50 results about "Multi loop control" patented technology

The invention discloses a microgrid inverter multi-loop control method based on a virtual synchronous generator, and the method comprises power control of an outer loop and voltage current control of an inner loop. The power control of the outer loop comprises the following steps: measuring the three-phase voltage and current of an output side of an inverter, calculating active power and reactive power according to the instantaneous power theory, carrying out calculation and regulation through an active power-frequency equation, a reactive frequency equation, a torque inertia equation and an electromagnetic transient equation of a synchronous motor, obtaining the amplitude of an output voltage and a phase angle given value, and then carrying out modulation through voltage and current double loops. The method can achieve the non-corresponding control of voltage size and frequency well, outputs active and reactive power, can achieve precise manual control, and has the characteristics of V/F and PQ control. When a fault happens to a power grid, the method can simulate the primary modulation, primary voltage regulation and inertia characteristics of the synchronous generator, participates in the power grid adjustment, provides frequency and voltage support, and facilitates the stabilization of the power grid.

The invention belongs to the field of servocontrol, realizes a high-performance tri-redundancy steering engine based on a single-channel dual-processor structure, and relates to an embedded type control module taking a high-speed digital processor (DSP) as a core and a redundant configuration and a management proposal thereof. The single-channel hardware of the steering engine mainly comprises a forestage processor (FCP) 09, a secondary processor (SCP) 10, a fault isolation module 21, an LVDT displacement sensor 18, a current sensor 24, an actuating cylinder 20, a data cross transmission channel (CCDL) 23, and the like. Compared with the prior steering loop mode comprising a flight control computer and an actuator, the high-performance tri-redundancy steering engine reduces the workload of a flight control computer and completes control plane closed-loop control and redundancy management task inside the redundancy steering engine, thereby eliminating performance coupling between the flight control computer and the steering engine. Moreover, by adopting strategies such as multi-loop control, dual-processor mutual monitoring and data cross transmission, the steering engine effectively improves control performance and reliability.

The invention provides a multi-loop control method for a magnetic resonance coupling wireless power transmission system. According to the method, three loops are used for controlling the resonance current on the transmitting side, the output voltage on the receiving side and equivalent load resistance respectively, the three loops are matched, and therefore safety, stability and high efficiency of the system are guaranteed. By the adoption of the method, the main control requirements of the magnetic resonance coupling wireless power transmission system are met, the method is effective and easy to use, and multiple purposes are achieved.

The invention relates to a fluctuation source localization method of multi-loop oscillation of a novel process industry. According to the method, a frequency domain independent component analysis (ICA) is employed to carry out independent component decomposition on industry historical process data; a variable quantity that plays a leading role in fluctuation oscillation and a dominant frequency can be screened; a local directed coherence analysis is carried out on the screened data; and a cause-and-effect relationship graph is used to visually express a cause-and-effect relationship between loop variables, so that a propagation path of a fluctuation interference can be characterized; process priori knowledge is used to simplify the cause-and-effect relationship graph as well as a threshold automatic searching mode is utilized to filter a secondary cause-and-effect relationship branch, so that a main propagation path of fluctuation is obtained and thus a fluctuation source is localized and identified. Compared with the prior art, the technology employed in the invention enables the method to have the following beneficial effects: a signal analysis on a frequency domain is utilized to reveal an essential attribute of oscillation of a multi-loop control system, so that a fluctuation source of the oscillation is determined; and thus, it is beneficial for a factory engineer to carry out follow-up maintenance and repairing work of a fault circuit.

The invention relates to a six-axis cooperated robot multi-loop control system and a control method thereof. The system comprises a synchronous inductor, a distance sensor, a machine vision device and a robot control unit, wherein the robot control system is used for controlling the movement and the processing of a robot, and comprises a multi-axis servo control module, an image collecting module, a power supply board, an in-arm motor driver, a motor and man-machine interaction equipment, wherein the multi-axis servo control module, the image collecting module and the power supply board are integrated. According to the method, the machine vision is used; the distance sensor and the synchronous inductor are combined; the precise position of a workpiece on the flow line can be obtained; the on-line processing is performed. The control system provided by the invention has the advantages that the structural design is simple and reasonable; the operation and the use are convenient; the relying of the robot on a high-precision motor and a speed reducing machine is reduced; the cost is obviously reduced. The control method has the advantages that the flow process is simple; the problems of high mechanical manufacturing cost, fatigue abrasion and matching difficulty with the flow line in the prior art can be solved.

The invention provides a method for the performance evaluation and the failure diagnosis of a coke oven multi-loop control system; the method for the performance evaluation of the coke oven multi-loop control system adopts a fuzzy comprehensive evaluation method to calculate performance level of a coke oven heating combustion control system; the fuzzy comprehensive evaluation method includes two evaluation factors: improved difference coefficient and process capability index; the method for the failure diagnosis comprises the steps: firstly establishing a failure knowledge base based on the improved difference coefficient and the process capability index of multi-loop control, searching for all the possible failure resources according to the optimal matching principal by regarding the improved difference coefficient and the process capability index as index in case that the performance level of the coke oven heating combustion control system is qualified or below, and embodying these failure sources visually in the form of text. The method enhances automation degree of failure elimination, dramatically lowers labor intensity of staff and raises working efficiency.

Provided is a digital DC/DC power module with multi-mode multi-loop control. The digital DC/DC power module with multi-mode multi-loop control is adaptive to complexity, high performance, and high reliability of the application of a current DC/DC power module and is high in integration degree and high in flexibility, and comprises implement contents including structural composition, components and parts, heat dissipation and packaging, a work principle, an automatic voltage-increasing and decreasing topological structure, feedback control, increment PID control, input voltage automatic tracking, multi-loop cooperative control, data communication, a power conversion circuit, and a core control circuit.

The invention provides a multi-loop control parameter identification method and system for a grid-connected inverter. The multi-loop control parameter identification method comprises the following steps of acquiring a circuit element parameter group W; determining a plurality of groups of steady-state operation point parameter groups O and impedance value sequences under a plurality of groups of steady-state operation points based on the conventional operation condition range of the grid-connected inverter; and performing control parameter fitting on the parameter group, the impedance numerical value sequence and the circuit element parameter group under each group of steady-state operation points based on an impedance/admittance model of the inverter to obtain control group parameters; fitting precision of different loop control parameters is improved by adopting a frequency band-by-frequency band fitting mode, influences of different steady-state operation points on impedance characteristics of the inverter and influences of phase-locked control and direct-current bus voltage control frequency band superposition are considered, and applicability of parameter fitting is improved;a problem of accurate modeling caused by black/gray box control of an actual grid-connected inverter is solved; and the obtained amplitude-frequency curve and phase-frequency curve of the broadband impedance of the steady-state operation point meet the analysis requirements on the characteristic mechanism of the device.

The invention discloses a multiloop control circuit and a control method thereof. The multiloop control circuit comprises a control unit, at least two main lines, at least two first control switches and at least two second control switches, wherein the control unit is supplied with the power source by a power source input unit and is used for outputting a control signal. The first end of each main line is connected with a power source end by the first control switch and is grounded by the second control switch, and two LEDs having opposite polarity are connected between second ends of random two main lines in parallel; control ends of the first control switch and the second switch are respectively connected with an output end of the control unit, the first control switch and the second controls witch receive the control signal output by the control unit and are at a conducting state or a closing state according to the control signal. The invention can realize N*(N-1) loop by N main lines so as to reduce the using amount of the main lines, greatly simplify the circuit structure and also reducing the cost of products.

Improved adjustment of transmission power in a communication system is provided. In one embodiment, in a point to multipoint communication system, transmission power of a subscriber unit is controlled based on power measurements made at a central access point. Power measurement information based on transmissions occurring at irregular intervals may be combined in a beneficial manner to control transmission output power. In one embodiment, a power regulation process determines a series of difference values indicating the differences between desired received power level at the central access point and measured received power level. A smoothing process is applied to the difference values. One or more parameters of the smoothing process vary with elapsed time since a last available power measurement.

The invention uses an input signal directly from a fuel flow device to control the amount of ammonia injected into a flue gas stream for NOx reduction for boilers. The control system receives a signal directly from a fuel flow device that indicates the amount of fuel flow and corresponding NOx emissions. The signal is processed using an algorithm with a multi-loop controller and an ammonia mass flow control valve with temperature and pressure corrections to determine how much ammonia must be injected into the flue gas in the presence of a catalyst to achieve the desired NOx emissions reductions. A dilution air blower transports ammonia to an injection grid and subsequently, the ammonia reacts with the flue gas in the presence of a catalyst to reduce the amount of NOx emissions to the desired level.

A bias function that allows a boiler operator to manually increase or decrease the flow of ammonia in order to vary the amount of NOx reduction is included and can be used as an alternate to automatic operation, thus allowing an operator to dictate the amount of ammonia to be injected into the system. Air temperature and pressure correction functions are also included to adjust the ammonia flow based on a given temperature and fuel flow.

A valve with double stages of seal device is composed of valve body, connection unit, spring and flow guide unit. It is featured as setting the first seal device at inlet section of valve body and the second seal device at outlet section of valve body, connecting valve clack of the first seal device to valve clack of the second seal device by connection unit. The said valve can not only be used on pressure control, flow rate control and flow direction control but also can be used on water level control, temperature control, multiloop control, electromagnetic ¿C automatic control, etc.

A method for judging margin of a multi-loop control system comprises the following steps: step 1, equivalently transforming the multi-loop control system into a non-unit feedback type single-loop control system; step 2, calculating a transformed open-loop transfer function open (s); step 3, calculating cut-off frequency as phase margin according to the open-loop transfer function open (s); step 4,calculating delay margin Dm, and judging control margin of the multi-loop control system according to the delay margin Dm. The method obtains delay margin of the control system through calculation, as compared with phase margin and amplitude margin, the delay margin can better explain control quality and robustness of the multi-loop control system, and the method has universality for the multi-loop control system.

The invention discloses a structure for reducing flashover length of a moulded case circuit breaker. The structure comprises a big cover and is characterized in that a flashover guiding wall and flashover blocking walls are arranged on the big cover, wherein the front face of the flashover guiding wall faces towards the direction of an electrode generating electric arcs; and the two flashover blocking walls are located in front of the two ends of the flashover guiding wall. The structure of the flashover guiding wall and the structure of the flashover blocking walls change the heading direction of the electric arcs a plurality of times so as to lengthen the moving distance of the electric arcs, meanwhile, the electric arcs collides multiple times so that the electric arcs are weakened to certain extent, and thus, the flashover distance of the circuit breaker is greatly reduced, and the safety performance of the circuit breaker is increased. The structure disclosed by the invention has the characteristics of simple and reliable structure and low cost, and is particularly suitable to being mounted in a small-space and multi-loop control devices.

The invention relates to a parallel microgrid multi-phase three-phase inverter parallel system and a distributed control method thereof. The system comprises a plurality of three-phase inverter parallel units, a three-phase load and an AC bus, wherein each three-phase inverter parallel unit comprises a three-phase inverter circuit, a control circuit of the three-phase inverter circuit and equivalent transmission line impedance. The coordinated control of the multi-parallel inverters without a communication line or under very few communication lines can be achieved effectively, and good voltageregulation and current sharing characteristics can be achieved. The system is fast in dynamic response, does not require a multi-loop controller and is simple and effective. The system can serve as anetworking component in an isolated microgrid to provide voltage and frequency support for the system. In case of power fluctuation or load sudden change of the system, rapid accurate power distribution can be achieved, and the power supply reliability of the isolated microgrid is ensured.

The invention provides a multi-loop intelligent energy-saving control system and method. The multi-loop intelligent energy-saving control system comprises a cloud server which is configured to customize or load a loop control strategy as required according to the feedback relay state of an edge gateway and issue the loop control strategy to the edge gateway; an edge gateway which is configured todecompose the loop control strategy and issue a relay control command to the corresponding loop controller according to different loops where the loop controllers are located; at least two loop controllers, wherein each loop controller is configured to analyze the corresponding relay control command, control the corresponding relay to act, and feed back the relay state to the edge gateway after the action of the relay is completed. The system achieves the remote intelligent control of the on and off of the multi-loop electric equipment, and achieves the intelligent energy saving on the basis of the multi-loop control.

The invention relates to a distribution box. The distribution box comprises a box body and a box door, and the box body is hinged with the box door; and the box body comprises a multi-loop control terminal, a main branch circuit breaker, a standby branch circuit breaker, a main branch current transformer, a standby branch current transformer, a main branch contactor, a standby branch contactor anda power supply module; the incoming line of the box body is divided into at least two branch circuits, namely a main branch circuit and a standby branch circuit, so that the reliability of the distribution box is improved. According to the invention, local and remote protection, control, monitoring and management of all parts of the distribution box can be realized, intelligent control and faultalarm can be carried out on the power distribution system, and a manual operation display unit is added, so that the safety of the distribution box is improved, the power distribution box is convenient to maintain, all parts of the power distribution box are high in structural modularization degree, the distribution box is good in safety, high in reliability, high in integration degree and intelligent degree and convenient to assemble, maintain, monitor and control, better controllability and expandability are achieved, and the increasingly high power distribution and power control requirements of users can be met.

The invention provides a new energy power generation oscillation suppression method and system, and the method comprises the steps: collecting the voltage and current instantaneous quantity of a unit port in real time, obtaining the oscillation components of different frequency bands such as sub/super synchronization, middle frequency band, high frequency band and the like through online FFT analysis, triggering an alarm signal through oscillation recognition and judgment, starting the online adjustment of control parameters, and achieving the suppression of new energy power generation oscillation. And multi-loop control parameters of a phase-locked loop, a current loop, a direct-current voltage loop and the like of the wind turbine generator are adjusted. According to the method, a control parameter online adjustment method for the oscillation frequency of each frequency band is considered, and adjustment and optimization of the control parameters and effective suppression of the broadband oscillation problem of the wind turbine generator in a weak power grid are realized in real time. Meanwhile, the method is suitable for different types of new energy power generation devices, has universality, and is beneficial to solving the problem of grid-connected oscillation of various types of actual new energy power generation devices.

The invention discloses a resistive inverter robust droop multi-loop control method, which comprises four parts including application of a multi-inverter parallel system, robust droop multi-loop control, voltage-current double-closed-loop control and SPWM modulation. A power outer loop adopts a robust droop controller, and can reduce the influence of an equivalent output impedance difference on precise distribution of power. The equivalent output impedance of inverters is resistive through introducing virtual complex impedance, the influence of the impedance difference can be reduced, the harmonic circulating current can be suppressed, and harmonic current sharing is realized. By adopting quasi-resonance PR control, zero steady-state error control of output voltages of the inverters in a wider frequency band can be realized, the output voltage deviation between the inverters is reduced, and the circulating current can be suppressed. The resistive inverter robust droop multi-loop control method adopts the voltage-feedforward capacitive current proportional control to improve the transient response and current anti-disturbance capability of the system.