Energy-saving transformer based on parallel connection of multiple transformer bodies and control method of energy-saving transformer

Abstract

The invention discloses an energy-saving transformer based on parallel connection of multiple transformer bodies and a control method thereof.The energy-saving transformer comprises a plurality of transformer body units, an intelligent control unit, a load monitoring module and a temperature sensor, and a high-voltage winding of each transformer body unit is connected with a first bus through a first control switch; the low-voltage winding of each transformer body unit is connected with the second bus through the second control switch, the intelligent control unit is connected with the first switch group, the second switch group, the load monitoring module and the temperature sensor, the load monitoring module is arranged corresponding to the second bus, and the temperature sensor is arranged on each transformer body unit; according to the invention, when the load is light, most of the transformer body units are in a power-off state, so that the overall no-load loss of the transformer is greatly reduced; along with the increase of the load, more transformer body units are gradually invested, the total load is reasonably distributed, the problem that the load loss of a single high-capacity transformer is too high when the transformer is in heavy load is solved, and the comprehensive optimization of no-load loss and load loss is realized.

Description

Technical Field

[0001] This invention relates to the field of transformer technology, and specifically to an energy-saving transformer based on the parallel connection of multiple transformer bodies and its control method. Background Technology

[0002] Transformers are core equipment in power systems for transmitting and distributing electrical energy. During operation, they generate no-load losses (iron losses) and load losses (copper losses). No-load losses are the losses caused by the alternating magnetization of the iron core when the transformer is energized; these losses are constant as long as the primary side of the transformer is connected to the power supply. Load losses are the resistive losses generated by the current flowing through the windings when the transformer is under load; their magnitude is proportional to the square of the load current.

[0003] Currently, the load in the power grid exhibits significant peak-valley fluctuations. At night or during periods of light load, the load on transformers is far below their rated capacity, but the transformer's no-load loss still exists at full capacity, resulting in very low operating efficiency and significant energy waste. In existing technologies, amorphous alloy transformers are typically used to reduce losses under light loads: amorphous alloy transformers have 60%–80% lower no-load losses than traditional silicon steel transformers, but their manufacturing cost is higher, and they cannot reduce load losses.

[0004] In view of the above-mentioned defects, the inventors of this invention have finally obtained this invention after a long period of research and practice. Summary of the Invention

[0005] To address the aforementioned technical deficiencies, the present invention provides an energy-saving transformer based on multiple transformer bodies connected in parallel, comprising several transformer body units, a first switch group, a second switch group, an intelligent control unit, a load monitoring module, and temperature sensors. Each transformer body unit includes an iron core, a high-voltage winding, and a low-voltage winding. The first switch group includes several first control switches, and the second switch group includes several second control switches. The high-voltage windings of each transformer body unit are connected to a first busbar via corresponding first control switches, and the low-voltage windings of each transformer body unit are connected to a second busbar via corresponding second control switches. Each transformer body unit is connected to the power grid via the first busbar and the second busbar. The intelligent control unit is connected to both the first switch group and the second switch group. The load monitoring module is positioned corresponding to the second busbar and is connected to the intelligent control unit. Each transformer body unit is equipped with a corresponding temperature sensor, and each temperature sensor is connected to the intelligent control unit.

[0006] Preferably, the first control switch and the second control switch are vacuum contactors or solid-state switches.

[0007] Preferably, a control method for an energy-saving transformer based on multiple transformer bodies in parallel includes: The intelligent control unit sets the connection and disconnection conditions. Through real-time monitoring by the load monitoring module and the temperature sensor, the first switch group and the second switch group are controlled based on the connection and disconnection conditions to realize the connection or disconnection of the transformer body unit to the power grid.

[0008] Preferably, the load monitoring module monitors the total output load P of the transformer in real time. load Each of the temperature sensors detects the real-time temperature T of the i-th transformer body unit connected to the power grid in real time. i , i=1~N, where N is the number of transformer body units currently connected to the power grid.

[0009] Preferably, the input condition is as follows: the intelligent control unit sets an input time period, and during the input time period, Wherein, N is the number of transformer body units connected to the power grid, S is the rated capacity of a single body unit, K1 is the input coefficient, and K1 is set to 0.8 to 0.9; the intelligent control unit increases the number of transformer body units connected to the power grid.

[0010] Preferably, the input condition is: a safety threshold T is set within the intelligent control unit. max The real-time temperature T i Exceeding the safety threshold T max At that time, the intelligent control unit increases the number of transformer body units connected to the power grid.

[0011] Preferably, the resection condition is as follows: a resection time period is set within the intelligent control unit, and during the resection time period, Where N is the number of transformer core units connected to the power grid, S is the rated capacity of a single core unit, K2 is the cutoff coefficient, and K1 is set to 0.4 to 0.5; and the intelligent control unit sets a safe temperature range, the real-time temperature T i All are within the stated temperature safety range, and the intelligent control unit reduces the number of transformer body units connected to the power grid.

[0012] Preferably, when engaging or disengaging the transformer body unit, the intelligent control unit selects the transformer body unit to be engaged or disengaged, and controls the first control switch and the second control switch corresponding to the transformer body unit to close or open synchronously, thereby completing the engagement or disengagement operation.

[0013] Preferably, the switching operation is performed when the current crosses zero.

[0014] Preferably, the intelligent control unit sets a lockout period after completing the insertion or removal operation, during which the intelligent control unit prohibits new insertion or removal operations.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: Under light load, only a few transformer units are put into operation, while most transformer units are in a de-energized state, and their no-load loss is zero, thereby significantly reducing the overall no-load loss of the transformer; as the load increases, more transformer units are gradually put into operation, and the total load is reasonably distributed, avoiding the problem of excessive load loss of a single large-capacity transformer under heavy load, and achieving the comprehensive optimization of no-load loss and load loss. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the connection structure of the energy-saving transformer based on the parallel connection of multiple transformer bodies; Figure 2 This is a flowchart illustrating the control method for the energy-saving transformer based on multiple transformer bodies connected in parallel.

[0017] The numbers in the image represent: 1-Intelligent control unit; 2-Load monitoring module; 3-First busbar; 4-Second busbar. Detailed Implementation

[0018] The above-mentioned and other technical features and advantages of the present invention will be described in more detail below with reference to the accompanying drawings. Example 1

[0019] The energy-saving transformer based on multiple transformer cores in parallel according to the present invention includes several transformer core units, a first switch group, a second switch group, an intelligent control unit 1, a load monitoring module 2, and a temperature sensor. Each transformer core unit includes an iron core, a high-voltage winding, and a low-voltage winding. The first switch group includes several first control switches, and the second switch group includes several second control switches. The high-voltage winding of each transformer core unit is connected to a first busbar 3 through a corresponding first control switch, and the low-voltage winding of each transformer core unit is connected to a second busbar 4 through a corresponding second control switch. Each transformer core unit is connected to a second busbar 4 through the first control switch. Busbar 3 and busbar 4 are connected to the power grid. The intelligent control unit 1 is connected to both the first and second switch groups, thereby controlling the corresponding first and second control switches to achieve the connection and disconnection of each transformer body unit with the power grid. The load monitoring module 2 is set corresponding to the second busbar 4 to detect the total load current or power of the entire transformer. The load monitoring module 2 is connected to the intelligent control unit 1. Each transformer body unit is equipped with a corresponding temperature sensor to monitor the winding or oil surface temperature of the corresponding transformer body unit. Each temperature sensor is connected to the intelligent control unit 1.

[0020] Preferably, the first control switch and the second control switch are vacuum contactors or solid-state switches.

[0021] Each of the aforementioned transformer core units has the same or standardized rated capacity and electrical parameters. Each of the aforementioned transformer core units is an independent, complete single-phase or three-phase transformer, ensuring that it can independently perform transformation operations.

[0022] The on / off states of the first control switch and the second control switch of the same transformer body unit are synchronized through the intelligent control unit 1, ensuring that the first bus 3 and the second bus 4 are connected simultaneously when a single transformer body unit is put into operation, and disconnected simultaneously when it is disconnected.

[0023] The intelligent control unit 1 has built-in control logic, which is used to calculate the number of transformer core units currently in optimal operation based on the real-time load detected by the load monitoring module 2 and the temperature of the core unit detected by the temperature sensor, and issue commands to control the corresponding switching actions to realize the dynamic switching of the transformer core units.

[0024] This invention allows for the operation of only a few transformer units under light load conditions, while most transformer units remain de-energized, resulting in zero no-load loss and significantly reducing the overall no-load loss of the transformer. As the load increases, more transformer units are gradually deployed, rationally distributing the total load and avoiding the problem of excessive load loss for a single large-capacity transformer under heavy load conditions. This achieves optimal overall performance in terms of both no-load and load losses.

[0025] Compared to traditional two-stage adjustable-capacity transformers, this invention enables stepless smooth adjustment across multiple stages (depending on the number of parallel transformer units), resulting in more precise energy-saving control. Employing a modular parallel structure, when one transformer unit fails, it can be isolated, allowing the remaining units to continue supplying power, thus improving power supply reliability and system redundancy. Load sharing and temperature rise control prevent localized overheating, contributing to an extended overall transformer lifespan. Although the initial investment may be slightly higher than traditional transformers, its superior energy-saving performance makes it suitable for applications with large load fluctuations (such as residential communities, commercial centers, and industrial parks), resulting in a short payback period and low total lifespan cost. Example 2

[0026] The control method for an energy-saving transformer based on multiple parallel transformer bodies as described in this invention includes: The intelligent control unit 1 sets up connection and disconnection conditions. Through real-time monitoring by the load monitoring module 2 and the temperature sensor, the first switch group and the second switch group are controlled based on the connection and disconnection conditions to enable or disconnect the number of transformer body units connected to the power grid.

[0027] Specifically, the load monitoring module 2 monitors the total output load P of the transformer in real time. load Each of the temperature sensors detects the real-time temperature T of the i-th transformer body unit connected to the power grid in real time. i , i=1~N, where N is the number of transformer body units currently connected to the power grid.

[0028] The input condition is as follows: the intelligent control unit 1 sets an input time period; during the input time period...

[0029] Wherein, N is the number of transformer body units connected to the power grid, S is the rated capacity of a single body unit, and K1 is the input coefficient, which is usually taken as 0.8 to 0.9; the intelligent control unit 1 increases the number of transformer body units connected to the power grid.

[0030] The intelligent control unit 1 has a set safety threshold T. max The real-time temperature T i Exceeding the safety threshold Tmax At that time, the intelligent control unit 1 increases the number of transformer body units connected to the power grid.

[0031] The resection condition is as follows: a resection time period is set within the intelligent control unit 1, and the resection occurs within the specified time period.

[0032] Where N is the number of transformer core units connected to the power grid, S is the rated capacity of a single core unit, K2 is the cutoff coefficient, typically taken as 0.4 to 0.5; and the intelligent control unit 1 has a set temperature safety range, the real-time temperature T i All are within the safe temperature range, and the intelligent control unit 1 reduces the number of transformer body units connected to the power grid.

[0033] When putting on or cutting off the transformer core unit, the intelligent control unit 1 sets a rotation strategy, such as "first-on, first-off" or "cyclic putting on and off," and selects the transformer core unit to be put on or cut off according to the preset rotation strategy. It then controls the first and second control switches corresponding to the transformer core unit to close or open synchronously, completing the putting on or cutting off operation. It is advisable to perform the putting on or cutting off operation near the current zero-crossing point to reduce inrush current and arcing.

[0034] The intelligent control unit 1 is set to a lockout period. During the lockout period after a switching operation is completed, the intelligent control unit 1 enters a temporary lockout state, prohibiting new switching operations to ensure system stability. It also has conventional protection functions such as overcurrent and overheat protection. Example 3

[0035] like Figure 1 As shown, Figure 1 This is a schematic diagram of the connection structure of the energy-saving transformer based on parallel connection of multiple transformer bodies. In a specific embodiment, the energy-saving transformer based on parallel connection of multiple transformer bodies of the present invention has a total capacity of 1000kVA and is composed of four standard transformer body units T1, T2, T3, and T4 with a rated capacity of 250kVA connected in parallel.

[0036] The high-voltage side of each transformer unit is connected to the 10kV first busbar 3 via its respective first control switches K11, K21, K31, and K41. The low-voltage side is connected to the 0.4kV second busbar 4 via its respective second control switches K12, K22, K32, and K42. All switches are intelligent vacuum contactors.

[0037] The intelligent control unit 1 monitors the total load of the second busbar 4 through current transformers and voltage transformers, i.e., the load monitoring module 2. Each transformer body unit is equipped with PT100 temperature sensors P1, P2, P3, and P4.

[0038] like Figure 2 As shown, Figure 2 This is a flowchart illustrating the control method for the energy-saving transformer based on multiple transformer bodies in parallel. The control method for the energy-saving transformer based on multiple transformer bodies in parallel according to the present invention is as follows: When the nighttime load is only 100kW, the intelligent control unit 1 only activates one of the transformer core units, such as T1, for operation. At this time, the other three transformer core units, T2, T3, and T4, are completely de-energized, and the no-load loss is only about 1 / 4 of that of a traditional 1000kVA transformer.

[0039] When the daytime load gradually increases to 600kW, the intelligent control unit 1, based on logical judgment, sequentially activates T2 and T3, enabling the three transformer units to share the load. The average load rate of each unit is approximately 80%, which is within the high-efficiency operating range.

[0040] When the midday load peak reaches 900kW, the intelligent control unit 1 activates the fourth transformer body unit T4, ensuring that all four transformer body units are equally loaded, thus preventing any unit from being overloaded.

[0041] When the load decreases and remains below 400kW, the intelligent control unit 1 sequentially disconnects one of the transformer body units, returning to the three-unit operation mode.

[0042] Through the above dynamic adjustment, the energy-saving transformer based on multiple parallel transformer bodies of the present invention always operates in the high-efficiency range, achieving a significant power-saving effect.

[0043] The above description is merely a preferred embodiment of the present invention and is illustrative rather than restrictive. Those skilled in the art will understand that many changes, modifications, and even equivalents can be made within the spirit and scope defined by the claims of the present invention, all of which will fall within the protection scope of the present invention.

Claims

1. An energy-saving transformer based on multiple transformer bodies connected in parallel, characterized in that, The system includes several transformer core units, a first switch group, a second switch group, an intelligent control unit, a load monitoring module, and temperature sensors. Each transformer core unit includes an iron core, a high-voltage winding, and a low-voltage winding. The first switch group includes several first control switches, and the second switch group includes several second control switches. The high-voltage winding of each transformer core unit is connected to a first busbar through a corresponding first control switch, and the low-voltage winding of each transformer core unit is connected to a second busbar through a corresponding second control switch. Each transformer core unit is connected to the power grid through the first busbar and the second busbar. The intelligent control unit is connected to both the first switch group and the second switch group. The load monitoring module is located corresponding to the second busbar and is connected to the intelligent control unit. Each transformer core unit is equipped with a corresponding temperature sensor, and each temperature sensor is connected to the intelligent control unit.

2. The energy-saving transformer based on multiple transformer bodies in parallel as described in claim 1, characterized in that, The first control switch and the second control switch are vacuum contactors or solid-state switches.

3. A control method for an energy-saving transformer based on multiple transformer bodies in parallel, as described in claim 1 or 2, characterized in that, include: The intelligent control unit sets the connection and disconnection conditions. Through real-time monitoring by the load monitoring module and the temperature sensor, the first switch group and the second switch group are controlled based on the connection and disconnection conditions to realize the connection or disconnection of the transformer body unit to the power grid.

4. The control method for an energy-saving transformer based on multiple transformer bodies in parallel as described in claim 3, characterized in that, The load monitoring module monitors the total output load P of the transformer in real time. load Each of the temperature sensors detects the real-time temperature T of the i-th transformer body unit connected to the power grid in real time. i , i=1~N, where N is the number of transformer body units currently connected to the power grid.

5. The control method for an energy-saving transformer based on multiple transformer bodies in parallel as described in claim 4, characterized in that, The input condition is as follows: the intelligent control unit sets an input time period; during the input time period... Wherein, N is the number of transformer body units connected to the power grid, S is the rated capacity of a single body unit, K1 is the input coefficient, and K1 is set to 0.8 to 0.9; the intelligent control unit increases the number of transformer body units connected to the power grid.

6. The control method for an energy-saving transformer based on multiple transformer bodies in parallel as described in claim 4, characterized in that, The input condition is: a safety threshold T is set within the intelligent control unit. max The real-time temperature T i Exceeding the safety threshold T max At that time, the intelligent control unit increases the number of transformer body units connected to the power grid.

7. The control method for an energy-saving transformer based on multiple transformer bodies in parallel as described in claim 4, characterized in that, The resection condition is as follows: a resection time period is set within the intelligent control unit, and the resection occurs within the specified time period. Where N is the number of transformer core units connected to the power grid, S is the rated capacity of a single core unit, K2 is the cutoff coefficient, and K1 is set to 0.4 to 0.5; and the intelligent control unit sets a safe temperature range, the real-time temperature T i All are within the stated temperature safety range, and the intelligent control unit reduces the number of transformer body units connected to the power grid.

8. The control method for an energy-saving transformer based on multiple transformer bodies in parallel as described in claim 4, characterized in that, When putting into operation or disconnecting the transformer body unit, the intelligent control unit selects the transformer body unit to be put into operation or disconnected, and controls the first control switch and the second control switch corresponding to the transformer body unit to close or open synchronously to complete the operation.

9. The control method for an energy-saving transformer based on multiple transformer bodies in parallel as described in claim 4, characterized in that, The switching on or off operation is performed when the current crosses zero.

10. The control method for an energy-saving transformer based on multiple transformer bodies in parallel as described in claim 4, characterized in that, After completing an input or output operation, the intelligent control unit sets a lockout period during which new input or output operations are prohibited.

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