7results about How to "Guarantee power quality" patented technology

This invention provides a microgrid power coordination method and system based on state-enhanced Kalman filtering, relating to the fields of new energy, power electronics, power conversion, and control technologies. The method includes: constructing a state-space model of an AC microgrid and modeling feeder impedance as an augmented state, thus constructing an augmented state-space model of the AC microgrid; based on the augmented state-space model, using an improved Kalman filtering algorithm, calculating the optimal estimate of the feeder impedance of each distributed power source unit, and using an optimal impedance adjustment algorithm to calculate the virtual impedance of each distributed power source unit; and adjusting the output voltage of each distributed power source unit according to its virtual impedance to achieve reactive power regulation of the AC microgrid. This invention effectively solves the problem of the difficulty in directly obtaining feeder impedance in practical engineering and compensates for feeder impedance mismatch by allocating virtual impedance, thereby achieving reactive power balance in the AC microgrid.

The application belongs to the technical field of power system operation and control, and specifically discloses a distributed energy optimization scheduling method and system based on reinforcement learning, which comprises the following steps: obtaining a distribution network parameter calculation sensitivity matrix, combining real-time measurement data of each node, and fusing to generate a joint scheduling state containing topological coupling information; inputting the state into a reinforcement learning intelligent agent to output an initial collaborative scheduling action; simultaneously constructing a linearized action safety boundary based on the sensitivity matrix and a safety threshold, projecting the initial action into the boundary, and generating a safety scheduling instruction after over-limit checking; and finally converting the safety scheduling instruction into a droop control bias and issuing it for execution. The application combines global collaborative optimization of an intelligent algorithm and deterministic constraints of a physical model, improves overall operation economy on the premise of ensuring that the distribution network meets safe operation constraints.

This invention discloses an unmanned intelligent photovoltaic green electricity distribution device for mines, featuring source-grid-load-storage coordination. The device includes a base, with a nested shock-absorbing assembly at the top. Above the nested shock-absorbing assembly is an energy storage distribution box. An energy storage interface compartment is connected to the left side of the energy storage distribution box, and a distribution control box is located on the right side. A flexible connection assembly is positioned above the energy storage distribution box, and a source-grid adapter box is located above the flexible connection assembly. A dual-path photovoltaic rectifier compartment is located on the left side of the source-grid adapter box, and a mine microgrid connection compartment is located on the right side. Utilizing the dual-path photovoltaic rectifier compartment within the source-grid adapter box, synchronous conversion of two photovoltaic DC power sources is achieved, improving power conversion efficiency and filtering power noise. The mine microgrid connection compartment integrates voltage regulation and lightning protection functions, enabling efficient connection with the mine microgrid.

The application provides a primary frequency modulation method of a hybrid energy storage thermal power generating unit based on a flywheel energy storage device, and the method comprises the following steps: calculating a target power increment required for primary frequency modulation of the thermal power generating unit according to a frequency value of a power grid bus; collecting a real-time rotating speed of the flywheel energy storage device, and calculating a maximum power increment that can be output by the flywheel energy storage device in real time according to the real-time rotating speed; calculating a maximum power increment that can be output by a lithium battery energy storage device in real time according to a rated power value and a real-time power value of the lithium battery energy storage device; and dynamically allocating the power increments provided by the flywheel energy storage device, the lithium battery energy storage device and the generating unit in the primary frequency modulation in combination with the actual power regulation capabilities of the flywheel energy storage device and the lithium battery energy storage device and the rotating speed of the generator. The method involves the energy storage resources in the automatic power generation control of the generator unit, improves the frequency modulation effect and increases the frequency modulation response speed.

The invention provides a microgrid power collaboration method and system based on novel state augmented Kalman filtering, and relates to the technical field of new energy and power electronic energy conversion and control. The method comprises the following steps: constructing a state space model of an alternating current micro-grid, modeling feeder impedance into an augmented state, and constructing an augmented state space model of the alternating current micro-grid; based on the augmented state space model, adopting an improved Kalman filtering algorithm to calculate an optimal estimated value of feeder impedance of each distributed power supply unit, and adopting an optimal impedance adjustment algorithm to calculate virtual impedance of each distributed power supply unit; and adjusting the output voltage of each distributed power supply unit according to the virtual impedance of each distributed power supply unit so as to realize reactive power adjustment of the AC micro-grid. According to the method, the problem that the feeder impedance is difficult to directly obtain in actual engineering is effectively solved, mismatch of the feeder impedance is made up by distributing the virtual impedance, and reactive power balance of the alternating-current micro-grid is achieved.

The invention discloses a double-variant collaborative self-adaptive control method for virtual inertia and damping parameters of a GFM inverter under a weak power grid, and the method comprises the steps: based on a photovoltaic power generation device, an inverter and an LC filter which are connected in sequence, the photovoltaic power generation device outputs a direct current, the inverter converts the direct current into an alternating current, and the high-frequency harmonic wave is filtered through the LC filter; and the grid-connected point is connected into an alternating-current power grid through an equivalent inductor. The method specifically comprises the following steps: step 1, acquiring an electrical quantity in real time based on a network-forming inverter; step 2, the DSP control module obtains a power grid short-circuit ratio and an active power change rate through voltage, current and active power data; 3, presetting a parameter matrix of virtual inertia and virtual damping corresponding to different short-circuit ratios and active power change rates; and 4, comparing whether the data change exceeds 5%, and judging whether to enter a parameter adaptation process. According to the method, secondary disturbance of parameter switching is eliminated, system frequency oscillation and electric energy quality deterioration are inhibited, and the dynamic response performance is remarkably improved.

The invention provides a grid-connected inverter harmonic suppression method based on double-vector model predictive control, and the method comprises the steps: building an inverter prediction model under an alpha-beta static coordinate system, separating an output current into a fundamental component and a harmonic component, and carrying out the prediction control of the fundamental component and the harmonic component; a dual-target optimization function containing a fundamental wave weight coefficient eta and a harmonic wave weight coefficient gamma is constructed, minimization of an error area between PCC harmonic current and a zero axis is taken as a harmonic suppression target, and a dual-vector model is combined to predict and control a dynamic optimal voltage vector and action time thereof, so that coordinated optimization of fundamental wave power transmission and harmonic suppression is realized. The method can effectively reduce the total harmonic distortion rate at the PCC, improves the electric energy quality of a multi-inverter parallel system, and is suitable for an alternating current bus system containing multiple harmonic sources.