CN117810903A - Silicon controlled rectifier active turn-off device and control method - Google Patents
Silicon controlled rectifier active turn-off device and control method Download PDFInfo
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- CN117810903A CN117810903A CN202410234246.9A CN202410234246A CN117810903A CN 117810903 A CN117810903 A CN 117810903A CN 202410234246 A CN202410234246 A CN 202410234246A CN 117810903 A CN117810903 A CN 117810903A
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- voltage
- silicon controlled
- controlled rectifier
- power grid
- current
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- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 title claims abstract description 71
- 229910052710 silicon Inorganic materials 0.000 title claims abstract description 71
- 239000010703 silicon Substances 0.000 title claims abstract description 71
- 238000000034 method Methods 0.000 title claims abstract description 19
- 230000002457 bidirectional effect Effects 0.000 claims abstract description 41
- 238000004146 energy storage Methods 0.000 claims abstract description 13
- 230000001105 regulatory effect Effects 0.000 claims abstract description 6
- 230000002159 abnormal effect Effects 0.000 claims description 4
- 230000001052 transient effect Effects 0.000 claims description 4
- 230000001276 controlling effect Effects 0.000 claims description 3
- HJELPJZFDFLHEY-UHFFFAOYSA-N silicide(1-) Chemical compound [Si-] HJELPJZFDFLHEY-UHFFFAOYSA-N 0.000 claims 4
- 238000010586 diagram Methods 0.000 description 6
- 230000000694 effects Effects 0.000 description 5
- 238000004088 simulation Methods 0.000 description 4
- 238000010587 phase diagram Methods 0.000 description 2
- 230000000630 rising effect Effects 0.000 description 2
- 230000001629 suppression Effects 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
Classifications
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/02—Details
- H02H3/021—Details concerning the disconnection itself, e.g. at a particular instant, particularly at zero value of current, disconnection in a predetermined order
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/26—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/12—Circuit arrangements for ac mains or ac distribution networks for adjusting voltage in ac networks by changing a characteristic of the network load
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
- H03K17/51—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used
- H03K17/56—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices
- H03K17/72—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices having more than two PN junctions; having more than three electrodes; having more than one electrode connected to the same conductivity region
- H03K17/725—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices having more than two PN junctions; having more than three electrodes; having more than one electrode connected to the same conductivity region for ac voltages or currents
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Rectifiers (AREA)
Abstract
The invention aims to provide a thyristor active turn-off device and a control method, which have low cost, solve the problem of thyristor rapid turn-off when the voltage of the power grid side is temporarily increased in the rapid voltage regulating device AVC, and improve the overcurrent problem caused by phase jump of the power grid side short circuit fault. The invention comprises a silicon controlled rectifier, a bidirectional converter, an energy storage direct current source and a bypass switch; the wire inlet end of the controllable silicon is connected with a power grid, and the wire outlet end of the controllable silicon is connected with a load; the energy storage direct current source and the bidirectional converter are connected in parallel between the controllable silicon and the load; the parallel end is positioned at the load side of the silicon controlled rectifier; the energy storage direct current source is connected with the bidirectional converter; and the incoming line end of the bypass switch is connected with the power grid, and the outgoing line end of the bypass switch is connected with the load. The invention is applied to the application of active shutdown.
Description
Technical Field
The invention relates to the technical field of active turn-off, in particular to a silicon controlled active turn-off device and a control method.
Background
A fast voltage regulator device incorporating a SCR is shown in fig. 7. AVC can provide power to sensitive loads when the grid fluctuates for a short time. When the power grid normally operates, the silicon controlled rectifier is conducted, and the load is powered by the power grid; when the power grid is abnormal, the controllable silicon cuts off the load from the power grid fault, and the load is supplied with power by the bidirectional converter. The faster the SCR turn-off speed of the AVC equipment is, the better the power supply guarantee effect on the load is, and the load is prevented from being influenced by grid faults and overcurrent. The turn-on of the thyristor can be controlled by the driving signal, but the turn-off action is not completely controlled by the signal, and the turn-off condition is as follows: after the drive signal is stopped being sent, the voltage at the two ends of the controllable silicon is reversed or the current passing through the controllable silicon is smaller than the maintaining current, and the controllable silicon can be turned off.
At present, when AVC processes the situations of voltage sag/rise and the like, the active turn-off mode of the SCR is as follows: the voltage output of the PCS shown in fig. 8 is controlled so that the voltage of the PCS terminal of the silicon controlled rectifier in AVC is higher than the voltage of the network side, and the purpose of rapidly switching off the electronic switch SCR is achieved through the zero crossing of the current of the SCR.
The output control method of the PCS in this method is a voltage source mode, as shown in fig. 9. The reference signal for the control is set output voltage, and PWM signals are calculated through the voltage outer loop and current inner loop controller to drive the power module of the PCS inverter. The setting of the reference voltage is adjusted according to the actual network side voltage.
If the voltage sag fault occurs in the power grid, the PCS is required to output higher voltage to provide the reverse voltage of the SCR, and the thyristor is turned off rapidly. On one hand, the PCS outputs a voltage value higher than the power grid temporary rising voltage, the tolerance range of a load is considered, and enough output electric energy is provided to turn off the silicon controlled rectifier, so that the voltage reference value range is narrow and is not easy to control; on the other hand, the output of the PCS needs to be continuously adjusted in real time according to the temporary rising voltage to realize the turn-off, and when the voltage of the power grid is temporarily raised, the voltage of the PCS is clamped by the power grid and the conducted SCR, the feedback voltage of the PCS in the actual control process is not easy to sample and judge, and the control of the voltage source is not easy to realize. It can be seen that voltage sag uses voltage source type control to not easily turn off the SCR and there is a risk of load overvoltage.
Fig. 10 shows an overcurrent phase simulation caused by the voltage source type PCS output voltage if it is not higher than the grid-dip voltage. In the simulation, the power grid voltage is temporarily increased to 230.9V, the output of the PCS is low, the silicon controlled rectifier cannot be turned off, and the power grid energy is filled into the PCS through the SCR.
When short-circuit faults (single-phase, two-phase short-circuit, two-phase, three-phase grounding and the like) occur at the power grid side, the PCS can follow the phase of the power grid in normal state, and due to impedance in the power transmission line, phase jump of the power grid faults can occur, so that deviation of the output phase of the PCS and the voltage phase of the power grid is caused. Different short-circuit phases may cause PCS to over-current, and the thyristor takes longer to naturally turn off.
Fig. 11 shows a fault waveform simulation at BC two-phase ground shorts. The short circuit occurs at phase 75 of phase a, as shown in the figure, the network side voltage has a phase jump due to the short circuit, and the SCR has an overcurrent phase.
Therefore, it is necessary to provide a device and a method for controlling the active turn-off of the thyristor, which are low in cost, solve the problem of the rapid turn-off of the thyristor when the voltage of the power grid side is temporarily raised in the AVC, and improve the overcurrent problem caused by phase jump of the short circuit fault of the power grid side.
Disclosure of Invention
The invention aims to solve the technical problems of overcoming the defects of the prior art, and provides a silicon controlled rectifier active shutoff device and a control method which have low cost, solve the problem of rapid shutoff of a silicon controlled rectifier when the voltage of the power grid side is temporarily increased in an AVC (automatic voltage control) device and improve the overcurrent problem caused by phase jump of a short circuit fault of the power grid side.
The technical scheme adopted by the invention is as follows: the invention comprises a silicon controlled rectifier, a bidirectional converter, an energy storage direct current source and a bypass switch; the wire inlet end of the controllable silicon is connected with a power grid, and the wire outlet end of the controllable silicon is connected with a load; the energy storage direct current source and the bidirectional converter are connected in parallel between the controllable silicon and the load; the parallel end is positioned at the load side of the silicon controlled rectifier; the energy storage direct current source is connected with the bidirectional converter; and the incoming line end of the bypass switch is connected with the power grid, and the outgoing line end of the bypass switch is connected with the load.
The scheme can effectively ensure the protection of the quick voltage regulating device and the parallel bidirectional converter to the sensitive load; the problem of the rapid turn-off of the silicon controlled rectifier when the voltage of the power grid side in the rapid voltage regulating device AVC is temporarily increased can be solved; the overcurrent problem caused by phase jump in the power grid side short circuit fault can be solved; the active quick turn-off of the controllable silicon is realized through the existing active components of the bidirectional converter without adding any components, and the cost is effectively controlled.
In one preferred scheme, the silicon controlled rectifier comprises two groups of forward silicon controlled rectifiers and reverse silicon controlled rectifiers which are connected in parallel to provide a bidirectional path for alternating current.
The silicon controlled rectifier active shutoff device comprises a fault judging module, a silicon controlled rectifier driving control module, an adjustment quantity selecting module and a converter output control module;
the control method comprises the following steps:
A. when the power grid has abnormal faults, the fault judging module judges that the power grid has faults, and stops the driving signal faults of the controllable silicon; the fault judging module divides the network side fault into a voltage sag fault and a voltage sag fault;
B. the adjustment quantity selection module selects an adjustment quantity according to the fault type, and when the voltage sag fault occurs, the voltage of the bidirectional converter is selected as the adjustment quantity; when the voltage transient rise fault occurs, selecting the current of the bidirectional converter as an adjustment quantity;
C. when the voltage is used as an adjustment quantity, the output control module of the converter controls the output voltage in a voltage source mode, the output voltage is higher than the network side voltage, and the silicon controlled rectifier is effectively and rapidly turned off; when the current of the silicon controlled rectifier flows in the output process of the voltage source, the current is used as an adjustment quantity to inhibit phase jump possibly caused by network side short circuit; the power grid is recovered to be normal, and the bidirectional converter stops outputting;
D. when the current is used as an adjustment quantity, the output control module of the converter controls the output current in a current source mode to provide output for the load, the current of the silicon controlled rectifier quickly crosses zero, and the silicon controlled rectifier is effectively and quickly turned off; after the silicon controlled rectifier is turned off, voltage is used as an adjustment quantity, and the voltage is used as a voltage source output to cope with the load change during compensation; and the power grid is recovered to be normal, and the bidirectional converter stops outputting.
Drawings
FIG. 1 is a block diagram of the structure of the present invention;
FIG. 2 is a control schematic of the present invention;
figure 3 is a circuit diagram of the bi-directional current transformer;
FIG. 4 is a block diagram of the bi-directional current transformer transient current control;
fig. 5 is a graph of the effect of current source control of the bidirectional converter on controlling the voltage sag at the network side;
fig. 6 is a graph of an overcurrent suppression effect of the bidirectional current transformer current source when the network side is short-circuited;
FIG. 7 is a schematic diagram of a prior art thyristor master circuit of a fast voltage regulator device;
fig. 8 is a main circuit diagram of a prior art bi-directional current transformer;
FIG. 9 is a prior art voltage outer loop current inner loop control block diagram;
fig. 10 is an overcurrent phase diagram when the voltage source control governing network side voltage of the prior art bidirectional converter is temporarily raised;
fig. 11 is a prior art grid-side short circuit, bi-directional converter voltage source control overcurrent phase diagram.
Detailed Description
As shown in fig. 1 to 3, in the present embodiment, the present invention includes a thyristor 1, a bidirectional converter 2, an energy storage dc source 3, and a bypass switch 4; the wire inlet end of the silicon controlled rectifier 1 is connected with a power grid 5, and the wire outlet end of the silicon controlled rectifier 1 is connected with a load 6; the energy storage direct current source 3 and the bidirectional converter 2 are connected in parallel between the controllable silicon 1 and the load 6; the parallel end is positioned at the load side of the silicon controlled rectifier 1; the energy storage direct current source 3 is connected with the bidirectional converter 2; the incoming line end of the bypass switch 4 is connected with the power grid 5, and the outgoing line end of the bypass switch 4 is connected with the load 6.
As shown in fig. 1, in this embodiment, the silicon controlled rectifier 1 includes two groups of parallel forward silicon controlled rectifiers and reverse silicon controlled rectifiers, which provide a bidirectional path for alternating current.
As shown in fig. 2, in this embodiment, the scr active shutdown device further includes a fault judging module 8, a scr driving control module 9, an adjustment amount selecting module 10, and a converter output control module 11;
the control method comprises the following steps:
A. when the power grid 5 has abnormal faults, the fault judging module 8 judges that the power grid 5 has faults, and stops the driving signal faults of the silicon controlled rectifier 1; the fault judging module 8 divides the network side faults into voltage sag faults and voltage rise faults;
B. the adjustment amount selection module 10 selects an adjustment amount according to the fault type, and when the voltage sag fault occurs, the voltage of the bidirectional converter 2 is selected as the adjustment amount; when the voltage transient rise fault occurs, selecting the current of the bidirectional converter 2 as an adjustment quantity;
C. when the voltage is used as an adjustment quantity, the converter output control module 11 controls the output voltage in a voltage source mode, the output voltage is higher than the network side voltage, and the silicon controlled rectifier 1 is effectively and quickly turned off; when the current of the silicon controlled rectifier 1 flows in the output process of the voltage source, the current is used as an adjustment quantity to inhibit phase jump possibly caused by network side short circuit; the power grid 5 is recovered to be normal, and the bidirectional converter 2 stops outputting;
D. when the current is used as an adjustment quantity, the current output control module 11 performs output current control in a current source mode to provide output for the load 6, and the current of the silicon controlled rectifier 1 quickly crosses zero, so that the silicon controlled rectifier 1 is effectively and quickly turned off; after the silicon controlled rectifier 1 is turned off, voltage is used as an adjustment quantity, and the voltage is used as a voltage source output to cope with the change of the load 6 when compensation is performed; the grid 5 returns to normal and the bi-directional converter 2 stops outputting.
According to different conditions of a power grid, the voltage/current is used as an adjustment quantity according to two conditions of the turn-off of the controllable silicon, and the controllable silicon is turned off actively and rapidly while the sensitive load is powered. When the voltage of the power grid is reduced, the voltage source output control of the bidirectional converter is used, and the silicon controlled rectifier is rapidly turned off by high voltage; when the voltage of the power grid is temporarily increased or the bidirectional converter is over-current due to short-circuit fault, the bidirectional converter can be controlled to switch to a current source mode to limit current output, and a higher voltage value is not continuously output according to the temporarily increased power grid voltage. Therefore, the current of the controllable silicon is effectively controlled, and the controllable silicon is turned off in time.
The current source controller is shown in fig. 4, in order to restrain the current of the bidirectional converter, the current loop of the bidirectional converter can adjust the duty ratio output, the actual power output of the bidirectional converter is increased, the effect of clamping the voltage of the load side of the silicon controlled rectifier is achieved, and the current of the silicon controlled rectifier is enabled to cross zero in time. After the controllable silicon is turned off, the current source control mode can be switched back to the voltage source control mode, and the independent inversion voltage output for charge is ensured.
The method not only can effectively turn off the silicon controlled rectifier when the voltage at the network side is temporarily increased, but also can prevent the overcurrent phenomenon caused by phase deviation under different short circuit conditions, so that the AVC can more effectively process different power grid conditions and ensure the normal operation of the load. AVC refers to a fast voltage regulator device that contains a thyristor SCR.
Fig. 5 shows the effect of voltage sag management under current source control. At this time, the voltage at the network side is 239.1V, and the SCR current can be seen to quickly cross zero due to the action of the current source controller.
Fig. 6 shows fault waveform simulation of BC two phases at a phase of 75 ° of phase a in the case of a ground short circuit, and the SCR overcurrent effect was successfully managed due to the suppression effect of the current source control.
In this embodiment, as can be seen from the analysis of fig. 7 to 11, the bidirectional converter refers to PCS, and the PCS outputs energy to charge the battery/supercapacitor of the PCS. Because the impedance between the bidirectional converter and the power grid is generally smaller, the bidirectional converter and the SCR are often directly caused to overcurrent in a voltage source control mode. Since two ideal voltage sources are connected in parallel, a current is formed between the two sources, and the current is determined by the line impedance and the internal resistance; the voltage source and the current source are connected in parallel, and the current is controlled by the current source.
Claims (3)
1. The utility model provides a silicon controlled rectifier active shutoff device which characterized in that: the energy storage direct current power supply comprises a controllable silicon (1), a bidirectional converter (2), an energy storage direct current source (3) and a bypass switch (4); the wire inlet end of the controllable silicon (1) is connected with a power grid (5), and the wire outlet end of the controllable silicon (1) is connected with a load (6); the energy storage direct current source (3) and the bidirectional converter (2) are connected in parallel between the controllable silicon (1) and the load (6); the parallel end is positioned at the load side of the silicon controlled rectifier (1); the energy storage direct current source (3) is connected with the bidirectional converter (2); the incoming line end of the bypass switch (4) is connected with the power grid (5), and the outgoing line end of the bypass switch (4) is connected with the load (6).
2. A thyristor active shutoff device according to claim 1, wherein: the silicon controlled rectifier (1) comprises two groups of forward silicon controlled rectifiers and reverse silicon controlled rectifiers which are connected in parallel, and a bidirectional passage is provided for alternating current.
3. A method of controlling a thyristor active shutoff device of claim 1, wherein: the silicon controlled rectifier active shutoff device also comprises a fault judging module (8), a silicon controlled rectifier driving control module (9), an adjustment quantity selecting module (10) and a converter output control module (11);
the control method comprises the following steps:
A. when the power grid (5) has abnormal faults, the fault judging module (8) judges that the power grid (5) has faults, and stops the driving signal faults of the silicon controlled rectifier (1); the fault judging module (8) divides the network side fault into a voltage sag fault and a voltage rise fault;
B. the regulating quantity selecting module (10) selects regulating quantity according to fault type, and when the voltage sag fault occurs, the voltage of the bidirectional converter (2) is selected as the regulating quantity; when the voltage transient rise fault occurs, selecting the current of the bidirectional converter (2) as an adjustment quantity;
C. when the voltage is used as an adjustment quantity, the converter output control module (11) performs output voltage control in a voltage source mode, the output voltage is higher than the network side voltage, and the silicon controlled rectifier (1) is effectively and rapidly turned off; when the current of the silicon controlled rectifier (1) flows in the output process of the voltage source, the current is used as an adjustment quantity to inhibit phase jump possibly caused by network side short circuit; the power grid (5) is recovered to be normal, and the bidirectional converter (2) stops outputting;
D. when the current is used as an adjustment quantity, the current output control module (11) performs output current control in a current source mode to provide output for the load (6), and the current of the silicon controlled rectifier (1) quickly crosses zero, so that the silicon controlled rectifier (1) is effectively and quickly turned off; after the silicon controlled rectifier (1) is turned off, voltage is used as an adjustment quantity, and the voltage is used as a voltage source output to cope with the change of the load (6) when compensation is performed; and the power grid (5) is restored to be normal, and the bidirectional converter (2) stops outputting.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410234246.9A CN117810903A (en) | 2024-03-01 | 2024-03-01 | Silicon controlled rectifier active turn-off device and control method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410234246.9A CN117810903A (en) | 2024-03-01 | 2024-03-01 | Silicon controlled rectifier active turn-off device and control method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117810903A true CN117810903A (en) | 2024-04-02 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202410234246.9A Pending CN117810903A (en) | 2024-03-01 | 2024-03-01 | Silicon controlled rectifier active turn-off device and control method |
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| Country | Link |
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| CN (1) | CN117810903A (en) |
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2024
- 2024-03-01 CN CN202410234246.9A patent/CN117810903A/en active Pending
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