38results about How to "Improve on-grid performance" patented technology

The invention relates to a wind collecting vertical type wind power generating system which comprises a wind power system, a vertical type speed increaser, a vertical type generator and an excitation grid-connected control system, wherein the wind power system is connected with the speed increaser and the generator by a chain coupling; the generator is controlled by the excitation grid-connected control system; the wind power system is in a box frame structure and comprises a fan blade system and a wind collecting and protecting system; the upper end and the lower end of a box frame are respectively provided with an upper shed top and a lower shed plate; the wind collecting and protecting system comprises a plurality of wind collecting plates which are distributed at four sides of the box frame and hydraulic drive equipment; the upper shed top, the lower shed plate and the wind collecting plates are connected to form a wind tunnel box type wind collecting body; the generator works in a multi-winding pole-changing control way; and the generator and the speed increaser are installed on the ground. The invention has the advantages of small size, low installation, maintenance and transportation cost, high wind power utilization ratio and wind field land utilization ratio, stable performance, high storm wind resistance and favorable power generating quality and grid-connected performance, can form a high-power wind power generator unit system and is suitable for various weather and geographic environments.

The invention provides an optimal dispatching method and system of a distributed photovoltaic cluster. The optimal dispatching method comprises the steps of calculating an optimal dispatching model, which is built in advance, by a master station to obtain a short-time scale optimal dispatching result, and issuing the short-time scale optimal dispatching result to a sub-station; receiving the short-time scale optimal dispatching result issued from the master station by the sub-station, and allocating the short-time scale optimal dispatching result to each photovoltaic field station; receiving an allocation result of the sub-station by the photovoltaic field station, and performing calculation to obtain a short-time scale dispatching instruction by combining the allocation result and each photovoltaic unit in the photovoltaic field station; and executing the short-time scale dispatching instruction by the photovoltaic unit to obtain an execution result. By the optimal dispatching method,the running cost and the circuit loss are reduced, and the distributed photovoltaic grid-connected capability and the control result are improved; and by the optimal dispatching method, the control dimensionality and the calculation complexity are effectively reduced, dispatching effectiveness and reliability are improved, a long-time scale optimal dispatching result is updated according to the short-time scale optimal dispatching result, and dispatching accuracy and effectiveness are improved.

The invention belongs to the technical field of wind power plants and discloses a wind power plant optimizing dispatching method for reducing mechanical loss of wind generating sets. The method includes the steps that firstly, numerical simulation is carried out under different wind conditions and different loading conditions to acquire the frequency of cyclic loading applied on different major parts under the different loading conditions; secondly, the cycle frequency generated when materials of the major parts are damaged under the different loading conditions is worked out, and then unit relative damage values of the major parts under the different loading conditions are acquired based on the linear cumulative damage theory; thirdly, optimizing calculation is carried out on combination and dispatching of wind generating sets in a wind power plant through the particle swarm optimization algorithm to obtain a combination of the wind generating sets in the wind power plant where mechanical damage of the major parts of the wind generating sets is smallest. According to the method, through reasonable combination and dispatching of the wind generating sets, output power is guaranteed, adverse effects of start, stop, switching and the like of the wind generating sets on the service life of the wind generating sets are reduced, and the operating cost of an electric system is reduced.

The invention provides a method for improving adaptability of distributed photovoltaics to an AC/DC hybrid microgrid. The method includes the steps of determining double closed loop control parametersof a distributed photovoltaic grid-connected system under a strong power grid condition, the double closed loop control parameters including a proportional control factor of a PI controller, an integral control factor of the PI controller and a capacitance current feedback factor; realizing virtual shunt impedance based on output impedance under a weak power grid condition; and determining valueranges of the parameters and shunt inductance of a phase lag link after system compensation. The method provided by the invention ensures that the system can stably run under the strong power grid condition, and at the same time, can satisfy requirements of a stable state and a transient state; and improves adaptability of the system to a weak power grid, i.e., through double closed loop parametersetting under the strong power grid condition, the method provided by the invention ensures grid connection performance under the strong power grid condition, and a method of lag link compensation and shunt inductance after adoption of virtual shunt impedance is employed to improve adaptability of the system to the weak power grid.

The invention provides a solar thermal generation and wind power generation complementary operation system. The system comprises a wind power generation subsystem, a wind power heat supply subsystem and a solar thermal generation subsystem, the wind power generation subsystem is used for converting wind energy to electric energy and sending the electric energy to a power grid or the wind power heat supply subsystem, the wind power heat supply subsystem is used for converting electric energy initiated by the wind power generation subsystem to heat energy and sending the heat energy to the solar thermal generation subsystem, and the solar thermal generation subsystem is used for converting the heat energy to electric energy and sending the electric energy to the power grid. Compared with the prior art, according to the solar thermal generation and wind power generation complementary operation system, the electric energy generated by wind power generation is stored by employing the heat storage capability of solar thermal generation, the controllability of the wind power is improved, the wind-power grid connection performance is enhanced, and fluctuation of the wind power can be suppressed.

The invention relates to a wind generating set. The wind generating set comprises an impeller (1), a main shaft (2), a gearbox (3), and a coupler (4), a generator (6) and a main machine frame (7) used as a supporting piece. The impeller (1) drives the main shaft (2) to rotate. The gearbox (3) is installed on a transmission chain of the main shaft (2) and is connected with the generator (6) through the coupler (4). The wind generating set further comprises a control device (50) and a speed rotation measuring device (9). An inner gear ring of a gear transmission mechanism in the gearbox (3) is connected with the control device (50) through an auxiliary transmission device. When the rotation speed measuring device (9) detects that the rotation speed of the main shaft (2) changes, the control device (50) controls the inner gear ring of the gear transmission mechanism to change the rotation speed and/or the rotation direction according to the change of the rotation speed of a sun gear in the gear transmission mechanism through the auxiliary transmission device, so that the transmission ratio of the gear transmission mechanism is adjusted; in this way, the application area of a draught fan is expanded, and the overall cost of the wind generating set is reduced.

The invention particularly relates to a frequency control method considering the kinetic energy throughput capacity of a doubly-fed fan. Frequency control is carried out when frequency deviation is positive and negative; when the frequency deviation is positive, redundant active power is absorbed from a power grid and stored in a fan, so active power redundancy of the system is reduced; when the frequency deviation is negative, kinetic energy is effectively released into the power grid from a rotating part of the fan, and the active power shortage of the system is compensated; therefore, active frequency control of the doubly-fed wind generating set is realized, frequency stability is improved, and the response time is provided for a synchronous generator to participate in system frequencymodulation. Different frequency control parameters are adopted to provide system frequency support capability; the proposed frequency control parameters can make full use of the capacity of the fan for storing and releasing the rotational kinetic energy to perform frequency control; when the frequency deviation is negative, the proposed control parameters can prevent the fan from stalling; and when the frequency deviation is positive, the provided control parameters can avoid excessive starting pitch angle control, and a problem of mechanical fatigue of the fan is reduced.

The invention provides a hydraulic wind power generation device. The wind power generation device is provided with a control module and an energy storage device capable of storing energy through a high pressure working medium; two or more energy storage pumps are driven by fan blades of the wind generation device through a gearbox; when the working medium is oil, the energy storage pumps are hydraulic pumps, and when the hydraulic pumps are driven, the oil in an oil tank is pumped into the energy storage device to form high pressure oil for energy storage; the hydraulic pumps comprises a largedischarge capacity hydraulic pump and a small discharge capacity hydraulic pump; clutchs capable of enabling the hydraulic pumps to be disconnected with the fan blades are connected to all the hydraulic pumps; and the control module controls the number and the discharge capacity of the hydraulic pumps driven by the fan blades through the clutches according to the current wind speed, so that the wind speed cut-in and cut-out range of a fan of the wind power generation device is enlarged. According to the wind power generation device, the wind speed cut-out and cut-in range can be enlarged, theinstallation is convenient, and the power output is stable.

The invention discloses a grid-connected control method of a single-phase photovoltaic grid-connected system, and relates to the technical field of power generation equipment manufacturing. A reference voltage and a network voltage are input from the input end of a PI control module, and a grid-connected current reference amplitude is output from the output end of the PI control module after PI calculation; a sampling voltage obtained from a photovoltaic cell is multiplied with the phase angle of a phase-locked loop in the phase-locked loop to obtain a grid-connected inverter reference current, the current reference amplitude, the grid-connected inverter reference current and the inverter sampling current are input to a current hysteresis control module respectively, the grid-connected inverter reference current and the inverter sampling current perform difference calculation in the current hysteresis control module, an error measurement value controls the output of an inverter through a PWM generator, the output of the inverter becomes stable sine-wave current output after filtering of a filtration module to be grid-connected, and the network voltage is obtained from the output end of the filtration module. The grid-connected control method can solve the problem that an existing grid-connected control technology is complicated in control process and poor in grid-connected effect.

The invention discloses an inverter model prediction control large signal stability method based on a Lyapunov criterion. Comprising the following steps: performing Clark coordinate conversion on three-phase grid-connected voltage and three-phase grid-connected current of a grid-connected inverter to obtain a voltage component and a current component at an initial moment k under an alpha-beta coordinate; acquiring corresponding actual voltage vectors of the grid-connected inverter in different switching states within the sampling period at a set time interval; calculating a virtual voltage vector by using the actual voltage vector; forming a standby voltage vector set by using the virtual voltage vector and the actual voltage vector; calculating a predicted current value at the (k + 1) moment through the voltage component and the current component at the initial moment k and the voltage vector in the standby voltage vector set; inputting the predicted current value into a Lyaponov control function, and judging whether the predicted current value meets a stability requirement or not; and controlling the grid-connected inverter to be in the optimal on-off state. The system stability can be ensured, the current quality can be improved, and the grid-connected performance is improved.

The invention relates to the technical field of wind driven generators, in particular to an active output fluctuation stabilizing method based on an operating working condition of a wind driven generator. The invention provides the active output fluctuation stabilizing method based on the operating working condition of the wind driven generator. The method stabilizes power at high frequency deviation and at low frequency deviation, that is, the method comprises the steps of storing energy effectively by means of a rotating part of a fan to inhibit active output fluctuation at high frequency deviation and releasing energy to a power grid effectively by means of the rotating part of the fan to inhibit the active output fluctuation at low frequency deviation, so that a double-fed wind drivengenerator unit takes part in power stabilization actively to smooth the frequency fluctuation of the system, thereby reducing the starting number of times of primary frequency modulation of a synchronous generator.

The invention discloses a virtual synchronous machine control method and system for a double-wind-wheel wind turbine generator set, and belongs to the technical field of wind turbine generator set control. Flexible adjustment of active power/reactive power of the unit is realized through coordinated control of two machine sides of the double-wind-wheel unit, so that the grid connection performance of the wind turbine unit can be improved on the basis of improving the operation efficiency of the wind turbine unit, and indifference control of the active power and the reactive power is realized; and when the amplitude and the frequency of a power grid are abnormal, inertia and one-time adjusting functions can be provided; the wind turbine unit realizes frequency response and voltage response through active/reactive power adjustment, and has the functions of inertia response, damping control and the like, so that the dynamic stability of a power system is further improved; and meanwhile, the coordinated output characteristic of the two wind wheel sets is fully utilized, the control logic is simple, and implementation is easy.

The invention relates to a damping coefficient quantitative identification method and system for a virtual synchronous generator. The method comprises the steps of acquiring the voltages and the currents of the virtual synchronous generator before and after a frequency change; and calculating the damping coefficient of the virtual synchronous generator according to the voltages and the currents ofthe virtual synchronous generator before and after the frequency change and based on a pre-established damping coefficient quantitative identification expression. The method enables the correct quantitative identification of the set damping coefficient D.

The invention discloses a guyed tower type wind-driven water pumping and energy storing generation system, which comprises an upper reservoir, a lower reservoir, a guyed tower provided with a wind-driven generator, and a machine room placed between the upper reservoir and the lower reservoir, wherein a hydraulic generator and an electric water pump are arranged in the machine room; a water inlet of the hydraulic generator is connected to the upper reservoir through a water pipeline at the bottom of a dam, and a water outlet of that is connected to the lower reservoir; a water inlet of the electric water pump is connected into the lower reservoir, and a draining pipe of that is connected into the upper reservoir; the hydraulic generator can generate through the water in the upper reservoir; the water in the lower reservoir is pumped into the upper reservoir by the electric water pump through the power produced by the hydraulic generator. The power station with the generation system disclosed by the invention has good performance on peak regulating and synchronization; the generation system can directly replace thermal power and other fossil energy to generate power without power grid adjusting, so the generation system is a novel wind-driven generation system achieving the purpose of replacing fossil energy to generate power.

The invention relates to the technical field of wind driven generator frequency control, in particular to a controllable short-term frequency supporting method for a wind driven generator suitable forlow-frequency disturbance. According to the method, droop control is added to fan rotor side control, and the active loss of a system is compensated by temporarily releasing the rotational kinetic energy stored in a fan; a self-defined droop parameter is calculated by considering the participation frequency modulation potential of the fan; rapid system frequency response is actively provided; thesystem frequency support control of a controllable wind turbine generator is realized under different fan operation conditions; that is to say, when the rotating speed of a fan rotor is high, rotating kinetic energy is fully released to compensate for active power loss and provide response time for a conventional generator set to participate in regulation, and when the rotating speed of the rotoris low, a proper amount of rotating kinetic energy is released to compensate for system active power loss, and the fan rotating speed instability problem and severe secondary frequency drop are not caused. A guarantee is provided for high-wind-power grid connection, and the use of an energy storage device for frequency modulation is reduced; and commercial development of the fan can be promoted.