13 results about "Control variable" patented technology

A method and apparatus for LCL resonant converter control utilizing Asymmetric Voltage Cancellation is described. The methods to determine the optimal trajectory of the control variables are discussed. Practical implementations of sensing load parameters are included. Simple PI, PID and fuzzy logic controllers are included with AVC for achieving good transient response characteristics with output current regulation.

The present invention provides a steel cooling control simulation system and method. A process control device is connected with cooling equipment simulation device, the cooling equipment simulation device includes a transmission fixed with steel bar, a cooling course temperature calculating device simulating the temperature measurement and a patrol demonstrator, an electric potentiometer, a photoelectric switch and a position locator for temperature display, the photoelectric switch is provided on the operation path of the steel bar. The course control device completes the optimization setting function to PLC control variable, PLC completes the real-time control function of the cooling simulation course, the cooling equipment simulation device executes the real switch and adjustment action of the simulation cooling line, and achieving the real-time data collection course. The cooling control course system is simulated by the hardware connection of each device and software cooperation, providing a pilot test device of simulation evaluation in order to improving and completing the control system.

A system and method for determining satisfiability of a bounded model checking instance by restricting the decision variable ordering of the SAT solver to a sequence wherein a set of control state variables is given higher priority over the rest variables appearing in the formula. The order for control state variables is chosen based on an increasing order of the control path distance of corresponding control states from the target control state. The order of the control variables is fixed, while that of the rest is determined by the SAT search. Such a decision variable ordering strategy leads to improved performance of SAT solver by early detection and pruning of the infeasible path segments that are closer to target control state.

Operating a self-igniting internal combustion engine includes: specifying a setpoint combustion position and a setpoint combustion noise feature; operating at least one cylinder of internal combustion engine for at least one cycle while maintaining a first injector control variable and/or an air valve control variable and a second injector control variable and/or a second air valve control variable; ascertaining actual combustion position and actual combustion noise feature of the at least one cylinder; comparing the actual combustion position to the setpoint combustion position and, in case the actual combustion position deviates from the setpoint combustion position, determining anew the first injector control variable and/or the air valve control variable; and comparing the actual combustion noise feature to the setpoint combustion noise feature and, in case the actual combustion noise feature deviates from the setpoint combustion noise feature, determining anew the second injector control variable and/or the air valve control variable.

The invention discloses a control method for a VIENNA rectifier of an aviation multi-electric engine. The control method comprises the following steps: establishing a stationary coordinate system of the VIENNA rectifier and obtaining a mathematical model under a two-phase rotating coordinate system by coordinate transformation; taking a DC side voltage as a control variable, and designing a sliding mode surface based on a global terminal sliding mode theory to design a voltage external loop controller; and taking the DC side voltage and a derivative thereof as input of fuzzy reasoning, and adjusting the sliding mode reaching law in real time according to the output sliding mode in a system state so as to control the DC side voltage. According to the control method disclosed by the invention, the robustness of the system can be improved by virtue of the global terminal sliding mode theory and an error is restrained to be zero within a definite time; the sliding mode reaching law is controlled in real time according to the experience of an expert by virtue of a fuzzy reasoning theory, so that not only is the quickness of system response improved, but also buffeting is effectively weakened.

The invention discloses a method for optimizing fuel cell performance based on frequency and a secant angle. The method comprises the steps that in the working condition of the optimal temperature and humidity at which the total internal resistance Rstack of a PEMFC is minimal, the internal resistance of each galvanic pile segment at the moment is measured, and the ideal high-frequency corner frequency f<optimal> and ideal secant angle alpha<optimal> of different electric current densities are acquired correspondingly; with the f<optimal> and the alpha<optimal> as optimization indexes, focusing on the galvanic piles in any working condition, it is only necessary to emit two frequency signals of the highest frequency (20 KHz) and the ideal corner frequency f<optimal> to monitor the current alpha angle, and through uninterrupted adjustment of relevant control variables, the current alpha angle is changed and tends toward the optimal angle alpha<optimal>, so that the galvanic piles are adjusted to the optimal working state. According to the method, improvement is conducted on traditional EIS methods, and the total internal resistance Rstack is quickly calculated by means of a simultaneous equation solution method; not only is optimization of the galvanic pile output performance of the PEMFC achieved from the internal resistance angle, but also the defects that by means of the traditional EIS methods, the hysteresis is large and real-time detection cannot be conducted are overcome, and operation is simpler and the optimization performance is better compared with traditional methods.

A method of controlling an air separation plant and a control system to optimize production of an argon product produced by the plant. A computer program is continually executed that has models of each column of the plant, a condenser reboiler and an argon reflux condenser. The models contain stage models of each stage of separation within each of the columns that when assembled are able to calculate current values of controlled variables in response to input variables applied to the models. The controlled variables serve as an input to a controller that controls manipulated variables comprising flow rates of an air feed stream to the air separation plant, a product oxygen stream removed from the lower pressure column and the crude argon feed stream such that the controlled variables are within a targeted range selected to optimize the production of the argon product.

The invention discloses a maximum power output control method suitable for controlling a variable speed wind turbine group through concentrated variable flow. According to n wind turbines which are controlled by the same converter in a concentrated mode and are constant in rotating speed and different in input air speeds, the concentrated converter and overall wind turbine propeller pitch variation mechanisms are controlled in a coordinated mode, and therefore maximum power output of the wind turbine group is achieved. A control objective of the concentrated converter is that the speed of the wind turbine with the higher wind speed approaches to the optimal rotating speed as much as possible and a control objective of the propeller pitch variation mechanisms is that the highest wind energy utilization rate of the wind turbine with the lower wind speed is obtained at the unified rotating speed of the wind turbine group. The optimal calculation method is adopted and the frequency conversion alternating current bus frequency and the overall wind turbine propeller pitch angle which correspond to the maximized output power of the wind turbine group are worked out. The maximum power output control method is suitable for the variable speed wind turbine group controlled by an AC-DC converter in a high-voltage direct current power transmission system and an AC-AC frequency converter in a frequency division power transmission system.

The invention relates to a forecast model-based DC power spring control method. The forecast model-based DC power spring control method comprises the steps of S1, obtaining an inductance current reference value of an LC filter according to a main circuit topological structure of a DC power spring main; S2, obtaining a discrete forecast model of the DC power spring according to a switch state simplification model of the DC power spring; S3, building a target function taking an inductance current of the LC filter as a control variable; S4, solving the target function by combining the inductancecurrent value of the LC filter and the discrete forecast model, and obtaining optimal solution of a switch state of the DC power spring; and S5, controlling a switch tube in a single-phase DC/DC converter to be switched on and switched off according to the optimal solution of the switch state of the DC power spring. Compared with the part art, the forecast model is utilized, the target function taking the inductance current as the control variable is built, the switch state of the DC power spring is corrected according to real-time information, and the forecast model-based DC power spring control method has the advantages of simple algorithm and high robustness.