10 results about "Braking chopper" patented technology

A DFIG wind power facility configured to be operated during grid faults is provided. The wind power facility includes a Doubly-Fed Induction Generator, a control system, an electric converter, a short-circuit controlled switch to selectively short-circuit the stator and a Stator Neutral Brake Chopper coupled to the stator. The DFIG includes a rotor and a stator, the stator including at least one three-phase winding. The electric converter includes a Machine Side Converter, a Grid Side Converter and a DC link connected therebetween. The SNBC includes a three-phase rectifier including three inputs, an impedance and an active high-frequency switch configured to vary the average value of the impedance by adjusting its duty cycle; each of the three inputs of the rectifier is connected to a phase of the at least one three-phase winding of the stator. Methods for operating a DFIG wind power facility during grid faults are also provided.

The present disclosure relates to systems, methods, controllers and computer program products for thermal management of a brake chopper resistor. The system comprises a resistor housing portion configured to receive a cooling fluid in a cooling fluid flow path; a brake chopper resistor in the resistor housing portion; a plurality of temperature sensors in thermal communication with different respective parts of the resistor cooling flow path through the resistor housing portion and configured to measure a first temperature at a first location in the cooling fluid flow path of the brake chopper resistor and to measure a second temperature at a second location in the cooling fluid flow path of the brake chopper resistor; and control logic, configured to compare the first temperature and / or the second temperature to a threshold value or to compare the first temperature with the second temperature, and to make a determination of whether to allow activation of the brake chopper resistor in response to the comparison with the threshold value.

The application relates to the technical field of energy management, and provides an energy storage voltage stabilizer for a high-power multi-motor servo system and a control method thereof, which comprises a main motor driver, an energy storage motor driver, a braking chopper and braking resistor unit, a controller and a rectifier, a soft start circuit and a common DC bus connected in sequence; a bidirectional voltage-lifting converter is arranged on the common DC bus, the high-voltage side of the bidirectional voltage-lifting converter is connected in parallel with the positive bus end and the negative bus end of the common DC bus, and the low-voltage side of the bidirectional voltage-lifting converter is connected with an energy storage unit; the input ends of the main motor driver and the energy storage motor driver are connected in parallel with the positive bus end and the negative bus end of the common DC bus; the braking chopper and the braking resistor unit are connected across the positive bus end and the negative bus end of the common DC bus; the controller is used for controlling the charging and discharging power of the bidirectional voltage-lifting converter and controlling the conduction of the braking chopper and the braking resistor unit. Energy waste is avoided.

In a method for operating a drive system and a drive system for carrying out a method, the electric motor is connected to the AC-side connection of an inverter, the DC-side connection of the inverter is connected to the DC-side connection of the rectifier via an inductance, a capacitance is connected to the DC-side connection of the inverter, a series circuit formed from a resistor and a braking chopper is connected to the DC-side connection of the inverter, and the braking chopper is operated with a pulse width modulation frequency, which is determined by a pseudo-random number generator.

The invention provides a distributed permanent magnet direct drive-based multi-motor efficient cooperative traction controller and a control method. The multi-motor efficient cooperative traction controller comprises a main circuit, a control circuit and a multi-motor efficient cooperative control algorithm module, the main circuit comprises extensible traction, brake chopping, excitation and DC-DC modules, and the control circuit is provided with a multi-protocol gateway board, a traction / excitation main control board, a fault recording board and a back board; and the traction main control board operates wheel diameter difference dynamic identification, torque cooperative distribution and line-vehicle coupling optimization algorithms to eliminate idling / sliding caused by the wheel diameter difference in real time and adaptively correct traction force under a complex line. Through wheel diameter difference dynamic identification and a line vehicle coupling optimization algorithm, on an integrated hardware platform integrating traction, excitation and braking functions, millisecond-level cooperative torque distribution is carried out on the distributed permanent magnet direct drive multiple motors, so that wheel idling sliding and invalid traction are eliminated, and efficient and energy-saving operation under all working conditions is achieved.

A circuit includes a first power switch, a second power switch, a third power switch, and a fourth power switch in series to form a first branch in parallel with a second branch, the second branch including a first capacitor and a second capacitor in series with a first node between the first capacitor and the second capacitor. A first brake resistor is connected in series with the first chopper switch to form a third branch, and a second brake resistor is connected in parallel with the second chopper switch to form a fourth branch. The third branch is located between the terminal of the first capacitor and a second node, which is located between the first power switch and the second power switch. A third node is arranged between the second power switch and the third power switch. The fourth branch is located between the terminal of the second capacitor and a fourth node, which is located between the third power switch and the fourth power switch. The third capacitor and / or inductor forms a fifth branch between (i) the second node and the fourth node or (ii) the first node and the third node.

The invention relates to a method for the intelligent heating of a fuel cell system (1), wherein a heat required for heating a fuel cell system (1) integrated in a vehicle (2) to an operating temperature is provided by a secondary brake system (3) of the vehicle (2) in the form of at least one retarder (3.1) and / or a brake chopper (3.2), The invention is characterized in that a planned journey is carried out with the vehicle (2), wherein the vehicle (2) switches from battery-electric operation to a fuel cell operating mode at a switchover time during the journey, in which a drive energy required to drive the vehicle (2) is provided by the fuel cell system (1), wherein an analysis of the planned journey is carried out before the start of the journey in order to determine an amount of heat which can be drawn from the secondary braking system (3) during a period of the journey, and wherein the switchover time is determined as a function of the amount of heat which can be drawn and / or heating of the fuel cell system (1) is started before the start of the journey in order to ensure that the fuel cell system (1) has reached the operating temperature when the switchover time is reached.

A drive device for a railway vehicle operates by receiving power supply from an alternating-current overhead contact line or a three-phase generator. The drive device for a railway vehicle is configured such that a voltage output from a main transformer is applied to alternating-current input ends in a converter circuit via a first switch. A first phase voltage among voltages output from the three-phase generator is applied to an alternating-current input end in a first leg of a brake chopper circuit via a second switch. Second and third phase voltages among the voltages output from the three-phase generator are applied to the alternating-current input ends, respectively, via the second switch.

The invention relates to a three-level brake chopper comprising a first controllable semiconductor switch (T1) connected between a positive direct current pole (dc+) and a first connection point, a second controllable semiconductor switch (T2) connected between the first connection point and a neutral direct current pole (NP), a third controllable semiconductor switch (T3) connected between the neutral direct current pole (NP) and a second connection point, a fourth controllable semiconductor switch (T4) connected between the second connection point and a negative direct current pole (dc-), a resistance arrangement (Rbrk) connected between the first connection point and the second connection point, and a control arrangement (11) configured to, in response to detecting a fault in the resistance arrangement (Rbrk), control the second controllable semiconductor switch (T2) and the third controllable semiconductor switch (T3) into a conducting state.

The invention provides a control method and system for preventing overvoltage of an intermediate capacitor when a train passes through a non-power zone, and the method comprises the steps: S1, monitoring the running speed of the train in real time, and executing S2 when the speed is lower than a preset threshold value and a traction system diagnoses an undervoltage fault; s2, detecting whether the voltage of the intermediate capacitor reaches a chopping opening threshold or not in the network voltage recovery process, and if yes, executing S3; and S3, opening a brake chopper tube and starting a time control mechanism, including single chopping opening time and accumulated chopping time in the whole process from undervoltage to network voltage recovery, and performing parallel judgment in the chopping process: when the single chopping time exceeds first allowable time or the accumulated chopping time exceeds second allowable time, immediately closing the chopper tube. Through a dual-time control mechanism, overvoltage of the intermediate capacitor is effectively prevented under the condition that the brake resistor does not have forced air cooling, smooth transition of a system from a non-power area to a power area is ensured, and the overvoltage protection problem caused by forbidding of a micro-brake function under the low-speed working condition is solved.