A single-phase auto-coupling contactless intelligent voltage stabilizer and control method thereof

Abstract

The present invention discloses a single-phase self-coupled contactless intelligent voltage stabilizer and a control method thereof, wherein the intelligent voltage stabilizer comprises: an autotransformer having an output end and N voltage regulating ends, the voltage regulating end of each autotransformer being connected to the output end of the autotransformer via a voltage regulating thyristor, and the first voltage regulating end is also connected to the neutral line via a step-down thyristor, and the last voltage regulating end is also connected to the neutral line via a step-up thyristor; a main control circuit is used to control the N voltage regulating thyristors of the autotransformer to be turned on in time-sharing manner, and the main control circuit is also used to output a boost start signal to the step-up thyristor and output a step-down shut-down signal to the step-down thyristor; or, to output a boost shut-down signal to the step-up thyristor and output a step-down start signal to the step-down thyristor; a protection circuit is used to control the step-down thyristor to shut down when receiving a boost start signal; and to control the step-up thyristor to shut down when receiving a step-down start signal. The technical solution of the present invention can reduce the short-circuit risk of the intelligent voltage stabilizer.

Description

Technical Field

[0001] The present invention relates to the technical field of contactless intelligent voltage stabilizers, and in particular to a single-phase auto-coupling contactless intelligent voltage stabilizer and a control method thereof. Background Art

[0002] At present, the single-phase auto-coupling contactless intelligent voltage stabilizer is more competitive in the market in smart home applications because it can save one transformer material and reduce the production cost of the voltage stabilizer compared to the single-phase contactless voltage stabilizer design with dual transformers.

[0003] However, the boost and buck gears of the single-phase auto-coupling contactless intelligent voltage stabilizer need to be implemented by boost thyristors and buck thyristors respectively, which will increase the short-circuit risk of the single-phase free contactless intelligent voltage stabilizer after being used for a period of time. Summary of the invention

[0004] The main purpose of the present invention is to provide a single-phase auto-coupling contactless intelligent voltage stabilizer and a control method thereof, aiming to reduce the short circuit risk of a single-phase auto-coupling transformer.

[0005] To achieve the above object, the present invention provides a single-phase auto-coupling contactless intelligent voltage stabilizer, which comprises:

[0006] An autotransformer having an output end and N voltage regulating ends, wherein the voltage regulating end of each autotransformer is connected to the output end of the autotransformer via a voltage regulating thyristor, and wherein the first voltage regulating end is also connected to the neutral line via a step-down thyristor, and wherein the last voltage regulating end is also connected to the neutral line via a step-up thyristor, and N is greater than or equal to 2;

[0007] A main control circuit, wherein the boost control terminal of the main control circuit is connected to the controlled terminal of the boost thyristor, the buck control terminal of the main control circuit is connected to the controlled terminal of the buck thyristor, and the N control terminals of the main control circuit are respectively connected one-to-one with the controlled terminals of the N voltage-regulating thyristors; the main control circuit is used to control the N voltage-regulating thyristors to be turned on in a time-sharing manner;

[0008] The main control circuit is also used to output a boost start signal to the boost thyristor and output a buck stop signal to the buck thyristor; or, to output a boost stop signal to the boost thyristor and output a buck start signal to the buck thyristor;

[0009] The protection circuit is respectively connected to the boost control end and the buck control end of the main control circuit, and the controlled ends of the boost thyristor and the buck thyristor; the protection circuit is used to control the buck thyristor to be turned off when receiving the boost start signal; and is used to control the boost thyristor to be turned off when receiving the buck start signal.

[0010] Optionally, the protection circuit includes:

[0011] a signal output circuit, connected to the boost control terminal and the buck control terminal of the main control circuit respectively, and used to output a first control signal from the first output terminal when receiving the boost start signal; and used to output a second control signal from the second output terminal when receiving the buck start signal;

[0012] A switch circuit is connected to the controlled end of the boost thyristor, the controlled end of the buck thyristor, and the first output end and the second output end of the signal conversion circuit. The switch circuit is used to control the buck thyristor to turn off after receiving the first control signal; and to control the boost thyristor to turn off after receiving the second control signal.

[0013] Optionally, the signal output circuit may include:

[0014] a first signal conversion circuit, wherein the input end of the first signal conversion circuit is used to be connected to the boost control end of the main control circuit, and the output end of the first signal conversion circuit is the first output end of the signal output circuit; the first signal conversion circuit is used to perform level inversion on the boost start signal, and output the level-inverted boost start signal as the first control signal;

[0015] A second signal conversion circuit, wherein the input end of the second signal conversion circuit is used to be connected to the buck control end of the main control circuit, and the output end of the first signal conversion circuit is the second output end of the signal output circuit; the second signal conversion circuit is used to perform level inversion on the buck start signal, and output the level-inverted buck start signal as a second control signal.

[0016] Optionally, a level value of the first control signal is opposite to a level value of the boost start signal, and a level value of the second control signal is opposite to a level value of the buck start signal.

[0017] Optionally, the switch circuit includes:

[0018] A boost switch circuit, connected to the controlled end of the boost thyristor and the second output end of the signal conversion circuit respectively, and the boost switch circuit is used to control the boost thyristor to turn off when receiving the second control signal;

[0019] The step-down switch circuit is connected to the controlled end of the step-down thyristor and the first output end of the signal conversion circuit respectively. The step-up switch circuit is used to control the step-down thyristor to be turned off when receiving the first control signal.

[0020] Optionally, the boost switch circuit includes a first switch device, a first resistor, a second resistor and a third resistor;

[0021] The controlled end of the first switch device is connected to the second control signal via the first resistor, and the controlled end of the first switch device is also connected to the preset voltage via the second resistor. The input end of the first switch device is connected to the controlled end of the boost thyristor, and the output end of the first switch device is grounded via the third resistor.

[0022] Optionally, the step-down switch circuit includes a second switch device, a fourth resistor, a fifth resistor and a sixth resistor;

[0023] The controlled end of the second switch device is connected to the first control signal via the fourth resistor, and the controlled end of the second switch device is also connected to the preset voltage via the fifth resistor. The input end of the second switch device is connected to the controlled end of the boost thyristor, and the output end of the second switch device is grounded via the sixth resistor.

[0024] Optionally, the boost switch circuit and the buck switch circuit are interlocked.

[0025] The present invention also proposes a control method for a single-phase auto-coupling contactless intelligent voltage regulator, the control method for the single-phase auto-coupling contactless intelligent voltage regulator comprising:

[0026] If a boost control signal is output, a first control signal is generated and output to the protection circuit, so that the protection circuit controls the step-down thyristor to be turned off according to the received first control signal;

[0027] If the step-down control signal is output, a second control signal is generated and output to the protection circuit, so that the protection circuit controls the step-up thyristor to be turned off according to the received second control signal.

[0028] The technical solution of the present invention sets a protection circuit so that even if the falling edge of the boost start signal switching to the boost stop signal and the falling edge of the buck start signal switching to the buck stop signal are both lengthened, the protection circuit can ensure that the boost thyristor and the buck thyristor are not turned on at the same time, thereby reducing the short circuit risk of the single-phase autotransformer and helping to improve the safety of the single-phase autotransformer contactless intelligent voltage stabilizer. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0030] Figure 1 This is a module schematic diagram of a single-phase auto-coupling contactless intelligent voltage stabilizer according to an embodiment of the present invention;

[0031] Figure 2 This is another module schematic diagram of a single-phase auto-coupling contactless intelligent voltage stabilizer according to an embodiment of the present invention;

[0032] Figure 3 It is another module schematic diagram of the single-phase auto-coupling contactless intelligent voltage stabilizer according to the first embodiment of the present invention;

[0033] Figure 4 A circuit diagram of a boost switch circuit in an embodiment of a single-phase auto-coupling contactless intelligent voltage stabilizer of the present invention;

[0034] Figure 5 It is a circuit diagram of a step-down switch circuit in an embodiment of a single-phase auto-coupling contactless intelligent voltage stabilizer of the present invention;

[0035] Figure 6 The figure is a flow chart of a control method of a single-phase auto-coupling contactless intelligent voltage stabilizer according to the second embodiment of the present invention.

[0036] Description of Figure Numbers:

[0037]

[0038] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] In addition, in the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0041] Embodiment 1

[0042] The invention provides a single-phase auto-coupling contactless intelligent voltage stabilizer.

[0043] Reference Figure 1 , the single-phase auto-coupling contactless intelligent voltage stabilizer comprises:

[0044] An autotransformer T has an output end and N voltage regulating ends, each of the voltage regulating ends of the autotransformer T is connected to the output end of the autotransformer T via a voltage regulating thyristor, and the first voltage regulating end is also connected to the neutral line N via a step-down thyristor Db, and the last voltage regulating end is also connected to the neutral line N via a step-up thyristor Da, N is greater than or equal to 2;

[0045] The main control circuit 100, the boost control terminal of the main control circuit 100 is connected to the controlled terminal of the boost thyristor Da, the buck control terminal of the main control circuit 100 is connected to the controlled terminal of the buck thyristor Db, and the N control terminals of the main control circuit 100 are respectively connected one-to-one with the controlled terminals of the N voltage regulating thyristors ( Figures 1 to 5 The main control circuit 100 is used to control N voltage regulating thyristors to conduct in a time-sharing manner;

[0046] The main control circuit 100 is also used to output a boost start signal S1 to the boost thyristor Da and output a buck stop signal S4 to the buck thyristor Db; or, to output a boost stop signal S3 to the boost thyristor Da and output a buck start signal S2 to the buck thyristor Db;

[0047] The protection circuit 200 is respectively connected to the boost control end and the buck control end of the main control circuit 100, and the controlled ends of the boost thyristor Da and the buck thyristor Db; the protection circuit 200 is used to control the buck thyristor Db to be turned off when receiving the boost start signal S1; and is used to control the boost thyristor Da to be turned off when receiving the buck start signal S2.

[0048] In this embodiment, the autotransformer T may have an iron core and a first coil and a second coil respectively wound on the iron core. Among them, the first end of the first coil can be used as the positive input end of the single-phase auto-coupling contactless intelligent voltage regulator and used to connect to the live wire P of the power grid, and the second end of the first coil can be used as the output end of the single-phase auto-coupling contactless intelligent voltage regulator; the second coil can be a voltage regulating coil, and the N ports of the second coil can be the N voltage regulating ends of the autotransformer T, each port of the second coil can be connected to the output end of the autotransformer T through a thyristor (i.e., a voltage regulating thyristor), and the first port of the N ports of the second coil can be connected to the negative input end of the single-phase auto-coupling contactless intelligent voltage regulator through a thyristor (i.e., a step-down thyristor Db), and the last port of the N ports of the second coil can be connected to the negative input end of the single-phase auto-coupling contactless intelligent voltage regulator through a thyristor (i.e., a step-up thyristor Da), and the negative input end of the single-phase auto-coupling contactless intelligent voltage regulator can be used to connect to the neutral line N.

[0049] The main control circuit 100 can be implemented by a microprocessor such as MCU, DSP or FPGA; or, it can also be implemented by a dedicated main control chip. When determining that the single-phase auto-coupling contactless intelligent voltage regulator needs to be switched to the boost level, the main control circuit 100 can output a boost start signal S1 to control the boost thyristor Da to turn on, output a buck close signal S4 to control the buck thyristor Db to turn off, and output a voltage regulation start signal to any one of the N voltage regulation thyristors except the last one to turn on the voltage regulation thyristor, thereby switching the single-phase auto-coupling contactless intelligent voltage regulator to the boost state. The main control circuit 100 can switch on different voltage regulation thyristors to put the single-phase auto-coupling contactless intelligent voltage regulator in different boost levels, and the output voltage of the single-phase auto-coupling contactless intelligent voltage regulator is greater than the input voltage at each boost level.

[0050] When determining that the single-phase auto-coupling contactless intelligent voltage regulator needs to be switched to the step-down level, the main control circuit 100 can also output a step-down start signal S2 to control the step-down thyristor Db to turn on, output a step-up close signal S3 to control the step-up thyristor Da to turn off, and output a voltage regulation start signal to any one of the N voltage regulation thyristors except the last one to turn on the voltage regulation thyristor, thereby switching the single-phase auto-coupling contactless intelligent voltage regulator to the step-down state. The main control circuit 100 can switch on different voltage regulation thyristors to put the single-phase auto-coupling contactless intelligent voltage regulator in different step-down levels, and the output voltage of the single-phase auto-coupling contactless intelligent voltage regulator is less than the input voltage at each step-down level.

[0051] When determining that the single-phase auto-coupling contactless intelligent voltage regulator needs to be switched to the maintenance gear, the main control circuit 100 can also output a boost start signal S1 to control the boost thyristor Da to turn on, output a buck stop signal S4 to control the buck thyristor Db to turn off, and output a voltage regulation start signal to the last voltage regulating thyristor among the N voltage regulating thyristors to turn on the voltage regulating thyristor; or, it can also output a buck start signal S2 to control the buck thyristor Db to turn on, output a boost stop signal S3 to control the boost thyristor Da to turn off, and output a voltage regulation start signal to the first voltage regulating thyristor among the N voltage regulating thyristors to turn on the voltage regulating thyristor, thereby switching the single-phase auto-coupling contactless intelligent voltage regulator to the maintenance state, and the output voltage of the single-phase auto-coupling contactless intelligent voltage regulator in the maintenance gear is equal to the input voltage.

[0052] The boost start signal S1, the buck start signal S2 and the voltage regulation start signal can all be high level signals, and the boost shut down signal S3, the buck shut down signal S4 and the voltage regulation shut down signal for controlling the voltage regulation thyristor to shut down can all be low level signals. The wiring method of the above-mentioned autotransformer T can make the single-phase auto-coupling contactless intelligent voltage stabilizer have N-1 boost gears, N-1 buck gears and two maintenance gears, and N is 5 as an example for illustration. At this time, the five voltage-regulating thyristors are the first voltage-regulating thyristor D1, the second voltage-regulating thyristor D2, the third voltage-regulating thyristor D3, the fourth voltage-regulating thyristor D4 and the fifth voltage-regulating thyristor D5. The four boost gears of the single-phase auto-coupling contactless intelligent voltage stabilizer and the thyristors turned on corresponding to each boost gear are: the first boost gear (the first voltage-regulating thyristor D1 and the boost thyristor Da are turned on), the second boost gear (the second voltage-regulating thyristor D2 and the boost thyristor Da are turned on), the third boost gear (the third voltage-regulating thyristor D3 and the boost thyristor Da are turned on), and the fourth boost gear (the fourth voltage-regulating thyristor D4 and the boost thyristor Da are turned on); the single-phase auto-coupling contactless intelligent voltage stabilizer has There are 4 step-down gears and the corresponding thyristors turned on in each step-down gear, namely: the first step-down gear (the fifth voltage-regulating thyristor D5 and the step-down thyristor Db are turned on), the second step-down gear (the fourth voltage-regulating thyristor D4 and the step-down thyristor Db are turned on), the third step-down gear (the third voltage-regulating thyristor D3 and the step-down thyristor Db are turned on), and the fourth step-down gear (the second voltage-regulating thyristor D2 and the step-down thyristor Db are turned on); the single-phase autocoupled contactless intelligent voltage stabilizer has 2 maintaining gears and the corresponding thyristors turned on, namely the first maintaining gear (the fifth voltage-regulating thyristor D5 and the boost thyristor Da are turned on), and the second maintaining gear (the first voltage-regulating thyristor D1 and the step-down thyristor Db are turned on).

[0053] It can be seen from the thyristors turned on in the above-mentioned gears that if the step-up thyristor Da and the step-down thyristor Db are turned on at the same time, a short-circuit fault will occur in the single-phase auto-coupling contactless intelligent voltage stabilizer. Although the prior art avoids the above-mentioned short-circuit fault by preventing the main control circuit 100 from outputting the boost start signal S1 and the buck start signal S2 at the same time, the inventors have found that as the voltage regulator is used for a longer time, the signal output capabilities of the boost control end and the buck control end of the main control circuit 100 will decrease, which is specifically manifested in that the falling edge of switching from the boost start signal S1 to the boost shutoff signal S3 and the falling edge of switching from the buck start signal S2 to the buck shutoff signal S4 are both lengthened, while the rising edge of switching from the boost shutoff signal S3 to the boost start signal S1 and the rising edge of switching from the buck shutoff signal S4 to the buck start signal S2 are almost unchanged, thereby increasing the probability that the controlled ends of the boost thyristor Da and the buck thyristor Db are at a higher level at the same time, thereby increasing the risk of short-circuit faults caused by the boost thyristor Da and the buck thyristor Db being turned on at the same time.

[0054] In view of this problem, the technical solution of the present invention is provided with a protection circuit 200, which can be constructed and implemented by discrete devices and switch devices, wherein the discrete devices include resistors, capacitors and inductors, etc., and the switch devices can be triodes, MOS tubes and thyristors, etc. When the protection circuit 200 receives the boost start signal S1, it can control the corresponding switch devices in itself to turn on according to the boost start signal S1, and at this time, each switch device turned on can pull down the level of the controlled end of the buck thyristor Db, so as to turn off the buck thyristor Db. When the protection circuit 200 receives the buck start signal S2, it can control the corresponding switch devices to turn on according to the buck start signal S2, and at this time, each switch device turned on can pull down the level of the controlled end of the boost thyristor Da, so as to turn off the boost thyristor Da.

[0055] In this way, even if the falling edge of the boost start signal S1 switching to the boost shutoff signal S3 and the falling edge of the buck start signal S2 switching to the buck shutoff signal S4 are both lengthened, the protection circuit 200 can ensure that the boost thyristor Da and the buck thyristor Db will not be turned on at the same time, thereby reducing the short circuit risk of the single-phase autotransformer T, which is beneficial to improving the safety of the single-phase autocontactless intelligent voltage regulator. The single-phase autocontactless intelligent voltage regulator proposed in the present invention belongs to a contactless voltage regulator. Compared with other contactless voltage regulators with other architectures available on the market, it has the advantages of lower cost, higher reliability and no noise. By adopting the autotransformer T, the cost can be effectively reduced while achieving the same voltage stabilization performance, which is convenient for market promotion.

[0056] Reference Figure 2 , the signal conversion circuit comprises:

[0057] The signal output circuit 210 is connected to the boost control terminal and the buck control terminal of the main control circuit 100, respectively, and is used to output a first control signal from a first output terminal when receiving the boost start signal S1; and is used to output a second control signal from a second output terminal when receiving the buck start signal S2;

[0058] The switch circuit 220 is connected to the controlled end of the boost thyristor Da, the controlled end of the buck thyristor Db, and the first output end and the second output end of the signal conversion circuit. The switch circuit 220 is used to control the buck thyristor Db to be turned off after receiving the first control signal; and to control the boost thyristor Da to be turned off after receiving the second control signal.

[0059] In this embodiment, the signal output circuit 210 can perform corresponding level adjustment processing on the received boost start signal S1 and buck start signal S2, for example, increase or decrease the level value of the boost start signal S1 and buck start signal S2, and output the boost start signal S1 and buck start signal S2 after the level adjustment processing as the first control signal and the second control signal respectively. Alternatively, the signal output circuit 210 can also trigger and control the corresponding preset hardware circuit or software program or algorithm to work when receiving the boost control signal and the buck control signal, so as to generate and output the first control signal and the second control signal accordingly.

[0060] The switch circuit 220 can control the corresponding switch devices in itself to conduct when receiving the first control signal, and each switch device that is turned on at this time can pull down the level of the controlled end of the buck thyristor Db, so as to turn off the buck thyristor Db. The switch circuit 220 can also control the corresponding switch devices to conduct according to the buck start signal S2 when receiving the buck start signal S2, and each switch device that is turned on at this time can pull down the level of the controlled end of the boost thyristor Da, so as to turn off the boost thyristor Da.

[0061] Optionally, refer to Figure 3 , the signal output circuit 210 may include:

[0062] A first signal conversion circuit 211, wherein the input end of the first signal conversion circuit 211 is used to be connected to the boost control end of the main control circuit 100, and the output end of the first signal conversion circuit 211 is the first output end of the signal output circuit 210; the first signal conversion circuit 211 is used to perform level inversion on the boost start signal S1, and output the level-inverted boost start signal S1 as a first control signal;

[0063] The second signal conversion circuit 212, the input end of the second signal conversion circuit 212 is used to connect with the buck control end of the main control circuit 100, and the output end of the first signal conversion circuit 211 is the second output end of the signal output circuit 210; the second signal conversion circuit 212 is used to perform level inversion on the buck start signal S2, and output the level-inverted buck start signal S2 as the second control signal.

[0064] In this embodiment, the first signal conversion circuit 211 and the second signal conversion circuit 212 can be implemented by inverters. The first signal conversion circuit 211 can invert the boost start signal S1 of the high level signal into a low level signal, and can output the inverted low level signal as the first control signal; the second signal conversion circuit 212 can invert the buck start signal S2 of the high level signal into a low level signal, and can output the inverted low level signal as the second control signal. In other words, the level value of the first control signal can be opposite to the level value of the boost start signal S1, and the level value of the second control signal can be opposite to the level value of the buck start signal S2, that is, the first control signal and the second control signal can be low level signals.

[0065] It should be noted that since the boost start signal S1 and the buck start signal S2 are responsible for driving the boost thyristor Da and the buck thyristor Db respectively, if the boost start signal S1 and the buck start signal S2 are directly used to trigger the switch circuit 220 to turn off the boost thyristor Da and the buck thyristor Db respectively, the driving capability of the boost start signal S1 and the buck start signal S2 will be reduced. However, the embodiment of the present invention converts the boost start signal S1 and the buck start signal S2 into low-level signals, and then triggers the switch circuit 220 to turn off the boost thyristor Da and the buck thyristor Db respectively, so that the switch circuit 220 can be effectively triggered while reducing the impact on the driving capability. In addition, compared with the design of the dedicated signal output circuit 210, the inverter structure is simple, which is conducive to saving design costs.

[0066] Optionally, refer to Figure 3 , the switch circuit 220 includes:

[0067] A boost switch circuit 221 is connected to the controlled end of the boost thyristor Da and the second output end of the signal conversion circuit respectively, and the boost switch circuit 221 is used to control the boost thyristor Da to turn off when receiving the second control signal;

[0068] The step-down switch circuit 222 is connected to the controlled end of the step-down thyristor Db and the first output end of the signal conversion circuit respectively. The step-up switch circuit 221 is used to control the step-down thyristor Db to be turned off when receiving the first control signal.

[0069] Optionally, refer to Figure 4 , the boost switch circuit 221 includes a first switch device Q1, a first resistor, a second resistor R2 and a third resistor R3;

[0070] The controlled end of the first switch device Q1 is connected to the second control signal via the first resistor R1, and the controlled end of the first switch device Q1 is also connected to the preset voltage VCC via the second resistor R2, the input end of the first switch device Q1 is connected to the controlled end of the boost thyristor Da, and the output end of the first switch device Q1 is grounded via the third resistor R3.

[0071] In this embodiment, the first switch device Q1 can be implemented by a low-level conductive switch device such as a P-type MOS tube. The first switch device Q1 can be turned on when receiving the second control signal of a low-level signal, and can pull down the controlled end level of the boost thyristor Da to the ground level when turned on, so as to control the boost thyristor Da to be turned off. When the boost thyristor Da is turned on, the second signal conversion circuit 212 can invert the step-down shutdown signal S4 of the low-level signal into a high-level signal and output it to the controlled end of the first switch device Q1, so that the first switch device Q1 can be turned off under the action of the high-level signal and the preset voltage VCC, so as to avoid the boost switch circuit 221 from affecting the normal opening of the boost thyristor Da.

[0072] Optionally, refer to Figure 5 , the step-down switch circuit 222 includes a second switch device Q2, a fourth resistor R4, a fifth resistor R5 and a sixth resistor R6;

[0073] The controlled end of the second switch device Q2 is connected to the first control signal via the fourth resistor R4, and the controlled end of the second switch device Q2 is also connected to the preset voltage VCC via the fifth resistor R5. The input end of the second switch device Q2 is connected to the controlled end of the boost thyristor Da, and the output end of the second switch device Q2 is grounded via the sixth resistor R6.

[0074] In this embodiment, the second switch device Q2 can be implemented by a low-level conduction switch device such as a P-type MOS tube. The second switch device Q2 can be turned on when receiving the first control signal of a low-level signal, and can pull down the controlled end level of the buck thyristor Db to the ground level when turned on, so as to control the buck thyristor Db to be turned off. When the buck thyristor Db is turned on, the first signal conversion circuit 211 can invert the boost shutdown signal S3 of the low-level signal into a high-level signal and output it to the controlled end of the second switch device Q2, so that the second switch device Q2 can be turned off under the action of the high-level signal and the preset voltage VCC, so as to avoid the buck switch circuit 222 from affecting the normal opening of the buck thyristor Db.

[0075] Optionally, the boost switch circuit 221 and the buck switch circuit 222 are interlocked. Specifically, the first switch device Q1 and the second switch device Q2 can be implemented by using a switch chip that integrates two switch devices and the two switch devices are interlocked. In this way, it can be ensured that the first switch device Q1 and the second switch device Q2 cannot be turned on at the same time, thereby avoiding the failure of the protection circuit 200 caused by the first switch device Q1 and the second switch device Q2 being turned on at the same time, which is conducive to further reducing the short circuit risk of the single-phase auto-coupling contactless intelligent voltage regulator.

[0076] Embodiment 2

[0077] The invention also provides a control method for a single-phase auto-coupling contactless intelligent voltage stabilizer.

[0078] Reference Figure 6 , the control method of the single-phase auto-coupling contactless intelligent voltage stabilizer includes:

[0079] S100, if a boost control signal is output, then a first control signal is generated and output to a protection circuit, so that the protection circuit controls the step-down thyristor to be turned off according to the received first control signal;

[0080] S200: If a step-down control signal is output, a second control signal is generated and output to the protection circuit, so that the protection circuit controls the boost thyristor to be turned off according to the received second control signal.

[0081] In this embodiment, the single-phase auto-coupling contactless intelligent voltage regulator may include an autotransformer, a main control circuit and a protection circuit, wherein the execution body of the control method of the single-phase auto-coupling contactless intelligent voltage regulator. The main control circuit may include a boost switch circuit and a buck switch circuit; the implementation methods of the autotransformer, the main control circuit, the boost switch circuit and the buck switch circuit and the circuit connection relationship between each other can refer to the first embodiment, and will not be repeated here. In other words, compared with the first embodiment, the difference of the second embodiment is that the main control circuit is integrated with the relevant hardware circuit or software program and algorithm for generating and outputting the first control signal and the second control signal, so that the main control circuit can directly have the output capability of the first control signal and the second control signal, thereby achieving the purpose of not having to set the first signal output circuit and the second signal output circuit, which is conducive to simplifying the circuit architecture.

[0082] Since the control method of the single-phase auto-coupling contactless intelligent voltage regulator adopts the relevant technical solution of the above-mentioned embodiment 1, it at least has all the beneficial effects brought by the technical solution of the above-mentioned embodiment 1, which will not be described one by one here.

[0083] The above descriptions are only optional embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings, or directly / indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A single-phase auto-coupling contactless intelligent voltage stabilizer, characterized in that: The single-phase auto-coupling contactless intelligent voltage stabilizer comprises: An autotransformer having an output end and N voltage regulating ends, wherein the voltage regulating end of each autotransformer is connected to the output end of the autotransformer via a voltage regulating thyristor, and wherein the first voltage regulating end is also connected to the neutral line via a step-down thyristor, and wherein the last voltage regulating end is also connected to the neutral line via a step-up thyristor, and N is greater than or equal to 2; A main control circuit, wherein the boost control terminal of the main control circuit is connected to the controlled terminal of the boost thyristor, the buck control terminal of the main control circuit is connected to the controlled terminal of the buck thyristor, and the N control terminals of the main control circuit are respectively connected one-to-one with the controlled terminals of the N voltage-regulating thyristors; the main control circuit is used to control the N voltage-regulating thyristors to be turned on in a time-sharing manner; The main control circuit is also used to output a boost start signal to the boost thyristor and output a buck stop signal to the buck thyristor; or, to output a boost stop signal to the boost thyristor and output a buck start signal to the buck thyristor; A protection circuit is connected to the boost control terminal and the buck control terminal of the main control circuit, and the controlled terminals of the boost thyristor and the buck thyristor respectively; the protection circuit is used to control the buck thyristor to turn off when receiving the boost start signal; and is used to control the boost thyristor to turn off when receiving the buck start signal; the protection circuit includes: a signal output circuit, connected to the boost control terminal and the buck control terminal of the main control circuit respectively, and used to output a first control signal from the first output terminal when receiving the boost start signal; and used to output a second control signal from the second output terminal when receiving the buck start signal; A switch circuit is connected to the controlled end of the boost thyristor, the controlled end of the buck thyristor, and the first output end and the second output end of the signal conversion circuit. The switch circuit is used to control the buck thyristor to turn off after receiving the first control signal; and to control the boost thyristor to turn off after receiving the second control signal.

2. The single-phase auto-coupling contactless intelligent voltage stabilizer according to claim 1, characterized in that: The signal output circuit comprises: a first signal conversion circuit, wherein the input end of the first signal conversion circuit is used to be connected to the boost control end of the main control circuit, and the output end of the first signal conversion circuit is the first output end of the signal output circuit; the first signal conversion circuit is used to perform level inversion on the boost start signal, and output the level-inverted boost start signal as the first control signal; A second signal conversion circuit, wherein the input end of the second signal conversion circuit is used to be connected to the buck control end of the main control circuit, and the output end of the first signal conversion circuit is the second output end of the signal output circuit; the second signal conversion circuit is used to perform level inversion on the buck start signal, and output the level-inverted buck start signal as a second control signal.

3. The single-phase auto-coupling contactless intelligent voltage stabilizer as claimed in claim 2, characterized in that: The level value of the first control signal is opposite to the level value of the boost start signal, and the level value of the second control signal is opposite to the level value of the buck start signal.

4. The single-phase auto-coupling contactless intelligent voltage stabilizer as claimed in claim 2, characterized in that: The switch circuit comprises: A boost switch circuit, connected to the controlled end of the boost thyristor and the second output end of the signal conversion circuit respectively, and the boost switch circuit is used to control the boost thyristor to turn off when receiving the second control signal; The step-down switch circuit is connected to the controlled end of the step-down thyristor and the first output end of the signal conversion circuit respectively. The step-up switch circuit is used to control the step-down thyristor to be turned off when receiving the first control signal.

5. The single-phase auto-coupling contactless intelligent voltage stabilizer as claimed in claim 4, characterized in that: The boost switch circuit includes a first switch device, a first resistor, a second resistor and a third resistor; The controlled end of the first switch device is connected to the second control signal via the first resistor, and the controlled end of the first switch device is also connected to the preset voltage via the second resistor. The input end of the first switch device is connected to the controlled end of the boost thyristor, and the output end of the first switch device is grounded via the third resistor.

6. The single-phase auto-coupling contactless intelligent voltage stabilizer as claimed in claim 4, characterized in that: The step-down switch circuit includes a second switch device, a fourth resistor, a fifth resistor and a sixth resistor; The controlled end of the second switch device is connected to the first control signal via the fourth resistor, and the controlled end of the second switch device is also connected to the preset voltage via the fifth resistor. The input end of the second switch device is connected to the controlled end of the boost thyristor, and the output end of the second switch device is grounded via the sixth resistor.

7. The single-phase auto-coupling contactless intelligent voltage stabilizer according to claim 4, characterized in that: The boost switch circuit and the buck switch circuit are interlocked.

8. A control method for a voltage stabilizer as claimed in claim 1, characterized in that: The control method comprises: If a boost control signal is output, a first control signal is generated and output to the protection circuit, so that the protection circuit controls the step-down thyristor to be turned off according to the received first control signal; If the step-down control signal is output, a second control signal is generated and output to the protection circuit, so that the protection circuit controls the step-up thyristor to be turned off according to the received second control signal.

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