315 results about "Pid regulator" patented technology

The invention relates to a thermal power generating unit reheated steam temperature controlling method. According to the operating characteristics of the boiler reheater and the theoretic study on a steam-temperature control system, a state feedback control method based on incremental state observer is adopted, and the concept of an algebraically equivalence observer is used to direct the parameter setting of an incremental state observer; in addition, a special control circuit is arranged in the steam-temperature control circuit to resolve the problems that the process of steam-temperature adjustment is relatively long when the reheated steam temperature set value is changed, non-linearity exists during steam-temperature control, the process of steam-temperature variation is very slow, etc., and variation parameter PID regulator is combined to jointly form a comprehensive reheated temperature automatic adjusting system. The invention is capable to ensure reheated steam temperature control to escape spray water upon large-range load variation, and effectively overcomes the disadvantage of the poor effect of the traditional PID regulation on the control of big lagged object; the reheated temperature control effect is improved remarkably; and a sample is provided for controlling the controlled object with big inertia and serious lagging in relation to reheated steam temperature.

A multivariable control system provides regulation for a plurality of control variables of interest based on selecting a particular one of the variables for regulation relative to a corresponding setpoint, while continuing to monitor the other variables and switching regulation control over to another one of the variables as needed to maintain all of them within their allowed ranges. The system includes one or more PID regulators that tune themselves for the particular variables selected for regulation control. In an exemplary embodiment, the control system is configured for controlling an alternative energy system, wherein it includes one or more power flow devices that control power flow between electrical energy storage devices (EESDs) and a common dc bus and/or power flow between the dc bus and an external ac electrical system.

The invention provides a bearingless switched reluctance motor and a control method thereof. The difference between a rotor pole arc angle and a stator pole arc angle of the motor is 15 degrees, current of torque windings and suspension windings are controlled to generate suspension force, the current of the torque windings is controlled so as to generate torque, and current of the torque winding of each phase and turn-on and turn-off angle of the torque winding are regulated to achieve a speed closed loop; radial displacement of a rotor is detection, and radial force needed for rotor suspension is outputted via PID (proportion integration differentiation) regulators, so that closed-loop control of radial displacement of the rotor is achieved. The suspension windings are only excited and conducted in a maximum-inductance flat-top area and do not generate torque, so that the torque and the suspension force can be decoupled in control, and current magnitude of the torque windings and the suspension windings is optimized to make copper loss of the windings to be minimum; in addition, counter potential of the suspension windings and the torque windings is zero in the maximum-inductance flat-top area, and high-speed suspended running of the bearingless switched reluctance motor is benefitted so as to give full play to high-speed adaptability of the switched reluctance motor.

The invention relates to a method for predicting and controlling steam temperatures of boilers on the basis of a state observation model. The method includes 1, replacing heat exchangers by multiple sections of concentration parameter links by a principle of natural segmentation or virtual segmentation, and using outlet parameters of media of various sections as representative parameters of the concentration links to build a mathematical model of enthalpy and temperature channels of the heat exchangers; 2, creating a state observer on the basis of output feedback and estimating outlet temperatures of the various sections; 3, connecting an MPC (multivariate model prediction controller) and a PID (proportion, integration and differentiation) regulator in a cascade manner to form a serial control circuit, acquiring step response coefficients according to the model of the enthalpy and temperature channels of the heat exchangers and acquiring set values of lead temperatures; 4, regulating the steam temperatures by the inner-loop PID regulator according to difference among the lead temperatures and output of the MPC and acquiring control signals of attemperation water valves. The method has the advantages that model building and verification are carried out, so that field test requirements can be reduced; states of inertial and lagged controlled objects are reconstructed via the state observer, so that characteristics of the objects can be modified; prediction and control are implemented, so that targets can be accurately and quickly controlled.

The invention relates to a control method for stabilizing the mixed gas heat value, the method comprises steps that: actual measuring heat values of blast furnace, coke oven and converter gas and the setting values of mixed gas heat values and various gas input amounts are taken as input parameters of a feedforward adjustment control loop, the required coke oven gas flows can be calculated by an energy balance formula; after feedforward adjustment, under the condition that the mixed gas heat value is not still to reach to the setting value, the difference value of the mixed gas actual measuring heat values and the setting values of the mixed gas heat value is taken as the input parameters of a feedback compensation adjustment, the difference value can be adjusted by the PID regulator to implement the compensation adjusting control; finally the coke oven gas flow output can be adjusted by the PID regulator. The invention can effectively control and adjust the mixed gas heat values and greatly improve the heating quality of the heating furnace steel billet.

The invention discloses a control method for an unbypassed booster fan of a desulphurization system. The control method for the unbypassed booster fan of the desulphurization system comprises the following working conditions: when a unit normally runs, an opening command of a moving blade of the booster fan jointly consists of a regulatory signal of a proportion integration differentiation (PID) regulator and a feedforward signal formed by opening of a stationary blade of a induced-draft fan or the total blast volume of a boiler, wherein the feedforward signal serves as input by the opening of the stationary blade of the induced-draft fan or the total blast volume of the boiler and is obtained through an object transfer function which corresponds to the opening of the stationary blade of the induced-draft fan or the total blast volume of the boiler; when runback (RB) is caused to the unit when equipment trips abnormally, the opening command of the moving blade of the booster fan jointly consists of the regulatory signal of the PID regulator and a control signal formed by the abnormally tripping equipment, wherein the control signal serves as input by current unit load and is obtained through an object transfer function which corresponds to the abnormally tripping equipment. Therefore, the control problem of the booster fan of the desulphurization system when the RB occurs on the unit is solved, so that the inlet pressure of the system can be controlled to be within a proper range by the booster fan when the RB occurs on the unit, and the unit cannot trip due to the fact that the pressure fluctuation is high.

The invention discloses a self-adaptive grid-tied converter single phase soft phase-locked loop. The self-adaptive grid-tied converter single phase soft phase-locked loop comprises a phase discriminator, a low pass filter, a loop filter and an integrator module, wherein the loop filter is composed of a self-adaptive moving average filter and a proportion integration differentiation (PID) regulator, the phase discriminator is a multiplication phase discriminator, an input signal is a trigonometric function of an output angle of power grid voltage and a phase-locked loop, and an output signal is transmitted into the moving average filter; an input signal of the moving average filter is output of the phase discriminator and output of the low pass filter, and the output signal is transmitted to the PID regulator; and an input signal of the PID regulator is an output signal of the moving average filter, and the output signal is transmitted into the low pass filter and the integrator module. The self-adaptive grid-tied converter single phase soft phase-locked loop has the advantages that the loop filter is improved, effects of secondary ripple and harmonic voltage on phase lock result in the steady state are eliminated, and simultaneously the rapidity of the phase lock is guaranteed.

The invention discloses a frequency conversion constant-pressure water supply system and a control method thereof. The frequency conversion constant-pressure water supply system is characterized in that a programmable controller and a frequency converter are connected with a PID (Proportion Integration Differentiation) regulator and control a water pump set; and the PID regulator detects water pressure through a pressure sensor. The control method of the frequency conversion constant-voltage water supply system comprises the following steps of: when water consumption is increased, enhancing the working frequency of a water pump, and accelerating the revolving speed of the water pump; when water consumption is decreased, reducing the working frequency of the water pump, and decelerating the revolving speed of the water pump. The invention regulates the revolving speed of various pumps in the living water supply system by adopting the frequency converter and can realize that one frequency converter simultaneously controls multiple water pumps, realize automatic constant-pressure water supply and additionally set a night small pump operating and fire-fighting function.

The invention relates to a thermoelectricity boiler drum liquid level control method, three variables of a drum liquid level, feed water flow and steam flow are taken as processing objects, a feedforward and cascade stage structure is wholly adopted for a control system, a conventional PID adjuster with the drum liquid level as a detecting and controlling variable is adopted for a main adjustor, and the deviation between the set value SP of the drum liquid level and the actual measured value LT is calculated through the PID adjuster and output as the set value of the feed water flow; the measured value of the drum externally supplied steam flow is taken as a feedforward control variable; a single-neuron self-adaptive PSD adjuster with the feed water flow as a detecting and controlling variable is adopted for an auxiliary adjustor. Through the technical scheme, aiming at complex conditions of boiler drum operation, advanced, reliable and practical calculation is adopted to achieve self-adaptive optimum control over the boiler drum liquid level and ensure efficient and stable production of a boiler.

The control method for walking system of spreader includes feeding the rotation speeds of both right and left motor for comparison with the given values, and controlling the rotation speeds via a PID regulator to form a core loop; feeding the speed difference of the right motor and left motor to trace zero target and controlling the speed of one motor via a speed difference PID regulator to constitute a speed difference tracing correction loop; and feeding the accumulated speed difference of the right motor and left motor to trace zero target and further regulate the speed in the speed difference tracing correction loop via a displacement difference PID regulator to form a displacement difference tracing correction loop. All the core loop, the speed difference tracing correction loop and the displacement difference tracing correction loop constitute one closed-loop control system for the walking system of spreader. The present invention has high operation comfortability and high construction quality.

The invention discloses a control method of a permanent magnetic bearing-free synchronous motor non-radial displacement transducer, comprising the steps of: building a model reference self-adapting radial displacement evaluating module by detecting the three-phase voltage and the electric current of a torque control winding and a suspension control winding with the model reference self-adapting theory; evaluating the radial displacement * and * by the model reference self-adapting radial displacement evaluating module; respectively comparing the displacement signals* and * with the reference displacement signals X<*> and Y<*>of a given permanent magnetic bearing-free motor rotor; adjusting with a displacement ring PID adjustor to respectively obtain the given suspending force Fx<*>and Fy<*>of the x axis and the y axis; obtaining the given three phase electric current signals i2A<*>, i2B<*>and i2C<*>for controlling the suspension by means of a suspend decoupling control algorithm; andobtaining real-time controlled three phase electric current i2A<*>, i2B<*>and i2C<*>by adjusting an electric current track type inverter. The control method of the non-radial displacement transducer reduces the cost of the system, shortens the axial length of the bearing-free motor, reduces the volume of the system, and improves the reliability of the system.

The invention is applicable to the servo control filed and provides a servo controller and an electro-fluid servo system. The servo controller comprises a closed-loop control unit used for adopting the PIDF control algorithm to generate driving signals according to the received control signals and feedback signals, a servo valve driving unit used for controlling the movement of an external servo device according to the driving signals generated by the closed-loop control unit, a single chip setting unit used for conducing the parameter setting on the closed-loop control unit, and a power supply unit used for supplying the power to the closed-loop control unit, the servo valve driving unit, and the single chip setting unit. In the invention, the closed-loop control unit adopts the PIDF control algorithm, a PID adjuster is utilized to realize the automatic control gain, the single chip setting unit is utilized to simply, flexibly, and precisely adjust the gain parameters, Therefore, the real-time performance and the interchangeability of the servo controller are improved.

An energy balance-based control method of main steam pressure of a supercritical CFB (circulating fluidized bed) boiler includes the steps: S1, after a main steam pressure deviation signal P<T>-P<TS> of a unit is regulated by a PID (proportion integration differentiation) regulator, a signal A is output; S2: a steam turbine demanded heat signal is acquired through a steam turbine energy demand model; S3, a heat signal provided by boiler energy is acquired through an instant carbon mechanism model; S4, subtracting the steam turbine demanded heat signal E<R> by the heat signal E provided by boiler energy is performed, regulating is performed with the PID regulator, and a signal C is output; S5, after subjected to time differentiation, the steam turbine demanded heat signal E<R> is multiplied by a proportional gain k so as to obtain an output signal B, and a sum of the signals B, A and C is output to a boiler master controller; S6, coal feed is regulated according to master control output of a boiler so as to control the main steam pressure. The method has the advantages that regulating quality of the unit can be improved, stability of a main steam pressure control system of the supercritical CFB boiler is improved and ability to respond to load response of the unit is satisfied.