231results about How to "Suppresses voltage fluctuations" patented technology

An interface device transmits a reactive power command depending on a power system from a voltage regulation device of the power system to a wind power generation apparatus electrically connected to the power system, and the wind power generation apparatus receives the reactive power command. Then, the wind power generation apparatus outputs reactive power according to a value obtained by adding, to a reactive power command, another reactive power command for suppression of voltage fluctuation caused by output power of the wind power generation apparatus.

The invention discloses a wind power station reactive power control method and a system. The wind power station high voltage side bus voltage is used as a control target, the reactive power is used as the regulating quantity, the wind power station voltage control strategy and the power factor control strategy are selected or the system reactive power output is forcibly controlled to be a constant value according to the wind power station voltage fluctuation range and the power factors, and in addition, the reactive power output values of each fan and integrated reactive compensation equipment in the wind power station are determined according to the reactive power reference values required to be output by the wind power station. When the technology of the invention is adopted, the reactive power output of the wind power station networking points meets the system requirements for inhibiting the bus voltage fluctuation and regulating the wind power station power factor, and in addition, the reactive power output of each wind power generator set and integrated reactive compensation equipment in the wind power station can be controlled in a harmonious way.

A desired value of reactive power flow between a to-be-controlled power system and an adjoining power system is determined according to measured values of the reactive power flow and an effective power flow and desired voltage values of the to-be-controlled power system and of the adjoining power system. Thereafter, a required value of a reactive power of the to-be-controlled power system is calculated according to the desired value of the reactive power flow, the measured values of the reactive power flow and the effective power flow, and the desired voltage value and a measured voltage value in the to-be-controlled power system. Thereafter, a control apparatus having an electric capacity near to the required value of the reactive power is selected from control apparatus arranged in the to-be-controlled power system to make the selected control apparatus adjust a voltage of the to-be-controlled power system. Therefore, cooperation of the to-be-controlled power system with the adjoining power system can be performed by collecting locally-existing-information, and a voltage fluctuation and / or a reactive power fluctuation in the to-be-controlled power system can be immediately suppressed.

A distributed generation system that can suppress a voltage fluctuation caused by a distributed generation by an apparatus of a small power capacity in the distributed generation itself and stabilize the power system voltage without inserting interharmonic voltage or current into the power system and without interference among a plurality of distributed generations. Parameter α(t) varying with time is estimated based on fluctuating component ΔP of the active power P generated by the distributed generation and the voltage fluctuating component ΔV attributable to the distributed generation developed at the point of connection between the distributed generation and power system. The distributed generation produces reactive power Q=−αP or Q=−αΔP, to thereby suppresses only the voltage fluctuation of the power system attributable to the distributed generation.

A battery-state monitoring system for precisely and efficiently estimating the state and service life of each of a plurality of storage batteries while suppressing variations in voltage between the batteries in a large-scale power-supply system that is provided with the storage batteries charged with power generated by utilizing natural energy is provided. The system includes a power supply control device that detects a current in each storage battery, an end device that measures temperature, voltage, and internal resistance of each battery, the internal resistance being measured by using at least two or more kinds of frequencies, and a prime monitoring device that acquires measurement data from the end device corresponding to each battery and issues an instruction related to an operation to the power supply control device and the end device. The prime monitoring device estimates degradation of each battery based on one or more of temperature, voltage, internal resistance.

The invention relates to a robust autonomous control method for the bus voltage of the DC micro grid. A nonlinear interference observer, DC bus voltage sagging control and voltage / current double-loop control are combined in the method. The method comprises that a DC-DC current transformer model is established; the nonlinear interference observer is used to track output current of the DC-DC current transformer model, and a band pass filtering link based on a second-order general integration link is used to filter output results of the observer; in DC bus voltage sagging control, the output results of the nonlinear interference observer serve as the output current; and in voltage / current double-loop control, perturbation current of the output results of the nonlinear interference observer is used for feedforward control. The method can be used to realize peer-to-peer control and autonomous operation of the DC micro grid, effectively improves dynamic response of the control system, inhibits fluctuation and impact of transient DC bus voltage, and is conducive to expansion and plug-and-play of distributed power supplies and loads in the DC micro grid.

The invention belongs to the field of power systems, in particular to a reactive-load compensation equipment application scheme for large-scale wind power delivery system. As for the large-scale wind power delivery system, the invention, aiming to meet the needs of power delivery and wind power access, through reactive power balance analysis in different level years and under different operation modes, provides the capacitive and inductive reactive power demands of each substation in the system, and provides a configuration scheme for low pressure side fixed switching reactive compensation equipment such as capacitors, reactors and the like and dynamic reactive-load compensation equipment such as controllable reactors, static var compensators and the like. The provided configuration scheme can ensure voltage at each point in the system is controlled within a reasonable range under different operation modes, and meanwhile the dynamic reactive-load compensation equipment can meet the requirements of reactive power control of the grid and the voltage under wind power fluctuations with a strong engineering adaptability.

The invention discloses a voltage and power regulator based on the composite energy storage of a storage battery and a super capacitor. The regulator comprises an energy storage module, an electricity-electron transformation module and a transformer; the energy storage module comprises a plurality of composite energy storage units and the electricity-electron transformation module comprises a plurality of electricity-electron transformers; all the composite energy storage units are connected at the direct current bus side of the electricity-electron transformers in parallel and the alternating current side of each electricity-electron transformer is connected with the auxiliary-side winding of a voltage transformer correspondingly while the original-side winding thereof is connected into a power network. When in normal operation, the regulator can provide reactive power compensation for the power network to effectively stabilize the active power fluctuation; when failure or switching load transmission operation occurs in the power supply line, the regulator provides short-time power supply for load so as to avoid load power supply interruption and further rapidly traces the voltage magnitude and phase of spare lines, thereby realizing that no impact is made in a spare power circuit.

A system-on-a-chip and a power gating circuit thereof are provided. The power gating circuit includes a first transistor, a charge pump circuit, and a hold circuit. A gate terminal of the first transistor is controlled by a first input signal. A first source / drain terminal of the first transistor is coupled to a first voltage. A second source / drain terminal of the first transistor outputs an output voltage. The charge pump circuit is coupled to a bulk terminal of the first transistor for changing a bulk voltage of the first transistor according to a second input signal. The hold circuit is coupled to the bulk terminal of the first transistor for holding the bulk voltage of the first transistor.

The invention discloses a tidal current control device for a V / v traction substation of an electrified railway. The device consists of a static power adjuster, a TCR filter and an LC filter (FC), wherein the static power adjuster is mounted on the secondary side of the V / v traction substation, and a back-to-back structure is formed by the static power adjuster and a capacity on the public direct current side; the alternating current side of a current converter is connected to power supply arms on the secondary side of the traction substation respectively through a voltage drop transformer; an FC filter is connected to a phase a of the secondary side of the V / v traction substation, and the TCR filter is connected to a phase b of the secondary side of the V / v traction substation. All parameters are calculated by capacity optimization, so that the cost and the system harmonic absorption content can be reduced. A double-closed-loop controller is used for controlling the tidal current distribution of the two power supply arms, so that multi-mode tidal current control is realized; by matching of the V / v traction substation, the TCR filter, the FC filter and the static power adjuster, multi-mode tidal current double-closed-loop control on the traction substation of the electrified railway is realized; voltage fluctuation is suppressed, main harmonics are effectively shielded, and comprehensive negative sequence and reactive treatment is realized.

A method for manufacturing a semiconductor device according to the present invention has a step of forming a plurality of MOSFETs each having a channel of a first conductivity type in a stripe on the first major surface of a wafer; a step of implanting an impurity of a first conductivity type into the second major surface of the wafer, and performing a laser annealing treatment in a stripe leaving equidistant gaps, to form a buffer layer that has been activated in a stripe; a step of implanting an impurity of a second conductivity type into the second major surface of the substrate after forming the buffer layer, and performing a laser annealing treatment on the entire surface of the second major surface, to form a collector layer, and to activate the buffer layer; and a step of forming an emitter electrode on the first major surface, and forming a collector electrode on the second major surface.

The invention discloses a positive and negative sequence double-ring superposition control method of distribution static synchronous compensator based on instantaneous power balance, which consists of a positive sequence control ring and a negative sequence control ring. The method comprises following steps: deducing a current-voltage conversion formula in a d-q positive-sequence and negative-sequence coordinate system according to an instantaneous power balance formula to obtain a positive-sequence voltage modulation signal and a negative-sequence voltage modulation signal; superposing the positive-sequence voltage modulation signal and the negative-sequence voltage modulation signal to obtain a DSTATCOM output voltage modulation signal; and modulating by a triangular carrier wave to produce a PWM drive signal to control the action of an intelligent power module IPM to generate a required compensation voltage. The control method can achieve unbalanced three-phase voltage control of a common connection point, and the current-voltage conversion formula in the d-q positive-sequence and negative-sequence coordinate system is deduced by the instantaneous power balance formula, thus obviating complex mathematic operation in conventional current control method and further lowering the cost.

In a substrate for a stacking-type semiconductor device including a connection terminal provided for a connection with a semiconductor chip to be stacked and an external terminal connected to the connection terminal through a conductor provided in a substrate, connection terminals of a power supply, a ground and the like, which terminals have an identical node, are electrically continuous with each other. Thus, it is possible to facilitate an inspection of electrical continuity between each connection terminal and an external terminal corresponding to each connection terminal by minimum addition of inspecting terminals. Further, it is possible to improve reliability of a stacking-type semiconductor module.

This invention provides a small package board integrated with power supply capable of supplying a low level of voltage and high level of current to an IC while achieving a low height of its power supply. It becomes hard to saturate an inductor magnetically when the surface of a copper wire is coated with a magnetic layer, and the inductor can accordingly be provided with a sufficient degree of inductance. A multiplicity of inductors can be provided within a confined space by arranging a multiplicity of inductors in parallel, and by fixing them with resin so as to form an inductor array, thereby making it possible to divide a power supply. The number of power supply lines is increased by dividing the power supply so as to reduce the level of current in an individual power supply line, so that a high level of current can be supplied to an IC chip. Further, a distance between a power supply and the IC chip can be decreased by incorporating a power supply module into the package board so as to reduce generation of heat and curb a drop in voltage in the power supply line, thereby making it possible to supply a high level of current to the IC chip.

A surge voltage target setting unit (103) acquires a main circuit power source voltage (VH) of a semiconductor power conversion device, on the basis of the inter-terminal voltage (Vce) of a semiconductor switching element (100) detected by a voltage detecting unit (102), and sets the control target (Vm) of a surge voltage in accordance with the main circuit power source voltage acquired. When the inter-terminal voltage (Vce) exceeds the control target (Vm) at the turn-off time of the semiconductor switching element (100), an active gate control unit (71) sets a voltage correction quantity (V1), on the basis of the feedback of the inter-terminal voltage (Vce), so that the gate voltage (Vg) is corrected in a direction to raise a gate voltage (Vg), i.e., in a direction to reduce a turn-off rate.

The invention discloses a DC micro grid bus voltage control strategy based on hybrid energy storage. By use of high power density of a super capacitor and a high-energy-density feature of a storage battery, according to a voltage change rate of DC bus voltages, the bus voltages are processed segment by segment under different voltage conditions, the DC bus voltage stability is improved through two different energy storage control strategies, variation of the DC bus voltages can be inhibited, the satiability of the DC micro grid bus voltages is ensured, and the application prospect is good.

The invention discloses a power grid voltage regulation method of an angle form cascade synchronous compensator. Unbalanced three-phase power grid voltage is independently subjected to positive and negative sequence voltage detection to obtain positive sequence voltage dq shaft components Vd[P] and Vq[P] and negative sequence voltage dq shaft components Vd[N] and Vq[N]; a difference value between the positive sequence voltage dq shaft components and a voltage control instruction as well as a difference between the negative sequence voltage dq shaft components and the voltage control instruction can be independently obtained, and a deviation is subjected to slip form PI control to obtain a STATCOM (Satellite Communications) line current positive and negative sequence dq shaft control instruction; after the STATCOM line current positive and negative sequence dq shaft control instruction is subjected to synchronous frame transform, zero sequence circulating current is combined to obtain a STATCOM phase current instruction; the STATCOM phase current instruction is subjected to current dead-beat control to obtain each-phase chain link modulating wave signal; carrier phase-shifting modulation is used for controlling each module switch to act, finally, positive sequence reactive current and negative sequence current are injected into a power grid, the positive sequence voltage of the power grid is supported, and the voltage fluctuation of a point of common coupling is reduced; and the negative sequence voltage of the point of common coupling is inhibited, and the unbalance of power grid voltage is improved. A slip form PI control method adopted by the invention can quickly support the positive sequence voltage of the power grid, control the positive sequence voltage of the power grid, inhibit short-time voltage leap and maintain the stability of the power grid voltage.

The invention provides a voltage fluctuation restraining method for a high-frequency zero-sequence voltage injection cascaded static synchronous compensator (STACOM) and belongs to reactive compensation device control methods of power electronics. The method comprises the five steps that firstly, a power grid voltage vector angle is obtained, and synchronous rotation transformation among three kinds of signals such as power grid voltage, compensating currents and a modulating signal obtained according to a master control algorithm is achieved; secondly, compensating current detection and coordinate transformation are carried out, and a triple frequency zero-sequence voltage phase angle is obtained through calculation; thirdly, a triple frequency zero-sequence voltage amplitude is obtained through calculation; fourthly, the triple frequency zero-sequence voltage phase angle is obtained, and a final modulating signal is obtained by adding an instantaneous value to the modulating signal obtained according to the master control algorithm; fifthly, triple frequency zero-sequence voltage injection and PWM signal generation are carried out, three-phase PWM signals are generated, and STACOM capacitor voltage fluctuation restraining is completed. The capacitor voltage fluctuation frequency on the direct current side of the STACOM is converted into quadruplicated frequency from double frequency, the fluctuation amplitude is reduced by half, direct current voltage is stabilized, and the service life of a capacitor is prolonged.

In this method, the space voltage vector of the alternate current output voltage of the inverter, according to its valve in the Alpha, Beta coordinate system, is arranged into the vector distribution map of a hexagon, which is combined by 24 equilateral triangle and the corresponding status of the switch, the optimization modulation is processed. The optimization allows only one switch change status when the adjacent switches switch over.

A phase interpolator includes a first to a fourth differential pair. Each of the differential pairs includes a first and a second transistor and a stabilizing capacitor connected between a source coupled node and a reference voltage. The phase interpolator also includes a plurality of current sources and a group of switches to switch connections between the source coupled nodes of the differential pairs and the current sources so that (i) a first operating current is supplied to a first selected one of the first and second differential pairs and (ii) a second operating current is supplied to a second selected one of the third and fourth differential pairs. Drains of the first transistors in the differential pairs are commonly connected and drains of the second transistors in the differential pairs are commonly connected to form a first and a second output node so that a differential output signal is output.

The invention discloses a micro-grid system monitoring method having a reactive automatic compensation function. The method includes steps of S1, obtaining a wind power unit operation data in real time and storing data by a wind power unit monitoring unit, obtaining micro-grid inner load power demand condition in real time, and performing prediction on output active power and reactive power of a wind power unit in a future predetermined moment according to the operation data of the wind power unit; S2, collecting grid connecting point voltage information and determining micro-grid active and reactive output demand according to large-grid scheduling commands at the same time; S3, realizing reactive optimization operation of the micro-grid by taking the micro-grid active and reactive output demand, current micro-grid inner load power demand, wind power unit output active and reactive power, SVG device output reactive power as constraint conditions and inhibiting voltage fluctuation. The method can predicate power generation power of the wind power unit in the micro-grid and load change of the micro-grid. By the combination with a multi-target optimization reactive power distribution method having active loss influence in the micro-grid under a wind power unit constant active power control mode, economical operation of the micro-grid is improved, participation of bulk power grid voltage adjustment of the micro-grid according to requirements of a bulk power grid during grid connection is ensured and voltage stability during grid-connected operation is guaranteed.

A multilayer capacitor configured of internal electrodes, each of which has a similar shape that is continuous and has a pair of parallel parts extending parallel to one another. First and second ends of each internal electrode are formed at different positions from those of the other internal electrodes in the stacking direction of the dielectric layers. Each of the internal electrodes has a width W1 that is substantially uniform from the first end to the second end and a length L of a path running through the center of the width W1 from the first to the second end, such that the length L and the width W1 satisfy the expression 8≦L / W1≦33. With this construction, the equivalent series resistance (ESR) of the multilayer capacitor can be maintained within a suitable range, making it possible to obtain a desired value of ESR.

The invention discloses a method for stabilizing voltage fluctuation of a wind power micro-grid employing super capacitors, and relates to the technical fields of micro-grids and wind power generation, in particular to wind power stabilization employing the super capacitors in the wind power micro-grid. The method is mainly applied to stabilization of the voltage fluctuation in the micro-grid which is composed of a wind power system. The invention provides a detailed principle and a system structure diagram for stabilizing the voltage fluctuation of the wind power micro-grid employing the super capacitors. The system comprises a wind power generation unit, a capacitance compensation device, a super capacitor bank, a two-way direct-current / direct-current (DC / DC) converter, a voltage source inverter and a filter circuit. As a super capacitor energy storage unit and a direct-current bus interface, the structure of the boost-buck two-way DC / DC converter is analyzed; and through pulse-width modulation (PWM) control, the duty ratios of switch tubes T1 and T2 are changed, so that charge and discharge control by the super capacitors is realized; the DC / DC converter is controlled by an outer voltage loop and inner current loop double-closed loop control strategy; and meanwhile, the specific control mode of power exchange by the super capacitors is provided.

Disclosed in the invention is an integrated optimization system of an electric energy quality of a power distribution network. The system is composed of a monitoring server, optimizing devices, and wireless data transmission modules. The optimizing devices consist of three-phase detection modules, reactive power detection modules, harmonic detection modules, and voltage detection modules. The monitoring server includes a three-phase adjustment module, a reactive power compensation module, a harmonic filtering module, and a voltage regulation module. With the system, defects of compensation of the traditional capacitor can be overcome; the electric energy quality and energy conversion application requirements of the power distribution network can be met; and the electric energy quality can be improved substantially. On the basis of the modular design, reactive compensation, harmonic wave filtering, and three-phase unbalance inhibition of all modules can be realized independently or simultaneously; and non-capacity attenuation is realized and the service life is long.

The invention discloses a method and system for allocation of the reactive compensation capacity of a microgrid. According to the method and system for allocation of the reactive compensation capacity of the microgrid, system data of the microgrid are obtained by an acquisition module, a reactive power optimization model is established by a processing module according to the system data and preset constraint conditions, an optimization result is output by an optimization module according to the reactive power optimization model, and then reactive power optimization is carried out on the microgrid. According to the method and system for allocation of the reactive compensation capacity of the microgrid, reactive power optimization is carried out on the microgrid to achieve the purposes of the minimum active power loss of the microgrid and the minimum average voltage deviation of the microgrid through the reactive power optimization model, the reactive compensation capacity of a reactive compensation device when the reactive power optimization value is smallest serves as an optimization result, voltage fluctuation, caused by output fluctuation of a micro source, of the microgrid can be effectively restrained, stability of the microgrid is improved, power quality of a power supply is improved, loss of the microgrid is reduced, and the overall utilization rate of electric energy is improved.

The invention discloses a method for carrying out intelligent control on the dynamic reactive power compensation of a SVG (TSC) (static var generator (thyristor switched capacitor)), which comprises the following steps of: controlling the SVG and the TSC by using a master control unit; carrying out centralized sampling, calculation and control by using the master control unit, and automatically adjusting to adopt a reactive power compensation mode of the SVG and adopt a reactive power compensation mode of the TSC; and preferably starting the reactive power compensation mode of the SVG, and when the SVG has a fault, adopting the reactive power compensation mode of the TSC. When the reactive power demand of a system is instantly changed dynamically, the SVG starts a PWM (pulse-width modulation) control program at a predetermined response speed firstly, and then outputs compensation currents so as to rapidly and dynamically adjust the variable quantity of reactive power; and when the load of the electric power system is changed within a large range and exceeds the capacity of the SVG, a grouping switch function of the TSC is started so as to compensate the reactive power demand of the system. The method for carrying out intelligent control on the dynamic reactive power compensation of the SVG (TSC), disclosed by the invention, has the advantages that: the response speed of reactive power compensation can be improved, an effect of carrying out dynamic and continuous adjustment on reactive power can be achieved, and the like.

The embodiment of the invention discloses a method and system for inhibiting voltage fluctuation of a photovoltaic power station. The method includes the steps that a first voltage Vp1 and a first current Ip1 of a public coupling point are detected at a first moment, and active power P1 of the public coupling point at the first moment is obtained through the Vp1 and the Ip1; a second voltage Vp2 and a second current Ip2 of the public coupling point are detected at a second moment, active power P2 of the public coupling point at the second moment is obtained through the Vp2 and the Ip2, and the absolute value of the difference of the P1 and the P2 is larger than the first preset value; the grid impedance ratio is obtained through the Vp1, the Ip1, the Vp2 and the Ip2; a first inverter is controlled to output first reactive power Q1, and Q1=K*P11; the P11 is active power currently output by the first inverter; a second inverter is controlled to output second reactive power Q2, and Q2=K*P12; the P12 is active power currently output by the second inverter. The method is simple, the real-time request of communication is not high, and the inverters do not need to be controlled in real time to conduct reactive power adjustment; the reactive power output by the inverters needs to be adjusted only when the grid impedance ratio changes.