On-load voltage regulation and control method for distribution transformer

Abstract

The invention discloses an on-load voltage regulation and control method for a distribution transformer, and the method carries out the regulation and control of the voltage at the output end of the on-load voltage regulation and control of the distribution transformer in combination with the economic operation characteristics of the highest voltage qualification rate and the optimal voltage of a power distribution transformer area, and specifically comprises the steps: carrying out the regulation and control of the voltage according to historical voltage data and photovoltaic access conditions of a target power distribution transformer area; setting a voltage upper limit setting value and a voltage lower limit setting value in the voltage regulation controller; the voltage regulation upper limit operating value and the voltage regulation lower limit operating value change along with the voltage upper limit setting value, the voltage lower limit setting value, the line load rate of the distribution transformer and the power flow direction, so that the output voltage of the on-load voltage regulation distribution transformer is the optimal voltage value and is stabilized between the voltage regulation upper limit operating value and the voltage regulation lower limit operating value; and the qualified rate of the low-voltage line is highest.

Description

Technical Field

[0001] The present invention relates to the technical field of power products, and in particular to an on-load voltage regulation method for a distribution transformer. Background Art

[0002] At present, most of the on-load voltage regulation control methods of on-load voltage regulation distribution transformers on the market are to set the upper and lower limit setting values ​​of the voltage regulation, so that the outlet voltage of the distribution transformer is stable between the upper and lower limit setting values ​​of the voltage regulation, which is not very ideal from the application effect. The line length varies, the load changes from time to time, and the line voltage changes greatly when the load is light or heavy, and even affects the voltage qualification rate. Fixing the upper and lower limits of the voltage regulation at one value can no longer meet the changing needs of the load. Especially with the continuous access of new energy in recent years, the voltage fluctuation amplitude has intensified, and the voltage qualification rate has also been declining. A new control strategy is needed. According to the changes in line load and the direction of the flow, the upper and lower limits of the voltage regulation can also change accordingly, so that the output voltage range of the distribution transformer changes with the fluctuation of the load and the direction of the flow. Summary of the invention

[0003] The object of the present invention is to provide a method for on-load voltage regulation of a distribution transformer to solve the problems in the above background.

[0004] To achieve the above object, the present invention can adopt the following technical solutions: A method for regulating and controlling on-load voltage regulation of a distribution transformer, characterized in that the output terminal voltage of the on-load voltage regulation distribution transformer is regulated in combination with the economic operation characteristics of the distribution station area with the highest voltage qualification rate and the optimal voltage. Specifically, the voltage upper limit setting value and the voltage lower limit setting value in the voltage regulation controller are set according to the historical voltage data of the target distribution station area and the photovoltaic access situation; the voltage regulation upper limit action value and the voltage regulation lower limit action value change with the change of the voltage upper limit setting value and the voltage lower limit setting value and the line load rate and the power flow direction of the distribution transformer, so that the output voltage of the on-load voltage regulation distribution transformer is the optimal voltage value and is stable between the voltage regulation upper limit action value and the voltage regulation lower limit action value, so that the low voltage line voltage qualification rate is the highest.

[0005] According to a preferred implementation mode of the present invention, when there is no new energy access or when there is new energy access but its power generation is less than the load power consumption of the substation, the voltage upper limit setting value is set to the upper limit value of the voltage qualified range, that is, +7%, and the voltage lower limit setting value is set to the lower limit value of the voltage qualified range, that is, -10%. The voltage regulation upper limit action value and the voltage regulation lower limit action value both change with the change of the load rate, and the output voltage change range of the on-load voltage regulating distribution transformer is: U sd =220 (1 + 7%) = 235.4 Uxd =220 (1-10%) =198 U sav =U sd [1-k sd (1-α)] (α≥0) U xav =U xd (1+k xd α) (α≥0) U xav ≤U M220 ≤U sav k xd <wm k sd <wm w=(U sd -U xd ) / (400 / √3) Among them U M220 is the output voltage of the on-load voltage-changing distribution transformer, U sd is the voltage upper limit setting value set in the voltage regulator controller, U xd is the voltage lower limit setting value set in the voltage regulator controller, U sav is the upper limit action value of the voltage regulation, U xav k is the lower limit action value of the voltage regulation, xd is the lower limit setting value load compensation coefficient, k sd is the upper limit setting value load compensation coefficient, α is the load rate (positive power supply), w is the voltage regulation range, and m is the voltage regulation level.

[0006] According to a preferred implementation mode of the present invention, when there is no new energy access or when there is new energy access but its power generation is less than the load power consumption of the substation, the voltage regulation upper limit action value is equal to the voltage upper limit setting value, and the voltage regulation lower limit action value increases with the increase of the voltage lower limit setting value and the load rate, and the output voltage variation range of the on-load voltage regulating distribution transformer is: U sav =U sd U xav =U xd (1+k xd α) (α≥0) U xav ≤U M220 ≤U sav k xd <wm w=(U sd -U xd ) / (400 / √3) U sd -U xd >U m Among them U M220 is the output voltage of the on-load voltage-changing distribution transformer, U sd is the voltage upper limit setting value set in the voltage regulator controller, U xd is the voltage lower limit setting value set in the voltage regulator controller, U sav is the upper limit action value of the voltage regulation, U xav is the lower limit action value of the voltage regulation, U m is the level voltage, k xd is the load compensation coefficient of the lower limit setting value, α is the load rate (positive power supply), w is the voltage regulation range, and m is the voltage regulation level.

[0007] According to a preferred embodiment of the present invention, the lower limit setting value load compensation coefficient k xd The load compensation factor (voltage value) U b Instead, the output voltage variation range of the on-load tap-changing distribution transformer is: U sav =U sd U xav =U xd + U b α (α ≥ 0) U xav ≤U M220 ≤U sav U b <U sd -U xd -U m U sd -U xd >U m Among them U b is the load compensation factor (voltage value).

[0008] According to a preferred embodiment of the present invention, when a new energy source is connected and its power generation is greater than the load power consumption of the substation, the voltage regulation lower limit action value is equal to the voltage lower limit setting value, and the voltage regulation upper limit action value decreases with the increase of the load rate. The output voltage variation range of the on-load voltage regulating distribution transformer is: U sav =U sd (1+k xd α) (α<0) U xav =U xd U xav≤U M220 ≤U sav k sd <wm w=(U sd -U xd ) / (400 / √3) U sd -U xd >U m Among them U M220 is the output voltage of the on-load voltage-changing distribution transformer, U sd is the voltage upper limit setting value set in the voltage regulator controller, U xd is the voltage lower limit setting value set in the voltage regulator controller, U sav is the upper limit action value of the voltage regulation, U xav is the lower limit action value of the voltage regulation, U m is the level voltage, k sd is the upper limit setting value load compensation coefficient, α is the load rate (electric energy reverse transmission), w is the voltage regulation range, and m is the voltage regulation level.

[0009] According to a preferred embodiment of the present invention, the upper limit setting value load compensation coefficient k sd The load compensation factor (voltage value) U b Instead, the output voltage variation range of the on-load tap-changing distribution transformer is: U sav =U sd + U b α (α<0) U xav =U xd U xav ≤U M220 ≤U sav U b <U sd -U xd -U m U sd -U xd >U m Among them U b is the load compensation factor (voltage value).

[0010] According to a preferred implementation mode of the present invention, when a new energy source is connected and its power generation is greater than the load power consumption of the substation, the voltage regulation lower limit action value is equal to the voltage lower limit setting value, the voltage regulation upper limit action value is equal to the voltage upper limit setting value, the voltage upper limit setting value minus the voltage lower limit setting value is slightly greater than the voltage regulation level voltage, and the output voltage variation range of the on-load voltage regulation distribution transformer is: U sav =U sd U xav =U xd =198 U xav ≤U M220 ≤U sav U sd -U xd >U m Among them U M220 is the output voltage of the on-load voltage-changing distribution transformer, U sd is the voltage upper limit setting value set in the voltage regulator controller, U xd is the voltage lower limit setting value set in the voltage regulator controller, U sav is the upper limit action value of the voltage regulation, U xav is the lower limit action value of the voltage regulation, U m For the level voltage.

[0011] Compared with the prior art, the beneficial effect of the present invention is that a new type of on-load voltage regulation control method is designed, and its voltage regulation upper limit action value and voltage regulation lower limit action value change with the voltage regulation upper limit setting value and voltage regulation lower limit setting value set in the voltage regulation controller and the line load rate and flow direction, so that the output voltage of the distribution transformer is maintained at the optimal value and the voltage qualification rate of the line is maximized. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a schematic diagram of voltage control of low-voltage lines in a distribution transformer area according to the present invention; Figure 2 It is a schematic diagram of the voltage drop curve of the low-voltage line in the distribution transformer area when the electric energy is transmitted positively in the present invention; Figure 3 It is a schematic diagram of the voltage drop curve of the low-voltage line in the distribution transformer area when electric energy is reversed according to the present invention. DETAILED DESCRIPTION

[0013] The present invention is further described below in conjunction with the accompanying drawings. The embodiments described below are only used to more clearly illustrate the technical solution of the present invention, are selected embodiments of the present invention, rather than all embodiments, and cannot be used to limit the scope of protection of the present invention. All other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present invention.

[0014] According to the historical voltage data of the target distribution station area and the photovoltaic access situation, the voltage upper limit setting value and the voltage lower limit setting value in the voltage regulating controller are set. The voltage upper limit action value and the voltage lower limit action value change with the voltage upper limit setting value and the voltage lower limit setting value and the distribution transformer line load rate and the flow direction, so that the output voltage of the on-load voltage regulating distribution transformer is the optimal voltage value and stabilizes between the voltage upper limit action value and the voltage lower limit action value, so that the low-voltage line voltage qualification rate is the highest. The voltage upper limit setting value and the voltage lower limit setting value are calculated according to the phase voltage, and can also be calculated according to the line voltage. The present invention mainly takes the phase voltage as an example for explanation. The qualified fluctuation range of the low-voltage line voltage of the distribution transformer is -10% to +7%, that is, the voltage qualification range is 220V×(1-10%) to 220V×(1+7%), that is, 198V to 235.4V.

[0015] See also Figure 1 When there is no new energy access or the new energy generation is less than the load power consumption of the substation, the terminal voltage of the substation is: U X220 =U M220 -ΔU X220 , the load increases and the line voltage drops ΔU X220 As a result, the transformer output voltage U M220 The lower limit action value of the voltage regulation increases accordingly, compensating for the voltage drop of the low-voltage line, making the terminal power supply voltage U X220 Maintain qualified stability; when the renewable energy generation is greater than the load power consumption of the station area, the voltage at the renewable energy access point: U X220 =U M220 -ΔU X220 When the electric energy is reversed, the reverse voltage drop is negative, and the transformer low-voltage side voltage U M220 The voltage U X220 Qualified and stable.

[0016] The on-load voltage regulation control method of the present invention dynamically adjusts the upper and lower limits of the voltage regulation action according to the actual load change and the flow direction of the station area, so that it can better fit the actual power supply status of different users to adjust the voltage and improve the voltage qualification rate of the distribution station area. The specific control method is described as follows: Scenario 1 Condition: No new energy is connected or new energy is connected but its power generation is less than the load power consumption of the station area: When the load is light, the line voltage drop is negligible because it is very small. As long as the transformer output voltage is within the range of 198V to 235.4V, the qualified rate of the low-voltage line power supply voltage in the substation area can reach 100%. Figure 2 When overloaded, if the voltage drop of the low-voltage line is less than the difference between the upper and lower limits of the voltage qualified range, that is, the line voltage drop is less than 37.4V, as long as the transformer output voltage is maintained at 235.4V (around 235.4V), the terminal voltage can be guaranteed to be qualified (235.4V-37.4V=198V), that is, the qualified rate of the low-voltage line power supply voltage in the substation area can be 100%, see Figure 2 The red curve in the figure. If the voltage drop of the entire line is greater than 37.4V, it is impossible to achieve a 100% qualified rate of the entire low-voltage line through the on-load voltage regulation distribution transformer, and the voltage qualified rate can only be maximized. Note: If the transformer output voltage is maintained at 235.4V, the on-load voltage regulation needs to be operated frequently.

[0017] Control method 1: Voltage upper limit setting value U sd Set to the upper limit of the voltage qualified range, that is, +7% (235.4V), and the lower limit setting value of the voltage is U xd Set to the lower limit of the voltage qualified range, i.e. -10% (198V), and the upper limit action value of the voltage regulation is U sav And the lower limit action value of voltage regulation U xav The output voltage of the on-load voltage-adjusting distribution transformer changes with the load rate. U sav =U sd [1-k sd (1-α)] (α≥0) U xav =U xd (1+k xd α) (α≥0) U xav ≤U M220 ≤U sav k xd <wm k sd <wm w=(U sd -U xd ) / (400 / √3) For example: voltage regulation level m=2.5%, k xd <wm select k xd =0.12, k sd <wm select k sd =0.13; When the load rate α=80%, the voltage regulator controller automatically calculates the output voltage range of the on-load voltage regulating distribution transformer: 217≤U M220 ≤229.3, lower than 217V or higher than 229.3V, the on-load voltage-changing transformer shall adjust the switch position; When the load rate α=20%, the voltage regulator controller automatically calculates the output voltage range of the on-load voltage regulating distribution transformer: 202.8≤U M220 ≤210.9, lower than 202.8V or higher than 210.9V, the on-load tap-changing transformer adjusts the switch position.

[0018] Control method 2: voltage regulation upper limit action value U sav Equal to the voltage upper limit setting value U sd , voltage regulation lower limit action value U xav With voltage lower limit setting value U xd and the load rate α increases, the voltage upper limit setting value U sd With the voltage lower limit setting value U xd The difference should be greater than the step voltage U m (If the voltage regulation level m is 2.5%, the level voltage U m is 5.5V; if the voltage regulation level m is 5%, the level voltage U m is 11V), when light load and heavy load change, the output voltage of the on-load voltage-adjusting distribution transformer is: U sav =U sd U xav =U xd (1+k xd α) (α≥0) U xav ≤U M220 ≤U sav k xd <wm w=(U sd -U xd ) / (400 / √3) U sd -U xd >U m For example: The voltage upper limit setting value U set in the voltage regulation control sd =230V, voltage lower limit setting value U xd =210V, voltage regulation level m=2.5%, k xd <wm select k xd =0.06; When the load rate α=80%, the voltage regulator controller automatically calculates the output voltage range of the on-load voltage regulating distribution transformer: 220.1≤U M220 ≤230, lower than 220.1V or higher than 230V, the on-load voltage-changing transformer shall adjust the switch position; When the load rate α=20%, the voltage regulator controller automatically calculates the output voltage range of the on-load voltage regulating distribution transformer: 212.5≤U M220 ≤230, lower than 212.5V or higher than 230V, the on-load voltage-changing transformer adjusts the switch position.

[0019] The lower limit setting value load compensation coefficient k in the above publicity xd The load compensation factor (voltage value) U b Instead, when light load and heavy load change, the output voltage change range of the on-load voltage-changing distribution transformer is: U sav =U sd U xav =U xd + U b α (α ≥ 0) U xav ≤U M220 ≤U sav U b <U sd -U xd -U m U sd -U xd >U m For example: The voltage upper limit setting value U set in the voltage regulation control sd =228V, voltage lower limit setting value U xd =215V, voltage regulation level m=2.5% i.e. level voltage U m =5.5V, U b <U sd -U xd -U m Select U b =7V; When the load rate α=80%, the voltage regulator controller automatically calculates the output voltage range of the on-load voltage regulating distribution transformer: 220.6≤U M220 ≤228, lower than 220.6V or higher than 228V, the on-load voltage-changing transformer shall adjust the switch position; When the load rate α=20%, the voltage regulator controller automatically calculates the output voltage range of the on-load voltage regulating distribution transformer: 216.4≤U M220≤228, lower than 216.4V or higher than 228V, the on-load voltage-changing transformer adjusts the switch position.

[0020] Scenario 2: When new energy is connected and its power generation is greater than the load power consumption of the substation, power is reversed: The electric energy is reversed, and the new energy access point becomes the highest point in the substation area. Because the distributed new energy is a current source, the impedance is much greater than the grid impedance, so the voltage of the entire substation area is affected by the transformer low-voltage side voltage U M220 Therefore, the power supply voltage in the substation area is still regulated by the on-load voltage regulation of the distribution transformer, and the voltage at the new energy access point is also controlled by this. If the voltage drop of the low-voltage line is less than the difference between the upper and lower limits of the voltage qualified range, that is, the line voltage drop is less than 37.4V, as long as the voltage U M220 Keep it at 198V (around 198V), the voltage of the new energy access point can be controlled below 198V+37.4V=235.4V, that is, the voltage of the entire power supply line can be qualified, see Figure 3 Yellow curve; if the line voltage drop is greater than 37.4V, it is impossible to achieve a 100% qualified rate for the entire low-voltage line through the on-load voltage regulation distribution transformer, and the qualified rate can only be maximized. Note: If the transformer output voltage is maintained at 198V, the on-load voltage regulation needs to be operated frequently.

[0021] Control method 1: Voltage lower limit setting value U xd Set to the lower limit of the voltage qualified range, i.e. -10% (198V), and the lower limit action value of the voltage regulation is U xav Equal to the voltage lower limit setting value U xd , voltage regulation upper limit action value U sav When the electric energy is reversed, the load rate α is negative. When the reverse light load or heavy load changes, the output voltage of the on-load voltage-adjusting distribution transformer is: U sav =U sd (1+k sd α) (α<0) U xav =U xd U xav ≤U M220 ≤U sav k sd <wm w=(U sd -U xd ) / (400 / √3) U sd -U xd >U m For example: The voltage upper limit setting value U set in the voltage regulation controlsd =220V, voltage lower limit setting value U xd =198V, voltage regulation level m=2.5%, k xd <wm select k xd =0.07; When the load rate α=-80%, the voltage regulator controller automatically calculates the output voltage range of the on-load voltage regulating distribution transformer: 198≤U M220 ≤207.7, lower than 198V or higher than 207.7V, the on-load voltage-changing transformer shall adjust the switch position; When the load rate α=-20%, the voltage regulator controller automatically calculates the output voltage range of the on-load voltage regulating distribution transformer: 198≤U M220 ≤216.9, lower than 198V or higher than 216.9V, the on-load voltage-changing transformer adjusts the switch position.

[0022] The lower limit setting value load compensation coefficient k in the above publicity xd The load compensation factor (voltage value) U b Instead, when light load and heavy load change, the output voltage change range of the on-load voltage-changing distribution transformer is: U sav =U sd + U b α (α<0) U xav =U xd U xav ≤U M220 ≤U sav U b <U sd -U xd -U m U sd -U xd >U m For example: The voltage upper limit setting value U set in the voltage regulation control sd =210V, voltage lower limit setting value U xd =198V, voltage regulation level m=2.5% i.e. level voltage U m =5.5V, U b <U sd -U xd -U m Select U b =6V; When the load rate α=-80%, the output voltage range of the on-load voltage-changing distribution transformer is: 198≤U M220≤205.2, lower than 198V or higher than 205.2V, the on-load voltage-changing transformer shall adjust the switch position; When the load rate α=-20%, the output voltage range of the on-load voltage-changing distribution transformer is: 198≤U M220 ≤208.8, lower than 198V or higher than 208.8V, the on-load voltage-changing transformer adjusts the switch position.

[0023] Control method 2: Voltage lower limit setting value U xd Set to the lower limit of the voltage qualified range, i.e. -10% (198V), and the lower limit action value of the voltage regulation is U xav Equal to the voltage lower limit setting value U xd , voltage regulation upper limit action value U sav Equal to the voltage upper limit setting value U sd , the voltage upper limit setting value minus the voltage lower limit setting value is slightly greater than the voltage regulation level voltage U m , the output voltage variation range of the on-load voltage-changing distribution transformer is: U sav =U sd U xav =U xd =198 U xav ≤U M220 ≤U sav U sd -U xd >U m For example: voltage regulation level m = 2.5%, that is, level voltage U m =5.5V, U sd -U xd >U m , select U sd =204V; Regardless of the reverse load rate (α<0), the output voltage of the on-load voltage-changing distribution transformer varies within the range of 198≤U M220 ≤204, lower than 198V or higher than 204V, the on-load voltage-changing transformer adjusts the switch position.

[0024] In summary, the on-load voltage regulation method of the distribution transformer of the present invention realizes the dynamic change of the upper and lower action limits of the voltage adjusted by the on-load voltage regulation gear with the load change and the flow direction, breaking the traditional on-load voltage regulation according to the static and unchanged upper and lower voltage setting values ​​to adjust the voltage. The dynamic change of the upper and lower voltage action values ​​is more in line with the actual needs of users, solves the pain points of users, and makes the voltage qualification rate reach the highest under the existing conditions.

[0025] The above is only a preferred embodiment of the present invention. It should be pointed out that for those skilled in the art, several changes and improvements can be made without departing from the technical principles of the present invention. These changes and improvements should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for regulating on-load voltage regulation of a distribution transformer, characterized in that: Combined with the economic operation characteristics of the distribution station area with the highest voltage qualification rate and the optimal voltage, the voltage at the output end of the on-load voltage-changing distribution transformer is regulated. Specifically, the voltage upper limit setting value and the voltage lower limit setting value in the voltage regulating controller are set according to the historical voltage data of the target distribution station area and the photovoltaic access situation; the voltage regulation upper limit action value and the voltage regulation lower limit action value change with the changes of the voltage upper limit setting value and the voltage lower limit setting value and the line load rate and the power flow direction of the distribution transformer, so that the output voltage of the on-load voltage-changing distribution transformer is the optimal voltage value and stabilized between the voltage regulation upper limit action value and the voltage regulation lower limit action value, so that the low-voltage line voltage qualification rate is the highest.

2. A method for regulating and controlling on-load voltage of a distribution transformer according to claim 1, characterized in that: When there is no new energy access or when there is new energy access but its power generation is less than the load power consumption of the substation, the voltage upper limit setting value is set to the upper limit of the voltage qualified range, that is, +7%, and the voltage lower limit setting value is set to the lower limit of the voltage qualified range, that is, -10%. The voltage regulation upper limit action value and the voltage regulation lower limit action value both change with the change of the load rate. The output voltage change range of the on-load voltage regulating distribution transformer is: U sd ＝220（1+7%）=235.4 U xd ＝220（1-10%）=198 IN sav =U sd [1-k sd (1-α)] (α≥0) IN xav =U xd (1+k xd α) (α≥0) IN xav ≤U M220 ≤U sav k xd <w-m k sd <w-m w=(U sd -U xd ) / (400 / √3) Among them U M220 is the output voltage of the on-load voltage-changing distribution transformer, U sd is the voltage upper limit setting value set in the voltage regulator controller, U xd is the voltage lower limit setting value set in the voltage regulator controller, U sav is the upper limit action value of the voltage regulation, U xav k is the lower limit action value of the voltage regulation, xd is the lower limit setting value load compensation coefficient, k sd is the upper limit setting value load compensation coefficient, α is the load rate (positive power supply), w is the voltage regulation range, and m is the voltage regulation level.

3. The on-load voltage regulation method for a distribution transformer according to claim 1, characterized in that: When there is no new energy access or when there is new energy access but its power generation is less than the load power consumption of the substation, the voltage regulation upper limit action value is equal to the voltage upper limit setting value, and the voltage regulation lower limit action value increases with the increase of the voltage lower limit setting value and the load rate. The output voltage variation range of the on-load voltage regulation distribution transformer is: IN sav =U sd IN xav =U xd (1+k xd α) (α≥0) IN xav ≤U M220 ≤U sav k xd <w-m w=(U sd -U xd ) / (400 / √3) IN sd -IN xd >In m Among them U M220 is the output voltage of the on-load voltage-changing distribution transformer, U sd is the voltage upper limit setting value set in the voltage regulator controller, U xd is the voltage lower limit setting value set in the voltage regulator controller, U sav is the upper limit action value of the voltage regulation, U xav is the lower limit action value of the voltage regulation, U m is the level voltage, k xd is the load compensation coefficient of the lower limit setting value, α is the load rate (positive power supply), w is the voltage regulation range, and m is the voltage regulation level.

4. A method for regulating and controlling on-load voltage of a distribution transformer according to claim 3, characterized in that: Lower limit setting value load compensation coefficient k xd The load compensation factor (voltage value) U b Instead, the output voltage variation range of the on-load tap-changing distribution transformer is: IN sav =U sd IN xav =U xd + IN b α (α≥0) IN xav ≤U M220 ≤U sav IN b <In sd -IN xd -IN m IN sd -IN xd >In m Among them U b is the load compensation factor (voltage value).

5. The on-load voltage regulation method for a distribution transformer according to claim 1, characterized in that: When new energy is connected and its power generation is greater than the load power consumption of the substation, the lower limit action value of the voltage regulation is equal to the lower limit setting value of the voltage, and the upper limit action value of the voltage regulation decreases with the increase of the load rate. The output voltage variation range of the on-load voltage regulation distribution transformer is: U sav =U sd (1+k sd a) (a<0) IN xav =U xd IN xav ≤U M220 ≤U sav k sd <w-m w=(U sd -U xd ) / (400 / √3) IN sd -IN xd >In m Among them U M220 is the output voltage of the on-load voltage-changing distribution transformer, U sd is the voltage upper limit setting value set in the voltage regulator controller, U xd is the voltage lower limit setting value set in the voltage regulator controller, U sav is the upper limit action value of the voltage regulation, U xav is the lower limit action value of the voltage regulation, U m is the level voltage, k sd is the upper limit setting value load compensation coefficient, α is the load rate (electric energy reverse transmission), w is the voltage regulation range, and m is the voltage regulation level.

6. A method for regulating and controlling on-load voltage of a distribution transformer according to claim 5, characterized in that: Upper limit setting value load compensation coefficient k sd The load compensation factor (voltage value) U b Instead, the output voltage variation range of the on-load tap-changing distribution transformer is: U sav =U sd + U b a (a<0) IN xav =U xd IN xav ≤U M220 ≤U sav IN b <In sd -IN xd -IN m IN sd -IN xd >In m Among them U b is the load compensation factor (voltage value).

7. The on-load voltage regulation method for a distribution transformer according to claim 1, characterized in that: When new energy is connected and its power generation is greater than the load power consumption of the substation, the voltage regulation lower limit action value is equal to the voltage lower limit setting value, the voltage regulation upper limit action value is equal to the voltage upper limit setting value, the voltage upper limit setting value minus the voltage lower limit setting value is slightly greater than the voltage regulation level voltage, and the output voltage variation range of the on-load voltage regulation distribution transformer is: IN sav =U sd IN xav =U xd =198 IN xav ≤U M220 ≤U sav IN sd -IN xd >In m Among them U M220 is the output voltage of the on-load voltage-changing distribution transformer, U sd is the voltage upper limit setting value set in the voltage regulator controller, U xd is the voltage lower limit setting value set in the voltage regulator controller, U sav is the upper limit action value of the voltage regulation, U xav is the lower limit action value of the voltage regulation, U m For the level voltage.

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