A 35kV line spare power automatic switching method

Abstract

The present application relates to a kind of 35kV line spare power automatic switching methods, comprising the following steps: step (1), construct a double-end power supply network system, it includes two 220kV substations, and is defined as substation A and substation B;Between the low voltage side 35kV outgoing terminal of substation A and the low voltage side 35kV outgoing terminal of substation B, a group of 35kV substations is connected by 35kV tie line, 35kV tie line is located at the low voltage side 35kV outgoing terminal of substation A, the low voltage side 35kV outgoing terminal of substation B, the two sides of each 35kV substation are provided with tie switch, and one of them is set as open loop point, defined as spare switch.The present application can effectively solve the problem that in the double-end power supply system between the existing two 220kV substations, during fault process, cannot be transferred by spare power automatic switching to realize supply.

Description

TECHNICAL FIELD

[0001] The application relates to a 35kV line spare power automatic switching method. BACKGROUND

[0002] Most of the power distribution networks in China are in the radial single-loop connection mode. When a line fault occurs, the power supply needs to be cut off, which will cause a short-time power failure at the user end of the branch, thereby destroying the stability of the system power supply and failing to meet the requirements of users on power supply continuity.

[0003] After the local spare power automatic switching is installed, only the circuit breakers of the lines that are mutually reserved in the station are controlled. When the substation is powered by a single line and the switches on the opposite sides of the remaining reserved lines are cold standby, even if the local spare power automatic switching is actuated, the substation is still in a power failure state, and manual operation is required to restore the power supply.

[0004] Therefore, a method for realizing the spare power automatic switching during a fault in a double-end power supply system between two 220kV substations needs to be designed. SUMMARY

[0005] (I) Technical problems solved

[0006] In view of the defects of the prior art, the application provides a 35kV line spare power automatic switching method, which solves the problem that in the double-end power supply system between two 220kV substations, the spare power automatic switching cannot be realized to realize the power supply switching during a fault.

[0007] (II) Technical scheme

[0008] To achieve the above object, the application provides the following technical scheme: a 35kV line spare power automatic switching method, comprising the following steps:

[0009] Step (1), a double-end power supply network system is constructed, which comprises two 220kV substations and is defined as substation A and substation B; a group of 35kV substations is connected between the 35kV outgoing line side of the low-voltage side of the substation A and the 35kV outgoing line side of the low-voltage side of the substation B through a 35kV tie line; the 35kV tie line is located on the two sides of the substation A low-voltage side 35kV outgoing line side, the substation B low-voltage side 35kV outgoing line side and each 35kV substation, and a tie switch is arranged on each side, and one of the tie switches is set as an open-loop point and is defined as a standby switch;

[0010] Step (2), define the power supply line from substation A to the spare switch as power supply line A, and the power supply line from substation B to the spare switch as power supply line B; each 35kV substation is provided with a spare power automatic device for controlling the tie switch and the spare switch; and a total control device is arranged in substation A or substation B; the spare power automatic device and the total control device are connected through optical fiber for signal transmission; a spare power automatic control system is formed through the total control device, the spare power automatic device and the optical fiber;

[0011] Step (3), each spare power automatic device monitors the voltage and current of the corresponding 35kV substation in real time, and can control the working state of the tie switch or the spare switch on both sides of the corresponding 35kV substation, and sends signals to the total control device in real time;

[0012] Step (4), when the total control device receives the loss of voltage signal of the 35kV substation transmitted by the spare power automatic device, it is determined that a fault occurs; when only one loss of voltage signal of the 35kV substation is received, a control signal is transmitted to the spare power automatic device of the loss of voltage 35kV substation, the tie switch near the 220kV transformer of the loss of voltage 35kV substation is tripped, and the trip signal is transmitted back to the total control device; after receiving the trip signal, the total control device sends a control signal to the spare power automatic device of the 35kV transformer where the spare switch is located, and the spare power automatic device of the 35kV transformer where the spare switch is located controls the spare switch to close, thus completing the spare power automatic switching; when multiple loss of voltage signals of the 35kV substation are received, step (5) is performed;

[0013] Step (5), when multiple loss of voltage signals of the 35kV substation are received, the total control device first determines whether they are on the power supply line A or the power supply line B; if they are on the same power supply line, a control signal is sent to the spare power automatic device of the most upstream loss of voltage 35kV substation according to the current flow direction, the tie switch near the 220kV transformer of the loss of voltage 35kV substation is tripped, and the trip signal is transmitted back to the total control device; after receiving the trip signal, the total control device sends a control signal to the spare power automatic device of the 35kV transformer where the spare switch is located, and the spare power automatic device of the 35kV transformer where the spare switch is located controls the spare switch to close, thus completing the spare power automatic switching; if they are not on the same power supply line, step (6) is performed;

[0014] Step (6), when multiple loss of voltage signals of the 35kV substation are received and they are not on the same power supply line, the total control device does not send any spare power automatic device of the 35kV substation a switching signal, and an alarm signal is sent.

[0015] (Three) beneficial effects

[0016] Compared with existing technologies, by setting up a main control device and backup automatic transfer devices in 35kV substations, and connecting the main control device and each backup automatic transfer device through fiber optic signals, the operating status of each backup automatic transfer device can be controlled by the main control device, thereby controlling the switching of the open and closed positions of the tie switches and standby switches of each 35kV substation, and finally realizing the transfer of power supply in the event of a fault.

[0017] This invention proposes a backup automatic transfer control system that consists of a central control device and various backup automatic transfer devices connected by optical fibers.

[0018] The backup switching mechanism of this invention collects signals from each switching device through a central control device and performs overall control of each backup automatic switching device, without involving other parameters such as protection settings, making the method simple. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the present invention. The number of 35kV substations shown in the diagram is only an exemplary number and can be increased or decreased according to actual needs. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] like Figure 1 The method for automatic transfer switching of a 35kV line shown includes the following steps:

[0022] Step (1): Construct a dual-end power supply network system, which includes two 220kV substations, and is defined as substation A and substation B. The connection between the 35kV outgoing line terminal of the low-voltage side of substation A and the 35kV outgoing line terminal of the low-voltage side of substation B is a set of 35kV substations connected by a 35kV tie line. The 35kV tie line is located on the 35kV outgoing line side of the low-voltage side of substation A and the 35kV outgoing line side of the low-voltage side of substation B. Tie switches are set on both sides of each 35kV substation, and one of the tie switches is set as the open loop point and defined as the standby switch.

[0023] Step (2), define the power supply line from substation A to the spare switch as power supply line A, and the power supply line from substation B to the spare switch as power supply line B; each 35kV substation is provided with a spare power automatic device for controlling the tie switch and the spare switch; and a total control device is arranged in substation A or substation B; the spare power automatic devices and the total control device are connected by optical fibers for signal transmission; a spare power automatic control system is formed by the total control device, the spare power automatic devices and the optical fibers;

[0024] Step (3), each spare power automatic device monitors the voltage and current of the corresponding 35kV substation in real time, and can control the working state of the tie switch or the spare switch on both sides of the corresponding 35kV substation, and sends signals to the total control device in real time;

[0025] Step (4), when the total control device receives the loss of voltage signal of the 35kV substation transmitted by the spare power automatic device, it is determined that a fault occurs; when only one loss of voltage signal of the 35kV substation is received, a control signal is transmitted to the spare power automatic device of the loss of voltage 35kV substation, the tie switch near the 220kV transformer of the loss of voltage 35kV substation is tripped by the spare power automatic device, and the trip signal is transmitted back to the total control device; after receiving the trip signal, the total control device sends a control signal to the spare power automatic device of the 35kV transformer where the spare switch is located, and the spare power automatic device of the 35kV transformer where the spare switch is located controls the spare switch to close, thus completing the spare power automatic switching; when multiple loss of voltage signals of the 35kV substations are received, go to step (5);

[0026] Step (5), when multiple loss of voltage signals of the 35kV substations are received, the total control device first determines whether they are all in the power supply line A or the power supply line B; if they are all in the same power supply line, a control signal is sent to the spare power automatic device of the most upstream loss of voltage 35kV substation according to the current flow direction, the tie switch near the 220kV transformer of the loss of voltage 35kV substation is tripped by the spare power automatic device, and the trip signal is transmitted back to the total control device; after receiving the trip signal, the total control device sends a control signal to the spare power automatic device of the 35kV transformer where the spare switch is located, and the spare power automatic device of the 35kV transformer where the spare switch is located controls the spare switch to close, thus completing the spare power automatic switching; if they are not in the same power supply line, go to step (6);

[0027] Step (6), when multiple loss of voltage signals of the 35kV substations are received, and they are not in the same power supply line, the total control device does not send any spare power automatic device of the 35kV substation a switching signal, and an alarm signal is sent.

[0028] It is to be understood that the terminology "including", "comprising", or any other variation thereof, is intended to cover a non-exclusive inclusion such that process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by "comprises a... " does not, without more constraints, exclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.

[0029] While embodiments of the application have been shown and described, it is to be understood that the application is not limited to the details of the embodiments described, since the scope of the application is defined with respect to the appended claims.

Claims

1. A 35kV line spare power automatic switching method, characterized in that: Comprising the following steps: Step (1), constructing a double-ended power supply grid system, which includes two 220kV substations, and is defined as substation A and substation B; a group of 35kV substations is connected between the 35kV outgoing line of the low-voltage side of substation A and the 35kV outgoing line of the low-voltage side of substation B through a 35kV tie line; the 35kV tie line is located at the 35kV outgoing line side of the low-voltage side of substation A, the 35kV outgoing line side of the low-voltage side of substation B, and the two sides of each 35kV substation are provided with tie switches, and one of the tie switches is set as an open-loop point, defined as a backup switch; Step (2), defining the power supply line from substation A to the backup switch as power supply line A, and defining the power supply line from substation B to the backup switch as power supply line B; each 35kV substation is provided with a backup automatic switching device for controlling the tie switch and the backup switch; and a total control device is arranged in substation A or substation B, and each backup automatic switching device and the total control device are connected by optical fiber for signal transmission; a backup automatic switching control system is formed by the total control device, each backup automatic switching device, and the optical fiber; Step (3), each backup automatic switching device monitors the voltage and current of the corresponding 35kV substation in real time, and can control the working state of the tie switch or the backup switch on the two sides of the corresponding 35kV substation, and sends signals to the total control device in real time; Step (4), when the total control device receives the loss-of-voltage signal of the 35kV substation transmitted by the backup automatic switching device, it is determined that a fault has occurred; when only one loss-of-voltage signal of the 35kV substation is received, a control signal is transmitted to the backup automatic switching device of the loss-of-voltage 35kV substation, the tie switch on the side close to the 220kV transformer of the loss-of-voltage 35kV substation is tripped by the backup automatic switching device, and the trip signal is transmitted back to the total control device; after receiving the trip signal, the total control device sends a control signal to the backup automatic switching device of the 35kV transformer where the backup switch is located, the backup automatic switching device of the 35kV transformer where the backup switch is located controls the backup switch to close, and the backup automatic switching is completed; when multiple loss-of-voltage signals of 35kV substations are received, step (5) is performed; Step (5), when multiple loss-of-voltage signals of 35kV substations are received, the total control device first determines whether they are all in power supply line A or power supply line B; if they are in the same power supply line, a control signal is sent to the backup automatic switching device of the most upstream loss-of-voltage 35kV substation according to the current flow direction, the tie switch on the side close to the 220kV transformer of the loss-of-voltage 35kV substation is tripped by the backup automatic switching device, and the trip signal is transmitted back to the total control device; after receiving the trip signal, the total control device sends a control signal to the backup automatic switching device of the 35kV transformer where the backup switch is located, the backup automatic switching device of the 35kV transformer where the backup switch is located controls the backup switch to close, and the backup automatic switching is completed; if they are not in the same power supply line, step (6) is performed; Step (6), when multiple loss-of-voltage signals of 35kV substations are received and they are not in the same power supply line, the total control device does not send any backup automatic switching device signal to any 35kV substation, and an alarm signal is sent.

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