CN107706892B - Method and device for determining parameters of alternating current rapid switching device based on thyristor - Google Patents

Abstract

The invention provides a method and a device for determining parameters of an alternating current fast switching device based on a thyristor, which are used for determining the turn-on time of the alternating current fast switching device according to the trigger delay time of thyristors in a third thyristor module and a fourth thyristor module in a bidirectional turn-on branch circuit, and determining the turn-off time of the alternating current fast switching device according to the turn-off time of a first stage and the turn-off time of a second stage, so that the turn-on time and the turn-off time of the alternating current fast switching device are determined. The technical scheme provided by the invention can realize the millisecond-level connection and disconnection of the alternating current quick switching device, so that the millisecond-level quick switching of an alternating current line is realized, and the connection and disconnection operation time can reach 1 ms; in addition, the core devices in the technical scheme provided by the invention adopt thyristors and diodes, so that the back voltage resistance and current resistance levels are high; the power supply in the technical scheme provided by the invention adopts an alternating current power supply, so that the on-site power supply is convenient, the installation of the device is convenient, and the requirements of different application scenes can be met.

Description

Method and device for determining parameters of alternating current rapid switching device based on thyristor

Technical Field

The invention relates to the technical field of power electronics, in particular to a method and a device for determining parameters of an alternating current rapid switching device based on a thyristor.

Background

The alternating current switch is a key device in the power system, has the main function of conducting and switching off the branch, and plays an important role in the aspects of cutting off disturbance sources of the power system, quickly cutting off loads, preventing fault expansion of the power system and the like.

The safety and stability of the power grid have three defense lines which are respectively: firstly, a first defense line is used for accurately cutting off relay protection of a fault element at a high speed and reacting protection of abnormal operation of protected equipment without losing load, and quickly isolating faults; secondly, a second line of defense is provided, which allows a small amount of load to be lost for a safety automatic device for ensuring the safe operation of the power grid, and avoids element overload and power grid instability; and thirdly, adopting all necessary means for out-of-step disconnection and frequency and voltage control to avoid the breakdown of the power grid. The three defense lines respectively relate to three key conditions of whether a fault source can be quickly cut off, whether a load can be accurately and quickly cut off and whether a key section can be quickly cut off, and the three key conditions are met and the alternating current switch can quickly act.

The faster the AC switch action time is, the more the safety and stability of the power system can be guaranteed. At present, an alternating current high-voltage switch is a mechanical switch, alternating current needs to be waited to flow through a zero point when the alternating current is turned off, the mechanical switch can act when the alternating current flows through the zero point, the disconnection speed of a mechanical element is slow, and the total turning-off operation time is generally 40-60 milliseconds or even longer. The action time of the alternating current mechanical switch is slow, which is not beneficial to the safe and stable operation of the power system, and the requirements of different application scenes can not be met. There is no research in the prior art relating to thyristor-based ac fast switching devices and parameter determination of thyristor-based ac fast switching devices.

Disclosure of Invention

In order to overcome the defects that a mechanical switch in the prior art is not beneficial to safe and stable operation of a power system due to slow action time and cannot meet the requirements of different application scenes, the invention provides a method and a device for determining parameters of an alternating current quick switching device based on a thyristor, wherein the alternating current quick switching device based on the thyristor comprises a bidirectional conduction branch circuit for realizing bidirectional conduction of working current of an alternating current circuit; the forced transfer branch circuit is used for transferring the current of the alternating current circuit in the bidirectional conduction branch circuit to the forced transfer branch circuit and reducing the current of the alternating current circuit transferred to the forced transfer branch circuit to a zero point; and the power supply and discharge branch circuit is used for supplying power to the capacitor in the forced transfer branch circuit, realizing the discharge of the current of the alternating current line and finally realizing the millisecond-level switching-on and switching-off of the alternating current fast switching device, wherein in the parameter determination method of the thyristor-based alternating current fast switching device, the switching-on time of the alternating current fast switching device is determined according to the trigger delay time of the thyristors in the third thyristor module and the fourth thyristor module in the bidirectional switching-on branch circuit, the switching-off time of the alternating current fast switching device is determined according to the first-stage switching-off time and the second-stage switching-off time, and the determination of the switching-on time and the switching-off time of the alternating current fast switching device is realized.

In order to achieve the purpose of the invention, the invention adopts the following technical scheme:

the invention provides a method for determining parameters of an alternating current quick switching device based on a thyristor, wherein the alternating current quick switching device comprises the following steps:

the bidirectional conduction branch is used for realizing bidirectional conduction of working current of the alternating current line;

the forced transfer branch circuit is used for transferring the current of the alternating current circuit in the bidirectional conduction branch circuit to the forced transfer branch circuit and reducing the current of the alternating current circuit transferred to the forced transfer branch circuit to a zero point;

the power supply and discharge branch circuit is used for supplying power to the capacitor in the forced transfer branch circuit and realizing the discharge of the current of the alternating current circuit;

the parameter determination method comprises the following steps:

determining the on-time of the alternating current fast switching device according to the trigger delay time of thyristors in a third thyristor module and a fourth thyristor module in the bidirectional conducting branch, and determining the off-time of the alternating current fast switching device according to the first-stage off-time and the second-stage off-time;

the first-stage turn-off time is determined according to the inductance value of the first inductance module in the forced transfer branch and the capacitance value of the capacitor;

and the turn-off time of the second stage is determined according to the inductance value of the second inductance module in the forced transfer branch circuit and the capacitance value of the capacitor.

The forced transfer branch comprises a capacitor, a first transfer module and a second transfer module;

the first transfer module comprises a first thyristor module, a first resistance module and a first inductance module which are connected in series;

the second transfer module comprises a second thyristor module, a second resistor module and a second inductor module which are connected in series;

the first thyristor module and the second thyristor respectively comprise a plurality of thyristors which are connected in series, parallel or combination of series and parallel;

the cathodes of the thyristors in the first thyristor module face to the node N1, and the anodes face to the second transfer module;

the cathodes of the thyristors in the second thyristor module are all facing node N2, and the anodes are facing the first transfer module.

The power supply and discharge branch circuit is connected with a capacitor in the forced transfer branch circuit in parallel and comprises a third resistance module, a third inductance module, a full-bridge module and a power supply;

the full-bridge module comprises a first bridge arm module and a second bridge arm module which are connected in series, and a third bridge arm module and a fourth bridge arm module which are connected in series;

the third resistance module and the third inductance module are connected in series;

the first resistance module, the second resistance module and the third resistance module respectively comprise a plurality of resistances which are connected in series, in parallel or in combination of series and parallel;

the first inductor module, the second inductor module and the third inductor module respectively comprise a plurality of inductors, and the plurality of inductors are connected in series, in parallel or in combination of series and parallel.

The first bridge arm module and the second bridge arm module respectively comprise a plurality of diodes which are connected in series, in parallel or in series-parallel;

the third bridge arm module and the fourth bridge arm module respectively comprise a plurality of thyristors which are connected in series, in parallel or in series-parallel;

cathodes of all diodes in the first bridge arm module are connected with a common point G between the first bridge arm module and the second bridge arm module, and anodes of all diodes are connected with a common point A between the first bridge arm module and the third bridge arm module;

cathodes of all diodes in the second bridge arm module are connected with a common point K between the second bridge arm module and the fourth bridge arm module, and anodes of all diodes are connected with a common point A between the first bridge arm module and the second bridge arm module;

cathodes of all thyristors in the third bridge arm module are connected with a common point Y between the third bridge arm module and the fourth bridge arm module, and anodes of all thyristors are connected with a common point G between the first bridge arm module and the third bridge arm module;

cathodes of all thyristors in the fourth bridge arm module are connected with a common point Y between the second bridge arm module and the fourth bridge arm module, and anodes of all thyristors are connected with a common point K between the third bridge arm module and the fourth bridge arm module.

The bidirectional conduction branch comprises a first bidirectional conduction module and a second bidirectional conduction module which are connected in series;

the first bidirectional switch-on module comprises a first diode module and a third thyristor module which are connected in parallel;

the second bidirectional conducting module comprises a second diode module and a fourth thyristor module which are connected in parallel;

the first diode module and the second diode module respectively comprise a plurality of diodes, and the plurality of diodes are connected in series, in parallel or in combination of series and parallel;

the third thyristor module and the fourth thyristor module both comprise a plurality of thyristors which are connected in series, parallel or combination of series and parallel;

the anodes of the diodes in the first diode module face to the node N1, and the cathodes of the diodes face to the second bidirectional conduction module;

the cathodes of the thyristors in the third thyristor module face to the node N1, and the anodes of the thyristors in the third thyristor module face to the second bidirectional conduction module;

the anodes of the diodes in the second diode module face to the node N2, and the cathodes of the diodes face to the first bidirectional conduction module;

the cathodes of the thyristors in the fourth thyristor module are all facing the node N2, and the anodes thereof are all facing the first bidirectional conducting module.

The common point A is connected with a common point J between the first bidirectional conduction module and the second bidirectional conduction module through a third resistance module and a third inductance module which are connected in series, and the common point Y is connected with a common point F between the first current limiting module and the second current limiting module;

one end of the capacitor is connected with the common point J, and the other end of the capacitor is connected with the common point F;

and one end of the power supply is connected with the common point K, and the other end of the power supply is connected with the common point G.

The conduction time of the alternating current fast switching device is calculated according to the following formula:

T_on＝T_delay

wherein, T_onIndicating the on-time, T, of the AC fast switching device_delayIs the trigger delay time of the thyristor.

The determining the turn-off time of the alternating current fast switching device according to the first-stage turn-off time and the second-stage turn-off time includes:

the turn-off time of the ac fast switching device is calculated as follows:

T_off＝T_off1+T_off2

wherein, T_offRepresents the turn-off time of the AC fast switching device, and T_off≤T_{off_max}，T_{off_max}Represents the maximum turn-off time, T, of the AC quick-switching device that the AC system can withstand_off1Denotes the first stage off time, T_off2Indicating a second stage off time.

T is calculated as follows_off1：

Where ω' represents the angular frequency of oscillation of the first stage, calculated as:

wherein C represents the capacitance value of the capacitor in the forced transfer branch, L₁And R₁Are all intermediate in quantity, and

L₁calculated as follows:

L₁＝(L₂₁+L₂₂)/2

wherein L is₂₁Representing the inductance, L, of the first inductor module₂₂Representing an inductance value of the second inductance module;

R₁calculated as follows:

R₁＝(R₂₁+R_{on_eq21}+R₂₂+R_{on_eq22})/2

wherein R is₂₁Representing the resistance, R, of the first resistor module₂₂Representing the resistance, R, of the second resistor module_{on_eq21}Represents the sum of the on-resistances of the thyristor and the diode when both the thyristor in the first thyristor module and the diode in the first diode module are on, R_{on_eq22}Representing the sum of the on-resistances of the thyristor and the diode when both the thyristor in the second thyristor module and the diode in the second diode module are on.

T is calculated as follows_off2：

Where ω "represents the oscillation angular frequency of the second stage, calculated as:

wherein C represents the capacitance value of the capacitor in the forced transfer branch, L₂And R₂Are all intermediate in quantity, and

L₂calculated as follows:

L₂＝L_eq+L_s

wherein L is_eqIs an intermediate amount, L_eqIs equal to L₂₁Or L₂₂，L_sThe equivalent inductance of an alternating current system connected with the alternating current fast switching device is represented;

R₂calculated as follows:

R₂＝R_S+R_{on_eq}

wherein R is_SRepresenting the equivalent resistance, R, of an AC system to which the AC fast switching device is connected_{on_eq}Is an intermediate amount, R_{on_eq}Is equal to R_{on_eq21}Or R_{on_eq22}。

The parameter determination method further includes determining L of the formula₂₁And L₂₂The value range of (A):

wherein, I_maxIndicating the maximum cis-state current, U, that the AC fast switching device can withstand₀Representing the DC voltage supplied to the capacitor by the supply and bleed branches, a and b being intermediate quantities, an

C₀Representing the lower limit of the capacitance value of the capacitor in the forced transfer branch.

The invention also provides a parameter determination device of the thyristor-based alternating current fast switching device, which comprises the following components:

the first determining module is used for determining the turn-on time of the alternating current fast switching device according to the trigger delay time of the thyristors in the third thyristor module and the fourth thyristor module and determining the turn-off time of the alternating current fast switching device according to the turn-off time of the first stage and the turn-off time of the second stage;

the first-stage turn-off time is determined according to the inductance value of the first inductance module and the capacitance value of the capacitor in the forced transfer branch circuit;

and the turn-off time of the second stage is determined according to the inductance value of the second inductance module and the capacitance value of the capacitor in the forced transfer branch circuit.

The first determining module comprises a first determining unit, and the first determining unit calculates the conducting time of the alternating current fast switching device according to the following formula:

T_on＝T_delay

wherein, T_onIndicating the on-time, T, of the AC fast switching device_delayIs the trigger delay time of the thyristor.

The first determination module comprises a second determination unit, and the second determination unit calculates the turn-off time of the alternating current fast switching device according to the following formula:

T_off＝T_off1+T_off2

wherein, T_offRepresents the turn-off time of the AC fast switching device, and T_off≤T_{off_max}，T_{off_max}Represents the maximum turn-off time, T, of the AC quick-switching device that the AC system can withstand_off1Denotes the first stage off time, T_off2Indicating a second stage off time.

The second determining unit is specifically configured to:

t is calculated as follows_off1：

Where ω' represents the angular frequency of oscillation of the first stage, calculated as:

wherein C represents the capacitance value of the capacitor in the forced transfer branch, L₁And R₁Are all intermediate in quantity, and

L₁calculated as follows:

L₁＝(L₂₁+L₂₂)/2

wherein L is₂₁Representing the inductance, L, of the first inductor module₂₂Representing an inductance value of the second inductance module;

R₁calculated as follows:

R₁＝(R₂₁+R_{on_eq21}+R₂₂+R_{on_eq22})/2

wherein R is₂₁Representing the resistance, R, of the first resistor module₂₂Representing the resistance, R, of the second resistor module_{on_eq21}Represents the sum of the on-resistances of the thyristor and the diode when both the thyristor in the first thyristor module and the diode in the first diode module are on, R_{on_eq22}Representing the sum of the on-resistances of the thyristor and the diode when both the thyristor in the second thyristor module and the diode in the second diode module are on.

The second determining unit is specifically configured to:

t is calculated as follows_off2：

Where ω "represents the oscillation angular frequency of the second stage, calculated as:

wherein C represents the capacitance value of the capacitor in the forced transfer branch, L₂And R₂Are all intermediate in quantity, and

L₂calculated as follows:

L₂＝L_eq+L_s

wherein L is_eqIs an intermediate amount, L_eqIs equal to L₂₁Or L₂₂，L_sThe equivalent inductance of an alternating current system connected with the alternating current fast switching device is represented;

R₂calculated as follows:

R₂＝R_S+R_{on_eq}

wherein R is_SRepresenting the equivalent resistance, R, of an AC system to which the AC fast switching device is connected_{on_eq}Is an intermediate amount, R_{on_eq}Is equal to R_{on_eq21}Or R_{on_eq22}。

The parameter determination apparatus further comprises a second determination module for determining L of the formula₂₁And L₂₂The value range of (A):

wherein, I_maxIndicating the maximum cis-state current, U, that the AC fast switching device can withstand₀Representing the DC voltage supplied to the capacitor by the supply and bleed branches, a and b being intermediate quantities, an

Wherein C is₀Representing the lower limit of the capacitance value of the capacitor in the forced transfer branch.

Compared with the closest prior art, the technical scheme provided by the invention has the following beneficial effects:

the thyristor-based alternating current fast switching device comprises a bidirectional conduction branch circuit, a bidirectional conduction branch circuit and a bidirectional conduction branch circuit, wherein the bidirectional conduction branch circuit is used for realizing bidirectional conduction of working current of an alternating current circuit; the forced transfer branch circuit is used for transferring the current of the alternating current circuit in the bidirectional conduction branch circuit to the forced transfer branch circuit and reducing the current of the alternating current circuit transferred to the forced transfer branch circuit to a zero point; the power supply and discharge branch circuit is used for supplying power to the capacitor in the forced transfer branch circuit, realizing the discharge of the current of the alternating current circuit and finally realizing the millisecond-level conduction and the shutdown of the alternating current quick switching device;

according to the parameter determination method of the thyristor-based alternating current fast switching device, the on time of the alternating current fast switching device can be determined according to the trigger delay time of the thyristors in the third thyristor module and the fourth thyristor module in the bidirectional conducting branch, the off time of the alternating current fast switching device can be determined according to the first-stage off time and the second-stage off time, and the on time and the off time of the alternating current fast switching device can be determined;

according to the technical scheme provided by the invention, a first transfer module and a second transfer module both adopt thyristors and resistors which are connected in series, the first bridge arm module and the second bridge arm module both adopt diodes, the third bridge arm module and the fourth bridge arm module both adopt thyristors, and the first bidirectional conduction module and the second bidirectional conduction module are both provided with the diodes and the thyristors which are connected in parallel, millisecond-level conduction and disconnection of the alternating current quick switching device are realized through the series-parallel connection relation between the devices, so that millisecond-level quick switching of an alternating current line is realized, and the operation time of conduction and disconnection can reach 1 ms;

the core devices in the technical scheme provided by the invention adopt the thyristors and the diodes, so that the back voltage resistance and the current resistance are high;

the power supply in the technical scheme provided by the invention adopts an alternating current power supply, so that the on-site power supply is convenient, the installation of the device is convenient, and the requirements of different application scenes can be met.

Drawings

Fig. 1 is a structural diagram of a thyristor-based ac fast switching apparatus according to embodiment 1 of the present invention;

fig. 2 is a structural diagram of a thyristor-based ac fast switching apparatus according to embodiment 2 of the present invention;

fig. 3 is a wiring diagram of an ac fast switching apparatus applied to a three-phase ac system in embodiment 2 of the present invention;

fig. 4 is a flowchart of a parameter determination method for a thyristor-based ac fast switching device in embodiment 3 of the present invention.

Fig. 5 is an equivalent topology diagram of the ac fast switching apparatus in the first stage according to embodiment 3 of the present invention;

fig. 6 is an equivalent topology diagram of the ac fast switching apparatus in the second stage according to embodiment 3 of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

Thyristors are short for thyristors and are also called thyristors. The thyristor can work under the conditions of high voltage and large current, and the working process of the thyristor can be controlled, so that the thyristor can be widely applied to electronic circuits such as controllable rectification, alternating current voltage regulation, inversion, frequency conversion and the like.

An embodiment 1 of the present invention provides an ac fast switching apparatus based on the thyristor, and a specific structure diagram of the ac fast switching apparatus is shown in fig. 1, where C in fig. 1 represents a capacitor in a forced transfer branch, N1 and N2 represent two nodes on an ac line where the ac fast switching apparatus is located, and the two nodes include a bidirectional conducting branch, a forced transfer branch, and a power supply branch and a discharging branch, and functions of the three branches are described below:

the bidirectional conduction branch circuit is used for realizing bidirectional conduction of working current of the alternating current line;

the forced transfer branch circuit is used for transferring the current of the alternating current circuit in the bidirectional conduction branch circuit to the forced transfer branch circuit and reducing the current of the alternating current circuit transferred to the forced transfer branch circuit to a zero point; and

the power supply and discharge branch circuit is used for supplying power to the capacitor in the forced transfer branch circuit and realizing the discharge of the current of the alternating current line.

The forced transfer branch comprises a first transfer module and a second transfer module besides a capacitor C;

the first transfer module comprises a first thyristor module, a first resistance module and a first inductance module which are connected in series;

the second transfer module comprises a second thyristor module, a second resistor module and a second inductor module which are connected in series;

the first thyristor module and the second thyristor respectively comprise a plurality of thyristors which are connected in series, parallel or combination of series and parallel; the cathodes of the thyristors in the first thyristor module face the node N1, and the anodes face the second transfer module; the cathodes of the thyristors in the second thyristor module are all facing node N2, and the anodes are facing the first transfer module.

The first resistance module and the second resistance module respectively comprise a plurality of resistances which are connected in series, in parallel or in combination of series and parallel.

The first inductance module and the second inductance module respectively comprise a plurality of inductances, and the inductances are connected in series, in parallel or in combination of series and parallel.

The power supply and discharge branch is connected with a capacitor C in the forced transfer branch in parallel, and comprises a third resistance module, a third inductance module, a full-bridge module and a power supply;

the third resistor modules comprise a plurality of resistors which are connected in series, in parallel or in combination of series and parallel;

the third inductance modules comprise a plurality of inductances, and the inductances are connected in series, parallel or combination of series and parallel.

The full-bridge module comprises a first bridge arm module, a second bridge arm module, a third bridge arm module and a fourth bridge arm module, wherein the first bridge arm module is connected with the second bridge arm module in series, the third bridge arm module is connected with the fourth bridge arm module in series, and the third resistance module is connected with the third inductance module in series.

The first bridge arm module and the second bridge arm module respectively comprise a plurality of diodes which are connected in series, in parallel or in series-parallel combination;

the third bridge arm module and the fourth bridge arm module respectively comprise a plurality of thyristors which are connected in series, in parallel or in series-parallel.

The connection relations of the devices in the first bridge arm module, the second bridge arm module, the third bridge arm module and the fourth bridge arm module in the full bridge module are as follows:

1) cathodes of all diodes in the first bridge arm module are connected with a common point G between the first bridge arm module and the second bridge arm module, and anodes of all diodes are connected with a common point A between the first bridge arm module and the third bridge arm module;

2) cathodes of all diodes in the second bridge arm module are connected with a common point K between the second bridge arm module and the fourth bridge arm module, and anodes of all diodes are connected with a common point A between the first bridge arm module and the second bridge arm module;

3) cathodes of all thyristors in the third bridge arm module are connected with a common point Y between the third bridge arm module and the fourth bridge arm module, and anodes of all thyristors are connected with a common point G between the first bridge arm module and the third bridge arm module;

4) cathodes of all thyristors in the fourth bridge arm module are connected with a common point Y between the second bridge arm module and the fourth bridge arm module, and anodes of all thyristors are connected with a common point K between the third bridge arm module and the fourth bridge arm module.

The bidirectional conduction branch comprises a first bidirectional conduction module and a second bidirectional conduction module which are connected in series;

the first bidirectional switch-on module comprises a first diode module and a third thyristor module which are connected in parallel;

the second bidirectional conducting module comprises a second diode module and a fourth thyristor module which are connected in parallel;

the first diode module and the second diode module comprise a plurality of diodes, and the plurality of diodes are connected in series, in parallel or in combination of series and parallel;

the third thyristor module and the fourth thyristor module both comprise a plurality of thyristors, and the plurality of thyristors are connected in series, parallel or combination of series and parallel.

1. The orientation of the diodes in the first diode module and the second diode module is as follows:

1) the anodes of the diodes in the first diode module face the node N1, and the cathodes of the diodes face the second bidirectional conduction module;

2) the anodes of the diodes in the second diode module face the node N2, and the cathodes of the diodes face the first bidirectional conduction module;

2. the orientation of the transistors in the third thyristor module and the fourth transistor module is as follows:

1) the cathodes of the thyristors in the third thyristor module face the node N1, and the anodes face the second bidirectional conduction module;

2) the thyristors in the fourth thyristor module have their cathodes all facing node N2 and their anodes all facing the first bidirectional conducting module.

The common point A is connected with a common point J between the first bidirectional conduction module and the second bidirectional conduction module through a third resistance module and a third inductance module which are connected in series, and the common point Y is connected with a common point F between the first current limiting module and the second current limiting module; one end of the capacitor C is connected with the common point J, and the other end of the capacitor C is connected with the common point F;

one end of the power supply is connected with the common point K, and the other end of the power supply is connected with the common point G.

Embodiment 1 of the present invention further provides a control method for an ac fast switching device based on a thyristor, where the control method includes a specific turn-on control process and a turn-off control process of the ac fast switching device provided in embodiment 1 of the present invention, and the turn-on control process and the turn-off control process of the ac fast switching device are respectively described in detail below:

1. the conduction control process comprises the following steps:

continuously sending trigger signals to thyristors in a third thyristor module, a fourth thyristor module, a third full-bridge module and a fourth full-bridge module, and stopping sending the trigger signals to thyristors in a first transfer module and a second transfer module to realize the conduction control of the alternating-current rapid switching device;

2. the turn-off control process comprises the following steps:

and stopping sending trigger signals to thyristors in the first bidirectional conduction module, the second bidirectional conduction module, the third full-bridge module and the fourth full-bridge module, and sending trigger signals to thyristors in the first thyristor module and the second thyristor module to realize the turn-off control of the alternating current fast switching device, wherein the conduction time of the fast switching device is not more than 1 ms.

In the turn-off control process, after thyristors in the first thyristor module and the second thyristor module receive trigger signals, the current of an alternating current line in the two-way conduction branch circuit is transferred to the forced transfer branch circuit, and then is reduced to a zero point through the power supply and discharge branch circuit, thyristors in the first thyristor module, the second thyristor module, the third thyristor module and the fourth thyristor module are all in a turn-off state, the turn-off control of the alternating current fast switching device is realized, and the turn-off time of the fast switching device can be completed within 1 ms.

Example 2

Embodiment 2 of the present invention provides a thyristor-based ac fast switching apparatus, where a specific structure of the ac fast switching apparatus is as shown in fig. 2, C denotes a capacitor in a forced transfer branch, N1 and N2 denote two nodes on an ac line where the ac fast switching apparatus is located, S denotes a power supply in a charging branch, D11, D12, D31, D32, D33, and D34 are diodes, TH11, TH12, TH21, and TH22 are thyristors, R1, R21, and R22 are resistors, and L1, L21, and L22 are inductors; the alternating current fast switching device based on the controllable device provided by the embodiment 2 of the invention comprises a bidirectional conduction branch, a forced transfer branch and a charging branch, and the functions of the three branches are respectively explained in detail as follows:

the bidirectional conduction branch circuit is used for realizing bidirectional conduction of working current of the alternating current line;

the forced transfer branch circuit is used for transferring the current of the alternating current circuit in the bidirectional conduction branch circuit to the forced transfer branch circuit and reducing the current of the alternating current circuit transferred to the forced transfer branch circuit to a zero point; and

the power supply and discharge branch circuit is used for supplying power to the capacitor in the forced transfer branch circuit and realizing the discharge of the current of the alternating current line.

The forced transfer branch comprises a first transfer module and a second transfer module besides a capacitor C;

the first transfer module comprises a first thyristor module, a first resistance module and a first inductance module which are connected in series;

the second transfer module comprises a second thyristor module, a second resistor module and a second inductor module which are connected in series;

the first thyristor module comprises TH21, the cathodes of TH21 face to node N1, and the anodes face to the second transfer module;

the second thyristor module comprises TH22 with the cathode of TH22 facing node N2 and the anode facing the first transfer module.

The first resistance module includes R21 and the second resistance module includes R22.

The first inductor module comprises L21 and the second inductor module comprises L22.

The full-bridge module comprises a first bridge arm module, a second bridge arm module, a third bridge arm module and a fourth bridge arm module, wherein the first bridge arm module is connected with the second bridge arm module in series, the third bridge arm module is connected with the fourth bridge arm module in series, and the third resistance module is connected with the third inductance module in series.

The first leg module includes D31 and the second leg module includes D32.

The third leg module comprises TH31 and the fourth leg module comprises TH 32.

The connection relations of the devices in the first bridge arm module, the second bridge arm module, the third bridge arm module and the fourth bridge arm module in the full bridge module are as follows:

1) the cathode of D31 is connected with the common point G between the first bridge arm module and the second bridge arm module, and the anode of D31 is connected with the common point A between the first bridge arm module and the third bridge arm module;

2) the cathode of D32 is connected with the common point K between the second bridge arm module and the fourth bridge arm module, and the anode of D32 is connected with the common point A between the first bridge arm module and the second bridge arm module;

3) the cathode of the TH31 is connected with the common point Y between the third bridge arm module and the fourth bridge arm module, and the anode of the TH31 is connected with the common point G between the first bridge arm module and the third bridge arm module;

4) the cathode of TH32 is connected to the common point Y between the second leg module and the fourth leg module, and the anode of TH32 is connected to the common point K between the third leg module and the fourth leg module.

The bidirectional conduction branch comprises a first bidirectional conduction module and a second bidirectional conduction module which are connected in series;

the first bidirectional switch-on module comprises a first diode module and a third thyristor module which are connected in parallel;

the second bidirectional conducting module comprises a second diode module and a fourth thyristor module which are connected in parallel;

the first diode module comprises D11, the anodes of D11 face to the node N1, and the cathodes face to the second bidirectional conduction module;

the second diode module comprises D12, the anodes of D12 face to the node N2, and the cathodes face to the first bidirectional conduction module;

the third thyristor module comprises a TH11, the cathode of the TH11 faces to the node N1, and the anode faces to the second bidirectional conduction module;

the fourth thyristor module comprises TH12, the cathode of TH12 faces to node N2, and the anode faces to the first bidirectional conducting module.

The common point A is connected with a common point J between the first bidirectional conduction module and the second bidirectional conduction module through a third resistance module and a third inductance module which are connected in series, and the common point Y is connected with a common point F between the first current limiting module and the second current limiting module; one end of the capacitor C is connected with the common point J, and the other end of the capacitor C is connected with the common point F;

one end of the power supply is connected with the common point K, and the other end of the power supply is connected with the common point G.

Embodiment 2 of the present invention further provides a control method for an ac fast switching device based on a thyristor, where the control method includes a specific turn-on control process and a turn-off control process of the ac fast switching device provided in embodiment 2 of the present invention, and the turn-on control process and the turn-off control process of the ac fast switching device are respectively described in detail below:

1. the conduction control process comprises the following steps:

continuously sending trigger signals to TH11, TH12, TH31 and TH32, and stopping sending the trigger signals to TH21 and TH22, so as to realize the conduction control of the AC fast switching device;

2. the turn-off control process comprises the following steps:

and stopping sending the trigger signals to TH11, TH12, TH31 and TH32, and sending the trigger signals to TH21 and TH22, so as to realize the turn-off control of the alternating current fast switching device, wherein the turn-on time of the fast switching device is not more than 1 ms.

In the turn-off control process, after the TH21 and the TH22 receive the trigger signals, the current of the alternating current line in the bidirectional conduction branch is transferred to the forced transfer branch, and then is reduced to a zero point through the power supply branch and the discharge branch, the TH11, the TH12, the TH21 and the TH22 are all in a turn-off state, the turn-off of the electrical connection of the alternating current circuit between the node N1 and the node N2 is realized, namely the turn-off control of the alternating current fast switching device is realized, and the turn-off time of the fast switching device can be completed within 1 ms.

As shown in fig. 3, the ac fast switching apparatus provided in embodiment 2 of the present invention can be applied to a three-phase ac system. The three AC fast switching devices are respectively connected into a three-phase AC line in a series mode, wherein B represents an AC fast switch, N1 and N2 both represent nodes, and specifically, N1 and N2 are connection ports of the AC line connected in series with the AC fast switching devices. A1 and A2 are nodes on an A alternating current line, and form an A1-A2 line; b1 and B2 are nodes on a B alternating current line, and form a B1-B2 line; c1 and C2 are nodes on the C AC line, forming a C1-C2 line.

Example 3

Embodiment 3 of the present invention provides a method for determining parameters of an ac fast switching device based on a thyristor, where the ac fast switching device in embodiment 1 is used, and a specific flowchart of the method for determining parameters provided in embodiment 3 of the present invention is shown in fig. 4, and the specific process is as follows:

s101: determining the conduction time of the alternating current fast switching device according to the trigger delay time of the thyristors in the third thyristor module and the fourth thyristor module;

s102: determining the turn-off time of the alternating current rapid switching device according to the turn-off time of the first stage and the turn-off time of the second stage;

the first-stage turn-off time is determined according to the inductance value of the first inductance module and the capacitance value of the capacitor in the forced transfer branch circuit, and the second-stage turn-off time is determined according to the inductance value of the second inductance module and the capacitance value of the capacitor in the forced transfer branch circuit.

The on-time of the ac fast switching device is calculated as follows:

T_on＝T_delay (1)

wherein, T_onIndicating the on-time, T, of the AC fast switching device_delayThe delay time for the triggering of the thyristor (i.e. the time it takes for the thyristor to conduct from the receipt of the trigger signal).

The specific process for determining the turn-off time of the alternating-current fast switching device according to the turn-off time of the first stage and the turn-off time of the second stage is as follows:

the turn-off time of the ac fast switching device is calculated as follows:

T_off＝T_off1+T_off2 (2)

wherein, T_offRepresents the turn-off time of the AC fast switching device, and T_off≤T_{off_max}，T_{off_max}Represents the maximum turn-off time, T, of the AC quick-switching device that the AC system can withstand_off1Denotes the first stage off time, T_off2Indicating a second stage off time.

An equivalent topology of the ac fast switching device in the first stage is shown in fig. 5, where C denotes the capacitance in the forced transfer branch; r₂₁Denotes a first resistance module, R₂₂Representing a second resistance module; r_{on_eq21}The equivalent on-resistance of the thyristors and the diodes when the thyristors in the first thyristor module and the diodes in the first diode module are both on is shown, that is, when all the thyristors in the first thyristor module and all the diodes in the first diode module are both on, the on-resistance of all the thyristors in the first thyristor module and the on-resistance of all the diodes in the first diode module are both onSumming; r_{on_eq22}The equivalent on-resistance of the thyristors and the diodes when the thyristors in the second thyristor module and the diodes in the second diode module are both conducted is represented, namely, the sum of the on-resistance of all the thyristors in the second thyristor module and the on-resistance of all the diodes in the second diode module is obtained when all the thyristors in the second thyristor module and all the diodes in the second diode module are both conducted; l is₂₁Denotes a first inductive module, L₂₂A second inductive module is represented.

1) T mentioned above_off1Calculated as follows:

where ω' represents the angular frequency of oscillation of the first stage, calculated as:

wherein C represents the capacitance value of the capacitor in the forced transfer branch, L₁And R₁Are all intermediate in quantity, and

l mentioned above₁Calculated as follows:

L₁＝(L₂₁+L₂₂)/2 (5)

wherein L is₂₁Representing the inductance, L, of the first inductor module₂₂Representing an inductance value of the second inductance module;

r mentioned above₁Calculated as follows:

R₁＝(R₂₁+R_{on_eq21}+R₂₂+R_{on_eq22})/2 (6)

wherein R is₂₁Representing the resistance, R, of the first resistor module₂₂Representing the resistance, R, of the second resistor module_{on_eq21}Indicating thyristors in the first thyristor module and in the first diode moduleWhen the diodes are all conducted, the sum of the conduction resistances of the thyristor and the diode, R_{on_eq22}Representing the sum of the on-resistances of the thyristor and the diode when both the thyristor in the second thyristor module and the diode in the second diode module are on.

According to fig. 5 and KVL, there are:

wherein u is_C(t) represents the voltage across the capacitor C in the forced transfer branch at time t, and i (t) represents the current passing through the device at time t;

equation (7) can be rewritten as:

the characteristic equation of equation (8) is:

L₁Cp²+R₁Cp+1＝0 (9)

the characteristic root of the above characteristic equation is:

due to the fact that

Then there are:

wherein δ' represents an attenuation coefficient, and

beta' represents an initial phase, and

according to equation (11), the maximum transient current that the first stage device needs to endure is:

wherein i_maxMaximum transient current that the first stage device needs to withstand, and i_max≤I_max，I_maxRepresenting the maximum cis current that the ac fast switching device can withstand.

The equivalent topology of the ac fast switching device in the second stage is shown in fig. 6, where C represents the capacitance in the forced transfer branch; representing the sum of the on-resistances of the thyristor and the diode when both the thyristor in the first thyristor module and the diode in the first diode module are on, or representing the sum of the on-resistances of the thyristor and the diode when both the thyristor in the second thyristor module and the diode in the second diode module are on, i.e. R_{on_eq}Is equal to R_{on_eq1}Or R_{on_eq2}；R_SThe equivalent resistance of an alternating current system connected with the alternating current quick switching device is represented; l is_sThe equivalent inductance of an alternating current system connected with the alternating current fast switching device is represented; l is₂₁Representing the inductance, R, of the first inductor module₂₁Represents the resistance value, L, of the first resistor module₂₁Representing an inductance value of the first inductance module; r in FIG. 1₂₁Can be replaced by R₂₂，R₂₂Representing an inductance value of the second inductance module; l is₂₁Can be replaced by L₂₂，L₂₂Representing the inductance value of the second inductance module.

2) T mentioned above_off2Calculated as follows:

where ω "represents the oscillation angular frequency of the second stage, calculated as:

wherein C represents the capacitance value of the capacitor in the forced transfer branch, L₂And R₂Are all intermediate in quantity, and

l mentioned above₂Calculated as follows:

L₂＝L_eq+L_s (15)

wherein L is_eqIs an intermediate amount, L_eqIs equal to L₂₁Or L₂₂，L_sThe equivalent inductance of an alternating current system connected with the alternating current fast switching device is represented;

r mentioned above₂Calculated as follows:

R₂＝R_S+R_{on_eq} (16)

wherein R is_SRepresenting the equivalent resistance, R, of an AC system to which the AC fast switching device is connected_{on_eq}Is an intermediate amount, R_{on_eq}Is equal to R_{on_eq21}Or R_{on_eq22}。

The method for determining parameters provided in embodiment 3 of the present invention further includes determining L of the following formula₂₁And L₂₂The value range of (A):

wherein, I_maxIndicating the maximum cis-state current, U, that the AC fast switching device can withstand₀Representing the DC voltage supplied to the capacitor by the supply and bleed branches, a and b being intermediate quantities, an

C₀Representing the lower limit of the capacitance value of the capacitor in the forced transfer branch.

Based on the same inventive concept, embodiment 3 of the present invention further provides a parameter determination apparatus for an ac fast switching apparatus based on a thyristor, where the principle of solving the problems of these apparatuses is similar to the parameter determination method for an ac fast switching apparatus based on a thyristor, and the parameter determination apparatus for an ac fast switching apparatus based on a thyristor provided in embodiment 3 of the present invention may include a first determination module, where the first determination module is configured to determine the on-time of the ac fast switching apparatus according to the trigger delay time of the thyristors in the third thyristor module and the fourth thyristor module, and determine the off-time of the ac fast switching apparatus according to the first-stage off-time and the second-stage off-time;

the first-stage turn-off time is determined according to the inductance value of the first inductance module and the capacitance value of the capacitor in the forced transfer branch circuit;

and the turn-off time of the second stage is determined according to the inductance value of the second inductance module and the capacitance value of the capacitor in the forced transfer branch circuit.

The first determining module includes a first determining unit, and the first determining unit calculates the on-time of the ac fast switching device according to the following formula:

T_on＝T_delay

wherein, T_onIndicating the on-time, T, of the AC fast switching device_delayIs the trigger delay time of the thyristor.

The first determining module includes a second determining unit, and the second determining unit calculates the turn-off time of the ac fast switching device according to the following formula:

T_off＝T_off1+T_off2

wherein, T_offRepresents the turn-off time of the AC fast switching device, and T_off≤T_{off_max}，T_{off_max}Represents the maximum turn-off time, T, of the AC quick-switching device that the AC system can withstand_off1Denotes the first stage off time, T_off2Indicating a second stage off time.

The second determining unit calculates T as follows_off1：

Where ω' represents the angular frequency of oscillation of the first stage, calculated as:

wherein C represents the capacitance value of the capacitor in the forced transfer branch, L₁And R₁Are all intermediate in quantity, and

L₁calculated as follows:

L₁＝(L₂₁+L₂₂)/2

wherein L is₂₁Representing the inductance, L, of the first inductor module₂₂Representing an inductance value of the second inductance module;

R₁calculated as follows:

R₁＝(R₂₁+R_{on_eq21}+R₂₂+R_{on_eq22})/2

wherein R is₂₁Representing the resistance, R, of the first resistor module₂₂Representing the resistance, R, of the second resistor module_{on_eq21}Represents the sum of the on-resistances of the thyristor and the diode when both the thyristor in the first thyristor module and the diode in the first diode module are on, R_{on_eq22}Representing the sum of the on-resistances of the thyristor and the diode when both the thyristor in the second thyristor module and the diode in the second diode module are on.

The second determining unit calculates T as follows_off2：

Where ω "represents the oscillation angular frequency of the second stage, calculated as:

wherein C represents the capacitance value of the capacitor in the forced transfer branch, L₂And R₂Are all intermediate in quantity, and

L₂calculated as follows:

L₂＝L_eq+L_s

wherein L is_eqIs an intermediate amount, L_eqIs equal to L₂₁Or L₂₂，L_sThe equivalent inductance of an alternating current system connected with the alternating current fast switching device is represented;

R₂calculated as follows:

R₂＝R_S+R_{on_eq}

wherein R is_SRepresenting the equivalent resistance, R, of an AC system to which the AC fast switching device is connected_{on_eq}Is an intermediate amount, R_{on_eq}Is equal to R_{on_eq21}Or R_{on_eq22}。

The parameter determining device for the thyristor-based alternating-current fast switching device provided by the embodiment 3 of the invention further comprises a second determining module, and the second determining module is used for determining the following formula L₂₁And L₂₂The value range of (A):

wherein, I_maxIndicating the maximum cis-state current, U, that the AC fast switching device can withstand₀Representing the DC voltage supplied to the capacitor by the supply and bleed branches, a and b being intermediate quantities, an

Wherein C is₀Representing the lower limit of the capacitance value of the capacitor in the forced transfer branch.

For convenience of description, each part of the above-described apparatus is separately described as being functionally divided into various modules or units. Of course, the functionality of the various modules or units may be implemented in the same one or more pieces of software or hardware when implementing the present application.

As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

Finally, it should be noted that: the above embodiments are only intended to illustrate the technical solution of the present invention and not to limit the same, and a person of ordinary skill in the art can make modifications or equivalents to the specific embodiments of the present invention with reference to the above embodiments, and such modifications or equivalents without departing from the spirit and scope of the present invention are within the scope of the claims of the present invention as set forth in the claims.

Claims (17)

1. A method for determining parameters of an alternating current fast switching device based on a thyristor is characterized in that the alternating current fast switching device comprises the following steps:

the bidirectional conduction branch is used for realizing bidirectional conduction of working current of the alternating current line;

the forced transfer branch circuit is used for transferring the current of the alternating current circuit in the bidirectional conduction branch circuit to the forced transfer branch circuit and reducing the current of the alternating current circuit transferred to the forced transfer branch circuit to a zero point;

the power supply and discharge branch circuit is used for supplying power to the capacitor in the forced transfer branch circuit and realizing the discharge of the current of the alternating current circuit;

the parameter determination method comprises the following steps:

determining the on-time of the alternating current fast switching device according to the trigger delay time of thyristors in a third thyristor module and a fourth thyristor module in the bidirectional conducting branch, and determining the off-time of the alternating current fast switching device according to the first-stage off-time and the second-stage off-time;

the first-stage turn-off time is determined according to the inductance value of the first inductance module in the forced transfer branch and the capacitance value of the capacitor;

and the turn-off time of the second stage is determined according to the inductance value of the second inductance module in the forced transfer branch circuit and the capacitance value of the capacitor.

2. The thyristor-based ac fast switching device parameter determination method of claim 1, wherein the forced transfer branch comprises a capacitor, a first transfer module, and a second transfer module;

the first transfer module comprises a first thyristor module, a first resistance module and a first inductance module which are connected in series;

the second transfer module comprises a second thyristor module, a second resistor module and a second inductor module which are connected in series;

the first thyristor module and the second thyristor module respectively comprise a plurality of thyristors which are connected in series, parallel or combination of series and parallel;

the cathodes of the thyristors in the first thyristor module face to the node N1, and the anodes face to the second transfer module;

the cathodes of the thyristors in the second thyristor module are all facing node N2, and the anodes are facing the first transfer module.

3. The thyristor-based ac fast switching device parameter determination method of claim 2, wherein the supply and bleed branch is connected in parallel with a capacitor in a forced transfer branch, which comprises a third resistance module, a third inductance module, a full bridge module, and a supply power source;

the full-bridge module comprises a first bridge arm module and a second bridge arm module which are connected in series, and a third bridge arm module and a fourth bridge arm module which are connected in series;

the third resistance module and the third inductance module are connected in series;

the first resistance module, the second resistance module and the third resistance module respectively comprise a plurality of resistances which are connected in series, in parallel or in combination of series and parallel;

the first inductor module, the second inductor module and the third inductor module respectively comprise a plurality of inductors, and the plurality of inductors are connected in series, in parallel or in combination of series and parallel.

4. A thyristor-based ac fast switching device parameter determination method according to claim 3, wherein the first leg module and the second leg module each comprise a plurality of diodes in series, parallel, or a combination thereof;

the third bridge arm module and the fourth bridge arm module respectively comprise a plurality of thyristors which are connected in series, in parallel or in series-parallel;

cathodes of all diodes in the first bridge arm module are connected with a common point G between the first bridge arm module and the second bridge arm module, and anodes of all diodes are connected with a common point A between the first bridge arm module and the third bridge arm module;

cathodes of all diodes in the second bridge arm module are connected with a common point K between the second bridge arm module and the fourth bridge arm module, and anodes of all diodes are connected with a common point A between the first bridge arm module and the second bridge arm module;

cathodes of all thyristors in the third bridge arm module are connected with a common point Y between the third bridge arm module and the fourth bridge arm module, and anodes of all thyristors are connected with a common point G between the first bridge arm module and the third bridge arm module;

cathodes of all thyristors in the fourth bridge arm module are connected with a common point Y between the second bridge arm module and the fourth bridge arm module, and anodes of all thyristors are connected with a common point K between the third bridge arm module and the fourth bridge arm module.

5. The thyristor-based AC fast switching device parameter determination method of claim 4, wherein the bidirectional conduction branch comprises a first bidirectional conduction module and a second bidirectional conduction module connected in series;

the first bidirectional switch-on module comprises a first diode module and a third thyristor module which are connected in parallel;

the second bidirectional conducting module comprises a second diode module and a fourth thyristor module which are connected in parallel;

the first diode module and the second diode module respectively comprise a plurality of diodes, and the plurality of diodes are connected in series, in parallel or in combination of series and parallel;

the third thyristor module and the fourth thyristor module both comprise a plurality of thyristors which are connected in series, parallel or combination of series and parallel;

the anodes of the diodes in the first diode module face to the node N1, and the cathodes of the diodes face to the second bidirectional conduction module;

the cathodes of the thyristors in the third thyristor module face to the node N1, and the anodes of the thyristors in the third thyristor module face to the second bidirectional conduction module;

the anodes of the diodes in the second diode module face to the node N2, and the cathodes of the diodes face to the first bidirectional conduction module;

the cathodes of the thyristors in the fourth thyristor module are all facing the node N2, and the anodes thereof are all facing the first bidirectional conducting module.

6. A thyristor-based AC fast switching device parameter determination method according to claim 5, wherein the common point A is connected to a common point J between the first and second bidirectional conduction modules through a third resistance module and a third inductance module connected in series, and the common point Y is connected to a common point F between the first and second current limiting modules;

one end of the capacitor is connected with the common point J, and the other end of the capacitor is connected with the common point F;

and one end of the power supply is connected with the common point K, and the other end of the power supply is connected with the common point G.

7. A thyristor-based AC fast switching device parameter determination method according to any one of claims 1 to 6, wherein the conduction time of the AC fast switching device is calculated as follows:

T_on＝T_delay

wherein, T_onAC quick indicating switchOn-time of the device, T_delayIs the trigger delay time of the thyristor.

8. The thyristor-based AC fast switching device parameter determination method of claim 6, wherein determining the turn-off time of the AC fast switching device as a function of the first-stage turn-off time and the second-stage turn-off time comprises:

the turn-off time of the ac fast switching device is calculated as follows:

T_off＝T_off1+T_off2

wherein, T_offRepresents the turn-off time of the AC fast switching device, and T_off≤T_{off_max}，T_{off_max}Represents the maximum turn-off time, T, of the AC quick-switching device that the AC system can withstand_off1Denotes the first stage off time, T_off2Indicating a second stage off time.

9. The method of claim 8 wherein T is calculated as follows_off1：

Where ω' represents the angular frequency of oscillation of the first stage, calculated as:

wherein C represents the capacitance value of the capacitor in the forced transfer branch, L₁And R₁Are all intermediate in quantity, and

L₁calculated as follows:

L₁＝(L₂₁+L₂₂)/2

wherein L is₂₁Representing the inductance, L, of the first inductor module₂₂Representing an inductance value of the second inductance module;

R₁calculated as follows:

R₁＝(R₂₁+R_{on_eq21}+R₂₂+R_{on_eq22})/2

wherein R is₂₁Representing the resistance, R, of the first resistor module₂₂Representing the resistance, R, of the second resistor module_{on_eq21}Represents the sum of the on-resistances of the thyristor and the diode when both the thyristor in the first thyristor module and the diode in the first diode module are on, R_{on_eq22}Representing the sum of the on-resistances of the thyristor and the diode when both the thyristor in the second thyristor module and the diode in the second diode module are on.

10. The method of claim 9 wherein T is calculated as follows_off2：

Where ω "represents the oscillation angular frequency of the second stage, calculated as:

wherein C represents the capacitance value of the capacitor in the forced transfer branch, L₂And R₂Are all intermediate in quantity, and

L₂calculated as follows:

L₂＝L_eq+L_s

wherein L is_eqIs an intermediate amount, L_eqIs equal to L₂₁Or L₂₂，L_sThe equivalent inductance of an alternating current system connected with the alternating current fast switching device is represented;

R₂calculated as follows:

R₂＝R_S+R_{on_eq}

wherein R is_SRepresenting the equivalent resistance, R, of an AC system to which the AC fast switching device is connected_{on_eq}Is an intermediate amount, R_{on_eq}Is equal to R_{on_eq21}Or R_{on_eq22}。

11. The thyristor-based ac fast switching device parameter determination method of claim 10, further comprising determining L as₂₁And L₂₂The value range of (A):

wherein, I_maxIndicating the maximum cis-state current, U, that the AC fast switching device can withstand₀Representing the DC voltage supplied to the capacitor by the supply and bleed branches, a and b being intermediate quantities, an

C₀Representing the lower limit of the capacitance value of the capacitor in the forced transfer branch.

12. A thyristor-based parameter determination device for an AC fast switching device, comprising:

the first determining module is used for determining the turn-on time of the alternating current fast switching device according to the trigger delay time of the thyristors in the third thyristor module and the fourth thyristor module and determining the turn-off time of the alternating current fast switching device according to the turn-off time of the first stage and the turn-off time of the second stage;

the first-stage turn-off time is determined according to the inductance value of the first inductance module and the capacitance value of the capacitor in the forced transfer branch circuit;

the second-stage turn-off time is determined according to the inductance value of the second inductance module and the capacitance value of the capacitor in the forced transfer branch circuit;

the forced transfer branch comprises a capacitor, a first transfer module and a second transfer module;

the first transfer module comprises a first thyristor module, a first resistance module and a first inductance module which are connected in series;

the second transfer module comprises a second thyristor module, a second resistor module and a second inductor module which are connected in series;

the first thyristor module and the second thyristor module respectively comprise a plurality of thyristors which are connected in series, parallel or combination of series and parallel;

the cathodes of the thyristors in the first thyristor module face to the node N1, and the anodes face to the second transfer module;

the cathodes of the thyristors in the second thyristor module face to the node N2, and the anodes face to the first transfer module;

the third thyristor module belongs to a first bidirectional conduction module, the fourth thyristor module belongs to a second bidirectional conduction module, and the first bidirectional conduction module and the second bidirectional conduction module are connected in series to form a bidirectional conduction branch;

the first bidirectional switch-on module also comprises a first diode module which is connected with the third thyristor module in parallel;

the second bidirectional conduction module further comprises a second diode module, and the second diode module is connected with the fourth thyristor module in parallel;

the first diode module and the second diode module respectively comprise a plurality of diodes, and the plurality of diodes are connected in series, in parallel or in combination of series and parallel;

the third thyristor module and the fourth thyristor module both comprise a plurality of thyristors which are connected in series, parallel or combination of series and parallel;

the anodes of the diodes in the first diode module face to the node N1, and the cathodes of the diodes face to the second bidirectional conduction module;

the cathodes of the thyristors in the third thyristor module face to the node N1, and the anodes of the thyristors in the third thyristor module face to the second bidirectional conduction module;

the anodes of the diodes in the second diode module face to the node N2, and the cathodes of the diodes face to the first bidirectional conduction module;

the cathodes of the thyristors in the fourth thyristor module are all facing the node N2, and the anodes thereof are all facing the first bidirectional conducting module.

13. The thyristor-based ac fast switching device parameter determination apparatus of claim 12, wherein the first determination module comprises a first determination unit that calculates the on-time of the ac fast switching device according to the following equation:

T_on＝T_delay

wherein, T_onIndicating the on-time, T, of the AC fast switching device_delayIs the trigger delay time of the thyristor.

14. The thyristor-based ac fast switching device parameter determination apparatus of claim 13, wherein the first determination module comprises a second determination unit that calculates the off-time of the ac fast switching device according to the following equation:

T_off＝T_off1+T_off2

wherein, T_offRepresents the turn-off time of the AC fast switching device, and T_off≤T_{off_max}，T_{off_max}Represents the maximum turn-off time, T, of the AC quick-switching device that the AC system can withstand_off1Denotes the first stage off time, T_off2Indicating the second stage offAnd (7) off-time.

15. The thyristor-based ac fast switching device parameter determination apparatus as claimed in claim 14, wherein the second determination unit is specifically configured to:

t is calculated as follows_off1：

Where ω' represents the angular frequency of oscillation of the first stage, calculated as:

wherein C represents the capacitance value of the capacitor in the forced transfer branch, L₁And R₁Are all intermediate in quantity, and

L₁calculated as follows:

L₁＝(L₂₁+L₂₂)/2

wherein L is₂₁Representing the inductance, L, of the first inductor module₂₂Representing an inductance value of the second inductance module;

R₁calculated as follows:

R₁＝(R₂₁+R_{on_eq21}+R₂₂+R_{on_eq22})/2

wherein R is₂₁Representing the resistance, R, of the first resistor module₂₂Representing the resistance, R, of the second resistor module_{on_eq21}Represents the sum of the on-resistances of the thyristor and the diode when both the thyristor in the first thyristor module and the diode in the first diode module are on, R_{on_eq22}Indicating the on-resistance of the thyristor and diode when both the thyristor in the second thyristor module and the diode in the second diode module are onAnd (4) summing.

16. The thyristor-based ac fast switching device parameter determination apparatus of claim 15, wherein the second determination unit is specifically configured to:

t is calculated as follows_off2：

Where ω "represents the oscillation angular frequency of the second stage, calculated as:

wherein C represents the capacitance value of the capacitor in the forced transfer branch, L₂And R₂Are all intermediate in quantity, and

L₂calculated as follows:

L₂＝L_eq+L_s

wherein L is_eqIs an intermediate amount, L_eqIs equal to L₂₁Or L₂₂，L_sThe equivalent inductance of an alternating current system connected with the alternating current fast switching device is represented;

R₂calculated as follows:

R₂＝R_S+R_{on_eq}

wherein R is_SRepresenting the equivalent resistance, R, of an AC system to which the AC fast switching device is connected_{on_eq}Is an intermediate amount, R_{on_eq}Is equal to R_{on_eq21}Or R_{on_eq22}。

17. A thyristor-based ac fast switching device parameter determination apparatus as claimed in claim 16, whereinThe parameter determination apparatus further comprises a second determination module for determining L of the formula₂₁And L₂₂The value range of (A):

wherein, I_maxIndicating the maximum cis-state current, U, that the AC fast switching device can withstand₀Representing the DC voltage supplied to the capacitor by the supply and bleed branches, a and b being intermediate quantities, an

Wherein C is₀Representing the lower limit of the capacitance value of the capacitor in the forced transfer branch.

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