, a first port being connected to the external power source by means of a traction substation alternating-current bus, a second port being connected to the catenary system by means of a traction bus, and the other ports being connected to one or more of photovoltaics, wind power, energy storage, a direct-current load and an alternating-current load. The solution of the present invention overcomes the defects of existing direct-current traction power supply systems using a diode rectifier unit as a core power supply device and existing direct-current traction power supply systems based on energy routers in the aspect of system structure design, and provides a corresponding collaborative control technical solution.

A self-contained nanogrid system comprises a power supply input to couple to an external primary power source within a premises, a switch coupled to connect or disconnect the system from the primary power, and a battery as backup to the primary power source. The system further comprises a DC power bus coupled to the battery, an AC power bus coupled to the power supply input via the switch, and a bidirectional inverter coupled between the AC and DC power buses. The system further comprises an integrated load coupled to receive power from the AC power bus or the DC power bus, a power output to provide power from the AC power bus or the DC power bus to an external load, and a processing unit configured to control operations of the self-contained nanogrid system, including the switch.

The embodiment of the invention discloses a control system of a multi-voltage bus hybrid micro-grid. The control system comprises a control layer and a hardware layer, wherein the medium-voltage direct-current bus is used for being connected with a distributed energy module of which the power is higher than a first set power value; the low-voltage direct-current bus is used for connecting an equipment assembly of which the power is lower than a second set power value, and the equipment assembly at least comprises a direct-current load of which the power is lower than a set value and a data center load; the AC bus is compatible with a traditional power grid and an AC load; the main control layer is used for realizing closed-loop regulation of voltage and current; the auxiliary control layer realizes the consistency of multi-bus voltage and frequency based on state estimation, bus impedance identification and virtual inertia control; and the comprehensive power management layer realizes cross-bus energy balance and power sharing based on a model predictive control and optimal scheduling algorithm. The technical problems that in the prior art, a control layer and a hardware layer of the multi-voltage bus hybrid micro-grid are independent of each other, a cooperative relation is lacked, and the dynamic self-adaptive adjustment type is poor are solved.

A grid direct-current flexible loop closing control device is a series-parallel device and includes a series coupling unit, a parallel coupling unit, a bypass switch circuit, and a loop closing main controller. The series-parallel devices is connected in series between each distribution line and a load, and after a loop closing instruction is received, the loop closing control devices are set to work in a voltage control mode; after direct-current bus voltages of two loop closing control devices are identical, a system enters a loop closing state. Before exiting loop closing, the loop closing control devices are set to be in a PQ control mode, access switches are sequentially turned off after P and Q are gradually decreased to zero, and a loop closing process is ended. The device is simple in structure, low in cost and high in efficiency, and has fewer loop-closing monitoring quantities.

A method of transmitting power by a wireless power transmitter, the method including receiving a plurality of packets including a foreign object detection (FOD) status packet from a wireless power receiver; determining whether a foreign object is present in a charging area of the wireless power transmitter on the basis of the FOD status packet; and transmitting, to the wireless power receiver, a response signal indicating whether the foreign object is present in the charging area of the wireless power transmitter on the basis of a result of the determination, wherein the response signal is determined using a measured peak frequency of a power signal transmitted by the wireless power transmitter and a reference peak frequency included in the FOD status packet received from the wireless power receiver, wherein the plurality of packets further include at least one of a signal strength packet, an end power transfer packet, a power control hold-off packet, a control error packet, a renegotiation packet, an eight-bit received power packet, and a charging status packet, to which a byte encoding technique is applied, and wherein the byte encoding technique is a technique of inserting a start bit, a stop bit, and a parity bit into an encoded binary bit stream of a packet having a length of eight bits.

The present invention provides a flexible DC loop closing control device for a power grid and a control method thereof. The present invention discloses a flexible DC loop closing control device for a power grid and a control method thereof. The device is a series-parallel device including a series coupling unit, a parallel coupling unit, another bypass switch circuit, and a loop closing main controller. Each set of series-parallel devices is configured to be connected in series between the distribution line and the load of each section. After receiving a loop closing command, the loop closing control device is set to operate in a voltage control mode, and after the DC bus voltages of the two sets of loop closing devices are consistent, the system enters a loop closing state. Before the loop closing is terminated, the device is set to a PQ control mode, which gradually reduces P and Q to zero, sequentially turns off the introduction switches, and the loop closing flow is terminated. The device has the advantages of simple structure, low cost, less loop closing monitoring amount than AC loop closing, and high efficiency. It can achieve flexible power mutual support and rapid shutdown in the event of a fault, and not only can it optimally adjust the power factor of the supply area per loop-closed transformer, but it can also flexibly change the power supply method of the power distribution grid to improve the new energy consumption level and DC load acceptance capacity.

The differentiated flexible net rack planning method based on high and medium pressure coordination comprises the steps of judging whether a to-be-planned area is a city scene or a rural scene, if the to-be-planned area is the city scene, selecting a first net rack structure, and if the to-be-planned area is the rural scene, selecting a second net rack structure; constructing a plurality of alternative planning schemes based on the selected grid structure in combination with the planning requirements of the power distribution network; constructing a target function by taking the minimum annual comprehensive cost of power grid construction as a target; and screening out a scheme with the minimum annual comprehensive cost of power grid construction from the alternative planning schemes through the objective function. According to the design, a high and medium voltage power distribution network coordination strategy of an urban scene and a rural scene is defined, the flexible adjustment capability of the flexible grid structure is fully exerted, and efficient access of emerging flexible resources such as distributed new energy, energy storage equipment and electric vehicles can be adapted.

This invention relates to a method, apparatus, equipment, and medium for optimizing the operation of a flexible interconnected distribution network. The method includes: approximating the nonlinear power flow calculation equations of the AC portion of the AC / DC distribution network to construct a DC power flow model for the AC portion; approximating the nonlinear power flow calculation equations of the DC portion of the AC / DC distribution network to construct a DC power flow model for the DC portion; constructing an optimized operation model for the flexible interconnected distribution network, with the goal of minimizing network losses and using the DC power flow models of the AC and DC portions as constraints; solving the optimized operation model to obtain an optimized operation scheme for the flexible interconnected distribution network; and controlling the operation of the flexible interconnected distribution network using the optimized operation scheme. This invention avoids cone relaxation of large-scale nonlinear constraints, improving the efficiency of optimization calculations.

The disclosure provides an energy station system, a control method of the energy station and an energy station. The energy station system includes at least one input energy source, at least one load, at least one central control module, and a switchable energy module. The switchable energy module switches its own working state based on a supply-demand relationship between the input energy source and the load, and the central control module controls the input energy source to supply power to the load. Through arranging the switchable energy module, it may be used to switch its working state according to the supply-demand relationship between the input energy source and 10 the load, so as to supplement the supply and demand imbalance between the input energy source and the load as characteristics of the input energy source or a DC load.

A resilient on-site microgrid system includes a multiport power router directly connected to various energy sources, including batteries, renewable energy sources, and broader grid power, as well as various loads, including electric vehicle chargers. The multiport power router dynamically adjusts power provided from the various power sources and to the various loads, especially to power devices in a nearby facility. The microgrid system includes various bypass systems allowing for powering of critical loads in the event of failure of individual components or pathways within the microgrid system.

The invention discloses a true bipolar flexible low-frequency power transmission system. An existing flexible low-frequency power transmission system mainly adopts a three-phase power transmission structure which is the same as that of a power frequency power transmission system, and popularization of the flexible low-frequency power transmission system is restricted. The system comprises two frequency conversion stations, a low-frequency positive electrode line and a low-frequency negative electrode line, each frequency conversion station comprises an anode frequency converter and a cathode frequency converter; one side of the anode frequency converter is connected with a power frequency AC power grid through a three-phase transformer, and the other side is connected with a low-frequency transmission line through a single-phase three-winding transformer. One side of the cathode frequency converter is connected with the power frequency AC power grid through the three-phase transformer, and the other side is connected with the low-frequency transmission line through the single-phase three-winding transformer. The low-frequency positive electrode circuit and the low-frequency negative electrode circuit have the same voltage amplitude, the same frequency and a phase difference of 180 degrees. According to the invention, interconnection and mutual assistance among different three-phase alternating current systems are realized through a two-phase power transmission structure, a new system structure is expanded for low-frequency power transmission, and the line construction cost is reduced.

The invention discloses a deep sea underwater equipment alternating current power supply system and a simulation method based on Matlab / Simulink, and the method comprises the steps: carrying out the modeling of each important part of the deep sea underwater equipment alternating current power supply system, and building a whole power supply system simulation model according to the simulation parameters of the system; a mother ship power supply emits preset alternating current, and the voltage is boosted to a target voltage value through a boosting device; electric energy is transmitted through an umbilical cable, one path supplies power to the underwater high-voltage motor, and the other path is reduced to a preset voltage value through a step-down transformer; the alternating current with the preset voltage value is converted into direct current with the preset voltage value through rectification of a rectifier; by collecting simulation waveforms of key parts of a power generation side, a high-voltage side, a motor side and a direct-current low-voltage side in a power supply system, the running condition of the whole power supply system and the reasonability of the design of the power supply system are judged, parameters of power supply equipment are changed in real time, the parameters are optimized through the simulation waveforms, and simulation of the power supply system is completed.

A resilient power router system with simplified connection to various energy sources, including batteries, renewable energy sources, and broader grid power, as well as various loads, including data centers. The multiport power router dynamically adjusts power provided from the various power sources and to the various loads, especially to for medium voltage applications. The multiport design enables scalability to multi-megawatt (MW) and medium voltage levels.

The present disclosure provides a method and a wireless power receiver for communicating with a wireless power transmitter. The method comprises: receiving, by the wireless power receiver, a power signal having a predetermined strength from the wireless power transmitter; transmitting, by the wireless power receiver, a data packet comprising a mode bit field to the wireless power transmitter, the mode bit field indicating whether the data packet comprises a reference peak frequency of the wireless power receiver, wherein the reference peak frequency is pre-assigned to the wireless power receiver; and receiving, by the wireless power receiver, a response from the wireless power transmitter indicating a presence or absence of a foreign object in a charging area, wherein the response is determined based on a comparison of a peak frequency of a measured power signal and an adaptive threshold frequency adjusted based on the reference peak frequency.