6results about How to "Small starting current" patented technology

A control method for slow variable-power start-up of a scraper conveyor includes: controlling the start-up of the motors at the head and tail of the scraper conveyor in four stages: In the first stage, the conveyor starts from zero speed and accelerates uniformly until the output torque of the head motor reaches a first torque threshold, at which point it enters the second stage; in the second stage, the conveyor moves at a uniform speed at the speed at which it entered the second stage, until the chain tension reaches a tension threshold, at which point it enters the third stage; in the third stage, the conveyor uses the speed at which it entered the third stage as the initial speed, gradually increasing acceleration, and then gradually decreasing acceleration until the output torque of the head motor reaches a second torque threshold, at which point it enters the fourth stage; and in the fourth stage, the conveyor moves at a uniform speed at the speed at which it entered the fourth stage. This method can reduce the number of chain tension peaks and the vibration frequency.

The utility model relates to the technical field of generators, in particular to an emergency power supply system. The emergency power supply system comprises a variable frequency motor, a reverse dragging control module, an inverter, a power part and an energy storage battery, a rotor of the variable frequency motor is in transmission connection with the power part; the output end of the variable frequency motor is electrically connected with the input end of the inverter; the reverse dragging control module is electrically connected with the variable frequency motor and the inverter and is in communication connection with the inverter. The inverter is electrically connected with the power part and the energy storage battery, the generator can be started without starting a motor, the starting current is small, and the problems that the load cannot be carried due to instant overload of the generator and the energy use efficiency is low can be solved.

This disclosure provides embodiments of a black-start system, black-start method, and medium suitable for pure hydrogen gas turbine units. One specific embodiment of the black-start system includes: a control device communicatively connected to the power grid, a frequency converter, the pure hydrogen gas turbine unit, and a diesel generator; a hydrogen storage device is pipe-connected to the pure hydrogen gas turbine unit; the control device is configured to control the diesel generator to perform a start-up operation; the frequency converter includes a rectifier assembly and an inverter assembly; the control device is configured to determine switching frequency information based on parameter information; invert the rectified DC power; the control device is configured to control the pure hydrogen gas turbine unit to perform an operating operation; the pure hydrogen gas turbine unit is electrically connected to the power grid; the control device is also configured to control the diesel generator to perform a shutdown operation and to control the pure hydrogen gas turbine unit to continue operating. This embodiment can improve the safety and reliability of the black-start system.

A feeder for reducing the pressure of grain on a grain dispensing system includes a grain storage device for holding grain, a grain outlet for grain outflow, and a grain dispensing system disposed within the grain storage device to intermittently guide grain into the outlet. A grain retainer is also disposed within the grain storage device, shielding the grain dispensing system, and the orthographic projection of the retainer towards the grain dispensing system covers the system. At least one leakage port is provided on the retainer for grain to leak out towards the grain dispensing system. This technical solution reduces the resistance of the grain within the grain storage device to the grain dispensing system when the system is activated, effectively protecting the normal operation of the grain dispensing system and extending its service life.

This invention belongs to the technical field of temperature control methods for fiber laser chillers, and particularly relates to a method for controlling the low-temperature outlet water temperature of a chiller based on a bypass valve and a compressor misalignment switch. The method includes the following steps: determining the preset temperature, temperature control accuracy, and accuracy coefficient; closing the bypass valve; starting the chiller and compressor normally; continuously monitoring the actual low-temperature outlet water temperature after the chiller starts running; and combining control of the compressor and bypass valve according to different states to maintain the low-temperature outlet water temperature within a reasonable range. This application, based on the changes in the low-temperature outlet water temperature of the chiller, utilizes a combination of compressor start control and bypass valve on / off control to achieve rapid balance of high and low pressure differences, creating conditions for the next compressor start-up more efficiently and accurately, reducing the starting current, and simultaneously improving the temperature control accuracy of the chiller water. This avoids the problem of frequent laser alarms and malfunctions due to excessive water temperature fluctuations in complex environments.

The application discloses an automatic mechanism sand production device and belongs to the technical field of mechanism sand production. The device comprises a sieve box, an exciting shaft, a rotating disc and a motor, a radial sliding slot is formed in the rotating disc, a counterweight block is slidably arranged in the sliding slot, and a return spring is arranged between the counterweight block and the bottom of the sliding slot. The centrifugal force received by the counterweight block when the exciting shaft rotates is balanced with the elastic force of the return spring. When the load change causes the rotating speed fluctuation, the counterweight block automatically slides in the radial direction to change the eccentric distance, so that the exciting force size is adjusted, and the rotating speed negative feedback stability mechanism is formed. The application can realize the self-adaptive adjustment of the exciting force with the load without a sensor and a controller, effectively reduces the starting current, stabilizes the screening efficiency, prolongs the service life of the equipment, and has the advantages of simple structure and high reliability.