阅读说明：本技术 一种自适应调节平衡系数的方法和电子设备 (Method for adaptively adjusting balance coefficient and electronic equipment ) 是由 陆洪建 杨晨 安燕杰 赵欣洋 周广伟 李宁 陈昊阳 黄欣 崔鹏 尹琦云 刘亮 于 2021-07-05 设计创作，主要内容包括：本发明提供了一种自适应调节平衡系数的方法和电子设备,所述自适应调节平衡系数的方法包括：获得换流变压器的电路数据；根据所述电路数据获得所述换流变压器的原始平衡系数；获得所述换流变压器的档位变化值；根据所述档位变化值对所述原始平衡系数进行调节,获得所述换流变压器的调节后的平衡系数；根据所述换流变压器的调节后的平衡系数,获得所述换流变压器的差动电流。根据换流变压器档位变化,自适应改变平衡系数值,能够有效避免换流变压器因档位变化引起的差动电流增大,同时又不牺牲差动保护的灵敏度,更加可靠的保证换流变压器的安全稳定运行。(The invention provides a method for adaptively adjusting a balance coefficient and electronic equipment, wherein the method for adaptively adjusting the balance coefficient comprises the following steps: obtaining circuit data of the converter transformer; obtaining an original balance coefficient of the converter transformer according to the circuit data; obtaining a gear change value of the converter transformer; adjusting the original balance coefficient according to the gear change value to obtain an adjusted balance coefficient of the converter transformer; and obtaining the differential current of the converter transformer according to the adjusted balance coefficient of the converter transformer. According to the gear change of the converter transformer, the balance coefficient value is changed in a self-adaptive mode, the increase of differential current of the converter transformer caused by the gear change can be effectively avoided, meanwhile, the sensitivity of differential protection is not sacrificed, and the safe and stable operation of the converter transformer is guaranteed more reliably.)

1. A method for adaptively adjusting a balance coefficient, comprising:

obtaining circuit data of the converter transformer;

obtaining an original balance coefficient of the converter transformer according to the circuit data;

obtaining a gear change value of the converter transformer;

adjusting the original balance coefficient according to the gear change value to obtain an adjusted balance coefficient of the converter transformer;

and obtaining the differential current of the converter transformer according to the adjusted balance coefficient of the converter transformer.

2. The method for adaptively adjusting the balance coefficient according to claim 1, wherein the original balance coefficient is adjusted according to the gear change value according to the following formula to obtain the adjusted balance coefficient of the converter transformer:

wherein, K_NewAnd K is the adjusted balance coefficient, K is the original balance coefficient, and n is the gear change value.

3. The method of adaptive adjustment of balancing coefficients of claim 1, wherein the circuit data comprises raw high side line voltage and total capacity of three phases;

the method further comprises the following steps: the high-side primary current is obtained according to the following formula:

wherein, I₁Is the primary current of the high-voltage side, S is the total capacity of the three phases, U₁Is the original high side line voltage.

4. The method of adaptively adjusting balancing coefficients of claim 3, wherein the circuit data further comprises a raw low-side line voltage;

the method further comprises the following steps: the low-voltage side primary current is obtained according to the following formula:

wherein, I₂For the low-side primary current, U₂Is the original low side rail voltage.

5. The method of adaptively adjusting balance coefficients according to claim 4, wherein the circuit data further comprises a high side current transformer transformation ratio and a low side current transformer transformation ratio;

obtaining the original balance coefficient according to the following formula:

wherein N is_LIs a stand forThe transformation ratio of the low-voltage side current transformer, N_HAnd the transformation ratio of the high-voltage side current transformer is obtained.

6. The method of adaptive adjustment of balancing coefficients according to claim 1, characterized in that the circuit data comprises original high-side line voltage, original low-side line voltage, high-side current transformer transformation ratio and low-side current transformer transformation ratio;

obtaining the original balance coefficient according to the following formula:

wherein, U₁For the original high side line voltage, U₂For the original low side line voltage, N_LIs the transformation ratio of the low-voltage side current transformer, N_HAnd the transformation ratio of the high-voltage side current transformer is obtained.

7. The method for adaptively adjusting balance coefficients according to claim 1, further comprising:

acquiring a preset balance coefficient updating threshold;

judging whether the gear change value is larger than the preset balance coefficient updating threshold value or not;

if not, the original balance coefficient is not adjusted;

the adjusting the original balance coefficient according to the gear change value to obtain the adjusted balance coefficient of the converter transformer comprises: and if the gear change value is larger than the preset balance coefficient updating threshold value, adjusting the original balance coefficient according to the gear change value to obtain the adjusted balance coefficient of the converter transformer.

8. The method of adaptively adjusting balance coefficients according to claim 4, wherein the circuit data further comprises a high side current transformer transformation ratio and a low side current transformer transformation ratio;

the differential current is obtained according to the following formula:

I_D＝I₁₂+K_new*I₂₂Wherein, in the step (A),

wherein, I_DIs the differential current, I₁₂Is a high side secondary current, I₂₂Is a low side secondary current, N_LIs the transformation ratio of the low-voltage side current transformer, N_HFor the transformation ratio of the high-side current transformer, K_NewAnd K is the adjusted balance coefficient, K is the original balance coefficient, and n is the gear change value.

9. The method for adaptively adjusting balance coefficients according to claim 1, wherein the obtaining the gear change value of the converter transformer comprises: and obtaining the gear change value of the converter transformer by connecting the tap gear acquisition device of the converter transformer to a corresponding digital acquisition node in the protection device of the converter transformer.

10. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, the processor implementing the method of adaptively adjusting balancing coefficients as claimed in any one of claims 1 to 9 when executing the computer program.

Technical Field

The invention relates to the technical field of transformers, in particular to a method for adaptively adjusting a balance coefficient and electronic equipment.

Background

At present, differential protection of a converter transformer generally uses a differential current to trigger a protection device of the converter transformer, and a calculation method of the differential current is a vector sum of a primary winding current and a secondary winding current of the converter transformer. When calculating the vector sum of the currents, the high-voltage side current needs to be converted into the low-voltage side currentCurrent (or low-side current converted into high-side current), and balance coefficient K, i.e. | I₁₂|＝|K*I₂₂[ wherein, I₁₂Is a high side secondary current, I₂₂Low side secondary current). The differential current I of the converter transformer is generally_DIs approximately equal to 0, i.e. I₁₂+K*I₂₂0. However, when the tap switch of the converter transformer performs a shifting operation, the high-side current and the low-side current do not change in proportion, and since the K value cannot be adjusted according to the gear change of the converter transformer, I may be caused_D＝I₁₂+K*I₂₂Not equal to 0, the protection device of the converter transformer is easy to misjudge. The conventional solution is to apply a differential current I_DThe action threshold value of (A) is increased, so that when the tap position of the converter transformer is adjusted, I_DAlthough the value of (A) is increased, I_DDoes not reach the action threshold. Although the method can solve the problem that the converter transformer cannot be mistakenly operated when the tap position of the converter transformer is adjusted, the sensitivity of differential protection is reduced, and the risk that a protection device refuses to operate exists.

Through the technical analysis, the prior art has the defect that the balance coefficient of the converter transformer cannot be adjusted in a self-adaptive mode according to the gear change value of the converter transformer.

Disclosure of Invention

The embodiment of the invention provides a method for adaptively adjusting a balance coefficient and electronic equipment, which aim to overcome the defect that the balance coefficient of a converter transformer in the prior art cannot be adaptively adjusted according to a gear change value of the converter transformer.

The embodiment of the invention provides a method for adaptively adjusting a balance coefficient, which comprises the following steps:

obtaining circuit data of the converter transformer;

obtaining an original balance coefficient of the converter transformer according to the circuit data;

obtaining a gear change value of the converter transformer;

adjusting the original balance coefficient according to the gear change value to obtain an adjusted balance coefficient of the converter transformer;

and obtaining the differential current of the converter transformer according to the adjusted balance coefficient of the converter transformer.

Preferably, the original balance coefficient is adjusted according to the gear change value according to the following formula, so as to obtain an adjusted balance coefficient of the converter transformer:

wherein, K_NewAnd K is the adjusted balance coefficient, K is the original balance coefficient, and n is the gear change value.

Preferably, the circuit data includes the original high side line voltage and the total capacity of three phases; the method further comprises the following steps: the high-side primary current is obtained according to the following formula:

wherein, I₁Is the primary current of the high-voltage side, S is the total capacity of the three phases, U₁Is the original high side line voltage.

Further, the circuit data also includes the original low side line voltage and the total capacity of the three phases; the method further comprises the following steps: the low-voltage side primary current is obtained according to the following formula:

wherein, I₂For the low-side primary current, U₂Is the original low side rail voltage.

Further, the circuit data further comprises a high-voltage side current transformer transformation ratio and a low-voltage side current transformer transformation ratio;

obtaining the original balance coefficient according to the following formula:

wherein N is_LIs the transformation ratio of the low-voltage side current transformer, N_HAnd the transformation ratio of the high-voltage side current transformer is obtained.

Preferably, the circuit data comprises an original high-side line voltage, an original low-side line voltage, a high-side current transformer transformation ratio and a low-side current transformer transformation ratio;

obtaining the original balance coefficient according to the following formula:

wherein, U₁For the original high side line voltage, U₂For the original low side line voltage, N_LIs the transformation ratio of the low-voltage side current transformer, N_HAnd the transformation ratio of the high-voltage side current transformer is obtained.

Further, the method for adaptively adjusting the balance coefficient further includes:

acquiring a preset balance coefficient updating threshold;

judging whether the gear change value is larger than the preset balance coefficient updating threshold value or not;

if not, the original balance coefficient is not adjusted;

the adjusting the original balance coefficient according to the gear change value to obtain the adjusted balance coefficient of the converter transformer comprises: and if the gear change value is larger than the preset balance coefficient updating threshold value, adjusting the original balance coefficient according to the gear change value to obtain the adjusted balance coefficient of the converter transformer.

Further, the circuit data further comprises a high-voltage side current transformer transformation ratio and a low-voltage side current transformer transformation ratio;

the differential current is obtained according to the following formula:

I_D＝I₁₂+K_new*I₂₂Wherein, in the step (A),

wherein, I_DSaid differential current, I₁₂Is a high side secondary current, I₂₂Is a low side secondary current, N_LIs the transformation ratio of the low-voltage side current transformer, N_HFor the transformation ratio of the high-side current transformer, K_NewAnd K is the adjusted balance coefficient, K is the original balance coefficient, and n is the gear change value.

Preferably, the obtaining the gear change value of the converter transformer includes: and obtaining the gear change value of the converter transformer by connecting the tap gear acquisition device of the converter transformer to a corresponding digital acquisition node in the protection device of the converter transformer.

The embodiment of the present invention further provides an electronic device, which is characterized by comprising a memory, a processor, and a computer program stored in the memory and capable of running on the processor, wherein the processor implements the method for adaptively adjusting the balance coefficient when executing the computer program.

Compared with the prior art, the method has the following advantages:

the invention provides a method for adaptively adjusting a balance coefficient, which comprises the following steps: obtaining circuit data of the converter transformer; obtaining an original balance coefficient of the converter transformer according to the circuit data; obtaining a gear change value of the converter transformer; adjusting the original balance coefficient according to the gear change value to obtain an adjusted balance coefficient of the converter transformer; and obtaining the differential current of the converter transformer according to the adjusted balance coefficient of the converter transformer.

The method for adaptively adjusting the balance coefficient aims at the defect that the balance coefficient of the converter transformer cannot be adaptively adjusted according to the gear change value of the converter transformer, and adaptively adjusts the balance coefficient according to the gear change of the converter transformer, so that the increase of differential current of the converter transformer caused by the gear change can be effectively avoided, meanwhile, the sensitivity of differential protection is not sacrificed, and the safe and stable operation of the converter transformer is more reliably ensured.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments of the present invention will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without inventive labor.

FIG. 1 is a schematic flow chart of a method for adaptively adjusting a balance coefficient according to an embodiment of the present invention;

fig. 2 is a schematic diagram of current and voltage collection wiring of a converter transformer according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 1, an embodiment of the present invention provides a method for adaptively adjusting a balance coefficient, where the method for adaptively adjusting a balance coefficient includes:

step S01: obtaining circuit data of the converter transformer;

step S02: obtaining an original balance coefficient of the converter transformer according to the circuit data;

step S03: obtaining a gear change value of the converter transformer;

step S04: adjusting the original balance coefficient according to the gear change value to obtain an adjusted balance coefficient of the converter transformer;

in particular, according to the following formula, according toAdjusting the original balance coefficient by the gear change value to obtain the adjusted balance coefficient K of the converter transformer_New：

Wherein, K_NewAnd K is the adjusted balance coefficient, K is the original balance coefficient, and n is the gear change value.

Step S05: and obtaining the differential current of the converter transformer according to the adjusted balance coefficient of the converter transformer.

By adopting the scheme, the value of the balance coefficient is adjusted in a self-adaptive manner according to the gear change value of the tap joint of the converter transformer, so that the increase of the differential current of the converter transformer caused by the gear change can be effectively avoided, the misoperation of the protection device of the converter transformer is further caused, meanwhile, the sensitivity of the differential protection is not sacrificed, and the safe and stable operation of the converter transformer is more reliably ensured.

In a preferred embodiment of the present invention, when circuit data is collected, an ammeter is connected in series in the circuit, and the access method of the ammeter refers to fig. 2, according to step S01: obtaining circuit data of the converter transformer; collecting primary current of a high-voltage side and primary current of a low-voltage side, and simultaneously obtaining the transformation ratio of a high-voltage side current transformer and the transformation ratio of a low-voltage side current transformer;

according to step S02: obtaining an original balance coefficient of the converter transformer according to the circuit data;

specifically, the original equilibrium coefficient K is obtained according to the following formula:

wherein, I₁Is the primary current of the high-voltage side, I₂For the low side primary current, N_LIs the transformation ratio of the low-voltage side current transformer, N_HAnd the transformation ratio of the high-voltage side current transformer is obtained.

In the specific implementation process, the transformation ratio N of the high-voltage side current transformer_HAnd the transformation ratio N of the low-voltage side current transformer_LThe fixed value is a fixed value, and can be obtained according to the actual model of the converter transformer and the setting condition of the converter transformer, and can be set according to the actual model of the converter transformer or imported according to the internal setting of the converter transformer in a computer program for implementing the method of the present invention.

According to step S03: obtaining a gear change value of the converter transformer;

according to step S04: adjusting the original balance coefficient according to the gear change value to obtain an adjusted balance coefficient of the converter transformer;

wherein, K_NewAnd K is the adjusted balance coefficient, K is the original balance coefficient, and n is the gear change value. Obtaining a differential current according to the circuit data, the gear change value and the original balance coefficient according to the following formula:

I_D＝I₁₂+K_new*I₂₂Wherein, in the step (A),

wherein, I_DIs the differential current, I₁₂Is a high side secondary current, I₂₂Is a low side secondary current, N_LIs the transformation ratio of the low-voltage side current transformer, N_HFor the transformation ratio of the high-side current transformer, K_NewAnd K is the adjusted balance coefficient, K is the original balance coefficient, and n is the gear change value.

By adopting the scheme, the value of the original balance coefficient K is obtained according to the formula according to the primary current at the high-voltage side, the primary current at the low-voltage side, the transformation ratio of the current transformer at the high-voltage side, the transformation ratio of the current transformer at the low-voltage side and the gear change value of the converter transformer.

Optionally, in the above scheme, in order to facilitate calculation of the original balance coefficient, a voltmeter may also be connected in parallel in the circuit when circuit data is acquired, an access method of the voltmeter refers to fig. 2, and the circuit data includes a high-voltage side line voltage, a low-voltage side line voltage, a high-voltage side current transformer transformation ratio and a low-voltage side current transformer transformation ratio;

obtaining the original balance coefficient according to the following formula:

wherein, U₁For the original high side line voltage, U₂For the original low side line voltage, N_LIs the transformation ratio of the low-voltage side current transformer, N_HAnd the transformation ratio of the high-voltage side current transformer is obtained.

By adopting the scheme, the value of the original balance coefficient K is obtained according to the formula according to the original high-voltage side line voltage, the original low-voltage side voltage, the low-voltage side current transformer transformation ratio and the high-voltage side current transformer transformation ratio.

In a further preferred embodiment of the invention, the acquisition circuit data comprise voltage data on the high-voltage side and voltage data on the low-voltage side and the three-phase total capacity of the alternating current. According to step S01: obtaining circuit data of the converter transformer; the circuit data includes an original high-voltage side line voltage and a three-phase total capacity; the original high-side primary current is obtained according to the following formula:

wherein, is the primary current of the high-voltage side, S is the total capacity of the three phases, and is the original high-voltage side line voltage.

The circuit data further includes an original low-side line voltage and a total three-phase capacity; the low-voltage side primary current is obtained according to the following formula:

wherein, is the primary current of the low-voltage side, S is the total capacity of the three phases, and is the original low-voltage side line voltage.

The circuit data specifically further comprises a transformation ratio N of the high-voltage side current transformer_HAnd the transformation ratio N of the low-voltage side current transformer_L(ii) a In the specific implementation process, the transformation ratio N of the high-voltage side current transformer_HAnd the transformation ratio N of the low-voltage side current transformer_LThe fixed value is a fixed value, and can be obtained according to the actual model of the converter transformer and the setting condition of the converter transformer, and can be set according to the actual model of the converter transformer or imported according to the internal setting of the converter transformer in a computer program for implementing the method of the present invention.

According to step S02: obtaining an original balance coefficient of the converter transformer according to the circuit data; specifically, the original balance coefficient is obtained according to the following formula:

wherein N is_LIs the transformation ratio of the low-voltage side current transformer, N_HAnd the transformation ratio of the high-voltage side current transformer is obtained.

According to step S03: obtaining a gear change value of the converter transformer;

according to step S04: adjusting the original balance coefficient according to the gear change value to obtain an adjusted balance coefficient of the converter transformer;

wherein, K_NewAnd K is the adjusted balance coefficient, K is the original balance coefficient, and n is the gear change value.

According to step S05: and obtaining the differential current of the converter transformer according to the adjusted balance coefficient of the converter transformer.

Specifically, the differential current is obtained according to the following formula:

I_D＝I₁₂+K_new*I₂₂Wherein, in the step (A),

wherein, I_DIs the differential current, I₁₂Is a high side secondary current, I₂₂Is a low side secondary current, N_LIs the transformation ratio of the low-voltage side current transformer, N_HFor the transformation ratio of the high-side current transformer, K_NewAnd K is the adjusted balance coefficient, K is the original balance coefficient, and n is the gear change value.

By adopting the scheme, the value of the original balance coefficient K is obtained according to the original high-voltage side line voltage, the original low-voltage side line voltage and the three-phase total capacity and the corresponding current data is calculated according to the voltage data and the formula, for example, only the voltmeter is available under the condition that personnel and equipment of the transformer substation are limited, and in order not to influence the normal work of the converter transformer, the voltmeter is connected in parallel in the circuit of the converter transformer, the circuit does not need to be transformed, the operation is convenient, the circuit is not influenced, the acquisition points for acquiring the circuit data are fewer, the human errors and the random errors can be reduced to the maximum extent, and the calculation accuracy is ensured.

In a specific implementation process, in order to avoid a large calculation burden caused by frequent adjustment of the balance coefficient, the method for adaptively adjusting the balance coefficient further includes:

acquiring a preset balance coefficient updating threshold;

judging whether the gear change value is larger than the preset balance coefficient updating threshold value or not;

if not, the original balance coefficient is not adjusted;

the adjusting the original balance coefficient according to the gear change value to obtain the adjusted balance coefficient of the converter transformer comprises: and if the gear change value is larger than the preset balance coefficient updating threshold value, adjusting the original balance coefficient according to the gear change value to obtain the adjusted balance coefficient of the converter transformer.

By adopting the scheme, the updating threshold value of the balance coefficient is set, so that the refreshing frequency of the K value can be reduced, and the problem of large calculation burden caused by frequent adjustment of the balance coefficient is avoided.

In a specific implementation process, assuming that the balance coefficient update threshold is a, a is a natural number, and if a is 0, adjusting an original balance coefficient K to K whenever a converter transformer gear changes_New(ii) a If A is 1, when the converter transformer gear change value is larger than or equal to 2, the K value is automatically recalculated. In a preferred embodiment of the present invention, a is set to 1, so that frequent adjustment of the K value can be avoided.

In the implementation, for example, the transformation ratio N of the high-voltage side current transformer is known_HAnd the transformation ratio N of the low-voltage side current transformer_LIs a fixed value, see FIG. 2, I₁Collecting primary current I of high-voltage side₂Collecting primary current of a low-voltage side, and when the gear of a tap changer of the converter is adjusted, if A is 0, assuming that the gear is reduced by one gear (equivalent to the step length of 1.25%), K is_New0.9877K, assuming that the gear is down by n,

when the original balance coefficient K is adjusted to be K_NewWhen, according to K_NewCalculating new differential current, and obtaining the differential current according to the following formula:

I_D＝I₁₂+K_new*I₂₂Wherein, in the step (A),

wherein, I_DIs the differential current, I₁Is the primary current of the high-voltage side, I₂Is the primary current of the low voltage side, I₁₂Is a high side secondary current, I₂₂Is a low side secondary current, N_LIs the transformation ratio of the low-voltage side current transformer, N_HFor the transformation ratio of the high-side current transformer, K_NewAnd K is the adjusted balance coefficient and the original balance coefficient.

The calculation method for adaptively adjusting the balance coefficient can enable the K value to be automatically adjusted along with the change of tap joint gears of the converter transformer, thereby ensuring that I_D＝I₁₂+K*I₂₂And the current is approximately equal to 0, and the purpose of more accurately obtaining the differential current of the converter transformer can be achieved by adopting the scheme. The sensitivity of the converter transformer differential protection is ensured, and unbalanced current generated when the gear of the tap is changed can be avoided.

In the specific implementation process, the gear change value acquisition mode of the converter transformer is as follows: and connecting the converter transformer tap position acquisition device into a corresponding digital acquisition node in a protection device of the converter transformer. Specifically, the converter transformer gear value collection mode can utilize 8421BCD codes to collect the gear value, eight digits are used in total, the first four digits are ten digits of the gear, and the second four digits are ones of the gear. By adopting the scheme, the gear value of the converter transformer can be accurately acquired, and the change of the gear can be quickly captured.

Specifically, the following illustrates the practical application, for example, when the tap gear of the converter transformer is at 26 gears, the 8421BCD code is 00100100110, 00100100100110 is used to indicate that the gear change value is 26, and the tap gear collecting device of the converter transformer is electrically connected to the differential protection device of the converter transformer for adjusting the original balance coefficient K to K according to the gear change value and the circuit data of the converter transformer_NewAccording to K_NewCalculating new differential current, and the differential protection device of the converter transformer can be based on the new differenceAnd judging whether to start the protection of the converter transformer by the aid of the current.

The embodiment of the invention also provides electronic equipment which comprises a memory, a processor and a computer program which is stored on the memory and can run on the processor, wherein the processor realizes the method for adaptively adjusting the balance coefficient when executing the computer program. As an example, the electronic device may be a converter transformer.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.