Bidirectional transducer of flywheel energy storage system and control method of bidirectional transducer

Abstract

The invention discloses a bidirectional transducer of a flywheel energy storage system and a control method of the bidirectional transducer. The bidirectional transducer of the flywheel energy storage system comprises a three-phase bridge arm and a neutral point bridge arm which is in parallel connection with the three-phase bridge arm. The neutral point bridge arm is connected with the neutral point of a motor winding. According to the bidirectional transducer of the flywheel energy storage system and the control method of the bidirectional transducer, a flywheel can reach a higher rotating speed in the charging process, and accordingly the amplitude of induced electromotive force is raised; the requirement for boosting of half bridge modulation can be lowered in the discharging process, so that energy feedback is better achieved; in addition, the energy storage capacity of the flywheel energy storage system can be improved through the higher rotating speed, single and double pole driving can be realized, and smooth switching can be achieved between the two driving modes; the bidirectional transducer of the flywheel energy storage system and the control method of the bidirectional transducer are suitable for the flywheel energy storage system and other occasions which are wide in operation range and capable of achieving frequent switching in a high / low velocity area, and particularly suitable for solving the randomness and volatility problems of a new energy power generation system, energy can be output smoothly, so that the change of the voltages, the frequencies and the phases of a power grid due to wind power generation is effectively adjusted, and large-scale new energy electricity can be safely and reliably connected into a conventional power grid.

Description

technical field [0001] The invention relates to a bidirectional converter and a control method thereof, in particular to a flywheel energy storage system bidirectional converter suitable for driving by a brushless DC motor and capable of single and bipolar driving and a control method thereof. Background technique [0002] With the development of technology and the continuous reduction of cost, the installed capacity of wind power and solar power is developing rapidly at a rate of 30% per year. However, the inherent randomness and intermittent characteristics of wind energy and solar energy have seriously affected the peak regulation of the power grid and the safe operation of the system, restricting the ability of the power grid to accept new energy. [0003] The flywheel energy storage system drives a flywheel body with a large moment of inertia by the drive motor, and charges and discharges energy through acceleration or deceleration. Brushless DC motors have high torque...

AI Technical Summary

Problems solved by technology

[0004] In the operating range of the flywheel energy storage system, when the energy on the DC bus needs to be compensated for electric energy, if the brushless DC motor discharges freely, the lower electromotive force cannot transmit energy to the higher DC bus

The boosting capacity of the existing technology is limited, especially when the flywheel is near the minimum operating speed, a duty cycle close to 1 is required, and the power feeding may even fail, threatening the safety of the entire new energy power generation system

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