阅读说明：本技术 一种励磁调节器低励限制的实现方法 (Method for realizing low excitation limit of excitation regulator ) 是由 桂刚 张锦春 王帅 夏云龙 仰帅 龚梦杰 于 2019-11-13 设计创作，主要内容包括：本发明公开了一种励磁调节器低励限制的实现方法,该方法包括：设定同步发电机功角限制值为δref,在同步发电机运行过程中,低励限值计算发电机功角δ的余弦值cosδ,当发电机功角δ大于发电机功角限制值δref时,计算其余弦偏差err＝cos(δref)-cosδ,低励限值器输出低励限制信号。本发明相对于传统的低励限制器,仅需输入一个定值,计算过程简单、计算量小,采取功角的余弦值作为控制对象,功角越大输出的余弦偏差值越小,调节更加稳定、更加可靠。(The invention discloses a method for realizing low excitation limit of an excitation regulator, which comprises the following steps: setting a power angle limiting value of the synchronous generator as delta ref, calculating a cosine value cos delta of the power angle delta of the generator by using a low excitation limiting value in the operation process of the synchronous generator, calculating the residual chord deviation err as cos (delta ref) -cos delta when the power angle delta of the generator is greater than the power angle limiting value delta ref, and outputting a low excitation limiting signal by using the low excitation limiting value. Compared with the traditional low excitation limiter, the low excitation limiter only needs to input a fixed value, has simple calculation process and small calculation amount, takes the cosine value of the power angle as a control object, and has more stable and more reliable adjustment because the larger the power angle is, the smaller the output cosine deviation value is.)

1. A method for achieving a low excitation limit of an excitation regulator, the method comprising the steps of:

the method comprises the following steps: setting a power angle limiting value of the synchronous generator to be delta ref;

step two: in the operation process of the synchronous generator, calculating a cosine value cos delta of a power angle delta of the generator by using a low excitation limit value;

step three: when the power angle delta of the generator is larger than the power angle limiting value delta ref of the generator, calculating the deviation err of the rest strings_UELThe low excitation limiting device outputs a low excitation limiting signal to increase the excitation voltage of the generator.

2. The method for realizing the low excitation limit of the excitation regulator according to claim 1, wherein the power angle limit value δ ref is a low excitation limit setting value, specifically a preset value, and a value range of δ ref is 0 to 90 degrees.

3. The method for realizing the low excitation limit of the excitation regulator according to claim 1, wherein the low excitation limit value calculation generator power angle δ is a value calculated by the low excitation limit value calculation device according to the active power, the reactive power and the voltage of the generator.

4. The method as claimed in claim 1, wherein the low excitation limit signal of the low excitation limit output is multiplied by a factor K, the value K is a predetermined value, and the value of the value K is in the range of 0.01 to 0.05.

5. The method as claimed in claim 1, wherein the power angle of the synchronous generator is controlled in real time to control err_UELThe cos (δ ref) -cos δ is a control deviation, and the power angle of the synchronous generator is limited within an allowable range.

6. The method for realizing the low excitation limit of the field regulator according to claim 1, wherein the power angle of the synchronous generator is limited within an allowable range, specifically, the power angle δ of the synchronous generator is smaller than a power angle limit value δ ref of the synchronous generator.

7. A method as claimed in any one of claims 1 or 5, wherein err is arranged to achieve a low excitation limit for the field regulator_UELOutputting a delay with the time T, presetting the delay time T through the outside, and setting the value range of T to be 10ms-1 s.

8. A method as claimed in any one of claims 1 or 5, wherein err is arranged to achieve a low excitation limit for the field regulator_UELThe output is subjected to amplitude limiting, the lower limit is 0, the upper limit is preset by a user, and the value range of the upper limit is 0-100%.

Technical Field

The invention belongs to the technical field related to operation and safety of an electric power system, and particularly relates to a method for realizing low excitation limit of an excitation regulator.

Background

The excitation regulator of the self-shunt static rectification excitation system is developed from a semiconductor discrete element to an integrated solid component and from an analog mode to a digital mode. Excitation regulators can be classified into three major categories, namely semiconductor analog excitation regulators, digital excitation regulators with programmable controllers in microcomputers, and analog excitation regulators with programmable controllers in hybrid microcomputers.

However, in the operation process of the existing synchronous generator, the low excitation limit setting process of the excitation regulator is complex and troublesome in practical application; in order to solve this technical drawback, a solution is now provided.

Disclosure of Invention

The invention aims to provide a method for realizing low excitation limit of an excitation regulator.

The purpose of the invention can be realized by the following technical scheme:

a method of achieving a low excitation limit for an excitation regulator, the method comprising the steps of:

the method comprises the following steps: setting a power angle limiting value of the synchronous generator to be delta ref;

step two: in the operation process of the synchronous generator, calculating a cosine value cos delta of a power angle delta of the generator by using a low excitation limit value;

step three: when the power angle delta of the generator is larger than the power angle limiting value delta ref of the generator, calculating the deviation err of the rest strings_UELThe low excitation limiting device outputs a low excitation limiting signal to increase the excitation voltage of the generator.

Further, the power angle limiting value δ ref is a low excitation limiting value setting value, specifically a preset value, and the value range of δ ref is 0-90 degrees.

Further, the power angle δ of the generator calculated by the low excitation limit value is a value calculated by the low excitation limit value device according to the active power, the reactive power and the voltage of the generator.

Furthermore, the low excitation limit signal output by the low excitation limit should be multiplied by a coefficient K, the K value is a preset value, and the value range of the K value is 0.01-0.05.

Further, the power angle of the synchronous generator is controlled in real time to err_UELThe cos (δ ref) -cos δ is a control deviation, and the power angle of the synchronous generator is limited within an allowable range.

Further, the power angle of the synchronous generator is limited within an allowable range, specifically, the power angle δ of the synchronous generator is smaller than the power angle limit value δ ref of the synchronous generator.

Further, err_UELOutputting a delay with the time T, presetting the delay time T through the outside, and setting the value range of T to be 10ms-1 s.

Further, err_UELThe output is subjected to amplitude limiting, the lower limit is 0, the upper limit is preset by a user, and the value range of the upper limit is 0-100%.

The invention has the beneficial effects that:

compared with the traditional low excitation limiter, the low excitation limiter only needs to input a fixed value, has simple calculation process and small calculation amount, takes the cosine value of the power angle as a control object, and has more stable and more reliable adjustment because the larger the power angle is, the smaller the output cosine deviation value is. The invention is simple, effective and easy to use.

Drawings

In order to facilitate understanding for those skilled in the art, the present invention will be further described with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of a method of implementing the low excitation limit of the present invention;

FIG. 2 is a low excitation limit post-commissioning simulated waveform generator designed using the method of the present invention at a voltage-2% step;

FIG. 3 is a simulated waveform without the low excitation limit at a voltage-2% step.

Detailed Description

1-3, a method for implementing a low excitation limit of an excitation regulator is provided;