113 results about "DC distribution system" patented technology

The invention discloses a direct-current arc fault diagnosis method and device with adaptive capacity. The method comprises the following steps: 1) collecting a current alternating-current component when a current direct-current system normally works; 2) extracting time-frequency domain characteristics of a current AC component, wherein the time-frequency domain characteristics comprise a current peak-to-peak value, a standard deviation and an amplitude reconstruction harmonic power sum; 3) performing multi-time-frequency-domain feature fusion based on mahalanobis distance to obtain arc detection features; 4) calculating an arc fault judgment threshold value based on a box plot method; 5) collecting a current AC component in real time to calculate a Mahalanobis distance, comparing the Mahalanobis distance with an arc fault determination threshold, and recording an arc event; the method has the advantages that the system adaptability is high, the detection rate is high, the false alarm rate is low, and the method can be widely applied to high-voltage and low-voltage direct-current power distribution systems such as airplanes, vehicles and ships.

Voltage command values are set according to voltage fluctuations of a plurality of power supply sources, and one of outputs from a plurality of power supply circuits which output DC voltages obtained by performing conversion according to the voltage command values is supplied to a power conversion circuit as control power so that the system can be continuously operated even at the time of an abnormality due to a device failure and a power outage, and control power consumption can be suppressed in the case of voltage fluctuations of the power supply sources.

The invention relates to the technical field of power electronics and power supply and distribution, and discloses a data center AC / DC power distribution system input and output voltage and current monitoring method, which comprises the following steps: deploying an intelligent sensing unit with edge computing capability at each monitoring node, sampling according to a basic frequency, and extracting effective values, harmonic distortion rates, differential change rates and other characteristics of voltage and current in real time; judging that the system is in a steady state, a quasi transient state or a strong transient state according to the multi-stage dynamic threshold value, and respectively executing feature abstract uploading, local high-frequency backtracking or collaborative full-waveform synchronous acquisition; and the central server classifies and stores the data, constructs a state evolution model, and dynamically optimizes threshold parameters. The system comprises an intelligent sensing unit, a central monitoring server and an industrial Ethernet link. According to the method, the steady-state data transmission quantity is remarkably reduced, transient details are completely captured, and adaptive adjustment of the monitoring sensitivity is realized.

The invention belongs to the technical field of ship power distribution, and particularly discloses a double-bus redundant direct-current power distribution system for a ship. Comprising a first direct-current busbar left, a first direct-current busbar right, a second direct-current busbar left, a second direct-current busbar right, a first circuit breaker, a second circuit breaker, a lithium battery pack, a first propulsion inverter cabinet, a first daily inverter cabinet, a second propulsion inverter cabinet, a second daily inverter cabinet, a direct-current voltage stabilizer and a system charging socket box. According to the invention, through setting the first direct-current busbar left, the first direct-current busbar right, the second direct-current busbar left, the second direct-current busbar right and the switching relation thereof, and adopting an operation mode that one group of busbars works and the other group of busbars is standby, flexible and balanced distribution of a power supply and a load is realized, and all loops can work without power failure; once any busbar or branch has a fault, the standby busbar is immediately started so as to start the standby loop, so that no power loss and no power reduction of the whole ship are ensured, and all equipment and components of the whole system are subjected to redundancy design so as to ensure that the power distribution system always supplies power normally.

The invention discloses a grid-connected detection method, device, medium and product for an AC / DC power distribution system, and the method comprises the steps: building a power flow model of the AC / DC power distribution system before grid connection of a distributed power supply, obtaining a time sequence power flow result according to the power flow model, carrying out the reliability calculation of the AC / DC power distribution system, and obtaining a reliability calculation index, and according to the time sequence power flow result and the reliability calculation index, constructing a comprehensive performance index of the AC / DC power distribution system, and according to the comprehensive performance index, generating operation state information of the AC / DC power distribution system for distributed power supply grid connection. According to the operation state information, weak links needing to be transformed of the AC / DC power distribution system can be determined, technical support and guidance can be provided for a distributed power supply grid connection strategy, and safe and reliable operation of the AC / DC power distribution system can be promoted. By optimizing scheduling and power supply planning, the operation efficiency of the AC / DC power distribution system can be improved, the operation cost can be reduced, and the accuracy of grid-connected detection of the AC / DC power distribution system can be improved.

The invention discloses an MMC pre-charging method based on bridge arm module alternate bypass. The method comprises the following steps: detecting the voltage of a grid-connected point at the AC side of an MMC; detecting a medium-voltage energy storage unit and a low-voltage energy storage unit, and selecting an energy storage unit participating in MMC pre-charging and a corresponding control mode according to a detection result; controlling a DC bus voltage in the DC power distribution system to be raised to a rated value of a capacitor voltage of an MMC bridge arm sub-module, and executing an MMC pre-charging mode; on the premise that the voltage fluctuation amplitude of the direct-current bus does not exceed the allowable range, different sub-modules on the same bridge arm of the MMC are bypassed alternately in sequence until the difference value between the capacitor voltage of the bridge arm sub-module and the rated working voltage of the bridge arm sub-module is within the allowable range; and closing a circuit breaker at the AC side of the MMC, unlocking the MMC, switching the pre-charging mode of the MMC to a normal operation mode, executing constant DC voltage control by the MMC, and recovering the determined control mode of the energy storage unit to a constant power control mode.

To provide a load control device that suppresses a voltage rise on a DC bus even if a plurality of loads simultaneously generate regenerative power.SOLUTION: A DC power distribution system includes a DC bus, a plurality of regenerative loads connected to the DC bus, a storage battery connected to the DC bus via a DC / DC converter, and a load control device that performs regeneration control of the loads. The load control device includes a storage unit that stores regenerative power data of the loads and a preset upper limit charge power when charging the storage battery, and a control unit that controls the regeneration start time of each of the plurality of loads so that the upper limit charge power is not exceeded during the regenerative operation of the plurality of loads.SELECTED DRAWING: Figure 1

The invention discloses an electric tug energy efficiency management method based on a large model, and the method comprises the following steps: S1, energy dynamic distribution optimization: carrying out the optimization of energy dynamic distribution based on the large model according to the real-time load of an electric tug; s2, charging strategy optimization: according to the price gradient of the power grid, the charging time and the charging electric quantity of the electric tug are optimized; s3, safety protection of the battery system: monitoring the temperature, voltage and current of the battery in real time, and performing early warning protection on the battery; s4, safety guarantee of the propulsion system: monitoring operation data of the propulsion system in real time, and performing protection, fault monitoring and fault diagnosis on the propulsion system; s5, safety redundancy of the power supply system: monitoring and adjusting the electric energy quality of the DC power distribution system, and supplying emergency power to the AC power distribution system; according to the method, accurate power distribution, intelligent charging management, efficient safety protection and reliable power supply guarantee are achieved, and the energy efficiency and operation safety of the electric tug are improved.

This invention discloses an active damping control method for bipolar DC distribution systems based on modulus decomposition. It incorporates line coupling into the system's stability criteria and active damping parameter design, deriving the pole-mode transformation matrix of the metal-return bipolar DC distribution system and obtaining a decoupling model of the bipolar DC line in the modulus component space. The modulus models of the source-side converter and load are also derived. Based on the established decoupling model of the bipolar DC distribution system in the modulus component space, an active damping control method based on modulus decomposition is proposed. This invention considers the impact of DC distribution lines on stability, incorporating line coupling into the system's stability criteria and active damping parameter design. The modulus damping control scheme proposed in this invention can more effectively suppress instability caused by the negative impedance characteristics of constant power loads and also provides a basis for parameter adjustment.

The invention relates to an AC / DC power distribution system networking method suitable for different typical scenes, and the method comprises the following steps: S1, constructing a networking mode based on a grid structure of a DC power distribution network; s2, constructing a networking mode based on the wiring mode of the DC power distribution network; s3, constructing a networking mode based on the grounding mode of the DC power distribution network; s4, constructing a networking mode based on an alternating current and direct current interconnection mode and a system primary and secondary equipment configuration principle; and S5, networking the typical application scenes of the AC / DC power distribution system suitable for the different typical scenes based on the networking modes of the typical application scenes of the AC / DC power distribution system suitable for the different typical scenes constructed in the steps S1 to S4. According to the invention, the networking mode suitable for typical application scenes of the AC / DC power distribution system in different typical scenes is constructed, different power grid structures and operation modes are adapted, and safe power supply is ensured.

The application provides a DC power distribution network source-load-storage self-adaptive power distribution method based on flexible droop control, aiming at coordinating the logical relationship between the maximum power constraint of new energy, the residual capacity constraint of energy storage equipment and the controllable range constraint of load and the voltage-power droop control in the DC power distribution network, meanwhile, the application determines a droop coefficient setting method in the form of power standard, provides a unified droop coefficient setting rule for equipment of different categories, capacities and rated powers, and ensures that each equipment can determine the quota participating in the self-adaptive power distribution according to the current working condition under the droop coefficient setting scheme, compared with the existing scheme, the self-adaptability of the power distribution among the source, the load and the storage in the DC power distribution system is improved.

An alternating current to direct current (AC to DC) power converter assembly that converts a plurality of low voltage alternating current (AC) inputs into a high voltage DC power output. The converter includes two or more AC to DC power converters, each of the two or more AC to DC power converters including: a low power AC power input configured to receive an AC input from a low power AC power source; and a low power DC power output. The converter also includes two or more isolated DC to DC power converters, each DC to DC power converter electrically coupled at least one of the AC to DC power converters, wherein each DC to DC power converter includes an output and wherein each of the DC to DC power converters are connected in series to produce the high power DC power output.

The disclosure provides a method of detecting arc faults in a DC power distribution system. The method comprises: sampling, using one or more sensors, a voltage signal on a conductor forming a current path of the power distribution system to generate a voltage signal sample vector; sampling, using the one or more sensors, a current signal in the conductor to generate a current signal sample vector; generating one or more feature vectors based on the voltage signal sample vector and the current signal sample vector and having fewer elements than the current signal sample vector or the voltage signal sample vector; providing the one or more feature vectors to an arc fault classification model; and receiving as an output of the arc fault classification model an indication of whether an arc fault is occurring in the power distribution system.

The application discloses a kind of grid-connected detection method, equipment, medium and product of AC-DC distribution system, the method includes: establishing the power flow model of AC-DC distribution system before distributed power grid connection, and according to power flow model obtains time series power flow result, the reliability calculation of AC-DC distribution system is carried out, obtains reliability calculation index, according to time series power flow result and reliability calculation index, the comprehensive performance index of AC-DC distribution system is constructed, according to comprehensive performance index, the operation state information of AC-DC distribution system is generated for distributed power grid connection.According to operation state information, the weak link that AC-DC distribution system needs to be reformed can be determined, and technical support and guidance can be provided for distributed power grid connection strategy, which is conducive to promoting the safe and reliable operation of AC-DC distribution system.Through optimization scheduling and power supply planning, the operation efficiency of AC-DC distribution system can be improved, the operation cost is reduced, and the accuracy of grid-connected detection of AC-DC distribution system is improved.

The embodiment of the invention provides a mining DC power distribution system. In one specific embodiment, the system comprises a rectification filtering unit, an energy storage assembly, a first power-off change-over switch, a second power-off change-over switch, relay power generation equipment and a controller. The controller is used for acquiring a first conversion state of the first power-off automatic conversion switch, responding to the first conversion state as an instruction that the output end of the first power-off automatic conversion switch is connected with the standby input end, controlling the power generation equipment to be started, acquiring an operation state of the power generation equipment, responding to the operation state as an operation ready instruction, and controlling the power generation equipment to be started. And the coil of the relay is controlled to be electrified. The mining DC power distribution system can stably and continuously supply power for a long time.

A DC power distribution system (100) includes a panel (1), a power source (3), and a connector (2). The panel (1) has a pair of planar conductors (11, 12) arranged at intervals in one direction, and a plurality of attachment parts (14) penetrating the pair of conductors (11, 12) in one direction. The power source (3) supplies DC power to the pair of conductors (11, 12). The connector (2) is provided to the load (4), has a pair of electrodes (23, 24), and can be attached to any one of the plurality of attachment sections (14). The connector (2) supplies DC power output by the power source (3) to the load (4) via the pair of electrodes (23, 24) and the pair of conductors (11, 12) in a state in which the connector (2) is attached to the attachment section (14).

The present application relates to the field of power electronics and power supply and distribution technology, and discloses a monitoring method for input and output voltage and current of an AC / DC power distribution system in a data center, which comprises: deploying intelligent sensing units with edge computing capabilities at each monitoring node to sample at a basic frequency and extract real-time characteristics such as effective value, harmonic distortion rate and differential change rate of voltage and current; determining whether the system is in a steady state, quasi-instantaneous state or strong instantaneous state according to multi-level dynamic threshold values, and performing feature abstract upload, local high-frequency backtracking or collaborative full-waveform synchronous acquisition respectively; storing data in a central server and constructing a state evolution model to dynamically optimize threshold parameters. The system comprises intelligent sensing units, a central monitoring server and an industrial Ethernet link. The present application significantly reduces steady-state data transmission volume, completely captures transient details and realizes adaptive adjustment of monitoring sensitivity.

The invention discloses a direct-current system ground fault detection method and system, and the method comprises the steps: respectively connecting resistors with equal resistance values between a positive bus and a negative bus of a direct-current system and the ground to form a symmetric resistance network, and collecting positive / negative voltage to ground and the grounding current of each branch in real time; extracting a high-frequency component through wavelet transform and energy entropy analysis to generate a frequency domain mark; performing wavelet transformation and energy entropy calculation on the grounding current signal, and extracting a high-frequency detail component; and a hierarchical collaborative decision is executed, immediate tripping is triggered by double marks, a delay recheck mechanism is started by single mark triggering, tripping is executed after continuous triggering, and a fault is positioned and reported. According to the technical system, the comprehensive identification speed of the grounding fault of the direct-current system is improved, full-process closed-loop protection of rapid sensing and identification, reliable decision making and accurate positioning is formed, and the operation safety of the direct-current power distribution system is improved.

The invention discloses a power diode fault detection method in a specific power distribution system, and relates to the technical field of aviation power distribution. The invention relates to a power diode fault detection method in a specific direct current power distribution system, which does not need to additionally add a test circuit and realizes diode fault detection by using an inherent sensor in a specific power distribution system network. The method is applied to a complex specific power distribution system, fault identification of the power diode is realized by detecting voltage and current at two ends of the power diode under a complex power distribution network topology, and the method is used for identifying a short-circuit fault and an open-circuit fault of the diode.

The present invention discloses a voltage balancing control method and system for a DAB output series voltage balancer. Aiming at the DAB output series voltage balancer topology, the present invention proposes a dual-loop voltage balancing control method, which is composed of a series voltage outer loop and a voltage balancing inner loop. Among them, the outer loop uses the fundamental wave shift ratio of triple phase shift control as the control quantity, which can effectively reduce the current stress of the DAB while achieving a given value for the output voltage of two DABs in series; the inner loop adjusts the fundamental wave shift ratio of the two DABs through an integrator and a voltage comparator, thereby achieving equal output voltages. Under the control method proposed by the present invention, the output voltage of the DAB output series voltage balancer can be well balanced, and has high application value in bipolar DC power distribution systems.

The application provides a Kun-type hybrid polarity direct current power distribution system and a four-transformer QAB converter h1 The positive pole of the high-voltage side bus is connected to the high-voltage side active bridge H l1 The positive pole of the low-voltage side bus is connected to the high-voltage side active bridge H h2 The negative pole of the high-voltage side bus is connected to the low-voltage side active bridge H l2 The negative pole of the low-voltage side bus is connected to the high-voltage side active bridge H h1 The high-voltage side active bridge H l1 is connected to the low-voltage side active bridge H r1 through a high-frequency transformer T h2 The high-voltage side active bridge H l2 is connected to the low-voltage side active bridge H r2 through a high-frequency transformer T l1 The low-voltage side active bridge H h2 and the high-voltage side active bridge H e1 are connected through a transformer T h1 The low-voltage side active bridge H l2 and the high-voltage side active bridge H e2 are connected through a transformer T The Kun-type hybrid polarity direct current power distribution system provided by the application has the function of true bipolar system interconnection and guarantees electrical isolation between bipolar systems, thereby ensuring the safety of user power supply.

The invention provides a kun type mixed polarity direct current power distribution system and a four-transformer QAB converter. A high-voltage side active bridge Hh1 is connected with the positive electrode of a high-voltage side bus, a low-voltage side active bridge Hl1 is connected with the positive electrode of a low-voltage side bus, a high-voltage side active bridge Hh2 is connected with the negative electrode of the high-voltage side bus, and a low-voltage side active bridge Hl2 is connected with the negative electrode of the low-voltage side bus; the high-voltage side active bridge Hh1 and the low-voltage side active bridge Hl1 are interconnected through a high-frequency transformer Tr1, and the high-voltage side active bridge Hh2 and the low-voltage side active bridge Hl2 are interconnected through a high-frequency transformer Tr2; the low-voltage side active bridge Hl1 and the high-voltage side active bridge Hh2 are interconnected through a transformer Te1, and the high-voltage side active bridge Hh1 and the low-voltage side active bridge Hl2 are interconnected through a transformer Te2. The kun type mixed polarity direct current power distribution system has a true bipolar system interconnection function, meanwhile, electrical isolation between bipolar systems is guaranteed, and power supply safety of users is guaranteed.

The application provides a method and system for simulating operation of a direct current power distribution system with an energy storage device, comprising: setting an initial value of a direct current voltage in the direct current power distribution system; reading a control mode of a voltage source converter and the energy storage device in the direct current power distribution system and a state of charge of the energy storage device; adjusting the control mode of the voltage source converter and the energy storage device according to the initial value of the direct current voltage in the direct current power distribution system and the state of charge of the energy storage device; and performing power flow simulation calculation on the power distribution system after the control mode of the voltage source converter and the energy storage device is adjusted. The method and system can effectively cope with the characteristics of the energy storage device in the direct current power distribution system, such as the changeable state of charge and the flexible adjustment of the control mode, and meet the power flow calculation requirements of the direct current power distribution system with the energy storage device.

The present invention relates to the technical field of power supply and distribution, and discloses a low-voltage flexible AC / DC distribution system. By arranging a first-level low-voltage flexible AC / DC distribution device and a first-level energy storage device in each single power user corresponding to a target power consumption station area, and arranging a second-level low-voltage flexible AC / DC distribution device and a second-level energy storage device in the target power consumption station area, on the one hand, surplus power generation is stored in a hierarchical manner, and on the other hand, the required power supply is allocated in a hierarchical manner, thereby realizing hierarchical coordinated distribution control of power supply and storage in the entire target power consumption station area, so that insufficient power storage supply can be supplied in time without the help of municipal power, and at the same time, a large amount of surplus power storage can be consumed locally, which greatly optimizes the distribution function of the existing low-voltage flexible AC / DC distribution system, not only reduces the electricity cost, but also avoids the waste of electric energy, improves the power supply and storage distribution control effect of the entire target power consumption station area, and has high practical value.

The invention provides a DC micro-grid insulation resistance monitoring device for an optical storage DC flexible system. The DC micro-grid insulation resistance monitoring device comprises a detection circuit and a controller communicating with the detection circuit. The device is connected to multiple paths of positive direct current buses including distributed photovoltaic branches and energy storage system branches in a direct current micro-grid through a Y-shaped connecting circuit, and relay logic is switched by utilizing a controller to obtain an output voltage signal. The core judgment logic is to compare whether the output voltage is in a reasonable interval defined by a coefficient gamma (the value can be dynamically adjusted according to the energy storage voltage grade) and the bus voltage, so that the insulation abnormity of the direct current micro-grid system under the flexible interaction working condition is quickly identified, and an alarm is given. According to the device, the operation process of multi-branch complex impedance is simplified, and the detection efficiency of the ground insulation state of the direct current end is remarkably improved.

The invention relates to a temperature control system control method and device, computer equipment and a storage medium, and relates to the technical field of temperature control. The method comprises the following steps: acquiring the bus voltage of a direct current power distribution system of a building where the temperature control system is located and the state information of the temperature control system, and determining the set temperature of the temperature control system by using a prediction model of the temperature control system according to the bus voltage and the state information; wherein model parameters of the prediction model are respectively related to the temperature control system and the building where the temperature control system is located, the temperature control system is controlled according to the set temperature, and the output power after the temperature control system is controlled is smaller than the output power when the temperature control system starts to be controlled. By adopting the method, flexible operation of the temperature control system can be controlled, power consumption is reduced, and the purposes of low power consumption and low carbon are achieved.

The invention discloses an optimal power flow calculation method for a multi-voltage-class bipolar direct-current power distribution system. The method comprises the following steps: 1, constructing a power flow decoupling model of a bipolar direct-current power distribution network; 2, constructing a direct current transformer DCT interelectrode decoupling and control model; 3, constructing a multi-voltage-level bipolar direct current optimal power flow model; 4, constructing an optimal power flow linearization and second-order cone relaxation model; and 5, obtaining the optimal power flow distribution of the system by solving the multi-voltage-level direct-current power distribution system network, and realizing stable and safe operation of the direct-current power distribution network. According to the method, the voltage quality of the direct current power distribution system can be ensured to be within an operation allowable range, so that the bipolar direct current power distribution network realizes higher electric energy quality and better power flow distribution, and safe and stable operation of the system is ensured.

The application discloses a direct current system grounding fault detection method and system, equal resistance is connected between the positive and negative bus of the direct current system and the ground to form a symmetrical resistance network, the positive / negative ground voltage and the branch ground current are collected in real time, the voltage deviation is calculated to generate a time domain fault mark, a high frequency component is extracted by wavelet transform and energy entropy analysis to generate a frequency domain mark, the ground current signal is subjected to wavelet transform and energy entropy calculation to extract a high frequency detail component, hierarchical collaborative decision is executed, double mark triggering immediately trips, single mark triggering starts a delay review mechanism, and after continuous triggering, tripping is executed and fault positioning and reporting are performed. The technical system improves the comprehensive identification speed of the direct current system grounding fault, forms a whole-process closed-loop protection of fast sensing and identification, reliable decision and accurate positioning, and improves the operation safety of the direct current distribution system.

To provide a processing device, etc. capable of efficiently controlling a value (passage current value) of passage current flowing through a DC distribution system.SOLUTION: A processing device is connected in a communicable manner with a storage battery unit disposed in a DC distribution system for distributing DC power obtained by converting AC power of an AC distribution system which is a power supply source. The processing device includes a processing unit that performs a process related to control of the storage battery unit. The processing unit acquires a value of passage current flowing through the DC distribution system, and changes output voltage from the storage battery unit according to the acquired passage current value and a predetermined upper limit current value.SELECTED DRAWING: Figure 1

The invention discloses a direct-current power distribution system energy mutual aid and power coordination control method, application and system, aiming at non-ideal disturbance, load fluctuation and parameter uncertainty existing in the system, VFESO is introduced, rapid estimation and compensation of generalized disturbance are realized through self-adaptive adjustment of observation gain and feedback bandwidth, and based on an observation result of the VFESO, the energy mutual aid and power coordination control of the direct-current power distribution system is realized. An improved reference feed-forward control law is designed, the reference current change rate and the disturbance observed quantity are comprehensively considered in the control law, a disturbance compensation item is directly introduced into control input, and feed-forward compensation and dynamic linearization of a current control loop are achieved; according to the invention, the system can maintain high-precision voltage and power control under the conditions of new energy fluctuation, energy storage switching and load disturbance.