748results about How to "Frequency stability" patented technology

A product includes a power supply circuit board, which includes a power supply circuit having a stable frequency characteristic which enables communication among various products to be obtained. The product includes a power supply circuit board including a power supply circuit arranged thereon having an inductance element, and a wireless communication circuit board electrically connected to the power supply circuit. The wireless communication circuit board is mounted on the power supply circuit board. The product further includes a radiation plate which emits a transmission signal which is supplied from the power supply circuit through electromagnetic field coupling and which has a frequency substantially determined in accordance with a resonant frequency of the power supply circuit, and which is used to supply a reception signal to the power supply circuit through electromagnetic field coupling.

An electromagnetic-coupling module including a radio IC chip and a feeder circuit board on which the radio IC chip is mounted and a feeder circuit including a resonant circuit having a predetermined resonant frequency is attached to an article. The article has a radiation element that radiates a transmission signal supplied from the feeder circuit of the electromagnetic-coupling module via electromagnetic coupling and that supplies a received reception signal to the feeder circuit via the electromagnetic coupling.

A wireless IC device includes a wireless IC chip, a feed circuit board having the wireless IC chip mounted thereon and including a feed circuit including inductance elements, and a radiation plate electromagnetically coupled to the inductance elements in the feed circuit. A high-permeability magnetic body made of a high-permeability magnetic material is provided in the feed circuit board and a portion of the inductance elements is provided in the high-permeability magnetic body.

The present invention relates to a method and apparatus for using wind energy to compress air or pressurize a fluid as a means of storing energy. Compressed air or pressurized fluid is generated directly by the wind turbines, thereby avoiding the energy losses that occur when wind power is used first to generate electricity to run an electrically powered air compressor. The compressed air or pressurized fluid is stored by means of expanding a volume at constant or nearly constant pressure. This method avoids energy losses that would otherwise result from compressional heating; while also allowing lower pressures to be employed, reducing the cost of the containment facility and avoiding the need to locate facilities in geographically favored locations where underground storage is available. The invention permits both large and small-scale storage at low cost per unit of energy stored, thereby avoiding the difficulty of using a highly variable and unreliable source of energy such as the wind for electrical power generation. The invention can be used for generation and storage on land, in shallow near-shore waters and in deep-water locations far from shore.

A wireless IC device includes a flexible sheet provided with a wireless IC chip and radiation plates. The wireless IC chip is connected by an Au bump to a feeder circuit which is located on the sheet and which has a predetermined resonant frequency and a predetermined impedance. The feeder circuit includes electrode patterns, and the feeder circuit and the radiation plates are capacitively coupled with each other through the flexible sheet.

The invention relates to the technical field of photovoltaic micro-grid control, and particularly discloses a real-time coordination and control method of a photovoltaic micro-grid system. A central real-time optimal control layer and a local control layer are involved in the real-time coordination and control method. The central real-time optimal control layer collects the voltage and frequency of an AC bus of the photovoltaic micro-grid system, the charge state of a storage battery pack, the output power of photovoltaic power generation micro-sources, the output power of the storage battery pack, the output power of a super capacitor and the real-time power of a load in real time, generates a real-time coordination and control strategy and a secondary frequency modulation and scheduling plan, and issues the strategy and the plan to all local controllers. The local control layer coordinates and controls all the micro-sources in real time, and particularly achieves the scheduling plan issued by the central real-time optimal control layer. According to the real-time coordination and control method, a micro-grid central optimizing controller can manage, coordinate and control all the local controllers in a unified mode, the micro-grid can efficiently and economically run, the output power of the photovoltaic power generation unit is utilized to the maximum extent, the output power fluctuation and the tracking load change of the photovoltaic power generation unit are restrained, the running method of the micro-grid is reasonably adjusted, and energy balance is achieved.

The antenna device includes an electrical conductor extending on a substrate and having at least one gap therein, and with an outer ring portion to define a radiating antenna element, and at least one inner ring portion to define a feed coupler and connected in series with the outer ring portion and extending within the outer ring portion. A coupling feed element is adjacent the at least one inner ring portion, and a feed structure is connected to the coupling feed element to feed the outer ring portion. A plurality of inner ring portions may be provided with the coupling feed element being adjacent a selected one of the plurality of inner ring portions. The plurality of inner ring portions may have a common size and be symmetrically spaced within the outer ring portion. The radiation pattern may be sufficiently isotropic to eliminate the need for antenna aiming. An epicyclic geometry radiating element provides for a compound antenna design.

A power compensation apparatus for a renewable energy system includes a plurality of converter modules positioned between any two phases of a three-phase AC electrical grid, each converter module including a plurality of inverter circuits connected in series. Each inverter circuit includes an energy storage unit for providing a direct current (DC) voltage; a capacitor connected to the energy storage unit; and an H-bridge circuit converting the DC voltage into an alternating current (AC) voltage. The converter modules perform reactive power compensation and active power regulation on the electrical grid in a delta connection. A plurality of converter modules are respectively positioned between any two phases of the electrical grid in a delta connection, so as to keep the voltage of the electrical grid continuously stable when the voltage of the electrical grid fluctuates, and also compensate load current when system load is not balanced.

The invention provides a control method of a grid friendly type distributed power source based on hybrid energy storage. The method comprises the steps of optimally designing a topology structure of the distributed power source, controlling a direct current power supply system in a coordinating mode through a direct current (DC) / DC converter controlling a model normalization model, and self-adaptively controlling a grid of an alternating current (AC) side DC / AC converter. The distributed power source not only can be connected in a large grid to operate so as to reduce the influence of intermittent renewable energy power generation grid connection on the grid and provide support of voltage and frequency for the grid, but also can be connected into a micro-grid to operate as a network unit of the off-network type micro-grid to maintain stability of voltage and frequency of the off-network type micro-grid. When an outer grid breaks down, the distributed power source can realize switch between a grid mode and an island mode so as to improve power supply reliability of important loads in the system. The distributed power source improves technical performance and economic performance of the whole system through matching utilization of an energy type system and a power type energy storage system.

A wireless transmission system includes: a communication unit for transmission; and a communication unit for reception. The communication units for transmission and reception are housed in a housing of the same electronic apparatus, or the communication unit for transmission is housed in a housing of first electronic apparatus and the communication unit for reception is housed in a housing of second electronic apparatus and a wireless signal transmission path enabling wireless information transmission between the communication units is formed between the communication units when the first and the second electronic apparatus are disposed at given positions to be integrated with each other. The communication unit for transmission includes a first carrier signal generating unit and a first frequency converter, and the communication unit for reception includes a second carrier signal generating unit, and a second frequency converter.

The invention discloses a grid-connected non-networking micro-grid system and a control protection method thereof. On the premise of basically not changing the structure of the original power distribution system, multiple types of distributed power sources, such as wind power generation system, photovoltaic power generation system, cell accumulation system and the like, are connected into a common power grid along with user loads through AC buses, and reasonable load layout and active energy management are utilized to implement grid-connected non-networking of the micro-grid system. By using the structural design and the active energy management of the micro-grid central control unit, the new energy power generation system can be completely self-sufficient, and does not reversely transmit power to the common power grid, thereby avoiding impacting the normal power supply of the common power grid; and meanwhile, by the aid of the common power grid, the user loads have higher power supply reliability and electric power quality.

The invention provides an AC and DC mixed micro-grid system based on a power electronic transformer and a power control method of the system. The system comprises a main grid, an AC micro grid, a DC micro grid and the power electronic transformer. According to the operation states and power requirements of the AC micro grid and the DC micro grid, the power electronic transformer adjusts the power of the AC micro grid and the DC micro grid in a mixed sagging method. Thus, the power of the main grid, the AC micro grid and the DC micro grid can be rapidly and accurately adjusted, it is ensured that the frequency of the AC micro grid and the bus voltage of the DC micro grid are stable, and stable operation of the AC and DC mixed micro-grid after access of distributed energy is realized.

Method for stabilizing the frequency of a frequency synthesizer by means of a reference oscillator unit coupled to a voltage controlled oscillator (VCO) and a frequency synthesizer, wherein the synthesizer is provided with a phase locked loop (PLL) to stabilize the operation of the voltage controlled oscillator, wherein the reference oscillator unit is a MEMS (MicroElectromechanicalSystems) reference oscillator unit, the temperature of the MEMS reference oscillator unit is measured, and the output frequency is corrected according to the measured temperature by using a frequency / temperature function.

The invention provides a coordination control method capable of enabling a super-capacitor energy storage system to participate in electric power primary frequency modulation, wherein the super-capacitor energy storage system is arranged on the bus side of a generator set which needs cooperation. A decision optimizing module obtains a frequency from a synchronous vector measurement unit, and the frequency deviation is obtained through the difference between the frequency and a 50Hz frequency. If the deviation exceeds a frequency dead band, the same motion instructions are simultaneously sent to a traditional generator set and the super-capacitor energy storage system. When the super-capacitor energy storage system participates in primary frequency modulation, the opportunity motion and the motion depth of the super-capacitor energy storage system are determined through the decision optimizing module according to partition of typical working conditions, the conversion from the frequency deviation to the power is achieved through a power-frequency conversion module, the charging / discharging control of the super-capacitor energy storage system is achieved through a PCS control module, and finally the traditional generator set is assisted in participating in the primary frequency modulation process. According to the coordination control scheme, the transient state performance and the steady-state performance of the primary frequency modulation can be obviously improved, frequent starting of the traditional generator set is reduced, and the power system frequency can be rapidly kept stable.

The invention provides a composite energy storage system, which consists of a supercapacitor and a storage battery, wherein the composite energy storage formed by the supercapacitor and the storage battery has both power type and energy type characteristics; through the combined use, the charging and discharging times of the storage battery can be effectively reduced; in addition, the utilization rate of the energy storage system can be improved. According to an energy management and control optimization method matched with the composite energy storage, the total power of the composite energy storage is distributed through a low-pass filter, so that the supercapacitor and the storage battery respectively share a high-frequency component and a low-frequency component in the fluctuating power; through the two-way DC / DC1 converter constant-power control on the storage battery, the two-way DC / DC2 converter constant bus voltage control on the supercapacitor, and control strategies of the two-way DC / AC converter, the network loss of a power distribution network is reduced; the utilization efficiency of new energy sources is improved; the power fluctuation during micro power grid interconnection is effectively inhibited; the electric energy quality of a region electric network is improved; in an offline state, the stability of the voltage and the frequency of a micro power grid system can be ensured; the power balance generated during grid connection / off-grid switching is fast compensated.

The invention provides an on / off-grid control method for a microgrid with a plurality of distributed power supplies. When the microgrid is on on-grid operation, a central controller of the microgrid can continuously carry out isolated island detection. When the microgrid is detected to be in an isolated island operation state, isolated island operation control is carried out according to a preset strategy. When the microgrid is in an off-grid operation state, the central controller of the microgrid can start an on-grid process to achieve the positive sequence voltage amplitude of the large power grid side, the frequency of the large power grid side, the frequency of the microgrid side, the voltage of the large power grid side, the voltage of the microgrid side, the voltage phase angle value of the large power grid side and the voltage phase angle value of the microgrid side. Whether the microgrid is suitable for on-grid operation is judged by comparing the relationship between correlation values and preset values. If on yes judgment, the central controller of the microgrid can control the breakers to be switched on to achieve grid connection. The control method can achieve the on / off-grid control on the microgrid with distributed power supplies, avoids long-time off-grid operation of the mcirogrid and can timely break the mcirogrid to enable the microgrid to operate normally when a larger power grid is broken down.

A voltage controlled oscillator (VCO) includes a current source, a current sink and a frequency generator. The current source generates a first current having a first negative temperature coefficient. The current sink generates a second current. A current level of the second current varies in response to a first voltage level of a control voltage, and the second current has a second negative temperature coefficient. The frequency generator generates an oscillating signal having a frequency corresponding to a difference between the first and second currents. The VCO generates the oscillating signal having a stable frequency that is independent of temperature variation.

The invention discloses a method for preparing nano-rod cellulose, which comprises the following steps: dispersing fiber raw material into sulphuric acid water solution of which mass concentration is 50 to 65 percent, hydrolyzing the fiber raw material by single-mode microwave radiation for 5 to 60 minutes at a temperature of between 20 and 50 DEG C and at the microwave radiation power of 10 to 100 watts, then adding distilled water into hydrolysis solution and diluting the hydrolysis solution to have 10 times of volume, and obtaining stable nano-rod cellulose suspension through post treatment processes such as centrifugal separation, dialysis, filter, ultrasonic dispersion and the like of the diluent, so as to obtain the nano-rod cellulose of which width is about 10 nanometers and length is about 200 to 300 nanometers.

The invention relates to a distributed energy management method and device. The distributed energy management device is composed of a ground layer, an intermediate layer and an energy management layer. The ground layer comprises a distributed power controller, an energy storage controller, a load controller, an invertor, a converter and a breaker. The intermediate layer comprises a data communication module, an operation control module, an energy storage management module and a load management module. The energy management layer comprises a data communication and monitoring module, an economic dispatch and optimal operation module, a load prediction module and a power generation prediction module. The ground layer and the intermediate layer coordinate and control short-term power in a local micro-grid system to be stable; the energy management layer coordinates and controls long-term power in the micro-grid system where the energy management layer belongs to be stable, and economization of micro-grid operation is achieved; meanwhile, the distributed energy management device is clear in structure, functions are specific, and system upgrade and function extension are facilitated.

The invention discloses a primary frequency modulation control method and system for a photovoltaic power station based on multi-master station coordination control. The method comprises the steps that the active power of the grid-connected point of the photovoltaic power station is collected in real time; since AGC load shedding control reserves power reserve capacity for the photovoltaic power station, the active power of the grid-connected point of the photovoltaic power station is active power Pref when the photovoltaic power station has the load shedding level described in the description; when the grid frequency exceeds the artificial dead zone DB disturbance of primary frequency modulation, a PFC control system calculates the active power variation delta P after frequency fluctuation, and the target value Pset=Pref+ delta P is given to the active power issued to an inverter group; and the active power of the photovoltaic power station is changed to achieve primary frequency modulation. The scheme simply needs to upgrade the algorithm of the control software of a conventional photovoltaic power station inverter, and adds a PFC master station coordination mechanism based on the existing AGC function of the power station, so as to realize multi-master station coordination control of AGC and PFC. Cost can be maximized. The primary frequency modulation function of the photovoltaic power station is used to speed up the frequency recovery of a grid.

A gas turbine control system is disclosed which operates to stabilize the system frequency in a case of transitional variations of the system frequency without making the strength of hot gas path parts of the gas turbine below a maximum stress value of the hot gas path parts. When a system frequency abnormality is detected, the output of the gas turbine is adjusted to recover the system frequency by making a gas turbine combustion gas temperature control inoperative. For this purpose, there are provided a logical circuit operative to make the gas turbine combustion gas temperature control disabled or inoperative in response to an abnormal system frequency detection signal, and a recovery circuit that operates to cancel the inoperative state of the gas turbine combustion gas temperature control. The detection of an abnormal system frequency may be carried out by an outside signal. An abnormality detection unit may be provided in a combined cycle plant.

The invention discloses a method and a device for stabilizing laser frequency and power. The method comprises the following steps of: obtaining primary diffracted light, and radiating the primary diffracted light into a photoelectric detector; detecting the intensity of the primary diffracted light; processing a detected signal; sending the processed signal to a driving source; and enabling an output signal of the driving source to act on an acoustic optical modulator. The device comprises a laser, the acoustic optical modulator, an electrooptical modulator, a polarization splitting prism, a quarter-wave plate and a Fabry-Perot interferometer. The method and the device have the advantages that reference precision and stability are greatly improved, better power stabilizing effect is realized, and frequency stabilizing effect is improved.

A switching power supply apparatus produces an output voltage by smoothing a pulsating voltage obtained by switching an input direct-current voltage with a switching device. The switching power supply apparatus has a current detection circuit that outputs a detection current that varies in proportion to the switch current flowing through the switching device, an overcurrent detection circuit that detects an overcurrent by comparing the detection current with a set current previously set so as to correspond to the overcurrent detection level and that, on detection of an overcurrent, feeds a reset signal to a flip-flop for controlling the switching of the switching device to turn the switching device off, and a second current compensation circuit that superimposes a compensation current on the detection current fed to the overcurrent detection circuit to produce a compensated current.

The invention discloses a single longitudinal-mode optical fiber laser with low noise, narrow linewidth and high power. Polarization maintaining optical fiber is rare-earth-doped phosphate single-mode glass optical fiber, the component of a fiber core is phosphate glass which consists of 70P2O5-8Al2O3-15BaO-4La2O3-3Nd2O3, the fiber core of the polarization maintaining optical fiber is doped with high-concentration luminous ions, the luminous ions are one or combination of more than one of lanthanide ions and transition metal ions, the doping density of the luminous ions is greater than 1*10<19>ions / cm<3> and the luminous ions are evenly doped in the fiber core. A polarization maintaining fiber Bragg grating with the narrow linewidth and a dichroscope form a front cavity mirror and a rear cavity mirror of the optical fiber laser, a centimeter-sized erbium-ytterbium co-doped phosphate glass polarization maintaining optical fiber is taken as a laser working substance, and polarization maintaining output laser generated by a single-mode semiconductor laser is taken as a pumping source, thus achieving the single longitudinal-mode laser output by designing and manufacturing the reflection spectrum width of the polarization maintaining fiber Bragg grating and controlling the cavity length of the whole laser cavity.

The present invention discloses an intelligent control method that a wind power plant participates in the primary frequency modulation and a control system thereof. The intelligent control method comprises the following steps of real-timely acquiring the power grid frequency of the high-voltage end of a wind power plant main transformer, determining whether the power grid frequency exceeds a set frequency dead zone, if the power grid frequency exceeds the set frequency dead zone, representing that the wind power plant needs to participate in the primary frequency modulation; calculating an active power superpose amount delta P needing to be adjusted; before the primary frequency modulation, calculating a draught fan target value Ptotal, and classifying the lists of the draught fans capableof participating in the modulation; according to the superpose amount delta P, making an adjusting cycle number needed by a frequency modulation task, then issuing the instructions of a first adjusting cycle to the wind turbine generator sets; monitoring the execution situations of the wind turbine generator sets, feeding back to an energy management platform, arranging a wind turbine generator optimal execution list to issue the instructions of a second adjusting cycle, and so on, finishing a primary frequency modulation task. According to the present invention, the instructions are issued in twice, the instructions at the first time are the tentative instructions, and by synthesizing the feedback information, the second time instructions are issued, so that the adjustment precision is higher.

An arrangement for power distribution on a vessel, having: a first DC bus operating at a first medium voltage; at least one second DC bus operating at a second medium voltage and having no direct connection with the first DC bus; a first AC bus operating at a low voltage; a first inverter coupled between the first DC bus and the first AC bus for allowing power flow from the first DC bus to the first AC bus in a first operation mode; a second AC bus operating at the low voltage; a second inverter coupled between the second DC bus and the second AC bus for allowing power flow from the second DC bus to the second AC bus in the first operation mode; a low voltage connection system for selectively connecting or disconnecting the first AC bus and the second AC bus.

Provided herein is a pulse laser generator including a modulator configured to receive a continuous wave laser, and to modulate an intensity and phase of the continuous wave laser to generate a first pulse laser; and a chirping unit configured to chirp the first pulse laser to generate a second pulse laser.

For the purpose of solving the above problems, the present invention includes: transmission / reception means provided in a flow path for performing transmission / reception using a state change of fluid; repetition means for repeating the transmission / reception; time measurement means for measuring a time of propagation repeated by the repetition means; flow rate detection means for detecting a flow rate based on a value of the time measurement means; and number-of-times change means for changing to a predetermined number of repetition times. With such a structure, an influence caused by a variation of a flow can be suppressed by changing the number of repetition times so as to be suitable for a variation. As a result, reliable flow rate measurement with a high accuracy can be achieved.

Method for stabilizing the frequency of a frequency synthesizer by means of a reference oscillator unit coupled to a voltage controlled oscillator (VCO) and a frequency synthesizer, wherein the synthesizer is provided with a phase locked loop (PLL) to stabilize the operation of the voltage controlled oscillator, wherein the reference oscillator unit is a MEMS (MicroElectromechanicalSystems) reference oscillator unit, the temperature of the MEMS reference oscillator unit is measured, and the output frequency is corrected according to the measured temperature by using a frequency / temperature function.