275 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 method and apparatus is disclosed for monitoring the performance of a solar powered electrical supply where the supply comprises an array of photovoltaic cells that are mounted on a building. In one embodiment, the apparatus comprises: a device for producing a signal representative of solar irradiance; circuitry for computing a running performance signal by using at least the irradiance signal and a measure of the electrical power supplied to the load from the array; a radio for broadcasting the performance signal; and a portable unit for receiving the performance signal from the radio and for visually displaying the performance signal, power production, and electrical utility usage.

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.

A system and method for selectively connecting photovoltaic (PV) arrays of a PV power system in series and parallel arrangements is disclosed. A DC-to-AC power inverter in the PV power system is electrically coupled to a plurality of PV arrays to receive a DC output therefrom and invert the DC output to an AC output, with the DC-to-AC power inverter including a DC link that receives the DC output from the plurality of PV arrays. A contactor arrangement is positioned between the plurality of PV arrays and the DC-to-AC power inverter, with the contactor arrangement including a plurality of contactors that are switchable between an on state and an off state to selectively connect the plurality of PV arrays to the DC-to-AC power inverter in a specified arrangement, so as to control a level of DC voltage received by the DC-to-AC power inverter from the plurality of PV arrays.

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 embodiment of the invention discloses a short-circuit current calculation method and system, and the method comprises the following steps: S01, forming a basic database according to an actual power grid, and building a model of a set power grid operation mode; s02, scanning the short-circuit current level of the whole network; s03, solving each sequence impedance reduced to the short-circuit point by using a Newton method in combination with an iterative method, and solving the total current of the short-circuit point; s04, superposing the positive sequence component, the negative sequencecomponent and the zero sequence component of the total current of the short-circuit point to obtain a final short-circuit current; an inverter circuit, a control system and a boosting transformer control circuit are utilized. The positive sequence component, the negative sequence component and the zero sequence component can be superposed to obtain voltage and current of each phase; a set value of the internal potential of the inverter type photovoltaic power supply is generated through the step-up transformer control circuit recursive function, an overall mathematical model of a line power grid is established, the calculation amount is reduced, the calculation speed is increased, the calculation time is shortened, the operation efficiency is improved, the power supply safety can be improved, and the power grid can flexibly operate.

The invention relates to a photovoltaic power generation and urban power grid parallel power supply switching device which solves the problems of the existing device that the existing device is complex in structure, high in cost and poor in backflow-prevention performance during parallel power supply and a photovoltaic power supply cannot output the maximum power constantly. The photovoltaic power generation and urban power grid parallel power supply switching device comprises an alternating-current switching unit, a power supply unit, a control unit, a driving circuit, a sampling regulation unit and the like. The alternating-current switching unit is subjected to logic switching control by aid of the pulse width modulation strategy and the digital signal processor (DSP) software phase lock technology. The photovoltaic power generation and urban power grid parallel power supply switching device provides good guarantee for achievement of backflow-free photovoltaic power generation and urban power grid parallel power supply.

The invention relates to a solar chimney power generation system combining the photovoltaic technology, comprising a solar chimney and a solar thermal collector, wherein, the ceiling of the solar thermal collector is stuck with a thin film solar PV panel; or the bottom surface of the solar thermal collector is paved with the solar panel. The thin film solar PV panel stuck on the ceiling of the solar thermal collector is non-light tight. The solar panel paved on the bottom surface of the solar thermal collector is an ordinary monocrystalline silicon solar PV panel. The system can take full advantage of the light energy and the heat energy of the solar energy, after the solar panel converts the light energy of the solar energy into the electrical energy, the remaining solar energy is used for heating the air entering the solar thermal collector in the form of heat energy; the PV panel can be cooled perfectly to guarantee the efficiency and the generated output of the PV power generation system; the system raises the rate of utilization of the solar chimney power generation system on the solar energy and raises the generating efficiency of the solar chimney power generation system by about 30 percents.

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.

This invention comprises a DC motor driving circuit for use with a solar powered heating system and other applications such as solar powered irrigation or pumping. The circuit, in addition to functioning as a DC-to-DC converter between a photovoltaic (PV) power source and a motor, also contains a short term energy storage capability that is used to provide a jolt of current to a stopped motor. The circuit is designed to maximize motor runtime, and to be applicable to the varying internal resistances and pumping loads of a variety of motors.

The invention discloses a reactive power control method for a low-voltage power distribution transformer district with distributed photovoltaics. A distributed photovoltaic power supply, a photovoltaic inverter and a capacitor are arranged in the low-voltage power distribution transformer district. The reactive power control method comprises the following process of (S1) dividing a reactive powercontrol interval according to the voltage and power factor range of the transformer district, (S2) collecting low-voltage side voltage and power factors in the low-voltage power distribution transformer district, determining the reactive power control interval of a current transformer district according to the range of the voltage and the power factors and adjusting the reactive output of the photovoltaic inverter and the capacitor according to a control strategy corresponding to the reactive power control interval to achieve the reactive power adjustment of the low-voltage power distributiontransformer district. The operation interval of the transformer district is divided according to the voltage and power factors of the transformer district, the equipment such as a capacitor, an SVG and a photovoltaic inverter in the transformer district is controlled in real time according to a control strategy, and the reasonable scheduling of the transformer district voltage and power factors isensured.

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 embodiment of the invention discloses a distribution network collaborative optimization scheduling method considering distributed photovoltaic and electric vehicles. The method comprises the stepsof obtaining photovoltaic and vehicle data of a distribution network; making load flow calculation on a power distribution network, and determining the optimal load flow of the power distribution network and the load of each node when V2G is included; establishing a probability output model of the distributed photovoltaic power supply, and analyzing distributed photovoltaic expected output in different time periods; establishing a power generation side scheduling model taking the minimum power generation cost as a target function, and performing power supply joint optimization; establishing aload side optimal scheduling model integrating the peak-valley difference and the network loss, and solving the load side optimal scheduling model by adopting an improved particle swarm algorithm; and updating the load parameters in real time by adopting a load side optimal scheduling model integrating the peak-valley difference and the network loss and taking the minimum peak-valley difference and the minimum network loss as an optimization target. The technical problems that disordered electric vehicle charging and discharging enable the load peak-valley difference of the power distributionnetwork to be increased, the network loss of the power distribution network is increased, and the economy is reduced are solved.

The invention provides a universal power supply station integrated skill training device, and relates to the field of the power training service. At present, few faults are simulated by products, thepractical training scope of knowledge of students is relatively narrow, and the working efficiency is not improved. The universal power supply station integrated skill training device comprises a simulation practical training cabinet; the front side of the cabinet is provided with a first practical training simulation unit which is integrated with debugging and installation of an intelligent totalprotector, electric leakage checking, and line loss abnormity checking; the back side of the cabinet is provided with a second practical training simulation unit which is integrated with distributedphotovoltaic power supply grid-connection practical training and power utilization information acquisition; and the first practical training simulation unit is provided with two electric leakage faultsimulation circuits. According to the technical scheme, by integrating the first practical training simulation unit and the second practical training simulation unit on the same device, practical training and simulation of the power distribution network operation check skill and the power marketing skill are achieved conveniently, and teaching, training and examining of students in power technical schools, power supply company training centers, universal power supply stations and the like can be achieved comprehensively and quickly.

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 discloses a photovoltaic power structure and a maximum power tracking control method. The photovoltaic power structure comprises a photovoltaic assembly, BOOST circuits and a maximum power tracking control unit. An A output terminal and a B output terminal of the photovoltaic assembly are connected with the BOOST circuits respectively. Output terminals of the two BOOST circuits are connected in series and then are connected in parallel with a capacitor. A backward stage of the capacitor is grid-connected through a grid-connected system. The maximum power control unit compares output voltages of the two BOOST circuits. A difference value is converted into a corresponding duty ratio through a PI regulator. Then the duty ratio is converted into a corresponding PWM wave so that output power of the photovoltaic assembly is dynamically adjusted. And finally the photovoltaic assembly works stably at a maximum power point. By using the method, control is simple; a current sensor, memory and a microprocessor are not needed; only a simple circuit is needed so that maximum power tracking can be realized; cost can be greatly reduced.

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 present disclosure relates to a charge power control apparatus, a charge power control method, a program, and a solar power generation system, for improving charge efficiency. A solar power generation system includes a solar panel that receives sunlight to generate power, a PV power conditioner that performs DC / AC conversion of the power generated by the solar panel, and a charging AC / DC converter that performs AC / DC conversion of power output from the PV power conditioner and charges a storage battery. Voltage of the power supplied to the PV power conditioner from the solar panel is acquired while the power supplied from a power system is stopped, and a change in power supplied to the PV power conditioner from the solar panel is obtained according to the voltage. Charge power that is output from the charging AC / DC converter to charge the storage battery is adjusted based on the change in voltage.

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 present invention provides a photovoltaic power station remote monitoring system, comprising a monitoring center system and at least one monitoring terminal system; each monitoring terminal system is used for collecting operating parameters of a photovoltaic power station to which it belongs, and sending the operating parameters to the monitoring center system via a telecommunication network; the monitoring center system is used for receiving and displaying the operating parameters sent from respective monitoring terminal systems. For the monitoring personnel, a remote monitoring of respective PV power stations may be achieved only at the monitoring center system, which facilitates the monitoring.