CN101958567A - Electric vehicle charging station system with energy storage device and control method thereof - Google Patents

Abstract

The invention discloses an electromobile charging station system with an energy storage equipment, which comprises an alternate current supply power grid, monitoring equipment, charging equipment and energy storage equipment, wherein the alternate current supply power grid is accessed into the electromobile charging station system though a high-voltage relay protection cabinet, a three-phase transformer and a low-voltage relay protection cabinet; the monitoring equipment completes monitoring and control for the electromobile charging station system and guides the operation of the whole electromobile charging station system; the energy storage equipment contains a plurality of energy storage equipment groups, and each energy storage equipment group comprises a plurality of switch controllers and energy storing devices. The electromobile charging station system can effectively alleviate impact on the power grid, which is caused by quick charging, slow power grid pressure and provide charging service for different types electromobiles manufactured by different manufacturers. The electromobile charging station system has the advantages of convenient charging service, simple and flexible operation and convenient maintenance.

Description

Electric vehicle charging station system with energy storage device and control method thereof

technical field

The invention belongs to the technical field of electric vehicles and power systems, and in particular relates to an electric vehicle charging station with an energy storage device and a configuration and operation method thereof.

Background technique

With the increasingly serious energy crisis and the gradual enhancement of people's awareness of environmental protection, clean energy vehicles have been widely developed and popularized, among which the development technology of electric vehicles is the most mature. The charging forms of electric vehicles can be mainly divided into two types: battery pack replacement and charging station/pile charging.

Due to the different power requirements and sizes of vehicles, limited vehicle space and great differences in layout, it is difficult to standardize the battery pack capacity, battery pack configuration and size required by different vehicles, and the charging method of replacing the battery pack is generally applicable. A specific type of vehicle power supply, such as a large passenger car or transport vehicle with sufficient space using a modular standard battery pack; or a charging station that specifically designates battery pack replacement for several types of electric vehicles of a certain company. This method has a small scope of application and poor versatility, and cannot meet the charging needs of various electric vehicles.

The vehicle charging station/pile charging method is almost applicable to the charging of all electric vehicles. At present, there are two working modes for charging: normal charging mode (generally 6-8 hours for full charging), the most common one is for household electric vehicles to charge while parking in the parking lot; fast charging, electric vehicles are fully charged for 80 minutes in 15-20 minutes at the charging station. % more than electric energy. However, with normal rate charging, the charging speed of the vehicle is too slow to meet the timeliness requirements of commercial vehicles and long-distance running vehicles. Compared with the normal rate charging method, the fast charging technology can meet the timeliness requirements of vehicles, but the charging current of each vehicle is dozens of times higher than the normal charging current, which will bring current shocks to the power grid. When a large number of electric vehicles are concentrated in charging When fast charging at the same time, the energy required in a short period of time is extremely large, which will generate a huge inrush current, which will threaten the stable and safe operation of the power grid, and even damage the power grid equipment such as lines and transformers. Therefore, the relevant substations and lines must be Capacity expansion is carried out, but the average utilization rate of the expanded substation and line capacity is very low, which is not economically cost-effective. In addition, fast charging at charging stations is generally used during the daytime during peak power consumption, which will not only increase the burden on the power grid, but also increase the cost of power consumption.

How to solve the problem of charging electric vehicles with charging stations economically, efficiently, safely and reliably is of great significance to the popularization and application of electric vehicles and to ensure the economical, safe and efficient operation of the power grid. Therefore, it is necessary to develop a charging station solution to effectively solve a series of technical and economic problems such as the excessive charging impact current of the charging station on the grid, the excessive capacity of the substation and the line, and the low utilization rate.

Contents of the invention

Purpose of the invention: In view of the deficiencies in the prior art, the purpose of the present invention is to provide an electric vehicle charging station system with an energy storage device, so that it can overcome the rapid charging of electric vehicles while meeting the needs of fast charging of electric vehicles. The power impact caused by the power grid will greatly reduce the substation capacity and line capacity required by the electric vehicle charging station, and ensure the safe and stable operation of the power grid. Another object of the present invention is to provide a control method for the above electric vehicle charging station system with an energy storage device.

Technical solution: In order to realize the above-mentioned purpose of the invention, the technical solution adopted in the present invention is as follows:

An electric vehicle charging station system with an energy storage device, including an AC power supply grid, monitoring equipment, and charging equipment; the AC power grid is connected to the electric Vehicle charging station system; the monitoring equipment completes the monitoring and control of the electric vehicle charging station system, and guides the operation of the entire electric vehicle charging station system; it also includes energy storage equipment; the energy storage equipment contains several energy storage equipment groups, each energy storage equipment The group is composed of several switch controllers and energy storage devices; the charging equipment includes several charging equipment groups, and each charging equipment group is composed of several switch controllers and charging piles.

The energy storage method of the energy storage device adopts a single energy storage method or a combined energy storage method.

The energy storage element of the energy storage device is a single type of energy storage element or a combination of different types of energy storage elements.

A control method for the above-mentioned electric vehicle charging station system with an energy storage device. During the period of low power consumption, the energy storage equipment of the charging station is charged and stored; Car charging; during the peak hours of electricity shortage, the surplus electric energy is fed back to the grid for use by users.

The electric vehicle charging station system with energy storage device of the present invention is composed of AC power supply system, monitoring equipment, energy storage equipment, charging equipment and other parts.

The AC grid power supply system consists of a high-voltage relay protection cabinet, a three-phase transformer and a low-voltage relay protection cabinet; the high-voltage relay protection cabinet is connected between the high-voltage AC grid and the high-voltage side of the three-phase transformer, and the low-voltage side of the three-phase transformer Connect the low-voltage relay protection cabinet to achieve isolation and protection.

The monitoring equipment is the core of the whole system, which mainly completes system monitoring (including grid information monitoring, energy storage status monitoring, charging status monitoring), power flow control between energy storage equipment and AC grid (energy storage status or feedback status), storage The control between the functional equipment and the charging equipment (user) guides the operation status of the entire charging station system. When the electric vehicle is charging, that is, when there is an energy demand, the monitoring equipment monitors the energy reserve of the energy storage equipment of the system and the information of the power grid.

The energy storage equipment includes several energy storage equipment groups, and each energy storage equipment group is composed of several switch controllers and energy storage devices, and the number depends on the scale of the charging station to be built. The energy storage devices are lithium titanate batteries, super capacitors and other energy storage devices. When choosing an energy storage device, it is necessary to consider the cycle life of the device, operating temperature range, charging efficiency, energy density, scale of the charging station, and cost-effectiveness of the device, so as to optimize the configuration. At the same time, the energy storage device may adopt a single energy storage method or a combined energy storage method.

The charging equipment includes several charging pile groups, and each charging equipment group is composed of several switch controllers and charging piles, and the number depends on the scale of the charging station to be built.

Beneficial effects: Compared with the equipment in the prior art, the present invention has the following advantages: it can effectively reduce the impact of fast charging on the power grid, relieve the pressure on the power grid, and do not need large-scale expansion of the power grid substation connected to the charging station ; It can provide charging services for different manufacturers and different types of electric vehicles; the charging service is convenient, the operation is simple and flexible, and the maintenance is convenient; the electricity can be purchased and stored in the energy storage device when the electricity price is low, and the electricity price is high. The energy of the energy storage device is sold to electric vehicle customers or the grid during the peak of electricity consumption, so as to obtain greater profits and help the grid to cut peaks and flatten valleys.

Description of drawings

Fig. 1 is a schematic diagram of the composition of the electric vehicle charging station system with energy storage device according to the present invention.

Fig. 2 is a schematic diagram of the normal energy storage and charging operation of the electric vehicle charging station system with an energy storage device, which only contains one set of energy storage equipment and one set of charging equipment.

Figure 3 is a schematic diagram of using an electric vehicle charging station system with an energy storage device to feed surplus electric energy back to the grid during the peak period of grid power consumption, which only contains one set of energy storage equipment and one set of charging equipment.

Figure 4 is a schematic diagram of the normal fast charging operation of electric vehicles through charging equipment using the electric vehicle charging station system with energy storage devices, which only contains one set of energy storage equipment and one set of charging equipment.

Detailed ways

The present invention will be further explained below in conjunction with the accompanying drawings.

Configuration of electric vehicle charging station system:

As shown in FIG. 1 , it is a basic structural diagram of the electric vehicle charging station system with energy storage device of the present invention. The electric vehicle charging station system with energy storage device includes AC power supply grid 1, monitoring equipment 2, charging equipment 4 and energy storage equipment 3; The protection cabinet is connected to the electric vehicle charging station system; the monitoring device 2 completes the monitoring and control of the electric vehicle charging station system, and guides the operation of the entire electric vehicle charging station system; the energy storage device 3 contains several energy storage equipment groups, and each energy storage The equipment group is composed of several switch controllers and energy storage devices; the charging equipment 4 includes several charging equipment groups, and each charging equipment group is composed of several switch controllers and charging piles. Among them, the choice of energy storage equipment is particularly important. The energy storage device of the charging station can use a combination of supercapacitor and lithium titanate battery or a lithium titanate battery alone to form an energy storage device. Fast, high energy density, and although the energy density of the super capacitor is not high, it has a very high power density, can be charged and discharged with a large current, the charge and discharge speed is fast and the mode is simple, it is a real fast charge, and the service life long.

Generally, the capacity of an energy storage device is much greater than the energy required by a single electric vehicle. In order to better utilize energy and optimize charging efficiency, when configuring an electric vehicle charging station with an energy storage device, it can be one or several The energy storage device is equipped with several charging devices, for example, one energy storage device controls five electric vehicle charging devices.

Control method of electric vehicle charging station system:

As shown in FIG. 2 , it is a schematic diagram of a charging station with an energy storage device for normal energy storage and charging. Charging stations generally charge and store energy for energy storage devices during low power consumption periods. Low electricity consumption is usually at night, and the number of charging cars is also small. During this time period, the charging station obtains power from the grid at a normal charging rate to charge and store energy for the energy storage equipment of the charging station. The general charging and energy storage time is 6 -8 hours or so. The monitoring equipment mainly monitors information such as grid information and energy storage status of energy storage equipment.

During the daytime, it is the peak of electricity consumption. At this time, the charging station mainly supplies the stored electric energy to the electric vehicle users to charge the electric vehicles. The normal operation schematic diagram is shown in Figure 4. At this time, the monitoring equipment mainly monitors information such as grid information, remaining energy stored in energy storage equipment, and working status of chargers.

In addition, if the energy storage of the charging station has a large surplus in a certain period of time, during the peak hours of power consumption during the day, under the condition of ensuring the normal operation of the charging station, the charging station can feed back the surplus electric energy to the grid company according to the demand of the grid, so as to realize energy return. At this time, the energy flows from the energy storage device to the AC grid, and its operation schematic diagram is shown in Figure 3. Charging stations can still get extra revenue from the difference in the price of charging and discharging energy storage equipment. At this time, the monitoring device mainly monitors information such as grid information and energy margin stored by the energy storage device.

When the energy stored in the charging station cannot meet the electricity demand of the electric vehicle, the charging station can directly use the AC grid to charge the electric vehicle at a normal rate (non-fast charging) to maintain the normal operation of the charging station to a certain extent.

Maintenance extension of the electric vehicle charging station system:

If the number of electric vehicles in the area increases, the charging station needs to be expanded, and more energy storage devices and charging devices can be added. The investment is small and the expansion is simple.

If one or more energy storage devices need to be maintained or replaced, the device can be isolated by pulling the switch on the input and output sides of the device without affecting the normal operation of other devices, which is very simple and convenient.

Claims (4)

1. an electric automobile charging station system that has energy storage device comprises Alternating Current Power Supply electrical network, watch-dog and charging device; Described Alternating Current Power Supply electrical network inserts the electric automobile charging station system by high pressure relaying protection cabinet, three-phase transformer and low pressure relaying protection cabinet; Watch-dog is finished the monitoring of electric automobile charging station system and control, instructs the operation of whole electric automobile charging station system; It is characterized in that: also comprise energy storage device; Energy storage device contains some energy storage device groups, and each energy storage device group is made of some on-off controllers and energy storage device; Described charging device contains some charging device groups, and each charging device group is made of some on-off controllers and charging pile.

2. according to claims 1 described electric automobile charging station system that has energy storage device, it is characterized in that: the energy storage mode of described energy storage device adopts independent energy storage mode or combined accumulation energy mode.

3. according to claims 1 described electric automobile charging station system that has energy storage device, it is characterized in that: the energy-storage travelling wave tube of described energy storage device is the combination of the energy-storage travelling wave tube or the dissimilar energy-storage travelling wave tube of single type.

4. claims 1 described control method that has the electric automobile charging station system of energy storage device is characterized in that: the low power consumption period, carry out the charging energy storage of charging station energy storage device; The peak of power consumption period, give charging electric vehicle with energy storage device institute electric energy stored; Feed back to electrical network with the surplus electric energy peak period of shortage of electric power, uses for the user.

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