9results about How to "Improve voltage quality" patented technology

The invention discloses a multi-standard power supply system and method for a locomotive test, and relates to the technical field of test power supplies, and the structural design of the system is as follows: an input power supply is a three-phase alternating current 10kV power supply; the high-voltage switch K realizes access control and isolation of the system and a public power grid, the connection reactor L realizes energy buffering and inhibits switch ripples in output current, and the soft charging circuit pre-charges the three-stage converter. The three-level converter converts three-phase alternating current 10kV into DC1500 / 750V and outputs the DC1500 / 750V to the direct-current bus, one path of the direct-current bus supplies power to a subway vehicle test line, and the other path of the direct-current bus is inverted into single-phase alternating current 25kV through the output inverter and supplies power to a railway locomotive test line. According to the invention, alternating current test conditions of railway electric traction locomotive vehicles and direct current test conditions of subway vehicles can be satisfied, reliability and quality of power supply are ensured, repeated construction is reduced, and resource waste is avoided.

The invention discloses an operation state regulation and optimization method for a power distribution network containing a distributed power supply and a flexible load, and the method comprises the following steps: obtaining a topological structure and operation parameters of the power distribution network, and constructing a power distribution network operation state regulation model according to the topological structure and the operation parameters; on the basis of a power distribution network operation state regulation and control model, a traditional knowledge acquisition sharing algorithm is improved, and a spiral updating strategy is introduced to guide a search individual to approach a current candidate optimal solution along a spiral trajectory; and performing iterative solution on the operation state regulation and control model by using an improved knowledge acquisition sharing algorithm to obtain operation optimization configuration of the power distribution network. According to the method, the global search capability and the local convergence precision of the algorithm are remarkably improved, so that the operation optimization configuration can be quickly and accurately obtained, and the stability, the adaptability and the overall operation performance of the power distribution network when the power distribution network deals with renewable energy output fluctuation and load change are enhanced.

The present application relates to the technical field of power distribution network planning, and more particularly to a power distribution network multi-resource integrated planning method and system based on a graph neural network. The method comprises the following steps: collecting the operation and geographic data of the distribution transformers, feeder switches, 10kV feeders and each load access point in the target planning area to form a basic planning data set; constructing a power distribution network topology graph and using a graph neural network to identify overloaded feeder sections, low-voltage end sections and overloaded transformer nodes; then, according to the spatial position and power supply correlation of each problem area, determining the distribution transformer capacity expansion layout, tie switch addition and line extension reconstruction path; and finally, optimizing and outputting the target area planning scheme through power flow checking. The present application identifies the weak links of the power distribution network through a graph neural network and cooperatively optimizes the capacity expansion layout, tie transfer and line extension path, thereby achieving the precision, collaboration and economy of power distribution network planning and significantly improving the power supply capacity and overall operation reliability.

The invention relates to the technical field of power grid dispatching, in particular to an active-reactive collaborative optimization dispatching method for a power distribution network. Acquiring voltage, active power and power grid line data at the uploading moment of the user side and various monitoring data of the transformer substation in a preset time period; because the user side data and the transformer substation side data are in space-time asymmetry and have measurement blind areas, various data numerical value characteristics are fused and analyzed and compared with the user side voltage, a voltage-power transmission coefficient is determined, an accurate voltage prediction model is constructed, and the voltage prediction value of the user side at each preset moment is obtained; as the time goes on or the photovoltaic fluctuates greatly, the error increases, so that the active power change in the preset time period and the active power difference of the user side at the to-be-measured moment are corrected based on the difference characteristics of the transformer station monitoring data, and the corrected available capacity of the inverter is obtained; and determining an adjustment burden index by combining the voltage predicted value, and finally adjusting the transformer according to an index accumulation condition and the voltage predicted value.

The application discloses a kind of low-voltage distribution network governance device and method without CT voltage tracking, including three-phase four-wire transformer, the three-phase power line of pure three-phase load (1) is connected with the three-phase line of transformer corresponding, power quality management equipment (2) is accessed to the three-phase four-wire circuit of transformer, for balancing the voltage of three-phase line;Resistance component is accessed to the three-phase four-wire of transformer, in the front end of power quality management equipment (2), for adjusting the current and voltage in three-phase circuit, the application solves the comprehensive treatment of reactive power compensation, three-phase imbalance and end low voltage, overvoltage of distribution network in the case of canceling CT, ensure the efficient and economic operation of distribution network line, improve voltage quality;While reducing secondary accidents caused by equipment power quality management equipment itself failure, with reliable, convenient, safe and cost-reducing technical effect.

This invention relates to the field of microgrid control technology, and discloses a distributed harmonic control method, device, and multi-inverter system for multi-inverter systems. In this invention, adjacent inverter control units are connected to form a ring network. During harmonic control, the output voltage and output current of the inverter in the inverter control unit are used to separate the fundamental and harmonic components. Based on the obtained fundamental component, the fundamental component of the outer loop reference voltage is calculated. The harmonic power is calculated based on the harmonic current component. Combined with the harmonic power of other interconnected units, a harmonic power sharing controller is calculated to determine the harmonic voltage gain coefficient. Based on this coefficient and the harmonic current component, the harmonic component of the outer loop reference voltage is obtained. The outer loop reference voltage is then calculated, and the control voltage for the corresponding three-phase inverter bridge is obtained from this reference voltage. This invention is unaffected by grid interference and feeder impedance mismatch, compensates for voltage distortion caused by nonlinear loads, and achieves precise harmonic power distribution between the DG (Distributed Generator and Controller).

The application relates to the technical field of source network load storage, and discloses a source network load storage coordination method, which comprises the following steps: dividing an electric power network into multiple basic control areas; evaluating a first electrical coupling strength index between the basic control area and its adjacent area; if the first electrical coupling strength index is greater than or equal to a coupling threshold value for a first duration, then the associated basic control area is combined into a coordinated control group, and a regional coordination controller is selected as a master controller of the coordinated control group; evaluating a second electrical coupling strength index between each basic control area in the coordinated control group; if the second electrical coupling strength index between the areas is less than the coupling threshold value for a second duration, then the coordinated control group is dissolved, and each basic control area is switched back to an operation mode independently managed by the configured regional coordination controller. The source network load storage coordination method realizes coordinated control by monitoring the coupling strength between the areas in real time.

The present application discloses a power conversion system and a communication method thereof for transmitting common mode information. The communication method comprises the following steps: (a) providing at least two power conversion units, the first ends of which are electrically coupled, and each power conversion unit comprising a resonance control unit; (b) each power conversion unit generating an alternating harmonic wave according to a first electrical signal at the first end thereof, wherein the amplitude of each alternating harmonic wave represents the first information of the corresponding power conversion unit, and the frequencies of all alternating harmonic waves are the same; (c) injecting the corresponding generated alternating harmonic wave at the first end of each power conversion unit, and using the resonance control unit in the power conversion unit to carry out closed-loop suppression on the corresponding generated alternating harmonic wave, and controlling the resonance control unit to output a second electrical signal related to the first information, which comprises common mode information or is capable of further generating common mode information with the injected alternating harmonic wave. The present application can transmit common mode information without relying on additional communication lines.

This invention relates to the field of power optimization technology, specifically disclosing a virtual power plant optimization operation method based on multi-energy coupling. The method includes: extracting the thermal damping characteristics of each target node in a building complex and calculating the energy repayment demand; simulating the power superposition effect of simultaneous startup of multiple nodes, verifying safety constraints by combining grid transformer capacity limitations and ramp rate, and extracting the rebound risk time window; analyzing the user's thermal comfort tolerance limit and energy repayment demand, and dividing the heterogeneous recovery echelons; performing time-series optimization on each echelon to determine the optimal start-stop time group; analyzing latent cooling potential energy in real time and performing conflict analysis with remaining sensible heat demand, and predictively intercepting and dynamically reducing oversaturated redundant nodes. This invention helps to smooth out the rebound peak during the load recovery period and utilizes building thermal inertia, ensuring both grid safety and user comfort.