43 results about "Reactive load" patented technology

The invention discloses a low-voltage reactive power compensation method and system for a power distribution device. The method comprises the steps that S10, reactive load data of all phases of the low-voltage side of the power distribution device are collected; s20, constructing a time sequence model of the reactive load of each phase of the low-voltage side of the power distribution device based on the reactive load data of each phase of a plurality of time nodes; s30, on the basis of the time sequence model, reactive load data of each phase of the next time node is predicted through exponential smoothing; and S40, based on the reactive load data of each phase of the next time node, determining the grouping switching condition of the reactive compensation capacitor of each phase of the power distribution device. According to the method, the reactive load data in the future is predicted based on the existing data through the exponential smoothing method, so that the adaptability to load fluctuation is improved, the response to emergency situations is enhanced, and the timeliness is higher.

The invention discloses a power semiconductor board-level test system and method, and belongs to the technical field of power semiconductor device test. According to the system, a reactive aging test and a dynamic characteristic test are creatively integrated on a single test platform, and the problems of low efficiency and high cost of a traditional substation test are solved through modular design. The system comprises a multifunctional test head arranged at a test station and capable of being connected with a power terminal and a signal terminal of a power module at the same time; the reactive load loop is formed by a three-phase adjustable reactor; the high-precision signal acquisition module comprises a flexible current probe and a differential voltage probe; the oscilloscope realizes multi-channel synchronous acquisition; and accurate control is realized based on the main control board card of the FPGA. According to the testing method, Vge, Vce, Ic and other parameters are collected in real time in the reactive aging process, online monitoring of dynamic characteristics is achieved through a current triggering mechanism, and a fault recording function is achieved.

A work machine using a direct current power system that isolates reactive loads is described herein. The work machine uses a machine power distribution unit that receives direct current power from two or more battery banks of a power unit, whereby each of the battery banks deliver electrical power on a separate direct current bus. A machine power distribution unit of the work machine receives the electrical power from the battery and is used to isolate the power using bus connectors. One of the battery banks provides power to one direct current bus of the work machine and another battery bank provides power to another direct current bus of the work machine. A reactive load serviced by one of the battery banks is electrically disconnected from another reactive load serviced by the other battery bank.

The present invention discloses a STATCOM system and a control method for a cascaded H-bridge without electrolytic capacitors, belonging to the field of power electronic control. The system comprises: a three-phase power grid, a three-phase reactive load, a filtering inductor and a three-phase cascaded N Buck multiplexing type H-bridge, N≥2; the Buck multiplexing type H-bridge comprises: an H-bridge composed of switch tubes S1-S4, a decoupling inductor L r , two film capacitors C d and C r , C r Passing by L r The midpoint of the second bridge arm of the H bridge is connected to form a bidirectional Buck circuit, and the bidirectional Buck circuit and the second bridge arm of the H bridge realize switch tube multiplexing; the midpoint of the first bridge arm of the H bridge is connected to the midpoint of the second bridge arm of the previous H bridge, and the three phases are connected in star shape. In the present invention, the bidirectional Buck circuit performs active power decoupling on the one hand, and the fluctuating power on the DC side of the H bridge is transmitted to the L r Transfer to auxiliary capacitor C r , thereby eliminating the double frequency fluctuation of the voltage on the DC side of the H-bridge, realizing the replacement of electrolytic capacitors with film capacitors, and at the same time assisting the first arm of the H-bridge to complete the power conversion on the AC and DC sides, thereby improving the power density and reliability of the device.

The invention relates to the technical field of switch cabinets, in particular to an intelligent low-voltage switch cabinet which comprises a cabinet body. The execution unit comprises a circuit breaker handcart used for disconnecting the current of the load circuit and a plurality of contactors used for switching the load circuit; the detection unit is used for detecting the instantaneous reduction voltage of the load, the current harmonic phase difference of the phase current signal of the main bus, the current harmonic signal proportion and the environment temperature in the cabinet body; the control unit is used for determining a load protection grade according to the instantaneous reduction voltage of the load, and determining the interval duration of starting the circuit breaker handcart and the contactor in the inrush current impact compensation mode according to the load protection grade and the duration of the instantaneous reduction voltage; the asynchronous action starting mode of the contactors is adjusted according to the harmonic wave phase difference, and the access proportion of the reactive load is adjusted according to the harmonic wave signal proportion and the progressive increase node similarity of the environment temperature in the cabinet body in the time sequence. According to the invention, the load stability is improved.

An antenna of a communication device includes a first antenna element operatively coupled to a transmitter of the communication device, the first antenna element configured to radiate a first signal generated by the transmitter; a second antenna element operatively coupled to a receiver of the communication device, the second antenna element configured to receive signals; and at least one third antenna element operatively coupled to at least one first reactive load, the at least one third antenna element configured to radiate a second signal modified in accordance with the at least one first reactive load, the second signal being induced at the at least one third antenna element by the first signal, and the at least one first reactive load being configured to modify the second signal to destructively cancel with a third signal induced at the second antenna element by the first signal.

According to one embodiment, a power amplifier includes a plurality of switches and an output tank network. One or more of the switches are configured to generate one or more first intermediate waveforms having one or more first fundamental frequency components, and one or more of the switches are configured to generate one or more second intermediate waveforms by chopping the one or more first intermediate waveforms with controllable timing. The second intermediate waveforms have one or more second fundamental frequency components that are controllably reduced from those of the one or more first intermediate waveforms. The output tank network is configured to filter the one or more second intermediate waveforms to provide an output waveform to a load, the output waveform having one or more third fundamental frequency components. In some cases, all switches achieve zero voltage switching under different power and load conditions with resistive and reactive loads.

The invention provides a method for improving circulating current stability of an off-grid parallel operation system. According to the method for improving the circulating current stability of the off-grid parallel operation system, the phase-locked loop is used for calculating the rotation angle of the output voltage of the converter, and the rotation angle is used for dq conversion of a voltage and current loop, calculation of the average active power Px and the average reactive power Qx and calculation of virtual inductive reactance negative sequence d-axis voltage drop and q-axis voltage drop; an off-grid local oscillation angle of the converter is used as a rotation angle, so that the off-grid local oscillation angle is distinguished from the rotation angle, a control loop of the converter is not influenced by an output voltage positive-sequence q-axis component any more, and positive-sequence q-axis circulating current of the converter is effectively restrained; meanwhile, virtual inductive reactance is added in a negative sequence loop, the negative sequence circulating current of the converter is suppressed, effective suppression of parallel operation circulating current is achieved, the circulating current stability of an off-grid parallel operation system is improved, communication does not need to be added between the converters, and the adaptability of the converters to reactive loads is not affected.

A working machine (100) using a DC power system (700) that isolates reactive loads is described herein. A work machine (100) uses a machine power distribution unit (712) that receives direct current power from two or more battery packs of a power unit, where each of the battery packs delivers power on a separate direct current bus. A machine power distribution unit (712) of the work machine (100) receives power from the battery and is used to isolate power using the bus connector. One of the battery packs supplies power to one DC bus of the work machine (100), and the other battery pack supplies power to the other DC bus of the work machine (100). A reactive load powered by one of the battery packs is electrically disconnected from another reactive load powered by another battery pack.

The invention discloses a power system operation mode generation method and device, terminal equipment and a storage medium, and belongs to the technical field of operation mode generation, and the method comprises the steps: obtaining active power data, a preset network topology model and a reactive load of a first node of a power system in a preset long-scale time period, carrying out direct-current power flow calculation and reactive compensation to obtain operation mode data of a long-scale time period; performing frequency simulation on the operation mode data in the long-scale time period, and generating a power simulation curve; and extracting a minute-level active power value from the power simulation curve, calculating a reactive load of a second node and a second reactive injection amount according to the minute-level active power value, and then generating minute-level power system operation mode data. Through the implementation of the method and the device, the problem that in the prior art, due to the fact that a minute-level short-time-scale operation mode cannot be generated, safety and stability analysis is difficult to carry out on the electric power system more accurately can be solved.

The invention relates to an electric power system complex power load typical scene extraction method with or without supervision combination, which comprises the following steps of: acquiring reactive load data of nodes of an electric power system, preprocessing the reactive load data, and calculating weighted similarity among complex power loads by using a multi-scale similarity index; based on the weighted similarity among the complex power loads, performing class number optimization and pre-classification of the full-scene complex power loads by adopting unsupervised learning, and taking a classification result as a label; on the basis of the label, performing smooth correction on a complex power load classification boundary by adopting supervised learning to obtain a final classification result; and extracting a typical operation scene based on the final classification result. Compared with the prior art, the method has the advantages of being high in classification efficiency, capable of achieving more accurate classification and the like.

The invention discloses an electromechanical transient simulation method and system for the voltage stability of a power system, and the method comprises the steps: obtaining data after the system is disturbed, and obtaining a time constant when a load is disturbed to recover to a steady state, and a proportion coefficient related to a static active load and a reactive load through a parameter identification algorithm; listing a conventional ZIP static load model, constructing a dynamic ZIP load model by adopting a proportional integral differential link and an amplitude limiting link, and reflecting an input-output relationship between active and reactive loads and equivalent impedance; determining a system balance point according to a steady-state power flow calculation result, performing linearization processing on all dynamic equations of the whole network at the balance point to obtain a state space model, calculating a state matrix eigenvalue, and judging a voltage stability condition of a bus where a load is located according to a sign of a real part of a related eigenvalue; and performing dynamic time domain simulation on the adjusted system, applying N-1 or N-2 type line faults to the whole network, and simulating a possible voltage collapse scene of the system. And a theoretical support is provided for providing countermeasures after voltage instability.

The present invention relates to a method for predicting the load level of a branch line distribution transformer based on user-side smart meter data. The method calculates branch reactive power and line loss through the power flow relationship of the distribution network, and designs an algorithm for estimating reactive load based on the smart meter data. The distribution characteristics of the three-phase source and load of the distribution network are judged according to the data collected by the meter, and then the branch power flow is iteratively calculated at a fixed point in combination with the new energy output data and the network topology. When the voltage difference obtained by the iteration is within a preset range, accurate three-phase reactive load data is obtained. For a distribution network with asymmetrical distribution of three-phase source and load, the method further considers the line charging effect and combines the reactive load prediction data and active load collection data of the distribution network to evaluate the load level of the branch line distribution transformer. The method solves the problem that the load level of the branch line distribution transformer is difficult to accurately evaluate due to the inability to directly measure the reactive load on the user side of the distribution network, thereby significantly improving the automation level of the distribution network and the safe and stable operation of the distribution network.

A work machine using a direct current power system that isolates reactive loads is described herein. The work machine uses a machine power distribution unit that receives direct current power from two or more battery banks of a power unit, whereby each of the battery banks deliver electrical power on a separate direct current bus. A machine power distribution unit of the work machine receives the electrical power from the battery and is used to isolate the power using bus connectors. One of the battery banks provides power to one direct current bus of the work machine and another battery bank provides power to another direct current bus of the work machine. A reactive load serviced by one of the battery banks is electrically disconnected from another reactive load serviced by the other battery bank.

The present invention discloses a method and system for simulating the electromechanical transient state of power system voltage stability. The method obtains data after the system is disturbed and uses a parameter identification algorithm to obtain the time constant for the load to recover to a steady state, as well as the proportional coefficients related to the static active load and reactive load. A conventional ZIP static load model is listed, and a dynamic ZIP load model is constructed using a proportional-integral-differential (PID) and a limiting step to reflect the input-output relationship between active and reactive loads and equivalent impedances. The system equilibrium point is determined based on the results of steady-state power flow calculations, and all dynamic equations of the entire network are linearized at the equilibrium point to obtain a state-space model. The eigenvalues ​​of the state matrix are calculated, and the voltage stability of the busbar where the load is located is determined based on the positive and negative signs of the real parts of the relevant eigenvalues. A dynamic time-domain simulation is performed on the adjusted system, and an N-1 or N-2 line fault is imposed on the entire network to simulate the voltage collapse scenario that may occur in the system. This provides theoretical support for proposing countermeasures after voltage instability.

The embodiment of the invention discloses a capacitor grid connection point determination method and device, electronic equipment and a storage medium. The method comprises the following steps: acquiring a plurality of reactive load values of each node of the transformer area line and an impedance value between two adjacent nodes; determining a calculated load value of each node according to the plurality of reactive load values of each node; and determining a capacitor grid connection point according to the impedance value between the two adjacent nodes and the calculated load value. The technical scheme provided by the embodiment of the invention not only considers the reactive load value and the impedance value of each node of the transformer area line, but also considers the calculation difficulty of selecting the grid-connected point, can reasonably determine the grid-connected point of the transformer area line, improves the power quality of the transformer area, reduces the power loss of the transformer area, is simple in process, is low in calculation difficulty, and is suitable for popularization and application. And the project progress is improved.

This invention discloses a method, device, electronic equipment, and storage medium for real-time reactive power control in distribution networks based on co-simulation, belonging to the field of smart distribution network operation control. The method includes: acquiring real-time active power values ​​of each photovoltaic inverter in the distribution network, as well as real-time active load values ​​and real-time reactive load values ​​of each load node; generating an initial population containing multiple sets of reactive power control vectors based on the real-time active power values; determining a target reactive power control vector from the initial population through iterative optimization, and controlling each photovoltaic inverter to adjust its power according to the target reactive power control vector. By implementing this invention, the problems of cumbersome modeling and difficulty in adapting to complex distribution network topology changes caused by relying on the construction of explicit mathematical models in existing technologies, and difficulties in convergence or even no solution in optimization under severe source-load fluctuations due to the use of hard voltage constraints, can be solved.

The embodiment of the invention discloses an energy storage equipment installation method and device, electronic equipment and a computer readable medium. A specific embodiment of the method comprises the steps of obtaining node topological data, parameter data of each line, a new energy output matrix, an active load matrix and a reactive load matrix; generating an active net injection power matrix and a reactive net injection power matrix; generating voltage deviation average data, an out-of-limit node number set, a node out-of-limit voltage sensitivity matrix and a power sensitivity matrix; generating a time sequence out-of-limit voltage sensitivity matrix; generating a time sequence power sensitivity matrix; determining an energy storage access point data sequence of the energy storage equipment; and controlling the mechanical arm to mount the at least one energy storage device to the corresponding at least one mounting point. According to the embodiment, waste of installation resources during installation of the energy storage equipment can be reduced.

A battery system configured to manage reactive energy transfer between battery cells, which includes a switching circuit configured to selectively connect any one or more the battery cell modules with the reactive circuit and configure the relative polarity of each battery cell module connected with the reactive circuit. A controller is configured to operate the switching circuit in a first mode and a second mode, where in the first mode, the controller is configured to connect one or more of the battery cell modules through the reactive circuit to an output for an external load, and in the second mode, the controller is configured to disconnect the battery cell modules from the output and drive a reactive current in the reactive circuit by alternately connecting selected one or more battery cell modules with the reactive circuit in a polarity that influences the reactive alternating cunent phase.

The present application discloses a method for predicting the optimal power flow of an electric power system taking into account topology changes, including: obtaining a data set, the data set including the amplitude and phase angle of the active load, reactive load, and self-admittance matrix of each generator node in different power node network topologies when the power system node network topology changes; using a convolutional neural network and an attention mechanism to extract features from the data set; based on the extracted features, using a convolutional neural network to directly predict to obtain the first predicted active power of the corresponding generator node; and, based on the extracted features, using a power equation to calculate the second predicted active power of the corresponding generator node; fitting the first predicted active power and the second predicted active power to obtain a third predicted active power, and using the third predicted active power as the solution to the optimal active power achieved by the optimal power flow of the electric power system. The present application can achieve fast and accurate prediction of a power node network with a changed topology.

This invention discloses a distributed AC optimal power flow solution method based on a multi-branch neural network, comprising: establishing an AC optimal power flow model; modeling the power system as a weighted graph based on complex network theory, and using the Louvain algorithm to perform community partitioning on this weighted graph; training a multi-branch DNN model for the entire power system, and using this model to learn the mapping relationship between input features and output features; using the trained DNN model to provide predicted voltages of non-zero injected nodes in the region using input features; calculating the voltages of ZigBs (Zones of Injection) using the Kron simplification method; obtaining predicted active and reactive load values ​​based on the voltages of the ZigBs and the provided load, and obtaining the demand load through the predicted load values. This invention can effectively reduce the network size, improve training efficiency, and enhance the accuracy of the solution. Furthermore, its flexibility and robustness make it more capable of handling future complex power system optimization tasks.

Antenna array system (1) comprising: - a powered main antenna (30) configured to emit a beam directed along a plurality of main directions, said powered main antenna operating in a first frequency band; - an array of parasitic antennas (10.1, 10.2, 10.3, 10.4) arranged to form a first envelope concentrically surrounding the main fed antenna (30), each antenna comprising a substrate of dielectric material (13.1, 13.2, 13.3, 13.4) having one face oriented outwards from the envelope provided with a parasitic radiating element (11.1, 11.2, 11.3, 11.4) and provided with a ground plane, the parasitic radiating element (11.1, 11.2, 11.3, 11.4) being connected to the ground plane via a reactive load (12.1, 12.2, 12.3, 12.4), each parasitic antenna being configured to emit a beam directed along a principal direction, the reactive loads (12.1, 12.2, 12.3, 12.4) being configured to selectively activate electromagnetic coupling between the main fed antenna and a pair of parasitic antennas to modify the directivity of the main fed antenna. Abstract figure: Figure 1.

The invention discloses an inverter switching time test method and device, equipment and a storage medium. The method comprises the following steps: acquiring a target power value, controlling the operation of electrical equipment based on the target power value, and putting a reactive load into work; respectively acquiring a first waveform and a second waveform of an alternating current input end and an alternating current output end of the inverter by utilizing acquisition equipment; after the contactor is disconnected, acquiring a third waveform and a fourth waveform of the alternating current input end and the alternating current output end of the inverter respectively by utilizing acquisition equipment; and obtaining an inverter input waveform based on the first waveform and the third waveform, obtaining an inverter output waveform based on the second waveform and the fourth waveform, and determining the switching time of the inverter according to the inverter input waveform and the inverter output waveform. According to the scheme, the dynamic characteristics of the switching process are precisely restored through dual-channel waveform acquisition, the response capability and the switching performance of the inverter in a power-off scene are effectively evaluated, and the method is suitable for performance testing of scenes such as a distributed optical storage system and household emergency power supply.

1. Name of the product in this design: High-voltage capacitor switching switch. 2. Application of this design: This design is used for the frequent switching on and off of high-voltage active or reactive loads. 3. The key design feature of this product is its shape. 4. The image or photograph that best illustrates the design's key points: 3D view 1.

A work machine (100) using a direct current power system (700) that isolates reactive loads is described herein. The work machine (100) uses a machine power distribution unit (712) that receives direct current power from two or more battery banks of a power unit, whereby each of the battery banks deliver electrical power on a separate direct current bus. A machine power distribution unit (712) of the work machine (100) receives the electrical power from the battery and is used to isolate the power using bus connectors. One of the battery banks provides power to one direct current bus of the work machine (100) and another battery bank provides power to another direct current bus of the work machine (100). A reactive load serviced by one of the battery banks is electrically disconnected from another reactive load serviced by the other battery bank.

According to one embodiment, the power amplifier includes a plurality of switches and an output tank network. One or more of the plurality of switches are configured to generate one or more first intermediate waveforms having one or more first fundamental frequency components, and one or more of the plurality of switches are configured to generate one or more second intermediate waveforms by chopping one or more of the first intermediate waveforms at a controllable timing. The second intermediate waveforms have one or more second fundamental frequency components that are controllably reduced from the fundamental frequency components of one or more first intermediate waveforms. The output tank network is configured to filter one or more second intermediate waveforms to provide an output waveform having one or more third fundamental frequency components to the load. In some cases, all switches achieve zero-volt switching under different power and load conditions with resistive and reactive loads.

The invention belongs to the technical field of mining power supply and distribution equipment, and particularly relates to an underground centralized reactive power compensation device which comprises an explosion-proof shell, and a three-phase cable connector is arranged on the explosion-proof shell. A vacuum alternating current contactor, a water-cooled reactor, a power unit, a buffer alternating current contactor, a buffer resistor, a control cabinet, a first current transformer and a power supply module for supplying power to the whole device are arranged in the explosion-proof shell, the whole reactive power compensation device is arranged underground, and each underground bus section is provided with one reactive power compensation device; according to the invention, centralized compensation is carried out on the underground reactive load generation source, so that the total load and the total current of an underground power supply system can be greatly reduced; through accurate reactive compensation, the device can improve the power factor of an underground power supply system and reduce voltage fluctuation and current harmonics, thereby improving the stability and reliability of the power supply system. The method is of great significance in guaranteeing safe production of mines.

The utility model relates to the technical field of power distribution line ice melting, in particular to an on-load line ice melting structure and a control system based on a reactive compensation principle, which comprises a line load comprising N sections of sub-lines connected in sequence, and N is a natural number greater than or equal to 1; and the compensation module comprises a reactive power supply and a reactive load, the reactive power supply is connected to the front end of each section of sub-circuit, and the reactive load is connected to the tail end of each section of sub-circuit. The beneficial effects of the utility model are that the operation strategy is adjusted in real time according to the operation condition of the line, four control modes including a line protection mode, an ice melting mode, a voltage regulation mode and a standby mode are provided, the voltage stabilization characteristics of the capacitor and the reactance can be fully utilized, and the ice melting function of the line can be realized under the condition that the line is not stopped.

The invention discloses a power-traffic coupling system prevention and control method for toughness improvement. The method comprises the following steps: 1) obtaining network parameters and operation parameters of a power system and a traffic system; 2) acquiring scene data, including active load and reactive load of a power system, travel demands of different starting and ending points in a traffic system, and proportions of electric vehicles; 3) based on the acquired network parameters, the operating parameters and the scene data of the two systems, constructing an operating constraint under a conventional working condition and an operating constraint under a fault working condition; and 4) based on the constructed constraint, taking a price signal and distributed power supply output as regulation and control objects, and taking minimization of the operation cost of the two systems under a conventional working condition as a target function, establishing a power-traffic coupling system prevention and control model oriented to toughness improvement, and solving to obtain a prevention and control strategy for ensuring the operation safety of the power-traffic coupling system after the fault.

The invention provides a transient voltage stability evaluation method and system. The method comprises the following steps: establishing a transient voltage stability time domain simulation model meeting the voltage support capability of a power transmission and distribution network connection point; the time domain simulation model comprises a synchronous generator model, a dynamic load model, a network topology structure model and a fault model; solving the time domain simulation model to obtain voltage support capability data of the power transmission and distribution network connection point; the historical power system data and the voltage supporting capability data form training data; training the convolutional neural network by using the training data; inputting the active power, the reactive load, the active load and the key voltage area node voltage of the synchronous generator into the trained network input layer; and outputting a transient voltage collapse index and a voltage deviation severity index at an output layer to realize transient voltage stability evaluation. Based on the method, the invention further provides a transient voltage stability evaluation system. According to the invention, efficient and accurate quantification of the transient stability index can be realized.