112 results about "Dual loop control" patented technology

The invention relates to a position / force hybrid control method for a space manipulator, which is a double-loop control method combining a Cartesian space and a joint space. Compared with a conventional control method on the basis of an integral model, which has the problems of oscillation of the transition process and algorithm complexity, the position / force hybrid control method for the space manipulator has the advantages that the position / force hybrid control problem is decomposed into the planning problem of the Cartesian space and the control problem of the joint space; a position / force kinematic plan from the Cartesian space to the joint space and kinematic control of the joint space are given out; an internal and external loop control system is formed; and position control on a free space at the tail end of the manipulator and contact force control in a space restrained by the environment are implemented. A simulation result for a SDOF ( Seven Degrees of Freedom) redundant manipulator proves that the method disclosed by the invention is simple to operate, is effective and is easy for engineering realization.

A method of and apparatus for achieving dynamic robot accuracy includes a control system utilizing a dual position loop control. An outer position loop uses secondary encoders on the output side of the gear train of a robot joint axis, while the inner position loop uses the primary encoder attached to the motor. Both single and dual loop control can be used on the same robot and tooling axes.

The invention relates to an air-oil co-production device and method adopting fluidized bed pulverized coal gasification and solid heat carrier pyrolysis coupling. The high-temperature circulating semicoke of a fluidized bed pulverized coal gasifier adopts two-loop control, one loop enters a pyrolysis reactor to be used as heat carrier for performing pyrolysis with coal and forming semicoke, the formed semicoke enters the fluidized bed pulverized coal gasifier; and the other loop directly returns to the return fluidized bed pulverized coal gasifier. The invention is based on the fluidized bed pulverized coal gasification technology, uses the high-temperature circulating semicoke as heat carrier to pyrolyze raw material and generate pyrolysis coal gas and tar before sending raw material to the coal furnace; and the semicoke generated through pyrolysis returns the fluidized bed pulverized coal gasifier for further burning and gasifying, thus raw gas can be produced and air-oil co-production can be realized. The problems such as low process heat efficiency of the traditional solid heat carrier can be overcome, thus the method of the invention is better than the traditional solid heat carrier technology.

A control method for drying tobacco shreds features use of dual-loop control and two control modes. After the upper and lower temp limitations of cylinder wall are set up by system, the temp of cylinder wall is regulated for automatically controlling the content of water in tobacco shreds. After the temp of cylinder wall is fixed, the flow of hot-air is regulated to control the content of water in tobacco shreds. Otherwise, after the upper and lower limitations of the flow of hot air ar set up, the flow of hot air is regulated to control the content of water in tobacco shreds or after the flow of hot-air is fixed, the temp of cylinder wall is regulated to control the content of water in tobacco shreds.

The invention relates to an improved droop control based microgrid auxiliary master-slave control method. The method is used for maintaining stability of the voltage and power of the microgrid. The microgrid comprises multiple DGs connected with alternating current buses respectively; each DG comprises a master-control DG, an auxiliary DG and a slave-control DG; the master-control DG and the slave-control DG are used as a master-control unit and a slave-control unit in the master-slave control method respectively; the inverter in the auxiliary DG adopts voltage and current dual-loop control; a load current io is multiplied by a dynamic virtual impedance Zvir, and the obtained product is used as an instruction voltage to be added in a feedback signal to a voltage loop, so that the output impedance of the inverter is sensitive. Compared with the prior art, the inverter of the auxiliary DG adopts the dynamic virtual impedance, so that matching between the output impedance of the inverter and the circuit impedance can be ensured, voltage drop can be effectively relieved, and the power quality is ensured; and in addition, the improved droop control is adopted, and an integral link is introduced in the reactive power control link, so that steady state voltage without static errors is realized, and the steady state performance of the system is improved.

The invention discloses a rotor-position sensor doubly salient motor system and a control method thereof, belonging to the field of doubly salient motor systems and the control method thereof. The system consists of a doubly salient motor, an excitation winding, a main power circuit and a control circuit, wherein, the main power circuit comprises a power supply and an IPM; and the control circuit comprises an isolation circuit, a failure detection circuit, a three-phase current sampling circuit, an excitation current sampling circuit, a PWM control circuit, an over-current and over-voltage protection circuit, an ADC module, a position detecting circuit, a rotation speed calculation circuit, a logic control circuit, a capture unit, a speed loop, a current loop, a hysteresis comparator and a PI regulator. The control method indirectly controls the current of the doubly salient motor by adopting a dual-loop control type of internal loop for current and external loop for rotation speed and comparing the given rotation speed for reference with the fed practical rotation speed. The method has simple system, firmer structure, reliable operation and high efficiency.

With the fast development of power electronic technologies, the development of power electronic system integration techniques becomes a tendency. In application situations of high-voltage input and large-current output, a DC (direct-current) converter system with multiple modules having series inputs and parallel outputs can be used widely. The key problem of the DC (direct-current) converter system with multiple modules having series inputs and parallel outputs is to ensure voltage sharing of input ends of all modules in the system. For the purpose of realizing the voltage sharing, a voltage loop, a current loop and a voltage-sharing ring are traditionally used to control, each module is required to input voltage detection signals, the circuit is complicated and the control difficulty is high. The invention provides a voltage-sharing technology among modules at input ends, thus realizing the voltage sharing of the multiple modules at the input ends. The control characteristics are as follows: a voltage-current dual-loop control method is adopted, voltage sampling is output voltage sampling, current sampling is the total current sampling of the current output of each module, and each module is controlled by the same duty ratio, thus realizing the voltage sharing at the input ends. The circuit is controlled simply and certain redundancy is provided.

A fault-tolerant control system and method for variable-speed variable-pitch wind turbines with an inverter-fed generator. When generator faults are detected, the generator torque and / or flux is limited to prevent propagation of the faults and possible failure and shutdown of the generator. The control system and method improves on two-loop control methods for variable-speed variable-pitch wind turbines and provides improved power delivery under fault conditions.

The invention provides a middle-high voltage energy conversion system. The input end of each high-voltage isolation type DC / DC converter in a phase circuit is connected with a public DC bus, and eachhigh-voltage isolation type DC / DC converter adopts an opened loop / closed loop control policy so as to adjust the DC input voltage of the own connected cascading module to an instruction value relatedto the voltage of the public DC bus; the system controller at least adopts the voltage-current dual-loop control policy so as to compute three phase modulation instructions sent to various cascading modules of three phases according to the parameter related to the voltage of the public DC bus, and the grid-connected control of three phase circuits is realized; and then each high-voltage isolationtype DC / DC converter can realize the modular control by using the same policy, the current sharing can be realized without using the coupling control in the prior art, and the problems of complex control policy, high cost, and bad system output stability and the reliability caused by the coupling control in the prior art are avoided.

The invention relates to a rapid reflection mirror stabilization control method based on dual-disturbance observers; on the conventional speed and position dual-loop control basis, an accelerometer and a gyro can respectively used to form a disturbance observation circuit, thus directly carrying out disturbance dual-feedforward compensations; the obtained disturbance quantity refers to disturbances on a rapid reflection mirror, and has nothing to do with the disturbance transmission characteristics; an acceleration measurement based disturbance observer feedforward node is given by a speed controller, which means the direct disturbance acceleration feedforward is presently realized; in addition, a speed measurement based disturbance observer feedforward node is given by a position controller, which is equivalent to the speed feedforward. Viewed from the physics meaning angle, the accelerometer realizes the disturbance acceleration feedforward, the gyro realizes the disturbance speed feedforward, and dimension equity is realized, so the disturbance observers can accurately observe the disturbance speed and acceleration for direct compensations; the feedforward controller is simple to design, and easily realized in engineering.

Disclosed is a repetitive dual-closed-loop control method for an LCL type grid-connected inverter. According to the method, the difference value between a given grid-connected current and an actual grid-connected current is used as input of a repetitive controller; the sum of the output of the repetitive controller and the given grid-connected current is used as a given value of an internal loop; the difference value between the given value of an internal loop controller and the actual grid-connected current is used as the input of an internal loop PI controller; the output of a power grid voltage which passes through a feedforward transfer function is used as the output of a power grid voltage feedforward link; and the output of the internal loop PI controller and the output of the feedforward link are added together to be used as a control signal for switching on and switching off an inverter bridge switching tube in an inversion link. According to the repetitive dual-closed-loop control method, the single grid-side current feedback is adopted, so that the dual-loop control is realized, and the cost is lowered; meanwhile, due to the PI controller and the repetitive controller which are connected in series, the decoupling of the controllers is realized; and the grid-connected system has higher steady-state control precision, higher dynamic response speed and higher robustness.

The invention discloses a superheated steam temperature active-disturbance-rejection cascade control method based on multi-objective optimization. The superheated steam temperature active-disturbance-rejection cascade control method adopts double loop control, wherein an inner loop is a PI controller, and an outer loop is a multi-objective optimized active-disturbance-rejection controller; the multi-objective optimized active-disturbance-rejection controller regards a valve opening degree of a superheated steam temperature system as input, and regards an outlet temperature of the superheated steam temperature system as output; a frequency stable region is obtained by adopting a calculation method ensuring system stability, the frequency of an augmented state observer is searched by adopting a multi-objective intelligent optimization algorithm in the frequency stable region, a state of disturbance is observed by means of the augmented state observer, and rapid disturbance elimination isrealized. The superheated steam temperature active-disturbance-rejection cascade control method can precisely adjust the flow rate of the desuperheating water, quickly suppresses the influence of load changes on main steam temperature, improves the power generation efficiency of a boiler, and ensures the service life of metal equipment and the safe operation of a power station.

The present disclosure is directed to a High Voltage Direct Current (HVDC) link with Voltage Source Converters VSC and interconnecting two power systems. A model-predictive control with a receding horizon policy is employed for controlling the outer loop of a two-loop or two-layer control scheme or setup for the HVDC link. The two-loop control scheme takes advantage of the difference in speed of the dynamics of the various system variables of the HVDC link and the interconnected power systems. Model-based prediction representative of the interconnected power systems' behavior enables comparison of the future effect of different control inputs applied within the control scheme, while taking into account any physical, safety and operating constraints. It is valid for a complete operating range, e.g., it avoids performance degradation when moving away from the nominal operating point of the control scheme for a HVDC link.

The invention discloses a networking and off-network uniform control method of an energy storage inverter. According to the method, a control system is adopted; when the inverter is in a networking / off-network state, the control system adopts voltage and current dual-loop control, the outer loop is a voltage outer loop, an inner loop is a current inner loop, the inner and outer loops adopt PI control, the voltage outer loop is in a saturation / desaturation state, so that the inverter works in a current source mode / voltage source model; when in a state between a networking state and an off-network state, the inverter can be seamlessly switched between the two working states. The networking and off-network uniform control method of the energy storage inverter provided by the invention is capable of realizing automatic and smooth switching among the networking state, the off-network state and the state between the networking state and the off-network state.

The invention discloses a trailer control valve which comprises a valve body with an inner cavity. A travel brake cavity, a large piston return cavity, a booster cavity, an air outlet cavity and a parking cavity are formed in the inner cavity of the valve body from top to bottom in sequence, an air inlet, an air supply opening, an air outlet, an exhaust port, a travel control opening and a parking control opening are communicated with the inner cavity of the valve body and are formed in the valve body, a pressure increasing valve, a pressure reducing valve and a pressure preparing valve which are communicated with one another are arranged on the valve body, the air inlet is communicated with an air cylinder of a motor tractor, the air supply opening is communicated with the air inlet through a throttling valve and outputs air pressure to an energy supply pipeline of a trailer, the air outlet is communicated with the air inlet through a combined valve, and the combined valve is a normally-closed valve and is controlled by the travel control opening / the parking control opening. Double-loop control of electric control signals and air control signals is adopted, the electrical control over the trailer control valve is achieved, the defect that in the traditional air pressure control process, due to the fact that the pipeline is long, air pressure signals are slow to transmit is overcome, and the vehicle brake response time is shortened.

The invention provides a public transport priority signal timing optimization method suitable for high saturation intersection. For the high-saturation intersection with public transport priority, after the green time extension strategy is adopted, signal timing is optimized, that is, green time extension is further adopted for each subsequent flow direction, queue length can be restored to zero in three cycles, delay increase of other non-priority vehicles caused by the green time extension strategy is reduced, for the signal timing optimization method, the minimum amount of delay increase istaken as the optimization goal, constraints such as the queue length, the number of cycles required to restore the queue length to zero, the minimum green time and dual-loop control are considered, and a model is established for optimization. The method is advantaged in that public transport signal priority can be provided under the condition of high intersection saturation, signal timing optimization is carried out, so the use scope of public transport signal priority is extended, and the method is conducive to promotion of public transport priority.

The invention belongs to a charging control circuit for a supercapacitor based on a non-adjusting-busbar mode of a spacecraft. The circuit can increase the charging current for the supercapacitor with the rise of the busbar voltage; when a constant voltage point of the supercapacitor is achieved, a constant voltage control state is performed. The charging control circuit comprises a super-buck voltage-reduction power module, an electric current loop-voltage loop dual-loop control module, a charging current reference follow-up busbar voltage control module, and a supercapacitor constant-current constant-voltage control module. According to the charging control circuit, the supercapacitor, serving as a backup power, satisfies the power requirement of the busbar preferably; with the increase of excessive energy, the busbar voltage rises gradually, and the charging current is increased gradually; and the charging control circuit is simple in control structure, less in required devices and simple in interface.

The invention discloses a control method of a trailer control valve. A double-loop control system of the trailer control valve is formed by an electric control loop and an air pressure control loop, the electric control loop and the air pressure control loop carry out concurrent control, the air pressure control loop works under the normal condition, and when the air pressure control loop cannot complete braking, the electric control loop assists the air pressure control loop in working. The double-loop control of electric control signal and air control signals is adopted, signals are collected by a pressure sensor arranged at an air outlet and are fed back to a controller, then the controller controls a pressure increasing valve, a pressure reducing valve and a pressure preparing valve to be opened and closed, electrical control over the trailer control valve is achieved, the defect that in the traditional air pressure control process, due to the fact that the pipeline is long, air pressure signals are slow to transmit is overcome, and the vehicle brake response time is shortened.

The invention provides a remote control parking lot barrier with open-loop control. The remote control parking lot barrier comprises a mounting seat (1), wherein a control device (10), a motor (2), a screw rod (3) and a bottom rod (6) are arranged on the mounting seat (1); a detachable storage battery (8) is arranged on the control device (10); a position reader (r) is arranged on the end face, close to the screw rod (3), of the motor; a position signal producing device (c) corresponding to the position reader (r) is arranged on the screw rod (3); a number of turns of rotation of the screw rod can be obtained by reading the position signal producing device (c) by the position reader (r); a wireless signal receiving module (15) and a vehicle departure sensor module (16) are respectively mounted on the two sides of the upper side of a rotatable panel (5) so as to receive signals.

The invention relates to a control method for improving power grid frequency stability of a flexible DC system converter. The method is implemented according to FLC control and virtual synchronous control of a DC frequency limiter, in FLC control link, active power adjustment increment Delta PFLC required by frequency support of an MMC is obtained by detecting AC power grid frequency changing quantity and additive frequency feedback control loop. The method is characterized in that a frequency reference and a phase reference of an MMC output voltage are obtained by a virtual synchronous control-based active power control loop, a voltage amplitude reference of the MMC output voltage is obtained by a reactive power or AC voltage control loop, and AC voltage closed-loop tracing control is achieved by a voltage-current dual-loop control strategy after the phase reference and the amplitude reference of the output voltage are obtained.

The invention discloses a method for controlling a cascaded multi-cell high-power high-frequency ice melting power supply, which includes the following steps: S1, an input side implements input-side power factor rectification through instantaneous direct current control to suppress the input-side harmonic, wherein the direct current control is composed of current inner loop control and voltage outer loop control; S2, SPWM inversion control is carried out on a combined inverter, and multiple combined phase shifting H-bridge inverter structure control is adopted; and S3, the combined inverter adopts input voltage sharing and output current sharing control. The technical problems in the prior art are solved, for example: there is high harmonic in the ice melting excitation input power supply,and the input current is of low quality; and the output harmonic at the output side is high, and loop current is generated, which reduces the safety of the ice melting power supply.

The invention relates to a dry quenching waste heat recovery steam generator turbine steam admission / emission control method. The method comprises the following steps: a speed sensor acquires a steam turbine spindle speed signal and performs display as a steam turbine speed monitoring value; PID (proportional-integral-derivative) cascade control is carried out on the steam turbine steam admission / emission pressure by using a DCS (distributed control system); a double-loop control system is adopted, wherein the primary loop is steam admission / emission pressure, and the auxiliary loop is steam admission / emission flow rate; the DCS outputs a current control signal, so that the main steam valve and steam emission regulating valve reach the corresponding opening; and the output of an electrohydraulic servo valve is regulated by a displacement sensor so as to control the actual speed of the steam turbine to be consistent with the target speed. On the basis of the conventional turbine control system, the steam turbine steam admission / emission pressure is respectively subjected to PID cascade control by using the DCS, so that the turbine steam admission pressure and steam emission pressure are kept stable, and the disturbance on the steam turbine is reduced when the load is increased or decreased, thereby ensuring the stable operation of the steam turbine.

The invention discloses a control method for inhibiting the offset of a transient virtual power angle curve of a drop-controlled inverter. A feedforward parameter adding method is adopted for calculating an output current of the inverter and carrying out feedforward control on the output current, so that the voltage tracking performance of the inverter is improved, and the transient stabilization of the inverter is kept. Two feedforward output voltage estimated values are added to two current reference values generated by original voltage outer rings of the inverter, so that neo current reference values are obtained. By adopting the method, the transient tracking performance of the voltage is improved, the transient offset of the virtual power angle curve is effectively inhibited, additional sensors are not needed, and the good transient state and the small interference performance of the system are ensured; in addition, the method can be applied to inverters under dual-loop control such as a virtual synchronous machine, the method can also be further popularized to large interference scenes such as multi-machine passive isolated grids and isolated grid large-load switching, and the transient stabilization of the system is improved.

A double-loop control system with a single hydraulic motor relates to a technical field of hydraulic transmission control, including a hydraulic motor (1), a positive control loop (2), a negative control loop (3), a hydraulic pump (4), an accumulator (5), and an oil tank, wherein the hydraulic motor (1) adopts a unique thrust structure with four inlet / outlet ports; the positive control loop (2) and the negative control loop (3) independently control the hydraulic motor (1), wherein the positive control loop (2) and the negative control loop (3) drive together or only one drives; or braking kinetic energy and potential energy of loads are stored in the accumulator (5) for energy recovery. The present invention uses only one hydraulic motor for satisfying different work conditions and different load driving requirements with advantages such as simple structure, high system reliability and high energy efficiency.

The invention relates to a direct current micro-grid oscillation suppression method based on a band-pass filter in a master-slave mode. The direct current bus voltage is controlled by a main power supply, a voltage and current dual-loop control mode is adopted, the method aims at two kinds of oscillation modes possibly occurring in a direct current micro-grid, a control system of the main power supply is improved, a feedback channel using output voltage and output current as the feedback quantity is newly added, two groups of corresponding oscillation suppression links are formed, and in a high-frequency component oscillation suppression link, the output voltage of a feedback quantity direct current bus is used as the compensation quantity to be added to the reference voltage of the main power supply control system after passing through a high-frequency band-pass filter; in a low-frequency component oscillation suppression link, the output current of the feedback quantity main power supply is used as the compensation quantity to be added onto the reference voltage of the main power supply control system after passing through a low-frequency band-pass filter. The direct current micro-grid oscillation suppression method has the advantages that the stable operation of the system can be ensured, the realization is simple, and the reliability is higher.

The invention relates to a main brake valve with electronic control and pneumatic control, which is characterized in that dual-circuit electronic control and dual-circuit pneumatic control are generated respectively by electrical signals and pneumatic signals which are obtained through detecting a brake intent, thereby controlling the rise and drop of brake pressure of a brake system, wherein twocontrol circuits independently exist in the main brake valve, when one of the control circuits malfunctions, the other control circuit keeps running; and when one circuit in the dual-circuit control malfunctions, the other circuit still takes effect. By using the main brake valve provided by the invention, braking operations implemented by drivers become safer and more reliable.