63 results about "Plus integral" patented technology

The invention provides a maximum power tracking control method of a voltage variable photovoltaic system which adapts to weather conditions, belonging to the photovoltaic power generation technical field; firstly, three data of voltage, current outputted by a photovoltaic battery and temperature of a photovoltaic battery plate at a moment are collected by a collection circuit, and an open circuit voltage value and an illuminating value at the moment are worked out based on the collected data; secondly, an approximate optimum output voltage value is obtained by a real optimized voltage coefficient multiplying the open circuit voltage value, and the temperature and the illumination are compensated, which obtain a real optimum output voltage value, and further a real optimum output current value is obtained; thirdly, an output value of a load end is compared with the real optimum output voltage value and the real optimum output current value, and a maximum power output is realized based on the proportional plus integral control on a fluctuating chopper circuit and a double closed loop of the voltage and the current. The maximum power tracking control method of the voltage variable photovoltaic system improves the output power of a photovoltaic power generation system and simultaneously ensures the operational stability and reliability of the system.

The invention provides a maximum power point tracking method based on efficient adaptive perturbation and observation. By the aid of the maximum power point tracking method, the problem that the step size used in a traditional perturbation and observation method in the photovoltaic-battery maximum power point tracking technology is difficult to balance, completely adaptive perturbation can be realized, and tracking speed, stability precision and universality of a system are high. The maximum power point tracking method with a basic principle includes that computing continuous output power values of a photovoltaic array according to filtered voltage and current signals; generating error signals according to changes among power signals; generating adaptive perturbation voltage values via a PI (proportional plus integral) controller; and finally generating a reference value of voltage of the photovoltaic array according to the basic principle of perturbation and observation. An error signal of an actual value and the reference value of the voltage of the photovoltaic signal is computed, and a duty cycle signal d required by a DC / DC converter is generated by another PI controller, so that on and off time of each power switch tube of a phase-shift full-bridge converter is controlled, power outputted by the photovoltaic array is adjusted, and the maximum power output point of the photovoltaic array can be tracked.

The invention discloses a microgrid layered and synchronous control method. The microgrid adopts the double-perturbation synchronous control strategy based on the Fourier transformation to perform synchronous grid connection. In the case of island or grid-connection model of the microgrid, microgrid PCC (point of common coupling) frequency and voltage amplitude is detected by SFR-PLL (synchronous reference frame-phase-locked loop), and by the use of a PI (proportional plus integral) controller of a recovery control loop, zero-error tracking of the microgrid PCC frequency and voltage amplitude to a target frequency and voltage amplitude is achieved. As the microgrid transforms from the island model to the grid-connection model, frequency correction is added in the second-layer control of the microgrid, phase and voltage amplitude are subjected to perturbation control, voltage differences of two sides of a grid-connection switch are performed with the Fourier transformation, the perturbation and observation method is employed to allow the two-side voltage phases and amplitudes synchronous, current shock of a close grid-connection switch to the microgrid is restrained, seamless switching is realized during model transformation, smoothness is improved during the transition process, and guidance is provided for large-scale renewable energy system connection.

A method for controlling a dynamic response of a fuel control valve in a gas turbine fuel control system is provided. The method includes regulating a fuel supply pressure for a gas turbine using a component model, sensing a pressure of a fuel supply to the gas turbine, and applying a proportional plus integral control algorithm combined with a gas supply pressure feedforward signal to a pressure command signal controlling the fuel control valve to increase a system response in rejecting a pressure disturbance and increase a disturbance rejection bandwidth of a fuel control valve response.

The invention discloses a neutral network theory-based non-linear system adaptive proportional integral control method. The method comprises the following steps: in a first step, a mathematical model for a non-linear system is built; in a second step, a smooth function is used for approximating a non-smooth performer saturation function; in a third step, a neutral network adaptive proportional plus integral controller is designed for control. According to the method disclosed in the invention, as for a non-linear system with input saturation, the smooth function is used for approximating the performer saturation function, a BLF is referenced, that neutral network input is maintained in a bounded compact set range can be ensured, and normal operation of a neutral network can be ensured; compared with a conventional PI gain adjustment, an adjustment method put forward in the invention is advantageous in that 1) proportion integral gain of the PI controller is not a fixed constant but a time variant; 2) proportional gain and integral gain are not designed individually but associated with each other via a certain coefficient, and therefore system analysis can be facilitated; 3) the method has certain robustness for nondeterminacy and input saturation of the system.

The invention provides an engine cooling system control method and system and a vehicle. The control method comprises the steps of acquiring the actual water temperature, rotating speed and load of anengine, determining the target water temperature of the engine according to the rotating speed and the load of the engine, calculating the deviation value of this time between the target water temperature and the actual water temperature and obtaining the deviation change rate according to the deviation value of this time and the deviation time of last time, obtaining a feed-forward signal used for adjusting the opening degree of a ball valve according to the target water temperature, determining a proportional plus integral control feedback signal for adjusting the opening degree of the ballvalve according to the deviation value of this time and the deviation change rate, obtaining an opening degree adjusting signal according to the feed-forward signal and the feedback signal and adjusting the opening degree of the ball valve according to the opening degree adjusting signal. By means of the engine cooling system control method, rapid and accurate control over the water temperature of the engine can be realized; and accordingly, the performance of the engine is improved, and duel consumption is reduced.

The invention discloses a method of controlling a three-phase inverter and a device thereof. The device comprises a three-phase three-leg inverter bridge consisting of six power switch tubes, an output filter circuit including a three-phase filter reactor and a three-phase filter capacitor and a main circuit consisting of a three-phase boosting / decompression isolation transformer Delta / Y; a load voltage is processed through phase-separation PI proportional plus integral control; the three-phase inverter is led to keep the balance of three-phase output voltage under any linear or nonlinear unbalanced load. When in unbalanced load, symmetrical output voltage of the three-phase inverter, the equivalent three-phase magnitude, orthoscopic voltage waveform and high output voltage quality can be kept all the time, and the load is enabled to work normally.

The invention discloses a control method of a self-balancing man-riding electric unicycle. The method includes: acquiring data from an accelerator and a gyroscope disposed on the unicycle, subjecting the acquired data to Kalman filtering to obtain current tilt angle and tilt angular velocity of the unicycle, acquiring a given motor speed value through a nonlinear PD (proportional plus derivative) controller, acquiring a given torque current value from a difference between the given motor speed value and a currently measured motor speed fed-back value through a PI (proportional plus integral) controller, acquiring a drive signal through vector control, and allowing a motor to output a proper torque to keep the unicycle balanced. The control method has the advantages that a control strategy features good dynamic and static properties, system vibration and noise are reduced, and the unicycle is allowed to self-balance the attitude and to carry a man riding.

A method of measuring a motor constant is provided in a vector control apparatus for an induction motor. A voltage output phase θv is set at a previously set arbitrary phase. Prior to applying a current, a current command is fed to operate the vector control apparatus with a proportional-plus-integral controller being set operative. After conduction for a predetermined time, the gain of the proportional-plus-integral controller is set to zero to maintain an integrated value constant and accordingly fix a voltage command value. In this state, a current command value and a detected current value are measured. This measurement is performed at two levels of current, and a primary resistance value (or a line-to-line resistance value) is derived from the slope.

The invention discloses a stabilization control method of a VSC-HVDC power transmission system. The stabilization control method comprises a virtual resistance-inductance impedance stabilization control part, an output current feedforward control part, and a voltage current double-loop control part According to the virtual resistance-inductance impedance stabilization control, equivalent output impedance of a rectification station converter is corrected to be positive resistance, the damping of the system is enhanced, and the stability of the system is effectively improved, and the direct current side oscillation of the VSC-HVDC power transmission system is inhibited. According to the output current feedforward control, influences of receiving end load power abrupt changes on direct current busbar voltage are reduced, and the transient response performance of the system is improved. A direct current voltage outer ring adopts proportional plus integral control, and is used to track a direct current voltage instruction in an astatic way, and a grid-connected current inner ring adopts feedforward decoupling control under synchronous rotation coordinates, and then relatively low grid-connected current aberration is guaranteed. The stabilization control method is used for the control of the rectification station converter of the VSC-HVDC power transmission system, and the direct current side oscillation of the VSC-HVDC power transmission system is effectively inhibited, and the dynamic performance of the inversion station converter cannot be affected.

The invention discloses an STATCOM current tracking and compensation method. The method includes processing a three-phase voltage and a three-phase current which are gathered at point P, obtaining a transfer matrix as well as active current components and reactive current components of the current which needs to be compensated by a system, processing the current gathered by load side through transformation from a coordinate abc to a coordinate dq and a low pass filter, obtaining direct current components on q axis of the STATCOM reference current, outputting the direct current components as active components of the reference current in the voltage proportional integral cycle of the STATCOM direct current capacitance and voltage, controlling the active components and reactive components of the compensated current through fuzzy proportional plus integral (PI) control, producing control signal through the technique of space vector pulse width modulation (SVPWM), and controlling the output of STATCOM. The STATCOM current tracking and compensation method has the advantages that influence on STATCOM performance caused by asymmetry of the three-phase voltage of the system is overcome, current needed to be compensated by the system is detected accurately, and the current needed to be compensated by the system is tracked and compensated quickly and effectively.

The invention discloses a compound control method of a photovoltaic grid-connected inverter. The compound control method comprises the steps of performing 3s / 2r transformation on input current and establishing a grid-connected inverter model under a d-q coordinate system; and utilizing a compound controller to control output current to eliminate even harmonic component disturbance in the output current, wherein the compound controller comprises a proportional plus integral (PI) controller and a repetitive controller which are connected in parallel. By means of the technical scheme that the 3s / 2r transformation is performed on the input current, and the compound controller composed of the PI controller and the repetitive controller which are connected in parallel is utilized to eliminate the even harmonic component disturbance in the output current, dynamic response of a system is increased, accuracy and stability are high, harmonic component disturbance can be controlled well, steady-state errors can be eliminated, and the grid-connected current control effect is good.

A method of measuring a motor constant is provided in a vector control apparatus for an induction motor. A voltage output phase [theta]v is set at an previously set arbitrary phase. Prior to applying a current, a current command is fed to operate the vector control apparatus with a proportional-plus-integral controller being set operative. After conduction for a predetermined time, the gain of the proportional-plus-integral controller is set to zero to maintain an integrated value constant and accordingly fix a voltage command value. In this state, a current command value and a detected current value are measured. k is measured at two levels of current, and a primary resistance value (or a line-to-line resistance value) is derived from the slope.

The invention relates to a permanent magnet synchronous machine control system based on a high-order sliding mode method. The system is characterized by comprising the components of a Cark transformation module, a Park transformation module, a rotary transformer, a high-order sliding mode observer, a two-order supercoiling sliding mode controller, a first comparator, a second comparator, a permanent magnet synchronous motor d-axis current loop proportional plus integral controller, a permanent magnet synchronous motor q-axis current loop proportional plug integral controller, a Park inverse transformation module, a pulse width modulation module and an inverter. The permanent magnet synchronous machine control system can quickly and effectively adjust various input parameters and output parameters of the permanent magnet synchronous motor on the condition that an interference occurs, and furthermore realizes high dynamic response speed and high robustness. Furthermore the permanent magnet synchronous machine control system improves control precision and operation reliability of the permanent magnet synchronous machine.

The invention discloses a double-resonance injection type broadband impedance measuring device and a control method thereof. The measuring device comprises a current disturbance injection unit, a signal processing unit and a broadband impedance calculation and monitoring unit; each phase of the current disturbance injection unit is cascaded with 6 sub-power module units; the output of each phase of the current disturbance injection unit is connected into a system to be tested through a disturbance injection branch; and the disturbance injection branch combines the advantages of a series resonance branch and a parallel resonance branch, and therefore, a cascade power module can withstand a small fundamental voltage, most of disturbing current is injected into the system to provide a currentdisturbance source. According to a cascaded H-bridge converter, a voltage outer loop adopts proportional plus integral control, and a current inner loop adopts quasi-proportional resonance control; and the turning on and turning off of the power devices of H-bridge converters in each phase are controlled through carrier phase-shift SPWM multilevel modulation. With the control method adopted, thesystem has higher reliability and faster dynamic response and can meet the requirements of the application of the system to megawatt-level high-power conditions and wideband disturbance output impedance measurement.

The invention discloses an oscillator disciplining system for a satellite clock device of a power system, which comprises a digital phase discriminator which takes 1PPS output by a satellite time transfer receiver as a reference to discriminate the phase of 1PPS output by a high-stability crystal oscillator at divided frequency, wherein the digital phase discriminator is connected with a proportional integral controller; the voltage output by the proportional integral controller is transmitted to a pressure controlled control end of the high-stability crystal oscillator; the pressure controlled control end performs the fine adjustment of output frequency; and the high-stability crystal oscillator is connected with a frequency divider. The oscillator disciplining system for the satellite clock device of the power system is reasonable in structure, can eliminate an accumulated phase error and has excellent tracking performance. Due to adopted proportional plus integral control, the 1PPS output by the high-stability crystal oscillator can track the 1PPS of a satellite step by step, and if the 1PPS of the satellite is stable and final phase error is zero. When the 1PPS of the high-stability crystal oscillator locks the 1PPS of a satellite, the frequency of the 1PPS is calibrated.

A servo control system having a proportional (P) or a proportional plus integral (PI) position controller, which output signal represents an input speed reference signal for a speed close loop system with a speed controller detecting a speed deviation, derived from a speed feedback loop, which output signal represents an input current reference signal for a current close loop system with a current controller detecting a current deviation, derived from a current feedback loop, which controls an amount of the current flowing through a motor. The position controller detects the position deviation between a position reference signal and a position feedback signal separately for the P part controller, to produce a P part speed reference signal, and for the I part controller, to produce an I part speed reference signal, as a “two parallel-position outer loop feedback control system” and includes a position reference reduction circuit with scale coefficient less than one for the close loop with the P part controller. The P part controller and the I part controller connect to the summing unit, which sums the P part speed reference signal and I part speed reference signal, and its an output signal represents the speed reference signal for the speed close loop system.

A control device controls opening / closing of a sliding door of a vehicle by a motor in cooperation with a drive device that opens and closes the sliding door, and applies proportional plus integral plus differential control to motor speed based on a driving pattern of the sliding door. When a difference between a door speed and a motor speed exceeds a threshold, the control device judges that the vehicle is parked in a tilted state, and adjusts a sum of a proportional element, an integral element, and a differential element of a proportional plus integral plus differential control to a vehicle-tilted time element.

The invention discloses a predictive control-based permanent magnet synchronous motor composite current control system and method. According to the system and method of the invention, the actual angular speed omega of a motor and the given reference rotational speed omegar of the motor, adopted as variables, are inputted to a PI rotational speed loop control module; the PI rotational speed loop control module calculates the difference of the actual angular speed and the reference rotational speed; by means of the proportional plus integral action of a rotational speed loop, the output currenti<*>q of the module is adopted as a q-axis reference current value; the three-phase output current of the motor is subjected to Clark transformation, the current of the motor in a two-phase stationaryalphabeta coordinate system is obtained, and the current is subjected to Park coordinate transformation, so that two-phase current under a dq rotating coordinate system is obtained; and reference current under a motor dq coordinate system and the two-phase current under the dq rotating coordinate system are inputted to a predictive current controller. According to the system and method of the invention, deadbeat predictive control and equivalent interference input are adopted. The current controller of the method can be applied to a PMSM torque or rotational speed driving system, has high current tracking performance and can quickly adjust the system when the system is subject to disturbance, so that the system will not be affected by a variety of disturbance factors.

The invention discloses a control device of an induction motor, comprising a tri-phase bridge rectifier, a power module, the induction motor, a current transformer, a coder, a pulse-width modulation (PWM) driver and a driving operating system, wherein the driving operation system adopts a vector control mode and comprises a filter circuit which is connected between a speed loop proportional plus integral (PI) controller and an exciting current instruction operation unit of the driving operation system and is used for filtering the moment current instruction value and inputting the filtered moment current instruction value in the exciting current instruction operation unit; and the exciting current instruction operation unit corrects the exciting current instruction value Ids of the induction motor based on the filtered moment current instruction value to lead the induction motor to have the minimum total current under the same load condition. The invention also discloses an application of the control device of the induction motor. In the invention, on the premise of not weakening the heavy load driving capacity of an escalator and a moving walk, the effect of stable operation of the motor with minimum current under a medium / light load condition is realized, thus achieving energy conservation.

The single-phase active electric power filter of using analog cascaded controller includes control circuit, and connected main circuit. The control circuit includes first and second proportional plus integral controllers, multiplier, subtracter, feedforward controller, and adder. Principle of the invention is as following: using voltage loop composed of these analog parts adjusts DC voltage of bus in two control loops including external current loop as well as generates current of reference power supply; using current loop reduces interference effect, and tracks current of reference filter; finally, generating command signal for main circuit to generate compensating current. Using analog devices in low cost without need of microprocessor, the invention realizes active electric power filter capable of restraining harmonic, and correcting power factor. The invention reduces cost of the filter, and has no mathematic burden for calculating fundamental wave and harmonic of load current.

An exemplary temperature control system for animal confinement buildings includes an agricultural heater and a ventilation system. The agricultural heater is modified to be a variable rate heater using SmartBox technology or by applying appropriate control logic and outputs to a conventional room controller. A heat on / off relay of the room controller can serve as an enable signal connected to the SmartBox. Heating is controlled using a proportional-plus-integral algorithm for error correction. Error correction may be ceased when temperatures fall within a dead band. Heat is turned on when the temperature drops to an on temperature equal to a set point minus 0.5 F. Heat can be turned off when the heater has been at a minimum output level for a minimum output period (such as 90 seconds) and the temperature has not dropped below the on temperature during the minimum output period. An auto-variable radiant brooder may be incorporated.

The invention discloses a valve-controlled cylinder electro-hydraulic position servo system low-frequency interference compensation method. The valve-controlled cylinder electro-hydraulic position servo system low-frequency interference compensation method comprises the steps that a position command signal r is input; a pressure difference signal p of two cavities of a hydraulic cylinder and an acceleration signal a of a piston rod of the hydraulic cylinder are used as input signals of a disturbing force calculation module to obtain the disturbing force F; the disturbance compensation signal x2 is calculated; the position command signal r is used for subtracting the a displacement signal c of the piston rod of the hydraulic cylinder, and the difference between the position command signal rand the displacement signal c are used as input signals of a proportional plus integral controller; an output signal x1 of the proportional plus integral controller is added to a disturbance compensation signal x2 to obtain a drive signal x of a servo valve, and the drive signal x is input to a valve-controlled cylinder system to drive the hydraulic cylinder and the load to generate the corresponding movement. According to the valve-controlled cylinder electro-hydraulic position servo system low-frequency interference compensation method, the fluctuation of the amplitude-frequency characteristic of closed loop transfer function of system location within the 6-7hz band can be reduced to within 3dB, and control precision of the system is significantly enhanced. The valve-controlled cylinderelectro-hydraulic position servo system low-frequency interference compensation method is easy to realize by computer numerical control.

The invention relates to a system for proportional plus integral control in an air separation energy saving process, which comprises a field intelligent instrument and a DCS system which are directly connected with an air separation tower, wherein the DCS system comprises a storage device, a control station and an upper computer, the field intelligent instrument is connected with the storage device, the control station and the upper computer, the upper computer comprises a proportional plus integral controller for solving control law output operation variable values, and the proportional plus integral controller comprises a component inferring module and a proportional plus integral control law solving module. The invention also provides a method for proportional plus integral control in an air separation energy saving process. The invention can effectively and quickly track the change of set values in the air separation energy saving process, and can establish a proportional plus integral control scheme with simple structure and high-efficiency control based on the condition that a control model in the air separation energy saving process can be easily subject to model mismatch.

A powertrain includes a torque generative device and a torque converter having an impeller, a turbine and a torque converter clutch. A method to control torque converter slip includes a feedforward component and a feedback component. The feedforward component includes monitoring a reference slip, and actual slip, and a turbine speed of the torque converter, determining a desired turbine torque based upon the reference slip and the turbine speed, determining an actual turbine torque based upon the actual slip and the turbine speed, determining a feedforward torque converter clutch pressure command based upon the desired turbine torque, the actual turbine torque, a torque generative device torque, and a TCC gain, and determining feedforward torque converter clutch pressure command. The feedback component modifies the feedforward command pressure based on proportional plus integral plus differential (PID) slip feedback terms.

In a fuel injection control system for an internal combustion engine provided with a low pressure fuel pump and a high pressure fuel pump, proportional plus integral control of a high pressure fuel pump is carried out to make a pressure of fuel come close to a target value between the high pressure fuel pump and fuel injection valves. In cases where the high pressure fuel pump is in operation, a feed pressure, which is a pressure of fuel between a low pressure fuel pump and the high pressure fuel pump, is caused to go down when an integral term in the proportional plus integral control does not change or is decreasing, and the feed pressure is caused to go up when the integral term is increasing. In cases where the high pressure fuel pump is in a stopped state, the feed pressure is made higher than before the high pressure fuel pump is stopped.

A method for controlling a dynamic response of a fuel control valve in a gas turbine fuel control system is provided. The method includes regulating a fuel supply pressure for a gas turbine using a component model, sensing a pressure of a fuel supply to the gas turbine, and applying a proportional plus integral control algorithm combined with a gas supply pressure feedforward signal to a pressure command signal controlling the fuel control valve to increase a system response in rejecting a pressure disturbance and increase a disturbance rejection bandwidth of a fuel control valve response.

A current control type converter has a converter section and a control section that includes three controllers. A first controller calculates and outputs an active current instruction value by proportional-plus-integral control to perform proportional integration of a deviation between the value of a DC voltage outputted from the converter section and a DC voltage instruction value. A second controller calculates and outputs an active voltage correction value by proportional-plus-integral control to perform proportional integration of a deviation between the active current instruction value from the first controller and the value of an active current inputted to the converter section. A third controller calculates and outputs a reactive voltage correction value by proportional-plus-integral control to perform proportional integration of a deviation between the value of a reactive current inputted to the converter section and a reactive current instruction value.

A current control type converter has a converter section and a control section that includes three controllers. A first controller calculates and outputs an active current instruction value by proportional-plus-integral control to perform proportional integration of a deviation between the value of a DC voltage outputted from the converter section and a DC voltage instruction value. A second controller calculates and outputs an active voltage correction value by proportional-plus-integral control to perform proportional integration of a deviation between the active current instruction value from the first controller and the value of an active current inputted to the converter section. A third controller calculates and outputs a reactive voltage correction value by proportional-plus-integral control to perform proportional integration of a deviation between the value of a reactive current inputted to the converter section and a reactive current instruction value.

An exemplary temperature control system for animal confinement buildings includes an agricultural heater and a ventilation system. The agricultural heater is modified to be a variable rate heater using SmartBox technology or by applying appropriate control logic and outputs to a conventional room controller. A heat on / off relay of the room controller can serve as an enable signal connected to the SmartBox. Heating is controlled using a proportional-plus-integral algorithm for error correction. Error correction may be ceased when temperatures fall within a dead band. Heat is turned on when the temperature drops to an on temperature equal to a set point minus 0.5F. Heat can be turned off when the heater has been at a minimum output level for a minimum output period (such as 90 seconds) and the temperature has not dropped below the on temperature during the minimum output period. An auto-variable radiant brooder may be incorporated.