269 results about "Pv power" patented technology

A system for generation of electrical power including an inverter connected to a photovoltaic source including a theft prevention and detection feature. A first memory is permanently attached to the photovoltaic source. The first memory is configured to store a first code. A second memory is attached to the inverter. The second memory configured to store a second code. During manufacture or installation of the system, the first code is stored in the first memory attached to the photovoltaic source. The second code based on the first code is stored in the second memory. Prior to operation of the inverter, the first code is compared to the second code and based on the comparison; the generation of the electrical power is enabled or disabled.

In large PV power plants, grounding of individual PV modules may lead to problems. The present invention overcomes such problems. The basis for the invention is a PV power plant comprising one or more PV generators, each comprising a PV string and an inverter with a DC input and an AC output. The PV string comprises at least one PV module and is electrically connected to the DC input of the inverter. The inverter comprises means for controlling the DC potential at the DC input depending on the DC potential at the AC output. The AC outputs of the inverters are coupled in parallel. The novel feature of the invention is that the PV power plant further comprises an offset voltage source, which controls the DC potential at the AC outputs. Thereby, the DC potential at the DC input will be indirectly controlled, and it is thus possible to ensure that the potentials with respect to ground at the terminals of the PV modules are all non-negative or all non-positive without grounding the PV modules. Ground loops can be avoided, and there is no need for the use of transformer-based inverters.

In the invention, the master station installed in the remote monitor center makes data communication with the far-end station installed in the solar PV power station; the master station sends the configuration instruction of the remote end monitor center to the far end station through the satellite repeater, and receives the data of far end station through the satellite repeater; the far end station is used for collecting the data about the running state of the PV power station, and converting the collected analog data into the digital data, and sends the digital data through antenna; under the control of the master station, the service channel sends the collected digital data to the master station through satellite; the administration computer processes the data and provides the data for the remote monitor center.

A micro inverter includes a synchronous bi-directional power converter and a controller communicatively coupled to the synchronous bi-directional power converter. The controller is configured to operate the micro inverter in a forward conduction mode when photovoltaic (PV) power is available and operate the micro inverter in at least one of a reverse conduction mode and a reactive power compensation mode when PV power is unavailable.

The invention discloses a PV (Photovoltaic) power generation system and a fault detection method thereof. The photovoltaic power generation system comprises at least one PV power generation and a central server which is communicated with the PV power generation through an internet. Each PV power generation comprises a plurality of PV power generation arrays, a first coordinator and a first gateway, and each PV power generation array comprises a plurality of PV power generation nodes and PV routing nodes wirelessly communicated with the PV power generation nodes; the first gateway is connected with the first coordinator and is used for determining the operating statuses of all PV power generation arrays according to statuses parameters received from the first coordinator, and transmitting the received status parameters and the determined operating statuses to the central server. According to the PV power generation system and the fault detection method thereof provided by the invention, abnormal modules can be discovered at the first time, the influence on the integral system caused by the abnormal components can be reduced, and the safety and service life of the system can be improved.

Photovoltaic (PV) power converters including an LLC converter stage are described. A PV power converter includes a LLC converter stage and a controller. The LLC converter stage includes an input for receiving a direct current (DC) power input from a PV module, a first transformer having a primary winding and a secondary winding and defining a DC side and an alternating current (AC) side of the PV power converter, a plurality of switches on the DC side of the first transformer, and an output coupled to the secondary winding of the first transformer to provide a DC power output. The plurality of switches is coupled between the primary winding of the first transformer and the input. The controller is located on the AC side of the PV power converter. The controller is operatively connected to the plurality of switches and configured to control operation of the plurality of switches.

The invention discloses a photovoltaic power interval prediction method combining a deep cycle neural network and parameter estimation, belonging to the technical field of photovoltaic power prediction. The method of photovoltaic power forecasting based on a long-term and short-term memory network firstly chooses the data of product day, ambient temperature, ambient humidity, wind speed and solarirradiance as the original data of photovoltaic power forecasting. The data of product day, ambient temperature, ambient humidity, wind speed and solar irradiance are selected as the original data ofphotovoltaic power forecasting. The confidence intervals of PV power values and predicted values corresponding to 24 hourly hours of the predicted day are outputted from the predicted model to 24 hourly hours of the predicted day for 365 days of the year. This method establishes a relationship between the current photovoltaic power change and the previous photovoltaic power change, realizes the dynamic modeling of the time series data, and can reflect the change law of photovoltaic power more fully, and realizes more accurate photovoltaic power prediction. The method is easy to operate, is high in practicability and has a high promotion value.

A distributed photovoltaic (PV) power plant includes a plurality of distributed dc-dc converters. The dc-dc converters are configured to switch in coordination with one another such that at least one dc-dc converter transfers power to a common dc-bus based upon the total system power available from one or more corresponding strings of PV modules. Due to the coordinated switching of the dc-dc converters, each dc-dc converter transferring power to the common dc-bus continues to operate within its optimal efficiency range as well as to optimize the maximum power point tracking in order to increase the energy yield of the PV power plant.

The invention discloses a reactive optimization method for improving a qualified rate of a power distribution network comprising distributed photovoltaic power sources. The method mainly comprises the following steps: when the photovoltaic power sources work in an MPPT mode, by taking minimization of whole-network voltage deviations as a target, performing reactive optimization on residual capacities of photovoltaic inverters by use of a particle swarm algorithm; if an optimization result still comprises a node voltage off-limit condition, employing an improved optimization scheme: first of all, under the condition that it is ensured that whole-network voltages are qualified, by taking maximization of total active output of the photovoltaic power sources as a target, obtaining an optimal active value of each photovoltaic power source; and then by taking the result as an active output value of each photovoltaic power source and by taking the minimization of the whole-network deviations as the target, performing the reactive optimization on the residual capacities of the photovoltaic inverters again. According to the invention, operation economic benefits and reliability of the power distribution network are taken into integrated consideration, distribution of active and reactive output of the photovoltaic inverters is optimized, and the voltage qualified rate of the power distribution network comprising the photovoltaic power sources is effectively improved.

The present invention concerns a single stage inverter device for power converters, comprising switching means (M1-M4) capable to periodically connect an energy source, in particular a photovoltaic one, to an electric network or grid, the switching means (M1-M4) being controlled by controlling electronic means operating according to a single switching cycle control of the switching means (M1-M4), the operative and circuit device parameters being such to fulfill a series of constraints simultaneously optimizing both the maximum power point tracking or MPPT (Maximum Power Point Tracking) and the output power factor or PF-out (Power Factor-output) for one or more operation conditions. The present invention further concerns the related method of controlling and the related method of scaling such device.

The invention discloses a time sequence probability modeling method for output power of solar photovoltaic power supply and belongs to the technical field of probability modeling for output power of the power supply of an electric power system. The time sequence probability modeling method comprises the following steps of: firstly inputting measured data of the output power of the photovoltaic power supply and daily power output begin-end time by utilizing a computer through a program; then estimating a probability density function of the daily power output begin-end time of the photovoltaic power supply based on a nonparametric kernel density estimation theory, and generating a random sample; and then sequentially estimating the probability density function of the output power of the photovoltaic power supply at each time based on nonparametric kernel density estimation and conditional probability theories, and generating a random sample. The time sequence probability modeling method provided by the invention has the advantages of simplicity, strong practicality, high estimation accuracy, strong commonality, and convenience in popularization and application. The time sequence probability modeling method can be widely used for establishing a time sequence probability model of the output power of the photovoltaic power supply in the electric power system.

The invention relates to a combination optimizing method, considering dynamic frequency constraint, for an isolated power grid set comprising a high-permeability photovoltaic power supply. Dynamic frequency characteristic constraint is taken into consideration in a set combination optimizing model, and the load of a photovoltaic power supply is reduced and the frequency modulation capability of a system is enhanced if the photovoltaic power supply participates in frequency modulation. The method is based on an expression of the lowest point of dynamic frequency after an isolated power grid containing frequency modulation of the photovoltaic power supply, and the invention discloses an expression about the lowest point of dynamic frequency when the smallest frequency modulation capacity is needed by frequency modulation participation of the photovoltaic power supply to determine that the set combination model has the sufficient but not excessive photovoltaic power frequency modulation capacity during optimization. Moreover, the set combination optimizing model that contains the lowest point of dynamic frequency and the photovoltaic power frequency modulation capacity constraint is established. The invention brings forward the method for optimizing the inner layer and the outer layer of the optimizing model on the basis of decomposition to generate optimizing segments and through Benders decomposition. The problem-solving complexity is effectively reduced.

The efficiency of a PV power generation system (10) is maximised by an apparatus providing series of electronic units (20) connected to the PV modules (12) and comprising microprocessor controlled DC converters/power supply units. A managing unit (60) communicates with the electronic units (20) of a string (11) in order to carry out a synergic optimization of the efficiency both of the single PV modules (12) and of the entire string (11). The apparatus also provides PV module (12) by PV module (12) diagnostic features and it is able to communicate with external devices for a full system control.

The invention provides an automatic washing device and an automatic washing method for a solar PV component and belongs to the technical field of solar PV power stations. The device comprises a cleaning system, a solution filter system, a solution circulating system and a control system, wherein the cleaning system comprises a flushing pipe and a flushing orifice; the solution filter system comprises a hydrops tank and a filter wool; the solution circulating system comprises a liquid storage tank, a solution supply pump, a solution circulating pump and a plurality of connecting pipelines, the liquid storage tank is connected with the solution supply pump, the solution supply pump is connected with the flushing pipe, one end of the solution circulating pump is connected with the hydrops tank, and the other end of the solution circulating pump is connected with the liquid storage tank; the control system comprises a pollution sensor and a controller, the controller is in wireless connection with or in wired connection with the pollution sensor, the pollution sensor is used for sending signals to the controller when the measured value of pollution exceeds a threshold value, and the controller is used for controlling the starting and cleaning processes of the solution supply pump and the solution circulating pump according to signals of the pollution sensor. Due to the adoption of the scheme, the technical problems of low degree of automation, incapability of automatic selection of solution and low solution utilization ratio can be solved.

The invention relates to a method for controlling the small disturbance voltage stability of a microgrid system. The microgrid system controlled by the method comprises a photovoltaic power source, adiesel generator and a DFIG that are connected to one end of a 10kV bus. The control method includes the following steps of: 1) state variable acquisition, including the acquisition of a photovoltaicpower source state variable, the acquisition of a diesel generator state variable, and the acquisition of a DFIG state variable; 2) characteristic value calculation including combining the photovoltaic power source state variable, the diesel generator state variable, and the DFIG state variable to construct a system state space model and to obtain the characteristic value of a system state matrix;3) specific parameter determination including combining the acquired characteristic value and the change trend of a voltage dynamic response curve at a PCC point, and determining the specific parameter affecting the small disturbance voltage stability; and 4) voltage control including improving the specific parameter to improve the small disturbance voltage stability. Compared with the prior art,the method is simple and visual, reduced in cost, and high in control efficiency.

The invention discloses an evaluation method for photovoltaic power receptivity of a power distribution network. The method includes the following steps: firstly, creating indexes of the photovoltaic power receptivity of the power distribution network; secondly, performing magnitude unified processing on the indexes of the receptivity; thirdly, determining weights of the indexes of the receptivity. A provided comprehensive evaluation model for the photovoltaic power receptivity of the power distribution network considers many factors, the defect that an original model is high in subjectivity and single in evaluation perspective is overcome, and scientific bases are provided for selection of photovoltaic power connection schemes.

The invention relates to the technical field of planning and design of power dispatching systems, in particular to a wind-light-water complementary power generation plan calculation method based on power grid structure and cascade hydropower station hydraulic connection coupling in a mutual compensation operation mode of water power generation, wind power generation and photovoltaic power generation. The method comprises the following steps: establishing a layered structure covering a basin hydropower station, a wind power and photovoltaic physical power station and a power supply set according to a power delivery channel of the wind power, photovoltaic and cascade hydropower stations in the basin; on the basis of the established power station and power supply layered structure, establishing a wind-light-water complementary scheduling model which comprehensively considers a power station sending-out channel in a drainage basin and hydraulic connection between hydropower stations; and solving the models according to a hierarchical coordination method to meet the requirements of the cascade hydropower station and basin wind power and photovoltaic power complementary power generationoperation and plan making oriented to power grid operation.

The invention relates to a perturbation and observation method MPPT control method with a photovoltaic array self-adaptive step size. The control method includes the main steps that output voltage and currents of a photovoltaic array PV are sampled to obtain a P-U characteristic curve, PV end voltage corresponding to incomplete differential and PV end voltage corresponding to ideal differential are Ua and Ub respectively, and the PV end voltage is divided into an interval I (0-Ua), an interval II (Ua-Ub) and an interval III (>Ub). Forward disturbance is performed in the interval I with the step size of d1, reverse disturbance is performed in the interval II with the step size of (2 eta-1), and reverse disturbance is performed in the interval III with the step size of d1. Signal samples of a voltage sensor and a current sensor of a system are connected into a micro processor, all processing modules for executing the method are stored in a program storage unit, a pulse width modulation module (PWM) is connected into output of the micro processor, and the PWM outputs a drive signal to control a direct-current conversion circuit of the photovoltaic array to achieve maximum power point tracing. Tracing is carried out with the small step size close to the MPP and with the large step size in far intervals, the step size is adjusted in a self-adaptive mode, the antijamming capability is improved, PV power loss is effectively reduced, and the energy use ratio is effectively increased.

A DC collection system for a PV power plant contains a large number of feeders. When a fault occurs, the fault current rapidly increases, causing electronic devices to block to protect themselves. This blockage presents a challenge to the protection of the DC collection system because of extremely short data windows. To address this challenge, a protection method based on active control of DC/DC converters is disclosed. The fault current control principle is analyzed and derived so that DC/DC converters can provide an injected low-amplitude and controllable post-fault stable current signal. The disclosed protection method is designed based on identifying the direction of the injected signal. Simulation results indicate that the fault section can be accurately identified and that the disclosed protection method performs efficiently against transition resistance and noise.