A compensating contactless mains voltage stabilizing device

Abstract

The present invention relates to a compensated contactless mains voltage stabilizing device, comprising an autotransformer, a compensating transformer, a controller, a first thyristor compensator, a second thyristor compensator and a third thyristor compensator, wherein the autotransformer comprises three winding connection ends, and the compensating transformer comprises a plurality of first primary winding ends, a second primary winding end and two secondary winding ends; the first winding connection end is electrically connected to the live wire, the last winding connection end is electrically connected to the neutral wire, the three winding connection ends are electrically connected to the third thyristor compensator through the second thyristor compensator, the second primary winding end is electrically connected to the live wire and the neutral wire respectively through the first thyristor compensator, each first primary winding end is electrically connected to the third thyristor compensator; the two secondary winding ends are connected in series to the live wire. The present invention realizes mains voltage stabilization by controlling the on-off of each thyristor, which is a contactless compensation voltage stabilization method, and solves the defects in the existing mains voltage stabilization technology based on relays.

Description

Technical Field

[0001] The invention relates to the technical field of mains power management, and in particular to a compensated contactless mains power voltage stabilizing device. Background Art

[0002] Mains power is the alternating current (AC) that we usually use. In actual mains power supply systems, mains power fluctuations often occur due to long power supply lines or unstable loads on power supply lines. Mains power fluctuations will accelerate the aging of electrical equipment, reduce their lifespan, and in severe cases, burn out electrical equipment. They will also reduce the capacity of power transmission and transformation equipment and the charging power of power supply lines. Some equipment (such as medical equipment) has extremely high requirements for voltage accuracy. Therefore, it is crucial to reduce mains power fluctuations and achieve voltage stabilization.

[0003] In the existing voltage stabilization technology for AC power fluctuations, relays are mainly used to change the taps of the transformer or carbon brushes to move the contact points. Although this method achieves the purpose of voltage stabilization by changing the input-output turns ratio of the transformer, it is a voltage stabilization method with contacts and the 220V AC power voltage is directly applied to the circuit. Therefore, there are a series of problems such as low efficiency, poor anti-interference ability, slow response speed, and high harmonic components of output voltage and current. At the same time, the voltage stabilization device corresponding to this method is usually large in size, and is extremely inconvenient to use and install. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a compensated contactless AC power voltage stabilizing device in view of the deficiencies of the above-mentioned prior art. Based on the control of the on and off of each thyristor compensator by the controller, contactless compensated AC power voltage stabilization is realized, which has high efficiency, strong anti-interference ability, fast response speed, does not generate harmonic components of the output voltage circuit, and can be made very small in size.

[0005] The technical solution of the present invention to solve the above technical problems is as follows:

[0006] A compensated contactless mains voltage stabilizing device, comprising an autotransformer and a compensating transformer, wherein the autotransformer comprises three winding connection ends arranged in sequence, the compensating transformer comprises a plurality of first primary winding ends and a second primary winding end arranged in sequence, and the compensating transformer further comprises two secondary winding ends arranged in sequence;

[0007] The compensated contactless mains voltage stabilizing device further comprises a controller, a first thyristor compensator for controlling the direction of the compensation voltage, and a second thyristor compensator and a third thyristor compensator for controlling the magnitude of the compensation voltage; the controller is electrically connected to the three-phase mains, the first thyristor compensator, the second thyristor compensator and the third thyristor compensator respectively;

[0008] The first winding connection end of the autotransformer is electrically connected to the live wire of any phase of the three-phase mains, the last winding connection end of the autotransformer is electrically connected to the neutral wire of any phase of the three-phase mains, and the three winding connection ends of the autotransformer are also electrically connected to one end of the third thyristor compensator through the second thyristor compensator;

[0009] The second primary winding end of the compensation transformer is electrically connected to the live wire and the neutral wire of any phase of the three-phase mains through the first thyristor compensator, and each first primary winding end of the compensation transformer is electrically connected to the other end of the third thyristor compensator; the two secondary winding ends of the compensation transformer are connected in series to the live wire of any phase of the three-phase mains.

[0010] On the basis of the above technical solution, the present invention has the following improvements:

[0011] Further: the controller includes a power conversion circuit and an MCU;

[0012] The MCU is electrically connected to the three-phase mains through the power conversion circuit, and the MCU is also electrically connected to the first thyristor compensator, the second thyristor compensator and the third thyristor compensator respectively.

[0013] Further: the first thyristor compensator includes a first thyristor control circuit and a second thyristor control circuit;

[0014] The input end of the first thyristor control circuit is electrically connected to the live wire of any phase of the three-phase mains power, the input end of the second thyristor control circuit is electrically connected to the neutral wire of any phase of the three-phase mains power, the output end of the first thyristor control circuit and the output end of the second thyristor control circuit are both electrically connected to the second primary winding end of the compensation transformer, and the control end of the first thyristor control circuit and the control end of the second thyristor control circuit are both electrically connected to the controller.

[0015] Further: the second thyristor compensator includes three third thyristor control circuits;

[0016] The input ends of the three third thyristor control circuits are electrically connected to the three winding connection ends of the autotransformer in a one-to-one correspondence, the output end of each of the third thyristor control circuits is electrically connected to one end of the third thyristor compensator, and the control end of each of the third thyristor control circuits is electrically connected to the controller.

[0017] Further: the third thyristor compensator includes a plurality of fourth thyristor control circuits;

[0018] The number of the fourth thyristor control circuits is the same as the number of the first primary winding ends of the compensation transformer, and the output ends of all the fourth thyristor control circuits are electrically connected to all the first primary winding ends in a one-to-one correspondence, the input end of each of the fourth thyristor control circuits is electrically connected to the output ends of the three third thyristor control circuits, and the control end of each of the fourth thyristor control circuits is electrically connected to the controller.

[0019] Further: the number of the first primary winding ends of the compensation transformer and the number of the fourth thyristor control circuits are both 5.

[0020] Further: the first thyristor control circuit, the second thyristor control circuit, each third thyristor control circuit and each fourth thyristor control circuit include a thyristor, a trigger transformer U22, a transistor Q3, a first diode D14, a second diode D15, a third diode D16, a first resistor R97, a second resistor R98, a third resistor R93, a fourth resistor R94, a fifth resistor R90, a varistor VR10 and a capacitor C64;

[0021] The base of the first transistor Q3 is electrically connected to the controller through the first resistor R97, the base of the first transistor Q3 is also grounded through the second resistor R98, the emitter of the first transistor Q3 is grounded, the collector of the first transistor Q3 is electrically connected to the primary same-name end of the trigger transformer U22 through the first diode D14 and the third resistor R93 in sequence, and the collector of the first transistor Q3 is also directly electrically connected to the primary non-same-name end of the trigger transformer U22; the secondary same-name end of the trigger transformer U22 is electrically connected to the control electrode of the thyristor through the second diode D15, and the secondary non-same-name end of the trigger transformer U22 is electrically connected to the The anode of the thyristor is electrically connected to the cathode of the thyristor, the cathode of the third diode D16 and one end of the fourth resistor R94 are both connected to the common end of the first diode D15 and the control electrode of the thyristor, the anode of the third diode D16 and the other end of the fourth resistor R94 are both connected to the common end of the secondary non-same-name end of the trigger transformer U22 and the anode of the thyristor; one end of the fifth resistor R90 and one end of the varistor VR10 are both electrically connected to the cathode of the thyristor, the other end of the fifth resistor R90 is electrically connected to the anode of the thyristor through the capacitor C64, and the other end of the varistor VR10 is also electrically connected to the anode of the thyristor.

[0022] Further: in the first thyristor control circuit, the anode of the thyristor, the capacitor C64 and the other end of the varistor VR10 are also electrically connected to the live wire of any phase of the three-phase mains, and one end of the fifth resistor R90 and one end of the varistor VR10 are also electrically connected to the second primary winding end of the compensation transformer;

[0023] In the second thyristor control circuit, the anode of the thyristor, the capacitor C64 and the other end of the varistor VR10 are also electrically connected to the neutral line of any phase of the three-phase mains, and one end of the fifth resistor R90 and one end of the varistor VR10 are also electrically connected to the second primary winding end of the compensation transformer.

[0024] Further: in each of the third thyristor control circuits, the anode of the thyristor, the capacitor C64 and the other end of the varistor VR10 are also electrically connected to the corresponding winding connection ends in the autotransformer, and one end of the fifth resistor R90 and one end of the varistor VR10 are also electrically connected to one end of the third thyristor controller.

[0025] Further: in each of the fourth thyristor control circuits, the anode of the thyristor, the capacitor C64 and the other end of the varistor VR10 are also electrically connected to the output ends of the three third thyristor control circuits, and one end of the fifth resistor R90 and one end of the varistor VR10 are also electrically connected to the corresponding first primary winding end in the compensation transformer.

[0026] Further: the compensated contactless mains voltage stabilizing device further comprises a first interlocking circuit, a second interlocking circuit and a third interlocking circuit;

[0027] The controller is electrically connected to the control end of the first thyristor control circuit and the control end of the second thyristor control circuit respectively through the first interlocking circuit, and the controller is also electrically connected to the control end of each of the third thyristor control circuits respectively through the second interlocking circuit, and the controller is also electrically connected to the control end of each of the fourth thyristor control circuits respectively through the third interlocking circuit.

[0028] Further: the first interlock circuit, the second interlock circuit and the third interlock circuit each include a 74HC138 decoder.

[0029] The beneficial effects of the present invention are as follows: the first thyristor compensator, the second thyristor compensator and the third thyristor controller are all thyristor-based compensators, each of which contains a thyristor. By controlling the on-off of the thyristor in the first thyristor compensator through the controller, the direction of the output voltage compensated by the compensation transformer can be adjusted, that is, the increase or decrease of the compensation voltage can be adjusted; by controlling the on-off of the thyristor in the second thyristor compensator and the third thyristor compensator through the controller, the transformation ratio of the compensation transformer can be changed, and then the numerical value of the output voltage compensated by the compensation transformer can be adjusted, and finally the compensated mains voltage stabilization can be realized;

[0030] The compensated contactless AC voltage stabilizing device in the present invention realizes AC voltage stabilization based on the on-off control of each thyristor by a controller. The 220V AC voltage will not be directly applied to the circuit. It is a contactless compensation voltage stabilizing method, which can effectively improve the efficiency and output voltage stabilization accuracy. The action time is zero, the response speed is fast, and when the voltage is switched at zero point, the voltage does not fluctuate, which can effectively avoid the influence of voltage fluctuation on the load and has strong anti-interference ability. The compensated voltage is reduced in proportion to the input voltage waveform, and will not change the input voltage waveform, but only change the amplitude of the input voltage, so that no harmonic components of the output voltage circuit will appear. A variety of different compensation voltage value combinations can be combined by turning on and off each thyristor to realize multi-speed voltage regulation. At the same time, due to the compensated voltage stabilizing device, the output power can be effectively reduced, so that the cross-sectional area of ​​the transformer core required by the voltage stabilizing device is greatly reduced, thereby effectively reducing the volume of the entire voltage stabilizing device and improving the portability of use and installation. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a structural schematic diagram of a compensation type contactless mains voltage stabilizing device in an embodiment of the present invention;

[0032] Figure 2 It is a structural schematic diagram of another compensation type contactless mains voltage stabilizing device in an embodiment of the present invention;

[0033] Figure 3 2 is a schematic diagram of the structure of a third thyristor control circuit in an embodiment of the present invention;

[0034] Figure 4 It is a structural schematic diagram of another compensation type contactless mains voltage stabilizing device in an embodiment of the present invention;

[0035] Figure 5 The chip structure diagram of the decoder of the 74HC138 model in the embodiment of the present invention;

[0036] Figure 6 Schematic diagram of the structure of the third interlocking circuit in an embodiment of the present invention. DETAILED DESCRIPTION

[0037] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0038] The present invention will be described below in conjunction with the accompanying drawings.

[0039] Example, such as Figure 1 As shown, a compensated contactless mains voltage stabilizing device comprises an autotransformer and a compensating transformer, wherein the autotransformer comprises three winding connection ends arranged in sequence, the compensating transformer comprises a plurality of first primary winding ends and a second primary winding end arranged in sequence, and the compensating transformer further comprises two secondary winding ends arranged in sequence;

[0040] The compensated contactless mains voltage stabilizing device further comprises a controller, a first thyristor compensator for controlling the direction of the compensation voltage, and a second thyristor compensator and a third thyristor compensator for controlling the magnitude of the compensation voltage; the controller is electrically connected to the three-phase mains, the first thyristor compensator, the second thyristor compensator and the third thyristor compensator respectively;

[0041] The first winding connection end of the autotransformer is electrically connected to the live wire of any phase of the three-phase mains, the last winding connection end of the autotransformer is electrically connected to the neutral wire of any phase of the three-phase mains, and the three winding connection ends of the autotransformer are also electrically connected to one end of the third thyristor compensator through the second thyristor compensator;

[0042] The second primary winding end of the compensation transformer is electrically connected to the live wire and the neutral wire of any phase of the three-phase mains through the first thyristor compensator, and each first primary winding end of the compensation transformer is electrically connected to the other end of the third thyristor compensator; the two secondary winding ends of the compensation transformer are connected in series to the live wire of any phase of the three-phase mains.

[0043] The working principle of the compensated contactless mains voltage stabilizing device of this embodiment is as follows:

[0044] The first thyristor compensator, the second thyristor compensator and the third thyristor controller are all thyristor-based compensators, each of which contains a thyristor. By controlling the on-off of the thyristor in the first thyristor compensator through the controller, the direction of the output voltage compensated by the compensation transformer can be adjusted, that is, the increase or decrease of the compensation voltage can be adjusted; by controlling the on-off of the thyristor in the second thyristor compensator and the third thyristor compensator through the controller, the transformation ratio of the compensation transformer can be changed, and then the numerical value of the output voltage compensated by the compensation transformer can be adjusted, thereby finally realizing compensated AC voltage stabilization.

[0045] The compensated contactless AC voltage stabilizing device of the present embodiment realizes AC voltage stabilization based on the on-off control of each thyristor by the controller. The 220V AC voltage will not be directly applied to the circuit. It is a contactless compensation voltage stabilizing method, which can effectively improve the efficiency and output voltage stabilization accuracy. The action time is zero and the response speed is fast. When the voltage is switched at zero point, there is no voltage fluctuation, which can effectively avoid the influence of voltage fluctuation on the load and has strong anti-interference ability. The compensated voltage is reduced in proportion to the input voltage waveform, and will not change the input voltage waveform, but only change the amplitude of the input voltage, so that no harmonic components of the output voltage circuit will appear. A variety of different compensation voltage value combinations can be combined by turning on and off each thyristor to realize multi-speed voltage regulation. At the same time, since the compensated voltage stabilizing device can effectively reduce the output power, the cross-sectional area of ​​the transformer core required for the voltage stabilizing device is greatly reduced, thereby effectively reducing the volume of the entire voltage stabilizing device and improving the portability of use and installation.

[0046] Figure 1 T1 represents the compensation transformer, T2 represents the autotransformer, UI represents the three-phase mains input voltage, U O It is the output voltage after three-phase AC power compensation and voltage stabilization.

[0047] Preferably, the controller includes a power conversion circuit and an MCU;

[0048] The MCU is electrically connected to the three-phase mains through the power conversion circuit, and the MCU is also electrically connected to the first thyristor compensator, the second thyristor compensator and the third thyristor compensator respectively.

[0049] The MCU is connected to the three-phase mains power through the power conversion circuit, which can achieve the working voltage required for the MCU operation, so that the MCU can control the on and off of each thyristor, and then change the input-output turns ratio of the compensation transformer to achieve compensated contactless voltage stabilization.

[0050] Specifically, the power conversion circuit may include a rectifier circuit and a buck circuit to respectively realize AC / DC conversion and buck, and may adopt conventional designs in the prior art; the MCU may select existing conventional models according to actual conditions, which are not listed here.

[0051] Preferably, if Figure 2 As shown, the first thyristor compensator includes a first thyristor control circuit and a second thyristor control circuit;

[0052] The input end of the first thyristor control circuit is electrically connected to the live wire of any phase of the three-phase mains power, the input end of the second thyristor control circuit is electrically connected to the neutral wire of any phase of the three-phase mains power, the output end of the first thyristor control circuit and the output end of the second thyristor control circuit are both electrically connected to the second primary winding end of the compensation transformer, and the control end of the first thyristor control circuit and the control end of the second thyristor control circuit are both electrically connected to the controller.

[0053] Since the control end of the first thyristor control circuit and the control end of the second thyristor control circuit are electrically connected to the controller respectively, they can receive the instructions of the controller respectively, and then control the on and off of the corresponding thyristors respectively; and the input end of the first thyristor control circuit is connected to the live wire of any phase, and the input end of the second thyristor control circuit is connected to the neutral wire of any phase, and the connected voltages are in opposite directions, so that when the corresponding thyristors are turned on, the voltage directions of the compensation voltages are just opposite, thereby effectively realizing the direction adjustment of the compensation voltage; for example, when the thyristor in the first thyristor control circuit is turned on, the compensation voltage increases, and when the thyristor in the second thyristor control circuit is turned on, the compensation voltage decreases.

[0054] Preferably, if Figure 2 As shown, the second thyristor compensator includes three third thyristor control circuits;

[0055] The input ends of the three third thyristor control circuits are electrically connected to the three winding connection ends of the autotransformer in a one-to-one correspondence, the output end of each of the third thyristor control circuits is electrically connected to one end of the third thyristor compensator, and the control end of each of the third thyristor control circuits is electrically connected to the MCU.

[0056] Through the second thyristor compensator of the above structure, it is convenient to adjust the effective number of turns of the autotransformer output based on the autotransformer, and then combine with the third thyristor compensator to adjust the input-output turns ratio of the compensation transformer, and obtain a variety of different combinations of input-output turns ratios, thereby effectively realizing multi-level adjustment of the numerical value of the compensation voltage and improving the voltage stabilization accuracy.

[0057] Preferably, if Figure 2 As shown, the third thyristor compensator includes a plurality of fourth thyristor control circuits;

[0058] The number of the fourth thyristor control circuits is the same as the number of the first primary winding ends of the compensation transformer, and the output ends of all the fourth thyristor control circuits are electrically connected to all the first primary winding ends in a one-to-one correspondence, the input end of each of the fourth thyristor control circuits is electrically connected to the output ends of the three third thyristor control circuits, and the control end of each of the fourth thyristor control circuits is electrically connected to the MCU.

[0059] By means of the above-mentioned multiple fourth thyristor control circuits electrically connected one-to-one with all the first primary winding ends of the compensation transformer, the three winding connection ends of the autotransformer can be combined to realize multi-level adjustment of the numerical value of the compensation voltage and improve the voltage stabilization accuracy.

[0060] Specifically, Figure 2 As shown, the number of the first primary winding ends of the compensation transformer and the number of the fourth thyristor control circuits are both 5.

[0061] Preferably, if Figure 3 As shown, the first thyristor control circuit, the second thyristor control circuit, each third thyristor control circuit and each fourth thyristor control circuit include a thyristor, a trigger transformer U22, a transistor Q3, a first diode D14, a second diode D15, a third diode D16, a first resistor R97, a second resistor R98, a third resistor R93, a fourth resistor R94, a fifth resistor R90, a varistor VR10 and a capacitor C64;

[0062] The base of the first transistor Q3 is electrically connected to the controller through the first resistor R97, the base of the first transistor Q3 is also grounded through the second resistor R98, the emitter of the first transistor Q3 is grounded, the collector of the first transistor Q3 is electrically connected to the primary same-name end of the trigger transformer U22 through the first diode D14 and the third resistor R93 in sequence, and the collector of the first transistor Q3 is also directly electrically connected to the primary non-same-name end of the trigger transformer U22; the secondary same-name end of the trigger transformer U22 is electrically connected to the control electrode of the thyristor through the second diode D15, and the secondary non-same-name end of the trigger transformer U22 is electrically connected to the The anode of the thyristor is electrically connected to the cathode of the thyristor, the cathode of the third diode D16 and one end of the fourth resistor R94 are both connected to the common end of the first diode D15 and the control electrode of the thyristor, the anode of the third diode D16 and the other end of the fourth resistor R94 are both connected to the common end of the secondary non-same-name end of the trigger transformer U22 and the anode of the thyristor; one end of the fifth resistor R90 and one end of the varistor VR10 are both electrically connected to the cathode of the thyristor, the other end of the fifth resistor R90 is electrically connected to the anode of the thyristor through the capacitor C64, and the other end of the varistor VR10 is also electrically connected to the anode of the thyristor.

[0063] Due to the thyristor control circuits in the above circuit structure, the on-off control of the corresponding thyristors can be realized with a fast response speed. Compared with the traditional voltage stabilization method based on relays, when the voltage is switched at zero point, there is no voltage fluctuation, which can effectively avoid the influence of voltage fluctuations on the load and has strong anti-interference ability.

[0064] Specifically, in the first thyristor control circuit, the anode of the thyristor, the capacitor C64 and the other end of the varistor VR10 are also electrically connected to the live wire of any phase of the three-phase mains, and one end of the fifth resistor R90 and one end of the varistor VR10 are also electrically connected to the second primary winding end of the compensation transformer;

[0065] In the second thyristor control circuit, the anode of the thyristor, the capacitor C64 and the other end of the varistor VR10 are also electrically connected to the neutral line of any phase of the three-phase mains, and one end of the fifth resistor R90 and one end of the varistor VR10 are also electrically connected to the second primary winding end of the compensation transformer.

[0066] By means of the first thyristor control circuit and the second thyristor control circuit, the direction of the compensation voltage can be adjusted efficiently and accurately.

[0067] It should be noted that Figure 3 Only the complete circuit diagram of one of the third thyristor control circuits is listed. Figure 3 D1 is the thyristor in the third thyristor control circuit, Ua represents the live wire of any phase, and the circuit diagrams of other thyristor control circuits are similar to this. The connection relationship between the components between the thyristor and the MCU in each thyristor control circuit is the same. It is only necessary to connect the anode and cathode of the corresponding thyristor in each thyristor control circuit according to the connection method introduced above, and the specific circuit diagram will not be repeated here.

[0068] Specifically, Figure 3 As shown, in each of the third thyristor control circuits, the anode of the thyristor, the capacitor C64 and the other end of the varistor VR10 are also electrically connected to the corresponding winding connection ends in the autotransformer, and one end of the fifth resistor R90 and one end of the varistor VR10 are also electrically connected to one end of the third thyristor controller.

[0069] Specifically, in each of the fourth thyristor control circuits, the anode of the thyristor, the capacitor C64 and the other end of the varistor VR10 are also electrically connected to the output ends of the three third thyristor control circuits, and one end of the fifth resistor R90 and one end of the varistor VR10 are also electrically connected to the corresponding first primary winding end of the compensation transformer.

[0070] By combining the third thyristor control circuits and the fourth thyristor control circuits of the above structure, the numerical value of the compensation voltage can be adjusted efficiently and accurately.

[0071] In addition, in each thyristor control circuit, D15, D16, and R94 play a shaping role, and R93 and D14 play a freewheeling role. The specifications or models of each electronic component are as follows: Figure 3 shown.

[0072] Preferably, if Figure 4 As shown, the compensated contactless mains voltage stabilizing device further includes a first interlocking circuit, a second interlocking circuit and a third interlocking circuit;

[0073] The controller is electrically connected to the control end of the first thyristor control circuit and the control end of the second thyristor control circuit respectively through the first interlocking circuit, and the controller is also electrically connected to the control end of each of the third thyristor control circuits respectively through the second interlocking circuit, and the controller is also electrically connected to the control end of each of the fourth thyristor control circuits respectively through the third interlocking circuit.

[0074] The controller is electrically connected to the first thyristor control circuit and the second thyristor control circuit respectively through the first interlocking circuit, and can realize interlocking between the first thyristor control circuit and the second thyristor control circuit based on the first interlocking circuit, so as to avoid the thyristors in the first thyristor control circuit and the thyristors in the second thyristor control circuit being turned on at the same time; similarly, the second interlocking circuit can avoid the simultaneous conduction between the third thyristor control circuits, and the third interlocking circuit can avoid the simultaneous conduction between the fourth thyristor control circuits; it is convenient to realize the adjustment of the compensation voltage direction and the compensation voltage value, and can also effectively avoid AC short circuit, thereby protecting the entire voltage stabilizing device.

[0075] Specifically, the first interlock circuit, the second interlock circuit and the third interlock circuit each include a 74HC138 decoder.

[0076] like Figure 4As shown, D4 and D5 represent the first thyristor control circuit and the second thyristor control circuit respectively, and the primary coil corresponding to the second primary winding end of the compensation transformer T2 connected thereto is represented by N5; the autotransformer T1 has three winding connection ends, which correspond to two coils, represented by N7 and N8 respectively, and the corresponding three third thyristor control circuits are represented by D1, D2 and D3 respectively; the compensation transformer T2 has five first primary winding ends, which correspond to four primary coils, represented by N1, N2, N3 and N4 respectively, and the five fourth thyristor control circuits corresponding to the five first primary winding ends are represented by D7, D8, D9, D10 and D11 respectively, and the compensation transformer T2 has two secondary winding ends, which correspond to one secondary coil, represented by N6.

[0077] Figure 5 The chip structure diagram of the 74HC138 decoder is given. Figure 6 The structural diagram of the third interlocking circuit for controlling the interlocking of the five fourth thyristor control circuits (i.e., controlling D7, D8, D9, D10 and D11) is given. Figure 6 In the figure, CS_4_MCU, CS_5_MCU, and CS_6_MCU are all output signals provided by the MCU. Only one of the output Y0-Y7 of 74HC138 can output a high level, forming an interlocking mechanism, thereby realizing the interlocking between D7, D8, D9, D10, and D11. The second interlocking circuit between D1, D2, and D3 and the first interlocking circuit between D4 and D5 are consistent with the above. Figure 6 To keep the same, it is only necessary to replace the output pins of the corresponding 74HC138. The interlock mechanism of the 74HC138 decoder is preset in this embodiment as shown in Table 1.

[0078]

[0079] Specifically, the three-phase mains power output power of this embodiment is 1100 kVA (i.e. 1100 kW), and the core cross-sectional area S1 of the compensation transformer T1 is pre-set to be 636.4 cm 2 , frequency 50Hz, core magnetic induction intensity 0.9T, effective voltage 220V, maximum compensation voltage 40V, transformer efficiency 0.9 and empirical coefficient 1.35 and other basic parameters, and based on the theoretical knowledge of transformers, the maximum number of turns of each coil is calculated as N1=48 turns, N2=5 turns, N3=4 turns, N4=5 turns, N5=18 turns and N6=4 turns respectively; similarly, the core cross-sectional area S2 of the autotransformer T2 is pre-set to 670.8cm 2, frequency 50Hz, core magnetic induction intensity 0.9T, effective voltage 220V, maximum compensation voltage 40V, transformer efficiency 0.9 and empirical coefficient 1.35 and other basic parameters, the maximum number of turns of each coil is calculated to be N7=9 turns and N8=9 turns respectively.

[0080] In this embodiment, according to Figure 4 The complete structure of the AC voltage stabilizing device shown in the figure, Figure 3 The thyristor control circuits shown in the figure and the interlocking mechanism shown in Table 1 can obtain the 16-level compensation voltage adjustment shown in Table 2. In Table 2, "+" represents an increase in the compensation voltage, and "-" represents a decrease in the compensation voltage.

[0081]

[0082] The number of turns in Table 2 above is explained as follows:

[0083] When the gear is "+5V", the effective turns of T2 are N7 and N8, that is, T2 outputs UI / 2, and the effective turns of the primary side of T1 are N1+N2+N3+N4+N5;

[0084] When the gear is "+10V", the effective turns of T2 is 0, and the effective turns of the primary side of T1 is N1+N2+N3+N4+N5;

[0085] When the gear is "+15V", the effective turns of T2 are N7 and N8, that is, T2 outputs UI / 2, and the effective turns of the primary side of T1 are N3+N4+N5;

[0086] When the gear is "+20V", the effective turns of T2 are N7 and N8, that is, T2 outputs UI / 2, and the effective turns of the primary side of T1 is N5;

[0087] When the gear is "+25V", the effective turns of T2 is 0, and the effective turns of the primary side of T1 is N2+N3+N4+N5;

[0088] When the gear is "+30V", the effective turns of T2 is 0, and the effective turns of the primary side of T1 is N3+N4+N5;

[0089] When the gear is "+35V", the effective turns of T2 are 0, and the effective turns of the primary side of T1 are N4+N5;

[0090] When the gear is "+40V", the effective turns of T2 is 0, and the effective turns of the primary side of T1 is N5;

[0091] When the gear is "-5V", the effective turns of T2 are N7 and N8, that is, T2 outputs UI / 2, and the effective turns of the primary side of T1 are N1+N2+N3+N4+N5;

[0092] When the gear is "-10V", the effective turns of T2 is 0, and the effective turns of the primary side of T1 is N1+N2+N3+N4+N5;

[0093] When the gear is "-15V", the effective turns of T2 are N7 and N8, that is, T2 outputs UI / 2, and the effective turns of the primary side of T1 are N3+N4+N5;

[0094] When the gear is "-20V", the effective turns of T2 are N7 and N8, that is, T2 outputs UI / 2, and the effective turns of the primary side of T1 is N5;

[0095] When the gear is "-25V", the effective turns of T2 is 0, and the effective turns of the primary side of T1 is N2+N3+N4+N5;

[0096] When the gear is "-30V", the effective turns of T2 are 0, and the effective turns of the primary side of T1 are N3+N4+N5;

[0097] When the gear is "-35V", the effective turns of T2 are 0, and the effective turns of the primary side of T1 are N4+N5;

[0098] When the gear is "-40V", the effective turns of T2 is 0, and the effective turns of the primary side of T1 is N5.

[0099] The mains voltage stabilizing device capable of achieving 16-speed adjustment in this embodiment has the following beneficial effects:

[0100] (1) Output voltage regulation accuracy: ±3.5V. The voltage fluctuation of each output voltage level is 5V, that is, the minimum output voltage regulation accuracy is ±2.5V. If a 2V range fluctuation is reserved, the voltage regulation accuracy can be ±3.5V.

[0101] (2) 16 levels of voltage regulation, the input voltage is AC175-265V and the voltage regulation accuracy can be achieved.

[0102] (3) The efficiency can reach 99%. When the gear is "+40V" or "-40V", the efficiency is the lowest, the efficiency of the compensation part is 95%, and the overall efficiency is = 99.05%.

[0103] (4) Switching at zero voltage with 0MS. The AC power is a sinusoidal waveform. When switching at zero voltage, the thyristor has a zero action time because it is an electron tube. That is, when switching at zero voltage, there is no voltage fluctuation, which can avoid the impact of voltage fluctuation on the load.

[0104] (5) The overall transformer is smaller. Since this device is a compensation type, the maximum power is only 40 / 220 = 1 / 5.5 of the output power, and the cross-sectional area of ​​the device is only 1 / 2.34 of that of the traditional device.

[0105] (6) Does not affect the waveform of the input voltage. Since this device is a compensation type, the compensation voltage is proportionally reduced from the input voltage waveform. The compensation voltage is added to the output voltage, and the zero point coincides. Therefore, the input voltage waveform is not changed, only the amplitude is changed.

[0106] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A compensated contactless mains voltage stabilizing device, comprising an autotransformer and a compensating transformer, characterized in that: The autotransformer includes three winding connection ends arranged in sequence, the compensating transformer includes a plurality of first primary winding ends and a second primary winding end arranged in sequence, and the compensating transformer also includes two secondary winding ends arranged in sequence; The compensated contactless mains voltage stabilizing device further comprises a controller, a first thyristor compensator for controlling the direction of the compensation voltage, and a second thyristor compensator and a third thyristor compensator for controlling the magnitude of the compensation voltage; the controller is electrically connected to the three-phase mains, the first thyristor compensator, the second thyristor compensator and the third thyristor compensator respectively; The first winding connection end of the autotransformer is electrically connected to the live wire of any phase of the three-phase mains, the last winding connection end of the autotransformer is electrically connected to the neutral wire of any phase of the three-phase mains, and the three winding connection ends of the autotransformer are also electrically connected to one end of the third thyristor compensator through the second thyristor compensator; The second primary winding end of the compensation transformer is electrically connected to the live wire and the neutral wire of any phase of the three-phase mains through the first thyristor compensator, and each first primary winding end of the compensation transformer is electrically connected to the other end of the third thyristor compensator; the two secondary winding ends of the compensation transformer are connected in series to the live wire of any phase of the three-phase mains; The first thyristor compensator includes a first thyristor control circuit and a second thyristor control circuit; The input end of the first thyristor control circuit is electrically connected to the live wire of any phase of the three-phase mains power, the input end of the second thyristor control circuit is electrically connected to the neutral wire of any phase of the three-phase mains power, the output end of the first thyristor control circuit and the output end of the second thyristor control circuit are both electrically connected to the second primary winding end of the compensation transformer, and the control end of the first thyristor control circuit and the control end of the second thyristor control circuit are both electrically connected to the controller; The second thyristor compensator includes three third thyristor control circuits; The input ends of the three third thyristor control circuits are electrically connected to the three winding connection ends of the autotransformer in a one-to-one correspondence, the output end of each of the third thyristor control circuits is electrically connected to one end of the third thyristor compensator, and the control end of each of the third thyristor control circuits is electrically connected to the controller; The third thyristor compensator includes a plurality of fourth thyristor control circuits; The number of the fourth thyristor control circuits is the same as the number of the first primary winding ends of the compensation transformer, and the output ends of all the fourth thyristor control circuits are electrically connected to all the first primary winding ends in a one-to-one correspondence, the input end of each of the fourth thyristor control circuits is electrically connected to the output ends of the three third thyristor control circuits, and the control end of each of the fourth thyristor control circuits is electrically connected to the controller; The first thyristor control circuit, the second thyristor control circuit, each third thyristor control circuit and each fourth thyristor control circuit include a thyristor, a trigger transformer U22, a first transistor Q3, a first diode D14, a second diode D15, a third diode D16, a first resistor R97, a second resistor R98, a third resistor R93, a fourth resistor R94, a fifth resistor R90, a varistor VR10 and a capacitor C64; The base of the first transistor Q3 is electrically connected to the controller through the first resistor R97, the base of the first transistor Q3 is also grounded through the second resistor R98, the emitter of the first transistor Q3 is grounded, the collector of the first transistor Q3 is electrically connected to the primary same-name end of the trigger transformer U22 through the first diode D14 and the third resistor R93 in sequence, and the collector of the first transistor Q3 is also directly electrically connected to the primary non-same-name end of the trigger transformer U22; the secondary same-name end of the trigger transformer U22 is electrically connected to the control electrode of the thyristor through the second diode D15, and the secondary non-same-name end of the trigger transformer U22 is electrically connected to the The anode of the thyristor is electrically connected to the cathode of the thyristor, the cathode of the third diode D16 and one end of the fourth resistor R94 are both connected to the common end of the first diode D15 and the control electrode of the thyristor, the anode of the third diode D16 and the other end of the fourth resistor R94 are both connected to the common end of the secondary non-same-name end of the trigger transformer U22 and the anode of the thyristor; one end of the fifth resistor R90 and one end of the varistor VR10 are both electrically connected to the cathode of the thyristor, the other end of the fifth resistor R90 is electrically connected to the anode of the thyristor through the capacitor C64, and the other end of the varistor VR10 is also electrically connected to the anode of the thyristor; In the first thyristor control circuit, the anode of the thyristor, the capacitor C64 and the other end of the varistor VR10 are also electrically connected to the live wire of any phase of the three-phase mains, and one end of the fifth resistor R90 and one end of the varistor VR10 are also electrically connected to the second primary winding end of the compensation transformer; In the second thyristor control circuit, the anode of the thyristor, the capacitor C64 and the other end of the varistor VR10 are also electrically connected to the neutral line of any phase of the three-phase mains, and one end of the fifth resistor R90 and one end of the varistor VR10 are also electrically connected to the second primary winding end of the compensation transformer; In each of the third thyristor control circuits, the anode of the thyristor, the capacitor C64 and the other end of the varistor VR10 are also electrically connected to the corresponding winding connection ends in the autotransformer, and one end of the fifth resistor R90 and one end of the varistor VR10 are also electrically connected to one end of the third thyristor control circuit.

2. The compensated contactless mains voltage stabilizing device according to claim 1, characterized in that: In each of the fourth thyristor control circuits, the anode of the thyristor, the capacitor C64 and the other end of the varistor VR10 are also electrically connected to the output ends of the three third thyristor control circuits, and one end of the fifth resistor R90 and one end of the varistor VR10 are also electrically connected to the corresponding first primary winding end of the compensation transformer.

3. The compensated contactless mains voltage stabilizing device according to claim 1 or 2, characterized in that: The compensated contactless mains voltage stabilizing device further comprises a first interlocking circuit, a second interlocking circuit and a third interlocking circuit; The controller is electrically connected to the control end of the first thyristor control circuit and the control end of the second thyristor control circuit respectively through the first interlocking circuit, and the controller is also electrically connected to the control end of each of the third thyristor control circuits respectively through the second interlocking circuit, and the controller is also electrically connected to the control end of each of the fourth thyristor control circuits respectively through the third interlocking circuit.

4. The compensated contactless mains voltage stabilizing device according to claim 3, characterized in that: The first interlock circuit, the second interlock circuit and the third interlock circuit each include a 74HC138 decoder.

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