JP3315181B2 - Series compensator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a series compensator for inserting at least a capacitor in series into a power system to compensate for reactance of the power system.

[0002]

2. Description of the Related Art In general, system reactance is known as one of the factors that determine the stability and transmission capacity of a power system. When transmitting a certain amount of power, if the reactance of the system is large, it is necessary to increase the phase difference angle between the generators at various points in the system as compared with the case where the reactance is small. The degree will decrease. The transmitted power P that is determined by Teitai stability is the reactance of the system X _L, V ₁ and V ₂ the voltage of the system across, when the phase difference angle of the line at both ends was [delta], is represented by the numerical formula 1, line Is large, the transmission power P is limited.

[0003]

[Number 1] where _{P = V 1 × V 2 ×} sinδ / X L, in order to compensate for the reactance of the system as described in the electrical joint research Vol. 34, No. 5 page 202, insert the capacitor to the system in series Then, a method of improving the stability of the system and increasing the transmission capacity has been proposed.

[0004]

However, in the conventional series compensator described above, the degree of compensating the reactance of the system, that is, the degree of compensation is fixed, and the entire apparatus is inserted into the system using a mechanical switch mechanism. Alternatively, it is only possible to select whether the entire apparatus is separated from the system, and it is difficult to optimize system control. On the other hand, a circuit configuration in which a series connection of a semiconductor switch and a reactor is connected in parallel with a capacitor is being studied, but in each case, the series compensator is an air-insulated system, and the influence of the surrounding environment is affected. Subject to safety and reliability issues. In addition, when the air insulation method is adopted, the entire device must be supported by insulating supports such as insulators at a height higher than the insulation of the system voltage with respect to the ground. If the weight of the steel is more than tens of tons, it becomes difficult to secure and support sufficient seismic strength.

[0005] It is an object of the present invention to provide a series compensator in which insulation to the ground is easy and stability of system control is improved.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a series compensator in which at least a capacitor for compensating reactance of a power system is inserted in series with the power system. , While connecting the series connected semiconductor switch and reactor ,
The capacitor, the semiconductor switch and the rear
And each in a gas-sealed closed container,
Insulation medium was placed in each of these closed containers
The features, (claim 1), also the capacitor and electrostatic
Semiconductor switches and reactors connected in series in gas parallel
Connect at least the above capacitor and put the insulation medium
Stored in a sealed container,
A bypass switch is provided in parallel in
That an open / close switch is connected between the switch and the capacitor
Characterized by (Claim 2), further, the capacitor and the electrostatic
Semiconductor switches and reactors connected in series in gas parallel
And the capacitor and the semiconductor switch.
Switch and the above-mentioned reactor in separate sealed containers
And between the above-mentioned closed containers through the respective outlets.
Communication, and furthermore, an insulation medium
(Claim 3) .

[0007]

The series compensator according to the present invention can change the degree of compensation for the reactance of the power system by controlling the opening and closing of the semiconductor switch electrically connected in parallel with the capacitor as described above. The degree of compensation can be set to an optimum value in accordance with the condition, and by storing the battery in a closed container filled with an insulating medium, ground insulation is facilitated and the charged portion is not exposed, so that reliability is improved and the size is reduced. Each of the above components is divided
Each closed container has its own structure.
Different or desirable filling pressures for components
(Claim 1) .
Provide a bypass switch electrically in parallel with the capacitor,
Open / close switch between this bypass switch and capacitor
Closed the bypass switch and connected the capacitor
By opening both open / close switches,
Parts requiring maintenance and inspection, such as body switches, are separated from the system.
After that, the part is grounded and the work is safe.
It can be performed completely (claim 2), and furthermore, each component
Elements are housed in separate closed containers interconnected at each outlet.
So each closed container is sized according to each component.
Can be formed and transported by separating each closed container
Not only for the production of closed containers, but also for transportation, etc.
It becomes easy (claim 3).

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic configuration diagram showing a series compensator according to an embodiment of the present invention.

[0010] Capacitor 1 which is inserted at both ends by a pair of bushings 7 series compensator connected in series to the grid, in series to the system to compensate for the reactance of transmission lines
An overvoltage protection device 4 connected in parallel to protect the capacitor 1 from overvoltage, a bypass switch 5 connected in parallel to the capacitor 1 to short-circuit both ends of the capacitor 1, and connected in parallel to the capacitor 1 And a series-connected body of a semiconductor switch 2 and a reactor 3 which are configured using a semiconductor element and can control an alternating current.
The overvoltage protection device 4 includes a non-linear element such as a zinc oxide element, a discharge gap, and the like, and the bypass switch 5 includes a mechanical switch, a semiconductor switch, and the like. The semiconductor switch 2 includes a switching semiconductor element such as a thyristor, a light-ignition thyristor, and a gate turn-off thyristor, a snubber circuit (not shown), and an overvoltage / overcurrent protection element. Stores each of these components
The configuration of the closed container 6 is as follows.
Containers 6a, 6b, 6c, 6d are formed, and inside closed container 6a.
Accommodates the bypass switch 5 in the closed container 6b.
The overvoltage protection device 4 is housed in the closed container 6c.
Sensor 1 and a semiconductor switch in the closed container 6d.
The switch 2 and the reactor 3 are housed. Each of these components
The conductors that electrically connect the elements are each a closed container 6a, 6
b, 6c, and 6d, respectively, led-out portions 10a, 1
0b, 10c, and each of these outlet portions 10a, 10c.
b, 10c, between each closed container 6a, 6b, 6c, 6d
To form one closed container 6 as a whole.
You. The sealed container 6 configured as described above is filled with an insulating medium such as a non-conductive gas or liquid such as sulfur hexafluoride gas, dry air, nitrogen gas, insulating oil, or nonflammable liquid. The sealed container 6 is made of a conductive member and grounded, and the components inside the sealed container 6 are supported in a state of being electrically insulated from the sealed container 6 by an insulating member (not shown). The insulating medium in the closed container 6 not only increases the insulation strength between the internal components and the closed container 6, but also
In particular, it is used as a cooling medium for positively suppressing heat generation due to the passage of current as in the semiconductor switch 2.

According to the series compensator having the above-described structure, the capacitor 1 is removed from the system by closing the bypass switch 5 and short-circuiting both ends of the capacitor 1, or the capacitor 1 is inserted into the system by opening the bypass switch 5. In addition to this, it is possible to control the degree of compensation by switching control of the semiconductor switch 2. Moreover, since the semiconductor switch 2 can easily perform a repetitive operation at a high speed, it is possible to perform fine control such that an optimum power flow state is obtained with respect to a power flow that changes every moment. Also, each
The closed containers 6a, 6b, 6c, 6d
It can be formed in a size corresponding to the components to be stored
After that, flush each of the outlets 10a, 10b, 10c.
Provision of means for connecting while maintaining airtightness
To form a single closed container 6 communicating with each other.
Can be. Therefore, cut with a connecting means such as a flange.
It can also be transported separately, and the closed containers 6a, 6b, 6
Not only the production of c and 6d, but also the transportation becomes easy. Further
In FIG. 1, each closed container 6a, 6b, 6c, 6d is vertically
Although they were arranged in a stack and connected between each other,
Each closed container 6a, 6b, 6c, 6d is arranged on the same horizontal plane
Or stack them in two layers and then connect them together.
It is possible to take a configuration in which flexibility can be obtained even when attaching.

FIG. 2 is a schematic configuration diagram of a series compensator according to another embodiment of the present invention. The same components as those in FIG. 1 are denoted by the same reference numerals and description thereof is omitted, and only different portions will be described. I do.

When the bypass switch 5 is closed in the configuration shown in FIG. 1, both ends of the capacitor 1 are short-circuited and the series compensation is not performed. However, the series compensation device is not separated from the system. Therefore, when performing maintenance and inspection of the semiconductor switch 2 and the like, power transmission must be stopped. Therefore, as shown in FIG.
The capacitor 1 is connected to both ends of the
Etc. are connected. Each component is a common closed container
6 and filled with an insulating medium in the closed container 6.
Have been.

With such a circuit configuration, when the bypass switch 5 is closed to bypass the capacitor 1 and the two on / off switches 8 are opened, the parts requiring maintenance and inspection such as the semiconductor switch 2 are separated from the system. After that, the part can be grounded and the work can be performed safely.

[0015]

[0016]

[0017]

[0018]

[0019]

FIG. 3 is a schematic structural view of a series compensator according to still another embodiment of the present invention. In the embodiment shown in FIG. 1 , the semiconductor switch 2 and the reactor 3 are both housed in a closed container 6d. In contrast, a pair of vertical sealed containers 6e and 6
f are arranged facing each other, the semiconductor switch 2 is arranged in the sealed container 6e, the reactor 3 is arranged in the sealed container 6f, and the airtightness such as a joint is maintained between the sealed containers 6e and 6f. They are connected by an outlet 10e having a connecting means. Other configurations are the same as those of the embodiment shown in FIG. 1. With such a configuration, the same effects as those of the embodiment can be obtained.

FIG. 4 is a schematic structural view of a series compensator according to still another embodiment of the present invention. In the embodiment shown in FIG. 1 , the condenser 1 is entirely housed in a closed container 6c. , A relatively large capacitor 1 is housed separately. That is, between the closed containers 6b and 6d,
A sealed container 6c1, axially connected by an outlet 10f having means for connecting and maintaining airtightness such as a joint.
6c2 and hermetically sealed containers 6c3 and 6c4 axially connected by an outlet 10g having means for airtight connection such as a joint.
A lead portion 10d between 1 and 6c3 and between 6c2 and 6c4
And these closed containers 6c1, 6c
Capacitors 1a, 1b, 1c, and 1d divided and arranged in c2, 6c3, and 6c4 are distributed. Other configurations are the same as those of the embodiment shown in FIG. Although not limited to the capacitor 1 to configure divided and, in particular, in the series compensator is often the volume of the capacitor 1 is increased as compared with other components, some the entire capacitor as shown in FIG. 4 By dividing into two and storing in a closed container, a standard closed container can be used without manufacturing a specially large closed container.

[0022] Figure 5 is a side view showing a schematic configuration diagram of a series compensator according to yet another embodiment of the present invention, FIG. 1 described above
The closed containers 6a, 6b, 6c, 6d shown in FIG. 1 are juxtaposed substantially in parallel on an installation surface. When the installation place is relatively large, by arranging the closed containers 6a, 6b, 6c, 6d horizontally, the height of the device can be reduced, and the device can be stably installed to improve the earthquake resistance. However, since the general location is limited, the sealed container 6a as shown in FIG. 6, 6b, 6c, had better be disposed stacked stage structure with 6d to be arranged horizontally. However, at this time, it is advisable to arrange a closed container for components that are heavy in weight or components that require relatively frequent maintenance and inspection near the installation surface.

In the above series compensator, for example, a pair of bushings 7 are established in a closed vessel 6 as shown in FIG. 1 and connected to the system via the bushings 7. In some cases, it is incorporated into a distribution and substation facility configured with a gas insulated switchgear. In this case, the sealed container of the series compensator, be configured to connect portions for connecting <br/> directly sealed container distribution substation equipment gas insulated switchgear rather than a bushing mounted, series compensator And integrated distribution and substation equipment. For example, Figure 7
A bushing 22 provided at one end of a gas insulated switchgear is connected to a power transmission line 21 as in a substation with a circuit diagram written therein,
Series compensator 2 between gas circuit breaker 23 and gas insulated bus 24
5, a transformer 27 can be connected to the other end of the gas insulated switchgear via a gas circuit breaker 26. In the case of an intermediate switchyard with a circuit diagram also shown in FIG. 8 , a bushing 22a provided at one end of a gas insulated switchgear is connected to two transmission lines 21a, and a gas circuit breaker 23 is connected.
a and a gas-insulated bus 24a, and a bushing 22 at the other end of the gas-insulated switchgear having a common series compensator 25 connected between the gas circuit breaker 23b and the gas-insulated bus 24b.
By connecting to the two transmission lines 21b via b, the reactance of the two transmission lines 21a and 21b can be compensated collectively. According to such a distribution and substation facility, even in a series compensator, the charging part conductor can be arranged in a closed container having a ground potential to eliminate exposure to the outside. There is no loss of reliability.

In each of the embodiments shown in FIGS. 1 , 3 , 4 , 5, and 6 above, the inside of each closed container is constituted by gas communication, but at least one closed container is connected to another closed container. It may be configured to be separated from the container by gas. For example, in the case of the embodiment of FIG. 1 described above, as shown in FIG. 9 , each of the lead portions 10 connecting the closed containers 6a, 6b, 6c, and 6d.
In the middle of a, 10b, and 10c, a connecting portion composed of a flange is formed, and the connecting portion is provided with an insulating spacer 28a,
28b, 28c, each closed container 6a, 6b,
The space between 6c and 6d may be divided by gas. According to such a configuration, each closed container 6a, 6b, 6c, 6
a desired insulating medium for components located in d.
For example, insulating oil is contained in the sealed container 6c containing the capacitor 1, insulating gas is contained in the sealed container 6b containing the overvoltage protection device 4, and the semiconductor switch 2 and the reactor 3
Can be filled with a different kind of insulating medium such as air, or the filling pressure can be changed even with the same insulating medium.

[0025]

As described above, the series compensator according to the present invention is electrically connected in parallel with the capacitor as described above.
Power system by controlling the opening and closing of
Can change the degree of reactive reactance compensation,
In other words, it is necessary to optimize the compensation level according to the power flow condition of the system.
Can be stored in a closed container filled with an insulating medium.
Facilitates ground insulation and exposes live parts
It is possible to improve the reliability and reduce the size of the device. Also,
Each component is housed in a sealed container with gas compartments.
For each component in each closed container
Including different types of insulating media with different filling pressures
(Claim 1). In addition, it is electrically
A bypass switch is provided in the row and this bypass switch and
By connecting an open / close switch between capacitors, bypass
Close the switch to bypass the capacitor,
Maintenance inspection of semiconductor switches etc. by opening the switch
Will be separated from the system,
After that, the work can be done safely by grounding the
Claim 2) and furthermore, each constituent element is mutually
Each closed container was stored in a separate closed container.
Can be formed in a size corresponding to each component.
Each closed container can be separated and transported.
In addition to the production of the container, it is easy to carry
3).

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a series compensator according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a series compensator according to another embodiment of the present invention.

FIG. 3 is a schematic configuration diagram of a series compensator according to still another embodiment of the present invention.

FIG. 4 is a schematic configuration diagram of a series compensator according to still another embodiment of the present invention.

FIG. 5 is a schematic configuration diagram of a series compensator according to still another embodiment of the present invention.

FIG. 6 is a schematic configuration diagram of a series compensator according to still another embodiment of the present invention.

FIG. 7 is a front view of a substation using the series compensation device of the present invention.

FIG. 8 is a front view of an intermediate switchyard using the series compensator of the present invention.

FIG. 9 is a schematic configuration diagram of a series compensator according to still another embodiment of the present invention.

[Description of Signs] 1 Capacitor 2 Semiconductor switch 3 Reactor 4 Overvoltage protection device 5 Bypass switch 6, 6a-6d Sealed container 8 Open / close switch 28a, 28b, 28c Insulation spacer

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Tokio Yamagoku 1-1-1, Kokubuncho, Hitachi City, Ibaraki Pref. Hitachi, Ltd. Kokubu Plant (56) References JP-A-53-121137 (JP, A) ) Actually open 60-6020 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H02J 3/00-5/00

Claims (3)

(57) [Claims] 1. A series compensator in which at least a capacitor for compensating reactance of a power system is inserted in series with a power system, wherein a semiconductor switch and a reactor connected in series are connected electrically in parallel with the capacitor,
The capacitor, the semiconductor switch and the reactor are housed in gas-tight sealed containers, respectively,
A series compensator characterized in that an insulating medium is placed in each of the closed containers. 2. A series compensator in which at least a capacitor for compensating reactance of a power system is inserted in series with a power system, wherein a semiconductor switch and a reactor connected in series are connected electrically in parallel with the capacitor, and at least the capacitor is connected. A series compensator characterized in that the compensator is housed in a sealed container containing an insulating medium, and a bypass switch is provided in parallel with the capacitor, and an open / close switch is connected between the bypass switch and the capacitor. 3. A series compensator in which at least a capacitor for compensating reactance of a power system is inserted in series with a power system, wherein a semiconductor switch and a reactor connected in series are connected electrically in parallel with the capacitor,
The capacitor, the semiconductor switch, and the reactor are housed in separate sealed containers, and the sealed containers are communicated with each other through outlets, and furthermore, an insulating medium is provided in each of the sealed containers. A series compensator comprising: