CN201167238Y

CN201167238Y - A power system stabilizer

Info

Publication number: CN201167238Y
Application number: CNU2007203001073U
Authority: CN
Inventors: 毛承雄; 陆继明; 周友斌; 李小平; 熊鸿滔; 王丹; 娄慧波
Original assignee: HUBEI PROV POWER TEST INST; Huazhong University of Science and Technology
Current assignee: Huazhong University of Science and Technology; Electric Power Research Institute of State Grid Hubei Electric Power Co Ltd; State Grid Corp of China SGCC
Priority date: 2007-12-21
Filing date: 2007-12-21
Publication date: 2008-12-17
Anticipated expiration: 2017-12-21

Abstract

The utility model discloses a power system stabilizer, which comprises a filter, a reset device, a phase compensator and a voltage limiter connected in sequence, the filter is used for filtering the input signal, and the reset device is used for eliminating the DC component of the filtered input signal , the phase compensator is used to use the phase compensation transfer function to perform phase compensation on the input signal after the DC component is eliminated to obtain the phase compensation output signal, and the voltage limiter is used to limit the voltage of the phase compensation output signal and output the voltage limit result. The phase compensator in the utility model adopts a phase compensation transfer function whose numerator and denominator are both polynomials. Its parameters have a large degree of freedom in selection and can better approach the required target compensation curve, so that the lag phase of the generator can be well controlled in the entire low-frequency oscillation range. compensation.

Description

A power system stabilizer

技术领域 technical field

本实用新型属于电气工程技术领域，具体涉及一种电力系统稳定器(Power System Stabilizer，PSS)。The utility model belongs to the technical field of electrical engineering, in particular to a power system stabilizer (Power System Stabilizer, PSS).

背景技术 Background technique

目前，公知的PSS结构是由相位补偿环节、附加励磁放大倍数、复位环节、传感器及输入信号部分组成。引入一个或者两个信号，通过励磁系统去增加电力系统中发电机的阻尼转矩。常用PSS一般根据无阻尼的自然机械模式频率jω_n或者由系统特征值分析得到的本机振荡模式的复数频率σ+jω进行设计，因此PSS对设计频率及其附近频率的功率振荡有着很好的抑制效果。At present, the known PSS structure is composed of a phase compensation link, an additional excitation magnification, a reset link, a sensor and an input signal. Introduce one or two signals to increase the damping torque of the generator in the power system through the excitation system. The commonly used PSS is generally designed according to the undamped natural mechanical mode frequency jω _n or the complex frequency σ+jω of the local oscillation mode obtained from the system eigenvalue analysis, so the PSS has a good effect on the power oscillation of the design frequency and its nearby frequencies. Inhibitory effect.

随着区域电网的互联，电力系统中发电机参与的强相关振荡模式可能会有两个或两个以上，为了电力系统的安全稳定运行，要求PSS抑制低频振荡的范围为0.1Hz～3Hz。常规PSS的相位补偿部分由两级或三级超前滞后环节组成，很难满足要求，原因是：一方面三级超前滞后环节产生超前相位的极限为150°～160°，而电力系统中很多发电机滞后相位往往超过200°，无法进行补偿；另一方面两到三级的超前滞后环节只有4～6个参数，很难在整个低频振荡范围内对发电机滞后相位进行补偿。With the interconnection of regional power grids, there may be two or more strongly correlated oscillation modes in which generators participate in the power system. For the safe and stable operation of the power system, PSS is required to suppress low-frequency oscillations in the range of 0.1 Hz to 3 Hz. The phase compensation part of the conventional PSS is composed of two or three stages of lead-lag links, which is difficult to meet the requirements. The reason is that: on the one hand, the limit of the lead phase generated by the three-stage lead-lag links is 150°~160°, and many power generation in the power system The generator lag phase often exceeds 200°, which cannot be compensated; on the other hand, the two- to three-stage lead-lag link has only 4 to 6 parameters, and it is difficult to compensate the generator lag phase in the entire low-frequency oscillation range.

发明内容 Contents of the invention

本实用新型的目的是提出一种电力系统稳定器，能够在0.1Hz～3Hz低频振荡范围内对发电机滞后相位进行良好的补偿。The purpose of the utility model is to propose a power system stabilizer, which can well compensate the lagging phase of the generator in the low-frequency oscillation range of 0.1 Hz to 3 Hz.

本实用新型提供的电力系统稳定器，其特征在于，包括依次连接的滤波器、复位器、相位补偿器和限伏器，滤波器用于对输入信号滤波，复位器用于消除滤波后的输入信号的直流分量，相位补偿器用于采用相位补偿传递函数对消除直流分量后的输入信号进行相位补偿，得到相位补偿输出信号，限伏器用于对相位补偿输出信号限伏，输出限伏结果。The power system stabilizer provided by the utility model is characterized in that it includes a filter, a reset device, a phase compensator and a voltage limiter connected in sequence, the filter is used to filter the input signal, and the reset device is used to eliminate the distortion of the input signal after filtering. The DC component, the phase compensator is used to perform phase compensation on the input signal after the DC component is eliminated by using the phase compensation transfer function to obtain the phase compensation output signal, and the voltage limiter is used to limit the voltage of the phase compensation output signal and output the voltage limit result.

本实用新型中的相位补偿器采用分子分母均为多项式的相位补偿传递函数，其参数选择自由度大，能够较好逼近所需目标补偿曲线，从而在整个低频振荡范围对发电机滞后相位进行良好的补偿。The phase compensator in the utility model adopts a phase compensation transfer function whose numerator and denominator are both polynomials. Its parameters have a large degree of freedom in selection and can better approach the required target compensation curve, so that the lag phase of the generator can be well controlled in the entire low-frequency oscillation range. compensation.

附图说明 Description of drawings

图1为本实用新型结构示意图；Fig. 1 is a structural representation of the utility model;

图2为实施例拟合结果示意图。Fig. 2 is a schematic diagram of the fitting results of the embodiment.

具体实施方式 Detailed ways

下面结和附图和实例对本实用新型作进一步详细的说明。Below knot and accompanying drawing and example the utility model is described in further detail.

如图1所示，本实用新型包括：依次相连接的滤波器1、复位器2、相位补偿器3和限伏器4。As shown in FIG. 1 , the utility model includes: a filter 1 , a reset device 2 , a phase compensator 3 and a voltage limiter 4 connected sequentially.

滤波器1对输入信号进行滤波，以消除输入信号中的干扰，并滤除输入信号中的低频振荡频率以外信号。一般作为PSS输入信号有：发电机转子转速ω、发电机功率Pe和加速功率Pa。滤波器分为两种，当输入信号为转速ω或电功率Pe时，滤波器传递函数为

其中A₁，A₁为滤波器参数，A₁，A₁∈(0，0.5)。当输入信号为加速功率Pa时，滤波器的形式为

其中T₈，T₉，M，N为滤波器参数，T₈，T₉∈(0.1，0.5)，M，N∈(1，5)，拉普拉斯变换因子s为复变量。The filter 1 filters the input signal to eliminate the interference in the input signal, and filters out the signals other than the low-frequency oscillation frequency in the input signal. Generally used as PSS input signals are: generator rotor speed ω, generator power Pe and acceleration power Pa. There are two types of filters. When the input signal is the speed ω or electric power Pe, the filter transfer function is

Wherein A ₁ , A ₁ are filter parameters, A ₁ , A ₁ ∈(0, 0.5). When the input signal is the acceleration power Pa, the form of the filter is

Where T ₈ , T ₉ , M, N are filter parameters, T ₈ , T ₉ ∈ (0.1, 0.5), M, N ∈ (1, 5), and the Laplace transform factor s is a complex variable.

复位器2用于消除滤波后的输入信号中的直流分流，复位器的传递函数为

T_ω为复位环节时间常数，T_ω取值范围为(4，15)。Resetter 2 is used to eliminate the DC shunt in the filtered input signal, and the transfer function of the resetter is

T _ω is the time constant of the reset link, and the value range of T _ω is (4, 15).

相位补偿器3对消除直流分量后的输入信号进行相位补偿得到相位补偿环节输出信号。The phase compensator 3 performs phase compensation on the input signal after the DC component is eliminated to obtain the output signal of the phase compensation link.

限伏器4对相位补偿环节输出信号进行限伏，限伏范围由发电机、发电机地理位置等实际情况确定，再将限伏后的相位补偿环节输出信号向外部发电机自动调压装置输出，用作增强电力系统正阻尼的附加励磁控制信号。限伏器为一个判断机构，当输入信号在(u_smin，u_smax)之间，输出信号为输入信号；当输入信号小于u_smin，输出信号为u_smin；当输出信号大于u_smax，输出信号为u_smax，其中u_smin，u_smax∈(-0.5，0.5)，u_smin＜u_smax。The voltage limiter 4 limits the voltage of the output signal of the phase compensation link, and the range of the voltage limit is determined by the actual conditions such as the generator and the geographical location of the generator, and then outputs the output signal of the phase compensation link after the voltage limit to the external generator automatic voltage regulation device , used as an additional excitation control signal to enhance the positive damping of the power system. The voltage limiter is a judging mechanism. When the input signal is between (u _smin , u _smax ), the output signal is the input signal; when the input signal is less than u _smin , the output signal is u _smin ; when the output signal is greater than u _smax , the output signal is is u _smax , where u _smin , u _smax ∈ (-0.5, 0.5), u _smin <u _smax .

相位补偿器采取的相位补偿传递函数按照以下步骤确定：The phase compensation transfer function adopted by the phase compensator is determined according to the following steps:

1)通过频谱测量仪从现场测量或者仿真计算获得发电机的相位特性

1) Obtain the phase characteristics of the generator from on-site measurement or simulation calculation through the spectrum measuring instrument

2)根据预定补偿要求计算PSS补偿相位特性

2) Calculate the PSS compensation phase characteristics according to the predetermined compensation requirements

PSS输入信号不同时要求补偿的相位特性

也不同。引入转子转速ω作为输入信号时，相位特性

引入发电机功率Pe或加速功率Pa作为输入信号时相位特性

为预定补偿要求，

Compensation phase characteristics are required when PSS input signals are different

Also different. When the rotor speed ω is introduced as the input signal, the phase characteristic

Phase characteristics when generator power Pe or acceleration power Pa is introduced as input signal

For scheduled compensation claims,

由于滤波环节和复位环节在超低频段对相位补偿有较大的影响，进行拟合的时候需要考虑这些环节的相位特性，对相位特性

作相应的修正：引入转子转速ω作为输入信号时，相位特性

引入-Pe或加速功率Pa作为输入信号时相位特性

为预定补偿要求，

为滤波及复位环节修正因子，

Since the filtering link and the reset link have a great influence on the phase compensation in the ultra-low frequency band, it is necessary to consider the phase characteristics of these links when performing fitting.

Make corresponding corrections: when the rotor speed ω is introduced as the input signal, the phase characteristic

Phase characteristics when -Pe or acceleration power Pa is introduced as input signal

For scheduled compensation claims,

is the correction factor of the filtering and reset link,

3)将补偿相位特性

作为目标曲线，以式(1)为原函数进行曲线拟合，得到一条最逼近于目标曲线的相位补偿曲线f(x)，即相位补偿曲线与目标曲线之差在某种度量意义下为最小。常用的度量标准有

为了加强某些频段的拟合效果在度量标准中加入加权函数，形式如：

其中，a、b为曲线拟合范围，a，b∈(0，50)，a＜b，ω(x)为加权函数。3) will compensate the phase characteristic

As the target curve, use equation (1) as the original function to perform curve fitting, and obtain a phase compensation curve f(x) that is closest to the target curve, that is, the difference between the phase compensation curve and the target curve is the smallest in a certain sense of measurement . Commonly used metrics are

In order to strengthen the fitting effect of certain frequency bands, a weighting function is added to the metric, in the form of:

Wherein, a and b are curve fitting ranges, a, b∈(0, 50), a<b, and ω(x) is a weighting function.

$\frac{{b b}_{00} {s the s}^{n no} + + {b b}_{11} {s the s}^{n no - - 11} + + \cdot &Center Dot; \cdot &Center Dot; \cdot &Center Dot; + + {b b}_{n no}}{{s the s}^{n no} + + {a a}_{11} {s the s}^{n no - - 11} + + \cdot &Center Dot; \cdot &Center Dot; \cdot &Center Dot; + + {a a}_{n no}} - - - - - - ((11))$

式(1)的分子是等于或者小于n阶的多项式，分母是n阶多项式，其中多项式系数b₀、b₁、…、b_n，a₁、a₂、…、a_n和自然数n为拟合参数，s为拉普拉斯变换因子，为复变量。以式(1)为原函数，根据发电机相频特性进行拟合，得到PSS的相位补偿曲线即确定了拟合参数n，b₀、b₁、…、b_n，a₁、a₂、…、a_n，该参数值确定了相位补偿传递函数。该传递函数由于分子，分母均采用多项式的形式，参数自由度大，能够使拟合得到的相位补偿曲线更相近于目标曲线，从而有利于提高相位补偿效果。The numerator of formula (1) is a polynomial equal to or less than nth order, and the denominator is an nth order polynomial, in which polynomial coefficients b ₀ , b ₁ , ..., b _n , a ₁ , a ₂ , ..., a _n and natural number n are quasi Combined parameters, s is the Laplace transform factor, and is a complex variable. Using formula (1) as the original function, fitting according to the phase-frequency characteristics of the generator, and obtaining the phase compensation curve of the PSS, the fitting parameters n, b ₀ , b ₁ ,..., b _n , a ₁ , a ₂ , ..., a _n , the parameter value determines the phase compensation transfer function. Since both the numerator and the denominator of the transfer function are in the form of polynomials, the degree of freedom of parameters is large, and the fitted phase compensation curve can be closer to the target curve, which is conducive to improving the phase compensation effect.

实际应用中，在采用式(1)拟合时，可能出现正极点情形，为避免该情形，进一步提出如式(2)或式(3)进行拟合，In practical applications, when fitting with formula (1), there may be a positive pole situation. In order to avoid this situation, it is further proposed to perform fitting as formula (2) or formula (3),

$\frac{{b b}_{00} {s the s}^{n no} + + {b b}_{11} {s the s}^{n no - - 11} + + \cdot &Center Dot; \cdot \cdot \cdot \cdot + + {b b}_{n no}}{((11 + + s the s {T T}_{11})) ((11 + + s the s {T T}_{22})) \cdot &Center Dot; \cdot &Center Dot; \cdot &Center Dot; ((11 + + s the s {T T}_{n no}))} - - - - - - ((22))$

式(2)中：n为自然数，T_i＞0，i＝1，…，n，n、b₀、b₁、…、b_n、T₁、T₂、…、T_n为拟合参数。In formula (2): n is a natural number, T _i > 0, i = 1, ..., n, n, b ₀ , b ₁ , ..., b _n , T ₁ , T ₂ , ..., T _n are fitting parameters .

$\frac{{b b}_{00} {s the s}^{n no} + + {b b}_{11} {s the s}^{n no - - 11} + + \cdot &Center Dot; \cdot &Center Dot; \cdot &Center Dot; + + {b b}_{n no}}{((11 + + {a a}_{1111} s the s + + {a a}_{1212} {s the s}^{22})) \cdot &Center Dot; \cdot &Center Dot; \cdot &Center Dot; ((11 + + {a a}_{j j 11} s the s + + {a a}_{j j 22} {s the s}^{22})) ((11 + + s the s {T T}_{11})) \cdot &Center Dot; \cdot &Center Dot; \cdot &Center Dot; ((11 + + s the s {T T}_{k k}))} - - - - - - ((33))$

式(3)中：2j+k＝n，n、j和k为自然数，T_l＞0，l＝1，…，k，n、b₀、b₁、…、b_n、a₁₁、…、a_j1、a₁₂、…、a_j2为拟合参数，1+a_u1s+a_u2s²，u＝1，…，j，为具有负实部共轭复根的2阶多项式。In formula (3): 2j+k=n, n, j and k are natural numbers, T _l >0, l=1, ..., k, n, b ₀ , b ₁ , ..., b _n , a ₁₁ , ... , a _j1 , a ₁₂ , ..., a _j2 are fitting parameters, 1+a _u1 s+a _u2 s ² , u=1, ..., j, are second-order polynomials with negative real part conjugate complex roots.

式(2)和式(3)的区别是：式(2)的分母为n个1阶因式相乘，其极点全部为负实根，而式(3)的分母为1阶和2阶因式混合相乘，其极点为负实根和共轭复根(负实部)。式(3)的自由度比式(2)要大，但式(2)更符合实际习惯。如果式(1)的极点全部为稳定的，则式(1)总可以转换成式(2)或式(3)的形式。式(2)、式(3)以及式(1)都很容易离散化后在计算机上实时实现。The difference between formula (2) and formula (3) is: the denominator of formula (2) is the multiplication of n 1st-order factors, and its poles are all negative real roots, while the denominator of formula (3) is 1st-order and 2nd-order Mixed multiplication of factors whose poles are negative real roots and conjugate complex roots (negative real parts). Formula (3) has more degrees of freedom than formula (2), but formula (2) is more in line with practical habits. If the poles of formula (1) are all stable, then formula (1) can always be transformed into the form of formula (2) or formula (3). Formula (2), formula (3) and formula (1) are all easy to discretize and realize in real time on the computer.

本实用新型的核心在于相位补偿器的结构，即相位补偿传递函数的确定，下面结合图3举例说明该过程，图中横坐标为转速，以式(2)为进行拟合。The core of the present utility model is the structure of the phase compensator, i.e. the determination of the phase compensation transfer function, the process is illustrated below in conjunction with Fig. 3, the abscissa in the figure is the rotating speed, and is fitted with formula (2).

(1)获取实际机组的滞后相位，如图3中曲线d；(1) Obtain the lag phase of the actual unit, as shown in curve d in Figure 3;

(2)对曲线4进行处理后得到补偿相位特性，如图3中曲线a所示；(2) After the curve 4 is processed, the compensation phase characteristic is obtained, as shown in the curve a in Fig. 3;

(3)根据补偿相位特性，采用度量标准

以本实用新型式(2)进行拟合得到PSS相位补偿曲线即相位补偿环节参数值，如图3中曲线b所示；拟合得到相位补偿环节传递函数如式(4)所示(3) According to the compensation phase characteristics, the measurement standard is adopted

Fitting with the utility model (2) obtains the PSS phase compensation curve, that is, the phase compensation link parameter value, as shown in curve b in Figure 3; the fitting obtains the phase compensation link transfer function as shown in formula (4)

$\frac{2.99 2.99 * * 1010^{- - 55} {s the s}^{44} + + 1.176 1.176 * * 1010^{- - 33} {s the s}^{33} + + 1.395 1.395 * * 1010^{- - 22} {s the s}^{22} + + 0.2829 0.2829 s the s + + 0.9387 0.9387}{1.6 1.6 * * 1010^{- - 77} {s the s}^{44} + + 3.2 3.2 * * 1010^{- - 55} {s the s}^{33} + + 2.4 2.4 * * 1010^{- - 33} {s the s}^{22} + + 0.08 0.08 s the s + + 11} - - - - - - ((44))$

根据曲线a和曲线b计算补偿误差，如图3中曲线c所示，曲线c位于相位值“0”附近，可见本实用新型在低频振荡范围内能够很好的逼近目标曲线，从而对发电机滞后相位进行良好的补偿。Compensation error is calculated according to curve a and curve b, as shown in curve c in Figure 3, curve c is located near the phase value "0", it can be seen that the utility model can well approach the target curve in the range of low-frequency oscillation, thereby improving the generator Good compensation for lagged phase.

Claims

1, a kind of power system stabilizer, PSS, it is characterized in that, comprise the filter (1), restorer (2), phase compensator (3) and the surge suppressor (4) that connect successively, filter (1) is used for input signal filtering, restorer (2) is used to eliminate the DC component of filtered input signal, input signal after phase compensator (3) is used to adopt the phase compensation transfer function to the elimination DC component carries out phase compensation, obtain the phase compensation output signal, surge suppressor (4) is used for phase compensation output signal limit volt, output limit volt result.