A multiple hardware interlock circuit and control method for a voltage stabilizer

Abstract

The application discloses a multiple hardware interlocking circuit and control method for a voltage stabilizing device. The voltage stabilizing device comprises a main loop, a soft start loop and an ATS. The interlocking circuit comprises KA1 and KA2. The KA1 coil is connected in series with an auxiliary contact of a normal power supply of the ATS, a normally open contact connected in series with a driving power supply of the main loop. The KA2 coil is connected in series with an auxiliary contact of a standby power supply of the ATS, a normally open contact connected in series with a driving power supply of the soft start loop. When the ATS is switched to the standby power supply side, the driving power supply of the main loop is cut off. When the ATS is switched to the normal power supply side, the driving power supply of the soft start loop is cut off. The ATS switching coil loop is connected in series with the normally closed contact of KA1 and KA2. When any relay is powered, the ATS switching is prohibited. The application realizes four hardware interlocks among the main loop, the soft start loop and the ATS bypass, and is not dependent on software and has high reliability.

Description

Technical Field

[0001] This invention relates to the field of electronic voltage regulation and stabilization technology for power distribution lines, specifically to a multi-hardware interlocking circuit for voltage stabilization devices. It is applicable to various power electronic devices that require high reliability and high safety, and is particularly suitable for safety interlocking protection between the main circuit, soft-start circuit and automatic transfer switch in contactless voltage stabilization devices. Background Technology

[0002] With the large-scale integration of new energy sources into power distribution networks and the widespread use of various precision electrical equipment, problems such as grid voltage fluctuations and three-phase imbalances are becoming increasingly prominent. Contactless voltage regulators, due to their advantages such as fast response speed and no mechanical wear, are widely used in low-voltage power distribution networks, industrial production, and precision equipment power supply voltage regulation. These voltage regulators typically employ a "series compensation + tap adjustment" voltage regulation topology, using a thyristor bridge to switch the polarity and amplitude of the compensation voltage to achieve boost or buck regulation of the input voltage.

[0003] Contactless voltage regulators typically consist of a main circuit (a thyristor bridge for normal voltage regulation), a soft-start circuit (to limit inrush current), and an automatic transfer switch (ATS) (for switching to mains bypass in case of a fault). These three components pose a risk of conflict during operation: if the main circuit and soft-start circuit operate simultaneously, excessive inrush current may burn out the transformer or thyristors; if the ATS bypass and main circuit operate simultaneously, a superimposed short circuit between the regulator's main circuit and the mains power may occur; and if the ATS switches erroneously during soft-start, it may also cause a short circuit.

[0004] In existing technologies, the aforementioned interlocking functions are mostly implemented through software logic, meaning the main control unit outputs control signals after program judgment. However, software interlocking has inherent drawbacks: when the main control unit crashes, the program malfunctions, or is subjected to electromagnetic interference, the software interlock may fail, causing multiple circuits to conduct simultaneously, leading to serious equipment damage or even fires. Furthermore, a single relay interlocking scheme cannot cover all interlocking relationships between the main circuit, the soft-start circuit, and the ATS bypass, resulting in protection blind spots.

[0005] Therefore, developing a circuit capable of multiple hardware interlocks between the main circuit, soft-start circuit, and ATS bypass has become a pressing technical challenge in the field of voltage regulator safety protection technology. Summary of the Invention

[0006] The technical problem to be solved by this invention is the insufficient reliability of existing software interlocks and the existence of protection blind spots in single relay interlocks. By implementing multiple interlocks between the main circuit, soft start circuit and ATS bypass through pure hardware circuit, the safety hazards of multiple circuits being turned on at the same time are fundamentally eliminated, and the operational safety of the voltage regulator is improved. To solve the above problems, a multi-hardware interlock circuit and control method for voltage regulators are provided.

[0007] The object of this invention is achieved in the following manner: A multi-hardware interlock circuit for a voltage regulator. The voltage regulator includes a main circuit, a soft-start circuit, and an automatic transfer switch (ATS). The main circuit has a main circuit drive power supply, the soft-start circuit has a soft-start circuit drive power supply, and the ATS has a main power supply side and a backup power supply side. The multiple hardware interlock circuit includes: The first interlocking relay KA1 has its coil connected in series with the ATS common power auxiliary contact, and its normally open contact is connected in series in the power supply circuit of the main circuit drive power supply. The second interlocking relay KA2 has its coil connected in series with an ATS backup power auxiliary contact, and its normally open contact is connected in series in the power supply circuit of the soft start circuit drive power supply. The ATS common power auxiliary contact is a normally closed contact. When the ATS switches to the backup power side, the common power auxiliary contact is opened, causing the coil of the first interlock relay KA1 to be de-energized. The normally open contact of the first interlock relay KA1 is opened, cutting off the power supply to the main circuit drive power supply. The ATS backup power auxiliary contact is a normally closed contact. When the ATS switches to the normal power supply side, the backup power auxiliary contact opens, causing the coil of the second interlock relay KA2 to lose power. The normally open contact of the second interlock relay KA2 then opens, cutting off the power supply to the soft start circuit drive power supply. The switching coil power supply circuit of the ATS has a normally closed contact of the first interlocking relay KA1 and a normally closed contact of the second interlocking relay KA2 connected in series. When the coil of either the first interlocking relay KA1 or the second interlocking relay KA2 is energized, the corresponding normally closed contact opens, preventing the switching coil of the ATS from being energized and prohibiting the ATS from performing the switching action.

[0008] The main circuit includes a bridge-type bidirectional thyristor group, and the main circuit drive power supply is used to drive the bidirectional thyristors in the bridge-type bidirectional thyristor group to turn on and off. The soft-start circuit includes a soft-start bidirectional thyristor and a current-limiting resistor, and the soft-start circuit drive power supply is used to drive the soft-start bidirectional thyristor to turn on and off.

[0009] The ATS common power auxiliary contact is an auxiliary contact that is closed when the ATS is on the common power side and open when switching to the backup power side; The ATS backup power auxiliary contact is an auxiliary contact that is closed when the ATS is on the backup power side and open when switching to the normal power side.

[0010] Under normal voltage regulation, the coil of the first interlock relay KA1 is energized and its normally open contact is closed, thus connecting the main circuit drive power supply; the coil of the second interlock relay KA2 is de-energized and its normally open contact is open, thus disconnecting the soft start circuit drive power supply.

[0011] In the soft-start state, the coil of the second interlock relay KA2 is energized and its normally open contact is closed, thus connecting the power supply to the soft-start circuit drive; the coil of the first interlock relay KA1 is de-energized and its normally open contact is open, thus disconnecting the power supply to the main circuit drive.

[0012] When the ATS hard bypass is enabled, the coils of the first interlock relay KA1 and the second interlock relay KA2 are both de-energized, and their normally open contacts are both disconnected. The power supply for the main circuit drive and the power supply for the soft start circuit drive are both cut off; the ATS switches to the backup power supply side.

[0013] A multi-hardware interlock control method for a voltage regulator, applied to the multi-hardware interlock circuit, includes: when the voltage regulator is operating in normal voltage regulation mode, the coil of the first interlock relay KA1 is energized, its normally open contact closes, and the power supply of the main circuit drive power supply is connected; the coil of the second interlock relay KA2 is de-energized, its normally open contact opens, and the power supply of the soft start circuit drive power supply is cut off; the normally closed contact of the first interlock relay KA1 opens, preventing the ATS from performing a switching action; When the voltage regulator is in soft-start mode, the coil of the second interlock relay KA2 is energized, its normally open contact closes, and the power supply of the soft-start circuit drive power supply is connected; the coil of the first interlock relay KA1 is de-energized, its normally open contact opens, and the power supply of the main circuit drive power supply is cut off; the normally closed contact of the second interlock relay KA2 opens, and the ATS is prohibited from performing switching operations. When the voltage regulator needs to switch to ATS hard bypass, the coils of the first interlock relay KA1 and the second interlock relay KA2 are both de-energized, and their normally open contacts are both open, simultaneously cutting off the power supply to the main circuit drive power supply and the power supply to the soft start circuit drive power supply; the normally closed contacts of the first interlock relay KA1 and the second interlock relay KA2 are both closed, the switching coil of the ATS is energized, and the switching action is performed.

[0014] The beneficial effects of this invention are: it uses pure hardware circuitry to achieve multiple interlocks between the main circuit, soft start circuit and ATS bypass, without relying on software programs, fundamentally avoiding the risk of interlock failure caused by main control unit crashes, program malfunctions or electromagnetic interference, and its reliability is far higher than that of software interlock schemes.

[0015] It achieves four-fold hardware interlocking: main circuit and ATS bypass interlocking (ATS common power auxiliary contact + KA1), main circuit and soft start circuit interlocking (KA1 and KA2), soft start circuit and ATS bypass interlocking (ATS backup power auxiliary contact + KA2), and dual bypass interlocking (ATS switching coil and KA1 / KA2 normally closed contacts), covering all possible conflicting working scenarios with no protection blind spots.

[0016] The interlocking logic is implemented entirely through hardware connections of relay contacts, with a response speed in the millisecond range. It eliminates the need for software-based delay assessment, resulting in enhanced security.

[0017] The circuit has a simple structure, low cost, and is easy to implement, and can be widely used in various power electronic devices that require multi-circuit interlocking protection. Attached Figure Description

[0018] Figure 1 This is the electrical schematic diagram of the multiple hardware interlock circuit of the present invention; Figure 2 This is a block diagram of the overall structure of the contactless flexible voltage regulating and stabilizing device used in this invention. Detailed Implementation

[0019] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0020] It should be noted that the following detailed descriptions are exemplary and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same technical meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0021] like Figure 2 As shown, the voltage regulator used in the multi-hardware interlock circuit of this invention is specifically a contactless flexible voltage regulation regulator. This device includes a three-phase input terminal, a three-phase output terminal, a main control unit, and a voltage regulation unit. The voltage regulation unit includes three-phase voltage regulation circuits corresponding to phases A, B, and C, respectively. Each phase voltage regulation circuit has the same structure and operates independently, achieving three-phase independent regulation.

[0022] Taking the A-phase voltage regulation circuit as an example, it includes a series transformer T1, a compensation transformer T11, a tapped thyristor group, a bridge-type bidirectional thyristor group, and a soft-start circuit.

[0023] The primary side of the series transformer T1 is connected in series between the input terminal of phase A and the output terminal of phase A, and its secondary side has a first terminal A and a second terminal B.

[0024] The primary side of the compensation transformer T11 has a third terminal, point C, and its secondary side has a fourth terminal, point D. The secondary side of T11 has four taps, corresponding to four compensation voltage amplitudes: +20% / -20%, +15% / -15%, +10% / -10%, and +5% / -5%. The first tap is connected to the first terminal, point A, of the T11 secondary side via the main thyristor Q2; the second tap is connected to point A via the main thyristor Q4; the third tap is connected to point A via the main thyristor Q6; and the fourth tap is connected to point A via the main thyristor Q8. The common terminal of the T11 secondary side is connected to the second terminal, point B. Each tap also has a corresponding spare thyristor, connected in parallel with the main thyristor of the same tap: spare Q3 corresponds to Q2, spare Q5 corresponds to Q4, spare Q7 corresponds to Q6, and spare Q9 corresponds to Q8.

[0025] The bridge-type bidirectional thyristor group consists of four bidirectional thyristors Q11, Q12, Q13, and Q14 forming a cross-connection matrix: Q11 connects points A and C; Q12 connects points B and C; Q13 connects points A and D; and Q14 connects points B and D. The main control unit controls the conduction combinations of different bidirectional thyristors to allow current to flow from point C through the primary side of T11 and through magnetic coupling to the secondary side, then out at point D; or vice versa, from point D through the secondary side and through magnetic coupling to the primary side, then out at point C. This generates a positive or negative compensation voltage, which is superimposed on the secondary side of T1 to achieve boost or buck output.

[0026] The soft-start circuit consists of a soft-start bidirectional thyristor Q10 connected in series and a current-limiting resistor R1. The soft-start circuit is connected in parallel to the two ends of the bridge bidirectional thyristor group between the secondary side of the series transformer T1 and the primary and secondary sides of the compensation transformer T11.

[0027] The B-phase voltage regulating circuit includes a series transformer T2, a compensation transformer T21, and a corresponding bridge-type bidirectional thyristor group; the C-phase voltage regulating circuit includes a series transformer T3, a compensation transformer T31, and a corresponding bridge-type bidirectional thyristor group. The internal circuit structures of phases B and C are exactly the same as those of phase A.

[0028] The aforementioned bridge-type bidirectional thyristor group Q11-Q14 constitutes the main circuit and is powered by the main circuit drive power supply; the soft-start circuit Q10+R1 is powered by the soft-start circuit drive power supply. Both the main circuit drive power supply and the soft-start circuit drive power supply are low-voltage DC control power supplies, obtained by stepping down, rectifying, and stabilizing the three-phase input voltage through an auxiliary power transformer, and are electrically isolated from the three-phase main power circuit.

[0029] like Figure 1 As shown, a multi-hardware interlock circuit for the above-mentioned voltage regulator includes: The first interlocking relay KA1 has its coil connected in series with the ATS common power auxiliary contact, and its normally open contact is connected in series in the power supply circuit of the main circuit drive power supply. The second interlocking relay KA2 has its coil connected in series with an ATS backup power auxiliary contact, and its normally open contact is connected in series in the power supply circuit of the soft start circuit drive power supply. The ATS common power auxiliary contact is a normally closed contact. When the ATS switches to the backup power side, the common power auxiliary contact opens, causing the KA1 coil to lose power. The KA1 normally open contact opens, cutting off the power supply to the main circuit drive power supply. The ATS backup power auxiliary contact is a normally closed contact. When the ATS switches to the normal power supply side, the backup power auxiliary contact opens, causing the KA2 coil to lose power. The KA2 normally open contact opens, cutting off the power supply to the soft start circuit drive power supply. The ATS switching coil power supply circuit has normally closed contacts KA1 and KA2 connected in series. When either KA1 or KA2 is energized, the corresponding normally closed contact opens, preventing the ATS switching coil from being energized and prohibiting the ATS from performing the switching action.

[0030] Preferably, the secondary side of the compensation transformer T11 has four taps, corresponding to four compensation voltage amplitudes: +20% / -20%, +15% / -15%, +10% / -10%, and +5% / -5%. The first tap corresponds to the main thyristor Q2, the second tap to the main thyristor Q4, the third tap to the main thyristor Q6, and the fourth tap to the main thyristor Q8. More preferably, each tap corresponds to a spare thyristor, which is connected in parallel with the main thyristor of the same tap. The spare thyristor for the first tap is Q3, the spare thyristor for the second tap is Q5, the spare thyristor for the third tap is Q7, and the spare thyristor for the fourth tap is Q9.

[0031] Preferably, the ATS common power auxiliary contact is an auxiliary contact that is closed when the ATS is on the common power side and open when switching to the backup power side; the ATS backup power auxiliary contact is an auxiliary contact that is closed when the ATS is on the backup power side and open when switching to the common power side.

[0032] The present invention also provides a multi-hardware interlock control method for a voltage regulator, comprising: When the voltage regulator is operating in normal voltage regulation mode, the coil of KA1 is energized, its normally open contact closes, and the power supply of the main circuit drive power supply is connected; the coil of KA2 is de-energized, its normally open contact opens, and the power supply of the soft start circuit drive power supply is cut off; the normally closed contact of KA1 opens, preventing the ATS from performing switching operations.

[0033] When the voltage regulator is in soft-start mode, the coil of KA2 is energized, its normally open contact closes, and the power supply of the soft-start circuit drive power supply is connected; the coil of KA1 is de-energized, its normally open contact opens, and the power supply of the main circuit drive power supply is cut off; the normally closed contact of KA2 opens, and the ATS is prohibited from performing switching operations.

[0034] When the voltage regulator needs to switch to ATS hard bypass, the coils of KA1 and KA2 are de-energized, and their normally open contacts are opened, simultaneously cutting off the power supply to the main circuit drive power supply and the power supply to the soft start circuit drive power supply; the normally closed contacts of KA1 and KA2 are closed, the switching coil of the ATS is energized, and the switching action is performed.

[0035] Composition of multiple hardware interlock circuits: like Figure 1 As shown, the multi-hardware interlock circuit includes a first interlock relay KA1 and a second interlock relay KA2.

[0036] The KA1 coil power supply circuit has an ATS common power auxiliary contact (normally closed contact) connected in series. The ATS common power auxiliary contact is closed when the ATS is on the common power side and open when switching to the standby power side. The KA1 normally open contact is connected in series in the power supply circuit of the main circuit drive power supply and is used to control the on and off of the drive power supply of the bridge bidirectional thyristor group (Q11-Q14).

[0037] The KA2 coil power supply circuit has an ATS backup power auxiliary contact (normally closed contact) connected in series. The ATS backup power auxiliary contact is closed when the ATS is on the backup power side and open when switching to the normal power side. The normally open contact of KA2 is connected in series in the power supply circuit of the soft start circuit drive power supply and is used to control the on and off of the soft start bidirectional thyristor Q10 drive power supply.

[0038] The ATS switching coil power supply circuit has normally closed contacts of KA1 and KA2 connected in series to prevent the ATS from performing a switching action when the KA1 or KA2 coil is energized.

[0039] The ATS switching coil is powered by an operating power supply, which is obtained by isolating and stepping down the three-phase input voltage. It is used to drive the ATS to perform the switching action between the main power supply and the backup power supply.

[0040] Interlocking logic under normal voltage regulation: When the voltage regulator is operating in normal voltage regulation mode, the ATS is on the normal power supply side (the regulator output side). At this time, the ATS normal power auxiliary contact is closed, the KA1 coil is energized, the KA1 normally open contact is closed, the main circuit drive power is connected, and the bridge bidirectional thyristor group can work normally. At the same time, the ATS backup power auxiliary contact is open (because the ATS is on the normal power supply side), the KA2 coil is de-energized, the KA2 normally open contact is open, the soft start circuit drive power is cut off, and the soft start bidirectional thyristor Q10 cannot conduct, ensuring that the soft start circuit does not work simultaneously with the main circuit.

[0041] At the same time, the KA1 coil is energized, causing its normally closed contact to open, while the KA2 coil is de-energized, keeping its normally closed contact closed. The ATS switching coil power supply circuit has the normally closed contacts of KA1 and KA2 connected in series. Because the normally closed contact of KA1 is open, the ATS switching coil cannot be energized, and the ATS is prohibited from performing switching operations, ensuring that it will not be accidentally switched to the bypass under normal voltage regulation conditions.

[0042] Interlocking logic in soft-start mode: When the voltage regulator needs to perform a power-on soft start, the ATS maintains the normal power supply side. At this time, the main control unit controls the KA2 coil to be energized, the normally open contact of KA2 closes, the soft start circuit drive power is connected, and the soft start bidirectional thyristor Q10 can work normally. At the same time, the KA1 coil is de-energized (because the ATS normal power auxiliary contact is still closed, but other control contacts are connected in series in the KA1 coil circuit and are opened by the main control unit), the normally open contact of KA1 opens, the main circuit drive power is cut off, the bridge bidirectional thyristor group cannot conduct, ensuring that the main circuit does not work simultaneously with the soft start circuit.

[0043] At the same time, the KA2 coil is energized, causing its normally closed contact to open, while the KA1 coil is de-energized, keeping its normally closed contact closed. Because the normally closed contact of KA2 is open, the ATS switching coil power supply circuit cannot be energized, and the ATS is prohibited from performing switching actions, ensuring that it will not accidentally switch to the bypass during soft start.

[0044] Interlocking logic in ATS hard bypass mode: When a serious fault occurs in the voltage regulator (such as a short circuit in the main circuit, large-area breakdown of the thyristors, overheating, or input phase loss) and it needs to be switched to the ATS hard bypass, the main control unit first blocks the trigger pulses of all thyristors, and then de-energizes both the KA1 and KA2 coils.

[0045] When the KA1 coil is de-energized, its normally open contact opens, cutting off the main circuit drive power supply; when the KA2 coil is de-energized, its normally open contact opens, cutting off the soft-start circuit drive power supply. With both the main circuit and soft-start circuit drive power supplies cut off, neither thyristor can conduct.

[0046] Simultaneously, the KA1 coil loses power, causing its normally closed contact to close, and the KA2 coil also loses power, causing its normally closed contact to close. With both normally closed contacts in the ATS switching coil power supply circuit closed, the ATS switching coil is energized, and the ATS switches from the primary power supply side to the backup power supply side (mains power direct connection), with the load continuously powered by mains power. Since the drive power supplies for both the main circuit and the soft-start circuit have been disconnected, no superimposed short circuit will occur with the regulator's main circuit during the ATS bypass switching process, ensuring safe switching.

[0047] Complete protection coverage with four layers of hardware interlocks: The four-fold hardware interlocking of this invention covers all possible conflict scenarios: First layer: Main circuit and ATS bypass interlock. The ATS common power auxiliary contact is connected in series with the KA1 coil circuit. When the ATS switches to the standby power side, the common power auxiliary contact opens, the KA1 coil is de-energized, and the main circuit drive power is cut off, ensuring that the main circuit will not work in the ATS bypass state and avoiding a short circuit between the regulator's main circuit and the mains power.

[0048] Second layer: Interlocking between the main circuit and the soft-start circuit. The coil circuits of KA1 and KA2 are interconnected. When KA1 is energized (main circuit is operating), the drive power supply to the soft-start circuit is cut off; when KA2 is energized (soft start is operating), the drive power supply to the main circuit is cut off. Simultaneous operation of the main circuit and the soft-start circuit is strictly prohibited to avoid excessive inrush current that could burn out the series transformer or thyristor.

[0049] The third layer: Soft start circuit and ATS bypass interlock. The ATS backup power auxiliary contact is connected in series with the KA2 coil circuit. When the ATS switches to the normal power supply side (non-bypass state), the backup power auxiliary contact opens, the KA2 coil is de-energized, and the soft start circuit drive power is cut off. This ensures that the soft start circuit will not malfunction when the ATS is on the normal power supply side.

[0050] Fourth layer: Dual bypass interlock. The ATS switching coil power supply circuit is connected in series with normally closed contacts KA1 and KA2. When either KA1 or KA2 is engaged (i.e., either the main circuit or the soft start circuit is operating), the corresponding normally closed contact opens, the ATS switching coil cannot be energized, and the ATS is prohibited from performing switching actions, thus avoiding conflicts between bypass switching and the main circuit or soft start circuit.

[0051] Collaboration with software interlocks: The multiple hardware interlock circuit of this invention can work in conjunction with the software interlock of the main control unit to form a dual protection mechanism of "hardware as the primary and software as the secondary". During normal operation, the main control unit performs routine interlock control through software logic; when the software interlock fails due to a fault, the hardware interlock circuit can still independently complete all interlock functions to ensure equipment safety. The hardware interlock circuit does not rely on any software program, and its reliability is far higher than that of a purely software solution.

[0052] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several changes and improvements without departing from the overall concept of the present invention, and these should also be considered within the scope of protection of the present invention.

Claims

1. A multi-hardware interlock circuit for a voltage regulator, characterized in that, The voltage regulator includes a main circuit, a soft-start circuit, and an automatic transfer switch (ATS). The main circuit has a main circuit drive power supply, the soft-start circuit has a soft-start circuit drive power supply, and the automatic transfer switch (ATS) has a main power supply side and a backup power supply side. The multiple hardware interlock circuit includes: The first interlocking relay (KA1) has its coil connected in series with the ATS common power supply auxiliary contact, and its normally open contact is connected in series in the power supply circuit of the main circuit drive power supply. The second interlocking relay (KA2) has its coil connected in series with the ATS backup power auxiliary contact, and its normally open contact is connected in series in the power supply circuit of the soft start circuit drive power supply. The ATS common power auxiliary contact is a normally closed contact. When the ATS switches to the backup power side, the common power auxiliary contact is opened, causing the coil of the first interlock relay (KA1) to be de-energized. The normally open contact of the first interlock relay (KA1) is opened, cutting off the power supply to the main circuit drive power supply. The ATS backup power auxiliary contact is a normally closed contact. When the ATS switches to the normal power supply side, the backup power auxiliary contact opens, causing the coil of the second interlock relay (KA2) to lose power. The normally open contact of the second interlock relay (KA2) then opens, cutting off the power supply to the soft start circuit drive power supply. The switching coil power supply circuit of the ATS has the normally closed contact of the first interlocking relay (KA1) and the normally closed contact of the second interlocking relay (KA2) connected in series. When the coil of either the first interlocking relay (KA1) or the second interlocking relay (KA2) is energized, the corresponding normally closed contact opens, preventing the switching coil of the ATS from being energized and prohibiting the ATS from performing the switching action.

2. The multi-hardware interlock circuit for a voltage regulator according to claim 1, characterized in that, The main circuit includes a bridge-type bidirectional thyristor group, and the main circuit drive power supply is used to drive the bidirectional thyristors in the bridge-type bidirectional thyristor group to turn on and off. The soft-start circuit includes a soft-start bidirectional thyristor and a current-limiting resistor, and the soft-start circuit drive power supply is used to drive the soft-start bidirectional thyristor to turn on and off.

3. The multi-hardware interlock circuit for a voltage regulator according to claim 1, characterized in that, The ATS common power auxiliary contact is an auxiliary contact that is closed when the ATS is on the common power side and open when switching to the backup power side; The ATS backup power auxiliary contact is an auxiliary contact that is closed when the ATS is on the backup power side and open when switching to the normal power side.

4. The multi-hardware interlock circuit for a voltage regulator according to claim 1, characterized in that, Under normal voltage regulation conditions, the coil of the first interlock relay (KA1) is energized and its normally open contact is closed, thus connecting the main circuit drive power supply; the coil of the second interlock relay (KA2) is de-energized and its normally open contact is open, thus disconnecting the soft start circuit drive power supply.

5. The multi-hardware interlock circuit for a voltage regulator according to claim 1, characterized in that, In the soft-start state, the coil of the second interlock relay (KA2) is energized and its normally open contact is closed, thus connecting the power supply to the soft-start circuit drive; the coil of the first interlock relay (KA1) is de-energized and its normally open contact is open, thus disconnecting the power supply to the main circuit drive.

6. The multi-hardware interlock circuit for a voltage regulator according to claim 1, characterized in that, When the ATS hard bypass is enabled, the coils of the first interlock relay (KA1) and the second interlock relay (KA2) are both de-energized, and their normally open contacts are both disconnected. The power supply for the main circuit drive and the power supply for the soft start circuit drive are both cut off; the ATS switches to the backup power supply side.

7. A method for controlling multiple hardware interlocks in a voltage regulator, applied to the multiple hardware interlock circuit described in any one of claims 1 to 6, characterized in that, include: When the voltage regulator is operating in normal voltage regulation mode, the coil of the first interlock relay (KA1) is energized, its normally open contact closes, and the power supply of the main circuit drive power supply is connected; the coil of the second interlock relay (KA2) is de-energized, its normally open contact opens, and the power supply of the soft start circuit drive power supply is cut off; the normally closed contact of the first interlock relay (KA1) opens, preventing the ATS from performing switching operations. When the voltage regulator is in soft-start mode, the coil of the second interlock relay (KA2) is energized, its normally open contact closes, and the power supply of the soft-start circuit drive power supply is connected; the coil of the first interlock relay (KA1) is de-energized, its normally open contact opens, and the power supply of the main circuit drive power supply is cut off; the normally closed contact of the second interlock relay (KA2) opens, preventing the ATS from performing switching operations; When the voltage regulator needs to switch to ATS hard bypass, the coils of the first interlock relay (KA1) and the second interlock relay (KA2) are both de-energized, and their normally open contacts are both open, simultaneously cutting off the power supply to the main circuit drive power supply and the power supply to the soft start circuit drive power supply; the normally closed contacts of the first interlock relay (KA1) and the second interlock relay (KA2) are both closed, the switching coil of the ATS is energized, and the switching action is performed.

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