37results about How to "Improve disturbance suppression ability" patented technology

The invention relates to a disturbance suppression system and method based on the combination of a model inverse structure and a multi-ring frequency division disturbance observer. The control system based on model inversion and disturbance observer enables the distributed power generation to actively participate in the active power frequency modulation and reactive power voltage regulation process of the power system, and at the same time obtain the reference value of voltage and current; the voltage and current controller finely adjusts the injected voltage and current. The invention can effectively enhance the reliability of the inverter control system, improve the stability, and enable the microgrid to avoid current changes and load power fluctuations caused by loop switching when the microgrid switches the operating mode through the static switch, and realizes the smooth operation mode of the microgrid switch.

The invention discloses a single-accelerometer-based disturbance observation compensation control method of a fast steering mirror. In the prior art, the fiber-optic gyroscope employed by the fast steering mirror commonly has disadvantages of large size, high mass, high price, and high power consumption; and the inner-ring intermediate-low-frequency disturbance suppression capability of the exiting accelerometer is low because of low-frequency noises and the fiber-optic gyroscope can not be replaced. With the single-accelerometer-based disturbance observation compensation control method, the above-mentioned problems can be solved. According to the method, on the basis of acceleration feedback, a disturbance observer is added into an acceleration inner ring for feedforward processing; and the disturbance torque from the outside on the platform is observed and the is fed forward to an acceleration controller, thereby realizing disturbance compensation, enhancing the capability of the accelerometer, and improving the intermediate-low-frequency disturbance suppression capability in the system. The system is optimized in terms of sensor usage mode; the capability of the accelerometer sensor is utilized fully based on combination of feedback and feedforward; characteristics of large bandwidth, small size, low mass, and low price of the accelerometer are exploited; and the space and cost are saved.

The invention discloses a vibration suppression method of a tilted mirror based on an improved repetitive controller, which is inserted into a tilted mirror system to suppress the vibration. As a learning strategy, repetitive control can enhance error attenuation and achieve optimal correction to system disturbances when the frequency of system disturbances is known. Aiming at the problem that the traditional repetitive control method will amplify the disturbance at non-periodic frequency, the present invention proposes an improved repetitive controller to optimize the control algorithm, which will not cause other disturbances on the basis of improving the system disturbance suppression ability. Amplification of frequency disturbances. In addition, the method only needs one image sensor, and the cost is low. At the same time, its structure is simple, independent of the model, easy to operate and implement, and does not cause a compromise between vibration suppression and noise transmission.

The invention discloses a disturbance suppression method based on a composite disturbance observer, aiming at the problem that the low-frequency and medium-frequency disturbance suppression ability of the stable platform of the control system is insufficient and cannot meet the requirements of a higher-precision stable control system. On the basis of multi-closed-loop control, this method improves the traditional disturbance observer design, proposes a composite disturbance observer structure, and gives the design method of the inner and outer loop feedforward compensation controllers in the composite disturbance observer. The present invention utilizes the outer loop in the composite disturbance observer to estimate and reverse-phase feed-forward the middle frequency band and the external disturbance, and utilizes the inner loop to estimate and reverse-phase feed-forward the low-frequency band and the external disturbance, so that the inner and outer loops of the composite disturbance observer Simultaneously, the purpose of improving the disturbance suppression capability of the low-frequency band and the mid-frequency band of the system at the same time is finally achieved, and the stability and accuracy of the control system are improved.

The invention discloses a digital control method of a two-stage three-phase three-level photovoltaic grid-connected inverter. According to the method, a bus voltage outer ring, a d-axis capacitance current inner ring and a q-axis grid current inner ring are combined to control a three-level inverter. To solve the problem that a bus voltage control dynamic condition is slow in an exiting control mode, inverter grid-connected current and a modulation ratio are used for calculating equivalent bus capacitance current, a bus capacitance current loop is used for controlling SVPWM reference vectors of the inverter, input impedance of the inverter is reduced, inhibiting ability of bus voltage on disturbance caused by changes of power of photovoltaic cells is improved, and the capacitance value of a bus capacitor is lowered. By means of the method, a thin-film capacitor with small capacitance value and high reliability can be adopted in the inverter, and reliability of the inverter is improved.

The invention discloses a dual-frame MSCMG frame system high-precision control method based on self-adaptive sliding mode compensation. Firstly, a dual-frame servosystem kinetic model is established; Input and output inverse mapping of a frame system is derived in a differential geometry approach, and then a a pseudo-inverse system of a frame system is obtained so as to realize kinetic decoupling control of the frame system and eliminate influences by coupling moments between frames; then on the basis of a differential algebraic spectrum theory, a tracking error stable control law is derived so as to enable the frame system to have certain response characteristics and guarantee the stability of the frame system; and finally, on the basis of an RBF neural network and a sliding mode control theory, a self-adaptive sliding mode compensation controller is designed to carry out compensation control on residual coupling, involved toques and nonlinear friction to enhance the disturbance inhibition ability of the frame system to realize high-precision angular rate tracking control of the dual-frame system. The method of the invention is simple and is simple to implement. The method is applicable to high-precision decoupling control of the dual-frame Magnetically Suspended Control Moment Gyroscope frame servosystem.

The invention discloses a double-filter disturbance observer design method for a non-minimum phase system, which is used to solve the problem that the traditional disturbance observer method is unstable in the non-minimum phase system and cannot suppress disturbance. The present invention introduces a forward model, and provides a new disturbance observer frame structure and a double filter design scheme. The invention starts from the frame structure of the new disturbance observer, carries out stability constraints on the double filter, and analyzes the tracking characteristics and disturbance suppression characteristics of the system under the premise of ensuring the stability of the system. The filter one in the present invention adopts the design of the original closed-loop controller, and the filter two is designed according to the filter one, and realizes the same performance as the filter one. On the basis of not changing the tracking characteristics and stability of the closed-loop non-minimum phase system, the invention can use any filter alone to double the disturbance suppression capability of the system, and use dual filters at the same time to improve the disturbance suppression capability of the system. twice as high.

The invention discloses a disturbance decoupling and suppression method based on the fusion of gyro and fine TV signals. The azimuth axis and the pitch axis of the photoelectric tracking system are respectively loaded with angular rate gyroscope A and angular rate gyroscope E, and the gyroscope signal is used for coarse The velocity loop of the tracking loop is closed, in addition, the high frequency part of the decoupling gyro signal is the high frequency part of the disturbance signal. The precision TV is installed inside the rack, and the target deviation is detected by the fast mirror. The precision TV signal is used for the closed loop of the precision tracking loop. At the same time, the low-frequency signal of the precision TV is decoupled and the decoupled gyro signal is fused and fed forward to the precision tracking loop, which can improve the performance. The ability of the system to suppress disturbances, but does not affect the system's target tracking ability, to achieve precise and stable control. The present invention does not need to add additional sensors, and does not need to establish an equivalent model of the control object. The structure is simple, which is beneficial to the realization of the project.