Showing papers on "Dynamic braking published in 2020"

Fault Ride Through Capability Improvement of DFIG Based Wind Farm Using Nonlinear Controller Based Bridge-Type Flux Coupling Non-Superconducting Fault Current Limiter

Abstract: High penetration of Doubly Fed Induction Generator (DFIG) into existing power grid can attribute complex issues as they are very sensitive to the grid faults. In addition, Fault Ride Through (FRT) is one of the main requirements of the grid code for integrating Wind Farms (WFs) into the power grid. In this work, to enhance the FRT capability of the DFIG based WFs, a Bridge-Type Flux Coupling Non-Superconducting Fault Current Limiter (BFC-NSFCL) is proposed. The effectiveness of the proposed BFC-NSFCL is evaluated through performance comparison with that of the Bridge-Type Fault Current Limiter (BFCL) and Series Dynamic Braking Resistor (SDBR). Moreover, a dynamic nonlinear controller is also proposed for controlling the operation of the BFC-NSFCL. Extensive simulations are carried out in the MATLAB/SIMULINK environment for both symmetrical and unsymmetrical temporary as well as permanent faults. Based on the simulation results and different numerical analysis, it is found that the proposed nonlinear controller based BFC-NSFCL is very effective in enhancing the FRT capability of the WF. Also, the BFC-NSFCL outperforms the conventional BFCL and SDBR by maintaining a near-seamless performance during various grid fault situations.

Energy Regenerative Damping in Variable Impedance Actuators for Long-Term Robotic Deployment

Abstract: Energy efficiency is a crucial issue towards long-term deployment of compliant robots in the real world. In the context of variable impedance actuators (VIAs), one of the main focuses has been on improving energy efficiency through reduction of energy consumption. However, the harvesting of dissipated energy in such systems remains under-explored. This study proposes a variable damping module design enabling energy regeneration in VIAs by exploiting the regenerative braking effect of dc motors. The proposed damping module uses four switches to combine regenerative and dynamic braking, in a hybrid approach that enables energy regeneration without a reduction in the range of damping achievable. A physical implementation on a simple VIA mechanism is presented in which the regenerative properties of the proposed module are characterized and compared against theoretical predictions. To investigate the role of variable regenerative damping in terms of energy efficiency of long-term operation, experiments are reported in which the VIA, equipped with the proposed damping module, performs sequential reaching to a series of stochastic targets. The results indicate that the combination of variable stiffness and variable regenerative damping results in a $\text{25}\%$ performance improvement on metrics incorporating reaching accuracy, settling time, energy consumption and regeneration over comparable schemes, where either stiffness or damping are fixed.

Motor dynamic braking circuit and motor dynamic braking method

Abstract: The invention discloses a motor dynamic braking circuit and a motor dynamic braking method After being rectified by a rectifier bridge module, alternating current is converted into direct current busP/N with stable voltage through bus capacitor filtering, and then the direct current is converted into the alternating current through an inverter bridge module to drive the motor; one end of a power-on soft start module is connected to the bus positive P, the other end is connected with one ends of a bus capacitor module and a regenerative braking module, the other ends of the bus capacitor module and the regenerative braking module are connected to the bus negative N, and a dynamic braking module is directly connected to the direct current bus P/N The dynamic braking circuit completely multiplexes the body diodes of the inverter bridge module to achieve rectification, three additional diodes do not need to be additionally arranged on each axis, the system cost is reduced, and the PCB area is reduced; the dynamic braking module shared by the multi-axis common bus system can be supported without adding any additional wiring, so that the system wiring is simplified, and the cost of wiring terminals and cables is reduced

Braking Dynamic Performance

Abstract: The study of braking on straight road is performed using mathematical models similar to those seen in Chap. 23 for longitudinal dynamics. But in this case, the presence of suspensions and the compliance of tires are neglected and the motion is described by the longitudinal equilibrium equation (23.1) alone.

Stabilization of Inter-Area Oscillations in a Two-Area Test System via Interval Type-2 Fuzzy Based Dynamic Brake Control

Abstract: Inter-area oscillations are, by far, the most detrimental to the synchronous integrity of interconnected power systems. This detriment comes from their wide frequency spectrum and the large numbers of the participant generators. The inherent poor damping associated with the inter-area oscillations leaves open wide probabilities for irrevocable widespread blackouts with the consequent eventual devastating outcomes measured in terms of the huge economic casualties and the possible human fatalities. This article explores the influences of the Interval Type-2 fuzzy logic-based strategized dynamic braking interventions of dual brake models, namely Thyristor Controlled Braking Resistors (TCBRs), for neutralizing the jeopardy of negatively damped inter-area power oscillations in Kundur’s two-area test system, using MATLAB™/Simulink environment. The relative inner generator's speed deviation is employed in this work as a control signal to the proposed controller. The effectiveness of the proposed scheme is authenticated by considering four case studies with different severity degrees. By analyzing the performance repercussions due to four disturbances, without the implementation of the proposed scheme, the unstable nature of the system responses is clearly noticed. With the implementation of the proposed scheme, the system oscillatory behavior is stabilized in an appropriate manner. The performed comparative non-linear time-domain simulation results emphasize the great potential of the proposed scheme in mitigation of inter-area power oscillations according to the considered disturbances. The proposed scheme is simple yet effective in treating the inter-area oscillations appropriately under the considered case studies.

Energy needs in dynamic braking on Dahlander motor

Abstract: Dahlander motors are using with different speed regulation needs. In this article, dynamic braking is using by injecting a DC voltage to see energy usage at fast and slow rotation. Control of the fast and slow rotation at the control panel using Arduino. The DC voltage variations given are 15 volts, 20 volts, and 24 volts. At a 15 volt DC voltage injection, the energy needed at fast rotation is 0.0018 Wh and at slow rotation 0.00072 Wh. For injection of a 20 volt DC voltage, the energy required for fast rotation at 0.0025 Wh and at 0.00085 Wh for slow rotation. Whereas 24 volt DC voltage injection, the energy needed at 0.0036 Wh for fast rotation and 0.00077 Wh for slow rotation.

Motor drive apparatus and control method thereof

Abstract: In order to achieve a solution to a technical problem to be solved by the present invention, a motor drive apparatus according to the present invention comprises: a DC-side capacitor charged with direct current power; an inverter unit comprising multiple top switches and bottom switches, performing a switching operation so as to convert power stored in the DC-side capacitor into alternating current power, and outputting the converted alternating current power to a motor; a shunt resistor for detecting a current flowing through the DC-side capacitor; and a control unit for controlling the inverter unit to perform dynamic braking for stopping the motor, wherein, before the dynamic braking is performed, the control unit controls the inverter unit to gradually increase a phase current flowing through the bottom switch.

Servo motor dynamic braking circuit and control method thereof

Abstract: The invention provides a servo motor dynamic braking circuit and a control method thereof. The servo motor dynamic braking circuit comprises: an inverter circuit, wherein the input end of the invertercircuit is connected with a bus, and the three-phase output end is respectively connected with the three-phase terminals of a servo motor; a half-wave rectification circuit connected between the inverter circuit and a braking switching circuit and comprising three diodes, wherein the anodes of the three diodes are respectively connected to the three-phase output end of the inverter circuit, and the cathodes of the three diodes are connected with the braking switching circuit at the same time; and the brake switching circuit, wherein one end of the brake switching circuit is connected with thecathodes of the three diodes, the other end of the braking switching circuit is connected with the negative electrode of the bus, the braking switching circuit comprises a plurality of energy-consuming resistors and a control switch, the control switch is connected between the plurality of energy-consuming resistors and the half-wave rectification circuit and used for switching the energy-consuming resistors connected to the circuit. According to the invention, the reliability of the braking circuit is improved, the normal braking of the servo motor is ensured, and the safety is improved.

Multi-brake-device comprehensive control method for preventing flying of belt

Abstract: The invention discloses a multi-brake-device comprehensive control method for preventing flying of a belt. The multi-brake-device comprehensive control method comprises the following steps of: acquiring a speed signal of a belt speed measuring device and/or a load torque signal of a belt frequency converter; comparing the numerical value of the speed signal and/or the numerical value of the load torque signal with a preset value; when the numerical value of the speed signal and/or the numerical value of the load torque signal are/is lower than a normal preset value and higher than a lower limit value, implementing dynamic braking of the frequency converter and controlling a front end feeder to output a frequency upper limit; when the numerical value of the speed signal and/or the numericalvalue of the load torque signal are/is higher than the normal preset value and lower than an upper limit value, starting hydraulic braking in order to reduce speed and controlling the front end feeder to output the frequency upper limit; when the numerical value of the speed signal and/or the numerical value of the load torque signal are/is beyond the upper limit value and the lower limit value,controlling a belt positioned at the front end and a vibratory feeder to stop running, simultaneously starting disc braking to reduce speed, decelerating and stopping the frequency converter; and finally carrying out mechanical band-type brake locking to realize parking. The multi-brake-device comprehensive control method disclosed by the invention has the characteristics of reliable performances,simple control, good braking effect and high automation degree.

Motor drive device

Abstract: A long-life motor driving device is realized. A motor driving device (11) includes: a motor driving circuit (3) configured to supply an alternating electric current to a motor (2); and a dynamic braking circuit (4). The dynamic braking circuit includes: a mechanical switch (SW2) configured to cause a short circuit between windings corresponding to respective two phases; a semiconductor switch (SW1) connected to the mechanical switch in parallel and configured to cause a short circuit between the windings corresponding to the respective two phases; and a first impedance circuit (Z1) connected to the semiconductor switch in series.

Earthing switch having dynamic braking resistors

Abstract: An earthing switch circuit (100) is provided and is connected to a direct current (DC) link (50). The DC link (50) includes a positive terminal (130a) and a negative terminal (13b) and has capacitance or energy storage capability. The earthing switch circuit (100) includes a dynamic braking (DB) circuit (120) having a single or plurality of DB switches (122), at least one DB resistor (124) disposed between the plurality of DB switches (122), and an earthing switch (110) connected between the DB circuit (120) and ground. The at least one DB resistor (122) dissipates energy thermally when performing a dynamic braking operation and simultaneously decreases in-rush current for the earthing switch circuit (100) upon closure of the earthing switch (110).

Torsional Oscillations Mitigation via Interval Type-2 Fuzzy Logic Brake Control

Abstract: Turbine-generator shaft torsional oscillations is an interdisciplinary power system dynamic problem because it encompasses mechanical and electrical sectors of power grids. They give rise to a premature expenditure of fatigue life of the turbine-generator shaft metal which could lead to shaft cracks. This paper introduces an interval type-2 fuzzy logic controller to regularize the dynamic braking interventions of a novel braking resistor model for mitigation of torsional oscillations resulting from unsuccessful autoreclosure procedures near generation stations. The effectiveness of proposed scheme is elucidated by considering the unsuccessful autoreclosure of three-phase-to-ground fault in a single machine infinite bus power system via MATLAB/Simulink-based modeling and simulation environment with the help of interval type-2 fuzzy logic controller toolbox. The comparative simulation results with and without the suggested mitigation regime show that the proposed scheme is effective in the mitigation of torsional torque oscillations

Control system and control method for dynamic braking of motor

Abstract: The invention discloses a control system for dynamic braking of a motor. The control system can achieve better braking efficiency without cooperation of dynamic braking related hardware. The control system comprises a motor; a full-bridge inverter which is connected with the motor and provided with a first circuit and a second circuit, wherein the first circuit and the second circuit are independently provided with a plurality of groups of switching elements; and a driver which is coupled with the full-bridge inverter and the motor and is used for outputting a switching instruction for carrying out pulse width modulation control on the switching elements to the full-bridge inverter and receiving current feedback of the motor. In this way, extra hardware cooperation is not needed, the problem of subsequent maintenance can be reduced under the condition that cost and part losses are not increased, and better braking efficiency is achieved.

Engine with permanent magnets and direct starting from mains and method of its connection

Abstract: FIELD: electrical equipment.SUBSTANCE: invention relates to a motor with permanent magnets and direct starting from a mains intended for driving a centrifugal pump from a three-phase network, as well as a method for its activation, preferably for engines with power of at least 5 kW. Motor with permanent magnets and direct starting from the mains comprises rotor and stator with stator winding, wherein stator winding is made as pole-switched winding. With such method of connection, it is possible to avoid the saddle of the dynamic braking curve slowing the engine acceleration. Polus-switchable winding comprises the first winding stage and the second winding stage, which can operate separately from each other, note also that first stage of winding has number of pole pairs, denoted below as number p1of pole pairs for start, which is not equal to number of pole pairs of second stage of winding, hereinafter referred to as number p2of working pairs of poles.EFFECT: technical result consists in prevention of dynamic braking moment developed during asynchronous acceleration process, by switching pole-switchable winding inducing rotary magnetic field at acceleration stage.12 cl, 9 dwg

Prevent overspeed wind power generator

Abstract: A purpose of the present invention is to provide a wind power generator for preventing overspeed damage, capable of predicting an overvoltage by measuring the inclination of a voltage delivered from a wind power generation part, and preventing electric damage to a wind power control part by consuming energy through a resistor in accordance with an inclination value. To achieve the purpose, the wind power generator for preventing overspeed damage includes: a power generation part generating power through a blade; a power conversion part including a rectification part converting an alternating current of the power generation part into a direct current, a converter part delivering the direct current to a load or a battery, a DC link capacitor formed between the rectification part and the converter part, and a dynamic braking circuit part formed between the rectification part and the DC link capacitor, and selectively operated while consuming the direct current; and a control part measuring the voltage of the DC link capacitor, and controlling the dynamic braking circuit part to make the voltage of the DC link capacitor maintained at no more than a predesignated value.

Elevator door control device

Abstract: Provided is an elevator door control device whereby a door of an elevator can be safely closed during a power failure, and it is possible to prevent placing an excess burden on rescue workers. An elevator door control device pertaining to the present invention is provided with a door dynamic braking control circuit (15) for performing dynamic braking control of a door motor (2) until door closing is detected after the occurrence of a power failure in a state in which the elevator door is in an intermediate position, and discontinuing dynamic braking control when door closing is detected.

Method for controlled motor speed reduction and mechanism for controlling motor speed reduction

Abstract: A self-powered motor braking mechanism (24) includes a dedicated power source (26) sized for braking the respective motor (14) and a dedicated braking circuitry (50) configured to provide hybrid braking of the motor to a targeted stop. The motor braking circuitry is configured, in the event of a loss of primary power driving the motor, to provide a combination of two or more of dynamic braking, active braking and active position control to achieve zero speed of the motor by a target stopping time.

Resistors for dynamic braking

Abstract: A resistor of a powered system includes an elongated body that extends from a first terminal end to an opposite second terminal end. The body forms a continuous path that extends from the first terminal end to the second terminal end and that forms a disc. The body is configured to receive electric current from the powered system at the first terminal end and conduct and provide electric resistance to the electric current received from the powered system to dissipate at least part of the electric current as heat from the body. The second terminal end of the body is configured to be coupled with at least one other resistor of the powered system in one or more of a parallel or series arrangement in an electric circuit.