Voltage regulating transformer

Abstract

The invention discloses a voltage regulating transformer. The voltage regulating transformer comprises a high-voltage winding, an exciting winding, a voltage regulating structure and at least two low-voltage windings, wherein the voltage regulating structure comprises a voltage regulating winding and a voltage regulating switch; the low-voltage winding is in magnetic field coupling connection with the high-voltage winding, the high-voltage winding is in series connection with the voltage regulating switch and then is in parallel connection with the excitation winding, and the voltage regulating winding is in magnetic field coupling connection with the excitation winding. Wherein the voltage regulating switch is used for regulating the number of turns of the voltage regulating winding connected to the high-voltage side loop. The voltage regulating switch is connected with the excitation winding in parallel after being connected with the high-voltage winding in series, so that the current on the tapping lead can be reduced, the phenomenon of magnetic field overheating caused by a voltage regulating structure is improved, the specification required by the tapping lead is reduced, the production difficulty is reduced, and the production efficiency is improved. And the production efficiency of the adjustable transformer, the reliability of the production quality and the operability are improved. Meanwhile, the number of voltage regulating switches and voltage regulating windings can be reduced, and the economical efficiency of the voltage regulating transformer is further improved.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of transformers, and in particular to a voltage regulating transformer. Background Art

[0002] In the prior art, there are two ways to implement the tap voltage regulation function of the transformer low-voltage winding, namely, direct voltage regulation of the low-voltage voltage regulating winding and indirect voltage regulation of the series winding. When direct voltage regulation of the low-voltage voltage regulating winding and indirect voltage regulation of the series winding are adopted, the economy and operability are relatively poor, and it is easy to cause overheating of the surrounding structural parts. Summary of the invention

[0003] The invention provides a voltage regulating transformer to improve the economy and operability of the voltage regulating transformer, improve the overheating phenomenon of structural parts in the voltage regulating transformer, and simplify the structure of the voltage regulating transformer.

[0004] In a first aspect, an embodiment of the present invention provides a voltage regulating transformer, comprising a high voltage winding, an excitation winding, a voltage regulating structure and at least two low voltage windings, wherein the voltage regulating structure comprises a voltage regulating winding and a voltage regulating switch;

[0005] The low voltage winding is magnetically coupled to the high voltage winding, the high voltage winding is connected in series with the voltage regulating switch and then connected in parallel with the excitation winding, and the voltage regulating winding is magnetically coupled to the excitation winding; wherein the voltage regulating switch is used to adjust the number of winding turns of the voltage regulating winding connected to the high voltage side circuit.

[0006] Optionally, the polarity active end of the voltage regulating switch is connected to the first end of the high-voltage winding, the polarity fixed end of the voltage regulating switch is connected to the two ends of the voltage regulating winding, the tap fixed end of the voltage regulating switch is connected to the tap tap of the voltage regulating winding, the tap active end of the voltage regulating switch is connected to the first end of the excitation winding as the end of the high-voltage side single-phase winding, and the second end of the excitation winding is connected to the second end of the high-voltage winding as the head end of the high-voltage side single-phase winding.

[0007] Optionally, the voltage regulating transformer further includes a first iron core and a second iron core;

[0008] The high-voltage winding and the low-voltage winding are wound on the first iron core; the voltage regulating winding and the excitation winding are wound on the second iron core.

[0009] Optionally, the excitation winding and the voltage regulating winding are arranged on the second iron core from inside to outside.

[0010] Optionally, the connection mode of the high-voltage side winding is star connection or triangle connection, and the winding on the high-voltage side includes the high-voltage winding, the voltage regulating winding and the excitation winding.

[0011] Optionally, the excitation winding includes a first-phase excitation winding, a second-phase excitation winding and a third-phase excitation winding; when the high-voltage side winding is connected in a star connection, the first ends of the excitation windings of different phases are connected to serve as the neutral point of the high-voltage side winding; when the high-voltage side winding is connected in a triangle connection, the first end of the first-phase excitation winding is connected to the second end of the second-phase excitation winding, the first end of the second-phase excitation winding is connected to the second end of the third-phase excitation winding, and the first end of the third-phase excitation winding is connected to the second end of the first-phase excitation winding.

[0012] Optionally, at least two of the low-voltage windings are connected in different ways.

[0013] Optionally, the low voltage winding is connected in a star connection, a delta connection or a zigzag connection.

[0014] Optionally, the winding direction of the excitation winding is the same as or opposite to that of the voltage regulating winding.

[0015] Optionally, the ratio of the number of turns of the voltage regulating winding to the number of turns of the high-voltage winding is the voltage regulating range of the voltage regulating transformer.

[0016] The technical solution of the embodiment of the present invention is to connect the voltage regulating switch in series with the high-voltage winding and then connect it in parallel with the excitation winding. Then, the voltage at both ends of the high-voltage winding can be adjusted by adjusting the number of winding turns of the voltage regulating winding connected to the high-voltage side loop through the voltage regulating switch. Then, through the magnetic field coupling effect of the high-voltage winding and the low-voltage winding, the voltage at both ends of the low-voltage winding can be adjusted, and the voltage regulation of the low-voltage side of the voltage regulating transformer is realized. Since the voltage regulating structure is connected in series with the high-voltage winding, the current on the voltage regulating structure is equal to the current on the high-voltage winding. Compared with the situation where the current on the voltage regulating structure is equal to the current on the low-voltage winding, the current on the voltage regulating structure can be reduced, and the phenomenon of magnetic field overheating caused by the voltage regulating structure can be improved, thereby saving the shielding structure, simplifying the structure of the voltage regulating transformer, and improving the economy of the voltage regulating transformer. At the same time, the current on the tapping lead in the voltage regulating structure can be reduced, and the specifications required for the tapping lead can be reduced, which reduces the production difficulty and improves the production efficiency, production quality reliability and operability of the adjustable transformer. Moreover, the voltage regulating structure is arranged on the high voltage side, and only one voltage regulating structure is needed to regulate the voltage of at least two low voltage windings, thereby reducing the number of voltage regulating structures required, further reducing the cost of the voltage regulating transformer, and improving the economic efficiency of the voltage regulating transformer. In addition, the voltage regulating transformer provided by the present application does not need to be additionally provided with a series winding, thereby reducing the number of windings required for the voltage regulating transformer, further reducing the cost of the voltage regulating transformer, and improving the economic efficiency of the voltage regulating transformer. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of the winding structure of a voltage regulating transformer provided for related technology;

[0018] Figure 2 A schematic diagram of the winding structure of another voltage regulating transformer provided in the related art;

[0019] Figure 3 A schematic diagram of the winding structure of a voltage regulating transformer provided in an embodiment of the present invention;

[0020] Figure 4 A schematic diagram of the winding structure of another voltage regulating transformer provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0021] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0022] Figure 1 A schematic diagram of the winding structure of a voltage regulating transformer is provided for related technology. Figure 1 As shown, the voltage regulating transformer includes a high-voltage winding, two low-voltage windings, two low-voltage regulating windings and two voltage regulating switches; the two voltage regulating switches are respectively arranged on the two low-voltage regulating windings, and then the low-voltage regulating windings are arranged to be connected in series with the low-voltage windings, so that the number of turns of the low-voltage regulating winding connected to the low-voltage side loop is adjusted by the voltage regulating switch, and then the turn ratio of the high-voltage side winding and the low-voltage side winding is adjusted to achieve voltage regulation on the low-voltage side. For example, as Figure 1As shown, the three-phase high-voltage windings of the high-voltage winding are AX, BY and CZ connected in star shape, and the neutral point is O. After the three-phase low-voltage winding of the first low-voltage winding is star-connected, one end of the three-phase low-voltage winding is respectively connected to the three active ends a1k, b1k and c1k of the polarity selector of the first voltage regulating switch, and the three groups of fixed ends of the polarity selector are respectively connected to the two ends of the three-phase low-voltage winding; the other ends of the three-phase low-voltage winding are respectively used as the three-phase low-voltage line terminals a1, b1 and c1 of the low-voltage winding, and the tap selector of the first voltage regulating switch includes three groups of tapping terminals (the first group of tapping terminals is x11, x12, x13...x1n, x1n+1; the second group of tapping terminals is y11, y12, y13...y1n, y1n+1; the third group of tapping terminals is z11, z12, z13...z1n, z1n+1), which are respectively connected to the tapping taps of each phase of the low-voltage regulating winding, and the three connection ends of the tap selector of the first voltage regulating switch are connected to each other as the neutral point o of the first low-voltage winding. After the three-phase low-voltage winding of the second low-voltage winding is connected in a triangle, one end of the three-phase low-voltage winding is respectively connected to the three active ends a2k, b2k and c2k of the polarity selector of the second voltage regulating switch, and the three groups of fixed ends of the polarity selector are respectively connected to the two ends of the three-phase low-voltage winding; the other ends of the three-phase low-voltage winding serve as the three-phase low-voltage line terminals a2, b2 and c2 of the low-voltage winding, and the tap selector of the second voltage regulating switch includes three groups of tapping terminals (the first group of tapping terminals are x21, x22, x23...x2n, x2n+1; the second group of tapping terminals are y21, y22, y23...y2n, y2n+1; the third group of tapping terminals are z21, z22, z23...z2n, z2n+1), which are respectively connected to the tapping taps of each phase of the low-voltage regulating winding, and the three connection ends of the tap selector of the second voltage regulating switch are respectively connected to the low-voltage winding of another phase. Figure 1 In the structure, the number of voltage regulators is the same as the number of low-voltage windings, which is not economical. The current in the tap lead and the low-voltage winding is very large, so the cable specifications required are relatively large, and the number of tap leads is relatively large. It is difficult to bend and fix them during production, resulting in low production efficiency and high total cost of lead cables. During extreme tap voltage regulation, the tap wire has a large ampere-turn number, which can easily cause overheating of surrounding structural parts. Certain countermeasures need to be considered (such as copper shielding and magnetic shielding), which brings certain complexity to the structure of the voltage regulating transformer.

[0023] Figure 2 Another winding structure diagram of a voltage regulating transformer provided in the related art. Figure 2 As shown, Figure 1The difference is that the voltage-regulating transformer includes a voltage-regulating winding and a voltage-regulating switch (the three active ends of the polarity selector of the voltage-regulating switch are labeled ak, bk and ck respectively, and the three groups of tapping ends of the tap selector of the voltage-regulating switch are labeled x1, x2, x3...xn, xn+1; y1, y2, y3...yn, yn+1; z1, z2, z3...zn, zn+1 respectively), and includes an excitation winding and two series windings. After the voltage-regulating switch is connected to the voltage-regulating winding, it is connected in series with the three excitation windings in the excitation winding. Each series winding is connected in series with each low-voltage winding. At this time, the low-voltage side voltage of the voltage-regulating transformer is the sum of the voltage at both ends of the series winding and the voltage at both ends of the low-voltage winding. There is a magnetic field coupling relationship between the high-voltage winding and the voltage-regulating winding, and there is a magnetic field coupling relationship between the excitation winding and the series winding. The turns ratio between the high-voltage winding and the voltage regulating winding can be adjusted by the voltage regulating switch, so that the voltage at both ends of the voltage regulating winding can be adjusted, and then the voltage at both ends of the excitation winding can be adjusted. The turns ratio between the excitation winding and the series winding remains unchanged. When the voltage at both ends of the excitation winding changes, the voltage at both ends of the series winding can change, so that the voltage on the low-voltage side of the voltage regulating transformer can be adjusted. Figure 2 In the structure, each low-voltage winding needs to be connected in series with an additional series winding, which increases the windings required for the voltage-regulating transformer, increases material costs and labor costs, and reduces the economic efficiency of the voltage-regulating transformer. In addition, there are many connecting leads between the low-voltage winding and the series winding, and the problem of overheating of the structural parts caused by the large ampere-turns also needs to be considered.

[0024] In view of the above technical problems, an embodiment of the present invention provides a voltage regulating transformer. Figure 3 A schematic diagram of the winding structure of a voltage regulating transformer provided in an embodiment of the present invention. Figure 3 As shown, the voltage regulating transformer includes a high-voltage winding 10, an excitation winding 20, a voltage regulating structure 30 and at least two low-voltage windings 40, and the voltage regulating structure 30 includes a voltage regulating winding and a voltage regulating switch; the low-voltage winding 40 is magnetically coupled with the high-voltage winding 10, the high-voltage winding 10 is connected in series with the voltage regulating switch and then connected in parallel with the excitation winding 20, and the voltage regulating winding is magnetically coupled with the excitation winding 20; wherein the voltage regulating switch is used to adjust the number of winding turns of the voltage regulating winding connected to the high-voltage side circuit.

[0025] Specifically, the high-voltage winding 10, the excitation winding 20 and the low-voltage winding 40 all include three-phase windings. The voltage regulating structure 30 includes three voltage regulating substructures, each of which is provided with a voltage regulating winding, which is connected in series with the three-phase high-voltage windings and then connected to the excitation winding. Then the second end A1 of the high-voltage winding of the first phase is connected to the second end A' of the excitation winding of the first phase, the first end of the high-voltage winding of the first phase is connected to the first end AK of the voltage regulating substructure of the first phase, and the second end of the voltage regulating substructure of the first phase is connected to the first end X1 of the excitation winding of the first phase. Similarly, the second end B1 of the high-voltage winding of the second phase is connected to the second end B' of the excitation winding of the second phase, the first end of the high-voltage winding of the second phase is connected to the first end BK of the voltage regulating substructure of the second phase, and the second end of the voltage regulating substructure of the second phase is connected to the first end Y1 of the excitation winding of the second phase. The second end C1 of the high-voltage winding of the third phase is connected to the second end C' of the excitation winding of the third phase, the first end of the high-voltage winding of the third phase is connected to the first end CK of the voltage regulating substructure of the third phase, and the second end of the voltage regulating substructure of the third phase is connected to the first end Z1 of the excitation winding of the third phase. Among them, the second end of the high-voltage winding serves as the high-voltage line end of the high-voltage winding 10. At this time, the high-voltage winding 10 is connected in series with the winding connected to the high-voltage side loop in the voltage regulating structure 30, and then connected in parallel with the excitation winding 20. According to Kirchhoff's second law of the circuit, the sum of the voltage at both ends of the high-voltage winding 10 and the voltage at both ends of the winding connected to the high-voltage side loop in the voltage regulating structure 30 is equal to the voltage at both ends of the excitation winding 20. When high voltage electricity is input to the high-voltage line end of the high-voltage winding 10, the number of turns of the excitation winding 20 remains unchanged. According to Faraday's law of electromagnetic induction, the voltage at both ends of the excitation winding 20 remains unchanged. The voltage regulating structure 30 includes a winding, which is coupled to the excitation winding 20 magnetic field. When the number of turns of the winding connected to the high-voltage side loop of the voltage regulating structure 30 changes, the turn ratio of the winding in the voltage regulating structure 30 to the excitation winding 20 changes, so that the voltage at both ends of the voltage regulating structure 30 changes, and then the voltage at both ends of the high-voltage winding 10 changes in the opposite direction to the voltage at both ends of the voltage regulating structure 30. The low-voltage winding 40 is connected to the high-voltage winding 10 by magnetic field coupling. When the voltage at both ends of the high-voltage winding 10 changes, the voltage at both ends of the low-voltage winding 40 changes with the voltage at both ends of the high-voltage winding 10, so that the voltage at both ends of the high-voltage winding 10 can be adjusted by the voltage regulating structure 30, and then the voltage at both ends of the low-voltage winding 40 can be adjusted, so as to achieve voltage regulation on the low-voltage side of the voltage regulating transformer. Since the voltage regulating structure 30 is connected in series with the high voltage winding 10, the current on the voltage regulating structure 30 is equal to the current on the high voltage winding 10. Compared with the case where the current on the voltage regulating structure 30 is equal to the current on the low voltage winding 40, the current on the voltage regulating structure 30 can be reduced, and the phenomenon of magnetic field overheating caused by the voltage regulating structure 30 can be improved, thereby saving the shielding structure, simplifying the structure of the voltage regulating transformer, and improving the economy of the voltage regulating transformer. Exemplarily, the shielding structure may include a magnetic shielding structure and a copper shielding structure.At the same time, the current on the tapping lead required in the voltage regulating structure 30 can be reduced, and the specifications required for the tapping lead can be reduced, which reduces the difficulty of production and improves the production efficiency, reliability of production quality and operability of the adjustable transformer. Moreover, the voltage regulating structure 30 is arranged on the high-voltage side, and only one voltage regulating structure 30 is required to adjust the voltage of at least two low-voltage windings 40, which reduces the number of voltage regulating structures 30 required, and can further reduce the cost of the voltage regulating transformer and improve the economy of the voltage regulating transformer. In addition, the voltage regulating transformer provided by the present application does not need to be additionally provided with a series winding, thereby reducing the number of windings required for the voltage regulating transformer, further reducing the cost of the voltage regulating transformer and improving the economy of the voltage regulating transformer.

[0026] The technical solution of this embodiment is to connect the voltage regulating switch in series with the high-voltage winding and then connect it in parallel with the excitation winding. Then, the voltage at both ends of the high-voltage winding can be adjusted by adjusting the number of winding turns of the voltage regulating winding connected to the high-voltage side circuit through the voltage regulating switch. Furthermore, through the magnetic field coupling effect of the high-voltage winding and the low-voltage winding, the voltage at both ends of the low-voltage winding can be adjusted, and the voltage regulation of the low-voltage side of the voltage regulating transformer is realized. Since the voltage regulating structure is connected in series with the high-voltage winding, the current on the voltage regulating structure is equal to the current on the high-voltage winding. Compared with the situation where the current on the voltage regulating structure is equal to the current on the low-voltage winding, the current on the voltage regulating structure can be reduced, and the phenomenon of magnetic field overheating caused by the voltage regulating structure can be improved, thereby saving the shielding structure, simplifying the structure of the voltage regulating transformer, and improving the economy of the voltage regulating transformer. At the same time, the current on the tapping lead in the voltage regulating structure can be reduced, and the specifications required for the tapping lead can be reduced, which reduces the production difficulty and improves the production efficiency, production quality reliability and operability of the adjustable transformer. Moreover, the voltage regulating structure is arranged on the high voltage side, and only one voltage regulating structure is needed to regulate the voltage of at least two low voltage windings, thereby reducing the number of voltage regulating structures required, further reducing the cost of the voltage regulating transformer, and improving the economic efficiency of the voltage regulating transformer. In addition, the voltage regulating transformer provided by the present application does not need to be additionally provided with a series winding, thereby reducing the number of windings required for the voltage regulating transformer, further reducing the cost of the voltage regulating transformer, and improving the economic efficiency of the voltage regulating transformer.

[0027] Continue to refer Figure 3 The polarity active end of the voltage regulating switch is connected to the first end of the high-voltage winding 10, the polarity fixed end of the voltage regulating switch is connected to the two ends of the voltage regulating winding, the tap fixed end of the voltage regulating switch is connected to the tap tap of the voltage regulating winding, the tap active end of the voltage regulating switch is connected to the first end of the excitation winding 20, as the end of the high-voltage side single-phase winding, and the second end of the excitation winding 20 is connected to the second end of the high-voltage winding 10, as the head end of the high-voltage side single-phase winding.

[0028] Specifically, the voltage regulating winding includes a three-phase voltage regulating winding. The voltage regulating switch includes three sub-switches, which are respectively connected to the three-phase voltage regulating windings, and are used to respectively adjust the number of winding turns of each phase of the voltage regulating winding connected to the high-voltage side circuit. Each sub-switch includes a polarity selector and a tap selector, and each voltage regulating winding may include at least two tap taps. The polarity selector can select the winding polarity of the voltage regulating winding connected to the high-voltage side circuit, and the tap selector can select the number of winding turns of the voltage regulating winding connected to the high-voltage side circuit. By controlling the polarity selector and the tap selector, the direction and number of turns of the voltage regulating winding connected to the high-voltage side circuit can be adjusted, so that the positive and negative and the magnitude of the voltage at both ends of the voltage regulating winding can be adjusted, and then the voltage at both ends of the high-voltage winding can be adjusted. Finally, the voltage at both ends of the low-voltage winding is adjusted according to the voltage at both ends of the high-voltage winding, so as to achieve voltage regulation on the low-voltage side of the voltage regulating transformer. Exemplarily, refer to Figure 3 , the second end A' of the excitation winding of the first phase is connected to the second end A1 of the high-voltage winding of the first phase, as the head end of the single-phase winding on the high-voltage side, that is, the high-voltage line end, which can be connected to the power grid for inputting high voltage. The polarity active end of the voltage regulating sub-switch of the first phase is connected to the first end of the high-voltage winding of the first phase as the first end AK of the voltage regulating sub-structure of the first phase, the first polarity fixed end - of the voltage regulating sub-switch of the first phase is connected to the first end of the voltage regulating winding of the first phase, the second polarity fixed end + of the voltage regulating sub-switch of the first phase is connected to the second end of the voltage regulating winding of the first phase, and the n+1 tapping fixed ends x'1, x'2, x'3...x'n, x'n+1 of the voltage regulating sub-switch of the first phase are respectively connected to the n+1 tapping taps of the voltage regulating winding of the first phase through a tapping lead. Among them, the number of turns of the voltage regulating winding corresponding to the first tapping tap and the last tapping tap is the same, then the voltage regulating range of the voltage regulating winding of the first phase can be divided into n gears. When the percentage of the voltage regulation range of each gear relative to the rated voltage on the high-voltage side of the voltage regulating transformer is m%, the percentage of the voltage regulation range of the voltage regulating transformer relative to the rated voltage on the high-voltage side of the voltage regulating transformer is ±n×m%. The tapping active end of the first-phase voltage regulating sub-switch is connected to the first end X1 of the excitation winding of the first phase as the second end of the voltage regulating sub-structure of the first phase, and as the end of the single-phase winding on the high-voltage side, it can be connected to the second end of the excitation winding of another phase or the first end of the excitation winding of another phase to achieve a triangle connection or a star connection on the high-voltage side. During the voltage regulation process of the voltage regulating transformer, when the polarity active end of the first-phase voltage regulating sub-switch is connected to the second polarity fixed end +, and the tapping active end is connected to the first tapping fixed end x'1, the voltage on the voltage regulating winding of the first phase is -n×m%×U1. Among them, U1 is the rated voltage on the high-voltage side. The excitation winding voltage of the first phase is the rated voltage U1 on the high-voltage side, and the voltage across the high-voltage winding of the first phase is: [1-(-n×m%)]×U1; before voltage regulation, when the rated voltage of the low-voltage winding is U2, then under the current voltage regulation conditions, according to Faraday's law of electromagnetic induction, the voltage of the low-voltage winding is U2×(1+n×m%). Figure 3 It is shown in the example that the voltage regulating transformer includes two low-voltage windings 40. Before voltage regulation, the rated voltages of the low-voltage windings in the first low-voltage winding 40 and the second low-voltage winding 40 are U21 and U22, respectively. Then, under the current voltage regulation conditions, the voltage of the low-voltage winding in the first low-voltage winding 40 is U21×(1+n×m%), and the voltage of the low-voltage winding in the second low-voltage winding 40 is U22×(1+n×m%). When the polarity active end of the voltage regulating sub-switch of the first phase is connected to the first polarity fixed end -, and the tap active end is connected to the last tap fixed end x'n+1, the voltage on the voltage regulating winding of the first phase is n×m%×U1. Among them, U1 is the rated voltage on the high-voltage side. The excitation winding voltage of the first phase is the rated voltage U1 on the high-voltage side, and the voltage across the high-voltage winding of the first phase is: [1-(n×m%)]×U1; before voltage regulation, when the rated voltage of the low-voltage winding is U2, then under the current voltage regulation conditions, according to Faraday's law of electromagnetic induction, the voltage of the low-voltage winding is U2×(1-n×m%). Figure 3 It is shown in the example that the voltage regulating transformer includes two low-voltage windings 40. Before the voltage regulation, the rated voltages of the low-voltage windings in the first low-voltage winding 40 and the second low-voltage winding 40 are U21 and U22 respectively. Under the current voltage regulation conditions, the voltage of the low-voltage winding in the first low-voltage winding 40 is U21×(1-n×m%), and the voltage of the low-voltage winding in the second low-voltage winding 40 is U22×(1-n×m%). In addition, when the rated capacity of the voltage regulating transformer is S, the capacity of each phase winding of the high-voltage winding 10 and the low-voltage winding 40 is S / 3. When the voltage regulation range of the voltage regulating winding is ±n×m%, the capacity of the voltage regulating winding is (n×m%) / (1-n×m%) of the capacity of the high-voltage winding, the voltage range of the voltage regulating winding is n×m% of the voltage of the excitation winding, the voltage range of the high-voltage winding is 1-n×m% of the voltage of the excitation winding, and the voltage range of the voltage regulating winding is (n×m%) / (1-n×m%) of the voltage of the high-voltage winding.

[0029] Similarly, the second end B' of the second phase excitation winding is connected to the second end B1 of the second phase high voltage winding, and as the head end of the high voltage side single phase winding, i.e., the high voltage line end, it can be connected to the power grid for inputting high voltage. The polarity active end of the second phase voltage regulating sub-switch is connected to the first end BK of the second phase voltage regulating sub-structure with the first end of the second phase high voltage winding, the first polarity fixed end - of the second phase voltage regulating sub-switch is connected to the first end of the second phase voltage regulating winding, the second polarity fixed end + of the second phase voltage regulating sub-switch is connected to the second end of the second phase voltage regulating winding, and the n+1 tapping fixed ends y'1, y'2, y'3...y'n, y'n+1 of the second phase voltage regulating sub-switch are respectively connected to the n+1 tapping taps of the second phase voltage regulating winding through a tapping lead. The tapped active end of the second-phase voltage regulating sub-switch is connected to the first end Y1 of the second-phase excitation winding as the second end of the second-phase voltage regulating sub-structure, and as the end of the high-voltage side single-phase winding, it can be connected to the second end of the excitation winding of another phase or the first end of the excitation winding of another phase to achieve a triangle connection or a star connection on the high-voltage side. The second end C' of the third-phase excitation winding is connected to the second end C1 of the third-phase high-voltage winding, and as the head end of the high-voltage side single-phase winding, that is, the high-voltage line end, it can be connected to the power grid for inputting high voltage. The polarity active end of the third-phase voltage-regulating sub-switch is connected to the first end of the third-phase high-voltage winding as the first end CK of the third-phase voltage-regulating sub-structure, the first polarity fixed end - of the third-phase voltage-regulating sub-switch is connected to the first end of the third-phase voltage-regulating winding, the second polarity fixed end + of the third-phase voltage-regulating sub-switch is connected to the second end of the third-phase voltage-regulating winding, the n+1 tapping fixed ends z'1, z'2, z'3...z'n, z'n+1 of the third-phase voltage-regulating sub-switch are respectively connected to the n+1 tapping taps of the third-phase voltage-regulating winding through a tapping lead. The tapping active end of the third-phase voltage-regulating sub-switch is connected to the first end Z1 of the third-phase excitation winding as the second end of the third-phase voltage-regulating sub-structure, the third-phase excitation winding, and the end of the high-voltage side single-phase winding, and can be connected to the second end of the excitation winding of another phase or the first end of the excitation winding of another phase, to achieve a triangle connection or a star connection on the high-voltage side. The voltage regulation process of the second phase and the voltage regulation process of the third phase are the same as the voltage regulation process of the first phase, and will not be repeated here.

[0030] On the basis of the above technical solution, the winding direction of the excitation winding is the same as that of the voltage regulating winding, so that when the polarity active end of the voltage regulating sub-switch of the first phase is connected to the second polarity fixed end +, and the tap active end is connected to the first tap fixed end x'1, the voltage on the voltage regulating winding of the first phase is -n×m%×U1. When the polarity active end of the voltage regulating sub-switch of the first phase is connected to the first polarity fixed end -, and the tap active end is connected to the last tap fixed end x'n+1, the voltage on the voltage regulating winding of the first phase is n×m%×U1. In some embodiments, the winding direction of the excitation winding can also be set to be opposite to that of the voltage regulating winding. When the polarity active end of the voltage regulating sub-switch of the first phase is connected to the second polarity fixed end +, and the tap active end is connected to the first tap fixed end x'1, the voltage on the voltage regulating winding of the first phase is n×m%×U1. When the polarity active end of the voltage regulating sub-switch of the first phase is connected to the first polarity fixed end -, and the tap active end is connected to the last tap fixed end x'n+1, the voltage on the voltage regulating winding of the first phase is -n×m%×U1. At this time, under the same voltage regulation conditions, the voltage regulation range of the voltage regulating transformer is opposite in positive and negative, and the voltage regulation of the low-voltage side of the voltage regulating transformer can also be achieved.

[0031] In some embodiments, the ratio of the number of turns of the voltage regulating winding to the number of turns of the high voltage winding is the voltage regulating range of the voltage regulating transformer.

[0032] Specifically, the voltage regulating winding is connected in series with the high-voltage winding so that the current of the voltage regulating winding is the same as the current of the high-voltage winding. At this time, the number of turns of the voltage regulating winding is set to the product of the number of turns of the high-voltage winding and the voltage regulation range, so that the voltage variation range of the voltage regulating winding meets the voltage regulation range of the voltage regulating transformer. Exemplarily, when the voltage regulation range of the voltage regulating transformer is ±10%, the ratio of the number of turns of the voltage regulating winding to the number of turns of the high-voltage winding is 10%.

[0033] In some embodiments, the voltage regulating transformer further includes a first core and a second core; the high voltage winding and the low voltage winding are wound on the first core; and the voltage regulating winding and the excitation winding are wound on the second core.

[0034] Specifically, the high-voltage winding and the low-voltage winding can be arranged on the same iron core, so that the high-voltage winding and the low-voltage winding are magnetically coupled. The voltage regulating winding and the excitation winding can be arranged on the same iron core, so that the voltage regulating winding and the excitation winding are magnetically coupled, so that when the number of turns of the voltage regulating winding connected to the high-voltage side circuit changes, the voltage of the low-voltage winding can be adjusted by changing the voltage of the high-voltage winding.

[0035] For example, Table 1 is a structural performance comparison table of different voltage regulating transformers provided in an embodiment of the present invention, wherein method 1 is Figure 1 The structural performance of the voltage regulating transformer provided by method 2 is Figure 2The structural performance of the voltage regulating transformer provided by method 3 is Figure 3 The structural performance of the voltage regulating transformer provided. The number of switches is the number of voltage regulating switches, the number of cores is the number of cores required for the voltage regulating transformer, the number of windings is the sum of the number of windings including the high-voltage winding, the excitation winding, the voltage regulating winding and the low-voltage winding, the tap lead cable specification is the diameter of the tap lead used to connect the tap tap of the voltage regulating winding with the tap fixed end of the voltage regulating switch, the production difficulty is the difficulty in the production process of the voltage regulating switch, and the total cost is the cost required in the production process of the voltage regulating transformer. As shown in Table 1, Figure 3 The number of windings required for the voltage regulating transformer provided is (N+3)×3, where N is the number of low voltage windings. Figure 1 The voltage regulating transformer and Figure 2 The required number of voltage-regulating transformers provided reduces the cost of the voltage-regulating transformer and improves the economy of the voltage-regulating transformer. Moreover, the current on the voltage-regulating winding is equal to the current on the high-voltage winding, which is less than Figure 1 The voltage regulating transformer and Figure 2 The invention provides a current on a voltage regulating winding and a tapping lead in a voltage regulating transformer, thereby reducing the specifications required for the tapping lead, and reducing the production difficulty and the total cost.

[0036]

[0037] On the basis of the above technical solution, the excitation winding and the voltage regulating winding are arranged on the second core from the inside to the outside, which can avoid the excitation winding affecting the connection of the voltage regulating winding and reduce the connection difficulty of the voltage regulating winding.

[0038] In some embodiments, the connection mode of the high-voltage side winding is star connection or delta connection, and the winding on the high-voltage side includes a high-voltage winding, a voltage regulating winding and an excitation winding.

[0039] Specifically, Figure 3 As shown, in the same phase on the high-voltage side, the high-voltage winding is connected in series with the voltage regulating winding through the voltage regulating switch, and then connected in parallel with the excitation winding. At this time, the two ends of the excitation winding in each phase can be used as the high-voltage line ends of the high-voltage side winding. The excitation winding includes a first-phase excitation winding, a second-phase excitation winding, and a third-phase excitation winding; when the connection mode of the high-voltage side winding is a star connection, the first ends of the excitation windings of different phases are connected as the neutral point O1 of the high-voltage side winding. Specifically, the first end X1 of the excitation winding of the first phase, the first end Y1 of the excitation winding of the second phase, and the first end Z1 of the excitation winding of the third phase are connected and serve as the neutral point O1 of the high-voltage side winding.

[0040] Figure 4 A schematic diagram of the winding structure of another voltage regulating transformer provided in an embodiment of the present invention. Figure 4As shown, the connection mode of the high-voltage side winding is a triangle connection. Specifically, the first end X1 of the first phase excitation winding is connected to the second end B' of the second phase excitation winding, the first end Y1 of the second phase excitation winding is connected to the second end C' of the third phase excitation winding, and the first end Z1 of the third phase excitation winding is connected to the second end A' of the first phase excitation winding.

[0041] Continue to refer Figure 3 and Figure 4 , the connection modes of at least two low voltage windings 40 are different.

[0042] Specifically, Figure 3 and Figure 4 In the figure, it is shown that the voltage regulating transformer includes two low-voltage windings 40. The connection mode of one low-voltage winding 40 is star connection, and the connection mode of the other low-voltage winding 40 is triangle connection. By setting the connection modes of the low-voltage windings 40 to be different, different low-voltage windings 40 can output different voltages, thereby increasing the use range of the voltage regulating transformer. Exemplarily, each low-voltage winding 40 includes a three-phase low-voltage winding. When the first low-voltage winding 40 is star-connected, the first end x1' of the first-phase low-voltage winding, the first end y1' of the second-phase low-voltage winding and the first end z1' of the third-phase low-voltage winding are connected and serve as the neutral point o1 of the first low-voltage winding 40. The second end of the first-phase low-voltage winding serves as the low-voltage line end a'1 of the first-phase low-voltage winding, the second end of the second-phase low-voltage winding serves as the low-voltage line end b'1 of the second-phase low-voltage winding, and the second end of the third-phase low-voltage winding serves as the low-voltage line end c'1 of the third-phase low-voltage winding. When the second low-voltage winding 40 is connected in a triangle, the second end of the first-phase low-voltage winding serves as the low-voltage line end a'2 of the first-phase low-voltage winding, the second end of the second-phase low-voltage winding serves as the low-voltage line end b'2 of the second-phase low-voltage winding, and the second end of the third-phase low-voltage winding serves as the low-voltage line end c'2 of the third-phase low-voltage winding. The first end x2' of the first-phase low-voltage winding is connected to the second end of the second-phase low-voltage winding, the first end y2' of the second-phase low-voltage winding is connected to the second end of the third-phase low-voltage winding, and the first end z2' of the third-phase low-voltage winding is connected to the second end of the first-phase low-voltage winding.

[0043] In some embodiments, the low voltage winding is connected in a star connection, a delta connection or a zigzag connection.

[0044] Continue to refer Figure 3 and Figure 4 , exemplarily showing that the connection modes of the two low-voltage windings 40 include star connection and delta connection. In other embodiments, the connection mode of the low-voltage windings 40 can also be set to a zigzag connection, in which case the connection group number of the low-voltage windings 40 can be z.

[0045] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A voltage regulating transformer, It is characterized in that It includes a high-voltage winding, an excitation winding, a voltage regulating structure and at least two low-voltage windings, wherein the voltage regulating structure includes a voltage regulating winding and a voltage regulating switch; The low voltage winding is magnetically coupled to the high voltage winding, the high voltage winding is connected in series with the voltage regulating switch and then connected in parallel with the excitation winding, and the voltage regulating winding is magnetically coupled to the excitation winding; wherein the voltage regulating switch is used to adjust the number of winding turns of the voltage regulating winding connected to the high voltage side circuit.

2. The voltage regulating transformer according to claim 1, It is characterized in that The polarity active end of the voltage regulating switch is connected to the first end of the high-voltage winding, the polarity fixed end of the voltage regulating switch is connected to the two ends of the voltage regulating winding, the tap fixed end of the voltage regulating switch is connected to the tap tap of the voltage regulating winding, the tap active end of the voltage regulating switch is connected to the first end of the excitation winding as the end of the high-voltage side single-phase winding, and the second end of the excitation winding is connected to the second end of the high-voltage winding as the head end of the high-voltage side single-phase winding.

3. The voltage regulating transformer according to claim 2, It is characterized in that Also includes a first core and a second core; The high-voltage winding and the low-voltage winding are wound on the first iron core; the voltage regulating winding and the excitation winding are wound on the second iron core.

4. The voltage regulating transformer according to claim 3, It is characterized in that The excitation winding and the voltage regulating winding are arranged on the second iron core from inside to outside.

5. The voltage regulating transformer according to any one of claims 1 to 4, It is characterized in that The connection mode of the high-voltage side winding is star connection or triangle connection, and the winding on the high-voltage side includes the high-voltage winding, the voltage regulating winding and the excitation winding.

6. The voltage regulating transformer according to claim 5, It is characterized in that The excitation winding comprises a first-phase excitation winding, a second-phase excitation winding and a third-phase excitation winding; When the connection mode of the high-voltage side winding is star connection, the first ends of the excitation windings of different phases are connected as the neutral point of the high-voltage side winding; When the connection mode of the high-voltage side winding is a triangle connection, the first end of the first phase excitation winding is connected to the second end of the second phase excitation winding, the first end of the second phase excitation winding is connected to the second end of the third phase excitation winding, and the first end of the third phase excitation winding is connected to the second end of the first phase excitation winding.

7. The voltage regulating transformer according to claim 1, It is characterized in that At least two of the low-voltage windings are connected in different ways.

8. The voltage regulating transformer according to claim 7, It is characterized in that The connection mode of the low voltage winding is star connection, triangle connection or zigzag connection.

9. The voltage regulating transformer according to claim 2, It is characterized in that The winding direction of the excitation winding is the same as or opposite to that of the voltage regulating winding.

10. The voltage regulating transformer according to claim 2, It is characterized in that The ratio of the number of turns of the voltage regulating winding to the number of turns of the high-voltage winding is the voltage regulating range of the voltage regulating transformer.

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