WO2019033335A1

WO2019033335A1 - Insulated and potted single-phase high-voltage booster transformer

Info

Publication number: WO2019033335A1
Application number: PCT/CN2017/097829
Authority: WO
Inventors: 薛军; 贾月超
Original assignee: 深圳市艾尔曼医疗电子仪器有限公司
Priority date: 2017-08-17
Filing date: 2017-08-17
Publication date: 2019-02-21

Abstract

An insulated and potted single-phase high-voltage booster transformer, comprising a primary coil (120), a secondary coil (140), and a core (150). A high-voltage capacitor (C10) is connected in parallel between the primary coil and the core or between the secondary coil and the core. The high-voltage capacitor meets the condition that the ratio of total capacitance (C1) between the core and the primary stage to the total capacitance (C2) between the core and the secondary stage is equal to the ratio of the withstand voltage (U20) of the secondary coil of the transformer with respect to the core to the withstand voltage (U10) of the primary coil with respect to the core. While ensuring insulation between the primary stage and the core and between the secondary stage and the core, the present invention avoids over-design and reduces design costs, and enables, when performing a withstand voltage test of the transformer for the secondary stage to the primary stage, voltages of the secondary and primary stages with respect to the core to be in corresponding insulation withstand voltage ranges.

Description

t Ming name: Insulated potting single-phase high-voltage step-up transformer

Technical field

[0001] The present invention relates to the field of high voltage equipment, and more particularly to an insulation potting single phase high voltage step-up transformer insulation technique.

Background technique

Insulated potting single-phase high-voltage step-up transformer is a special structure of dry-type transformer, mainly used in a variety of high-voltage equipment and high-voltage instruments. Insulation testing of transformers requires a dielectric strength test (also known as a withstand voltage test).

[0003] In the secondary to primary withstand voltage test of the transformer, the voltage distribution of the primary-to-iron core and the secondary-pair iron core of the insulated potting single-phase high-voltage step-up transformer is determined by the impedance distribution, and the insulating medium of the transformer is satisfied. For long-term working conditions, the DC resistance of the solid insulating material is much larger than the capacitive reactance. Therefore, the ratio of the voltage of the transformer primary to the core and the voltage of the secondary to the core can be considered as the capacitance and secondary pair of the primary core. The ratio of the capacitance of the iron core is inversely proportional.

[0004] In general, for the insulated potting single-phase high-voltage step-up transformer, the primary voltage is lower, and the insulation thickness of the selected skeleton is thin; the secondary voltage is much higher than the primary voltage, and the insulation thickness of the skeleton is thicker; Potting single-phase high-voltage step-up transformer, the dielectric constant of potting solid insulation material and skeleton insulation material is much higher than that of air, and the iron core is relatively stable to the primary capacitance and the core to secondary capacitance; The ratio of the core to primary capacitance and the core to secondary capacitance is not equal to the transformer secondary to core withstand voltage and primary to core withstand voltage ratio.

[0005] From the viewpoint of the insulation design of the transformer, the secondary voltage of the transformer to the primary is slightly smaller than the sum of the withstand voltage of the secondary core and the withstand voltage of the primary to the core, and the design cost is low.

[0006] For an insulated potting single-phase high-voltage step-up transformer, in the case where the sum of the withstand voltage of the secondary core and the withstand voltage of the primary core is slightly larger than the required secondary resistance of the transformer to the primary, The invention considers the use of voltage equalization technology, so that in the secondary to primary withstand voltage test of the transformer, the voltage of the secondary core and the voltage of the primary to the core are within the withstand voltage range of the corresponding insulation.

[0007] The existing insulated potting single-phase high-voltage step-up transformer design does not consider the internal insulation core of the transformer and the initial The insulation distribution between the secondary parts is designed to meet the requirements. At least one of the insulation of the primary core or the insulation of the secondary core is over-designed, the cost is higher, the transformer is more cumbersome; the design is unreasonable, the primary pair The insulation of the core or the insulation of the secondary to the core is not sufficiently insulated and is often damaged during testing or use.

[0008] Therefore, an insulated potting single-phase high-voltage step-up transformer with reasonable design and low cost is provided.

technical problem

[0009] It is an object of the present invention to provide an insulated potting single-phase high voltage step-up transformer of reasonable design and low cost.

Problem solution

Technical solution

[0010] In order to achieve the object of the present invention, the following technical solutions are provided:

[0011] An insulating potting single-phase high-voltage step-up transformer is provided, which comprises a primary coil, a secondary coil, a core, and a high voltage capacitor is connected between the primary coil and the iron core or between the secondary coil and the iron core for voltage equalization . Preferably, considering the lower primary voltage, the withstand voltage design between the primary and the iron core is generally relatively weak, and the high piezoelectric container is generally connected in parallel between the primary and the core.

[0012] A high voltage 威胁 which threatens insulation occurs between the secondary coil and the primary coil, and the present invention is between the primary coil and the iron core or between the secondary coil and the iron core in the case where the insulating structure of the transformer and the insulating material are defined. Parallel high voltage capacitors minimize electrical stress in the insulating material.

[0013] Preferably, the high voltage capacitor satisfies the condition: the ratio of the total capacitance of the core to the primary and the total capacitance of the core to the secondary is equal to the withstand voltage of the secondary coil of the transformer to the core and the withstand voltage of the primary coil to the core. ratio.

[0014] If the primary coil is opposite to the capacitor C1 between the cores, the secondary coil to the capacitor C2 between the cores, the primary coil to the core between the withstand voltage is U10, the resistance between the secondary coil and the core When the pressure is U20, the high voltage capacitor C10 with sufficient withstand voltage is connected in parallel between the primary coil and the iron core for equalization, then C10 satisfies the condition: (Cl+C10)/C2 = U20/U10.

[0015] Preferably, if the dielectric strength test voltage between the primary coil and the secondary coil is U12, the voltage of the iron core to the primary coil is: U11=C2*U12/(C1+C2+C10), the core pair The voltage of the stage coil is: U21= (C1+C10)*U12/(C1+C2+C10).

Advantageous effects of the invention

Beneficial effect [0016] Compared to the prior art, the present invention has the following advantages:

[0017] The existing insulated potting single-phase high-voltage step-up transformer design does not consider the insulation distribution between the inner insulating core of the transformer and the primary and secondary, and the design meets the requirements, at least the insulation or secondary of the primary core. One of the insulation of the iron core is over-designed, the cost is high, the transformer is cumbersome; the design is unreasonable, the primary insulation of the iron core or the insulation of the secondary core is insufficient, often damaged during testing or use. . With the present invention, over-design can be avoided to reduce the design cost while ensuring the insulation margin of the primary core insulation and the secondary core insulation. In the case of an insulated potting single-phase high-voltage step-up transformer, the present invention is in the case where the sum of the withstand voltage of the secondary core and the withstand voltage of the primary to the core is slightly larger than the required secondary resistance of the secondary to the transformer. Considering the equalization technique, the voltage of the secondary core and the voltage of the primary to the core are within the withstand voltage range of the corresponding insulation after the secondary to primary withstand voltage test of the transformer.

[0018] The embodiments of the present invention are further described in detail below with reference to the accompanying drawings.

Brief description of the drawing

DRAWINGS

1 is a schematic structural view of an insulated potting single-phase high-voltage step-up transformer according to the present invention.

2 is a circuit schematic diagram of an embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

[0021] Please refer to FIG. 1 , which is a schematic structural diagram of an insulated potting single-phase high-voltage step-up transformer according to the present invention. For ease of understanding, the single-phase high-voltage boosting of the insulating potting of the present invention is first described by using FIG. 1 before describing a specific embodiment. The principle of the transformer is described. The core 150 of the insulated potting single-phase high-voltage step-up transformer and the primary coil 120 (low voltage winding) and the secondary coil 140 (high voltage winding) are both sealed in the epoxy resin 110 in the plastic casing 130.

[0022] Referring to FIG. 1 and FIG. 2 together, the high voltage capacitor C10 of FIG. 2 is connected in parallel between the primary coil 120 (L1 in the figure) and the core 150. A currently preferred embodiment is: Insulation of the structure shown in FIG. Potting single-phase high-voltage step-up transformer, primary input voltage U1=220V~, secondary output voltage U2=9000V~, capacitance C1 between primary coil 120 and iron core 150 is 73pF, secondary coil 140 (L2 in the figure) The capacitance C2 between the iron cores 150 is 78 pF, and a high-voltage capacitor C10 having sufficient withstand voltage is connected in parallel between the primary coil 120 and the iron core 150. Pressure. The dielectric strength test voltage between the primary coil and the secondary coil is U12=23000V~. The withstand voltage between the primary coils 120 and the iron cores 150 is U10=6000V~, and the withstand voltage between the secondary coils 140 and the iron cores 150 is U 20=22500V~. C10 meets the conditions:

(Cl+C10)/C2 = U20/U 10=22500/6000

CIO = C2* U20/U10- C1

[0025] = C2*22500/6000 - C 1

[0026] = 78*22500/6000 - 73

[0027] = 219.5pF

[0028] The C10 capacitor is a 220pF, 20KVDC ultra-high voltage ceramic capacitor.

[0029] For example, the voltage equalization is not performed using the high voltage capacitor C10. When the dielectric strength test of the test voltage U12 between the primary coil and the secondary coil is 23000 ¥, the voltage of the core 150 to the primary coil 120 is: 0030] U11=C2*U12/(C1+C2)

[0031] =78*23000/(78+73)

[0032] = 11881 V~

[0033] The withstand voltage U10 between the core 150 and the core 150 is to be broken down; before the insulation breakdown of the core 150 by the primary coil 120, the voltage of the core to the secondary coil 140 is:

[0034] U21= C1*U12/(C1+C2)

[0035] =73*23000/(78+73)

[0036] = 11119V-

[0037] Below the withstand voltage U20 between the secondary coil 140 and the core 150, no breakdown; but after the insulation breakdown of the core 150 by the primary coil 120, the voltage of the core 150 to the secondary coil 140 is changed. It is 23000V~, which is higher than the withstand voltage U20 between the secondary coils 1 40 and the iron core 150, and may be broken down.

[0038] When the embodiment uses the high voltage capacitor C10吋 according to FIG. 2, the test voltage between the primary coil and the secondary coil is U12=23000V4 dielectric strength test, and the voltage of the core 150 to the primary coil 120 is:

Ul 1=C2*U12/(C1+C2+C10)

[0040] =78*23000/(78+73+220)

[0041] = 4836V-

[0042] lower than the withstand voltage U10 between the primary coil 120 and the core 150, having a large insulation margin; the core to the secondary line The voltage of circle 140 is:

U21= (C1+C10)*U12/(C1+C2+C10)

[0044] = (73+220)*23000/(78+73+220)

[0045] = 18165V-

[0046] Below the secondary withstand voltage U20 between the core, there is a large insulation margin.

The above description is only the preferred embodiment of the present invention, and the scope of the present invention is not limited thereto, and any equivalent transformation based on the technical solutions of the present invention is within the scope of the present invention.

Claims

Claim

An insulated potting single-phase high voltage step-up transformer comprising a primary coil, a secondary coil, a core, characterized in that a high voltage capacitor is connected in parallel between the primary coil and the core or between the secondary coil and the core.

The insulated potting single-phase high voltage step-up transformer according to claim 1, wherein the high voltage capacitor satisfies the condition: a ratio of a total core of the core to the primary and a total capacitance of the core to the secondary is equal to a secondary coil of the transformer. The ratio of the withstand voltage of the iron core to the withstand voltage of the primary coil to the iron core. The insulated potting single-phase high-voltage step-up transformer according to claim 1, wherein a capacitance C1 between the primary coil and the iron core, a capacitance C2 between the secondary coil and the iron core, and a primary coil to the iron core The withstand voltage is U10, and the withstand voltage between the secondary coil and the iron core is U20. When the high voltage capacitor C10 with sufficient withstand voltage is connected in parallel between the primary coil and the iron core for equalization, C10 satisfies the condition: (C1+C10 ) /C2 = U20/U10.

The insulated potting single-phase high voltage step-up transformer according to claim 3, wherein the dielectric strength test voltage between the primary coil and the secondary coil is U12, and the voltage of the iron core to the primary coil is: U11=C2* U12/(C1+C2+C10), the voltage of the iron core to the secondary coil is: U21= (C1+C10)*U12/(C1+C2+C10).