119results about How to "Solve Oscillation Problems" patented technology

The invention discloses a subsynchronous damping control system, and belongs to the power system stabilization and control technology field. The system includes a rotate speed testing and preposing processor, a combined mode filter, a combined proportion phase shifter, a mode control signal synthesizer and a nonlinear transformer. The system solves the problem of multimode subsynchronous resonance and oscillation of a power system, improves the subsynchronous stability of the power system, and reduces the shafting torsional oscillation fatigue loss of a large-size steam turbo generator.

The invention relates to a device structure with channel-oxide-nanotube super junction and a method for preparing the same and proposes a semiconductor power device precipitated on a first conductive type semiconductor substrate. The semiconductor substrate bears a second conductive type epitaxial layer, and the semiconductor power device is arranged on a super junction structure. The super junction structure comprises a plurality of grooves opened on the top face of the epitaxial layer, wherein the sidewalls of each of the grooves are covered with a first conductive type first epitaxial layer to neutralize the charge of the second conductive type epitaxial layer. The second conductive type epitaxial layer can be grown over the first epitaxial layer. Each of the groove is filled with a non-doped dielectric material in a remaining groove slot space. The sidewalls of each of the grooves have an angle of inclination to form a converged U-shaped groove.

The invention discloses a flameless combustion organizational structure used in a combustion chamber of a gas turbine. In the structure, a plurality of coaxial ejector nozzles are evenly arranged at one end of the cylinder-shaped combustion chamber in a ring shape; the center of the ejector nozzles evenly arranged in the ring shape is provided with a cylinder-shaped reflux structure; secondary air does not take part in combustion in the cylinder-shaped combustion chamber; the air taking part in the reaction enters from one end provided with the ejector nozzles arranged on the cylinder-shaped combustion chamber, and a large amount of reflux high-temperature fume is mixed with the fresh air according to the position relationship between the nozzle evenly arranged in the ring shape and the cylinder-shaped reflux structure arranged in the center of the nozzles, so that the air temperature is increased, and the air is diluted; and the diluted high-temperature air spontaneously combusts when exposed to the fuel to form a high-temperature dispersing reaction area, so that the flameless combustion is achieved in the combustion chamber of the gas turbine. The invention simultaneously discloses the flameless combustion chamber for realizing the flameless combustion organizational structure. The flameless combustion organizational structure and the flameless combustion chamber realize flameless combustion and achieve the aims of extremely low pollutant emission and stable combustion of the combustion chamber of the gas turbine.

The invention provides a flexible direct current additional subsynchronous oscillation control system for suppressing subsynchronous resonance and oscillation. The system comprises a feedback signal processor, a multi-mode band-pass filter, a multi-mode proportional phase shifter, a mode control signal synthesizer and an additional signal controller. A subsynchronous damping control strategy is added on a flexible direct current control system, a plurality of torsional vibration modes can be suppressed at the same time, functions are comprehensive, multi-mode subsynchronous resonance and oscillation of a power system can be achieved, subsynchronous stability of the system is improved, transmission capacity of a power grid is further improved, and safety of a generator is ensured.

The invention discloses a network deploying method, a network system and an IP node, which belong to the technical field of broadband internet, wherein the method comprises establishing a packet transmission layer with connection-oriented between an IP layer and an optical transport layer, and establishing a channel of the packet transmission layer with connection-oriented between any two IP nodes as a link between two IP nodes. The system comprises an IP layer and an optical transmission layer arranged on the lower layer of the IP layer, wherein a packet transmission layer with connection-oriented is further arranged between the IP layer and the optical transmission layer, and the IP layer comprises an IP node. The IP node comprises a connection establishing module. The network deployingmethod separates the IP layer from the optical transmission layer through establishing an MPLS-TE layer between the IP layer and the optical transmission layer and establishing LSP of the MPLS-TE between any two IP nodes as a link, and solves the oscillation of the IP layer.

The invention discloses a dead-beat prediction current control method for a permanent magnet synchronous motor. The method aims at overcoming the defects of: easily influencing the permanent magnet synchronous motor by digital system delay, inductance parameter mismatching and the like when dead-beat prediction current control is carried out, mainly observing load torque and obtaining a dynamic proportionality coefficient according to a preset dynamic proportionality coefficient expression; and combining the stator current sampling value of the current period, the stator current estimation value of the next period and the stator current instruction value through a dynamic proportionality coefficient, and performing dead-beat prediction current control by taking the combined value as feedback current in a prediction current controller, so that high-performance control on the permanent magnet synchronous motor is achieved. On the premise that the dynamic response speed of the control system is kept, the problem that the control system is influenced by digital system delay and inductance parameter disturbance is solved, the transient response performance of the system is enhanced, andthe robustness of the system is improved.

The invention discloses a tiny discharge gap bi-feedback adaptive analytic fuzzy servo control method, and belongs to the technical field of non-traditional micromachining. In the method, interpolar voltage or current signals which are fed back in real time are compared with a control target center so as to obtain signal errors and the change of the errors; a self regulating factor of an analytic fuzzy control rule in the whole field is dynamically adjusted, and the discharge gap servo control performance is improved; and then, in order to adapt to machining conditions and control errors introduced by process random change, a discharge statistics and parameter correction feedback channel is utilized to store and count an open circuit rate and a short circuit rate, and a fast convergence algorithm directly proportional to the open circuit rate and the short circuit rate is adopted, so that the control target center and an electrode advancing and retreating speed scale factor adaptively tend to be optimal simultaneously, and the open circuit rate tends to be equal to the short circuit rate and is the minimum, namely the discharge rate tends to be optimal. The method realizes the quickness, stability and accuracy of tiny discharge gap servo control and improves micro electrical discharge machining efficiency.

The invention discloses a maximum power tracker control method based on a generalized dynamic fuzzy neural network. The method is provided on the basis of the fuzzy neural network algorithm; the method includes adopting the fuzzy completeness based on elliptic basis function as an on-line distribution mechanism to avoid randomness of the initial selection; evaluating the importance of fuzzy rules, and responding to the importance of input variables; implementing on-line real-time adaptive adjustment of the width of the input variables of each rule according to the requirements of system performance. According to the method, the maximum power point can be found rapidly in 0.01 second by the aid of the generalized dynamic fuzzy neural network theory simulation results, the problem of oscillation of the maximum power point can be overcome effectively, and the robustness and fastness are high.

The invention belongs to the technical field of hydraulic adjustment and particularly relates to an automatic oil feeding type isomorphic double-cylinder leveling system. The system comprises a driving cylinder, a controller, a proportional solenoid valve, a driven cylinder and a redundancy inclined angle sensor, wherein rodless cavities of the driving cylinder and the driven cylinder are communicated and rod cavities of the driving cylinder and the driven cylinder are communicated; the controller is respectively and electrically connected with the redundancy inclined angle sensor and the proportional solenoid valve; the redundancy inclined angle sensor is used for feeding a detection result back to the controller; an output signal of the controller drives the opening and closing of the proportional solenoid valve; the proportional solenoid valve (3) can be used for carrying out oil supplementation on oil leaking cavities in the driving cylinder (1) and the driven cylinder (4). With the adoption of the system, the leveling process is safe and convenient and does not need to be subjected to artificially interfered; the problem that a working platform of an overhead working truck is inclined, caused by leaking of oil, is solved.

The invention belongs to the field of power systems, in particular relates to a method for distinguishing negative damping low frequency oscillation caused by a power generator excitation control system on the basis of moment decomposition integral algorithm. The method comprises the steps of: calculating a power generator transient state potential bias deltaE'q and determining a power generator speed bias delta omega, wherein the power generator speed bias delta omega is obtained through calculation according to a frequency of a potential EQ in a power generator, and whether damp provided by an excitation system of the unit is positive or negative relative to some oscillation mode in an Internet power grid is judged through calculating an integral value of the power generator transient state potential bias deltaE'q and the power generator speed bias delta omega. The method is convenient for measurement and is accurate, and can simply and clearly distinguish which oscillation mode of some power generator excitation control system provides a positive damp or negative damp so that measures are rapidly taken for inhibiting low frequency oscillation.

The invention discloses an improved rotational-inertia compensation method considering a communication time lag and an acceleration time lag.The problem that when a present wind turbine simulator simulates a large-rotational-inertia wind turbine, instability and vibration occur is solved.The compensation method includes the steps that a wind turbine simulator is tested to determine the rotational inertia of the wind turbine simulator; a wind turbine model simulated by the wind turbine simulator is determined, and the rotational inertia of the wind turbine model is determined; the wind turbine simulator is tested to determine the step length of the communication time lag; a filter is added into a dynamic-torque compensation branch circuit of the wind turbine simulator according to the situation; the parameters of the digital filter are adjusted, and the wind turbine simulator stably runs.By means of the compensation method, the instability problem, caused by the communication time lag and the acceleration time lag, of the WTS is solved, the WTS can stably simulate the large-rotational-inertia wind turbine in the mode that the influence of the time lag is eliminated, and a user is assisted in conducting a control experiment of the wind turbine in the laboratory environment.

The invention belongs to the filed of electric systems, in particular relating to a realizing method of identifying negative damping low-frequency oscillation which is caused by a generator excitation control system, based on a force moment decomposition method. The realizing method comprises the following steps of: calculating subtranient electric potential E'q of a generator and determining velocity deviation delta omega of the generator, wherein the velocity deviation delta omega of the generator is calculated according to frequency of inner electric potential EQ of the generator; and judging whether damping provided by the excitation system of a machine group for a certain oscillation mode in an interconnected power grid is positive or negative by comparing phase relation of the subtranient electric potential delta E'q of the generator and the velocity deviation delta omega of the generator. The realizing method disclosed by the invention is convenient to measure, is accurate, can simply and clearly identify the generator excitation control system which provides the negative damping for a certain negative damping oscillation mode so as to quickly inhibit low-frequency oscillation. The method is a pioneering at home.

The present invention provides a synchronous, continuous and adjustable power supply system. The synchronous, continuous and adjustable power supply system comprises a rectifying circuit, a PFC circuit, a disconnecting switch power supply, a low-noise adjustable power supply, a synchronizing pulse generator and a synchronizer trigger. The synchronous, continuous and adjustable power supply system enables the voltage outputted by the disconnecting switch power supply to be boosted and reduced via the low-noise adjustable power supply, so that the finally outputted voltage value is consistent with the voltage value set by a setter. A synchronous, continuous and adjustable power supply provided by the present invention, firstly possesses a low noise function and an efficient, continuous and stable adjustment function, and can solve the power supply oscillation problem in the 0V-90V continuous voltage adjustment and continuous current adjustment, secondly can realize a plurality of low-noise power supply systems and enables the PFC circuit and the disconnecting switch power supply to be controlled synchronously, and thirdly realizes the 100 Vac-240 Vac AC commercial power input and the 0 V-90 V continuous DC adjustable voltage output.

The invention discloses a voltage injection type SiC MOSFET active driving circuit. The voltage injection type SiC MOSFET active driving circuit includes a driving push-pull circuit, a driving resistor, a sampling circuit, a pulse generation circuit and a driving voltage compensation circuit, wherein the sampling circuit comprises a first resistor, a second resistor, a third resistor, a fourth resistor, a first capacitor and a second capacitor, the pulse generation circuit comprises a first comparator, a second comparator and a first logic AND gate, and the driving voltage compensation circuitcomprises a fifth resistor, a sixth resistor, a first switch tube, a second switch tube and a first diode. According to the active driving circuit provided by the embodiment of the invention, the sampling circuit detects the driving pulse, so that the pulse generation circuit generates a compensation signal in the drain current drop stage in the SiC MOSFET turn-off process; Through the driving voltage compensation circuit, the gate voltage is compensated to raise the gate voltage and inhibit the change rate of the current so as to inhibit the voltage peak and oscillation at the two ends of the SiC MOSFET.

The disclosure provides a frequency conversion control device and control method for a heat pump. The frequency conversion control device comprises a loop formed by an evaporator, a compressor, a condenser and an electronic expansion valve, wherein the electronic expansion valve is driven by a controller through a driver; the compressor is controlled by the controller to realize frequency conversion control through a frequency converter; the controller receives acquired temperature and pressure of a refrigerant at an evaporator outlet and indoor temperature; the controller realizes respective control of the frequency of a compressor frequency converter and the opening degree of the electronic expansion valve to the indoor temperature and the superheat degree of the refrigerant at the evaporator outlet based on data acquired in real time by adopting a bivariate adaptive fuzzy control strategy. According to the control device, the superheat degree of the refrigerant at the evaporator outlet is controlled by using the electronic expansion valve; and the indoor temperature is controlled by adjusting the operation frequency of the compressor.

The invention discloses an electromagnetic transient numerical computation method based on a 3-step 4-order implicit Taylor series method. The method comprises the following steps: establishing a timedomain differential equation for electromagnetic transient numerical computation of a power system, performing time domain numerical integral computation by adopting an A-stable and infinitely stable3-step 4-order implicit Taylor series method, and gradually solving a change curve of each state variable with time. The 3-step 4-order implicit Taylor series method adopted by the invention is an A-stable and infinitely stable numerical method, has a faster attenuation rate for truncation errors, can effectively inhibit numerical oscillation, and can thoroughly avoid the problem of numerical oscillation compared with an implicit trapezoidal integral method. In addition, according to the 3-step 4-order implicit Taylor series method adopted by the invention, the computation accuracy is 6-order, the local truncation error is 0(h8), and the computation efficiency can be improved by adopting a larger integral step size. Compared with a CDA method, the electromagnetic transient numerical computation method based on the 3-step 4-order implicit Taylor series method can completely avoid the problem of numerical oscillation, and is also higher in computation accuracy and efficiency and stronger in numerical stability.

The invention provides a virtual guide ship automatic berthing control method based on a self-adaptive dynamic programming algorithm. The method comprises the steps: establishing a ship berthing nonlinear control system mathematical model; introducing a virtual guidance system based on the established ship berthing nonlinear control system mathematical model to obtain an optimal controller, and converting a berthing control problem into a tracking control problem; based on the optimal controller, establishing an optimal berthing evaluation index; converting a tracking control problem into an optimal adjustment problem; designing optimal berthing control of the ship based on an adaptive dynamic planning method, and approaching an optimal berthing evaluation index; and executing optimal berthing control of the ship through the neural network to obtain an optimal berthing control law. According to the technical scheme, the problem of automatic berthing of the ship with an unknown model dynamic state is solved, the energy consumption of the controller is effectively reduced, and the ship tracking precision is improved, so that the optimal berthing path is obtained.

The invention discloses an electromagnetic transient numerical analysis method based on a two-stage three-order single diagonally implicit Runge-Kutta method. The electromagnetic transient numerical analysis method is characterized by comprising: establishing a time-domain differential equation for electromagnetic transient numerical calculation of a power system; performing time-domain numerical integration calculation with the B-stability two-stage three-order single diagonally implicit Runge-Kutta method; and stepwise solving a curve of change of each physical variable along with time. Compared with a classical electromagnetic transient numerical calculation method based on an implicit trapezoidal integration method, the electromagnetic transient numerical calculation method based on the two-stage three-order single diagonally implicit Runge-Kutta method can avoid the numerical oscillation problem; compared with a CDA method, the electromagnetic transient numerical calculation method based on the two-stage three-order single diagonally implicit Runge-Kutta method not only can completely avoid the numerical oscillation problem but also is higher in calculation efficiency; and compared with a numerical method (1), the electromagnetic transient numerical calculation method based on the two-stage three-order single diagonally implicit Runge-Kutta method is remarkably improved in calculation efficiency.

The invention discloses an adaptive incremental conductance MPPT algorithm which is based on the incremental conductance algorithm and uses multiple step models combined with allowable errors to accurately control the converting circuit duty ratio D and to increase tracking efficiency and accurately respond to rapidly changing lighting conditions. The adaptive incremental conductance MPPT of the invention is characterized by quick tracking and accurate response under sudden changes in illumination with little fluctuation and without stable oscillation. Compared with the existing MPPT, the invention has better tracking performance, accurate response, no oscillation, high tracking efficiency, easy implementation, and reduced energy loss. The invention solves the problems that the existing algorithms often have oscillation, inaccurate response, low tracking efficiency and high difficulty in implementation. The improved step size model and precise directional control in the algorithm of the present invention are effective.