85results about How to "Smoothing fluctuations" patented technology

A renewable energy generator imposes costs on a power grid from rapid fluctuations in output. A device is disclosed that collects data on renewable power production, meteorological and other information, forecasts short timescale renewable power production then mitigates costs incurred by power fluctuations by modulating the power output, while maximizing power production revenue. Mitigation may be effected by an AC / DC inverter, an energy storage system, demand response or a FACTS device. The magnitude and costs for modulating response required from energy storage, FACTS or other power modulation equipment is thereby reduced.

A power control interface between an unstable power source such as a wind farm and a power transmission line employs an electrical energy storage, control system, and electronic compensation module which act together like an "electronic shock absorber" for storing excess power during periods of increased power generation and releasing stored energy during periods of decreased power generation due to wind fluctuations. The control system is provided with a "look ahead" capability for predicting power output (wind speed conditions) and maintaining energy storage or release over a "narrow-band" range despite short duration fluctuations. The control system uses data derived from monitoring the wind farm power output and the power transmission line, and employs system-modeling algorithms to predict narrow-band wind speed conditions. The power control interface can also use its energy storage capacity to provide voltage support at the point of injection into the power transmission system, as well as fault clearance capability for "riding out" transient fault conditions occurring on the power transmission line.

The invention discloses a capacity optimization configuration method for a hybrid energy storage system orientating optimization operation of a power distribution network. The capacity optimization configuration method comprises the steps of obtaining imbalance power between the optimal output and photovoltaic actual output when an optical storage system participates in operation of the power distribution network firstly, taking the imbalance power as a hybrid energy storage reference power, adopting ensemble empirical mode decomposition to decompose the imbalance power into a series of intrinsic mode functions, and performing recursion Hilbert conversion to obtain an instantaneous frequency-time curve of each intrinsic mode function separately; according to power type and energy type energy storage characteristics, determining crossover frequency by taking least aliasing of the instantaneous frequency-time curves as a principle, and stabilizing the high-frequency components and low-frequency components of the imbalance power by adopting power type energy storage and energy type energy storage respectively; and finally, by considering charging-discharging efficiency, state of charge and life cycle cost, a power type and energy type energy storage rate power and rate capacity economic optimal configuration scheme is proposed. Compared with a conventional method, new energy output can be compensated, consumption capability to new energy can be improved, and active participation to the optimization operation of the power distribution network can be realized.

The invention discloses a semi-physical real-time simulation platform for a wind generating set and belongs to the technical field of clean energy. The simulation platform is mainly composed of an upper computer monitoring interface, a wind generating set simulation system, a controller simulation system, a current transformer controller and a variable pitch system. An upper computer is respectively connected with the wind generating set simulation system and the controller simulation system through Ethernet. The simulation platform can quickly develop and verify a control algorithm, can simulate operation characteristics of a real wind generating set, enables a controller to carry out comprehensive loop test before true machine set test, saves test cost, improves operation safety, can control the output power of a fan, stabilizes power grid fluctuation and provides a basic research platform for optimal operation of a wind power plant.

A linear actuator with a high holding force providing good irreversibility, has a high efficiency, low friction screw mechanism and a stepper motor with high magnetic detent torque but a low output torque ripple. The phase torque is modified to minimize the effect of the detent torque on the output. torque. Preferably, the motor has asymmetric phases to compensate for the detent torque.

The invention discloses an air separation oxygen generating device for energy accumulating and releasing. The device is characterized in that an air separation oxygen generating device and a nitrogenexpansion power generating device are included, oxygen products are stably output in the long term through an air separation variable loading technology and a liquid nitrogen energy accumulating technology, and electricity is output at a peak power consumption period. The device has the advantages that the whole process continuous operating of an energy accumulating device (air separation device)is achieved to effectively reduce debugging consumption and faulty risks due to frequent on and off of equipment, high-value oxygen products can be obtained while an energy accumulating power generating function can be achieved, and the technology is an efficient and economical energy accumulating technology.

In an electric power steering apparatus of the invention, a control circuit determines a command value of drive voltage supplied to a motor drive circuit based on an actual current through a motor and a target current. When the command value exceeds the previous value having a lower limit equivalent to a limit value representing the limit of the power supply from a battery, the control circuit controls the amount of discharge from the auxiliary power supply according to a difference between the command value and the previous value by increasing or decreasing a duty of switching devices. Thus, the power steering apparatus can save the energy of the auxiliary power supply for efficiently using the auxiliary power supply.

The method of controlling a battery storing electric power generated by a power generator generating electric power using renewable energy comprises detecting an amount of electric power generated by the power generator at a first time and a second time that is prior to the first time; computing a rate of increase or decrease of the amount of electric power between the first time and the second time; computing a target output value for the electric power to be supplied to an electric power transmission system based on the rate, and supplying to the electric power transmission system electric power corresponding to the target output value from at least one of the power generator and the battery.

The potential of a smoothing capacitor for a speaker is smoothly changed by controlling the potential with use of a PWM signal and switching between outputting the PWM signal and an actual audio signal, thereby suppressing a pop sound. The scale of circuitry is reduced and cost is lowered by implementing a PWM circuit in a one-chip microcontroller. Noise is eliminated by outputting a pulse that has been divided in the PWM signal generation stage.

A power quality promotion method of a light storage power generation system based on hierarchical control provided by the invention comprises the following steps: a, constructing a light storage combined power generation system, wherein the constructed light storage combined power generation system comprises a hybrid energy storage unit arranged on the direct current side of a distributed photovoltaic power generation system; and b, carrying out active management on power quality through power dispatcher control and local power of the light storage combined power generation system. The distributed light storage combined power generation system can effectively stabilize the fluctuation of photovoltaic output power, and strengthens the schedulability of the light storage combined power generation system; and a harmonic current detecting algorithm based on self-adaptive iteration can effectively detect the harmonic component of local load, and provides guarantee for local compensation of the power quality of the distributed light storage combined power generation system. The invention provides a new method for operation and control of the high-permeability photovoltaic power generation system, can effectively promote the power quality of power grid, and provides powerful guarantee for safe and stable operation of the power grid.

The invention relates to a method for operating an electronically commutated motor (10) that comprises a rotor (12), a stator (14) having a multi-strand winding arrangement (16) for whose energization a power stage (18) is provided, a first lead (30) and a second lead (32) for connecting the power stage (18) to a voltage source (24), and a first controller. A first signal (U_34; U_38) is sensed, which signal characterizes a current (I_IN; I_IN′; I_M; I_M′) flowing through at least one of the leads (30; 32); the first controller generates at least one clocked signal (PWM) and outputs it to the power stage (18) in order to influence the first value, permitted current. The invention also relates to a corresponding motor (10).

The invention discloses a random production simulation method taking participation of various power supplies in peak load regulation and application thereof. The random production simulation method comprises the following steps: 1) acquiring an annual load curve; 2) removing annular output of wind power, photovoltaic power and nuclear power from the annular load curve to obtain a continuous load curve, and partitioning the continuous load curve into a base load, a shoulder load and a peak load according to an annual load level; 3) building an equivalent electric quantity function according tothe continuous load curve; and 4) realizing output of a thermal power unit and a hydropower unit at different stages according to the equivalent electric quantity of the base load, shoulder load and peak load to obtain random production simulation data of a power system. Compared with the prior art, the random production simulation method has the advantage of improving the peak load regulation capability of a regional power grid.

The invention discloses a photovoltaic power stable output control method based on an energy storage operation state. The method comprises the steps that S1 the research object time window length y and the running data P(t) are selected; S2 an expected output target value PG is determined based on an optimal power output model; S3 the particle swarm dimension D, the maximum number of iterations Mmax and the convergence accuracy C sigma are set, and at the same time the particle group position x and the velocity v are initialized; S4 according to a charge and discharge strategy, the fitness value pxid of each particle is calculated; the particle extremum pi and the global particle extremum pg are compared; if the fitness value is small, pi and pg are updated, otherwise the particle velocity Vid and the position Xid are updated; and S5 delta sigma 2 is calculated; whether a convergence condition described in the description is satisfied is determined; if so, the best storage capacity WO is acquired; if not, particles are re-released to set up a new group, and the step S4 is repeated. According to the invention, the grid-connection power fluctuation can be effectively stabilized, and at the same time the charging state of an energy storage system can be accurately adjusted.

The invention discloses a system and method for controlling the power of a micro-grid grid-connected tie line. The method comprises the steps that: a micro-grid central controller collects electricalquantities of a micro-grid and a tie line; the relationship between a protocol power PAgr and a micro-grid net load Pnet is judged, the predicted value of the protocol power PAgr is given by an energymanagement system, if the energy management system does not give a value, the value of the protocol power Pagr is an average value of the micro-grid net load Pnet in the time Delta t, when Pagr is larger than Pnet, the micro-grid central controller issues a command to a battery management system to adjust the output of an energy storage unit, the output value of the energy storage unit is PB=Pagr-Pnet, when Pagr is smaller than or equal to PNet, the micro-grid central controller issues a command to the battery management system to stop the output of the energy storage unit, and the charging of the energy storage unit is started. The system and method have the advantages of quick response, simple scheme and good stability.

The invention relates to the technical field of the combined power supply and particularly relates to a flywheel energy storage device, a generator set combined power supply system and a control method. The system comprises a generator set, a rectifier, an impact load and a flywheel energy storage device. A general controller in the flywheel energy storage device automatically generates a charge and discharge control command according to acquired and processed data information and sends the command to each flywheel controller to control the charge and discharge states of the flywheel energy storage unit to maintain stable operation of the entire system, due to the advantages of fast charging and discharging response speed, long service life and good safety of the flywheel energy storage device, the system and the control method of the invention suppress the fluctuation of the impact load through the flywheel energy storage device, the stability and reliability of the working of the generator set are improved, the service life of the generator set is prolonged, the capacity and energy consumption of the generator set are reduced, and therefore, the cost of the power supply system isreduced.

In an electric power steering apparatus of the invention, a control circuit determines a command value of drive voltage supplied to a motor drive circuit based on an actual current through a motor and a target current. When the command value exceeds the previous value having a lower limit equivalent to a limit value representing the limit of the power supply from a battery, the control circuit controls the amount of discharge from the auxiliary power supply according to a difference between the command value and the previous value by increasing or decreasing a duty of switching devices. Thus, the power steering apparatus can save the energy of the auxiliary power supply for efficiently using the auxiliary power supply.

The invention discloses a preparation method for modified barium titanate ceramics suitable for a super capacitor, wherein the preparation method comprises the following steps: step a, auxiliary material preparation: selecting SnO2, CaCO3, BaCO3 and TiO2 and mixing evenly in proportion to obtain an auxiliary material mixture, putting the auxiliary material mixture in a muffle furnace, sintering for a first time, taking out the material, and crushing the material to obtain an auxiliary material, wherein the granularity of the auxiliary material is 3-5 [mu]m; step b, raw material preparation: selecting BaCO3 and TiO2 and mixing, then putting the mixture into the muffle furnace, sintering for a second time, and crushing the product after sintering to obtain a fine powder material; and step c, raw material modification: selecting the auxiliary material and the fine powder material and mixing, putting the mixture into the muffle furnace, sintering for a third time, and crushing the product after sintering for the third time to obtain a finished product. The method has the beneficial effects that the process is simple, the cost is saved, fluctuation of the dielectric coefficient is smooth along with temperature variation, the granularity is relatively fine, and the stable composite material is convenient to synthesize.

The invention discloses an inverted hanging type wave energy generation device and an optimal capturing method thereof. Wave energy is captured through a cylinder floater. A rotor of a linear motor isdriven by a crank connecting rod and a change wheel in a speed raising mode so as to generate electricity, and the wave energy capture power is adjusted by means of an uncontrollable rectifier and aBOOST converter. Wave energy capturing is improved by adopting the collaborative optimal capturing method including capturing control stabilization optimization and capturing control disturbance optimization. Wave energy feature extraction is achieved based on omnibearing collection of sixteen buoys internally comprising accelerometers and gyroscopes. Capturing control stabilization optimization is achieved on the basis of collaborative optimization of a cylinder floater dynamic model and effective output power of a linear generator. Capturing control disturbance optimization is achieved by disturbance adjustment of parameters of a controller based on steady-state optimization of the controller in combination with on-line optimization of the output power of the generator. The inverted hanging type installing and optimal capturing method greatly lowers the sealing and corrosion prevention requirements of equipment, and greatly improves wave energy capturing power.

In a method for measuring the speed of an electrical machine having a stator, a rotor and a winding, in particular of an electronically commutated motor, a speed-measurement signal ω is sampled, in that a measured speed value ω(k) for the rotor is determined for each of a series of sampling instants. Moreover, a moment of inertia value for the mass moment of inertia of the rotor is determined. In addition, a current signal I is sampled, in that a current value I(k) for the electrical current in the winding is determined for each of the sampling instants. An estimated value ωs(k) for each of the measured speed values ω(k) is determined from a measured speed value ωk(k−1) assigned to an earlier sampling instant, from the current signal I and from the moment of inertia value. A tolerance band containing the estimated value ωs(k) is assigned to this estimated value ωs(k). If the measured speed value ω(k) lies outside of the tolerance band, the measured speed value ω(k) is replaced by a speed value ωk(k) that is within the tolerance band.

A method for optimizing the operation of a distribution network jointly connected with an soft normally open point (SNOP)and an energy storage device, comprises the following steps of: a, establishinga distribution network model jointly connected to the SNOP and the energy storage device by using back-to-back VSCs and a battery; b, establishing a distribution network daily dynamic optimization model based on the SNOP and the energy storage device; c, solving the optimization model by using a genetic algorithm to obtain control reference values including the active power PI flowing through the VSC on a feeder line I side, the active power PJ flowing through the VSC on a feeder line J side, the reactive power QI of the VSC on the feeder line I side, and the reactive power QJ of the VSC onthe feeder line J side, and giving a two-step correction strategy to improve the service life of the energy storage device and the absorption level of uncontrollable distributed power supply. The method combines the SNOP and the energy storage device to form a highly integrated intelligent distribution network comprehensive regulation and optimization device, further strengthens the scheduling control capability of the SNOP, provides the SNOP with a power transmission function and an energy storage function, can suppress fluctuations caused by new energy connection and improves the absorptioncapacity of distributed power source.

The invention relates to a method for operating an electronically commutated motor (10) that comprises a rotor (12), a stator (14) having a multi-strand winding arrangement (16) for whose energization a power stage (18) is provided, a first lead (30) and a second lead (32) for connecting the power stage (18) to a voltage source (24), and a first controller. A first signal (U—34; U—38) is sensed, which signal characterizes a current (I_IN; I_IN′; I_M; I_M′) flowing through at least one of the leads (30; 32); the first controller generates at least one clocked signal (PWM) and outputs it to the power stage (18) in order to influence the first value, permitted current. The invention also relates to a corresponding motor (10).

The invention discloses high-temperature waste gas purification equipment, which structurally comprises a discharge cavity, a fan, an inlet and outlet, a removal device, a purification cavity and a machine body. When the high-temperature waste gas purification equipment is used, impurity dust in waste gas is treated through a rubber arc block and a patch auxiliary fine filter screen, the waste gas subjected to primary treatment is efficiently treated through a plurality of layers of adsorption separation nets, dust impurities in waste gas are effectively treated, so that dust is not prone to adhering to the interior of equipment, sulfur dioxide in the waste gas is efficiently adsorbed through cooperation of the reaction film and the molecular sieve layer, sulfur dioxide in the waste gas can be effectively removed, and the waste gas treatment effect is improved.

The invention provides a composite energy storage power supply system for peak regulation and frequency modulation of a power grid. The system comprises a renewable energy power generation device; a battery energy storage device, wherein a first input end of the battery energy storage device is connected with a power supply output end of the renewable energy power generation device through a DC / DC converter; a first DC / AC converter, wherein the power supply output end of the battery energy storage device is connected with the common alternating current bus through the first DC / AC converter; a second DC / AC converter, wherein the power supply output end of the renewable energy power generation device is connected with the common alternating current bus through the second DC / AC converter; a solar thermal power generation device, wherein the power supply output end of the solar thermal power generation device is connected with the public alternating current bus through an AC / AC converter; and a heat storage device which is connected with the solar thermal power generation device, wherein heat storage and heat release can be carried out between the heat storage device and the solar thermal power generation device. The composite energy storage power supply system provided by the invention can give consideration to stability, reliability, economy and environmental protection when being used for peak regulation and frequency modulation of a power grid.

The invention discloses a user-side micro-energy network energy supply system. The user-side micro-energy network energy supply system comprises a residential community micro-energy network, a commercial park micro-energy network, an industrial area micro-energy network and an agricultural area micro-energy network, wherein each of the residential community micro-energy network, the commercial park micro-energy network, the industrial area micro-energy network and the agricultural area micro-energy network comprises an input unit, an intermediate energy production, conversion and storage unitand an output unit; the input unit is connected with an external power grid, a municipal heat supply network and a natural gas network, is also connected with other micro-energy networks, and inputs electric energy and heat energy of the other micro-energy networks; the intermediate energy production, conversion and storage unit comprises a cold bus, a heat bus, an electric bus, an energy conversion device and an energy storage device; and the output unit outputs cold, heat and electricity to meet cold, heat and electricity requirements of users in the micro-energy networks, redundant electricity is connected to the networks or is supplied to the other micro-energy networks, and redundant heat energy is supplied to the other micro-energy networks. The user-side micro-energy network energysupply system can realize clean and efficient, energy-saving and environment-friendly gradient utilization, complementary coordination, safety and high quality of the whole process of energy production, transmission and utilization.

The method of controlling a battery storing electric power generated by a power generator generating electric power using renewable energy comprises detecting an amount of electric power generated by the power generator at a first time and a second time that is prior to the first time; computing a rate of increase or decrease of the amount of electric power between the first time and the second time; computing a target output value for the electric power to be supplied to an electric power transmission system based on the rate, and supplying to the electric power transmission system electric power corresponding to the target output value from at least one of the power generator and the battery.

The invention provides a DC power system power quality regulator. When harmonic currents appear on the DC bus of the DC power system, the hybrid DC power system power quality regulator can filter out the harmonic current in the DC bus. Or when harmonic voltage appears on the DC bus of the DC power system, the hybrid DC system power quality conditioner can filter out the DC bus harmonic voltage, smooth the DC bus voltage and current waveform, and realize the balance between the power supply side and the load side. Harmonic isolation, preventing harmonics from flowing in both directions between the two.

The invention discloses a wind-solar complementary hydrogen production power station system based on a + / -600V direct current microgrid. The system comprises a wind power generation module, a photovoltaic power generation module, an energy storage module and a water electrolysis hydrogen production module, the wind power generation module is connected with a + / -600V direct current bus through a wind power rectifier and serves as a new energy power generation end to supply power, the photovoltaic power generation module, the energy storage module and the water electrolysis hydrogen production module are connected with a + / -600V direct current bus through a direct current converter, and the + / -600V direct current bus is connected with an alternating current power grid through a grid-connected module to achieve grid-connected operation or isolated-grid operation of the direct current micro-grid hydrogen production system. The direct-current bus bar is adopted to greatly reduce the electric energy conversion link of the multi-energy complementary hydrogen production system, the reliability of the system and the comprehensive utilization efficiency of energy are improved, a direct-current micro-grid hydrogen production system topological structure suitable for multiple operation modes of grid connection and isolated grid is provided, the requirement for high-efficiency uninterrupted hydrogen production under various working conditions is met, and high-efficiency and low-cost production of hydrogen energy is realized.

The invention discloses a midpoint potential balance control method suitable for a VIENNA rectifier. The working principle of the VIENNA rectifier is analyzed, and the principle of space vector modulation is used to analyze a carrier phase shift modulation process, so as to determine the cause of midpoint potential imbalance. Finally, according to an area equivalence principle, high-frequency PWMXOR control pulse is used to decompose redundant and non-redundant vector components. A midpoint potential compensation coefficient D is set to adjust the decomposition ratio to ensure midpoint potential balance. Midpoint potential balance control of the VIENNA rectifier is realized. According to the invention, midpoint potential fluctuations are stabilized; the output voltage of the direct current side is stabilized; current distortion on the grid side is reduced; and the principles are simple and easy to implement.

A magnetization pattern of a rotor magnet for a stepping motor includes a plurality of magnetization portions, which is provided on the rotor magnet in a rotation direction of the rotor magnet. The magnetization portions have different magnetic poles which are alternately arranged. Some magnetization portions of the magnetization portions have respectively magnetization widths A. Said some magnetization portions are opposed each other with a rotary axis or the rotor magnet as a center among said some magnetization portions. The other magnetization portions of the magnetization portions have respectively uniform widths B. Each of the magnetization widths A is greater than that of the uniform widths B.