CN105811442A - Method for realizing live-line access of mobile energy storage system to grid-connected 10kV line - Google Patents

Abstract

The present invention relates to the technical field of mobile energy storage systems, in particular to a live access method for grid-connected 10kV lines of mobile energy storage systems. An energy storage system live access device is provided at the access point of the 10kV line energy storage system. The live access device of the energy storage system is connected in series to the 10kV line. The live access device of the energy storage system consists of a vacuum circuit breaker with an isolating switch, an isolating switch, a step-down transformer, a high-voltage switchgear, a voltage transformer, a current transformer and a lightning arrester. The vacuum circuit breaker with isolating switch and the isolating switch are set together, and the step-down transformer, high-voltage switchgear, voltage transformer, current transformer, lightning arrester and energy storage system are combined. The invention effectively realizes the connection and withdrawal of the mobile energy storage system under the condition of no power failure of the 10kV line.

Description

A live access method for grid-connected 10kV lines of mobile energy storage systems

technical field

The invention relates to the technical field of mobile energy storage systems, in particular to a live access method for grid-connected 10kV lines of mobile energy storage systems.

Background technique

In recent years, with the rapid development of my country's economy, higher and higher requirements have been put forward for the power supply capacity and power supply quality of rural power grids and urban distribution networks. Especially during the large-scale return of migrant workers on holidays and irrigation seasons, the load on the rural power grid increases sharply, forming a peak load, resulting in insufficient power supply capacity in some areas and certain periods of time; while in other periods of time, the electricity consumption of the grid is only for general lighting. , The transformer is almost no-load operation, the peak-to-valley gap of the power load is large, the power load rate is low, and the investment efficiency of the power grid is low. In order to improve the power supply capacity of rural power grids and urban power distribution networks during peak loads, and at the same time improve the utilization of power resources and investment benefits, mobile energy storage systems can become one of the key supporting technologies.

The layout of the mobile energy storage system is flexible, and it can be easily transported to the place where it needs to be used. It discharges and runs during the peak load of the rural power grid and the urban distribution network, and charges and runs during the low load, so as to realize the active and reactive power of the rural power grid and the urban power distribution network. Effective support for power.

The patent document of Chinese Patent No. 201220494193.7 discloses an energy storage access system for energy conversion between multiple energy storage batteries and the grid. It is connected to the 10kV rural grid and urban distribution grid system, and the live access of the energy storage system is not considered.

The patent document of Chinese Patent No. 201510002368.6 provides the access method of the energy storage device on the side of the 0.4kV distribution network to achieve high reliability guaranteed power supply and seasonal load application, but the energy storage device is only connected to the 0.4kV distribution network The system does not consider access to the 10kV rural grid and urban distribution grid system, nor does it consider the live access of energy storage devices.

The patent document of Chinese Patent No. 201410253870.X discloses a box-type energy storage substation structure, including a high-voltage incoming cabinet connected to the high-voltage power grid, and the high-voltage current output by the high-voltage incoming cabinet is transmitted to the low-voltage power distribution cabinet through a transformer and a metering cabinet , There is an energy storage room between the metering cabinet and the low-voltage power distribution cabinet, but this invention does not consider that the energy storage device is connected to the 10kV rural power grid and urban power distribution grid system.

Contents of the invention

In view of the above problems, the present invention provides a live access method for a mobile energy storage system connected to a grid-connected 10kV line, so as to realize the plug-and-play of the mobile energy storage system without power failure of the 10kV line.

In order to achieve the above object, the technical scheme adopted in the present invention is as follows:

A live access method for a grid-connected 10kV line of a mobile energy storage system. An energy storage system live access device is installed at the access point of the 10kV line energy storage system, and the energy storage system live access device is connected in series to the 10kV line. The live connection device of the energy storage system is composed of a vacuum circuit breaker with an isolating switch, an isolating switch, a step-down transformer, a high-voltage switchgear, a voltage transformer, a current transformer, and a lightning arrester, etc. The vacuum circuit breaker with an isolating switch and the isolating switch Cooperating with the setting, the step-down transformer, high voltage switch cabinet, voltage transformer, current transformer, lightning arrester and energy storage system are set in combination.

Further, the vacuum circuit breaker with isolating switch includes a first vacuum circuit breaker and a second vacuum circuit breaker, the first vacuum circuit breaker is connected in series on the bus bar side and the negative line side of the 10kV line, and the second vacuum circuit breaker is connected in series on the On the busbar side of the 10kV line, the isolating switch is connected in series on the negative line side of the 10kV line. With such a structural setting, the connection and withdrawal of the mobile energy storage system under the condition of no power failure of the 10kV line can be realized through the combined action of the circuit breaker and the isolation switch.

Further, the second vacuum circuit breaker is connected to the lightning arrester and the current transformer, the isolating switch is connected to the voltage transformer, the current transformer and the voltage transformer are respectively connected to the high-voltage switchgear, and the high-voltage switchgear is connected to the step-down transformer , the buck-boost transformer is connected to the energy storage system. With such a structural setting, the live access and exit of grid-connected 10kV lines can be realized.

Further, the energy storage system is composed of an energy storage battery, an energy storage bidirectional converter, and an energy storage monitoring device. Due to the flexible layout of the energy storage system, it can be easily transported to the access point of the energy storage system. The energy storage batteries include but are not limited to lead-acid batteries, lithium batteries, flow batteries and supercapacitors.

Beneficial effects of the present invention:

The invention realizes the plug-and-play of the mobile energy storage system in the case of no power failure of the 10kV line by setting the live access device of the energy storage system at the access point of the energy storage system, avoids the economic loss caused by the power failure of the line, and fully utilizes the energy storage system. The mobile energy storage system has the advantages of adjustable power capacity, system efficiency and flexible layout, which solves the problem of peak load and seasonal load difference at the end of the rural grid and urban distribution network, and improves the power supply capacity of the rural grid and urban distribution network and reliability.

Description of drawings

Fig. 1 is a schematic diagram of the charged access device of the present invention;

Fig. 2 is a schematic diagram of the energy storage system of the present invention.

QF1, the first vacuum circuit breaker; QF2, the second vacuum circuit breaker; QS1, isolating switch; F1, arrester; PT, voltage transformer; CT, current transformer.

detailed description

The technical solutions of the present invention will be described below in conjunction with the accompanying drawings and embodiments.

As shown in Figure 1, a live access method of a mobile energy storage system connected to the grid 10kV line according to the present invention is provided with an energy storage system live access device at the access point of the 10kV line energy storage system, and the energy storage system is charged The access device is connected in series to the 10kV line. The live access device of the energy storage system consists of a vacuum circuit breaker with an isolating switch, an isolating switch QS1, a step-down transformer, a high-voltage switchgear, a voltage transformer PT, a current transformer CT and a lightning arrester. F1, etc., the vacuum circuit breaker with isolating switch and isolating switch QS1 are set in cooperation, and the step-down transformer, high-voltage switchgear, voltage transformer PT, current transformer CT, lightning arrester F1 and energy storage system are set in combination.

The above constitutes the basic structure of the present invention, wherein the step-down transformer is used for the conversion of the 10kV voltage of the power grid and the output 380V voltage of the energy storage bidirectional converter, the high-voltage switchgear realizes the energy storage system is connected to the 10kV high-voltage line, the voltage transformer PT and the current mutual inductance The CT measures the voltage and current where the energy storage system is connected to the 10kV line, and configures a lightning arrester F1 on the input side of the mobile energy storage system to prevent the energy storage system from being damaged by lightning.

More specifically, the vacuum circuit breaker with isolating switch includes a first vacuum circuit breaker QF1 and a second vacuum circuit breaker QF2. The circuit breaker QF2 is connected in series on the bus side of the 10kV line, and the isolating switch QS1 is connected in series on the negative line side of the 10kV line. With such a structural setting, the connection and withdrawal of the mobile energy storage system under the condition of no power failure of the 10kV line can be realized through the combined action of the circuit breaker and the isolation switch.

More specifically, the second vacuum circuit breaker QF2 is connected to the lightning arrester F1 and the current transformer CT, the isolating switch QS1 is connected to the voltage transformer PT, and the current transformer CT and the voltage transformer PT are respectively connected to the high voltage switchgear, so The high-voltage switchgear is connected to a step-down transformer, and the step-down transformer is connected to an energy storage system. With such a structural setting, the live access and exit of grid-connected 10kV lines can be realized.

When the mobile energy storage system is connected to the 10kV line, the circuit breaker QF1 is in the closing position, and the circuit breaker QF2 and the isolation switch QS1 are in the off position. According to the phase sequence of the 10kV line, connect one side of the mobile energy storage system to the circuit breaker QF2 and the other side to the isolating switch QS1, close the isolating switch QS1 and the circuit breaker QF2 in turn, and then disconnect the circuit breaker QF1 to realize the mobile energy storage system. The energy storage system is connected to the 10kV line without power failure.

When the mobile energy storage system exits the 10kV line, the circuit breaker QF1 is in the off position, and the circuit breaker QF2 and the isolation switch QS1 are in the close position. After the energy storage system stops running, close the circuit breaker QF1, turn off the circuit breaker QF2 and the isolating switch QS1 in turn, and disconnect the connecting cable between the mobile energy storage system and the circuit breaker QF2 and isolating switch QS1 to realize the mobile energy storage The system exits the 10kV line without power failure.

More specifically, as shown in FIG. 2 , the energy storage system in the present invention consists of an energy storage battery, an energy storage bidirectional converter, and an energy storage monitoring device. The energy storage batteries include but are not limited to lead-acid batteries, lithium batteries, liquid flow batteries and supercapacitors. On the one hand, the energy storage monitoring device monitors the operating status of the energy storage battery and the energy storage bidirectional converter to ensure the safe and reliable operation of the energy storage system; charging and discharging operation.

The mobile energy storage system has the function of local charge and discharge control, and also has the function of remote control. According to the power curve of the power grid dispatching department, the energy storage system is controlled to discharge during the peak load of the rural grid and the urban distribution network, and to charge during the low load. Realize the "peak shifting and valley filling" of the load.

The above are preferred embodiments of the present invention, and those skilled in the art to which the present invention pertains can also make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments described above, and any obvious improvement, replacement or modification made by those skilled in the art on the basis of the present invention falls within the protection scope of the present invention.

Claims (4)

1. the charged cut-in method of a Mobile energy storage system grid connection 10kV circuit, it is characterized in that: 10kV circuit energy-storage system access point is provided with the charged access device of energy-storage system, the charged access device series connection of described energy-storage system accesses in 10kV circuit, the charged access device of described energy-storage system is by the vacuum circuit breaker with isolation switch, isolation switch, step transformer, high-tension switch cabinet, voltage transformer, current transformer and spark gap composition, the described vacuum circuit breaker with isolation switch is equipped with isolation switch, described step transformer, high-tension switch cabinet, voltage transformer, current transformer, spark gap is arranged with energy-storage system combination.

2. the charged cut-in method of a kind of Mobile energy storage system grid connection 10kV circuit according to claim 1, it is characterized in that: the described vacuum circuit breaker with isolation switch includes the first vacuum circuit breaker and the second vacuum circuit breaker, described first vacuum circuit breaker is connected on bus bar side and the negative wire side of 10kV circuit, described second vacuum circuit breaker is connected on 10kV line bus side, and described isolation switch is connected on 10kV circuit negative wire side.

3. the charged cut-in method of a kind of Mobile energy storage system grid connection 10kV circuit according to claim 2, it is characterized in that: described second vacuum circuit breaker is connected to spark gap and current transformer, the described pass that keeps apart is connected to voltage transformer, described current transformer and voltage transformer are connected to high-tension switch cabinet, described high-tension switch cabinet is connected to step transformer, and described step transformer is connected to energy-storage system.

4. the charged cut-in method of a kind of Mobile energy storage system grid connection 10kV circuit according to claim 1, it is characterised in that: described energy-storage system is made up of energy-storage battery, energy storage two way convertor, energy storage supervising device.