1751results about "Ac-dc network circuit arrangements" patented technology

The invention relates to the technical field of voltage control, in particular to a time-delay-containing uncertain AC / DC micro-grid DC bus voltage control method, which comprises the following steps: acquiring load change and DC bus voltage fluctuation data, calculating a load current change rate, analyzing the correlation between voltage fluctuation and load change, and performing voltage adjustment. And time delay characteristics in a load state are identified, voltage fluctuation uncertainty factors are identified, and the time delay compensation amount is adjusted to restore the voltage stability. According to the invention, by adopting linear and nonlinear time-delay compensation strategies, the problem of accuracy of time-delay compensation under different load conditions is effectively solved, various load fluctuations and voltage changes can be dynamically adapted, the problem of uncertainty of voltage fluctuations is solved, and the prediction of voltage fluctuations is optimized by dynamically adjusting the weight of uncertainty factors. The over-reaction to sudden voltage change is reduced, the voltage stability is improved, and the operation stability and the voltage regulation precision of the micro-grid are remarkably improved.

The invention provides an urban rail transit energy management system considering new energy and energy storage access. The urban rail transit energy management system comprises a new energy power generation unit, an energy storage unit, a regenerative braking energy recovery unit and an energy management control platform, the new energy power generation unit and the energy storage unit are connected to a rail transit power supply system; the energy management control platform is connected with the power supply network and controls the units in a communication mode, energy flow in the rail transit power supply system is monitored, analyzed, optimized and dispatched so as to coordinate utilization of new energy power generation power, energy storage charging and discharging and regenerative braking energy, the energy utilization efficiency is improved, and the requirement for power grid outsourcing electric energy is lowered. The peak load of the system and the power grid electricity purchasing cost are effectively reduced, meanwhile, the overall energy utilization efficiency is improved, and energy conservation and consumption reduction are achieved while safe and stable operation of the rail transit system is ensured.

The invention relates to the technical field of hydrogen production, in particular to a quick response system of a double-probe hydrogen leakage explosion detector and a grading early warning method. Comprising a first hydrogen concentration detection probe and a second hydrogen concentration detection probe which are respectively arranged at two different positions of a monitored area to form a space complementation detection network; the signal processing unit is electrically connected with the two probes and is used for receiving and processing the concentration signals output by the probes; the quick response control module is used for calculating the hydrogen concentration change rate in real time based on an output result of the signal processing unit; the grading early warning module is used for generating different grades of early warning signals according to the hydrogen concentration change rate and the absolute concentration value; the communication interface module is used for transmitting the early warning signal to a remote monitoring terminal; the multi-physical-field parameter change of the electrolyte can be sensed in real time, the control instruction is dynamically corrected, and the anti-interference capability is high.

The invention provides a heat supply device of a photoelectric heating all-in-one machine, and belongs to the technical field of heat supply control. According to the device, the maximum power generation power of a photovoltaic panel is automatically tracked through the photovoltaic adaptation module, the photovoltaic power supply heating module is directly driven, the photovoltaic power supply heating module is always kept near the maximum power point, and the photovoltaic power generation heat transfer efficiency is improved; through feedback of the temperature transmitting module, the intelligent control module controls the photovoltaic adaptation module and the mains supply control module at the same time, photovoltaic direct drive and mains supply can be automatically matched to assist in automatic conversion of heating control for complementary heat supply, the intelligent control module has a temperature compensation control technology, and when the photovoltaic heat supply temperature is lower than the lower limit, the intelligent control module controls the intelligent control module to supply heat. Mains supply is automatically switched on for temperature compensation; meanwhile, the photovoltaic adaptation module and the photovoltaic power supply heating module are independent systems, the commercial power control module and the commercial power supply heating module are independent systems, and the two systems are independent of each other, have no interference to a power grid and are more stable and safer in operation. The intelligent heat supply mode switching method and device can improve the intelligence of heat supply mode switching.

A simulation system of a railway system for a Medium-Voltage Direct Current (MVDC) distribution network includes: a computing device which stores a simulation program including a converter station model configured to simulate a converter station included in the MVDC distribution network and a train operation model configured to simulate an operation state of a train that is supplied with power from the converter station and runs; a converter controller which controls a DC / DC converter included in the converter station model; and a Hardware In the Loop Simulation (HILS) device which performs a simulation based on the converter station model, the train operation model, and the converter controller. Herein, the converter station model and the train operation model are executed in software by the HILS device, and the converter controller is connected to the HILS device and driven to control the converter station model.

The invention relates to the technical field of power grid dispatching, and discloses an optical storage direct-current flexible micro-grid multi-target optimization dispatching system, which comprises a photovoltaic power generation module, an energy storage module, a direct-current power supply module, a flexible power supply module and a multi-target optimization dispatching module, and is characterized in that the multi-target optimization dispatching module comprises a monitoring unit used for monitoring each load unit in real time, acquiring basic power utilization information; the prediction unit is used for carrying out load prediction on the load unit at each moment every day according to the power utilization basic information; and the optimal scheduling unit is used for establishing a multi-target model by adopting a multi-target optimization algorithm and by taking the lowest daily operation cost and the maximum photovoltaic consumption rate of the optical storage direct-flexible micro-grid as targets, and solving the multi-target model based on a load prediction result to obtain an energy scheduling scheme of the optical storage direct-flexible micro-grid. According to the invention, the operation state of the micro-grid can be predicted and scheduled more accurately, so that an energy scheduling scheme with a better effect is obtained, and the energy utilization efficiency and the system operation stability are improved.

The invention relates to the technical field of micro-grid control, and discloses an AC / DC micro-grid layered distributed control method and system, and the method comprises the steps: obtaining a DC voltage outputted by a distributed power supply in a DC micro-grid and an AC frequency outputted by a distributed power supply in an AC micro-grid, and carrying out the normalization processing; according to the voltage normalization value and the frequency normalization value, a finite time consistency algorithm is adopted to calculate a primary active power reference value of the interconnected converter; compensating the primary active power reference value according to a distributed secondary controller to obtain a secondary active power reference value; and generating a control signal of each interconnected converter according to the secondary active power reference value. Through hierarchical distributed control, the purposes that the total power sent by the direct current micro-grid and the alternating current micro-grid is proportionally distributed according to respective rated capacities and the active power transmitted by all the interconnected converters is proportionally distributed according to the transmission capacities are achieved, and the operation safety and stability of the alternating current and direct current micro-grid are effectively improved.

The invention relates to a multi-source system comprising an electric machine (M), of the type comprising a rotor and a stator (1), the stator (1) comprising a plurality of windings (10, 11, 12) made of turns of insulated conductive material, each winding (10, 11, 12) comprising a plurality of independently powered coils (100, 101, 102), characterised in that the system also comprises a plurality of DC power sources and a plurality of power electronics converters associated with different coils (100, 101, 102) of the electric machine (M), each power source powering one or more power electronics converters and each power source being connected to at least one coil (100, 101, 102) of each winding (10, 11, 12) of the electric machine (M).

The invention discloses a bidirectional self-adaptive inertia control method and device for an interconnected converter, and the method comprises a voltage source converter structure, a bidirectional inertia control method and self-adaptive inertia coefficient set.The bidirectional self-adaptive inertia control method and device are suitable for an AC-DC hybrid micro-grid so as to balance AC micro-grid frequency and DC micro-grid voltage dynamic response. Virtual synchronous motor control is adopted as a control outer ring to realize power adjustment and emergency control mode switching, an additional virtual capacitor control ring is designed to suppress the influence of high-frequency interference on a differential element, and the method can enable an IC to adjust a working mode to operate in a rectification or inversion state under a self-adaptive operation condition, so that the reliability of the IC is improved. The strategy enables the interconnection converter to smoothly adapt to three operation modes of grid connection, island power adjustment and island emergency control, thereby balancing the dynamic response characteristics of the two modes after disturbance, and achieving the improvement of the overall performance of the AC / DC micro-grid.

The invention relates to a light storage integrated system and a control method, the system comprises a direct current bus, a photovoltaic access unit, an energy storage unit, a power conversion system and an energy management system, the energy storage unit and the photovoltaic access unit are accessed to the direct current bus, and the energy storage unit is provided with a plurality of SOC parameters including a lower discharge limit SOCmin, an upper charge limit SOCmax and an off-grid recovery threshold SOCon; the energy management system configures an energy management strategy in each mode through a plurality of SOC parameters set by an energy storage unit, realizes intelligent control and mode switching in a grid-connected mode and an off-grid mode, and in the grid-connected mode, preferentially utilizes photovoltaic power to supply power to a load, switches to an anti-countercurrent mode after the stored energy is fully charged, and dynamically limits the photovoltaic power to avoid countercurrent; in the off-grid mode, the power conversion system is controlled to operate in a VF mode, and photovoltaic power reduction is triggered when set conditions are met. Compared with the prior art, the method has the advantages that the countercurrent suppression efficiency is improved, and the system safety, reliability and stability are enhanced.

A power tool is provided including a power supply interface receiving a removable battery pack, a brushless direct current (BLDC) motor including a rotor and a stator, and a multi-phase inverter bridge circuit. A controller is provided to output drive signals to the inverter bridge circuit to control flow of current from to the motor, where each drive signal is activated within each corresponding phase of the motor within a conduction band. The controller is configured to control a length of the conduction band at a variable value within a first torque range below a torque threshold and at a substantially constant value within a second torque range above the torque threshold. The torque threshold is greater than approximately 1 Newton-meters and the motor produces a maximum power output of at least approximately 1250 watts at the torque of approximately 1 Newton-meters.

A method of determining the capability of a nonlinear aircraft power source includes accessing status values representing a current state of an energy storage system in an aircraft, accessing demand values related to expected power demands on the energy storage system, modeling an ongoing status of the energy storage system using the status values and the demand values to predict when one of the status values will reach a threshold value, and providing an output of a capability of the aircraft based on the status value reaching the threshold value.

The present disclosure relates to circuits for connecting components of a hydrogen plant to a power grid to power the components in an efficient manner. In one implementation, power-side alternate current (AC) to direct current (DC) converters may be connected to a source power grid without the need for an isolation transformer by providing separate buses between the power-side AC-DC converters and load-side DC-DC converters instead of a shared DC bus between the converters. Other implementations for connecting components of a hydrogen plant to a power grid may include an adjustable transformer, such as a tappable transformer or an autotransformer, to connect any number of auxiliary loads of the plant to the power grid. The adjustable transformer may provide for various types of auxiliary load devices to connect to the power provided by the transformer at the same time, including both three-phase devices and one-phase devices.

The present disclosure relates to circuits for connecting components of a hydrogen plant to a power grid to power the components in an efficient manner. In one implementation, power-side alternate current (AC) to direct current (DC) converters may be connected to a source power grid without the need for an isolation transformer by providing separate buses between the power-side AC-DC converters and load-side DC-DC converters instead of a shared DC bus between the converters. Other implementations for connecting components of a hydrogen plant to a power grid may include an adjustable transformer, such as a tappable transformer or an autotransformer, to connect any number of auxiliary loads of the plant to the power grid. The adjustable transformer may provide for various types of auxiliary load devices to connect to the power provided by the transformer at the same time, including both three-phase devices and one-phase devices.

An power system for a power system. The power system includes multiple electrical power sources and an enclosure operatively connected to the power sources at multiple input terminals. Multiple loads operatively connect to the enclosure at multiple output terminals by multiple cables. The enclosure includes the input terminals and the output terminals and a controller unit. Multiple selection units operatively connect to the controller unit, multiple power converters are connected to multiple connection paths. The selection units connect to at least one of multiple switches connected in the connection paths. Multiple sensor units are operatively attached to the controller unit which is configured to sence multiple parameters in the connection paths. Responsive to the parameters sensed by the sensor units, the selection units select the connection paths between the electrical power sources and the loads.

A marine AC generator system includes a marine generator driven by an internal combustion engine and configured to generate an AC current and a rectifier configured to rectify the AC current to provide a DC current. At least one battery is configured to receive and be charged by the DC current. A battery powered inverter is configured to be powered by the at least one battery and to generate a variable current output frequency such that an AC electrical power is provided to a load when the marine generator is not running.

The utility model relates to a power supply control device, power supply equipment and a logistics distribution system, and belongs to the technical field of power supply control. The device comprises a main controller; a plurality of slave controllers, wherein the first ends of the slave controllers are electrically connected with the master controller; the power supply devices are electrically connected with the second ends of the corresponding slave controllers; wherein when the master controller outputs a control signal for operating the first power supply device to the first slave controller, the first slave controller responds to the control signal and controls the first power supply device to work; wherein the first slave controller is one of the plurality of slave controllers, the first power supply device is one of the plurality of power supply devices, and the first power supply device corresponds to the first slave controller.

The invention discloses a power electronic hybrid distribution transformer and a control method thereof. According to the method, the power electronic hybrid distribution transformer comprises a traditional distribution transformer, a parallel converter, a direct-current bus and a series converter, the alternating-current side of the parallel converter is connected to the low-voltage side of the traditional distribution transformer in parallel, and the direct-current side of the parallel converter is connected with the direct-current bus; the AC side of the series converter is connected in series with the low-voltage side of the traditional distribution transformer, and the DC side is connected with the DC bus.

Disclosed is a power-limited network protection system designed to enhance the reliability and stability of networks with multiple remote nodes. This system employs a combination of power supplies and communication transceivers to modulate energy and data transmission, ensuring efficient operation across extensive distances. Each remote node is equipped with an advanced protection device featuring a controllable disconnect switch and monitoring capabilities for current and voltage. This configuration enables independent operation of nodes while preventing cascading failures. By dynamically managing power distribution and implementing fail-safe mechanisms, the system mitigates risks associated with overloads and shorts, ultimately enhancing network resilience. This invention is particularly beneficial in environments prone to electrical disruptions, ensuring continued functionality and minimizing operational downtime.

The invention discloses a dynamic load adjustment-liquid nitrogen cold storage integrated high-temperature superconducting power grid capacity expansion system and method. The system comprises a data preprocessing system, a dynamic load adjustment device, a liquid nitrogen cold storage device, a state monitoring device, a high-temperature superconducting cable capacity expansion device and a communication coordination system. The method comprises the steps of generating a standardized feature matrix through normalization processing; multi-time-scale load prediction is realized through an LSTM (Long Short-Term Memory) network, a collaborative instruction set is generated by adopting an optimal scheduling engine of mixed integer linear programming, and adaptive closed-loop control based on a fuzzy PID (Proportion Integration Differentiation) algorithm is realized; a multi-physics field coupling optimization model of a real-time cold energy distribution diagram is adopted to realize power grid capacity improvement; and the time sequence consistency of the whole system is coordinated and circulation is formed. Zero-resistance power transmission is realized in a liquid nitrogen temperature region by adopting the high-temperature superconducting cable, the loss is reduced to 0.5% or below, and the transmission capacity is improved by 3-5 times; the load demand is predicted in combination with the AI algorithm, and the renewable energy consumption rate is increased to 95%.

The invention discloses an electric appliance and a control method thereof, a power supply access module is connected with one of a first power supply and a second power supply to supply power to the electric appliance, and enters a power supply type detection mode when the electric appliance is electrified and started, a first processing device is connected to one of the first power supply and the second power supply, and a second processing device is connected to the other of the first power supply and the second power supply. The second processing device is connected to the electric appliance, the first processing device and the second processing device are communicated according to the first communication protocol, and the second processing device can judge the type of an external power supply currently connected to the electric appliance according to a communication result; on the basis, the type of the external power supply connected to the electric appliance can be automatically identified, so that when the external power supply changes, the electric appliance can timely identify change information of the type of the external power supply, and then the electric appliance can timely adjust a control strategy to adapt to different types of external power supplies, so that the electric appliance is prevented from being damaged, and the safety of the electric appliance is improved. And the use safety and the service life of the electric appliance can be improved.

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 a hybrid micro-grid group power coordination control method and device. The method comprises the following steps: establishing a hybrid micro-grid group topological structure; each alternating-current sub-network collects the bus frequency of the corresponding alternating-current bus, and each direct-current sub-network collects the bus voltage of the corresponding direct-current bus; when the bus frequency of the alternating current subnet or the bus voltage of the direct current subnet fluctuates in a first preset range, the alternating current subnet and the direct current subnet adopt adaptive droop control to realize power coordination; when the bus frequency of the alternating-current subnet or the bus voltage of the direct-current subnet fluctuates within a second preset range, the alternating-current subnet and the direct-current subnet achieve power coordination through power exchange; and when the bus frequency of the AC subnet or the bus voltage fluctuation of the DC subnet exceeds a second preset range, controlling the power output of the energy storage subnet to realize power coordination, and the method can improve the robustness of the system.

The application discloses a detection circuit used for short circuit detection of a power supply output port, comprising a short circuit detection circuit used for short circuit detection, a first port of the short circuit detection circuit is connected in series with a first auxiliary power supply circuit, a second port of the short circuit detection circuit is connected in parallel with the power supply output port, and a detection signal output by the short circuit detection circuit is input to a processor; the processor controls the power supply output port and the power supply to be in an isolated state in response to the power supply starting operation, and the detection current from the first auxiliary power supply circuit flows into the first end of the first port. Detection current flowing into the first end flows back to the first auxiliary power supply circuit through the second port, currently in the short circuit state, of the short circuit detection circuit and the second end in the first port of the short circuit detection circuit in sequence, so that the short circuit detection circuit outputs a first level signal used for representing existence of short circuit. According to the invention, short-circuit detection consumes less time, rapid residual voltage discharge can be realized, and damage to a power supply and internal components of a load is avoided.

An electrolyser plant (1A) is described. The electrolyser plant (1A) includes a first DC link (8) with at least one DC link capacitor (C1) and an AC / DC power converter (6). An electrolyser (10) is electrically connected to the first DC link (8) and adapted to receive a load current. During normal operation of the AC power network (2), a controller (12) is adapted to maintain a pre-event DC link voltage and supply a pre-event load current to the electrolyser (10). In response to a detected low voltage event, the controller (12) is adapted to: (a) initially supply the pre-event load current to the electrolyser (10) to maintain normal operation of the electrolyser (10), (b) monitor the DC link voltage, e.g., the voltage in the first DC link (8), and (c) if the monitored DC link voltage falls below a first voltage threshold that is less than the pre-event DC link voltage, reduce the load current supplied to the electrolyser (10), optionally by ramping down the load current at a suitable ramp rate.

The invention discloses an energy equipment control method and system based on a multi-terminal energy router and a medium, and relates to the field of expressways, and the method comprises the steps: collecting the real-time operation data, monitored by the multi-terminal energy router, of multi-terminal energy equipment along the expressway; based on the real-time operation data, constructing an energy network model of multi-terminal energy equipment along the highway; based on the energy network model, analyzing a supply-demand relationship of multi-terminal energy equipment along the highway, and determining an energy scheduling scheme; and based on the energy scheduling scheme, the multi-terminal energy equipment is scheduled through the multi-terminal energy router, and the energy scheduling scheme is dynamically adjusted according to the real-time monitoring result so as to optimize the transmission path and the flow direction of the energy in different scenes. The method can adapt to the dynamic change of the energy demand along the expressway, achieves the optimal scheduling and effective management of the multi-terminal energy equipment, and improves the energy utilization rate.

The invention discloses a single-stage interconnection converter port power distribution method based on a multilayer space vector modulation strategy. The method comprises the following steps: firstly, obtaining a single-stage interconnection converter alternating current side reference voltage vector through an energy management strategy, a power control loop and a current and voltage double closed loop of a hybrid alternating current and direct current micro-grid; then, the single-stage interconnection converter is subjected to equivalent decoupling modeling to form four virtual two-level converters, a four-layer space vector diagram is obtained, scaling factors for decomposing reference voltage vectors are calculated according to given reference power, and therefore the two reference voltage vectors on the alternating current side are decomposed into four independent voltage vectors; and synthesizing the four voltage vectors in a four-layer space vector diagram to obtain the duty ratio of each phase of the four two-level converters so as to obtain the switching sequence of the single-stage interconnection converter.

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.

The invention relates to the technical field of power grid equipment, in particular to a lightweight electric shunt with a temperature monitoring function and a monitoring system. The lightweight electric shunt with the temperature monitoring function comprises a temperature monitoring system, and the temperature monitoring system comprises a temperature detection module used for detecting real-time temperature information of the electric shunt in real time; the control module is used for collecting real-time temperature information and forwarding the real-time temperature information; meanwhile, whether the real-time temperature in the real-time temperature information is larger than a preset temperature threshold value or not is analyzed, and when the real-time temperature in the real-time temperature information is larger than the preset temperature threshold value, early warning information that the real-time temperature is larger than the preset temperature threshold value is output; the wireless communication module is connected with the control module and used for receiving the real-time temperature information and sending the real-time temperature information to a remote monitoring system; and meanwhile, the early warning information that the real-time temperature is greater than the preset temperature threshold is received and the alarm signal is output to trigger the alarm, so that the safety of the power grid equipment is improved.

The invention discloses an intelligent power distribution system and an application method thereof, and belongs to the technical field of power distribution networks. The system comprises a power distribution network, a multi-port SOP, a DC / DC converter, a photovoltaic power generation module and an energy storage module, the power distribution network is connected to the energy storage module through the multi-port SOP and the DC / DC converter in sequence, and the photovoltaic power generation module is also connected with the energy storage module through the DC / DC converter. And the multi-port SOP comprises a plurality of converters, AC ends of the plurality of converters are correspondingly connected with a plurality of nodes of the power distribution network, the plurality of converters share one DC end, and the DC end is connected to the energy storage module through a DC / DC converter. According to the invention, photovoltaic power generation and energy storage modules are combined with the SOP and are deployed in the power distribution network, and the utilization rate of renewable energy sources is improved by optimizing power transmission; meanwhile, a corresponding application method is provided, and normal operation optimization and fault recovery of the power distribution network are achieved.