Error control circuit and method for voltage sensor in solid-sealed polar pole

Abstract

The invention discloses an error control circuit and method for a voltage sensor in a solid-sealed polar pole, and the circuit comprises a high-voltage impedance network, a low-voltage impedance network, and a coupling impedance network, and the low-voltage impedance network comprises a first fixed impedance, a first adjustable impedance, a second fixed impedance, a second adjustable impedance, and a controllable electronic switch. The high-voltage impedance network is sequentially connected with the first fixed impedance, the first adjustable impedance and the second fixed impedance in series and then grounded, the second adjustable impedance is connected with the controllable electronic switch in series and then connected with the second fixed impedance in parallel, and the controllable electronic switch is controlled by the on-off state of a vacuum arc-extinguishing chamber in the solid-sealed polar pole to execute on-off. According to the invention, not only can the basic error of the voltage sensor in the opening or closing state of the vacuum arc-extinguishing chamber be eliminated, but also the error of the voltage sensor caused by the change of the opening or closing state of the vacuum arc-extinguishing chamber can be eliminated.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical equipment. More specifically, the present invention is an error control circuit for a voltage sensor inside a solid-sealed pole column. Background Art

[0002] A solid-sealed pole column that integrates a vacuum interrupter, a voltage sensor, and an energy-taking element inside the pole column is widely used in products such as pole-mounted circuit breakers and high-voltage switchgear cabinets. The existing embedded voltage sensor uses the principle of impedance voltage division to achieve. As Figure 1 shown, the opening and closing of V in the figure represent the opening and closing of the vacuum interrupter. The voltage sensor embedded in the solid-sealed pole column includes a high-voltage impedance network TZ11, TZ21, a low-voltage impedance network TZ12, TZ22, and a coupling impedance network Z02, Z01. When the voltage sensor is set on the incoming line side of the solid-sealed pole column, one end of the high-voltage impedance network is connected to the incoming line terminal of the solid-sealed pole column, and the other end is grounded after being connected in series with the low-voltage impedance network; and one end of the coupling impedance network is connected to the outgoing line terminal of the solid-sealed pole column, and the other end is connected between the high-voltage impedance network and the low-voltage impedance network; U12 is the output voltage of the voltage sensor on the high-voltage incoming line side of the solid-sealed pole column, and its magnitude is the voltage of the low-voltage impedance network to the ground after the incoming line voltage U11 to the ground is divided by the series connection of the high-voltage impedance network and the low-voltage impedance network. When the voltage sensor is set on the outgoing line side of the solid-sealed pole column, one end of the high-voltage impedance network is connected to the outgoing line terminal of the solid-sealed pole column, and the other end is grounded after being connected in series with the low-voltage impedance network; and one end of the coupling impedance network is connected to the incoming line terminal of the solid-sealed pole column, and the other end is connected between the high-voltage impedance network and the low-voltage impedance network. U22 is the output voltage of the voltage sensor on the high-voltage outgoing line side of the solid-sealed pole column, and its magnitude is the voltage of the low-voltage impedance network to the ground after the outgoing line voltage U21 to the ground is divided by the series connection of the high-voltage impedance network and the low-voltage impedance network. However, due to regulations and voltage level constraints, etc., the impedance requirement of the coupling impedance network is very large, usually not less than 400 megohms, and the impedance of the high-voltage impedance network is usually more than ten G ohms. Therefore, whether the coupling impedance network is connected in parallel or not will affect the transformation ratio of the voltage sensor, resulting in different transformation ratios of the voltage sensor when the vacuum interrupter in the solid-sealed pole column is switched on and off, making the error range of the voltage sensor between 1% and 5% after the vacuum interrupter changes the on-off state, and the error may be even greater. Summary of the Invention

[0003] To solve the existing technical problems, the present invention innovatively provides an error control circuit for a voltage sensor inside a solid-sealed pole column, which can not only eliminate the basic error of the voltage sensor in the open or closed state of the vacuum interrupter, but also eliminate the error of the voltage sensor caused by the change of the on-off state of the vacuum interrupter.

[0004] To achieve the above technical objectives, an embodiment of the present invention discloses an error control circuit for a voltage sensor inside a solid-sealed pole column, which includes a high-voltage impedance network, a low-voltage impedance network, and a coupling impedance network. The low-voltage impedance network includes a first fixed impedance, a first adjustable impedance, a second fixed impedance, a second adjustable impedance, and a controllable electronic switch. The high-voltage impedance network is sequentially connected in series with the first fixed impedance, the first adjustable impedance, and the second fixed impedance and then grounded. The second adjustable impedance and the controllable electronic switch are connected in series and then connected in parallel with the second fixed impedance. The controllable electronic switch is controlled by the opening and closing states of the vacuum interrupter inside the solid-sealed pole column to perform opening and closing operations.

[0005] Further, for an error control circuit for a voltage sensor inside a solid-sealed pole column according to the present invention, the characteristics of the first fixed impedance, the first adjustable impedance, the second fixed impedance, and the second adjustable impedance are resistive or inductive, and the opening and closing of the controllable electronic switch follow the opening and closing of the vacuum interrupter inside the solid-sealed pole column synchronously.

[0006] Further, for an error control circuit for a voltage sensor inside a solid-sealed pole column according to the present invention, the characteristics of the first fixed impedance, the first adjustable impedance, the second fixed impedance, and the second adjustable impedance are capacitive, and the opening and closing of the controllable electronic switch follow the opening and closing of the vacuum interrupter inside the solid-sealed pole column synchronously.

[0007] An embodiment of the present invention also provides an error control method for a voltage sensor inside a solid-sealed pole column, which includes the following steps:

[0008] Configure the low-voltage impedance network. The low-voltage impedance network includes a first fixed impedance, a first adjustable impedance, a second fixed impedance, a second adjustable impedance, and a controllable electronic switch. Connect the high-voltage impedance network in series with the first fixed impedance, the first adjustable impedance, and the second fixed impedance in sequence and then ground it. Connect the second adjustable impedance and the controllable electronic switch in series and then connect them in parallel with the second fixed impedance, so that the controllable electronic switch is controlled by the opening and closing states of the vacuum interrupter inside the solid-sealed pole column to perform opening and closing operations;

[0009] Obtain the first error value of the voltage sensor when the vacuum interrupter inside the solid-sealed pole column is in the opening state;

[0010] Obtain the second error value of the voltage sensor when the vacuum interrupter inside the solid-sealed pole column is in the closing state;

[0011] Adjust the first adjustable impedance and the second adjustable impedance according to the first error value, the second error value, and the opening and closing states of the vacuum interrupter inside the solid-sealed pole column, so that the error value of the voltage sensor returns to the set value.

[0012] Further, for a method for controlling the error of a voltage sensor in a solid-sealed pole column according to the present invention, the adjusting of the first adjustable impedance and the second adjustable impedance according to the first error value, the second error value, and the on-off state of the vacuum interrupter in the solid-sealed pole column to make the error value of the voltage sensor return to the set value includes:

[0013] Determine the characteristics of the low-voltage impedance network. If the characteristics of the low-voltage impedance network are resistive or inductive, then perform the following steps:

[0014] S11: Adjust the vacuum interrupter in the solid-sealed pole column to the off state, and send the off-state signal of the vacuum interrupter to the controllable electronic switch;

[0015] S12: The controllable electronic switch receives the off-state signal of the vacuum interrupter and is controlled to disconnect;

[0016] S13: Adjust the first adjustable impedance according to the first error value to make the error value of the voltage sensor return to the set value;

[0017] S14: Adjust the vacuum interrupter in the solid-sealed pole column to the on state, and send the on-state signal of the vacuum interrupter to the controllable electronic switch;

[0018] S15: The controllable electronic switch receives the on-state signal of the vacuum interrupter and is controlled to close;

[0019] S16: Adjust the second adjustable impedance according to the second error value to make the error value of the voltage sensor return to the set value.

[0020] Further, for a method for controlling the error of a voltage sensor in a solid-sealed pole column according to the present invention, in step S13, the following steps are included:

[0021] S131: If the first error value is positive, then reduce the resistance value of the first adjustable impedance;

[0022] S132: If the first error value is negative, then increase the resistance value of the first adjustable impedance.

[0023] Further, for a method for controlling the error of a voltage sensor in a solid-sealed pole column according to the present invention, in step S16, the following steps are included:

[0024] S161: If the second error value is positive, then reduce the resistance value of the second adjustable impedance;

[0025] S162: If the second error value is negative, then increase the resistance value of the second adjustable impedance.

[0026] Further, for a method for controlling the error of a voltage sensor in a solid-sealed pole column according to the present invention, the step of adjusting the first adjustable impedance and the second adjustable impedance according to the first error value, the second error value, and the on-off state of the vacuum interrupter in the solid-sealed pole column to make the error value of the voltage sensor return to the set value further includes:

[0027] Determine the characteristics of the low-voltage impedance network. If the characteristics of the low-voltage impedance network are capacitive, then perform the following steps:

[0028] S21: Adjust the vacuum interrupter in the solid-sealed pole column to the open state, and send the open state signal of the vacuum interrupter to the controllable electronic switch;

[0029] S22: The controllable electronic switch receives the open state signal of the vacuum interrupter and is controlled to disconnect;

[0030] S23: Adjust the first adjustable impedance according to the first error value to make the error value of the voltage sensor return to the set value;

[0031] S24: Adjust the vacuum interrupter in the solid-sealed pole column to the closed state, and send the closed state signal of the vacuum interrupter to the controllable electronic switch;

[0032] S25: The controllable electronic switch receives the closed state signal of the vacuum interrupter and is controlled to close;

[0033] S26: Adjust the second adjustable impedance according to the second error value to make the error value of the voltage sensor return to the set value.

[0034] Further, for a method for controlling the error of a voltage sensor in a solid-sealed pole column according to the present invention, in step S23, the following steps are included:

[0035] S231: If the first error value is positive, increase the capacitance value of the first adjustable impedance;

[0036] S232: If the first error value is negative, decrease the capacitance value of the first adjustable impedance.

[0037] Further, for a method for controlling the error of a voltage sensor in a solid-sealed pole column according to the present invention, in step S26, the following steps are included:

[0038] S261: If the second error value is positive, increase the capacitance value of the second adjustable impedance;

[0039] S262: If the second error value is negative, decrease the capacitance value of the second adjustable impedance.

[0040] The beneficial effects of the present invention are as follows: By providing a controllable electronic switch controlled by the opening and closing states of the vacuum interrupter in the solid-sealed pole column, when the controllable electronic switch is turned off, the basic error existing in the voltage sensor itself in the opening or closing state of the vacuum interrupter can be eliminated through the first adjustable impedance; when the controllable electronic switch is closed, at this time, the second adjustable impedance and the controllable electronic switch are connected in series and then connected in parallel with the second fixed impedance, and the total impedance of this parallel circuit changes, which will change the voltage division situation of the entire low-voltage impedance network. When the controllable electronic switch is turned off, the voltage division of the low-voltage impedance network returns to the appropriate ratio in the opening state. Therefore, by adjusting the second adjustable impedance to an appropriate impedance and the controllable electronic switch to input or cut off a part of the impedance, the ratio change of the voltage sensor caused by the change of the opening and closing states of the vacuum arc extinguishing can be eliminated, and further the voltage sensor error caused by the opening and closing of the vacuum interrupter can be eliminated. Description of the Drawings

[0041] Figure 1 is the circuit schematic diagram of the voltage sensor applied in the solid-sealed pole column in the prior art;

[0042] Figure 2 is the circuit structure schematic diagram of a voltage sensor error control circuit in a solid-sealed pole column of the present invention. Detailed Embodiments

[0043] The following will explain and illustrate in detail a voltage sensor error control circuit in a solid-sealed pole column of the present invention with reference to the accompanying drawings of the specification.

[0044] As Figure 1 and in combination with Figure 2 shown, the embodiment of the present invention discloses a voltage sensor error control circuit in a solid-sealed pole column, including a high-voltage impedance network TZ11, TZ21, a low-voltage impedance network TZ12, TZ22, and a coupling impedance network Z01, Z02.

[0045] The low-voltage impedance network TZ12, TZ22 includes a first fixed impedance TZF, a first adjustable impedance TZV, a second fixed impedance ZfhF, a second adjustable impedance ZfhV, and a controllable electronic switch FHW.

[0046] The high-voltage impedance network TZ11, TZ21 is connected in series with the first fixed impedance TZF, the first adjustable impedance TZV, and the second fixed impedance ZfhF in sequence and then grounded. The second adjustable impedance ZfhV and the controllable electronic switch FHW are connected in series and then connected in parallel with the second fixed impedance ZfhF, and the controllable electronic switch FHW is controlled to open and close by the opening and closing states of the vacuum interrupter in the solid-sealed pole column.

[0047] When the controllable electronic switch FHW is closed, the second fixed impedance ZfhF and the second adjustable impedance ZfhV are in parallel, and the second fixed impedance ZfhF limits the adjustment range of the second adjustable impedance ZfhV. Taking a resistive network as an example: After parallel connection, the adjustment range of the total impedance of the two becomes smaller, and the overall impedance is more stable, without large impedance changes caused by the change of the second adjustable impedance ZfhV. When the value of the second fixed impedance ZfhF is larger, the adjustment range of the total impedance after parallel connection changes within a range closer to the minimum value of the second adjustable impedance ZfhV. When the value of the second fixed impedance ZfhF is smaller, the adjustment range of the total impedance after parallel connection will be compressed to a smaller interval and is closer to the second fixed impedance ZfhF. Therefore, the adjustment range of the total impedance can be controlled by selecting an appropriate impedance value of the second fixed impedance ZfhF so that it can meet the requirements of the error control circuit.

[0048] Figure 1 In [the figure], the situation where voltage sensors are provided on both the incoming line side B1 and the outgoing line side B2 of the vacuum interrupter in the solid-sealed pole column is shown, and the low-voltage impedance networks TZ12 and TZ22 in the present invention are used on both sides (that is, the incoming line side B1 and the outgoing line side B2 of the vacuum interrupter in the solid-sealed pole column). Of course, it can be understood that the present invention is also applicable to the situation where voltage sensors are provided on both sides but the low-voltage impedance networks TZ12 and TZ22 in the present invention are installed only on one side, or only a voltage sensor is provided on one side and the low-voltage impedance networks TZ12 and TZ22 in the present invention are correspondingly provided on this side.

[0049] The controllable electronic switch FHW in the low-voltage impedance networks TZ12 and TZ22 can be one of a transistor, a thyristor, a relay, or a contactor.

[0050] Of course, the characteristics of the low-voltage impedance networks TZ12 and TZ22 can be resistive, inductive, or capacitive. Since the resistive and inductive characteristics are reciprocal to the capacitive characteristic in terms of impedance value, the impedance size adjustment methods of the low-voltage impedance networks TZ12 and TZ22 with different characteristics are opposite. If the characteristics of the first fixed impedance TZF, the first adjustable impedance TZV, the second fixed impedance ZfhF, and the second adjustable impedance ZfhV are resistive or inductive, the opening and closing of the controllable electronic switch FHW follow the opening and closing of the vacuum interrupter in the solid-sealed pole column synchronously (that is, when the vacuum interrupter in the solid-sealed pole column opens, the controllable electronic switch FHW disconnects; when the vacuum interrupter in the solid-sealed pole column closes, the controllable electronic switch FHW closes). Similarly, if the characteristics of the first fixed impedance TZF, the first adjustable impedance TZV, the second fixed impedance ZfhF, and the second adjustable impedance ZfhV are capacitive, the opening and closing of the controllable electronic switch FHW follow the opening and closing of the vacuum interrupter in the solid-sealed pole column synchronously (that is, when the vacuum interrupter in the solid-sealed pole column opens, the controllable electronic switch FHW disconnects; when the vacuum interrupter in the solid-sealed pole column closes, the controllable electronic switch FHW closes).

[0051] In this embodiment, by providing a controllable electronic switch FHW controlled by the opening and closing states of the vacuum interrupter in the solid-sealed pole column, when the controllable electronic switch FHW is disconnected, the basic error existing in the voltage sensor itself in the opening state or closing state of the vacuum interrupter can be eliminated through the first adjustable impedance TZV; when the controllable electronic switch FHW is closed, at this time, the second adjustable impedance ZfhV and the controllable electronic switch FHW are connected in series and then in parallel with the second fixed impedance ZfhF. The total impedance of this parallel circuit changes, which will change the voltage division situation of the entire low-voltage impedance network TZ12, TZ22. When the controllable electronic switch FHW is disconnected, the voltage division of the low-voltage impedance network TZ12, TZ22 returns to the appropriate ratio in the opening state. Therefore, by adjusting the second adjustable impedance ZfhV to an appropriate impedance and the controllable electronic switch FHW to input or cut off a part of the impedance, the ratio change brought to the voltage sensor due to the change in the opening and closing states of the vacuum arc extinguishing can be eliminated, and further the voltage sensor error caused by the opening and closing of the vacuum interrupter can be eliminated.

[0052] In an embodiment of the present invention, a method for controlling the error of the voltage sensor in the solid-sealed pole column is further provided, including the following steps:

[0053] Configure the low-voltage impedance network TZ12, TZ22. The low-voltage impedance network TZ12, TZ22 includes a first fixed impedance TZF, a first adjustable impedance TZV, a second fixed impedance ZfhF, a second adjustable impedance ZfhV, and a controllable electronic switch FHW. Connect the high-voltage impedance network TZ11, TZ21 in series with the first fixed impedance TZF, the first adjustable impedance TZV, and the second fixed impedance ZfhF in sequence and then to the ground, and connect the second adjustable impedance ZfhV and the controllable electronic switch FHW in series and then in parallel with the second fixed impedance ZfhF, so that the controllable electronic switch FHW is controlled by the opening and closing states of the vacuum interrupter in the solid-sealed pole column to perform opening and closing;

[0054] Obtain the first error value of the voltage sensor in the opening state of the vacuum interrupter in the solid-sealed pole column;

[0055] Obtain the second error value of the voltage sensor in the closing state of the vacuum interrupter in the solid-sealed pole column;

[0056] According to the first error value, the second error value, and the opening and closing states of the vacuum interrupter in the solid-sealed pole column, adjust the first adjustable impedance TZV and the second adjustable impedance ZfhV so that the error value of the voltage sensor returns to the set value;

[0057] In specific adjustment, first determine the characteristics of the low-voltage impedance network TZ12, TZ22, and divide it into two cases according to the characteristics of the low-voltage impedance network TZ12, TZ22:

[0058] The first case:

[0059] If the characteristics of the low-voltage impedance networks TZ12 and TZ22 are resistive or inductive, perform the following steps:

[0060] S11: Adjust the vacuum interrupter in the solid-sealed pole column to the open state, and send the open state signal of the vacuum interrupter to the controllable electronic switch FHW;

[0061] S12: The controllable electronic switch FHW receives the open state signal of the vacuum interrupter and is controlled to disconnect;

[0062] S13: Adjust the first adjustable impedance TZV according to the first error value to make the error value of the voltage sensor return to the set value;

[0063] S14: Adjust the vacuum interrupter in the solid-sealed pole column to the closed state, and send the closed state signal of the vacuum interrupter to the controllable electronic switch FHW;

[0064] S15: The controllable electronic switch FHW receives the closed state signal of the vacuum interrupter and is controlled to close;

[0065] S16: Adjust the second adjustable impedance ZfhV according to the second error value to make the error value of the voltage sensor return to the set value.

[0066] Among them, in step S13, the following steps are included:

[0067] S131: If the first error value is positive, reduce the resistance value of the first adjustable impedance TZV to make the error value of the voltage sensor return to the set value;

[0068] S132: If the first error value is negative, increase the resistance value of the first adjustable impedance TZV to make the error value of the voltage sensor return to the set value.

[0069] Among them, in step S16, the following steps are included:

[0070] S161: If the second error value is positive, reduce the resistance value of the second adjustable impedance ZfhV to make the error value of the voltage sensor return to the set value;

[0071] S162: If the second error value is negative, increase the resistance value of the second adjustable impedance ZfhV to make the error value of the voltage sensor return to the set value.

[0072] The second case:

[0073] If the characteristics of the low-voltage impedance networks TZ12 and TZ22 are capacitive, perform the following steps:

[0074] S21: Adjust the vacuum interrupter in the solid-sealed pole column to the open state, and send the open state signal of the vacuum interrupter to the controllable electronic switch FHW;

[0075] S22: The controllable electronic switch FHW receives the opening state signal of the vacuum interrupter and is controlled to open.

[0076] S23: Adjust the first adjustable impedance TZV according to the first error value to make the error value of the voltage sensor return to the set value.

[0077] S24: Adjust the vacuum interrupter in the solid-sealed pole column to the closing state, and send the closing state signal of the vacuum interrupter to the controllable electronic switch FHW.

[0078] S25: The controllable electronic switch FHW receives the closing state signal of the vacuum interrupter and is controlled to close.

[0079] S26: Adjust the second adjustable impedance ZfhV according to the second error value to make the error value of the voltage sensor return to the set value.

[0080] Wherein, in step S23, the following steps are included:

[0081] S231: If the first error value is positive, increase the capacitance value of the first adjustable impedance TZV to make the error value of the voltage sensor return to the set value.

[0082] S232: If the first error value is negative, decrease the capacitance value of the first adjustable impedance TZV to make the error value of the voltage sensor return to the set value.

[0083] Wherein, in step S26, the following steps are included:

[0084] S261: If the second error value is positive, increase the capacitance value of the second adjustable impedance ZfhV to make the error value of the voltage sensor return to the set value.

[0085] S262: If the second error value is negative, decrease the capacitance value of the second adjustable impedance ZfhV to make the error value of the voltage sensor return to the set value.

[0086] The above set value is the error requirement value required for the sensor accuracy.

[0087] In this embodiment, a controllable electronic switch FHW controlled by the opening and closing states of the vacuum interrupter in the solid-sealed pole column is utilized. When the controllable electronic switch FHW is disconnected, the basic error existing in the voltage sensor itself in the opening or closing state of the vacuum interrupter can be eliminated through the first adjustable impedance TZV. When the controllable electronic switch FHW is closed, at this time, the second adjustable impedance ZfhV and the controllable electronic switch FHW are connected in series and then in parallel with the second fixed impedance ZfhF. The total impedance of this parallel circuit changes, which will change the voltage division situation of the entire low-voltage impedance network TZ12 and TZ22. When the controllable electronic switch FHW is disconnected, the voltage division of the low-voltage impedance network TZ12 and TZ22 returns to the appropriate ratio in the opening state. Therefore, by adjusting the second adjustable impedance ZfhV to an appropriate impedance and the controllable electronic switch FHW to input or cut off a part of the impedance, the ratio change brought to the voltage sensor due to the change in the opening and closing states of the vacuum arc extinguishing can be eliminated, and further the voltage sensor error caused by the opening and closing of the vacuum interrupter can be eliminated.

[0088] For a clearer understanding of the adjustment principle of the low-voltage impedance network, the following description is made:

[0089] Taking side B1 as an example:

[0090] Assume that the voltage of the primary side bus is U1, the secondary voltage of the voltage sensor is U2, the designed ratio is K (rated ratio, target ratio), and the error is E;

[0091] E = ((U2 * K - U1) / U1) * 100%;

[0092] U2 = (U1 * TZ12) / (TZ11 + TZ12), and TZ11 >> TZ12;

[0093] When E > 0, then U2 > U1 / K; in order to make E tend to 0, it is necessary to make U2 smaller; from the formula of U2, it can be seen that it is necessary to make TZ12 smaller. Thus, it can be known that when the error is positive, the impedance of the low-voltage impedance network needs to be made smaller. Therefore, when the characteristics of the low-voltage impedance network are resistive or inductive, the resistance value of the first adjustable impedance or the resistance value of the second adjustable impedance needs to be adjusted smaller; when the characteristics of the low-voltage impedance network are capacitive, the capacitance value of the first adjustable impedance or the capacitance value of the second adjustable impedance needs to be adjusted larger.

[0094] When E < 0, then U2 < U1 / K; in order to make E tend to 0, it is necessary to make U2 larger; from the formula of U2, it can be seen that it is necessary to make TZ12 larger. Thus, it can be known that when the error is negative, the impedance of the low-voltage impedance network needs to be made larger. Therefore, when the characteristics of the low-voltage impedance network are resistive or inductive, the resistance value of the first adjustable impedance or the resistance value of the second adjustable impedance needs to be adjusted larger; when the characteristics of the low-voltage impedance network are capacitive, the capacitance value of the first adjustable impedance or the capacitance value of the second adjustable impedance needs to be adjusted smaller.

[0095] To more clearly understand the technical effects brought by the present invention, taking the resistive network as an example, the following description is made:

[0096] As Figure 1 shown, on the premise of not adopting the low-voltage impedance networks TZ12 and TZ22 proposed by the present invention:

[0097] When V is tripped (i.e., when the vacuum interrupter in the solid-sealed pole column is tripped):

[0098] The turns ratio on the B1 side is: K1F = U11 / U12 = (TZ11 + TZ12) / TZ12;

[0099] The turns ratio on the B2 side of the switch is: K2F = U21 / U22 = (TZ21 + TZ22) / TZ22;

[0100] When V is closed:

[0101] The turns ratio on the B1 side of the switch is: K1H = U11 / U12 = (TZ11 / / Z02 + TZ12) / TZ12;

[0102] The turns ratio on the B2 side of the switch is: K2H = U21 / U22 = (TZ21 / / Z01 + TZ22) / TZ22;

[0103] TZ11 / / Z02: indicates the parallel connection of TZ11 and Z02;

[0104] TZ21 / / Z01: indicates the parallel connection of TZ21 and Z01;

[0105] Due to the constraints of relevant regulations, voltage levels, etc., the impedances Z11 and Z21 are required to be very large, usually not less than 400 megaohms, while TZ11 and TZ21 are usually several tens of G ohms. Because the parallel connection of Z01 and Z02 makes K1F not equal to K1H, and K2F not equal to K2H, there is a difference in the turns ratio of the voltage sensor when the switch is switched on and off. If the ratio error of the turns ratio during tripping meets the requirements, the ratio error during closing will exceed the standard.

[0106] As Figure 1 and combined with Figure 2 shown, after adopting the low-voltage impedance networks TZ12 and TZ22 proposed in this application:

[0107] When V is tripped (i.e., when the vacuum interrupter in the solid-sealed pole column is tripped):

[0108] The turns ratio on the B1 side is: K1F = U11 / U12 = (TZ11 + TZF + TZV + ZfhF) / (TZF + TZV + ZfhF);

[0109] The transformation ratio on the B2 side is: K2F = U21 / U22 = (TZ21 + TZF + TZV + ZfhF) / (TZF + TZV + ZfhF);

[0110] When V is switched on:

[0111] The transformation ratio on the B1 side is: K1H = U11 / U12 = (TZ11 / / Z02 + TZF + TZV + ZfhF / / ZfhV) / (TZ F + TZV + + ZfhF / / ZfhV);

[0112] ZfhF / / ZfhV represents the equivalent impedance of the parallel connection of ZfhF and ZfhV;

[0113] TZ11 / / Z02 represents the equivalent impedance of the parallel connection of TZ11 and Z02;

[0114] The transformation ratio on the B2 side is: K2H = U21 / U22 = (TZ21 / / Z01 + TZF + TZV + ZfhF / / ZfhV) / (TZF + TZV + ZfhF / / ZfhV);

[0115] ZfhF / / ZfhV represents the equivalent impedance of the parallel connection of ZfhF and ZfhV;

[0116] TZ21 / / Z01 represents the equivalent impedance of the parallel connection of TZ21 and Z01;

[0117] As can be seen from the above, the reason for the error is that when switching on and off, there are differences in the high-voltage impedance part of the voltage-dividing impedance during switching on and off. Therefore, in the present invention, a low-voltage variable impedance (i.e., ZfhV, ZfhV) controlled by switching on and off is added to the low-voltage impedance part of the voltage-dividing impedance. By controlling the opening and closing of FHW and adjusting ZfhV, ZfhV, the influence brought by the change of the high-voltage impedance can be offset, so that K1F is equal to or approximately equal to K1H, and K2F is equal to or approximately equal to K2H, maintaining the transformation ratio unchanged, or the change of the transformation ratio is within an acceptable range, thereby eliminating the accuracy error of the voltage sensor caused by switching on and off.

[0118] In the present invention, unless otherwise clearly specified and limited, terms such as "installation", "connection", "connection", "fixation" and other terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal connection of two components or the interaction relationship between two components, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0119] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0120] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and simple improvements made to the substantial content of the present invention shall be included within the protection scope of the present invention.

Claims

1. An error control circuit for a voltage sensor inside a solid-sealed pole column, comprising a high-voltage impedance network, a low-voltage impedance network, and a coupling impedance network, characterized in that: The low-voltage impedance network includes a first fixed impedance, a first adjustable impedance, a second fixed impedance, a second adjustable impedance, and a controllable electronic switch. The high-voltage impedance network is grounded after being connected in series with the first fixed impedance, the first adjustable impedance, and the second fixed impedance in sequence. The second adjustable impedance and the controllable electronic switch are connected in series and then connected in parallel with the second fixed impedance. The controllable electronic switch is controlled to open and close by the opening and closing states of the vacuum interrupter in the solid-sealed pole column.

2. The error control circuit of the voltage sensor inside the solid-sealed pole column according to claim 1, characterized in that: The characteristics of the first fixed impedance, the first adjustable impedance, the second fixed impedance, and the second adjustable impedance are resistive or inductive. The opening and closing of the controllable electronic switch follow the opening and closing of the vacuum interrupter in the solid-sealed pole column synchronously.

3. The error control circuit of the voltage sensor inside the solid-sealed pole column according to claim 1, characterized in that: The characteristics of the first fixed impedance, the first adjustable impedance, the second fixed impedance, and the second adjustable impedance are capacitive. The opening and closing of the controllable electronic switch follow the opening and closing of the vacuum interrupter in the solid-sealed pole column synchronously.

4. A method for controlling the error of a voltage sensor inside a solid-sealed pole column, characterized in that: It includes the following steps: Configure the low-voltage impedance network, which includes a first fixed impedance, a first adjustable impedance, a second fixed impedance, a second adjustable impedance, and a controllable electronic switch. Connect the high-voltage impedance network in series with the first fixed impedance, the first adjustable impedance, and the second fixed impedance in sequence and then ground it. Connect the second adjustable impedance and the controllable electronic switch in series and then connect them in parallel with the second fixed impedance, and make the controllable electronic switch be controlled to open and close by the opening and closing states of the vacuum interrupter in the solid-sealed pole column; Obtain the first error value of the voltage sensor when the vacuum interrupter in the solid-sealed pole column is in the open state; Obtain the second error value of the voltage sensor when the vacuum interrupter in the solid-sealed pole column is in the closed state; Adjust the first adjustable impedance and the second adjustable impedance according to the first error value, the second error value, and the opening and closing states of the vacuum interrupter in the solid-sealed pole column, so that the error value of the voltage sensor returns to the set value.

5. A method for controlling the error of the voltage sensor in the solid-sealed pole column according to claim 4, characterized in that: The adjusting the first adjustable impedance and the second adjustable impedance according to the first error value, the second error value, and the opening and closing states of the vacuum interrupter in the solid-sealed pole column, so that the error value of the voltage sensor returns to the set value includes: Determine the characteristics of the low-voltage impedance network. If the characteristics of the low-voltage impedance network are resistive or inductive, then execute the following steps: S11: Adjust the vacuum interrupter in the solid-sealed pole column to the open state, and send the open state signal of the vacuum interrupter to the controllable electronic switch; S12: The controllable electronic switch receives the open state signal of the vacuum interrupter and is controlled to disconnect; S13: Adjust the first adjustable impedance according to the first error value, so that the error value of the voltage sensor returns to the set value; S14: Adjust the vacuum interrupter in the solid-sealed pole column to the closed state, and send the closed state signal of the vacuum interrupter to the controllable electronic switch; S15: The controllable electronic switch receives the closed state signal of the vacuum interrupter and is controlled to close; S16: Adjust the second adjustable impedance according to the second error value, so that the error value of the voltage sensor returns to the set value.

6. A method for controlling the error of a voltage sensor in a solid-sealed pole column according to claim 5, characterized in that: In step S13, it includes the following steps: S131: If the first error value is positive, then reduce the resistance value of the first adjustable impedance; S132: If the first error value is negative, then increase the resistance value of the first adjustable impedance.

7. A method for controlling the error of a voltage sensor in a solid-sealed pole column according to claim 5, characterized in that: In step S16, it includes the following steps: S161: If the second error value is positive, decrease the resistance value of the second adjustable impedance. S162: If the second error value is negative, increase the resistance value of the second adjustable impedance.

8. A method for controlling the error of the voltage sensor inside the solid-sealed pole column according to claim 4, characterized in that: The step of adjusting the first adjustable impedance and the second adjustable impedance according to the first error value, the second error value, and the on / off states of the vacuum interrupter in the encapsulated pole column to make the error value of the voltage sensor return to the set value further includes: Determine the characteristics of the low-voltage impedance network. If the characteristics of the low-voltage impedance network are capacitive, perform the following steps: S21: Adjust the vacuum interrupter in the encapsulated pole column to the off state, and send the off-state signal of the vacuum interrupter to the controllable electronic switch. S22: The controllable electronic switch receives the off-state signal of the vacuum interrupter and is controlled to open. S23: Adjust the first adjustable impedance according to the first error value to make the error value of the voltage sensor return to the set value. S24: Adjust the vacuum interrupter in the encapsulated pole column to the on state, and send the on-state signal of the vacuum interrupter to the controllable electronic switch. S25: The controllable electronic switch receives the on-state signal of the vacuum interrupter and is controlled to close. S26: Adjust the second adjustable impedance according to the second error value to make the error value of the voltage sensor return to the set value.

9. A method for controlling the error of the voltage sensor in the solid-sealed pole column according to claim 8, characterized in that: In step S23, it includes the following steps: S231: If the first error value is positive, increase the capacitance value of the first adjustable impedance. S232: If the first error value is negative, decrease the capacitance value of the first adjustable impedance.

10. A method for controlling the error of the voltage sensor in the solid-sealed pole column according to claim 8, characterized in that: In step S26, it includes the following steps: S261: If the second error value is positive, increase the capacitance value of the second adjustable impedance. S262: If the second error value is negative, decrease the capacitance value of the second adjustable impedance.

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