JP4643225B2 - Instantaneous voltage drop prevention device and instantaneous voltage drop prevention method - Google Patents

Description

  The present invention relates to an instantaneous voltage drop prevention device and an instantaneous voltage drop prevention method for preventing a temporary voltage drop that occurs when a fault section is removed in a power system.

  In a power system, when lightning falls on a transmission tower or the like, a large fault current flows through the transmission line. In the power transmission / transformation equipment, the failure current is detected and the failure section is separated to prevent a power failure. However, a very short time (0.07 to 0.2) from the occurrence of this lightning strike to the separation of the failure section. (Seconds) System voltage temporarily drops.

Such a voltage drop is referred to as an instantaneous voltage drop (instantaneous drop).
Although the instantaneous voltage drop is a very short time until the failure is removed, it is a problem because it has an adverse effect on voltage sensitive devices such as computers and power receiving facilities of electric power consumers.

  Conventionally, a tap-type voltage regulator (TVR = Thyristor Voltage Regulator) using a thyristor switch has already been put into practical use as a voltage regulator between a power source and a load in a power transmission / distribution network provided between a power source and a load. It has become.

  Thyristors are the cheapest switching elements using power semiconductors, and tap voltage regulators using this thyristor are the step voltage regulators that are widely installed in power distribution systems. This is much faster than the switching time (about 2.5 cycles at the earliest) of the device (SVR = Step Voltage Regulator).

  The conventional tap type voltage regulator circuit is shown in FIG. 14 includes a U-phase terminal 201, a V-phase terminal 202, and a W-phase terminal 203 on the primary side of a three-phase circuit whose phase sequence is UVW, and a U-phase terminal 301 on the secondary side. A V-phase terminal 302 and a W-phase terminal 303 are provided.

A series transformer 101 is connected in series to each line of the three-phase circuit, and a regulating transformer 102 that supplies a voltage to be applied to the series transformer 101 is provided on the load side.
Between the primary winding 101a of the series transformer 101 and the secondary winding 102b of the adjustment transformer 102, a tap configured by bridge-connecting thyristor switches S1 to S6 in which two thyristors are connected in antiparallel. A switching circuit 103 is connected.

In such a tap type voltage regulator using a thyristor switch, the voltage of the power system is detected by a voltage detector (not shown), and based on the detection signal from the voltage detector, the thyristor switch is changed according to the change of the system voltage. S1 to S6 are switched, and the tap position of the adjustment transformer 102 is changed step by step in increments of 1 to maintain the secondary side voltage of the series transformer 101 at a predetermined voltage. (For example, refer to Patent Document 1 and Non-Patent Document 1.)
JP 11-312612 A (P2) ICEE 2001 Proceedings p1076 (Development and Application of New Voltage Regulator with Thyristor Based Tap Changer for Improving Power Quality)

In recent years, there has been a problem that the instantaneous voltage drop phenomenon in the power system adversely affects various loads. However, the tap voltage regulator can be used as a device that prevents the instantaneous voltage drop. It is slow and cannot be applied as an instantaneous voltage drop prevention device.
For this reason, an instantaneous voltage drop prevention device that can further prevent various adverse effects on the load due to the instantaneous voltage drop phenomenon is desired.

  The present invention has been made to solve the above-mentioned problems, and its purpose is to use a tap switching method using a thyristor switch, further shortening the tap switching time, and various adverse effects on the load due to the instantaneous voltage drop phenomenon of the power supply. It is an object of the present invention to provide an instantaneous voltage drop prevention device and an instantaneous voltage drop prevention method capable of preventing the above.

  In order to achieve the above object, the invention of the instantaneous voltage drop prevention device of the present invention comprises a series transformer connected in series to a line, a primary winding and a secondary winding provided with taps, A primary winding is connected to the load side of the secondary winding of the series transformer, and a plurality of adjustment transformers for applying a voltage to the primary winding of the series transformer and a pair of thyristors connected in reverse parallel It consists of a thyristor switch that is bridge-connected and consists of a thyristor tap switching circuit that is connected between the secondary winding of the regulating transformer and the primary winding of the series transformer. Accordingly, the conduction state of the thyristor switch of the thyristor tap switching circuit is switched, and the tap of the primary winding of the adjustment transformer is switched in the direction of increasing the voltage.

  In addition, the invention of the instantaneous voltage drop prevention method of the present invention comprises voltage transformation means that is connected in series to the line and transforms the voltage of the line, a primary winding and a secondary winding provided with taps, A primary winding is connected to the load side of the secondary winding of the voltage transformation means, and a plurality of voltage adjustment means for applying a voltage to the primary winding of the voltage transformation means and a pair of thyristors connected in reverse parallel A thyristor switch is bridge-connected, and is connected between the secondary winding of the voltage adjusting means and the primary winding of the voltage transforming means, and has a means for switching taps, according to the amount of voltage decrease on the power supply side The thyristor switch is switched on in accordance with a table prepared in advance, and the tap of the primary winding of the voltage adjusting means is switched in the direction of increasing the voltage.

  According to the instantaneous voltage drop prevention device and the instantaneous voltage drop prevention method of the present invention, the tap switching method using a thyristor switch is used, and the tap switching time is short, thereby preventing various adverse effects on the load due to the instantaneous voltage drop phenomenon of the power source. be able to.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 and 2 are views showing an instantaneous voltage drop prevention device according to a first embodiment of the present invention.
In FIG. 1, reference numeral 1 denotes an instantaneous voltage drop prevention device according to the present embodiment, a primary side terminal including a U-phase terminal 1U, a V-phase terminal 1V, and a W-phase terminal 1W connected to the power supply side of the power system; A secondary-side terminal including a U-phase terminal 2U, a V-phase terminal 2V, and a W-phase terminal 2W connected to the load side of the power system is provided, and the power supply and load of the power system three-phase circuit whose phase sequence is UVW They are connected in series.

Series transformers 31, 32, and 33 are connected in series to each line connecting the power source and the load of the power system three-phase circuit.
The load side of the secondary windings 31b, 32b, 33b of the series transformers 31, 32, 33 is connected in parallel between the lines, and is connected to the primary windings 31a, 32a, 33a of the series transformers 31, 32, 33. It is connected to the tapped primary windings 41a, 42a of the adjustment transformers 41, 42 to which the voltage is applied.

  Further, the tapped secondary windings 41b, 42b of the adjustment transformers 41, 42 are connected to the primary windings 31a, 32a, 33a of the series transformers 31, 32, 33 via the thyristor tap switching circuits 51, 52. ing.

  FIG. 2 is a diagram showing the electrical configuration of the thyristor tap switching circuits 51 and 52 of the instantaneous voltage drop prevention device capable of compensating for the instantaneous voltage drop when the voltage on the power source side is about 0 to 48% of the rated voltage, for example. It is.

  In FIG. 2, reference numerals 51a to 51h denote thyristor switches composed of a pair of reverse blocking three-terminal thyristors connected in reverse parallel. The thyristor tap switching circuit 51 composed of the thyristor switches 51a to 51h A bridge connection is established between each tap of the secondary winding 41b of the transformer 41 and the primary windings 31a and 32a of the series transformers 31 and 32 as shown in FIG.

  Similarly, reference numerals 52a to 52h denote thyristor switches composed of a pair of reverse-blocking three-terminal thyristors connected in reverse parallel, and the thyristor tap switching circuit 52 composed of the thyristor switches 52a to 52h is used for the adjustment. A bridge connection is made between the tap of the secondary winding 42b of the transformer 42 and the primary windings 32a and 33a of the series transformers 32 and 33 as shown in FIG.

Further, the secondary-side V-phase terminal 2 </ b> V is connected to the primary windings 41 a and 42 a of the adjustment transformers 41 and 42 and the secondary winding 32 b of the series transformer 32.
The primary windings 41a and 42a of the adjusting transformers 41 and 42 are provided with 24% / 76% taps, and the secondary windings 41b and 42b of the adjusting transformers 41 and 42 are 4% / 12% / Has 8% taps.

Next, the operation of the instantaneous voltage drop prevention device according to the first embodiment of the present invention will be described.
In the configuration shown in FIGS. 1 and 2, in order to operate as an instantaneous voltage drop prevention device, the primary winding tap of the adjustment transformers 41 and 42 is selected to be 24%, and the voltage drop (%) of the system is reduced. Accordingly, the thyristor switches 51a to 51h and 52a to 52h are switched in accordance with a table as shown in Table 1 prepared in advance.

  By switching the thyristor switches 51a to 51h and 52a to 52h of the thyristor tap switching circuits 51 and 52 to a predetermined conduction state according to a previously prepared table as shown in Table 1, the series transformer 31, A predetermined voltage that can compensate for the instantaneous voltage drop is applied to the primary windings 31a, 32a, and 33a of 32 and 33, and the instantaneous voltage drop can be prevented at a high speed.

According to this embodiment, it can be applied as a circuit of an instantaneous voltage drop prevention device capable of compensating for an instantaneous voltage drop of 0 to 48%.
When the voltage drop level to be compensated is to be changed, the number of thyristor switches of the thyristor tap switching circuits 51 and 52, the tap ratio of the primary windings 41a and 42a of the adjustment transformers 41 and 42, and the secondary winding 41b. 42b and the tap ratio may be changed.

  Further, the thyristor taps are provided at the same time when the tap ratios of the secondary windings 41b and 42b of the adjustment transformers 41 and 42 are provided at equal intervals or the number of taps of the secondary windings 41b and 42b of the adjustment transformers 41 and 42 is changed. Even if the number of thyristor switches of the switching circuits 51 and 52 is changed, it can be applied as a circuit of the instantaneous voltage drop prevention device of the present embodiment.

For example, FIG. 3 shows a circuit configuration when the tap ratios of the secondary windings 41b and 42b of the adjustment transformers 41 and 42 are provided at equal intervals to compensate for an instantaneous voltage drop of 0 to 48%.
In the case of the circuit configuration of FIG. 3, the conduction state of the thyristor switch may be switched as shown in Table 2 in accordance with the voltage decrease amount (%).

  In the case of FIGS. 3 and 2, the tap energization state can be changed every time the voltage change amount changes by 4%. However, as shown in FIGS. 4 and 3, the voltage change amount is 8%. It becomes the structure which can change change of the energization state of a tap whenever% changes.

  Next, a second embodiment of the present invention will be described with reference to FIG. In the following description of the embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  The second embodiment of the present invention relates to tap switching control means of an instantaneous voltage drop prevention device, and as shown in FIG. 5, voltage detection means 71 for detecting system voltage, and thyristor tap switching. Tap position determining means 72 for determining ON / OFF command values of thyristor switches (51a to 51h and 52a to 52h in FIG. 2) of the circuit (51 and 52 in FIG. 1), and command values determined by the tap position determining means 72 And a tap operation means 73 for actually turning on / off the thyristor switch based on the above.

Next, the operation of the second embodiment of the present invention will be described with reference to FIGS. 5 and 6 and Table 4. FIG.
The voltage detection means 71 detects the system voltage at high speed and transmits the detected voltage value to the tap position determination means 72.

  In the tap position determining means 72, ON / OFF of the thyristor switches 51a to 51h and 52a to 52h of the thyristor tap switching circuits 51 and 52 shown in FIG. 1 and FIG. 2 according to the voltage drop level transmitted from the voltage detecting means 71. Determine the command value.

For example, FIG. 6 shows the tap position determining means 72 when the instantaneous voltage drop prevention device 1 compensates for a voltage drop of 0 to 48%.
In FIG. 6, the voltage detection value transmitted from the voltage detection means 71 is input to the level detectors 72a1 to 72a12 with hysteresis.

  The level detectors 72a1 to 72a12 with hysteresis are 0.96pu (4% reduction), 0.92pu (8% reduction), 0.88pu (12% reduction), 0.84pu (16% reduction), 0.80pu (reduction amount). 20%), 0.76pu (24% reduction), 0.72pu (28% reduction), 0.68pu (32% reduction), 0.64 (36% reduction), 0.60 (40% reduction), 0.56 The thresholds of pu (44% drop) and 0.52pu (48% drop) are set, and the input voltage detection value is compared with this threshold value. In this case, “1” is output.

The outputs of the level detectors 72a1 to 72a12 with hysteresis are input to the on-delay means 72b1 to 72b12.
In the on-delay means 72b1 to 72b12, different delay times are set so that the larger the voltage drop amount, the faster the detection can be made.

That is, the delay time is set so that 72b1>72b2>72b3>72b4>72b5>72b6>72b7>72b8>72b9>72b10>72b11> 72b12 ".
The output of the on-delay means 72b1 to 72b12 is input to the output means 72c1 to 72c12, and the output means 72c1 to 72c12 outputs a value of 0 to 12 along with the on operation of the on-delay means 72b1 to 72b12. This is input to the decrease amount detection means 72d.

  The maximum value selection / voltage drop amount detection means 72d extracts the maximum value from the output values output as the on-delay means 72b1 to 72b12 are turned on, recognizes it as the current voltage drop amount, and rise detection means To 72e.

  In the rising edge detection means 72e, the previous voltage drop amount (maximum value selection / previous maximum value input from the voltage drop amount detection means 72d) and the newly input voltage drop amount (maximum value selection / voltage drop amount detection means). The maximum value newly input from 72d) is compared, and when the newly input value becomes larger than the previous value, it is determined that “voltage drop has occurred” and a tap command operation signal pulse is output. At the same time, the current voltage drop level (value of 0 to 12) is transmitted to the hold means 72f during the tap operation.

  When the tap command operation signal pulse is generated, the hold means 72f during the tap operation holds the control for a certain period of time, and supplies the current voltage drop level (0-12) to the tap position command operation means 72g and the falling detection means 72h. Value).

  A table corresponding to Table 4 is prepared in advance for the tap position command operation means 72g, and the ON / OFF pattern of the conduction thyristor corresponding to the voltage drop level (value of 0 to 12) is extracted, and the ON / OFF of the thyristor is extracted. The OFF operation command and the thyristor conduction pattern are transmitted to the tap operation means 73 shown in FIG.

  The falling detection means 72h compares the previous voltage drop amount with the newly input voltage drop amount, and if the newly input value is smaller than the previous value, the "power supply side voltage is "Return" is determined, a tap command operation signal pulse is output, and the current voltage drop level (value of 0 to 12) is transmitted to the hold means 72i during the tap operation.

  When the tap command operation signal pulse is generated, the tap operation hold means 72i holds the control for a certain period of time and transmits the current voltage drop level (value of 0 to 12) to the tap position recovery operation means 72j.

  Similarly to the tap position command operation means 72g, a table corresponding to Table 4 is prepared in advance in the tap position recovery operation means 72j, and the conduction thyristor ON / OFF corresponding to the voltage drop level (value of 0 to 12) is prepared. The pattern is extracted, and the thyristor ON / OFF operation command and the thyristor conduction pattern are transmitted to the tap operation means 73 of FIG.

  The tap operation means 73 turns on the thyristor switches 51a to 51h and 52a to 52h based on the thyristor ON / OFF operation command and the thyristor conduction pattern transmitted from the tap position command operation means 72g or the tap position restoration operation means 72j. Arc or extinguish.

  For example, when the voltage drop level is 12, the thyristor switch 51a and the thyristor switch 51h, the thyristor switch 52a and the thyristor switch 52h are fired, and the other thyristor switches are extinguished.

  In this way, the tap operating means 73 is based on the command from the tap position command operating means 72g when an instantaneous voltage drop occurs, and based on the command from the tap position recovery operating means 72j when the voltage is restored. Operates ON / OFF of thyristor.

  FIG. 7 is a schematic flowchart showing the operation of the second embodiment. In FIG. 7, S1 is a step of starting control of the instantaneous voltage drop prevention device shown in the second embodiment, and S2 is a voltage drop. A step of initializing the level; S3, a step of detecting the power supply side voltage; S41 to S4n, a step of performing level detection using the power supply side voltage as an input; S51 to S5n: a step of delaying the output of S41 to S4n on; Is a step of outputting 1 when the on-delay of S51 is turned on, S62 is a step of outputting 2 when the on-delay of S52 is turned on, S63 is a step of outputting 3 when the on-delay of S53 is turned on, S6n is a step of outputting n when the on-delay of S5n is turned on, and S7 is to extract the maximum value from the outputs of S61 to S6n. Step S8 is detected last time: the power supply side voltage is compared with the current power supply side voltage, and if the previous value and the current value are the same, the process proceeds to S13, and if the previous value is different from the current value, the process proceeds to S9. Step, S9 is a step for holding control to enter the tap switching process, S10 is a step for turning off all thyristor switches once, and S11 is a step for turning on the thyristor switch corresponding to the current voltage level from the prepared table. Step for extracting / OFF pattern, step S12 for turning on a predetermined thyristor switch according to the ON / OFF pattern of the extracted thyristor switch, and step S13 for terminating the control of the instantaneous voltage drop prevention device shown in the second embodiment The step of determining whether or not to perform, S14 determines the current voltage level when the control is continued. Times of returning and processing to step S3 held as voltage levels, S15 is a step for terminating the control of the instantaneous voltage drop prevention device shown in the second embodiment.

  According to the present embodiment, the instantaneous voltage drop prevention device can be controlled so as to compensate for the instantaneous voltage drop of 0 to 48% in the circuit configured with the circuit configuration of the first embodiment. .

Next, a third embodiment of the present invention will be described with reference to FIGS.
In the instantaneous voltage drop prevention device 1 according to the third embodiment of the present invention, as shown in FIG. 8A, the primary winding 31a of the series transformer 31 and the primary winding 32a of the series transformer 32 are provided. A first bypass circuit 61 is interposed therebetween, and a second bypass circuit 62 is interposed between the primary winding 32a of the series transformer 32 and the primary winding 33a of the series transformer 33, respectively, and the thyristor tap switching circuit 51, The primary windings 31a, 32a and 32a, 33a of the series transformer 31 are short-circuited while bypassing 52.

  As shown in FIG. 8B, the bypass circuit 61 includes a thyristor switch 61a and a resistor 61b connected in series. Similarly, the bypass circuit 62 is connected in series as shown in FIG. 8C. It is composed of a thyristor switch 62a and a resistor 62b.

Next, the operation of the instantaneous voltage drop prevention device according to the third embodiment of the present invention will be described.
When switching the thyristor switches 51a to 51h and 52a to 52h to a predetermined conducting state, the conducting thyristor switch is turned off and then a new thyristor switch is turned on. At the same time when the conducting thyristor switch is turned off. The thyristor switches 61a and 62a of the bypass circuits 61 and 62 are turned on, and the new thyristor switch is turned on. At the same time, the thyristor switches 61a and 62a of the bypass circuits 61 and 62 are turned off.

  In this way, by switching the thyristor switch at the time of voltage drop compensation or at the time of switching the thyristor switch at the time of voltage recovery, the bypass circuits 61 and 62 are made conductive to reduce the load side voltage generated at the time of switching the thyristor switch. Alternatively, it is possible to suppress the overvoltage of the load side voltage that occurs when the thyristor switch is switched at the time of voltage recovery.

  According to the present embodiment, if the thyristor switch conduction state is switched in accordance with the amount of voltage decrease (%) as in the first embodiment, it is 0 to 48% as shown in Table 5. It can be applied as a circuit for an instantaneous voltage drop prevention device that can compensate for an instantaneous voltage drop, and when the load side voltage drops when the thyristor switch is switched when the power supply voltage drops or when the power supply voltage is restored It is possible to suppress the overvoltage of the load side voltage that occurs when the thyristor switch is switched.

Next, a fourth embodiment of the present invention will be described with reference to FIG. 10 and FIG.
In the instantaneous voltage drop prevention device according to the fourth embodiment of the present invention, the voltage detection means 71 for detecting the voltage of the system and the thyristor switch (51a in FIG. 9) of the thyristor tap switching circuit (51, 52 in FIG. 8). To 51h and 52a to 52h) tap position determining means 72N for determining ON / OFF command values, and tap operating means 73 for actually turning ON / OFF the thyristor switch based on the command values determined by the tap position determining means 72N. And bypass operating means 74 for turning ON / OFF the thyristor switches (61a and 62a in FIG. 9) of the bypass circuit based on the ON / OFF command of the bypass circuit output from the tap position determining means 72N. .

Next, the operation of the fourth embodiment of the present invention will be described with reference to FIGS.
In the instantaneous voltage drop prevention device according to the present embodiment, in addition to the operation of the second embodiment, the tap operation hold means 72f holds the control for a certain time when the tap command operation signal pulse is generated. At the same time, the current voltage drop level (value of 0 to 12) is transmitted to the bypass ON command means 72x and the fall detection means 72h.

  The bypass ON command means 72x transmits to the bypass operation means 74 of FIG. 10 so as to turn on the thyristor switches 61a and 62a of the bypass circuits 61 and 62, and at the same time the voltage drop level (0-12) to the tap position command operation means 72g. Value).

  A table corresponding to Table 4 is prepared in advance for the tap position command operation means 72g, and ON / OFF patterns of conduction thyristors 51a to 51h and 52a to 52h corresponding to voltage drop levels (values of 0 to 12) are prepared. The thyristor ON / OFF operation command and the conduction patterns of the thyristors 51a to 51h and 52a to 52h are transmitted to the tap operation means 73 of FIG.

  The falling detection means 72h compares the previous voltage drop level with the newly input voltage drop level, and if the newly input value is smaller than the previous value, “the power supply side voltage is restored. And a tap command operation signal pulse is output, and the current voltage drop level (value of 0 to 12) is transmitted to the hold means 72i during the tap operation.

  When the tap command operation signal pulse is generated, the tap operation hold means 72i holds the control for a certain period of time and transmits the current voltage drop level (value of 0 to 12) to the bypass ON command means 72y.

  The bypass ON command means 72y transmits to the bypass operation means 74 of FIG. 10 so as to turn on the thyristor switches 61a and 62a of the bypass circuits 61 and 62, and also supplies the current voltage drop level (0 to 12) to the tap position recovery operation means 72j. Value).

  Similarly to the tap position command operation means 72g, a table corresponding to Table 1 is prepared in advance in the tap position recovery operation means 72j, and the conduction thyristors 51a to 51h corresponding to the voltage drop level (values 0 to 12) and The ON / OFF patterns 52a to 52h are extracted, and the thyristor ON / OFF operation command and the conduction patterns of the thyristors 51a to 51h and 52a to 52h are transmitted to the tap operation means 73 of FIG.

  The tap operation means 73 turns on each thyristor (51a to 51h and 52a to 52h) based on the thyristor ON / OFF operation command and the thyristor conduction pattern transmitted from the tap position command operation means 72g or the tap position restoration operation means 72j. At the same time that the arc is extinguished or extinguished, a command to extinguish the thyristor switches 61 a and 62 a of the bypass circuits 61 and 62 is transmitted to the bypass operating means 74.

  In this way, the tap operating means 73 is based on the command from the tap position command operating means 72g when an instantaneous voltage drop occurs, and based on the command from the tap position recovery operating means 72j when the voltage is restored. The thyristor switches 61a and 62a of the bypass circuits 61 and 62 are operated to extinguish the arc simultaneously with the ON / OFF operation of the thyristor.

  The bypass operation means 74 ignites the thyristor switches 61a and 62a of the bypass circuits 61 and 62 based on the instructions of the bypass ON instruction means 72x and 72y, and the bypass circuits 61 and 62 of the bypass circuits 61 and 62 based on the instructions from the tap operation means 73. The thyristor switches 61a and 62a are extinguished.

  FIG. 12 is a schematic flowchart showing the operation of the fourth embodiment. In FIG. 12, S1 is a step of starting control of the instantaneous voltage drop prevention device shown in the fourth embodiment, and S2 is a voltage drop. A step of initializing the level; S3, a step of detecting a power supply side voltage; S41 to S41n, a step of performing level detection using the power supply side voltage as an input; S51 to S51n: a step of delaying the output of S41 to S41n on; Is a step of outputting 1 when the on-delay of S51 is turned on, S62 is a step of outputting 2 when the on-delay of S52 is turned on, S63 is a step of outputting 3 when the on-delay of S53 is turned on, S6n is a step of outputting n when the on-delay of S5n is turned on, S7 is the maximum from the output of S61 to S6n In step S8, the power supply side voltage detected last time is compared with the current power supply side voltage, and if the previous value and the current value are the same, the process proceeds to S13, and if the previous value and the current value are different, the process proceeds to S9. Step S9 is a step for holding control to enter the tap switching process, S10 is a step for turning off all thyristor switches once, S10a is a step for turning on thyristor switches of the bypass circuit, and S11 is prepared. Extracting a thyristor switch ON / OFF pattern that matches the current voltage level from the existing table, S12 turning on a predetermined thyristor switch according to the extracted ON / OFF pattern of the thyristor switch, and S12a being a thyristor switch of the bypass circuit Is turned off, S13 is the first Determining whether to end the control of the instantaneous voltage drop prevention device shown in the embodiment, S14 is a step of holding the current voltage level as the previous voltage level and returning the process to S3 when the control is continued; S15 is a step of ending the control of the instantaneous voltage drop prevention device shown in the fourth embodiment.

  According to the present embodiment, it can be applied as a circuit of an instantaneous voltage drop prevention device capable of compensating for an instantaneous voltage drop of 0 to 48%, and at the time of thyristor switch switching when the power supply voltage drops. It is possible to control so as to suppress a decrease in the load side voltage generated at the time of switching or an overvoltage of the load side voltage generated at the time of switching the thyristor switch when the power supply side voltage is restored.

  The processing shown in the flowchart and the second embodiment shown in FIG. 7 or the processing shown in the flowchart and the fourth embodiment shown in FIG. 12 is installed in the computer as a program to be processed on the computer. Has been.

In FIG. 13, 81 is a computer and 91 is a program recording medium.
The computer 81 for realizing the control of the instantaneous voltage drop prevention device shown in the second embodiment and the fourth embodiment prevents the instantaneous voltage drop recorded on a recording medium such as a magnetic disk, an optical disk, or a semiconductor memory. By reading the recording medium 91 of the program that realizes the control of the device and the control of the instantaneous voltage drop prevention device is operated by this program, the processing shown in the second embodiment or the fourth embodiment is executed. It functions as a control of the instantaneous voltage drop prevention device.

  According to the present embodiment, the computer can function as a computer that controls the instantaneous voltage drop prevention device.

1 is a circuit diagram of an instantaneous voltage drop prevention device according to a first embodiment of the present invention. The circuit diagram which shows the detail of the thyristor tap switching circuit in the instantaneous voltage drop prevention device by the 1st Embodiment of this invention. . The circuit diagram which shows the 1st modification of the 1st Embodiment of this invention. The circuit diagram which shows the 2nd modification of the 1st Embodiment of this invention. The block diagram which shows the control circuit of the instantaneous voltage drop prevention apparatus by the 2nd Embodiment of this invention. The block diagram which shows the control circuit of the instantaneous voltage drop prevention apparatus by the 2nd Embodiment of this invention. The flowchart which shows the effect | action of the 2nd Embodiment of this invention. It is a figure which shows the instantaneous voltage drop prevention apparatus by the 3rd Embodiment of this invention, (a) is a circuit diagram, (b), (c) is an enlarged block diagram of the principal part. The circuit diagram which shows the more detailed structure of the instantaneous voltage drop prevention apparatus by the 3rd Embodiment of this invention. The block diagram which shows the control circuit of the instantaneous voltage drop prevention apparatus by the 4th Embodiment of this invention. The block diagram which shows the control circuit of the instantaneous voltage drop prevention apparatus by the 4th Embodiment of this invention. The flowchart which shows the effect | action of the 4th Embodiment of this invention. The block diagram for demonstrating the calculation function in the instantaneous voltage drop prevention apparatus by embodiment of this invention. The circuit diagram of the tap type voltage regulator (TVR) using the conventional thyristor switch.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Instantaneous voltage drop prevention apparatus, 1U ... U-phase primary terminal, 1V ... V-phase primary terminal, 1W ... W-phase primary terminal, 2U ... U-phase secondary terminal, 2V ... V-phase secondary terminal, 2W ... W-phase secondary Next terminal, 31, 32, 33 ... Series transformer, 31a, 32a, 33a ... Primary winding of series transformer, 31b, 32b, 33b ... Secondary winding of series transformer, 41, 42 ... Adjusting transformer, 41a, 42a ... primary winding of adjusting transformer, 41b, 42b ... secondary winding of adjusting transformer, 51, 52 ... thyristor tap switching circuit, 51a-51h, 52a-52h ... thyristor switch, 61, 62 ... bypass Circuit, 61a, 62a ... Thyristor switch for bypass circuit ON / OFF, 61b, 62b ... Resistance element of bypass circuit, 71 ... Voltage detection means, 72 ... Tap position determination means, 72a1-72a12 ... Hysteresis Level detectors 72b1 to 72b12 ... on delay means, 72c1 to 72c12 ... output means, 72d ... maximum value selection / voltage drop amount detection means, 72e ... rise detection means, 72f, 72i ... hold processing means, 72g ... tap position command Operation means, 72h ... Falling detection means, 72j ... Tap position recovery operation means, 73 ... Tap operation means, 74 ... Bypass operation means.

Claims (8)

  A series transformer connected in series to the line, a primary winding and a secondary winding with a tap, and the primary winding is connected to the load side of the secondary winding of the series transformer; The adjustment transformer configured to apply a voltage to the primary winding of the series transformer, and a plurality of thyristor switches formed by connecting a pair of thyristors in reverse parallel, and the secondary winding of the adjustment transformer The thyristor tap switching circuit connected between the primary winding of the series transformer, and the thyristor switch conduction of the thyristor tap switching circuit according to a table prepared in advance according to the amount of voltage decrease on the power supply side An instantaneous voltage drop prevention device characterized in that the state is switched and the tap of the primary winding of the adjustment transformer is switched in the direction of increasing the voltage.   The thyristor tap switching circuit is configured to determine a voltage detection unit that detects a voltage on the power supply side of the line, a decrease amount of the voltage detected by the voltage detection unit, and determine a tap position of the secondary winding of the adjustment transformer. 2. A tap position determining means for determining, and a tap operation means for turning on / off a thyristor switch of the thyristor switching circuit based on the tap position determined by the tap position determining means. The described instantaneous voltage drop prevention device.   Between the primary winding of the series transformer and the thyristor tap switching circuit, an anti-parallel connection thyristor switch that bypasses the thyristor tap switching circuit and shorts the primary winding side of the series transformer and a resistance element. 2. The instantaneous voltage drop prevention device according to claim 1, further comprising a bypass circuit. The thyristor tap switching circuit is configured to detect a voltage detection unit for detecting a voltage on a power supply side of the electric line, and determine a decrease amount of the voltage detected by the voltage detection unit, and tap position of the secondary winding of the adjustment transformer Tap position determining means for determining the bypass circuit, bypass operating means for turning ON / OFF the anti-parallel connection thyristor switch of the bypass circuit, tap position determined by the tap position determining means, and ON / OFF of the bypass circuit by the bypass operating means 4. The instantaneous voltage drop prevention device according to claim 3 , further comprising tap operation means for turning on / off a thyristor switch of the thyristor tap switching circuit based on a state.   A voltage converting means connected in series to the line, for changing the voltage of the line, and a primary winding and a secondary winding provided with taps, the primary winding of the secondary winding of the voltage converting means; A voltage adjusting means connected to the load side for applying a voltage to the primary winding of the voltage transforming means, and a plurality of thyristor switches formed by connecting a pair of thyristors in reverse parallel are bridge-connected, and the secondary of the voltage adjusting means A switch connected between the winding and the primary winding of the voltage transformation means, and a means for switching the tap, and according to the amount of voltage drop on the power supply side, the conduction state of the thyristor switch is determined according to a table prepared in advance. A method for preventing an instantaneous voltage drop, characterized in that the tap of the primary winding of the voltage adjusting means is switched in the direction of increasing the voltage.   The tap switching means determines a tap position of the secondary winding of the voltage adjusting means by determining a voltage detecting means for detecting a voltage on the power source side of the line and a voltage decrease amount detected by the voltage detecting means. 6. The instantaneous voltage drop prevention according to claim 5, further comprising: a tap position determining means for performing ON / OFF operation of the thyristor switch based on the tap position determined by the tap position determining means. Method.   Between the primary winding of the voltage transformation means and the tap switching means, a bypass composed of an anti-parallel connection thyristor switch that bypasses the tap switching means and short-circuits the primary winding side of the voltage transformation means and a resistance element 6. An instantaneous voltage drop prevention method according to claim 5, further comprising means. The tap switching means is configured to determine a voltage detection means for detecting a voltage on the power supply side of the electric line and a decrease amount of the voltage detected by the voltage detection means, and determine a tap position of the secondary winding of the voltage adjustment means. Tap position determining means for determining, bypass operating means for turning on / off the antiparallel connection thyristor switch of the bypass circuit, tap position determined by the tap position determining means, and ON / OFF of the bypass circuit by the bypass operating means 8. The instantaneous voltage drop prevention method according to claim 7 , further comprising tap operation means for turning on / off a thyristor switch of the tap switching means based on a state.

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