On-line oil supplementing device for voltage regulating switch of power transformer

Abstract

The invention provides an on-line oil supplementing device for a power transformer voltage regulating switch. An oil gas monitoring container in the device is communicated with an oil conservator through a first oil pipe, communicated with an oil storage tank through a second oil pipe and communicated with a pressure monitor through a main gas pipe; the oil pump is arranged on the second oil pipe close to the oil storage tank; the first oil valve is arranged on the first oil pipe and close to the oil conservator; the second oil valve is arranged on the second oil pipe and is close to the oil-gas monitoring container; an exhaust valve is arranged at the other end of the branch air pipe; when the oil conservator oil capacity proportion is smaller than a first proportion, the oil pump, the first oil valve, the second oil valve and the exhaust valve are opened, after the oil capacity proportion of the oil gas monitoring container is larger than a second proportion, the exhaust valve is closed, and the oil flow rate is controlled by adjusting the output of the oil pump based on the pressure monitor until the oil conservator oil capacity proportion is larger than a third proportion; closing the oil pump and the first and second oil valves. According to the invention, on-line oil supplementation can be carried out on the voltage regulating switch under the condition that the power transformer is not powered off.

Description

Technical Field

[0001] This invention relates to the field of power transformer technology, and in particular to an online oil replenishment device for a power transformer voltage regulating switch. Background Technology

[0002] In power systems, voltage regulators play a crucial role in regulating voltage on power transformers. However, due to various reasons such as seal aging and periodic oil sampling tests, the oil level in the voltage regulator may drop during operation. Failure to replenish the oil in a timely manner may affect the normal operation of the main transformer's voltage regulator and even lead to equipment failure.

[0003] Currently, there are two main methods for replenishing oil in voltage regulator switches of power transformers: power outage replenishment and non-power outage replenishment. Power outage replenishment requires shutting down the power transformer and isolating it from the power grid, which not only affects the reliability of the power supply system but also increases maintenance costs and workload. Non-power outage replenishment overcomes the drawbacks of power outage replenishment, but the oil flow rate cannot be effectively controlled, potentially causing a large amount of gas to enter the voltage regulator switch, affecting the safe operation of the power transformer. If the flow rate is too high, it can cause the gas relay of the voltage regulator switch to trip, leading to a risk of equipment tripping.

[0004] Therefore, there is an urgent need for a new oil replenishment method for voltage regulator switches of power transformers, which can replenish oil online without interrupting power to the power transformer, ensuring the safe and stable operation of the voltage regulator switches on site, improving the power supply reliability of the power system, and reducing maintenance costs and workload. Summary of the Invention

[0005] The technical problem to be solved by the embodiments of the present invention is to provide an online oil replenishment device for a power transformer voltage regulator switch, which can replenish oil to the voltage regulator switch online without interrupting power to the power transformer, ensuring the safe and stable operation of the voltage regulator switch on site, improving the power supply reliability of the power system, and reducing maintenance costs and workload.

[0006] To address the aforementioned technical problems, this invention provides an online oil replenishment device for a power transformer voltage regulator switch. This device works in conjunction with an oil conservator pre-installed in the voltage regulator switch. The device includes an oil and gas monitoring container, an oil storage tank, an oil pump, a first oil valve, a second oil valve, an exhaust valve, a pressure monitor, a first oil pipe, a second oil pipe, a main air pipe, and branch air pipes. The oil and gas monitoring container is a transparent, sealed tank. It is connected to the oil tank through the first oil pipe, to the oil storage tank through the second oil pipe, and to the pressure monitor through the main gas pipe. The oil storage tank is a sealed tank pre-stored with a certain amount of oil. The oil pump is mounted on the second oil pipe and is located close to the oil storage tank; The first oil valve is mounted on the first oil pipe and positioned close to the oil conservator; The second oil valve is installed on the second oil pipe and is located near the oil and gas monitoring container; One end of the bronchus is connected to the middle of the main bronchus and is located between the oil and gas monitoring container and the pressure monitor, while the other end is provided with the exhaust valve. Specifically, when the oil volume ratio in the oil conservator is detected to be less than a first preset ratio, the oil pump, the first oil valve, the second oil valve, and the vent valve are turned on. After the oil volume ratio in the oil and gas monitoring container is greater than a second preset ratio, the vent valve is turned off. Furthermore, based on the pressure measured by the pressure monitor, the output of the oil pump is dynamically adjusted to control the flow rate of oil injected into the oil conservator, so as to avoid the activation of the gas relay set in the pressure regulating switch. This continues until the oil volume ratio in the oil conservator is greater than a third preset ratio, at which point the oil pump, the first oil valve, and the second oil valve are turned off.

[0007] This also includes: filters; where, The filter is installed on the second oil pipe and located between the oil pump and the second oil valve.

[0008] This also includes: a safety reflux valve and a reflux pipe; among which, One end of the return pipe is connected to the middle of the first oil pipe, and the other end is connected to the oil storage tank. The safety reflux valve is located at one end of the reflux pipe near the first oil pipe.

[0009] The output adjustment methods of the oil pump include increasing, maintaining, and decreasing; wherein, When the pressure measured by the pressure monitor is less than the lower limit pressure value, the output of the oil pump is increased and adjusted. When the pressure measured by the pressure monitor is greater than the upper limit pressure value, the output of the oil pump is reduced and adjusted. When the pressure measured by the pressure monitor is between the lower pressure limit and the upper pressure limit, the output of the oil pump is maintained.

[0010] The oil pump is a diaphragm oil pump, which consists of a drive mechanism, a diaphragm, and inlet / outlet valves; wherein, The drive mechanism drives the diaphragm to reciprocate via a connecting rod, causing the volume of the pump chamber to change periodically. When the diaphragm moves from the oil storage tank toward the oil and gas monitoring container, the volume of the pump chamber increases to create a negative pressure to draw in oil from the oil storage tank. When the diaphragm moves from the oil and gas monitoring container toward the oil storage tank, the volume of the pump chamber decreases to increase the pressure and discharge oil to the oil and gas monitoring container. The inlet and outlet valves are used to control the unidirectional flow of oil.

[0011] The oil and gas monitoring container is a sealed glass tank with a scale engraved on its outer wall to display the percentage of oil volume.

[0012] The first preset ratio is 2 / 5; the second preset ratio is 1 / 2; and the third preset ratio is 4 / 5.

[0013] The lower pressure limit is 0.03 MPa; the upper pressure limit is 0.06 MPa.

[0014] Implementing the embodiments of the present invention has the following beneficial effects: This invention activates the oil pump, first oil valve, and second oil valve to supply oil to the oil tank of the pressure regulating switch when the oil volume ratio in the oil tank is less than the initial ratio (i.e., the first preset ratio). Based on the pressure measured by the pressure monitor, the output of the oil pump is dynamically adjusted to control the flow rate of oil injected into the oil tank, thereby avoiding the activation of the gas relay set in the pressure regulating switch, until the oil volume ratio in the oil tank of the pressure regulating switch reaches the target ratio (i.e., greater than the third preset ratio). This invention not only enables online oil replenishment of the pressure regulating switch without interrupting the power transformer, but also ensures the safe and stable operation of the pressure regulating switch on site, improves the power supply reliability of the power system, and reduces maintenance costs and workload. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, obtaining other drawings based on these drawings without creative effort still falls within the scope of the present invention.

[0016] Figure 1 This is a schematic diagram of an online oil replenishment device for a power transformer voltage regulator switch provided in an embodiment of the present invention. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings.

[0018] like Figure 1 As shown in the figure, an online oil replenishment device for a power transformer voltage regulator switch is proposed in an embodiment of the present invention. It cooperates with the oil conservator TYYZ preset by the voltage regulator switch (not shown), and includes an oil and gas monitoring container YQ, an oil storage tank CYG, an oil pump GMB, a first oil valve SF1, a second oil valve YF1, an exhaust valve YF2, a pressure monitor P, a first oil pipe L1, a second oil pipe L2, a main air pipe Q1, and a branch air pipe Q2; wherein, The oil and gas monitoring container YQ is a transparent, sealed tank. It is connected to the oil conservator TYYZ via a first oil pipe L1, to the oil storage tank CYG via a second oil pipe L2, and to the pressure monitor P via a main gas pipe Q1. The top of the oil and gas monitoring container YQ has two oil inlets for installing the first oil pipe L1 and the second oil pipe L2, and a vent for connecting to the main gas pipe Q1. In one example, the oil and gas monitoring container YQ is a glass-sealed tank with a scale engraved on its outer wall to display the internal oil volume percentage, or a liquid level sensor can be installed to measure the internal oil volume percentage. To utilize the fluidity of the oil to quickly inject it into the oil conservator TYYZ, the second oil pipe L2 should be connected to the top of the oil and gas monitoring container YQ, while the first oil pipe L1 should extend as far as possible into the middle of the oil and gas monitoring container YQ, creating a height difference between the inlet and outlet points. An oil storage tank CYG is a sealed tank pre-filled with a certain amount of oil (i.e., transformer oil, not shown); in one example, an oil storage tank CYG is a sealed iron can, etc. The oil pump GMB is installed on the second oil pipe L2 and is located near the oil storage tank CYG. In one example, the oil pump GMB is a diaphragm oil pump, which consists of a drive mechanism, a diaphragm, and inlet / outlet valves. The drive mechanism drives the diaphragm to reciprocate via a connecting rod, causing the volume of the pump chamber to change periodically. When the diaphragm moves from the oil storage tank CYG toward the oil and gas monitoring container YQ, the volume of the pump chamber increases to create a negative pressure to draw in oil from the oil storage tank CYG. When the diaphragm moves from the oil and gas monitoring container YQ toward the oil storage tank CYG, the volume of the pump chamber decreases to increase the pressure and discharge oil to the oil and gas monitoring container YQ. The inlet / outlet valves are used to control the unidirectional flow of the oil, thus controlling the direction of liquid flow. The first oil valve SF1 is installed on the first oil pipe L1 and is located near the oil conservator TYYZ to control the oil flow in and out of the oil conservator TYYZ. The second oil valve YF1 is installed on the second oil pipe L2 and is located close to the oil and gas monitoring container YQ to control the oil entering and exiting the oil and gas monitoring container YQ; One end of the bronchus Q2 is connected to the middle of the main air pipe Q1 and is located between the oil and gas monitoring container YQ and the pressure monitor P. The other end is equipped with an exhaust valve YF2. At this time, air in the first oil pipe L1 and the second oil pipe L2 can be discharged through the bronchus Q2 and its exhaust valve YF2, which is beneficial to the flow of oil. Specifically, when the oil volume ratio in the oil conservator TYYZ is less than the first preset ratio (e.g., 2 / 5) as detected manually or by a level sensor, the oil pump GMB, the first oil valve SF1, the second oil valve YF1, and the vent valve YF2 are turned on. After the oil volume ratio in the oil and gas monitoring container YQ is greater than the second preset ratio (e.g., 1 / 2) as detected manually or by a level sensor, the vent valve YF2 is turned off. Furthermore, based on the pressure measured by the pressure monitor P, the output of the oil pump GMB is dynamically adjusted to control the flow rate of oil injected into the oil conservator TYYZ, so as to avoid the activation of the gas relay (not shown) set in the pressure regulating switch. This continues until the oil volume ratio in the oil conservator TYYZ is greater than the third preset ratio (e.g., 4 / 5) as detected manually or by a level sensor, at which point the oil pump GMB, the first oil valve SF1, and the second oil valve YF1 are turned off.

[0019] It should be noted that the output adjustment methods of the oil pump GMB include increasing, maintaining, and decreasing. Specifically, when the pressure measured by the pressure monitor P is lower than the lower limit pressure value (e.g., 0.03 MPa), the output of the oil pump GMB is increased; when the pressure measured by the pressure monitor P is higher than the upper limit pressure value (e.g., 0.06 MPa), the output of the oil pump GMB is decreased; when the pressure measured by the pressure monitor P is between the lower limit pressure value (e.g., 0.03 MPa) and the upper limit pressure value (e.g., 0.06 MPa), the output of the oil pump GMB is maintained, i.e., the oil speed is normal. At this time, the oil volume ratio is the ratio of the current oil volume in the container to the container volume.

[0020] Understandably, by monitoring that the oil volume ratio in the oil conservator TYYZ is less than the initial ratio (i.e., the first preset ratio), the oil pump GMB, the first oil valve SF1, and the second oil valve YF1 are activated to supply oil to the oil conservator TYYZ of the pressure regulating switch. Based on the pressure measured by the pressure monitor P, the output of the oil pump GMB is dynamically adjusted to control the flow rate of oil injected into the oil conservator TYYZ, so as to avoid the activation of the gas relay set in the pressure regulating switch, until the oil volume ratio in the oil conservator TYYZ of the pressure regulating switch reaches the target ratio (i.e., greater than the third preset ratio). This not only enables online oil replenishment of the pressure regulating switch without interrupting the power transformer, but also ensures the safe and stable operation of the pressure regulating switch on site, improves the power supply reliability of the power system, and reduces maintenance costs and workload.

[0021] In this embodiment of the invention, the device further includes a filter GLQ; wherein the filter GLQ is disposed on the second oil pipe L2 and located between the oil pump GMB and the second oil valve YF1, effectively filtering solid impurities in the oil.

[0022] In this embodiment of the invention, the device further includes: a safety return valve AQF and a return pipe L3; wherein, one end of the return pipe L3 is connected to the middle of the first oil pipe L1, and the other end is connected to the oil storage tank CYQ; the safety return valve AQF is disposed on the end of the return pipe L3 near the first oil pipe L1, and when the pressure measured by the pressure monitor P is too high, the oil flows back to the oil storage tank CYG through the safety return valve AQF, effectively ensuring the safety of oil replenishment.

[0023] The working principle of an online oil replenishment device for a power transformer voltage regulator switch in this embodiment of the invention is as follows: when the power transformer is not powered off, if the oil volume ratio in the oil conservator TYYZ is less than a first preset ratio (e.g., 2 / 5) as detected manually or by a liquid level sensor, it is determined that the online oil replenishment of the oil conservator TYYZ needs to be activated. At this time, the oil pump GMB and the second oil valve YF1 are activated to draw transformer oil from the oil storage tank CYQ and inject it into the oil and gas monitoring container YQ. At the same time, the first oil valve SF1 and the exhaust valve YF2 are activated to discharge the air in the first oil pipe L1, ensuring the normal flow of transformer oil in the future.

[0024] During the process of the oil pump GMB continuously supplying transformer oil into the oil and gas monitoring container YQ, if the oil volume ratio in the oil and gas monitoring container YQ is detected by manual means or by a liquid level sensor to be greater than the second preset ratio (e.g., 1 / 2), the exhaust valve YF2 is closed. At this time, it is necessary to consider adjusting the flow rate of transformer oil injected into the oil conservator TYYZ.

[0025] Therefore, based on the pressure measured by pressure monitor P, the output of oil pump GMB is dynamically adjusted to control the flow rate of oil injected into oil conservator TYYZ, in order to avoid the activation of the gas relay set in the pressure regulating switch. Specifically: when the pressure measured by pressure monitor P is less than the lower limit pressure value (e.g., 0.03 MPa), the output of oil pump GMB is increased; when the pressure measured by pressure monitor P is greater than the upper limit pressure value (e.g., 0.06 MPa), the output of oil pump GMB is decreased; when the pressure measured by pressure monitor P is between the lower limit pressure value (e.g., 0.03 MPa) and the upper limit pressure value (e.g., 0.06 MPa), the output of oil pump GMB is maintained, i.e., the oil flow rate is normal. In addition, the safety return valve AQF must be opened simultaneously so that when the pressure measured by pressure monitor P is too high (exceeding 0.06 MPa), the transformer oil will automatically flow back to the oil storage tank CYG through the safety return valve AQF, effectively ensuring the safety of oil replenishment.

[0026] Once the oil volume ratio in the oil conservator TYYZ is detected by manual means or a liquid level sensor to be greater than the third preset ratio (e.g., 4 / 5), the oil pump GMB and all valves, including the first oil valve SF1, the second oil valve YF1, and the safety return valve AQF, are closed, thus completing the online oil replenishment of the oil conservator TYYZ.

[0027] Implementing the embodiments of the present invention has the following beneficial effects: This invention activates the oil pump, first oil valve, and second oil valve to supply oil to the oil tank of the pressure regulating switch when the oil volume ratio in the oil tank is less than the initial ratio (i.e., the first preset ratio). Based on the pressure measured by the pressure monitor, the output of the oil pump is dynamically adjusted to control the flow rate of oil injected into the oil tank, thereby avoiding the activation of the gas relay set in the pressure regulating switch, until the oil volume ratio in the oil tank of the pressure regulating switch reaches the target ratio (i.e., greater than the third preset ratio). This invention not only enables online oil replenishment of the pressure regulating switch without interrupting the power transformer, but also ensures the safe and stable operation of the pressure regulating switch on site, improves the power supply reliability of the power system, and reduces maintenance costs and workload.

[0028] The above description discloses only preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. An on-line oil replenishing device for voltage regulating switch of power transformer, characterized in that, It cooperates with the oil pillow preset by the pressure regulating switch, including an oil gas monitoring container, an oil tank, an oil pump, a first oil valve, a second oil valve, an exhaust valve, a pressure monitor, a first oil pipe, a second oil pipe, a main gas pipe and a branch gas pipe; wherein, The oil gas monitoring container is a transparent sealed tank body, which is connected with the oil pillow through the first oil pipe, connected with the oil tank through the second oil pipe, and connected with the pressure monitor through the main gas pipe; The oil tank is a sealed tank body pre-stored with a certain amount of oil; The oil pump is arranged on the second oil pipe and close to the oil tank; The first oil valve is arranged on the first oil pipe and close to the oil pillow; The second oil valve is arranged on the second oil pipe and close to the oil gas monitoring container; One end of the branch gas pipe is connected with the middle part of the main gas pipe and located between the oil gas monitoring container and the pressure monitor, and the other end is provided with the exhaust valve; When the oil volume ratio in the oil pillow is less than the first preset ratio, the oil pump, the first oil valve, the second oil valve and the exhaust valve are opened, and when the oil volume ratio in the oil gas monitoring container is greater than the second preset ratio, the exhaust valve is closed, and further based on the pressure measured by the pressure monitor, the output of the oil pump is dynamically adjusted to control the flow rate of the oil injected into the oil pillow to avoid the action of the gas relay set by the pressure regulating switch, until the oil volume ratio in the oil pillow is greater than the third preset ratio, and the oil pump, the first oil valve and the second oil valve are closed.

2. The on-line oil replenishing device for voltage regulating switch of power transformer according to claim 1, characterized in that, Further comprising: A filter; wherein, The filter is arranged on the second oil pipe and located between the oil pump and the second oil valve.

3. The on-line oil replenishing device for voltage regulating switch of power transformer according to claim 2, characterized in that, Further comprising: A safety backflow valve and a backflow pipe; wherein, One end of the backflow pipe is connected with the middle part of the first oil pipe, and the other end is connected with the oil tank; The safety backflow valve is arranged on the end of the backflow pipe close to the first oil pipe.

4. The on-line oil replenishing device for voltage regulating switch of power transformer according to claim 3, characterized in that, The output adjustment mode of the oil pump includes increasing, maintaining and decreasing; wherein, When the pressure measured by the pressure monitor is less than the lower limit pressure value, the output of the oil pump is increased; When the pressure measured by the pressure monitor is greater than the upper limit pressure value, the output of the oil pump is decreased; When the pressure measured by the pressure monitor is between the lower limit pressure value and the upper limit pressure value, the output of the oil pump is maintained.

5. The on-line oil replenishing device for voltage regulating switch of power transformer according to claim 4, wherein, The oil pump is a diaphragm oil pump, which is composed of a driving mechanism, a diaphragm and an inlet and outlet valve; wherein, The driving mechanism drives the diaphragm to make reciprocating motion through a connecting rod, so that the volume of the pump cavity changes periodically; wherein, when the diaphragm moves from the oil tank to the oil gas monitoring container, the volume of the pump cavity increases to form negative pressure to suck oil from the oil tank; when the diaphragm moves from the oil gas monitoring container to the oil tank, the volume of the pump cavity decreases to increase the pressure to discharge oil to the oil gas monitoring container; The inlet and outlet valve is used to control the one-way flow of oil.

6. The on-line oil replenishing device for voltage regulating switch of power transformer according to claim 5, wherein, The oil and gas monitoring container is a glass sealed tank body, and a scale for displaying the proportion of oil liquid capacity is engraved on the outer wall of the tank body.

7. The on-line oil replenishing device for voltage regulating switch of power transformer according to claim 6, characterized in that, The first preset ratio is 2 / 5, the second preset ratio is 1 / 2, and the third preset ratio is 4 / 5.

8. The on-line oil replenishing device for voltage regulating switch of power transformer according to claim 7, characterized in that, The lower limit pressure value is 0.03 Mpa, and the upper limit pressure value is 0.06 Mpa.

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