Regulating module for low-voltage arm of direct-current voltage transformer, direct-current voltage transformer and low-voltage arm of direct-current voltage transformer

Abstract

The utility model belongs to the technical field of voltage transformers, and particularly relates to an adjusting module for a low-voltage arm of a direct-current voltage transformer, the direct-current voltage transformer and the low-voltage arm of the direct-current voltage transformer. An adjusting module for a low-voltage arm of a direct-current voltage transformer comprises an adjustable resistor which is used for being connected with a fixed-value resistor of the low-voltage arm in series. The resistance value adjusting range of the adjustable resistor meets the condition that the product of the equivalent resistance value and the equivalent capacitance value of the low-voltage arm can be equal to the product of the equivalent resistance value and the equivalent capacitance value of the high-voltage arm of the direct-current voltage transformer. According to the utility model, the connection relation between the adjustable resistor and the fixed-value resistor in the prior art is changed into series connection, so that the adjustment range of the equivalent resistance value of the low-voltage arm directly depends on the range of the adjustable resistor under the connection mode, and the adjustment capability of the low-voltage arm is greatly improved. The direct-current voltage transformer solves the technical problem that the adjusting capacity of the adjustable low-voltage arm of the direct-current voltage transformer in the prior art is limited.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of voltage transformer, specifically relates to a kind of adjusting module for the low-voltage arm of direct-current voltage transformer and direct-current voltage transformer and its low-voltage arm for direct-current voltage transformer. BACKGROUND

[0002] DC voltage transformer is the "link" between primary system and secondary control device, and its accuracy directly affects the safe and stable operation of DC system. In recent years, with the access of a large number of clean energy to power system, the traditional voltage transformer cannot adapt to the demand of wideband measurement of DC system in the new situation of new power system. The DC voltage transformer based on resistance-capacitance voltage division principle is widely used in DC transmission project due to its simple measurement principle, mature technology and wide measurement frequency band.

[0003] However, due to production errors, environmental temperature, stray parameters and other factors, the resistance-capacitance parameters of the DC voltage transformer based on resistance-capacitance voltage division principle will change relatively in actual operation, which will destroy the resistance-capacitance relationship of the high and low voltage arms of the DC voltage transformer and cause the measurement accuracy level to exceed the limit. Especially in actual engineering, it may cause the control device to malfunction and cause large-area power failure. Generally, in actual production, compensation needs to be made by replacing or connecting series and parallel resistors and capacitors in the low-voltage arm of the DC voltage transformer, which requires frequent disassembly and welding, resulting in increased labor cost and reduced production efficiency.

[0004] The existing Chinese patent application publication No. CN116500347A, published on July 28, 2023, discloses a resistance-capacitance matching method for DC voltage transformer. The scheme adds a resistance-capacitance matching adjusting unit to the traditional DC voltage transformer, and the resistance-capacitance matching adjusting unit is connected in parallel across the low-voltage arm of the DC voltage transformer. The resistance-capacitance matching adjusting unit includes an adjustable capacitor and an adjustable resistor connected in parallel. By adjusting the adjustable capacitor and the adjustable resistor, the resistance-capacitance parameters can be adjusted without frequent disassembly. However, in the above technical scheme, the adjustable resistor and the fixed resistor in the low-voltage arm are in parallel connection. In this case, the resistance value of the adjustable resistor needs to be higher than that of the fixed resistor. However, if the difference between the adjustable resistor and the fixed resistor is too large, the final equivalent resistance value will not change much when adjusting the adjustable resistor, which limits the adjustment ability and the adjustment range is only 5%. UTILITY MODEL CONTENTS

[0005] The utility model aims to provide an adjusting module for the low-voltage arm of direct-current voltage transformer and direct-current voltage transformer and its low-voltage arm, to solve the technical problem of limited adjustment ability of adjustable low-voltage arm of direct-current voltage transformer in the prior art.

[0006] To solve the above technical problems, the utility model provides a kind of for the technical scheme of the adjusting module of low voltage arm of direct current voltage transformer: a kind of for the adjusting module of low voltage arm of direct current voltage transformer, including adjustable resistance, the adjustable resistance is used to be connected in series with the fixed resistance of the low voltage arm, the resistance value adjustment range of the adjustable resistance satisfies: it can make the product of the equivalent resistance value and equivalent capacitance value of the low voltage arm with the product of the equivalent resistance value and equivalent capacitance value of high voltage arm of direct current voltage transformer equal.

[0007] The beneficial effects of the above technical solution are: the technical scheme of the adjusting module of low voltage arm of direct current voltage transformer of the utility model belongs to the element relationship change type invention creation.The utility model modifies the connection relationship between adjustable resistance and fixed resistance in prior art to series connection, and under such connection mode, the adjustment range of the equivalent resistance value of low voltage arm directly depends on the range of adjustable resistance, greatly improves the adjustment capability of low voltage arm.The utility model solves the technical problem of limited adjustment capability of adjustable low voltage arm of direct current voltage transformer in prior art.

[0008] Further, it further includes adjustable capacitor, and the adjustable capacitor is connected in parallel with the fixed capacitor of the low voltage arm, and the capacitance adjustment range of the adjustable capacitor satisfies: it can make the product of the equivalent resistance value and equivalent capacitance value of the low voltage arm with the product of the equivalent resistance value and equivalent capacitance value of high voltage arm equal.

[0009] The utility model further provides a kind of technical scheme of low voltage arm of direct current voltage transformer: a kind of low voltage arm of direct current voltage transformer, including fixed resistance and adjustable resistance, the fixed resistance is connected in series with the adjustable resistance, and the resistance value adjustment range of the adjustable resistance satisfies: it can make the product of the equivalent resistance value and equivalent capacitance value of the low voltage arm with the product of the equivalent resistance value and equivalent capacitance value of high voltage arm of direct current voltage transformer equal.

[0010] The beneficial effects of the above technical solution are: the technical scheme of the adjustable low voltage arm of direct current voltage transformer of the utility model belongs to the element relationship change type invention creation.The utility model modifies the connection relationship between adjustable resistance and fixed resistance in prior art to series connection, and under such connection mode, the adjustment range of the equivalent resistance value of low voltage arm directly depends on the range of adjustable resistance, greatly improves the adjustment capability of low voltage arm.The utility model solves the technical problem of limited adjustment capability of adjustable low voltage arm of direct current voltage transformer in prior art.

[0011] Further, it further includes upper electrode plate, lower electrode plate and intermediate electrode plate;The fixed resistance both ends are electrically connected with upper electrode plate and intermediate electrode plate respectively and the adjustable resistance both ends are electrically connected with intermediate electrode plate and lower electrode plate respectively, to make fixed resistance and adjustable resistance form series connection.

[0012] Further, the adjustable capacitor is connected in parallel with the fixed capacitor of the low-voltage arm, and the adjustable capacitor has a capacitance adjustment range that can make the product of the equivalent resistance value and the equivalent capacitance value of the low-voltage arm equal to the product of the equivalent resistance value and the equivalent capacitance value of the high-voltage arm.

[0013] Further, the adjustable capacitor is connected in parallel with the fixed capacitor of the low-voltage arm, and the adjustable capacitor has a capacitance adjustment range that can make the product of the equivalent resistance value and the equivalent capacitance value of the low-voltage arm equal to the product of the equivalent resistance value and the equivalent capacitance value of the high-voltage arm.

[0014] Further, a high-voltage arm connecting terminal for connecting the high-voltage arm of the DC voltage transformer is arranged on the upper electrode plate away from the intermediate electrode plate.

[0015] And / or a BNC data transmission terminal for transmitting a voltage signal is arranged on the lower electrode plate away from the intermediate electrode plate.

[0016] The utility model discloses still provides a kind of technical scheme of DC voltage transformer: a DC voltage transformer, including low-voltage arm and high-voltage arm, the low-voltage arm includes fixed resistance and adjustable resistance, the fixed resistance is connected in series with the adjustable resistance, the resistance adjustment range of the adjustable resistance satisfies: can make the product of the equivalent resistance value and the equivalent capacitance value of the low-voltage arm equal to the product of the equivalent resistance value and the equivalent capacitance value of the high-voltage arm.

[0017] The beneficial effects of the above technical scheme are: the technical scheme of the DC voltage transformer of the utility model belongs to the element relationship change type invention creation.The utility model modifies the connection relationship between adjustable resistance and fixed resistance in prior art as series connection, and under such connection mode, the adjustment range of the equivalent resistance value of low-voltage arm directly depends on the range of adjustable resistance, greatly improves the adjustment capability of low-voltage arm.The utility model solves the technical problem of limited adjustment capability of adjustable low-voltage arm of DC voltage transformer in prior art.

[0018] Further, the utility model discloses still include upper electrode plate, lower electrode plate and intermediate electrode plate, the fixed resistance both ends are connected with upper electrode plate and intermediate electrode plate respectively and the adjustable resistance both ends are connected with intermediate electrode plate and lower electrode plate respectively, so that fixed resistance and adjustable resistance form series connection.

[0019] Further, the adjustable capacitor is connected in parallel with the fixed capacitor of the low-voltage arm, and the adjustable capacitor has a capacitance adjustment range that can make the product of the equivalent resistance value and the equivalent capacitance value of the low-voltage arm equal to the product of the equivalent resistance value and the equivalent capacitance value of the high-voltage arm.

[0020] Further, an adjustable capacitor is further included; the adjustable capacitor and the fixed capacitor of the low-voltage arm are both electrically connected with the upper electrode plate and the lower electrode plate respectively, so that the adjustable capacitor and the fixed capacitor are in parallel; the adjustable capacitor has an adjustable range, which can make the product of the equivalent resistance value and the equivalent capacitance value of the low-voltage arm equal to the product of the equivalent resistance value and the equivalent capacitance value of the high-voltage arm. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is an equivalent circuit diagram of the DC voltage transformer in the embodiment of the DC voltage transformer of the utility model;

[0022] Figure 2 It is a structural schematic diagram of the DC voltage transformer in the embodiment of the DC voltage transformer of the utility model;

[0023] Figure 3 It is a low-voltage arm resistance-capacitance arrangement schematic diagram in the embodiment of the DC voltage transformer of the utility model.

[0024] Among them, 1, high-voltage arm connecting joint;2, insulating cover;3, bolt;4, upper electrode plate;5, long insulating support pipe;6, double head stud;7, intermediate electrode plate;8, short insulating support pipe;9, lower electrode plate;10, screw;11, grounding plate;12, BNC data transmission connector. DETAILED DESCRIPTION

[0025] The utility model modifies the connection relationship between adjustable resistance and fixed resistance in prior art as series connection, under such connection mode, the regulation range of the equivalent resistance value of the low-voltage arm directly depends on the range of adjustable resistance, greatly improves the regulation ability of the low-voltage arm.The utility model solves the technical problem of limited regulation ability of adjustable low-voltage arm of DC voltage transformer in prior art.

[0026] Embodiment of DC voltage transformer:

[0027] A DC voltage transformer, its equivalent circuit as Figure 1 Shown, including primary voltage divider body, secondary voltage divider module and acquisition module. Among them, primary voltage divider body is divided into high-voltage arm and low-voltage arm again, and the high-voltage arm is formed by the parallel connection of resistance R1 and capacitor C1;The low-voltage arm includes parallel-connected resistance R2 and capacitor C2, and further includes an adjusting module, the adjusting module includes adjustable resistance R x And adjustable capacitor C x , by adjusting adjustable resistance R x And adjustable capacitor C x Adjust the equivalent capacitance value R 20 And the equivalent resistance value C 20 Of the low-voltage arm to complete the resistance-capacitance parameter adjustment of the low-voltage arm, ensure R1C1=R20 C 20 The primary divider body realizes conversion from the system voltage U1 to the voltage U2 on both sides of the low-voltage arm.

[0028] The secondary divider module is also divided into a high-voltage arm and a low-voltage arm, the high-voltage arm of the secondary divider module is composed of the resistor R3 and the capacitor C3 in parallel, and the low-voltage arm of the secondary divider module is composed of the resistor R4 and the capacitor C4 in parallel. The secondary divider module realizes conversion from the voltage U2 on both sides of the low-voltage arm of the primary divider body to the voltage U3 on both sides of the low-voltage arm of the secondary divider module.

[0029] The acquisition module sends the voltage U3 output by the secondary divider module to the field station merging unit after sampling, amplifying and digital-analog converting the voltage U3.

[0030] Specifically, the method for adjusting the equivalent capacitance and the equivalent resistance of the low-voltage arm by the adjusting module to complete the adjustment of the resistance-capacitance parameters of the low-voltage arm is as follows (the low-voltage arm referred to below is the low-voltage arm of the primary divider body):

[0031] (1) Set the low-voltage arm fixed resistance R2 plus the part R x equal to the theoretical calculation value of the low-voltage arm resistance (i.e. the equivalent resistance value), denoted as R 20 , and the low-voltage arm capacitance C2 plus the part C x equal to the theoretical calculation value of the low-voltage arm capacitance (i.e. the equivalent capacitance value), denoted as C 20 . At the same time, because the adjustable resistance R x and the adjustable capacitance C x directly participate in the voltage division of the DC voltage transformer at the initial moment, the adjustable resistance R x and the adjustable capacitance C x not only can realize continuous and accurate adjustment downward or upward, but also can be flexibly selected according to different device voltage levels, different precision resistance-capacitance, error amount and other factors.

[0032] (2) Adjustment of the low-voltage arm resistance. Apply a DC voltage to the DC voltage transformer to obtain the voltage U2 borne by the low-voltage arm. If the actual voltage U2 borne by the low-voltage arm is equal to the theoretical voltage value, it means that (the theoretical division ratio), at which time no resistance adjustment is needed; if the actual voltage U2 borne by the low-voltage arm is less than the theoretical voltage value, it means that at which time the resistance value of the resistance R x connected in series with the low-voltage arm is increased until the voltage U2 borne by the low-voltage arm is equal to the theoretical voltage value; if the actual voltage U2 borne by the low-voltage arm is greater than the theoretical voltage value, it means that at which time the resistance value of the resistance R x connected in series with the low-voltage arm is decreased until the voltage U2 borne by the low-voltage arm is equal to the theoretical voltage value.

[0033] (3) Adjustment of low-voltage arm capacitance. Apply an AC voltage of working frequency to the DC voltage transformer, and obtain the voltage U2 borne by the low-voltage arm. If the effective value of the actual AC voltage borne by the low-voltage arm is equal to the theoretical voltage value, it means that (theoretical voltage division ratio), and no capacitance adjustment is needed at this time. If the effective value of the actual AC voltage borne by the low-voltage arm is less than the theoretical voltage value, it means that at this time, the capacitance of the adjustable capacitor C x connected in parallel with the low-voltage arm is reduced until the effective value of the AC voltage borne by the low-voltage arm is equal to the theoretical voltage value. If the effective value of the actual AC voltage borne by the low-voltage arm is greater than the theoretical voltage value, it means that at this time, the capacitance of the adjustable capacitor C x connected in parallel with the low-voltage arm is increased until the effective value of the AC voltage borne by the low-voltage arm is equal to the theoretical voltage value.

[0034] The low-voltage arm structure of the DC voltage transformer of the embodiment is shown in the arrangement diagram as Figure 2 and 3 The low-voltage arm comprises an upper electrode plate 4, an intermediate electrode plate 7, a lower electrode plate 9, a long insulating support tube 5, a short insulating support tube 8, a fixed resistor R2, a fixed capacitor C2, an adjustable resistor R x , an adjustable capacitor C x , a grounding plate 11, a high-voltage arm connecting terminal 1, and a BNC (Bayonet Nut Connector) data transmission terminal 12.

[0035] The inner and outer diameters of the long insulating support tube 5 and the short insulating support tube 8 are the same, and the inner diameter screw hole size is consistent with the screw hole size of the upper electrode plate 4, the intermediate electrode plate 7, and the lower electrode plate 9. At the same time, in order to ensure the insulation between the upper electrode plate 4, the intermediate electrode plate 7, and the lower electrode plate 9, the upper electrode plate 4 and the long insulating support tube 5, and the lower electrode plate 9 and the short insulating support tube 8 are fixed by bolts 3; the intermediate electrode plate 7 is connected and fixed with the whole composed of the long insulating support tube 5 and the upper electrode plate 4, and the whole composed of the short insulating support tube 8 and the lower electrode plate 9 by means of a stud 6, thereby constituting the whole low-voltage arm structure. It should be noted that Figure 3 the equivalent resistance of the two R 21 connected in parallel constitutes the fixed resistor R2.

[0036] In addition, the upper electrode plate 4 is welded with a conductive screw to form the high-voltage arm connecting terminal 1, which is connected with the high-voltage arm by means of rotating connection; the lower electrode plate 9, the grounding plate 11, and the shell of the BNC data transmission terminal 12 are reliably contacted by screws 10, thereby providing a good electromagnetic shielding environment for the BNC data transmission terminal 12; the fixed capacitor C2 and the adjustable capacitor C xThe fixed resistor R2 is also in full parallel mode and is welded between the upper electrode plate 4 and the middle electrode plate 7, and then the adjustable resistor R x The fixed resistor R2 is also in full parallel mode and is welded between the upper electrode plate 4 and the middle electrode plate 7, and then the adjustable resistor R

[0037] In other embodiments, the fixed resistor can be welded between the middle electrode plate and the lower electrode plate, and the adjustable resistor can be welded between the upper electrode plate and the middle electrode plate.

[0038] Embodiment of the low-voltage arm of the DC voltage transformer:

[0039] The low-voltage arm of the DC voltage transformer includes a fixed resistor and an adjustable resistor in series.

[0040] Embodiment of the adjusting module for the low-voltage arm of the DC voltage transformer:

[0041] The adjusting module for the low-voltage arm of the DC voltage transformer includes an adjustable resistor, which is used in series with the fixed resistor of the low-voltage arm.

[0042] The utility model has the following characteristics:

[0043] The utility model can adjust the resistance and capacitance of the low-voltage arm without repeated disassembly and welding, and can realize upward or downward adjustment of the resistance-capacitance matching relationship by adjusting the preset adjustable resistor and capacitor in combination with the theoretical voltage and actual voltage of the primary voltage divider low-voltage arm, thereby ensuring that the resistance-capacitance relationship of the high-voltage arm and the low-voltage arm of the DC voltage transformer primary voltage divider body is matched, improving the debugging efficiency and reducing the production cost.

[0044] Finally, it needs to be explained that the above is only the preferred embodiment of the present application, and is not used to limit the present application, although the present application is described in detail with reference to the foregoing embodiments, for those skilled in the art, it still can modify the technical solutions recorded in the foregoing embodiments without paying creative labor, or make equivalent replacement for part of the technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A regulating module for a low voltage arm of a DC voltage transformer, comprising an adjustable resistance, characterized in that, The adjustable resistor is connected in series with the fixed resistor of the low-voltage arm, and the adjustable resistor has an adjustable resistance value, and the adjustable resistance value is adjusted in a range such that the product of the equivalent resistance value and the equivalent capacitance value of the low-voltage arm is equal to the product of the equivalent resistance value and the equivalent capacitance value of the high-voltage arm of the DC voltage transformer.

2. The regulating module for low voltage arms of a direct voltage transformer according to claim 1, characterized in that, The adjustable capacitor is connected in parallel with the fixed capacitor of the low-voltage arm, and the adjustable capacitor has an adjustable capacitance value, and the adjustable capacitance value is adjusted in a range such that the product of the equivalent resistance value and the equivalent capacitance value of the low-voltage arm is equal to the product of the equivalent resistance value and the equivalent capacitance value of the high-voltage arm.

3. A low voltage arm of a DC voltage transformer comprising a fixed resistor and an adjustable resistor, characterized in that, The adjustable resistor is connected in series with the fixed resistor of the low-voltage arm, and the adjustable resistor has an adjustable resistance value, and the adjustable resistance value is adjusted in a range such that the product of the equivalent resistance value and the equivalent capacitance value of the low-voltage arm is equal to the product of the equivalent resistance value and the equivalent capacitance value of the high-voltage arm of the DC voltage transformer.

4. The low voltage leg of a DC voltage transformer according to claim 3, characterized in that The adjustable capacitor is connected in parallel with the fixed capacitor of the low-voltage arm, and the adjustable capacitor has an adjustable capacitance value, and the adjustable capacitance value is adjusted in a range such that the product of the equivalent resistance value and the equivalent capacitance value of the low-voltage arm is equal to the product of the equivalent resistance value and the equivalent capacitance value of the high-voltage arm.

5. The low voltage leg of a DC voltage transformer according to claim 3, characterized in that, The adjustable capacitor is connected in parallel with the fixed capacitor of the low-voltage arm, and the adjustable capacitor has an adjustable capacitance value, and the adjustable capacitance value is adjusted in a range such that the product of the equivalent resistance value and the equivalent capacitance value of the low-voltage arm is equal to the product of the equivalent resistance value and the equivalent capacitance value of the high-voltage arm.

6. The low voltage leg of a DC voltage transformer according to claim 4, characterized in that The adjustable capacitor is connected in parallel with the fixed capacitor of the low-voltage arm, and the adjustable capacitor has an adjustable capacitance value, and the adjustable capacitance value is adjusted in a range such that the product of the equivalent resistance value and the equivalent capacitance value of the low-voltage arm is equal to the product of the equivalent resistance value and the equivalent capacitance value of the high-voltage arm.

7. The low voltage leg of a DC voltage transformer according to claim 4, characterized in that The high-voltage arm connecting terminal for electrically connecting the high-voltage arm of the DC voltage transformer is arranged on the upper electrode plate away from the middle electrode plate; And / or the BNC data transmission terminal for transmitting a voltage signal is arranged on the lower electrode plate away from the middle electrode plate.

8. A DC voltage transformer comprising a low voltage arm and a high voltage arm, the low voltage arm comprising a fixed value resistor and an adjustable resistor, characterized in that, The adjustable resistor is connected in series with the fixed resistor of the low-voltage arm, and the adjustable resistor has an adjustable resistance value, and the adjustable resistance value is adjusted in a range such that the product of the equivalent resistance value and the equivalent capacitance value of the low-voltage arm is equal to the product of the equivalent resistance value and the equivalent capacitance value of the high-voltage arm of the DC voltage transformer.

9. The DC voltage transformer according to claim 8, characterized in that The adjustable capacitor is connected in parallel with the fixed capacitor of the low-voltage arm, and the adjustable capacitor has an adjustable capacitance value, and the adjustable capacitance value is adjusted in a range such that the product of the equivalent resistance value and the equivalent capacitance value of the low-voltage arm is equal to the product of the equivalent resistance value and the equivalent capacitance value of the high-voltage arm.

10. The DC voltage transformer of claim 8, characterized in that The adjustable capacitor is connected in parallel with the fixed capacitor of the low-voltage arm, and the adjustable capacitor has an adjustable capacitance value, and the adjustable capacitance value is adjusted in a range such that the product of the equivalent resistance value and the equivalent capacitance value of the low-voltage arm is equal to the product of the equivalent resistance value and the equivalent capacitance value of the high-voltage arm.

11. The DC voltage transformer according to claim 9, characterized in that The adjustable capacitor is electrically connected with the upper electrode plate and the lower electrode plate respectively at both ends of the fixed capacitor of the low-voltage arm, so that the adjustable capacitor and the fixed capacitor form a parallel connection, and the adjustable capacitor has a capacitance adjustment range that can make the product of the equivalent resistance value and the equivalent capacitance value of the low-voltage arm equal to the product of the equivalent resistance value and the equivalent capacitance value of the high-voltage arm.

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