Bidirectional power source of small spherical Tokamak ohm magnet

Abstract

The invention discloses a bidirectional power source of a small spherical Tokamak ohm magnet, belonging to the technical field of magnetic confinement fusion. The bidirectional power source consists of two capacitor groups, four IGBT (Insulated Gate Bipolar Transistor) switch modules, two diodes, a large-power non-inductive resistor and a first magnetic field coil. The bidirectional power source disclosed by the invention has the advantages that by using the four parallel-connected IGBT switch modules as a large-current (100 kA) switch, the bidirectional power source has the characteristics of simple and compact structure, convenience for driving, reliability in working and free maintenance; a waveform has no need of being adjusted by changing duty ratio, and the interference brought by frequently switching with a large current is eliminated; and the technical requirement on parallel connection of the IGBT switch modules is greatly reduced by only switching on and off the four IGBT switch modules once, so that the reliability is further improved.

Description

technical field [0001] The invention belongs to the technical field of magnetic confinement fusion, in particular to a bidirectional power supply for a small spherical tokamak ohmic magnet, in particular to a bidirectional power supply suitable for a small spherical tokamak air core ohmic magnet. Background technique [0002] The main function of the tokamak ohmic magnet is to generate a changing magnetic field, induce a toroidal electric field, break down the gas, heat the plasma and drive the toroidal plasma current. The time integral of the hoop voltage provided by an ohmic magnet is called volt-seconds, which is a major indicator of the performance of an ohmic magnet. Volt-seconds depend on how much the magnetic field changes. In most current tokamak devices, in order to make full use of the current capacity of the ohmic magnet coil, the coil current can swing from a positive maximum allowable value to a negative maximum allowable value, that is, bidirectional discharge...

AI Technical Summary

Problems solved by technology

The main disadvantages of this circuit: the ignition tube used as a switch is a non-solid component with short life, mercury, and needs maintenance; the trigger sequence and reliability of the four high-current switches must be strictly guaranteed, otherwise it will lead to serious accidents, such as: work During the process, if the second switch Ig2 is not turned on normally, a very high induced voltage will be generated on the second magnetic field coil L2; if the third ignition tube Ig3 and the fourth ignition tube Ig4 are opened in advance, it will cause the fourth Capacitor C4 and fifth capacitor C5 are short-circuited

The main disadvantage of this circuit: only one group of capacitors are used for power supply, and four high-current switches must be turned on and off at high frequency by adjusting the duty cycle to achieve waveforms with different rates of change; Frequent switching on and off not only brings great interference to the surrounding environment, but also requires the use of a bulky absorption and buffer circuit (consisting of the second resistor R2 and the third resistor R3), and also increases the technology of equalizing the current of each parallel IGCT difficulty

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