Pulse-driving digital logic circuit used for serial triggering of high-voltage thyristor valve

Abstract

The invention relates to a thyristor valve in a power grid and electric power system, and particularly relates to improvement of a pulse-driving digital logic circuit used for serial triggering of a high-voltage thyristor valve. The pulse-driving digital logic circuit comprises a crystal oscillator U1, a normal triggering demagnetizing pulse generating unit and a reverse triggering demagnetizing pulse generating unit, wherein the normal triggering demagnetizing pulse generating unit also comprises three D triggers, a first NOR gate U4, a third NOT gate U12, six AND gates, a first delay circuit U18, a first NAND gate U20,a first fault detection unit MK1 and a second fault detection unit MK2; and the reverse triggering demagnetizing pulse generating unit also comprises three D triggers, a second NOR gate U4, a fourth NOT gate U13, six AND gates, a second delay circuit U19, a second NAND gate U21, a third fault detection unit MK3 and a fourth fault detection unit MK 4. The invention provides the pulse-driving digital logic circuit used for serial triggering of a high-voltage thyristor valve, which is stronger in adaptability to input signals, is added with a dead zone control function, and has the functions of detection feedback and logic fault judgment.

Description

technical field [0001] The invention relates to a thyristor valve used in power grids and power systems, in particular to the improvement of pulse-driven digital logic circuits used for triggering high-voltage thyristor valve strings. Background technique [0002] In recent years, thyristor soft grid-connected devices and static dynamic reactive power compensation devices have been widely used in wind power generation systems. Thyristors are the core power electronic devices, and the trigger protection technology for thyristors constitutes the core technology of such power electronic devices. [0003] The function of the pulse-driven digital logic circuit triggered by the high-voltage thyristor valve string is: [0004] (1) Convert the input single-pulse signal into a high-frequency triggering and degaussing pulse train signal that is suitable for the high-power thyristor valve string triggering of the pulse transformer isolation type and has an equal action time. [0005] ...

AI Technical Summary

Problems solved by technology

[0016] (2) The output signal of this circuit: between the forward series trigger pulse train output terminal PTO and the forward series demagnetization pulse train output terminal PDO, between the reverse series trigger pulse train output terminal NTO and the reverse series demagnetization pulse train output terminal NDO, not Adding the dead zone control time, if the rear stage is equipped with a bridge drive power amplifier circuit, it will cause the fault damage of the upper and lower bridge arms of the successful discharge tube.

[0017] (3) Without the function of detection feedback and fault logic judgment, it will cause the problem that the fault of the trigger circuit cannot be detected accurately in real time, so that after a fault occurs in the trigger circuit of a certain phase, the system will continue to operate with the fault, which will cause three-phase imbalance or Positive and negative half-cycle imbalance and other damages will expand the fault range

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