Voltage regulating device, control method and system for a transformer

Abstract

The application provides a voltage regulating device, a control method and a system of a transformer, comprising: a low-voltage winding, a high-voltage winding, an adjustable winding assembly, an IGBT switching mechanism and a controller; the low-voltage winding and the high-voltage winding are coupled; one end of the adjustable winding assembly is connected with the high-voltage winding, and the other end of the adjustable winding assembly is connected with the IGBT switching mechanism; the controller is connected with the adjustable winding assembly and the IGBT switching mechanism, and the controller is used for controlling the input and output of the adjustable winding assembly and the opening and closing of the IGBT switching mechanism. Through the adjustable winding assembly and the IGBT switching mechanism, the application realizes the quick switching of the voltage regulating winding in the adjustable winding assembly, the switching speed is faster than that of the static switch, the voltage regulation without inrush current is realized, the generation of electric arc in the conventional switching process is eliminated, and the speed and efficiency of the voltage regulation are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of voltage regulation of distribution transformers, and in particular to a voltage regulating device, a control method and a system for a transformer. Background Art

[0002] In power systems, when grid voltage or load changes, the transformer's output voltage will also change. When the change exceeds the permissible range, it will affect the production and life of power users. To ensure that the transformer output voltage is within the permissible range, automatic voltage regulation technology has begun to be used. That is, when the output voltage exceeds the permissible value, the number of turns of the primary and secondary windings of the distribution transformer is adjusted by selecting different winding taps, thereby changing the distribution transformer's ratio and ensuring that the voltage at the load end remains within a reasonable range.

[0003] Current automatic voltage regulation technology for distribution transformers faces two challenges: First, on-load tap changers (OLTs) are typically used. Most existing OLTs are mechanical switches, which not only generate arcs during switching, but also wear and tear on the mechanical contacts, leading to a degradation of transformer oil quality and the need for frequent oil filtering, limiting their application. The few that utilize power electronics for voltage regulation have complex voltage regulation topologies, numerous auxiliary devices, and electronic switches connected in series during operation, increasing energy consumption and reducing reliability. Second, conventional distribution transformers with tap adjustment have low regulation accuracy, approximately 2.5% of the rated voltage. With both positive and negative secondary winding taps, the regulation range of the distribution transformer is approximately -5% to 5% of its rated voltage. However, in practical power systems, industrial loads often experience significant daytime peak and valley variations, resulting in significant voltage fluctuations at the load end, often exceeding the voltage range regulated by conventional tap adjustment methods for distribution transformers. Summary of the Invention

[0004] To address the problems existing in existing automatic voltage regulation technology for distribution transformers, the present invention provides a transformer voltage regulation device, control method, and system. The present invention enables rapid switching of the transformer's voltage regulating windings and continuous load regulation, resolving the issue of continuous fluctuations in the transformer's input voltage.

[0005] The technical solution provided by the present invention is: a voltage regulating device for a transformer, comprising:

[0006] Low voltage winding, high voltage winding, adjustable winding assembly, IGBT switching mechanism and controller;

[0007] The low voltage winding and the high voltage winding are coupled;

[0008] One end of the adjustable winding assembly is connected to the high-voltage winding, and the other end of the adjustable winding assembly is connected to the IGBT switching mechanism;

[0009] The controller is connected to the adjustable winding assembly and the IGBT switching mechanism, and is used to control the switching on and off of the adjustable winding assembly and the switching on and off of the IGBT switching mechanism.

[0010] Preferably, the adjustable winding assembly comprises: a voltage regulating winding, a first voltage regulating switch group and a second voltage regulating switch group, wherein the first voltage regulating switch group and the second voltage regulating switch group respectively comprise a plurality of voltage regulating switches;

[0011] The IGBT switching mechanism includes: a first arc extinguishing component and a second arc extinguishing component;

[0012] One end of the voltage regulating switch in the first voltage regulating switch group is connected to one end of the first arc extinguishing component, and the connection point is point A;

[0013] One end of the voltage regulating switch in the second voltage regulating switch group is connected to one end of the second arc extinguishing component, and the connection point is point B;

[0014] The other end of the first arc-extinguishing assembly is connected to the other end of the second arc-extinguishing assembly, and the connection point is point C;

[0015] The other ends of all the voltage regulating switches are respectively connected to the turns of the voltage regulating winding.

[0016] Preferably, the first arc-extinguishing component includes a first IGBT and a first arc-extinguishing switch connected in parallel;

[0017] The second arc-extinguishing component includes a second IGBT and a second arc-extinguishing switch connected in parallel.

[0018] Preferably, the IGBT switching mechanism further comprises: a first high-voltage filter capacitor and a second high-voltage filter capacitor;

[0019] One end of the first high-voltage filter capacitor is connected to point A, one end of the second high-voltage filter capacitor is connected to point B, and the other end of the first high-voltage filter capacitor and the other end of the second high-voltage filter capacitor are connected to point C.

[0020] Preferably, when the transformer is working, any voltage regulating switch and the second arc extinguishing switch in the second voltage regulating switch group are closed.

[0021] Preferably, the voltage regulating switch is a magnetic latching relay.

[0022] Preferably, the arc extinguishing switch is a magnetic latching relay.

[0023] Preferably, the voltage regulating device further comprises: a measuring winding;

[0024] The measuring winding is connected to the controller, and is used to measure the voltage value of the low-voltage winding and send the voltage value to the controller;

[0025] The controller is further configured to select a trigger strategy based on the voltage value.

[0026] Based on the same inventive concept, the present invention provides a control method based on the voltage regulating device, comprising:

[0027] The controller calculates the voltage regulation requirement of the adjustable winding assembly based on the difference between the measured voltage value of the low-voltage winding and the rated voltage, and generates the voltage regulation logic;

[0028] Based on the voltage regulation logic, the controller outputs a corresponding control signal in a time sequence to control the opening and closing of the IGBT switching mechanism and the switching of the adjustable winding component into and out of the high-voltage winding.

[0029] Preferably, the controller outputs a corresponding control signal in a time sequence based on the voltage regulation logic to control the opening and closing of the IGBT switching mechanism and the switching of the adjustable winding component into and out of the high-voltage winding, including:

[0030] When the first arc suppression switch is closed, the voltage is regulated by operating the first voltage regulating switch group, and based on the trigger strategy sent by the controller, the voltage regulating switch corresponding to the voltage regulating winding to be connected enters the pre-connection state, the first IGBT is closed, the first arc suppression switch is opened, and power is supplied through the first IGBT;

[0031] After phase locking, the first IGBT is turned off before the voltage passes through zero, and the second IGBT is closed when the voltage passes through zero. After switching, the second arc suppression switch is closed and the second IGBT is disconnected, so that the voltage regulating winding to be connected is connected in series with the high-voltage winding.

[0032] Preferably, the controller outputs a corresponding control signal in a time sequence based on the voltage regulation logic to control the opening and closing of the IGBT switching mechanism and the switching of the adjustable winding component into and out of the high-voltage winding, and further includes:

[0033] When the second arc suppression switch is closed, the voltage is regulated by operating the second voltage regulating switch group. Based on the trigger strategy sent by the controller, the voltage regulating switch corresponding to the voltage regulating winding to be connected enters the pre-connection state, the second IGBT is closed, the second arc suppression switch is opened, and power is supplied through the second IGBT;

[0034] After phase locking, the second IGBT is turned off before the voltage passes through zero, and the first IGBT is closed when the voltage passes through zero. After switching, the first arc suppression switch is closed and the first IGBT is disconnected, so that the voltage regulating winding to be connected is connected in series with the high-voltage winding.

[0035] Preferably, the zero-crossing point is determined according to the current of the high-voltage winding.

[0036] Based on the same inventive concept, the present invention also provides a control system based on the voltage regulating device, comprising:

[0037] Measurement module, operation control module and trigger output module;

[0038] The measuring module is used to measure the voltage value of the low-voltage winding;

[0039] The operation control module is used for the controller to calculate the voltage regulation requirement of the adjustable winding assembly based on the difference between the measured voltage value of the low-voltage winding and the rated voltage, and generate the voltage regulation logic;

[0040] The trigger output module is used for the controller to output the corresponding control signal in a time sequence based on the voltage regulation logic, to control the opening and closing of the IGBT switching mechanism, and the switching on and off of the high-voltage winding of the adjustable winding component.

[0041] Preferably, the trigger output module includes:

[0042] a first triggering unit, configured to regulate voltage by operating the first voltage-regulating switch group when the first arc-extinguishing switch is closed, and to cause the voltage-regulating switch corresponding to the voltage-regulating winding to be connected to enter a pre-connection state based on a triggering strategy sent by the controller, thereby closing the first IGBT, disconnecting the first arc-extinguishing switch, and supplying power through the first IGBT;

[0043] Cooperating with the first trigger unit, it is used to close the first IGBT before the voltage passes through zero after phase locking, close the second IGBT when the voltage passes through zero, close the second arc suppression switch after switching, and disconnect the second IGBT, so that the voltage regulating winding to be connected is connected in series with the high-voltage winding.

[0044] Preferably, the trigger output module includes:

[0045] a second triggering unit, configured to regulate voltage by operating the second voltage regulating switch group when the second arc suppression switch is closed, and to cause the voltage regulating switch corresponding to the voltage regulating winding to be connected to enter a pre-connection state based on the triggering strategy sent by the controller, close the second IGBT, disconnect the second arc suppression switch, and supply power through the second IGBT;

[0046] Cooperating with the second trigger unit, it is used to close the second IGBT before the voltage passes through zero after phase locking, close the first IGBT when the voltage passes through zero, close the first arc suppression switch after switching, and disconnect the first IGBT, so that the voltage regulating winding to be connected is connected in series with the high-voltage winding.

[0047] Preferably, the control system further includes: a power supply module;

[0048] The power supply module is used to provide electrical energy to the control system.

[0049] Compared with the prior art, the present invention has the following beneficial effects:

[0050] The technical solution provided by the present invention comprises a low-voltage winding, a high-voltage winding, an adjustable winding assembly, an IGBT switching mechanism, and a controller; the low-voltage winding and the high-voltage winding are coupled; one end of the adjustable winding assembly is connected to the high-voltage winding, and the other end of the adjustable winding assembly is connected to the IGBT switching mechanism; the controller is connected to the adjustable winding assembly and the IGBT switching mechanism, and is used to control the switching of the adjustable winding assembly and the IGBT switching mechanism. Through the adjustable winding assembly and the IGBT switching mechanism, rapid switching of the voltage regulating winding in the adjustable winding assembly is achieved, with a switching speed faster than a static switch, achieving inrush-free voltage regulation, eliminating arcing during conventional switching, and improving the speed and efficiency of voltage regulation.

[0051] The technical solution provided by the present invention can realize rapid switching of the transformer voltage regulating winding and perform continuous load regulation, thereby solving the problem caused by continuous fluctuation of the transformer output voltage.

[0052] The technical solution provided by the present invention adopts a high-voltage IGBT as a transition tap changer, and the IGBT is a fully controlled component, which is more perfect than a thyristor in control.

[0053] The technical solution provided by the present invention automatically detects and controls voltage by measuring windings, thereby realizing automatic voltage regulation control.

[0054] The technical solution provided by the present invention does not require any electronic switch to be connected after voltage regulation is completed, thereby improving reliability, reducing losses, and achieving maximum energy saving. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 A schematic structural diagram of the voltage regulating device provided by the present invention;

[0056] Figure 2 Schematic diagram of a control system according to an embodiment of the present invention;

[0057] Figure 3 A schematic structural diagram of the switching mechanism provided by the present invention;

[0058] Figure 4 This is a flow chart of a control method for a voltage regulating device in a transformer according to an embodiment of the present invention. DETAILED DESCRIPTION

[0059] In order to better understand the present invention, the present invention is further described below with reference to the accompanying drawings and examples.

[0060] Example 1:

[0061] like Figure 1The voltage regulating device shown includes: a low voltage winding, a high voltage winding, an adjustable winding assembly, an IGBT switching mechanism and a controller;

[0062] The low voltage winding and the high voltage winding are coupled;

[0063] One end of the adjustable winding assembly is connected to the high-voltage winding, and the other end of the adjustable winding assembly is connected to the IGBT switching mechanism;

[0064] The controller is connected to the adjustable winding assembly and the IGBT switching mechanism, and is used to control the switching on and off of the adjustable winding assembly and the switching on and off of the IGBT switching mechanism.

[0065] Wherein, the adjustable winding assembly includes: a voltage regulating winding, a first voltage regulating switch group and a second voltage regulating switch group, wherein the first voltage regulating switch group and the second voltage regulating switch group respectively include a plurality of voltage regulating switches;

[0066] The IGBT switching mechanism includes: a first arc extinguishing component and a second arc extinguishing component;

[0067] One end of the voltage regulating switch in the first voltage regulating switch group is connected to one end of the first arc extinguishing component, and the connection point is point A;

[0068] One end of the voltage regulating switch in the second voltage regulating switch group is connected to one end of the second arc extinguishing component, and the connection point is point B;

[0069] The other end of the first arc-extinguishing assembly is connected to the other end of the second arc-extinguishing assembly, and the connection point is point C;

[0070] The other ends of all the voltage regulating switches are respectively connected to the turns of the voltage regulating winding.

[0071] Furthermore, the first arc-extinguishing component includes a first IGBT and a first arc-extinguishing switch connected in parallel;

[0072] The second arc-extinguishing component includes a second IGBT and a second arc-extinguishing switch connected in parallel.

[0073] Furthermore, the IGBT switching mechanism further includes: a first high-voltage filter capacitor and a second high-voltage filter capacitor;

[0074] One end of the first high-voltage filter capacitor is connected to point A, one end of the second high-voltage filter capacitor is connected to point B, and the other end of the first high-voltage filter capacitor and the other end of the second high-voltage filter capacitor are connected to point C.

[0075] The voltage regulating device provided in this embodiment includes: an adjustable winding assembly consisting of 8 voltage regulating windings and 9 voltage regulating switches, an IGBT switching mechanism consisting of 2 IGBTs (Insulated Gate Bipolar Transistors) and a magnetic latching relay, a high-voltage winding, a low-voltage winding, and a measuring winding.

[0076] Among them, the IGBT switching mechanism includes two arc extinguishing components, each arc extinguishing component includes a high-voltage IGBT and a magnetic latching relay, and each arc extinguishing component is connected in parallel with a high-voltage filter capacitor. The IGBT switching mechanism plays a transition role in the switching process, and the long-term power supply is passed through the magnetic latching relay.

[0077] The power supply module and the measuring winding are the same independent winding, and the number of turns is determined according to the output voltage. This winding is mainly used to measure the voltage of the low-voltage winding and the power demand of the control circuit.

[0078] The voltage regulating device provided in this embodiment realizes arc-free on-load voltage regulation and rapid voltage regulation. According to the actual voltage fluctuation of the distribution network where the distribution transformer is located, the output voltage of the low-voltage side is controlled within a constant range. By controlling the nine voltage regulating switches, the specified voltage regulating winding can be controlled to connect to the high-voltage winding, and the equivalent number of turns of the high-voltage winding can be changed, thereby stabilizing the voltage output on the low-voltage side of the distribution transformer over a large range.

[0079] The voltage regulating device provided in this embodiment realizes the rapid switching on and off of the voltage regulating winding through the transition process of the IGBT switching mechanism, thereby eliminating the generation of arcs during the conversion process. At the same time, under normal circumstances, the IGBT switching mechanism is out of operation, thereby reducing losses and improving reliability.

[0080] The controller in this embodiment may adopt an existing ARM V6 processor, an MCS-51 single chip microcomputer or a TMS320C54 digital signal processing (DSP) chip.

[0081] The magnetic latching relay can utilize the HFE10 relay.

[0082] Example 2:

[0083] (1) Figure 1 As shown, the distribution transformer includes a high-voltage winding, a low-voltage winding, a measuring winding, an adjustable winding assembly consisting of 8 voltage regulating windings and 9 voltage regulating switches, an IGBT switching mechanism, and a controller.

[0084] The IGBT switching mechanism includes two arc extinguishing components, each of which includes a high-voltage IGBT and a magnetic latching relay.

[0085] Each voltage regulating switch is connected to the turns of the voltage regulating winding.

[0086] (2) This embodiment takes the voltage regulating winding 1 as an example to illustrate the connection method of the voltage regulating winding. The voltage regulating winding 1 is connected to K6 and K2 in the voltage regulating switch. When K2 is closed and K6 is disconnected, the voltage regulating winding 1 is connected; when K6 is closed and K2 is disconnected, the voltage regulating winding is not connected.

[0087] 1) Voltage regulating winding description:

[0088] a. When the transformer is in power supply state, only one switch among K1 to K9 is closed;

[0089] b. When the transformer is in voltage regulation state, one of K6, K7, K1, K8, and K9 switches is closed, and one of K2, K3, K4, and K5 switches is closed;

[0090] (3) In this embodiment, by controlling the on / off state of the voltage regulating switch, the voltage regulating winding is connected in series with the high-voltage winding as required, thereby changing the equivalent number of turns of the high-voltage winding. On the other hand, the generation of arcs during the voltage regulation process can be eliminated by the action of the IGBT switching mechanism.

[0091] Each time the voltage regulating winding is connected in series with the high voltage winding, the IGBT is activated first, and then the arc suppression switch connected in parallel with the IGBT is activated.

[0092] by Figure 1 The IGBT fast switching mechanism and two voltage regulating windings shown in the figure are used as an example to illustrate the voltage regulation process of the transformer:

[0093] 1) The first way to switch the voltage regulation mode of the voltage regulation winding:

[0094] Determine the voltage regulating winding connection state based on the sampled voltage of the measuring winding, and operate switches K2-K5 in the left voltage regulating switch array to put the voltage regulating winding into the pre-connection state in an appropriate manner;

[0095] Then the electronic switch G2 is closed, the normally closed switch K11 is opened, and power is supplied through the electronic switch G2.

[0096] After phase locking, the electronic switch G2 is closed before the voltage passes through zero, and the electronic switch G1 is closed at zero point for zero-delay switching. After switching, K10 is closed, and then the electronic switch G1 is disconnected. The voltage regulating winding is connected in series to the main circuit according to the preset method, and the winding voltage regulation is completed.

[0097] 2) The second way to switch the voltage regulation winding to the voltage regulation mode:

[0098] Determine the access state of the voltage regulating winding according to the sampled voltage of the measuring winding, and operate switches K6, K7, K1, K8, and K9 in the right voltage regulating switch array to make the voltage regulating winding enter the pre-access state in an appropriate manner;

[0099] First close the electronic switch G1, disconnect K10, disconnect the electronic switch G1 before crossing the zero point, close the electronic switch G2 when crossing the zero point, close K11, and then disconnect the electronic switch G2. The corresponding voltage regulating winding is connected in series to the main circuit according to the preset method, the voltage regulation mode exits, and the voltage regulation is completed.

[0100] (4) When the voltage regulating winding is connected, when K1 is closed, the transformer is in the rated voltage working state. When K6, K2, K7, and K3 are closed, the transformer is in the step-up mode. When K4, K8, K5, and K9 are closed, the transformer is in the step-down mode.

[0101] K10 is used in conjunction with the left voltage regulating switches K2 to K5, and K11 is used in conjunction with the right voltage regulating switches K6, K7, K1, K8, and K9.

[0102] (5) Figure 2 As shown in the structural diagram of the control system, the control system mainly includes a power supply module, a measurement module, an operation control module, and a trigger output module.

[0103] The power supply module is a coil with a separate winding that provides power to the entire control system;

[0104] The measuring module is used to measure the output voltage of the low-voltage side of the transformer and provide a reference for the voltage regulation of the voltage regulating transformer. The rated voltage of the low-voltage side is usually used as the adjustment target. In this embodiment, the power supply module and the measuring module can share a coil.

[0105] The calculation control module calculates the number of winding turns that should be adjusted on the high-voltage side based on the difference between the current low-voltage side voltage and the rated voltage provided by the measurement module, and generates the expected voltage regulation winding state matrix and voltage regulation logic;

[0106] The trigger output module outputs the corresponding control signal in a time sequence according to the voltage regulation logic generated by the operation control module, turns on or off the relevant switches, and realizes that the voltage regulation winding is connected in series to the high voltage side according to the voltage regulation logic, thereby achieving the purpose of voltage regulation.

[0107] Furthermore, the trigger output module includes:

[0108] a first triggering unit, configured to regulate voltage by operating the first voltage-regulating switch group when the first arc-extinguishing switch is closed, and to cause the voltage-regulating switch corresponding to the voltage-regulating winding to be connected to enter a pre-connection state based on a triggering strategy sent by the controller, thereby closing the first IGBT, disconnecting the first arc-extinguishing switch, and supplying power through the first IGBT;

[0109] Cooperating with the first trigger unit, it is used to close the first IGBT before the voltage passes through zero after phase locking, close the second IGBT when the voltage passes through zero, close the second arc suppression switch after switching, and disconnect the second IGBT, so that the voltage regulating winding to be connected is connected in series with the high-voltage winding.

[0110] Furthermore, the trigger output module includes:

[0111] a second triggering unit, configured to regulate voltage by operating the second voltage regulating switch group when the second arc suppression switch is closed, and to cause the voltage regulating switch corresponding to the voltage regulating winding to be connected to enter a pre-connection state based on the triggering strategy sent by the controller, close the second IGBT, disconnect the second arc suppression switch, and supply power through the second IGBT;

[0112] Cooperating with the second trigger unit, it is used to close the second IGBT before the voltage passes through zero after phase locking, close the first IGBT when the voltage passes through zero, close the first arc suppression switch after switching, and disconnect the first IGBT, so that the voltage regulating winding to be connected is connected in series with the high-voltage winding.

[0113] (6) Figure 3 As shown, the IGBT switching mechanism includes: high-voltage filter capacitors (C1, C2), IGBT and magnetic latching relay K. The IGBT is a type without parallel diode, and the magnetic latching relay K is connected in parallel with the IGBT.

[0114] In a voltage regulating switch, a high-voltage filter capacitor protects the IGBT from overvoltage when the IGBT switching mechanism is in operation.

[0115] The switching mechanism switches at the overcurrent zero point based on the high-voltage side current sampling.

[0116] (7) Figure 1 The high and low voltage windings and voltage regulating winding shown are only the voltage regulating connection diagrams of one phase of the three-phase winding of the distribution transformer in actual application. The connection methods of the other two phases are the same. Figure 1 same.

[0117] (8) This embodiment also provides a method for controlling the access state of the voltage regulating winding in the transformer by using a voltage regulating switch, thereby adjusting the output voltage of the transformer. The method provides a method for fast arc-free switching when the voltage regulating winding changes its access state and an operation method of the voltage regulating switch.

[0118] From this implementation case, we can see that by adjusting the voltage regulating switch, the voltage regulating winding can be smoothly and arc-freely connected in series with the high-voltage winding, thereby providing a method for wide-range and high-precision on-load voltage regulation of the transformer.

[0119] Example 3

[0120] Based on the same inventive concept, the present invention also provides a control method based on the voltage regulating device, such as Figure 4As shown, the control method of the voltage regulating device includes:

[0121] Step S1: The controller calculates the voltage regulation requirement of the adjustable winding assembly based on the difference between the measured voltage value of the low-voltage winding and the rated voltage, and generates the voltage regulation logic;

[0122] Step S2: Based on the voltage regulation logic, the controller outputs a corresponding control signal in a time sequence to control the opening and closing of the IGBT switching mechanism and the switching on and off of the adjustable winding component to the high-voltage winding.

[0123] Step S2: Based on the voltage regulation logic, the controller outputs a corresponding control signal in a time sequence to control the opening and closing of the IGBT switching mechanism and the switching of the adjustable winding assembly into and out of the high-voltage winding, specifically including:

[0124] When the first arc suppression switch is closed, the voltage is regulated by operating the first voltage regulating switch group, and based on the trigger strategy sent by the controller, the voltage regulating switch corresponding to the voltage regulating winding to be connected enters the pre-connection state, the first IGBT is closed, the first arc suppression switch is opened, and power is supplied through the first IGBT;

[0125] After phase locking, the first IGBT is turned off before the voltage passes through zero, and the second IGBT is closed when the voltage passes through zero. After switching, the second arc suppression switch is closed and the second IGBT is disconnected, so that the voltage regulating winding to be connected is connected in series with the high-voltage winding.

[0126] Furthermore, when the second arc suppression switch is closed, the voltage is regulated by operating the second voltage regulating switch group, and based on the trigger strategy sent by the controller, the voltage regulating switch corresponding to the voltage regulating winding to be connected enters the pre-connection state, the second IGBT is closed, the second arc suppression switch is opened, and power is supplied through the second IGBT;

[0127] After phase locking, the second IGBT is turned off before the voltage passes through zero, and the first IGBT is closed when the voltage passes through zero. After switching, the first arc suppression switch is closed and the first IGBT is disconnected, so that the voltage regulating winding to be connected is connected in series with the high-voltage winding.

[0128] In an embodiment, the zero-crossing point is determined according to the current of the high-voltage winding.

[0129] The above are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are included in the scope of the claims of the present invention to be approved.

Claims

1. A voltage regulating device for a transformer, characterized in that: include: Low voltage winding, high voltage winding, adjustable winding assembly, IGBT switching mechanism and controller; The low voltage winding and the high voltage winding are coupled; One end of the adjustable winding assembly is connected to the high-voltage winding, and the other end of the adjustable winding assembly is connected to the IGBT switching mechanism; The controller is connected to the adjustable winding assembly and the IGBT switching mechanism, and is used to control the switching on and off of the adjustable winding assembly and the switching on and off of the IGBT switching mechanism; The adjustable winding assembly includes: a voltage regulating winding, a first voltage regulating switch group and a second voltage regulating switch group, wherein the first voltage regulating switch group and the second voltage regulating switch group respectively include a plurality of voltage regulating switches, and the voltage regulating switches are magnetic latching relays; The IGBT switching mechanism includes: a first arc extinguishing component and a second arc extinguishing component; One end of the voltage regulating switch in the first voltage regulating switch group is connected to one end of the first arc extinguishing component, and the connection point is point A; One end of the voltage regulating switch in the second voltage regulating switch group is connected to one end of the second arc extinguishing component, and the connection point is point B; The other end of the first arc-extinguishing assembly is connected to the other end of the second arc-extinguishing assembly, and the connection point is point C; The other ends of all the voltage regulating switches are respectively connected to the turns of the voltage regulating winding.

2. The voltage regulating device according to claim 1, wherein: The first arc-extinguishing component includes a first IGBT and a first arc-extinguishing switch connected in parallel; The second arc-extinguishing component includes a second IGBT and a second arc-extinguishing switch connected in parallel.

3. The voltage regulating device according to claim 2, wherein: The IGBT switching mechanism further includes: a first high-voltage filter capacitor and a second high-voltage filter capacitor; One end of the first high-voltage filter capacitor is connected to point A, one end of the second high-voltage filter capacitor is connected to point B, and the other end of the first high-voltage filter capacitor and the other end of the second high-voltage filter capacitor are connected to point C.

4. The voltage regulating device according to claim 2, wherein: When the transformer is working, any voltage regulating switch and the second arc suppression switch in the second voltage regulating switch group are closed.

5. The voltage regulating device according to claim 2 or 4, characterized in that: The arc extinguishing switch is a magnetic latching relay.

6. The voltage regulating device according to claim 1, wherein: The voltage regulating device further includes: a measuring winding; The measuring winding is connected to the controller, and is used to measure the voltage value of the low-voltage winding and send the voltage value to the controller; The controller is further configured to select a trigger strategy based on the voltage value.

7. A control method based on the voltage regulating device, used for the device according to claim 2, characterized in that: include: The controller calculates the voltage regulation requirement of the adjustable winding assembly based on the difference between the measured voltage value of the low-voltage winding and the rated voltage, and generates the voltage regulation logic; Based on the voltage regulation logic, the controller outputs a corresponding control signal in a time sequence to control the opening and closing of the IGBT switching mechanism and the switching of the adjustable winding component into and out of the high-voltage winding; The controller outputs a corresponding control signal in a time sequence based on the voltage regulation logic to control the opening and closing of the IGBT switching mechanism and the switching of the adjustable winding component into and out of the high-voltage winding, including: When the first arc suppression switch is closed, the voltage is regulated by operating the first voltage regulating switch group. Based on the trigger strategy sent by the controller, the voltage regulating switch corresponding to the voltage regulating winding to be connected enters the pre-connection state, the first IGBT is closed, the first arc suppression switch is disconnected, and power is supplied through the first IGBT. The voltage regulating switch is a magnetic latching relay. After phase locking, the first IGBT is turned off before the voltage crosses zero, and the second IGBT is turned on when the voltage crosses zero. After switching, the second arc suppression switch is closed and the second IGBT is turned off, so that the voltage regulating winding to be connected is connected in series with the high-voltage winding. When the second arc suppression switch is closed, the voltage is regulated by operating the second voltage regulating switch group. Based on the trigger strategy sent by the controller, the voltage regulating switch corresponding to the voltage regulating winding to be connected enters the pre-connection state, the second IGBT is closed, the second arc suppression switch is opened, and power is supplied through the second IGBT; After phase locking, the second IGBT is turned off before the voltage crosses zero, and the first IGBT is closed when the voltage crosses zero. After switching, the first arc suppression switch is closed and the first IGBT is disconnected, so that the voltage regulating winding to be connected is connected in series with the high-voltage winding.

8. The control method according to claim 7, wherein: The zero-crossing point is determined according to the current of the high-voltage winding.

9. A control system based on the voltage regulating device, used in the device according to claim 2, characterized in that: include: Measurement module, operation control module and trigger output module; The measuring module is used to measure the voltage value of the low-voltage winding; The operation control module is used for the controller to calculate the voltage regulation requirement of the adjustable winding assembly based on the difference between the measured voltage value of the low-voltage winding and the rated voltage, and generate the voltage regulation logic; The trigger output module is used for the controller to output a corresponding control signal in a time sequence based on the voltage regulation logic to control the opening and closing of the IGBT switching mechanism and the switching on and off of the adjustable winding component into and out of the high-voltage winding; The trigger output module includes: a first triggering unit, configured to regulate voltage by operating the first voltage-regulating switch group when the first arc-extinguishing switch is closed, causing the voltage-regulating switch corresponding to the voltage-regulating winding to be connected to enter a pre-connection state based on a triggering strategy sent by the controller, closing the first IGBT, disconnecting the first arc-extinguishing switch, and supplying power through the first IGBT; the voltage-regulating switch is a magnetic latching relay; Cooperate with the first trigger unit to lock the phase, turn off the first IGBT before the voltage crosses zero, turn on the second IGBT when the voltage crosses zero, close the second arc suppression switch after switching, and turn off the second IGBT, so that the voltage regulating winding to be connected is connected in series with the high-voltage winding; The trigger output module further includes: a second triggering unit, configured to regulate voltage by operating the second voltage regulating switch group when the second arc suppression switch is closed, and to cause the voltage regulating switch corresponding to the voltage regulating winding to be connected to enter a pre-connection state based on the triggering strategy sent by the controller, close the second IGBT, disconnect the second arc suppression switch, and supply power through the second IGBT; Cooperating with the second trigger unit, it is used to close the second IGBT before the voltage passes through zero after phase locking, close the first IGBT when the voltage passes through zero, close the first arc suppression switch after switching, and disconnect the first IGBT, so that the voltage regulating winding to be connected is connected in series with the high-voltage winding.

10. The control system according to claim 9, wherein: The control system further includes: a power supply module; The power supply module is used to provide electrical energy to the control system.

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