164 results about "Power system stabiliser" patented technology

The invention provides a method for implementing a parallel power system stabilizer (PSS). The parallel PSS of the invention divides compensation frequency domain of the existing PSS into two sections and compensates the compensation frequency domain by two compensation branches respectively, wherein, in one compensation branch, a gain regulating link is used for improving the amplitude of a high-frequency section, while in the other compensation branch, a lag compensation parameter is used for solving the shortage of compensation in a low-frequency section. As the same as the existing PSS, the parallel PSS of the invention can improve the stability of the small perturbation of the system and inhibit the low-frequency oscillation in an interconnected system. Compared with the existing PSS, the parallel PSS of the invention improves the phase-frequency characteristic of the low-frequency section and the amplitude-frequency characteristic of the high-frequency section, thereby widening the working frequency domain of the parallel PSS of the invention, and inhibiting the reactive power fluctuation while the system is in normal operation.

A power system stabilizer includes: a sensor configured for sensing a signal representative of electromechanical oscillations of the power system; a controller configured for using the sensed signal for generating control signals for damping the electromechanical oscillations; and a damper including a damping converter and a resistor coupled to the damping converter, the damping converter being coupled to the power system through a power bus, the damping converter configured for using the control signals for damping the electromechanical oscillations.

A system and method for monitoring the power damping compliance of a power generation unit comprises a measurement unit that is configured to be coupled to a power generation unit to identify the voltage, current, and frequency values associated with power output therefrom. A processing system maintaining a model-based filter processes the voltage, current, and, frequency values to estimate the total amount of damping provided by the power generation unit. The estimated total damping is compared to prior historical values maintained in a database using various statistical techniques to determine if a power system stabilizer (PSS) provided by the power generation unit is being operated in a manner complying with predetermined guidelines.

The invention discloses a design method of a stabilizer of a power system in the technical field of stable control of the power system. The method comprises the following steps: selecting a variable corresponding to maximum feedback gain from a full-state feedback gain matrix of the system as a primary variable; and adjusting the feedback gain of the primary variable for realizing the control of damping of the system, and setting a zero point of the system in a matching way for adjusting oscillation mode. By adopting the method, low-frequency oscillation of the system is effectively inhibited, the problem that the overall control effect of the stabilizer is affected due to unreasonable pole configuration of a state variable observer when adopting the full-state feedback control is simultaneously avoided, and the good control effect is realized.

The invention discloses a method for implementing a power system stabilizer. The method includes steps of acquiring a rotation speed variable quantity via a blocking filter link according to the rotation speed and active power of a rotor of a power generator, and respectively acquiring low-band differential signals, medium-band differential signals and high-band differential signals via a differential filter; parallelly adding the low-band differential signals, the medium-band differential signals and the high-band differential signals together to acquire rotation speed variation comprehensive signals of the power generator; measuring phase-shift characteristics of the rotation speed variation comprehensive signals and the rotation speed and uncompensated phase-shift characteristics of an excitation control system of the power generator by a forced oscillation process, computing required phase-shift characteristics among the rotation speed variation comprehensive signals and the power system stabilizer, designing multi-order lead-lag link phase-shift parameters which are serially multiplied by one another, performing phase compensation to meet the required phase-shift characteristics; finally outputting signals of the power system stabilizer and superposing the signals of the power system stabilizer on a reference voltage of an excitation regulator of the power generator. The method has the advantage that active power low-frequency oscillation of the synchronous generator can be effectively suppressed.

The invention discloses a fault protection and ride-through control system and method for a virtual synchronous machine. The fault protection and ride-through control method for the virtual synchronous machine comprises the following steps of measuring the three-phase voltage and current on the inverter output side, and calculating the active power according to an instantaneous power theory; if an asymmetric voltage drop fault occurs, extracting the voltage positive sequence component of the power grid to obtain a switching signal, and calculating the correction amount when the active power and the reactive power need to be output; if the voltage drop depth of the power grid exceeds a preset value, obtaining a supporting voltage through a power system stabilizer; and performing calculation and regulation through an active equation, a reactive equation, a torque inertia equation, and an electromagnetic torque equation to obtain the amplitude value and the phase angle setting value of the output voltage, and performing PWM modulation. According to the fault protection and ride-through control system and method, an energy storage unit is adopted for performing voltage-stabilizing control; and the direct bus voltage is stabilized while it is ensured that overcurrent does not occur, so that huge voltage fluctuation is avoided, and the performance degradation of the system is prevented.

The invention discloses a setting algorithm of parameters of a power system stabilizer. In the algorithm, an all-frequency band optimization algorithm and a specific frequency band optimization algorithm are adopted, and setting of the common parameters of the power system stabilizer including PSS1A, PSS2A, PSS2B and H infinity types can be performed. The method can be adapted to change of a power grid operation mode, and can have a good suppression action on both wider frequency oscillation and specific frequency oscillation. The method is applied to setting the parameters of the power system stabilizer, thus the power system stabilizer can give full play to improving dynamic stability of the power grid and preventing low-frequency oscillation.

An intelligent optimizing method of power system stabilizer parameter in the field of power system stability control technology is provided, comprising: step one, encoding each parameter by using quantum bit angle limited in the first quadrant, forming the first group, and confirming the maximum iterative times; step two, generating random numbers between [0 to 90 degrees] aiming at each quantum bit angle in chromosome of the present group; processing collapsing operation to form binary serial according to the size relation of the random number identical quantum bit angle, converting the binary serial to the decimal power system stabilizer parameter; step three, calculating the adaptation value of the chromosome and recording the historical optimal binary solution and overall optimal binary solution of the chromosome; step four, using the particle-like group optimizing method to update the quantum gate; step five, if convergent or reaching the maximum iterative times, the calculation stops and the parameter is outputted; otherwise, returning to step two. This invention has faster convergent speed and greater optimizing result.

A technique with which a change in power frequency can be suppressed. A power system stabilizer issues a control command to a first storage battery among a plurality of first power generators and the first storage battery that are connected to an isolated island system via a first tie-line. The power system stabilizer includes a parameter determination unit and a control block unit. The parameter determination unit obtains, on the basis of operation information, a rate-of-change limit value that indicates a limit to be imposed on a total value of changes in the overall output of first power generators in operation. The control block unit generates a command value to be given to the first storage battery on the basis of an interconnection point power flow value measured on the first tie-line and the rate-of-change limit value obtained by the parameter determination unit.

A low-frequency band suppression enhanced anti-reversal power system stabilizer is presented by the invention. Currently the widely used PSS2B power system stabilizer needs lead elements above Order 2 to meet the phase compensation requirement of DC blocking signal of active power, thus quickly increasing high-frequency band gain, restricting allowable total setting gain of PSS, limiting low-band gain and reducing low-frequency band suppression ability of power system stabilizer. The invention will add generator speed signal ω (which is treated by DC blocking element and corrected by parallel proportional differential PD) and active power signal P_e (which is treated by DC blocking element and gained by gain factor K_s3) to get equivalent synthetic mechanical power of power system stabilizer. The actual active power signal gained by gain factor K_S1 can meet the requirement of phase compensation through Order 1 lead and lag elements, thus increasing allowable total setting gain of PSS and improving the ability of low-frequency band oscillation suppression.

The invention discloses a double-fed wind power generation system based on a vector power system stabilizer. The double-fed wind power generation system comprises a wind turbine, a gear case, a power generator, a rotor-side converter, a grid-side converter, a direct current capacitor, a filter, a rotor-side controller, a vector signal collecting device and the vector power system stabilizer. The input end of the vector signal collecting device is connected with a power grid; the input end of the vector power system stabilizer is connected with the output end of the vector signal collecting device; the first input end of the rotor-side controller is connected to the input end of the power generator, the second input end of the rotor-side controller is connected to the power grid, the third input end of the rotor-side controller is connected to the output end of the vector power system stabilizer, and the output end of the rotor-side controller is connected to the control end of the rotor-side converter. According to the double-fed wind power generation system, wind turbine terminal voltage vector signals are introduced to serve as input signals for obtaining electromagnetic torque control compensation signals and terminal voltage control compensation signals, the terminal voltage amplitude and the terminal voltage phase angle are completely considered, terminal voltage vectors serve as input signals of the vector power system stabilizer, and disturbance of the electromechanical time scale of the power grid is comprehensively reflected.

The invention provides a method and system for setting parameters of a power system stabilizer of a speed regulation system. The whole computational process is easy and convenient, complex computation is not required, and obtaining and computation of data are computed and processed according to the requirements of the current environment, so that the method and system are suitable for various different situations, the practicability is high, and the computation is precise. In addition, the GPSS restraining low-frequency oscillation method is adopted, due to the fact that GPSSs of other generator sets and power grid models are not depended on, the decoupling analysis of multiple machines is achieved, and the efficient and accurate method is provided for restraining low-frequency oscillation. The restraining effect of the low-frequency oscillation is greatly improved, an operating person can master and evaluate the running status of a power system, timely take measures to improve the running status, make a corresponding emergency pre-arranged plan, and reduce occurrences of subsequent low-frequency oscillation, and therefore the method and system are of great significance in reducing the impact to the power grid and ensuring safety operation of the system.

The invention provides a damping control system optimization method based on damping ratios and phase relative sensitivity, which comprises the following steps of: analyzing the dynamic stability of an interconnected power system according to the damping ratio of each oscillation mode, selecting a related oscillation mode to be analyzed and adjusted according to the magnitude of the damping ratios and generating units, high-voltage DC transmission system and the like with greatest influence; converting the coordinates of a mathematical model expression of a power system stabilizer (PSS) related to the oscillation mode and other damping control systems so as to achieve the purpose of modular angle separation; maintaining the gain of a transfer function unchanged after parameter adjustment by using an equivalent AC (Alternating Current) gain method; and calculating the sensitivity of the damping ratio relative to phase, carrying out oriented optimization design with a clear direction onthe parameters of the damping control systems according to the sensitivity, increasing the damping ratio of the oscillation mode, and inhibiting the occurrence of low-frequency oscillation. By means of the damping control system optimization method, the blindness that the parameters of the damping control systems are tried and made up by using an approximate method in the prior art is avoided, and the stable operation of a large interconnected power system is facilitated.

The invention discloses a power-system stabilizer parameter optimization and setting method based on a particle swarm optimization algorithm so that through setting of full-frequency-band and set-frequency-band phase constraint conditions and optimization goals, parameter optimization and setting of common power system stabilizers of PSS2A and PSS2B types can be carried out. The method uses zero-compensation frequency characteristics of an actual measurement generator excitation system and sections of local oscillation frequency points as a basis and has an excellent restraint effect on oscillation of different kinds of hydro-thermal generators, especially bulb tubular turbines in a comparatively wide frequency range and in a specific frequency range. Power system stabilizer parameters which are set through use of the method are capable effectively playing roles in improvement of power grid dynamic stability and restraining of low-frequency oscillation of a power system.

The invention discloses a power system stabilizer design method suitable for a double-fed draught fan, and belongs to the technical field of the automatic control of new energy power systems. According to the technical scheme, firstly, nodes and lines of the whole network are numbered uniformly to build a system parameter list; secondly, a double-fed draught fan augmented correlation measuring module is built; thirdly, power system stabilizers under all selected operating points are designed; finally, the module switching weight value is computed and the output of a controller is obtained. The output control signals of the system stabilizers are superimposed on traditional system control signals, the traditional operation habits can be kept, and the advantages of being simple to achieve, low in cost are achieved. By the adoption of the power system stabilizers designed according to the method, the disturbance resisting ability and the fault ride-through ability of the wind farm can be improved, the stability of the power grid is improved, and the wind power using ability of the power grid is improved.

The invention discloses an optimization method of phase compensation link time constants of a power system stabilizer. The optimization method comprises the following steps of (1) measuring non-compensation phase-frequency characteristics of a unit excitation system by adopting a dynamic signal analyzer on the spot and reading a phase angle within a range of 0.1-2.0Hz; (2) converting the power system stabilizer into the PSS of a rotating speed deviation single-input mode according to structure characteristics of an electric power and rotating speed deviation double-input signal of a PSS4B-W; and (3) building a parameter optimization model of the PSS4B-W by employing third-order lead-lag phase compensation link time constants of the PSS4B-W as optimization variables and in-phase additional moment generated by the PSS and [delta]omega shaft as an optimization target and solving the time constants through an adaptive weight particle swarm optimization algorithm. According to the optimization method, optimized parameters, meeting the industry standard requirements, of the PSS4B-W can be quickly and efficiently found out.

The invention discloses a PSS (Power System Stabilizer) switching based synchronous generator excitation control method. A synchronous generator comprises a prime motor, a generator and an excitation regulator, wherein the excitation regulator is provided with a power system stabilizer; the control method comprises the steps of: step 1, setting a soft switch module in a PSS model of the power system stabilizer to enable the power system stabilizer to be switched between a PSS1A model and a PSS2A/PSS2B model; step 2, detecting an on/off state of a power adjusting joint of the prime motor in real time; step 3, controlling the soft switch module based on the on/off state to enable the soft switch module to be switched off and enable the power system stabilizer to run according to the PSS1A model when the power adjusting joint is in an off state, and enable the soft switch module to be switched on and enable the power system stabilizer to run according to the PSS2A/PSS2B model when the power adjusting joint is in the on state. The PSS switching based synchronous generator excitation control method has the advantages of PSS1A and PSS2A/PSS2B.

The invention provides a boost horsepower type power system stabilizer based on potential frequency in a generator. Adoption of double input signal boost horsepower consisting of generator shaft speed and active power is an effective measure to solve generator reactive power 'contra harmony', but a rotating speed signal is difficult to be measured; a torsion frequency block filter is adopted to avoid shafting torsional oscillation. In the invention, potential frequency in the generator calculated by line voltage and current of the generator is used to replace the generator shaft speed, as variation of the generator shaft speed is the same as the variation of potential frequency in the generator. Potential Eq in the generator can be calculated by measuring voltage U of the generator and current I of a stator, therefore, the generator shaft speed can be obtained by calculating the potential frequency in the generator so as to solve the problem that the generator shaft speed is difficult to be measured without attaching an active power inverter and a rotating speed inverter.

The invention discloses a mixed smart control method of a power system multi-stabilizer. The method comprises the following steps of: establishing neural network prediction models respectively for different stabilizers; predicting the control effects of the stabilizers on line through the neural network prediction models; screening according to the matching degree of the prediction value and the actual rotation speed; carrying out weighted processing on two controllers with better prediction effects so as to obtain mixed control signals; and controlling the operation state of a power generator by taking the mixed control signals as auxiliary input signals of an automatic excitation regulator. The mixed smart control method of the power system multi-stabilizer provided by the invention has the beneficial effects that the control strategy is flexible, and the performances and characteristics of the stabilizers are fully utilized, thus the system achieves the better operation effect; the defect that an adopted single linear lead-lag power system stabilizer is difficult to be adaptive to large-disturbance post-nonlinear characteristic is overcome, ideal damping control is provided, and the transient state transition time and vibration times are reduced; and the mixed smart control method of the power system multi-stabilizer has favorable comprehensive dynamic property and higher robust property, and the stability of the system under each type of disturbance is improved obviously.