CN103855618A - 10kV switching station - Google Patents

Abstract

A 10kV switch station, the switch station includes a first section of busbar and a second section of busbar connected in series through a segmented switch cabinet, each section of busbar is respectively connected to one incoming line and five outgoing lines, and the outgoing lines are also connected to the substation transformer . The switch station incoming line of the present invention is equipped with optical fiber longitudinal differential protection, which fully exerts the function of the switch station as a substation 10kV bus extension, and provides sufficient power supply for adding a cable ring network in the core area.

Description

10kV switch station

technical field

The invention relates to a 10 kV switch station.

Background technique

Shanghai is the largest city in my country, one of the four central municipalities, and the center of my country's economy, finance, trade and shipping. In 2012, Shanghai's GDP reached 2.01 trillion yuan, ranking 11th in the world. Both the per capita GDP and per capita disposable income rank first in all provinces, autonomous regions and municipalities directly under the Central Government. Shanghai is currently in a critical period of "industrial transformation" and is striving to build "four centers" - an international economic center, an international financial center, an international trade center, and an international shipping center. This puts forward higher requirements for the city's power supply capacity. .

Shanghai Pudong New Area covers an area of 1210.41 square kilometers. Since the Party Central Committee and the State Council decided to "Pudong Development" in the 1990s, it has experienced more than 20 years of development. It has built Jinqiao, Zhangjiang National Development Zone, Waigaoqiao Free Trade Zone, Lujiazui Finance and Trade Zone, etc. focus area. On July 3, 2013, the "China (Shanghai) Pilot Free Trade Zone" was approved and settled in 28 square kilometers along the coast of Pudong New Area, marking a new starting point for Shanghai's development. As the largest and most dynamic district and county in the city, Pudong New Area leads the city in many aspects including economic development and industrial transformation.

The construction scope of the distribution network in the Pudong core area is the core area along the Huangpu River in Pudong, west to the Huangpu River, north to the Huangpu River, east to Pudong South Road, and south to Yaohua Road, covering an area of about 10 square kilometers. The rapid growth of power load in this core area and the natural extension of distribution network lines inevitably lead to problems such as blurred boundaries, crossed lines, and circuitous power supply, which affect the reliability of power supply and the leanness of line loss.

On the basis of comprehensive evaluation of distribution network operation level and power supply capacity, by analyzing the problems existing in the current distribution network, it is concluded that the 10kV distribution network is an absolute factor affecting the power supply reliability of Pudong power grid, and the planned power outage is the most important factor affecting the Pudong power grid. The main factor of power supply reliability. To improve the reliability of power supply, it is the fundamental way to strengthen the 10kV medium-voltage distribution network and reduce the impact of planned power outages, which requires the distribution network to have flexible load transfer capabilities. Looking at the planning and development of urban power grids in advanced international regions, similar conclusions can be drawn. A solid distribution network grid structure and flexible load transfer capabilities are the foundation of a modern distribution network.

The switch station is used as the 10kV main power supply in the grid frame of the distribution network. The switch station is a type of indoor distribution station. The incoming line of the switch station is not equipped with a relay protection device, and the outgoing line is equipped with a relay protection, using a circuit breaker. And distribution transformers can be configured as needed. The incoming line of the switch station currently in use is not equipped with optical fiber longitudinal differential protection, which has poor reliability.

Contents of the invention

The invention provides a 10kV switch station, the incoming line is equipped with optical fiber vertical differential protection, which fully exerts the function of the switch station as an extension of the 10kV busbar of the substation, and provides sufficient power supply for the addition of a cable ring network in the core area.

In order to achieve the above object, the present invention provides a 10 kV switch station, which includes a first section of busbar and a second section of busbar connected in series through sectional switch cabinets, and each section of busbar is connected with one incoming line and five outgoing lines respectively. The outgoing line is also connected to the station transformer.

The incoming line is connected to the substation, and the incoming line includes a current transformer and a circuit breaker connected in series. The current transformer detects the current of the incoming line and collects the current for optical fiber longitudinal differential protection. If the collected current value is greater than the set value, Then the protection will act and the circuit breaker will be disconnected.

The incoming line also includes a charging indicator and a grounding switch. After the charging indicator and the grounding switch are connected in parallel, the current transformer is connected in series. When the incoming line has power, the charging indicator will display red. When the grounding switch is grounded.

The outgoing line includes a circuit breaker and a current transformer connected in series. The current transformer detects the current of the outgoing line and collects the current for the optical fiber longitudinal difference protection. If the value of the collected current is greater than the set value, the protection will operate and the circuit breaker will be disconnected. .

The outgoing line also includes a charging indicator and a grounding knife. After the liveness indicator and the grounding knife are connected in parallel, the current transformer is connected in series. The switch is grounded.

The sectional switchgear includes circuit breakers and current transformers connected in series. The sectional switchgear plays the role of automatic switching, and the circuit breaker is disconnected during normal operation. As a result, a section of the bus is de-energized. After the fault incoming switch is disconnected, the circuit breaker is closed to supply power to the de-energized bus.

The station substation includes switch blades connected in series, fuses, station transformer transformers and grounding switch blades. The switch blades are grounded when the station substation is overhauled and disconnected at ordinary times. The fuse prevents the station transformer from overcurrent. The station transformer transformer provides outgoing power, and the grounding switch is grounded when the station transformer is overhauled.

In the switchyard, each section of the busbar is also connected to a surge arrester and voltage transformer compartment, and the arrester and potential transformer compartment include a three-phase voltage transformer, and a surge arrester connected in parallel with the three-phase voltage transformer, three-phase The voltage transformer collects the bus voltage for relay protection, and the lightning arrester plays the role of bus lightning protection.

The invention is equipped with optical fiber vertical differential protection for the incoming line, fully exerts the function of the switch station as an extension of the 10kV busbar of the substation, and provides sufficient power supply for the addition of a cable ring network in the core area.

Description of drawings

Fig. 1 is a circuit diagram of the present invention.

Detailed ways

Hereinafter, a preferred embodiment of the present invention will be described in detail according to FIG. 1 .

As shown in Fig. 1, the present invention provides a kind of 10kV switchyard, and this switchyard comprises the first section busbar 201 and the second section busbar 202 connected in series by section switch cabinet 5, and each section busbar is respectively connected with a return line 1 And five times outgoing line 4, described outgoing line 4 is also connected to station with change 6.

The incoming line 1 is connected to the substation, and the incoming line 1 includes a current transformer 101 and a circuit breaker 102 connected in series. The current transformer 101 detects the amount of current in the incoming line, and collects the amount of current for optical fiber longitudinal differential protection. If the collected current amount If the value is greater than the set value, the protection will act and the circuit breaker 102 will be disconnected.

The incoming line 1 also includes a charging indicator 103 and a grounding switch 104. After the charging indicator 103 and the grounding switch 104 are connected in parallel, the current transformer 101 is connected in series. When the incoming line has power, the charging indicator 103 displays Red, the grounding switch 104 is grounded during line maintenance.

The outgoing line 4 includes a circuit breaker 401 and a current transformer 402 connected in series. The current transformer 402 detects the current of the outgoing line and collects the current for the optical fiber longitudinal difference protection. If the collected current value is greater than the set value, the protection will operate. Open circuit breaker 401 .

The outgoing line 4 also includes a charging indicator 403 and a grounding switch 404. After the charging indicator 403 and the grounding switch 404 are connected in parallel, the current transformer 402 is connected in series. When the outgoing line has power, the charging indicator 403 displays red. The grounding switch 404 is grounded during line maintenance.

The sectioned switchgear 5 includes a circuit breaker 501 and a current transformer 502 connected in series. The sectioned switchgear mainly plays the role of self-switching, and the circuit breaker 501 is disconnected during normal operation. The power failure of one incoming line leads to the power loss of a bus bar. After the faulty incoming line switch is turned off, the circuit breaker 501 is closed to supply power to the bus bar that has lost power.

The station transformer 6 includes a series switch switch 601, a fuse 602, a station transformer 603 and a ground switch 604. The switch switch 601 is grounded when the station transformer 6 is overhauled, and is usually disconnected. 602 prevents station transformer from overcurrent, station transformer transformer 603 provides outgoing power, and ground switch 604 is grounded during station transformer maintenance.

In the switchyard, each section of the busbar is also connected to a lightning arrester and a voltage transformer compartment 3, and the lightning arrester and voltage transformer compartment 3 include a three-phase voltage transformer 301, and a three-phase voltage transformer 301 connected in parallel lightning arrester 302 . The three-phase voltage transformer 301 collects bus voltage for relay protection, and the lightning arrester 302 acts as bus lightning protection.

The scale of the incoming and outgoing lines of the switch station is selected as two in and ten out, and each section of incoming line has optical fiber longitudinal difference protection: the current phase and magnitude are detected on the incoming line side of the switch station and the corresponding outgoing line side of the superior station, and the current flow of the superior outgoing line For the incoming line transmitted to the switching station through optical fiber, if the outgoing current of the upper level is inconsistent with the incoming line current of the station (greater than the protection setting value), the line is considered to be faulty, and the protection action disconnects the incoming line switch of the station and the corresponding outgoing line switch of the upper level. The switch station adopts single busbar section, and the cross-section of each cable for the incoming line and tie line is 3×400mm ² , and the outgoing cable can be selected according to the load condition; the switch station is sent by two power supply lines from different substations, and the maximum load of each circuit is The rate is 50%; the capacity of the transformer in the distribution transformer module in the switch station depends on the low-voltage load in the surrounding area. This station is a 10kV distribution station, which is connected to two busbars. Each section of bus has one incoming line and five outgoing lines, and one station uses a transformer. There is a section switch between the first and second busbars. Each outgoing line can be connected to a lower-level substation or box transformer and then supply power to end users.

The planning of the distribution network in the core area takes the divided grid as the planning unit. Firstly, based on the load size, a certain number of switch stations are arranged in each grid as the 10kV main power supply in the grid. The incoming lines of the switch station come from different 110 (35) kV substations, which are mainly laid along the municipally planned roads; the 10kV and low-voltage outgoing lines are laid along the internal roads of the community, and try not to cross or cross the municipally planned roads as much as possible, so that a grid is formed. Basic, several relatively independent sheet-like partitioned distribution networks with non-crossing and overlapping power supply scopes.

The invention is equipped with optical fiber vertical differential protection for the incoming line, fully exerts the function of the switch station as an extension of the 10kV busbar of the substation, and provides sufficient power supply for the addition of a cable ring network in the core area.

Although the content of the present invention has been described in detail through the above preferred embodiments, it should be understood that the above description should not be considered as limiting the present invention. Various modifications and alterations to the present invention will become apparent to those skilled in the art upon reading the above disclosure. Therefore, the protection scope of the present invention should be defined by the appended claims.

Claims (8)

1. A 10 kV switch station, characterized in that the switch station includes a first section of busbar (201) and a second section of busbar (202) connected in series through a section switch cabinet (5), and each section of busbar is connected once The incoming line (1) and the five-circuit outgoing line (4), the outgoing line (4) is also connected to the station transformer (6). 2. The 10 kV switchyard according to claim 1, characterized in that, the incoming line (1) is connected to a substation, and the incoming line (1) includes a series connected current transformer (101) and circuit breaker (102) , the current transformer (101) detects the current of the incoming line, and collects the current for the optical fiber differential protection. If the collected current value is greater than the set value, the protection will operate and the circuit breaker (102) will be disconnected. 3. The 10 kV switching station according to claim 2, characterized in that, the incoming line (1) also includes a charging indicator (103) and a grounding switch (104), the charging indicator (103) and After the grounding switch (104) is connected in parallel, the current transformer (101) is connected in series. When the incoming line has electricity, the charging indicator (103) displays red, and the grounding switch (104) is grounded when the line is overhauled. 4. The 10 kV switchyard according to claim 1, characterized in that, the outgoing line (4) includes a circuit breaker (401) and a current transformer (402) connected in series, and the current transformer (402) detects the The amount of current is the amount of current collected by the optical fiber longitudinal differential protection. If the value of the collected current is greater than the set value, the protection will operate and the circuit breaker will be disconnected (401). 5. The 10 kV switchyard according to claim 4, characterized in that, the outgoing line (4) also includes a charging indicator (403) and a grounding switch (404), and the charging indicator (403) and the grounding After the switch knife (404) is connected in parallel, the current transformer (402) is connected in series. When the outgoing line has electricity, the charging indicator (403) displays red, and the grounding switch (404) is grounded when the circuit is overhauled. 6. The 10 kV switch station according to claim 1, characterized in that, the section switch cabinet (5) includes circuit breakers (501) and current transformers (502) connected in series, and the section switch cabinet is prepared Self-transfer function, the circuit breaker (501) is disconnected during normal operation, and when the backup self-transition protection is enabled, if one of the incoming lines loses power and causes a section of the bus to lose power, after the faulty incoming line switch is turned off, the circuit breaker (501) Close to supply power to the de-energized bus. 7. The 10 kV switch station according to claim 1, characterized in that, the station transformer (6) includes a switch knife (601), a fuse (602), a station transformer (603) and The ground switch (604), the switch knife (601) is grounded when the station transformer (6) is overhauled, and it is usually disconnected. The fuse (602) prevents the station transformer from overcurrent, and the station transformer (603) provides Outgoing power supply, the grounding switch (604) is grounded when the station substation is overhauled. 8. The 10 kV switchyard according to claim 1, characterized in that, in the switchyard, each section of the busbar is also connected to a lightning arrester and a voltage transformer compartment (3), and the lightning arrester and voltage transformer compartment (3) It includes a three-phase voltage transformer (301) and a lightning arrester (302) connected in parallel with the three-phase voltage transformer (301). The three-phase voltage transformer (301) collects the bus voltage for relay protection, and the lightning arrester ( 302) play the role of busbar lightning protection.

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