On-load seamless conversion transformer circuit and transformer device

Abstract

The present invention discloses an on-load seamless conversion transformer circuit, comprising a live terminal, a neutral terminal, a primary coil connected between the live and neutral terminals, and a secondary coil connected to a load. The primary coil has several voltage-regulating taps connected to the live terminal, each of which is connected in series with a voltage-regulating switch. The primary coil is also provided with a conversion tap, and a conversion circuit is connected in series with the neutral terminal. The conversion circuit includes a first conversion circuit and / or a second conversion circuit. The first conversion circuit includes a conversion resistor and a first conversion switch connected in series with the conversion resistor; the second conversion circuit includes a conversion inductor and a second conversion switch connected in series with the conversion inductor. The present invention also discloses a transformer device. The present invention can be used in power transformers, voltage regulators, and the like.

Description

Technical Field

[0001] The present invention relates to a voltage conversion circuit, more specifically to an on-load seamless conversion voltage conversion circuit and a voltage conversion device. Background Art

[0002] Voltage is a key indicator of power quality, and substandard voltage can severely harm the power grid. Excessive voltage excursions can impact the quality and yield of industrial and agricultural production, damage power equipment, and even cause systemic "voltage collapse," resulting in widespread power outages. Therefore, voltage regulation is often necessary to achieve the desired voltage.

[0003] There are generally two methods for regulating voltage in the prior art: one is no-load tap adjustment, and the other is load tap adjustment.

[0004] in:

[0005] When the tap is adjusted by no-load tap adjustment, the transformer must be shut down and disconnected before the adjustment is carried out. The advantage is safety and reliability, but the disadvantage is that the adjustment is inconvenient and often cannot meet the needs due to the limited number of tap positions.

[0006] The on-load tap adjustment method is convenient for adjustment. There is no need to shut down the transformer and adjustments can be made during operation. Generally, there are more tap positions, which makes it easy to meet requirements.

[0007] However, when the existing on-load tap-changing method is adopted, when the voltage regulating switches of the two taps are switched, it is easy to cause a momentary large voltage shock, and the voltage transition is not smooth enough. Summary of the Invention

[0008] In order to solve the technical problems in the prior art of easily causing instantaneous large voltage shocks and unstable voltage transition when adjusting voltage by on-load tap adjustment, the present invention provides an on-load seamless conversion transformer circuit and transformer device.

[0009] In order to solve the above technical problems, the technical solution adopted by the present invention is to design a loaded seamless conversion transformer circuit, including a live wire terminal, a neutral wire terminal, a primary coil connected between the live wire terminal and the neutral wire terminal, and a secondary coil connected to the load, the primary coil has several voltage-regulating taps connected to the live wire terminal, and a voltage-regulating switch is connected in series between each voltage-regulating tap and the live wire terminal; the primary coil is also provided with a conversion tap, and a conversion circuit is connected in series between the conversion tap and the neutral wire terminal, the conversion circuit includes a first conversion circuit and / or a second conversion circuit, the first conversion circuit includes a conversion resistor and a first conversion switch connected in series with the conversion resistor; the second conversion circuit includes a conversion inductor and a second conversion switch connected in series with the conversion inductor.

[0010] When the conversion circuit includes a first conversion circuit and a second conversion circuit, the second conversion circuit is connected in parallel with the first conversion circuit.

[0011] The on-load seamless conversion transformer circuit further includes:

[0012] a first selection switch connected in series between the conversion circuit and the neutral terminal;

[0013] A second selection switch is connected in series between the conversion circuit and the live wire terminal.

[0014] The on-load seamless transfer transformer circuit further includes a state transfer switch connected to the live wire end, and the state transfer switch is connected in parallel with the secondary coil.

[0015] The present invention also provides a transformer device, which comprises the above-mentioned on-load seamless conversion transformer circuit.

[0016] The present invention also provides an on-load seamless conversion transformer circuit, including a three-phase transformer, the three-phase transformer including three primary coils, one end of the three primary coils being connected together to form a connection point, and the other end being connected to three live wire ends respectively, each of the primary coils having a plurality of voltage regulating taps, each of the voltage regulating taps being connected in series with the connection point with a voltage regulating switch; each of the primary coils is also provided with a conversion tap, a conversion circuit being connected in series with the conversion tap and the connection point, the conversion circuit including a first conversion circuit and / or a second conversion circuit, the first conversion circuit including a conversion resistor and a first conversion switch connected in series with the conversion resistor; the second conversion circuit including a conversion inductor and a second conversion switch connected in series with the conversion inductor; and when the conversion circuit includes a first conversion circuit and a second conversion circuit, the second conversion circuit is connected in parallel with the first conversion circuit.

[0017] The present invention also provides a transformer device, which comprises the above-mentioned on-load seamless conversion transformer circuit.

[0018] The present invention also provides an on-load seamless conversion transformer circuit, including a three-phase transformer, the three-phase transformer including three secondary coils, one end of the three secondary coils being connected to the neutral line end, and the other end being connected to three live line ends respectively, each of the secondary coils having a plurality of voltage regulating taps, each of the voltage regulating taps being connected in series with the neutral line end respectively with a voltage regulating switch; each of the secondary coils is also provided with a conversion tap, a conversion circuit being connected in series between the conversion tap and the neutral line, the conversion circuit including a first conversion circuit and / or a second conversion circuit, the first conversion circuit including a conversion resistor and a first conversion switch connected in series with the conversion resistor; the second conversion circuit including a conversion inductor and a second conversion switch connected in series with the conversion inductor; and when the conversion circuit includes the first conversion circuit and the second conversion circuit, the second conversion circuit is connected in parallel with the first conversion circuit.

[0019] The present invention also provides a transformer device, which comprises the above-mentioned on-load seamless conversion transformer circuit.

[0020] The present invention provides a transfer tap on the primary coil, with a conversion circuit connected in series between the transfer tap and the neutral terminal. The conversion circuit includes a first conversion circuit and / or a second conversion circuit. The first conversion circuit includes a conversion resistor and a first conversion switch connected in series with the conversion resistor; the second conversion circuit includes a conversion inductor and a second conversion switch connected in series with the conversion inductor. During voltage regulation, the first or second conversion switch is first closed, the closed voltage regulating switch is then opened, and then the other voltage regulating switch is closed, and finally the first or second conversion switch is opened. This prevents large voltage surges during the conversion process and achieves a smooth voltage transition. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention is described in detail below with reference to the embodiments and accompanying drawings, in which:

[0022] Figure 1 is a circuit diagram of embodiment 1 of the present invention;

[0023] Figure 2 is a circuit diagram of embodiment 2 of the present invention;

[0024] Figure 3 is a circuit diagram of embodiment 3 of the present invention;

[0025] Figure 4 2 is a circuit diagram of embodiment 4 of the present invention. DETAILED DESCRIPTION

[0026] The specific embodiments of the present invention are further described below with reference to the accompanying drawings:

[0027] Example 1

[0028] See Figure 1 . The loaded seamless conversion transformer circuit of the present invention includes a live terminal L, a neutral terminal N, a primary coil n1 connected between the live terminal L and the neutral terminal N, and a secondary coil n2 connected to the load. The primary coil n1 has a plurality of voltage regulating taps connected to the live terminal, and each voltage regulating tap is connected in series with a voltage regulating switch between the live terminal, namely, voltage regulating switches K1, K2, K3, ... Kn. The primary coil is also provided with a conversion tap, and a conversion circuit is connected in series between the conversion tap and the neutral terminal. The conversion circuit includes a first conversion circuit and / or a second conversion circuit. The first conversion circuit includes a conversion resistor Rs and a first conversion switch Ks1 connected in series with the conversion resistor Rs; the second conversion circuit includes a conversion inductor Ls and a second conversion switch Ks2 connected in series with the conversion inductor.

[0029] The first conversion circuit and the second conversion circuit can be selected according to actual needs during operation. Only the first conversion circuit can be set, only the second conversion circuit can be set, or both the first conversion circuit and the second conversion circuit can be set.

[0030] When the conversion circuit includes a first conversion circuit and a second conversion circuit, the second conversion circuit is connected in parallel with the first conversion circuit.

[0031] In this specific embodiment, the on-load seamless transfer and voltage transformation circuit further includes a first selection switch Ks4 and a second selection switch Ks3, wherein the first selection switch Ks4 is connected in series between the conversion circuit and the neutral terminal, and the second selection switch Ks3 is connected in series between the conversion circuit and the live terminal.

[0032] In this specific embodiment, to enable the on-load seamless voltage-transformer circuit to switch between voltage-regulating and non-voltage-regulating states, the on-load seamless voltage-transformer circuit further includes a state-change switch KM1 connected to the live terminal. The state-change switch KM1 is connected in parallel with the secondary coil n2. Of course, the state-change switch KM1 may also be disconnected from the live terminal.

[0033] The working principle of the present invention is:

[0034] 1. During the transition from the non-voltage regulation state to the voltage regulation state, the first selector switch Ks4 must first be closed, and the first transfer switch Ks1 or the second transfer switch Ks2 must also be closed simultaneously to conduct the first or second conversion circuit. Once conduction is confirmed, the state transfer switch KM1 is opened. Once conduction is confirmed, one of the voltage regulation switches K1 to Kn is closed. The specific voltage regulation switch to be closed is determined based on the actual voltage regulation required, and only one voltage regulation switch must remain closed for an extended period of time. Once conduction is confirmed, the first selector switch Ks4 and the first or second transfer switch Ks1 or Ks2, if closed, are opened.

[0035] 2. During the transition from the voltage regulation state to the non-voltage regulation state, the first selection switch Ks4 must be closed first, and the first transfer switch Ks1 or the second transfer switch Ks2 must be closed simultaneously to conduct the first conversion circuit or the second conversion circuit. After confirming conduction, the switch in the closed state among the voltage regulation switches K1 to Kn is opened. After confirming conduction, the state transfer switch KM1 is closed. After confirming conduction, the first selection switch Ks4 and the first transfer switch Ks1 or the second transfer switch Ks2 in the closed state are opened.

[0036] 3. When adjusting the voltage value in the voltage regulation state, first close the second selector switch Ks3 or the first selector switch Ks4 to connect to the live terminal L or the neutral terminal N. After confirming conduction, close the first transfer switch Ks1 or the second transfer switch Ks2 to conduct the first conversion circuit or the second conversion circuit. After confirming conduction, open the voltage regulating switches K1 to Kn that are in the closed state. After opening, all switches K1 to Kn are in the open state. After confirming that all voltage regulating switches K1 to Kn are open, close one of the voltage regulating switches K1 to Kn. The specific voltage regulating switch to be closed is determined based on the actual voltage adjustment required. If only one voltage regulating switch is in the closed state for a long time, open the first selector switch Ks4 or the second selector switch Ks3 in the closed state, and open the first transfer switch Ks1 or the second transfer switch Ks2 in the closed state.

[0037] The present invention provides a transfer tap on the primary coil, with a conversion circuit connected in series between the transfer tap and the neutral terminal. The conversion circuit includes a first conversion circuit and / or a second conversion circuit. The first conversion circuit includes a conversion resistor and a first conversion switch connected in series with the conversion resistor; the second conversion circuit includes a conversion inductor and a second conversion switch connected in series with the conversion inductor. During voltage regulation, the first or second conversion switch is first closed, the closed voltage regulating switch is then opened, and then the other voltage regulating switch is closed, and finally the first or second conversion switch is opened. This prevents large voltage surges during the conversion process and achieves a smooth voltage transition.

[0038] The on-load seamless conversion transformer circuit of the present invention can be used in a transformer device, and the transformer device has the on-load seamless conversion transformer circuit.

[0039] Example 2

[0040] Please also see Figure 2 The difference between this embodiment and the first embodiment is that the conversion circuit is directly connected to the neutral line terminal, and the first selection switch Ks4 and the second selection switch Ks3 are not provided.

[0041] Example 3

[0042] See Figure 3 . The difference between this embodiment and the first embodiment is that: this embodiment is a three-phase transformer, the conversion circuit is directly connected to the neutral line terminal, and the first selection switch Ks4 and the second selection switch Ks3 are not set. The on-load seamless conversion transformer circuit of this embodiment includes a three-phase transformer, and the three-phase transformer includes three primary coils n1, n3, and n5. One end of the three primary coils is connected together to form a connection point M, and the other end is connected to the three live wire terminals L1, L2, and L3 respectively. Each of the primary coils has a number of voltage-regulating taps, and a voltage-regulating switch is connected in series between each voltage-regulating tap and the connection point M, namely KA1, KA2...KAn, KB1, KB2...KBn, KC1, KC2...KCn; each of the primary coils is also provided with a conversion tap, and the conversion A conversion circuit is connected in series between the tap and the connection point, and the conversion circuit includes a first conversion circuit and / or a second conversion circuit. The first conversion circuit includes conversion resistors Rs1, Rs2, Rs3 and first conversion switches Ks1, Ks3, Ks5 connected in series with the conversion resistors; the second conversion circuit includes conversion inductors Ls1, Ls2, Ls3 and second conversion switches Ks2, Ks4, Ks6 connected in series with the conversion inductors; and when the conversion circuit includes the first conversion circuit and the second conversion circuit, the second conversion circuit is connected in parallel with the first conversion circuit.

[0043] The first conversion circuit and the second conversion circuit can be selected according to actual needs during operation. Only the first conversion circuit can be set, only the second conversion circuit can be set, or both the first conversion circuit and the second conversion circuit can be set.

[0044] The on-load seamless transfer transformer circuit of this embodiment can be used in a transformer device, and the transformer device has the above-mentioned on-load seamless transfer transformer circuit.

[0045] Example 4

[0046] See Figure 4. The difference between this embodiment and the third embodiment is that: the conversion circuit is arranged at the secondary coil end. The on-load seamless conversion transformer circuit of the present invention includes a three-phase transformer, and the three-phase transformer includes three secondary coils n2, n4, and n6. One end of the three secondary coils is connected to the neutral line terminal UN, and the other end is connected to the three live line terminals UA, UB, and UC respectively. Each of the secondary coils has a number of voltage-regulating taps, and a voltage-regulating switch is connected in series between each voltage-regulating tap and the neutral line, namely KA1, KA2...KAn, KB1, KB2...KBn, KC1, KC2...KCn; each of the secondary coils is also provided with a conversion tap, and the conversion tap is connected to the live line. A conversion circuit is connected in series between the neutral line terminals, and the conversion circuit includes a first conversion circuit and / or a second conversion circuit. The first conversion circuit includes conversion resistors Rs1, Rs2, Rs3 and first conversion switches Ks1, Ks3, Ks5 connected in series with the conversion resistors; the second conversion circuit includes conversion inductors Ls1, Ls2, Ls3 and second conversion switches Ks2, Ks4, Ks6 connected in series with the conversion inductors; and when the conversion circuit includes the first conversion circuit and the second conversion circuit, the second conversion circuit is connected in parallel with the first conversion circuit.

[0047] The first conversion circuit and the second conversion circuit can be selected according to actual needs during operation. Only the first conversion circuit can be set, only the second conversion circuit can be set, or both the first conversion circuit and the second conversion circuit can be set.

[0048] The on-load seamless transfer transformer circuit of this embodiment can be used in a transformer device, and the transformer device has the above-mentioned on-load seamless transfer transformer circuit.

[0049] The transformer of the present invention can be a power transformer, a voltage regulator, a voltage stabilizer, or can be electrical equipment related to transformers, power-saving equipment, and other equipment. The present invention can achieve on-load voltage regulation, including voltage step-up and step-down. During the regulation process, the voltage transitions smoothly without power outages, voltage shocks, current shocks, instantaneous overvoltage, instantaneous overcurrent, and the like. Except for changes in voltage amplitude, no other changes will occur at the load device end. Since the present invention does not experience large surge voltages and large surge currents during the regulation process, and the voltage transition is smooth, it also protects various components well, making the internal resistors, reactors, transformers, and switching elements more efficient, with lower failure rates and lower maintenance costs.

[0050] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A load-carrying seamless transfer transformer circuit, comprising a live terminal, a neutral terminal, a primary coil connected between the live and neutral terminals, and a secondary coil connected to a load, the primary coil having a plurality of voltage-regulating taps connected to the live terminal, each of the voltage-regulating taps being connected in series with a voltage-regulating switch; characterized in that: The primary coil is further provided with a conversion tap, a conversion circuit is connected in series between the conversion tap and the neutral line terminal, the conversion circuit includes a first conversion circuit and / or a second conversion circuit, the first conversion circuit includes a conversion resistor and a first conversion switch connected in series with the conversion resistor; the second conversion circuit includes a conversion inductor and a second conversion switch connected in series with the conversion inductor; The second conversion circuit is connected in parallel with the first conversion circuit; The on-load seamless conversion transformer circuit further includes: a first selection switch connected in series between the conversion circuit and the neutral terminal; a second selection switch connected in series between the conversion circuit and the live wire terminal; The on-load seamless transfer transformer circuit further includes a state transfer switch connected to the live wire end, and the state transfer switch is connected in parallel with the secondary coil.

2. A voltage transformation device, characterized in that: The transformer device comprises the on-load seamless transfer transformer circuit according to claim 1.

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