CN112531722B - Reactive voltage control method and system - Google Patents

Abstract

The invention discloses a reactive voltage control method and system, wherein the method includes: obtaining the bus voltage U _H on the high-voltage side; when U _H is greater than the preset upper limit value of the bus voltage on the high-voltage side

, making U _H lower to the preset

below and the lower limit of the bus voltage on the high voltage side

above; when U _H is less than the preset

, making U _H rise to

above and

under; when U _H is in

and

When between, calculate the sum Q _H of the reactive power injected into the local system at the middle point of all lines on the high voltage side, calculate the sum Q _M of the reactive power injected into the local system at the medium voltage side, and calculate the sum Q _HM of Q _H and Q _M , to judge whether the absolute value of Q _HM is greater than the preset partial system reactive power demand balance threshold Q _equi ; when Q _HM is greater than Q _equi , put in a set of capacitive reactive power supplementary equipment or remove a set of inductive reactive power compensation equipment; When the negative number of Q _HM is greater than Q _equi , a group of inductive reactive power supplementary equipment is put into operation.

Description

A reactive voltage control method and system

technical field

The present invention relates to the technical field of reactive voltage analysis and control of power systems, and more specifically, to a reactive voltage control method and system.

Background technique

The problem of reactive power and voltage control has become increasingly prominent in high-proportion new energy power systems. Large-scale wind power, photovoltaic and other new energy bases are generally located in remote places, and often need to be connected and transmitted to the main grid through long-distance AC transmission lines. However, new energy power generation is intermittent and volatile, so the active power flow on the AC line fluctuates greatly and frequently, causing reactive power loss and voltage fluctuations are also very severe and frequent, making it difficult to control the reactive power and voltage of the transmission system, high/low The voltage limit problem is serious, which leads to a high risk of disconnection of new energy units connected along the way, which seriously restricts the safe grid connection and collection and delivery capabilities of new energy, and may endanger the safe and stable operation of the power grid.

Dynamic reactive power compensation devices at home and abroad generally adopt the more traditional control methods based on bus voltage measurement and port reactive power measurement, which cannot effectively reflect the reactive power demand of the power system, so it is difficult to realize the control of system reactive power and voltage. efficient control.

The "nine-area diagram method" of prior art 1 is a traditional method that has been used in the industry for many years. Its basic idea is to use the upper and lower limits of reactive power and voltage to cross-cut nine areas on the reactive voltage-plane and execute Different corresponding control instructions. The "nine-area diagram method" in the prior art mainly has the following two deficiencies: First, the reactive power in the "nine-area diagram method" is directly measured at the high-voltage side of the main transformer of the substation. The power supply substation at the end of the power grid has certain adaptability, but the adaptability is not strong for the transmission network and the substation on the transmission channel where there is a large active power flow through the incoming and outgoing lines, mainly because the reactive power directly measured at this point does not It cannot reflect the real reactive power demand of the local transmission subsystem including the incoming and outgoing lines connected to the station and the main transformer, and cannot eliminate the influence of reactive power through the high and medium voltage sides of the main transformer. Secondly, this method does not prioritize the two variables of voltage and reactive power. It considers reactive power and voltage as variables of a priority level, and they are two equal dimensions on a plane, as shown in Figure 1.

The second existing technology adopts the method of boundary voltage bang-bang control, that is, the reactive power compensation capacity is controlled according to the upper and lower limits of the voltage target. When the actual operating voltage changes within the upper and lower limits, the reactive power compensation equipment does not operate; when the actual operating voltage When the upper and lower limits of the voltage control target are crossed, a set of reactive power compensation equipment is switched on and off accordingly, thereby changing the actual operating voltage at this point in the grid until it can be maintained within the range of the upper and lower limits of the voltage target. Boundary voltage bang-bang control mainly has the following shortcomings: relatively difficult setting of the voltage range boundary, poor adaptability to system operating conditions, poor control accuracy, slow speed, and insufficient switching at the voltage range boundary in some cases Or frequent jitter switching and other issues.

Therefore, a technology is needed to control the reactive voltage.

Contents of the invention

The technical scheme of the present invention provides a reactive voltage control method and system to solve the problem of how to control the reactive voltage.

In order to solve the above problems, the present invention provides a reactive voltage control method, the method comprising:

Obtain the bus voltage U _H on the high voltage side;

时，调整所述高压侧母线电压U_H，使得所述高压侧母线电压U_H降低到预设的高压侧母线电压上限值

之下并且高压侧母线电压下限值

之上；或者When the high voltage side bus voltage U _H is greater than the preset high voltage side bus voltage upper limit

, adjust the high-voltage side bus voltage U _H so that the high-voltage side bus voltage U _H is reduced to the preset upper limit value of the high-voltage side bus voltage

below and the lower limit of the bus voltage on the high voltage side

above; or

时，调整所述高压侧母线电压U_H，使得所述高压侧母线电压U_H升高到预设的高压侧母线电压下限值

之上并且高压侧母线电压上限值

之下；When the high-voltage side bus voltage U _H is less than the preset lower limit value of the high-voltage side bus voltage

, adjust the high-voltage side bus voltage U _H so that the high-voltage side bus voltage U _H rises to the preset lower limit value of the high-voltage side bus voltage

above and the upper limit of the bus voltage on the high voltage side

under;

与高压侧母线电压下限值

之间时，计算高压侧所有线路中点处对局部系统的无功注入之和Q_H，计算中压侧对局部系统的无功注入之和Q_M，计算Q_H与Q_M的和Q_HM，判断Q_HM的绝对值是否大于预设的局部系统无功需求平衡阈值Q_equi；When the high-voltage side bus voltage U _H is at the preset upper limit of the high-voltage side bus voltage

and the lower limit of the bus voltage on the high voltage side

When between, calculate the sum Q _H of the reactive power injected into the local system at the middle point of all lines on the high voltage side, calculate the sum Q _M of the reactive power injected into the local system at the medium voltage side, and calculate the sum Q _HM of Q _H and Q _M , to determine whether the absolute value of Q _HM is greater than the preset partial system reactive power demand balance threshold Q _equi ;

The local system reactive power is controlled based on Q _HM and the preset local system reactive power demand balance threshold Q _equi .

Preferably, the local system reactive power is controlled based on Q _HM and the preset local system reactive power demand balance threshold Q _equi , further comprising:

When Q _HM is greater than the preset partial system reactive power demand balance threshold Q _equi , a set of capacitive reactive power supplementary equipment is put in or a set of inductive reactive power compensation equipment is cut off;

When Q _HM is less than the negative number Q _HM of the preset partial system reactive power demand balance threshold Q _equi , a set of inductive reactive power supplementary equipment is put in or a set of capacitive reactive power compensation equipment is removed;

When the negative number of the preset partial system reactive demand balance threshold Q _equi is equal to Q _HM , the current running state is maintained.

When Q _HM is less than the preset local system reactive power demand balance threshold Q _equi , and when Q _HM is greater than the negative number of the preset local system reactive power demand balance threshold Q _equi , and when all lines on the high-voltage side are at the midpoint The sum Q _H of the reactive power injection to the local system is greater than the reactive power ride-through threshold Q _thr of the local system, or the reactive power injection amount Q _M of the medium-voltage side of the local system is less than the negative number of the reactive power ride-through threshold Q _thr of the local system, and a group of Capacitive reactive power supplementary equipment or removal of a group of inductive reactive power compensation equipment;

Or when Q _HM is less than the preset local system reactive power demand balance threshold Q _equi , and when Q _HM is greater than the negative number of the preset local system reactive power demand balance threshold Q _equi , when the local The sum of reactive power injection Q _H of the system is less than the negative number of the reactive power ride-through threshold Q _thr of the local system, or the reactive power injection amount Q _M of the medium-voltage side of the local system is greater than the reactive power ride-through threshold Q _thr of the local system, and a set of inductive reactive power is put into use. Power supplementary equipment or remove a set of capacitive reactive power compensation equipment.

Preferably, the method for calculating the reactive power injection quantity Q _M of the medium-voltage side of the local system includes:

θi is the angle between the busbar voltage U _M on the medium voltage side and the switch current I _Mi on the outlet line _i on the medium voltage side.

Preferably, the calculation method of the sum Q _H of the reactive power injected into the local system at the midpoints of all lines on the high-voltage side includes:

Q _H ＝Q _dem -Q _L -Q _M

Among them, Q _dem is the reactive power demand of the local system, Q _M is the reactive power injection amount of the medium voltage side of the local system, and Q _L is the reactive power injection amount of the low voltage side of the local system.

Preferably, the calculation method of local system reactive power demand Q _dem includes:

I _Hi Line i high-voltage side outlet switch current;

I _li is the steady-state current of the line i impedance branch, i=1,2,...,n;

X _li is the reactance of line i, i=1,2,...,n;

X _ti is the leakage reactance of transformer i, i=1,2,...,m;

Q _bi is the charging power of half the length line i in the local system, i=1,2,...,n;

Q _ki is the high reactive power of line i, i=1,2,...,n;

The steady-state current I _li of the impedance branch of the line i is calculated by the following formula:

In the formula:

X _ki is the reactance value of the high reactance of line i, i=1,2,...,n;

j is the imaginary unit;

X _bi is the reactance value of the one-sided capacitor in the π-shaped equivalent circuit of line i, i=1,2,...,n;

The charging power Q _bi of line i is calculated by the following formula:

The reactive power Q _ki injected into the shunt reactor of line i is calculated by the following formula:

The reactive power injection quantity Q _L at the low-voltage side is calculated by the following formula:

In the formula:

X _L is the reactance value of the reactive device input on the low-voltage side.

Based on another aspect of the present invention, the present invention provides a reactive voltage control system, the system comprising:

An acquisition unit, used to acquire the bus voltage U _H on the high voltage side;

Judgment unit, used to judge the bus voltage U _H value on the high-voltage side:

时，调整所述高压侧母线电压U_H，使得所述高压侧母线电压U_H降低到预设的高压侧母线电压上限值

之下并且高压侧母线电压下限值

之上；或者When the high voltage side bus voltage U _H is greater than the preset high voltage side bus voltage upper limit

, adjust the high-voltage side bus voltage U _H so that the high-voltage side bus voltage U _H is reduced to the preset upper limit value of the high-voltage side bus voltage

below and the lower limit of the bus voltage on the high voltage side

above; or

时，调整所述高压侧母线电压U_H，使得所述高压侧母线电压U_H升高到预设的高压侧母线电压下限值

之上并且高压侧母线电压上限值

之下；When the high-voltage side bus voltage U _H is less than the preset lower limit value of the high-voltage side bus voltage

, adjust the high-voltage side bus voltage U _H so that the high-voltage side bus voltage U _H rises to the preset lower limit value of the high-voltage side bus voltage

above and the upper limit of the bus voltage on the high voltage side

under;

与高压侧母线电压下限值

之间时，计算高压侧所有线路中点处对局部系统的无功注入之和Q_H，计算中压侧对局部系统的无功注入之和Q_M，计算Q_H与Q_M的和Q_HM，判断Q_HM是否大于预设的局部系统无功需求平衡阈值Q_equi；When the high-voltage side bus voltage U _H is at the preset upper limit of the high-voltage side bus voltage

and the lower limit of the bus voltage on the high voltage side

When between, calculate the sum Q _H of the reactive power injected into the local system at the middle point of all lines on the high voltage side, calculate the sum Q _M of the reactive power injected into the local system at the medium voltage side, and calculate the sum Q _HM of Q _H and Q _M , to determine whether Q _HM is greater than the preset partial system reactive power demand balance threshold Q _equi ;

The local system reactive power is controlled based on Q _HM and the preset local system reactive power demand balance threshold Q _equi .

Preferably, the judging unit is used to control the reactive power of the local system based on Q _HM and the preset local system reactive power demand balance threshold Q _equi , and is also used for: when Q _HM is greater than the preset local system reactive power When the power demand balance threshold Q _equi is reached, a set of capacitive reactive power supplementary equipment is put in or a set of inductive reactive power compensation equipment is cut off;

When Q _HM is less than the negative number of the preset partial system reactive power demand balance threshold Q _equi , a set of inductive reactive power supplementary equipment is put in or a set of capacitive reactive power compensation equipment is removed;

When the negative number of the preset partial system reactive power demand balance threshold Q _equi is equal to Q _HM , the current operating state is maintained;

When Q _HM is less than the preset local system reactive power demand balance threshold Q _equi , and when Q _HM is greater than the negative number of the preset local system reactive power demand balance threshold Q _equi , and when all lines on the high-voltage side are at the midpoint The sum Q _H of the reactive power injection to the local system is greater than the reactive power ride-through threshold Q _thr of the local system, or the reactive power injection amount Q _M of the medium-voltage side of the local system is less than the negative number of the reactive power ride-through threshold Q _thr of the local system, and a group of Capacitive reactive power supplementary equipment or removal of a group of inductive reactive power compensation equipment;

Or when Q _HM is less than the preset local system reactive power demand balance threshold Q _equi , and when Q _HM is greater than the negative number of the preset local system reactive power demand balance threshold Q _equi , and when the midpoint of all lines on the high voltage side is The sum Q _H of the reactive power injection of the local system is less than the negative number of the reactive power ride-through threshold Q _thr of the local system, or the reactive power injection amount Q _M of the medium voltage side of the local system is greater than the reactive power ride-through threshold Q _thr of the local system, then a set of inductive Reactive power supplementary equipment or removal of a group of capacitive reactive power compensation equipment.

Preferably, the method for calculating the reactive power injection quantity Q _M of the medium-voltage side of the local system includes:

θi is the angle between the busbar voltage U _M on the medium voltage side and the switch current I _Mi on the outlet line _i on the medium voltage side.

Preferably, the calculation method of the sum Q _H of the reactive power injected into the local system at the midpoints of all lines on the high-voltage side includes:

Q _H ＝Q _dem -Q _L -Q _M

Among them, Q _dem is the reactive power demand of the local system, Q _M is the reactive power injection amount of the medium voltage side of the local system, and Q _L is the reactive power injection amount of the low voltage side of the local system.

Preferably, the calculation method of local system reactive power demand Q _dem includes:

I _Hi Line i high-voltage side outlet switch current;

I _li is the steady-state current of the line i impedance branch, i=1,2,...,n;

X _li is the reactance of line i, i=1,2,...,n;

X _ti is the leakage reactance of transformer i, i=1,2,...,m;

Q _bi is the charging power of half the length line i in the local system, i=1,2,...,n;

Q _ki is the high reactive power of line i, i=1,2,...,n;

The steady-state current I _li of the impedance branch of the line i is calculated by the following formula:

In the formula:

X _ki is the reactance value of the high reactance of line i, i=1,2,...,n;

j is the imaginary unit;

X _bi is the reactance value of the one-sided capacitor in the π-shaped equivalent circuit of line i, i=1,2,...,n;

The charging power Q _bi of line i is calculated by the following formula:

The reactive power Q _ki injected into the shunt reactor of line i is calculated by the following formula:

The reactive power injection quantity Q _L at the low-voltage side is calculated by the following formula:

In the formula:

X _L is the reactance value of the reactive device input on the low-voltage side.

The reactive power voltage control method proposed by the technical solution of the present invention can take into account both local system reactive power balance and reactive power ride-through, can accurately reflect the changing trend of local system reactive power demand with transmission power and load, and can respond to changes in system voltage in a timely manner. The influence of reactive power ride through can also be taken into account. The technical solution of the present invention solves the technical problem of quantitatively judging and controlling the reactive power demand of the local system and the system voltage change trend by only using local electrical measurement. , can quantitatively reflect the principle of reactive power local balance in the power system, has strong adaptability to operating conditions, and avoids the problem that the direct measurement of reactive power at the port cannot accurately reflect the reactive power demand of the system, and also avoids the relatively large error of voltage measurement Larger lead to poor regulation accuracy of steady-state reactive voltage. The technical scheme of the invention can accurately reflect and compensate the reactive power demand of the system, and can also take into account voltage safety emergency control and reactive power ride-through.

Description of drawings

A more complete understanding of the exemplary embodiments of the present invention can be had by referring to the following drawings:

Fig. 1 is a schematic diagram of "reactive voltage nine-zone diagram method" according to the prior art;

Fig. 2 is a flow chart of a reactive voltage control method according to a preferred embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a partial system according to a preferred embodiment of the present invention; and

Fig. 4 is a structural diagram of a reactive voltage control system according to a preferred embodiment of the present invention.

detailed description

Exemplary embodiments of the present invention will now be described with reference to the drawings; however, the present invention may be embodied in many different forms and are not limited to the embodiments described herein, which are provided for the purpose of exhaustively and completely disclosing the present invention. invention and fully convey the scope of the invention to those skilled in the art. The terms used in the exemplary embodiments shown in the drawings do not limit the present invention. In the figures, the same units/elements are given the same reference numerals.

Unless otherwise specified, the terms (including scientific and technical terms) used herein have the commonly understood meanings to those skilled in the art. In addition, it can be understood that terms defined by commonly used dictionaries should be understood to have consistent meanings in the context of their related fields, and should not be understood as idealized or overly formal meanings.

Fig. 1 is a flowchart of a reactive voltage control method according to a preferred embodiment of the present invention. The reactive voltage control method proposed by the present invention includes an outer layer voltage boundary emergency control method and an inner layer reactive power balance control method. Among them, the emergency control method of the outer voltage boundary includes: based on the bus voltage measurement, when the bus voltage exceeds the upper limit of operation, a set of inductive reactive power compensation equipment is quickly put in, or a set of capacitive reactive power compensation equipment is cut off to reduce the bus voltage. Ensure the safety of equipment in the substation; when the voltage exceeds the lower limit of operation, quickly put in a set of capacitive reactive power compensation equipment, or cut off a set of inductive reactive power compensation equipment, for reactive power emergency support, and increase the bus voltage. The priority of the outer layer voltage boundary emergency control is higher than that of the inner layer reactive power balance control. The inner layer control is blocked when the outer layer control is activated. When the bus voltage returns to a certain range, the inner layer control can be unlocked.

The inner layer reactive power balance control method includes: mainly based on branch current measurement, due to the relatively high measurement accuracy of the current transformer, it can ensure the high precision of the inner layer control, real-time calculation of local reactive power balance requirements, and take into account the reactive power requirements of ride-through , control the switching of reactive power compensation equipment, ensure local reactive power balance as much as possible, and reduce reactive power ride-through. If the absolute value of the reactive power demand of the local system is greater than the capacity of a group of reactive power adjustment equipment, switch a group of reactive power compensation equipment according to the reactive power demand; if the absolute value of the reactive power demand of the local system is smaller than the capacity of a group of reactive power adjustment equipment , but a large amount of cross-over reactive power flows from the high-voltage side to the medium-voltage side, and a set of capacitive reactive power compensation equipment is invested, or a set of inductive reactive power compensation equipment is withdrawn; if the absolute value of the reactive power demand of the local system is less than a set of reactive power adjustment equipment capacity, but a large amount of reactive power flows from the medium-voltage side to the high-voltage side, and a set of inductive reactive power compensation equipment is invested, or a set of capacitive reactive power compensation equipment is withdrawn.

As shown in Figure 1, the present invention provides a reactive voltage control method, the method includes:

In step 101: obtaining the high voltage side bus voltage U _H ;

The invention acquires local electrical parameters through measuring devices such as voltage transformers and current transformers in substations.

时，通过投入感性无功补充设备或切除容性无功补偿设备，调整高压侧母线电压U_H，使得高压侧母线电压U_H降低到预设的高压侧母线电压上限值

之下并且高压侧母线电压下限值

之上。In step 102: when the bus voltage U _H on the high voltage side is greater than the preset upper limit of the bus voltage on the high voltage side

When using inductive reactive power compensation equipment or removing capacitive reactive power compensation equipment, the high-voltage side bus voltage U _H is adjusted so that the high-voltage side bus voltage U _H is reduced to the preset high-voltage side bus voltage upper limit

below and the lower limit of the bus voltage on the high voltage side

above.

和下限值

越电压上下限恢复阈值

局部系统无功平衡阈值Q_equi，局部系统无功穿越阈值Q_thr。In the present invention, the reactive voltage control threshold parameter is input into the controller, including: the upper limit value of the busbar voltage on the high voltage side

and the lower limit

Over voltage upper and lower limit recovery threshold

Local system reactive power balance threshold Q _equi , local system reactive power crossing threshold Q _thr .

中压侧出线开关电流

低压侧母线电压U_L，高压侧母线电压

高压侧出线开关电流

The present invention reads in the local electrical quantities through the controller, including: bus voltage on the medium voltage side

Medium voltage side outlet switch current

Low-voltage side bus voltage U _L , high-voltage side bus voltage

High voltage side outlet switch current

迅速投入一组感性无功补偿设备，或切除一组容性无功补偿设备；当电压越外层电压运行下限时。When the bus voltage on the high-voltage side is greater than the upper limit of operation, that is

Quickly put in a set of inductive reactive power compensation equipment, or remove a set of capacitive reactive power compensation equipment; when the voltage exceeds the lower limit of the outer voltage operation.

时，通过投入容性无功补充设备或切除感性无功补偿设备，调整高压侧母线电压U_H，使得高压侧母线电压U_H升高到预设的高压侧母线电压下限值

之上并且高压侧母线电压上限值

之下。In step 103: when the bus voltage U _H on the high voltage side is less than the preset lower limit value of the bus voltage on the high voltage side

, adjust the bus voltage U _H on the high-voltage side by putting in capacitive reactive power supplementary equipment or removing inductive reactive power compensation equipment, so that the bus voltage U _H on the high-voltage side rises to the preset lower limit of the high-voltage side bus voltage

above and the upper limit of the bus voltage on the high voltage side

under.

迅速投入一组容性无功补偿设备，或切除一组感性无功补偿设备。The present invention should

Quickly put in a set of capacitive reactive power compensation equipment, or remove a set of inductive reactive power compensation equipment.

与高压侧母线电压下限值

之间时，计算高压侧所有线路中点处对局部系统的无功注入之和Q_H，计算中压侧对局部系统的无功注入之和Q_M，计算Q_H与Q_M的和Q_HM，判断Q_HM的绝对值是否大于预设的局部系统无功需求平衡阈值Q_equi。In step 104: when the bus voltage U _H on the high voltage side is within the preset upper limit of the bus voltage on the high voltage side

and the lower limit of the bus voltage on the high voltage side

When between, calculate the sum Q _H of the reactive power injected into the local system at the middle point of all lines on the high voltage side, calculate the sum Q _M of the reactive power injected into the local system at the medium voltage side, and calculate the sum Q _HM of Q _H and Q _M , to determine whether the absolute value of Q _HM is greater than a preset partial system reactive power demand balance threshold Q _equi .

Preferably, the calculation method for the reactive power injection quantity Q _M of the medium voltage side of the local system includes:

θi is the angle between the busbar voltage U _M on the medium voltage side and the switch current I _Mi on the outlet line _i on the medium voltage side.

Preferably, the calculation method of the sum Q _H of the reactive power injected into the local system at the midpoints of all lines on the high-voltage side includes:

Q _H ＝Q _dem -Q _L -Q _M

Among them, Q _dem is the reactive power demand of the local system, Q _M is the reactive power injection amount of the medium voltage side of the local system, and Q _L is the reactive power injection amount of the low voltage side of the local system.

Preferably, the calculation method of local system reactive power demand Q _dem includes:

I _Hi Line i high-voltage side outlet switch current;

I _li is the steady-state current of the line i impedance branch, i=1,2,...,n;

X _li is the reactance of line i, i=1,2,...,n;

X _ti is the leakage reactance of transformer i, i=1,2,...,m;

Q _bi is the charging power of half the length line i in the local system, i=1,2,...,n;

Q _ki is the high reactive power of line i, i=1,2,...,n;

The steady-state current I _li of the impedance branch of the line i is calculated by the following formula:

In the formula:

X _ki is the reactance value of the high reactance of line i, i=1,2,...,n;

j is the imaginary unit;

X _bi is the reactance value of the one-sided capacitor in the π-shaped equivalent circuit of line i, i=1,2,...,n;

The charging power Q _bi of line i is calculated by the following formula:

The reactive power Q _ki injected into the shunt reactor of line i is calculated by the following formula:

The reactive power injection quantity Q _L on the low-voltage side is calculated by the following formula:

In the formula:

X _L is the reactance value of the reactive device input on the low-voltage side.

According to the principle of reactive power balance of the system, the present invention calculates the sum Q _H of the reactive power injected into the local system at the midpoint of all lines on the high voltage side, and calculates the sum Q of the reactive power injected Q _M of the medium voltage side of the local system and Q _{H HM} , judging whether Q _HM is greater than a preset partial system reactive power demand balance threshold Q _equi .

The reactive power demand Q _dem of the local system is calculated by formula (1):

In the formula:

Q _dem is the reactive power demand of the local system;

The reactive power injection quantity Q _M at the low-voltage side is calculated by formula (2):

In the formula:

与中压侧出线i电流

的夹角。 _θi is the voltage on the medium voltage side

and the medium voltage side outlet i current

angle.

In step 2:

The sum Q _H of reactive power injection to the local system at the midpoint of all lines on the high-voltage side is calculated by formula (3):

Q _H ＝Q _dem -Q _L -Q _M (3)

In step 105 : controlling the local system reactive power based on Q _HM and a preset local system reactive power demand balance threshold Q _equi .

Preferably, when Q _HM is greater than the preset local system reactive power demand balance threshold Q _equi , a set of capacitive reactive power supplementary equipment is put into operation or a set of inductive reactive power compensation equipment is cut off.

In the present invention, if Q _H +Q _M >Q _equi , a set of capacitive reactive power compensation equipment is put in or a set of inductive reactive power compensation equipment is removed.

Preferably, when Q _HM is smaller than the negative number Q _HM of the preset local system reactive demand balance threshold Q _equi , a set of inductive reactive power supplementary equipment is put into use or a set of capacitive reactive power compensation equipment is cut off.

In the present invention, if Q _H +Q _M <-Q _equi , a set of inductive reactive power compensation equipment is put in or a set of capacitive reactive power compensation equipment is removed.

Preferably, when the negative number of the preset partial system reactive demand balance threshold Q _equi is equal to Q _HM , the current running state is maintained.

Preferably, when Q _HM is less than the preset local system reactive power demand balance threshold Q _equi , and when Q _HM is greater than the negative number of the preset local system reactive power demand balance threshold Q _equi , and when the midpoint of all lines on the high voltage side The sum Q _H of reactive power injection to the local system is greater than the local system reactive power ride-through threshold Q _thr , or the reactive power injection amount Q _M of the medium voltage side of the local system is less than the negative number of the local system reactive power ride-through threshold Q _thr , then a Group capacitive reactive power supplementary equipment or remove a group of inductive reactive power compensation equipment.

In the present invention, if Q _H >Q _thr or Q _M <-Q _thr , a set of capacitive reactive power supplementary equipment is put in or a set of inductive reactive power compensation equipment is removed.

Or when Q _HM is less than the preset local system reactive power demand balance threshold Q _equi , and when Q _HM is greater than the negative number of the preset local system reactive power demand balance threshold Q _equi , when the midpoint of all lines on the high-voltage side The sum of reactive power injection Q _H of the system is less than the negative number of the reactive power ride-through threshold Q _thr of the local system, or the reactive power injection amount Q _M of the medium-voltage side of the local system is greater than the reactive power ride-through threshold Q _thr of the local system, and a set of inductive reactive power is put into use. Power supplementary equipment or remove a set of capacitive reactive power compensation equipment.

If Q _H <-Q _thr or Q _M >Q _thr , put in a set of inductive reactive compensation equipment or remove a set of capacitive reactive compensation equipment.

The local system in the present invention is composed of a transformer, a half-length high-voltage side outlet of the transformer, and a shunt reactor for the high-voltage side outlet, as shown in FIG. 3 .

The present invention uses high-precision current measurement to calculate the reactive power demand of the system in real time, which can quantitatively reflect the principle of in-situ reactive power balance in the power system, significantly improves the adaptability to changes in the operating conditions of the system, and avoids direct reactive power at the port. The problem that the measurement cannot accurately reflect the reactive power demand of the system can effectively suppress the voltage change caused by the active power fluctuation in a timely manner.

Combining the inner reactive power control based on current measurement with the outer layer control based on the bus voltage boundary, it not only considers the local characteristics of reactive power balance, but also takes into account the global characteristics of the system operating voltage change trend, and can realize local reactive power control It is effectively coordinated with the global voltage control, and avoids the problem of relatively large voltage measurement error resulting in poor accuracy of quasi-steady-state reactive voltage regulation.

The reactive power voltage control method that can take into account the reactive power balance and reactive power ride-through of the local system can accurately reflect the changing trend of the reactive power demand of the local system with the transmission power and load, and can respond to changes in the system voltage in a timely manner. It can also take into account reactive power. The impact of power ride-through can be well adapted to the reactive voltage characteristics of the pure new energy transmission system.

In another embodiment of the present invention, current measurement can be replaced by active power measurement. The reactive power injection at the reactive power balance boundary of the high-voltage line can be calculated from the local voltage and current measurement and the line impedance.

Fig. 4 is a structural diagram of a reactive voltage control system according to a preferred embodiment of the present invention. As shown in Figure 4, the present invention provides a reactive voltage control system, the system includes:

An acquisition unit 401, configured to acquire the bus voltage U _H on the high voltage side;

Judging unit 402, used to judge the bus voltage U _H value on the high voltage side:

时，调整高压侧母线电压U_H，使得高压侧母线电压U_H降低到预设的高压侧母线电压上限值

之下并且高压侧母线电压下限值

之上；或者When the bus voltage U _H on the high voltage side is greater than the preset upper limit of the bus voltage on the high voltage side

When , adjust the bus voltage U _H on the high-voltage side so that the bus voltage U _H on the high-voltage side is reduced to the preset upper limit of the bus voltage on the high-voltage side

below and the lower limit of the bus voltage on the high voltage side

above; or

时，调整高压侧母线电压U_H，使得高压侧母线电压U_H升高到预设的高压侧母线电压下限值

之上并且高压侧母线电压上限值

之下；When the bus voltage U _H on the high-voltage side is less than the preset lower limit of the bus voltage on the high-voltage side

When , adjust the bus voltage U _H on the high voltage side so that the bus voltage U _H on the high voltage side rises to the preset lower limit of the bus voltage on the high voltage side

above and the upper limit of the bus voltage on the high voltage side

under;

与高压侧母线电压下限值

之间时，计算高压侧所有线路中点处对局部系统的无功注入之和Q_H，计算中压侧对局部系统的无功注入之和Q_M，计算Q_H与Q_M的和Q_HM，判断Q_HM是否大于预设的局部系统无功需求平衡阈值Q_equi；When the high-voltage side bus voltage U _H is at the preset high-voltage side bus voltage upper limit

and the lower limit of the bus voltage on the high voltage side

When between, calculate the sum Q _H of the reactive power injected into the local system at the middle point of all lines on the high voltage side, calculate the sum Q _M of the reactive power injected into the local system at the medium voltage side, and calculate the sum Q _HM of Q _H and Q _M , to determine whether Q _HM is greater than the preset partial system reactive power demand balance threshold Q _equi ;

The local system reactive power is controlled based on Q _HM and the preset local system reactive power demand balance threshold Q _equi .

Preferably, the judging unit is used to control the local system reactive power based on Q _HM and the preset local system reactive power demand balance threshold Q _equi , and is also used for: when Q _HM is greater than the preset local system reactive power demand balance threshold When Q _equi , put in a set of capacitive reactive power supplementary equipment or remove a set of inductive reactive power compensation equipment;

When Q _HM is less than the negative number Q _HM of the preset partial system reactive power demand balance threshold Q _equi , a set of inductive reactive power supplementary equipment is put in or a set of capacitive reactive power compensation equipment is removed;

When the negative number of the preset partial system reactive demand balance threshold Q _equi is equal to Q _HM , the current running state is maintained.

When Q _HM is less than the preset local system reactive power demand balance threshold Q _equi , and when Q _HM is greater than the negative number of the preset local system reactive power demand balance threshold Q _equi , and when The sum of reactive power injection Q _H of the system is greater than the reactive power ride-through threshold Q _thr of the local system, or the reactive power injection amount Q _M of the medium-voltage side of the local system is less than the negative number of the reactive power ride-through threshold Q _thr of the local system, and a set of capacitive power is put into use. Reactive power supplementary equipment or removal of a group of inductive reactive power compensation equipment;

Or when Q _HM is less than the preset local system reactive power demand balance threshold Q _equi , and when Q _HM is greater than the negative number of the preset local system reactive power demand balance threshold Q _equi , and when the midpoint of all lines on the high voltage side is The sum Q _H of the reactive power injection of the local system is less than the negative number of the reactive power ride-through threshold Q _thr of the local system, or the reactive power injection amount Q _M of the medium voltage side of the local system is greater than the reactive power ride-through threshold Q _thr of the local system, then a set of inductive Reactive power supplementary equipment or removal of a group of capacitive reactive power compensation equipment.

Preferably, the calculation method for the reactive power injection quantity Q _M of the medium voltage side of the local system includes:

θi is the angle between the busbar voltage U _M on the medium voltage side and the switch current I _Mi on the outlet line _i on the medium voltage side.

Preferably, the calculation method of the sum Q _H of the reactive power injected into the local system at the midpoints of all lines on the high-voltage side includes:

Q _H ＝Q _dem -Q _L -Q _M

Among them, Q _dem is the reactive power demand of the local system, Q _M is the reactive power injection amount of the medium voltage side of the local system, and Q _L is the reactive power injection amount of the low voltage side of the local system.

Preferably, the calculation method of local system reactive power demand Q _dem includes:

I _Hi Line i high-voltage side outlet switch current;

I _li is the steady-state current of the line i impedance branch, i=1,2,...,n;

X _li is the reactance of line i, i=1,2,...,n;

X _ti is the leakage reactance of transformer i, i=1,2,...,m;

Q _bi is the charging power of half the length line i in the local system, i=1,2,...,n;

Q _ki is the high reactive power of line i, i=1,2,...,n;

The steady-state current I _li of the impedance branch of the line i is calculated by the following formula:

In the formula:

X _ki is the reactance value of the high reactance of line i, i=1,2,...,n;

j is the imaginary unit;

X _bi is the reactance value of the one-sided capacitor in the π-shaped equivalent circuit of line i, i=1,2,...,n;

The charging power Q _bi of line i is calculated by the following formula:

The reactive power Q _ki injected into the shunt reactor of line i is calculated by the following formula:

The reactive power injection quantity Q _L at the low-voltage side is calculated by the following formula:

In the formula:

X _L is the reactance value of the reactive device input on the low-voltage side.

A reactive voltage control system 400 according to a preferred embodiment of the present invention corresponds to a reactive voltage control method 200 according to another preferred embodiment of the present invention, and details are not repeated here.

Those skilled in the art should understand that the embodiments of the present application may be provided as methods, systems, or computer program products. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) having computer-usable program code embodied therein.

The present application is described with reference to flowcharts and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present application. It should be understood that each procedure and/or block in the flowchart and/or block diagram, and a combination of procedures and/or blocks in the flowchart and/or block diagram can be realized by computer program instructions. These computer program instructions may be provided to a general purpose computer, special purpose computer, embedded processor, or processor of other programmable data processing equipment to produce a machine such that the instructions executed by the processor of the computer or other programmable data processing equipment produce a An apparatus for realizing the functions specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing apparatus to operate in a specific manner, such that the instructions stored in the computer-readable memory produce an article of manufacture comprising instruction means, the instructions The device realizes the function specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions can also be loaded onto a computer or other programmable data processing device, causing a series of operational steps to be performed on the computer or other programmable device to produce a computer-implemented process, thereby The instructions provide steps for implementing the functions specified in the flow diagram procedure or procedures and/or block diagram procedures or blocks.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: the present invention can still be Any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention shall fall within the protection scope of the claims of the present invention.

The invention has been described with reference to a small number of embodiments. However, it is clear to a person skilled in the art that other embodiments than the invention disclosed above are equally within the scope of the invention, as defined by the appended patent claims.

Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise therein. All references to "a/the/the [means, component, etc.]" are openly construed to mean at least one instance of said means, component, etc., unless expressly stated otherwise. The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless explicitly stated.

Claims (8)

1. A reactive voltage control method, said method comprising: Obtain the bus voltage U _H on the high voltage side; When the high voltage side bus voltage U _H is greater than the preset high voltage side bus voltage upper limit

, adjust the high-voltage side bus voltage U _H so that the high-voltage side bus voltage U _H is reduced to the preset upper limit value of the high-voltage side bus voltage

below and the lower limit of the bus voltage on the high voltage side

above; or When the high-voltage side bus voltage U _H is less than the preset lower limit value of the high-voltage side bus voltage

, adjust the high-voltage side bus voltage U _H so that the high-voltage side bus voltage U _H rises to the preset lower limit value of the high-voltage side bus voltage

above and the upper limit of the bus voltage on the high voltage side

under; When the high-voltage side bus voltage U _H is at the preset upper limit of the high-voltage side bus voltage

and the lower limit of the bus voltage on the high voltage side

When between, calculate the sum Q _H of the reactive power injected into the local system at the middle point of all lines on the high voltage side, calculate the sum Q _M of the reactive power injected into the local system at the medium voltage side, and calculate the sum Q _HM of Q _H and Q _M , to determine whether the absolute value of Q _HM is greater than the preset partial system reactive power demand balance threshold Q _equi ; Based on Q _HM and the preset local system reactive power demand balance threshold Q _equi to control the local system reactive power, it also includes: When Q _HM is greater than the preset partial system reactive power demand balance threshold Q _equi , a set of capacitive reactive power supplementary equipment is put in or a set of inductive reactive power compensation equipment is removed; When Q _HM is less than the negative number of the preset partial system reactive power demand balance threshold Q _equi , a set of inductive reactive power supplementary equipment is put in or a set of capacitive reactive power compensation equipment is removed; When the negative number of the preset partial system reactive power demand balance threshold Q _equi is equal to Q _HM , the current operating state is maintained; When Q _HM is less than the preset local system reactive power demand balance threshold Q _equi , and when Q _HM is greater than the negative number of the preset local system reactive power demand balance threshold Q _equi , and when all lines on the high-voltage side are at the midpoint The sum Q _H of the reactive power injection to the local system is greater than the reactive power ride-through threshold Q _thr of the local system, or the reactive power injection amount Q _M of the medium-voltage side of the local system is less than the negative number of the reactive power ride-through threshold Q _thr of the local system, and a group of Capacitive reactive power supplementary equipment or removal of a group of inductive reactive power compensation equipment; Or when Q _HM is less than the preset local system reactive power demand balance threshold Q _equi , and when Q _HM is greater than the negative number of the preset local system reactive power demand balance threshold Q _equi , when the local The sum of reactive power injection Q _H of the system is less than the negative number of the reactive power ride-through threshold Q _thr of the local system, or the reactive power injection amount Q _M of the medium-voltage side of the local system is greater than the reactive power ride-through threshold Q _thr of the local system, and a set of inductive reactive power is put into use. Power supplementary equipment or remove a set of capacitive reactive power compensation equipment. 2. The method of claim 1, The method for calculating the reactive power injection quantity Q _M of the medium-voltage side of the local system includes:

θi is the angle between the busbar voltage U _M on the medium voltage side and the switch current I _Mi on the outlet line _i on the medium voltage side. 3. The method of claim 1, The calculation method of the sum Q _H of the reactive power injection to the local system at the midpoint of all lines on the high-voltage side includes: Q _H ＝Q _dem -Q _L -Q _M Among them, Q _dem is the reactive power demand of the local system, Q _M is the reactive power injection amount of the medium voltage side of the local system, and Q _L is the reactive power injection amount of the low voltage side of the local system. 4. The method according to claim 3, the calculation method of local system reactive power demand Q _dem comprises:

I _Hi Line i high-voltage side outlet switch current; I _li is the steady-state current of the line i impedance branch, i=1,2,...,n; X _li is the reactance of line i, i=1,2,...,n; X _ti is the leakage reactance of transformer i, i=1,2,...,m; Q _bi is the charging power of half the length line i in the local system, i=1,2,...,n; Q _ki is the high reactive power of line i, i=1,2,...,n; The steady-state current I _li of the impedance branch of the line i is calculated by the following formula:

In the formula: X _ki is the reactance value of the high reactance of line i, i=1,2,...,n; j is the imaginary unit; X _bi is the reactance value of the one-sided capacitor in the π-shaped equivalent circuit of line i, i=1,2,...,n; The charging power Q _bi of line i is calculated by the following formula:

The reactive power Q _ki injected into the shunt reactor of line i is calculated by the following formula:

The reactive power injection quantity Q _L at the low-voltage side is calculated by the following formula:

In the formula: X _L is the reactance value of the reactive device input on the low-voltage side. 5. A reactive voltage control system, said system comprising: An acquisition unit, used to acquire the bus voltage U _H on the high voltage side; Judgment unit, used to judge the bus voltage U _H value on the high-voltage side: When the high voltage side bus voltage U _H is greater than the preset high voltage side bus voltage upper limit

, adjust the high-voltage side bus voltage U _H so that the high-voltage side bus voltage U _H is reduced to the preset upper limit value of the high-voltage side bus voltage

below and the lower limit of the bus voltage on the high voltage side

above; or When the high-voltage side bus voltage U _H is less than the preset lower limit value of the high-voltage side bus voltage

, adjust the high-voltage side bus voltage U _H so that the high-voltage side bus voltage U _H rises to the preset lower limit value of the high-voltage side bus voltage

above and the upper limit of the bus voltage on the high voltage side

under; When the high-voltage side bus voltage U _H is at the preset upper limit of the high-voltage side bus voltage

and the lower limit of the bus voltage on the high voltage side

When between, calculate the sum Q _H of the reactive power injected into the local system at the middle point of all lines on the high voltage side, calculate the sum Q _M of the reactive power injected into the local system at the medium voltage side, and calculate the sum Q _HM of Q _H and Q _M , to determine whether Q _HM is greater than the preset partial system reactive power demand balance threshold Q _equi ; Based on Q _HM and the preset local system reactive power demand balance threshold Q _equi to control the local system reactive power, it is also used when Q _HM is greater than the preset local system reactive power demand balance threshold Q _equi , a group of Capacitive reactive power supplementary equipment or removal of a group of inductive reactive power compensation equipment; When Q _HM is less than the negative number of the preset partial system reactive power demand balance threshold Q _equi , a set of inductive reactive power supplementary equipment is put in or a set of capacitive reactive power compensation equipment is removed; When the negative number of the preset partial system reactive power demand balance threshold Q _equi is equal to Q _HM , the current operating state is maintained; When Q _HM is less than the preset local system reactive power demand balance threshold Q _equi , and when Q _HM is greater than the negative number of the preset local system reactive power demand balance threshold Q _equi , and when all lines on the high-voltage side are at the midpoint The sum Q _H of the reactive power injection to the local system is greater than the reactive power ride-through threshold Q _thr of the local system, or the reactive power injection amount Q _M of the medium-voltage side of the local system is less than the negative number of the reactive power ride-through threshold Q _thr of the local system, and a group of Capacitive reactive power supplementary equipment or removal of a group of inductive reactive power compensation equipment; Or when Q _HM is less than the preset local system reactive power demand balance threshold Q _equi , and when Q _HM is greater than the negative number of the preset local system reactive power demand balance threshold Q _equi , and when the midpoint of all lines on the high voltage side is The sum Q _H of the reactive power injection of the local system is less than the negative number of the reactive power ride-through threshold Q _thr of the local system, or the reactive power injection amount Q _M of the medium voltage side of the local system is greater than the reactive power ride-through threshold Q _thr of the local system, then a set of inductive Reactive power supplementary equipment or removal of a group of capacitive reactive power compensation equipment. 6. The system according to claim 5, the calculation method of the reactive power injection quantity _QM at the medium pressure side of the local system comprises:

θi is the angle between the busbar voltage U _M on the medium voltage side and the switch current I _Mi on the outlet line _i on the medium voltage side. 7. The system according to claim 5, the calculation method of the sum Q _H of the reactive power injection to the local system at the midpoint of all lines on the high-voltage side comprises: Q _H ＝Q _dem -Q _L -Q _M Among them, Q _dem is the reactive power demand of the local system, Q _M is the reactive power injection amount of the medium voltage side of the local system, and Q _L is the reactive power injection amount of the low voltage side of the local system. 8. The system according to claim 7, the calculation method of local system reactive demand Q _dem comprises:

I _Hi Line i high-voltage side outlet switch current; I _li is the steady-state current of the line i impedance branch, i=1,2,...,n; X _li is the reactance of line i, i=1,2,...,n; X _ti is the leakage reactance of transformer i, i=1,2,...,m; Q _bi is the charging power of half the length line i in the local system, i=1,2,...,n; Q _ki is the high reactive power of line i, i=1,2,...,n; The steady-state current I _li of the impedance branch of the line i is calculated by the following formula:

In the formula: X _ki is the reactance value of the high reactance of line i, i=1,2,...,n; j is the imaginary unit; X _bi is the reactance value of the one-sided capacitor in the π-shaped equivalent circuit of line i, i=1,2,...,n; The charging power Q _bi of line i is calculated by the following formula:

The reactive power Q _ki injected into the shunt reactor of line i is calculated by the following formula:

The reactive power injection quantity Q _L on the low-voltage side is calculated by the following formula:

In the formula: X _L is the reactance value of the reactive device input on the low-voltage side.

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