WO2021073049A1

WO2021073049A1 - Centralized energy storage charging pile

Info

Publication number: WO2021073049A1
Application number: PCT/CN2020/082293
Authority: WO
Inventors: 王渭渭; 朱春辉; 岳兴
Original assignee: 深圳英飞源技术有限公司
Priority date: 2019-10-18
Filing date: 2020-03-31
Publication date: 2021-04-22
Also published as: CN110626203A

Abstract

A centralized energy storage charging pile, comprising high-frequency isolation conversion bidirectional or unidirectional DC/DC converters (7, 8) and DC buses (10, 11), a first connection point of the DC/DC converter (7, 8) being connected to one or more groups of energy storage devices (9) by means of an energy storage bus (6), and a second connection point being connected to the DC buses (10, 11), and further comprising high-frequency isolation conversion bidirectional or unidirectional first and second AC/DC conversion devices (2, 4). By concentrating the electric energy of the energy storage devices on the energy storage bus, and combining the electric energy of an AC power grid and the electric energy of the battery in an electric vehicle, electric energy can freely flow among the energy storage bus, the AC power grid, and the battery of the electric vehicle, reducing the impact of electric vehicle charging on the AC power grid, the battery in the vehicle can be effectively utilized and used as a type of energy storage to reversely feed power to the power grid or charge the energy storage devices, and the electric energy of the energy storage devices can be used to charge the electric vehicle or feed the power grid so as to form an integrated solution.

Description

Centralized energy storage charging pile

Technical field

The invention relates to the field of charging piles, in particular to a centralized energy storage charging pile.

Background technique

Generally, electric vehicles get electricity from the AC grid, but due to the power supply limitations of the AC grid, especially the limited capacity of a single box transformer, it is impossible to connect to a charging pile that exceeds its capacity. At the same time, there may be certain differences in the electricity costs of the AC grid at different times, and the charging of electric vehicles is a random electricity consumption, so there are cases where the peak electricity fee is used or the full power cannot be charged. If the energy storage device is used to store electrical energy when the electricity bill is low or when the grid is idle, and release the electrical energy when the electricity is overloaded during high electricity bills or peak electricity consumption, it can greatly alleviate the power load limit and rate difference on the grid side. .

At the same time, there may be an application that needs to feed back the battery energy inside the electric vehicle to the grid or transfer it to an external energy storage device. For example, the electric vehicle is used as an energy storage device and fed back to the AC grid to the AC power equipment in the grid Power supply or charging piles perform battery performance testing by discharging the battery of the electric vehicle. The discharged electrical energy is stored in an external energy storage device, and the electrical energy in the external energy storage device can be subsequently charged back to the electric vehicle to save electrical energy.

In addition, due to the change in the configuration requirements of the capacity of the energy storage device, there are situations in which multiple energy storage devices are connected to the system at the same time in the large-capacity configuration. The charging port needs to share the energy of the energy storage device, and the energy storage device needs to be flexibly distributed to different charging ports. That is, it is necessary to flexibly distribute the electrical energy of multiple sets of energy storage devices in parallel to different charging ports.

technical problem

The technical problem to be solved by the present invention is a centralized energy storage charging pile that concentrates the energy of the energy storage device on the energy storage bus, and at the same time combines the AC grid power and the battery power in the electric vehicle, so that the three can be Free flow, reducing the impact of electric vehicle charging on the AC grid, and at the same time, it can effectively use the battery in the car and use it as a kind of energy storage, reverse feeding the grid or charging the energy storage device, and can also use the energy storage device at the same time. Electric energy is used to charge electric vehicles or feed power to the grid to form an integrated solution that effectively solves many deficiencies in existing technologies and products.

Technical solutions

The present invention is achieved through the following technical solutions: a centralized energy storage charging pile, including a high-frequency isolation conversion bidirectional or unidirectional DC/DC conversion device and a DC bus; the first connection point of the DC/DC device is through the energy storage The bus is connected to one or more groups of energy storage devices; the second connection point is connected to the DC bus;

It also includes two-way or one-way first and second AC/DC conversion devices for high-frequency isolation conversion; the first connection point of the AC/DC conversion device is connected to the AC power grid, the second connection point is connected to the DC bus, and the AC/DC conversion device After high-frequency isolation and transformation of the AC power grid, the DC bus is supplemented with power or the DC bus power is fed back to the AC grid;

It also includes a bidirectional or unidirectional third AC/DC conversion device for high-frequency isolation conversion; the first connection point of the third AC/DC conversion device is connected to the AC power grid, and the second connection point is connected to the energy storage bus and passes through the storage bus. The energy bus is connected to the energy storage device, and the AC/DC conversion device converts the AC power from the AC grid through high-frequency isolation and conversion through the energy storage bus to charge the energy storage device or feed the energy storage device back to the AC grid;

It also includes a device for charging an electric vehicle. The first connection point of the charging device is a DC bus, and the second connection point is an electric vehicle charging port. The DC is dynamically adjusted according to the requirements of electric vehicle charging or discharging voltage, current, and power. The voltage, current and power of the bus bar charge the electric vehicle; at the same time, the battery power of the electric vehicle is released through the electric vehicle charging port, stored in the energy storage device through the two-way DCDC conversion device or directly fed back to the grid through the two-way ACDC conversion device;

It also includes system master control, unified management of energy storage charging piles and its internal single/bidirectional ACDC conversion device, single/bidirectional DCDC conversion device, charging and discharging management of electric vehicles, charging and discharging management of energy storage devices, and different energy storage charging piles Energy management between.

As a preferred technical solution, more than one DC/DC conversion device is provided, which includes a first DC/DC conversion device and a second DC/DC conversion device. The first and second DC/DC conversion devices are bidirectional and store energy. The electrical energy of the device is charged and discharged bidirectionally with the DC bus after high-frequency isolation and conversion; the first and second DC/DC conversion devices are unidirectional, and the electrical energy of the energy storage device is unidirectionally discharged with the DC bus after high-frequency isolation and conversion. , Wherein the DC bus includes more than one, including a first DC bus and a second DC bus, wherein more than one electric vehicle charging port is provided, which includes a first electric vehicle charging port and a second electric vehicle charging port.

As a preferred technical solution, a power switching device between multiple DC busbars is also included to realize the output power switching combination between multiple DC busbars.

As a preferred technical solution, the high-frequency isolation bidirectional DC/DC conversion device has two direction conversions, the first direction conversion: the DC power of the energy storage device passes through the energy storage bus, and is output to the DC bus through the high-frequency isolation conversion; Two-direction conversion: the DC bus energy is reversely converted through high-frequency isolation, output to the energy storage bus, and stored in the energy storage device; when a high-frequency isolation unidirectional DC/DC conversion device is used, only the first direction conversion is performed.

As a preferred technical solution, a one-way or two-way DC/DC conversion device has an external communication bus connected to the system main control, and the system main control communicates with the DC/DC to control the discharge of the energy storage device to the DC bus. , Or the charging of the energy storage device by the DC bus, and the voltage, current and power of the charging and discharging conversion.

As a preferred technical solution, one or more energy storage devices are connected in parallel to an energy storage bus connected to the energy storage device, and there are one or more such energy storage buses in a charging pile corresponding to one or more energy storage devices .

As a preferred technical solution, there is a DC bus connected to the charging port of an electric vehicle. When in a charging pile, there can be one or more DC buses, corresponding to one or more electric vehicle charging ports, and the DC bus passes through the switching device. Phase connection to realize the expansion and increase of charging port power and power switching.

As a preferred technical solution, a type of high-frequency isolation unidirectional or bidirectional AC/DC conversion device is included. The high-frequency isolation bidirectional AC/DC conversion device has two-direction conversion. The first direction conversion: AC grid power passes through the high-frequency isolation Transform, output to the energy storage bus, and store the electrical energy in the energy storage device; second direction transformation: the DC electrical energy of the energy storage unit passes through the energy storage bus, through the high-frequency isolation transformation, and output to the AC grid, when the high frequency is selected When the unidirectional AC/DC converter is isolated, only the first direction conversion is performed.

As a preferred technical solution, the high-frequency isolation AC/DC converter has a communication bus externally: the communication bus is connected to the main control of the system, and communicates with the AC/DC converter through the main control of the system to control the communication between the AC power grid and the energy storage bus The direction of the electrical energy conversion and the conversion power.

As a preferred technical solution, a type of high-frequency isolation unidirectional or bidirectional AC/DC conversion device is included. The high-frequency isolation bidirectional AC/DC conversion device has two-direction conversion. The first direction conversion: AC grid power can be isolated by high-frequency The conversion device outputs to the DC bus and is connected to the charging port of the electric vehicle through the DC bus to charge the electric vehicle; the second direction conversion: the battery power inside the electric vehicle passes through the same charging port, is connected to the DC bus, and passes through the High-frequency isolation conversion, output to the AC grid, when the high-frequency isolation unidirectional AC/DC conversion device is selected, only the first direction conversion is performed.

As a preferred technical solution, the high-frequency isolation AC/DC converter has a communication bus externally: the communication bus is connected to the main control of the system, and communicates with the AC/DC converter through the main control of the system to control the communication between the AC power grid and the DC bus. Electric energy conversion direction and conversion power.

As a preferred technical solution, the system main control is a single integrated centralized main control, or a distributed main control composed of a combination of multiple control units with a hierarchical structure.

Beneficial effect

The beneficial effect of the present invention is that the present invention realizes the free flow of electric energy among the three through the connection of the DC bus, the energy storage bus and the AC line through the high-frequency isolated bidirectional or unidirectional conversion device. The system master control performs optimal electric energy flow control according to the current electric vehicle charging requirements, the electric energy storage state of the energy storage device, the state of the AC grid, and the scheduling of the energy management background system that may be connected.

Description of the drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work.

Figure 1 is a schematic diagram of the overall structure of the present invention;

Fig. 2 is a schematic structural diagram of the first embodiment of the present invention.

Embodiments of the present invention

All the features disclosed in this specification, or all disclosed methods or steps in the process, except for mutually exclusive features and/or steps, can be combined in any manner.

Any feature disclosed in this specification (including any appended claims, abstract and drawings), unless specifically stated, can be replaced by other equivalent or alternative features with similar purposes. That is, unless otherwise stated, each feature is just one example of a series of equivalent or similar features.

In the description of the present invention, it should be understood that the terms "one end", "the other end", "outer", "upper", "inner", "horizontal", "coaxial", "central", "end" "," "length", "outer end", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying the pointed device or The element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention.

In addition, in the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

The terms such as "upper", "above", "below", "below" and the like used in the present invention to indicate a relative position in space are for the purpose of facilitating explanation to describe one unit or feature as shown in the drawings relative to another. The relationship of a unit or feature. The terms of relative spatial position may be intended to include different orientations of the device in use or operation other than those shown in the figures. For example, if the device in the figure is turned over, the units described as being "below" or "below" other units or features will be "above" the other units or features. Therefore, the exemplary term "below" can encompass both the above and below orientations. The device can be oriented in other ways (rotated by 90 degrees or other orientations), and the space-related descriptors used herein are explained accordingly.

In the present invention, unless otherwise clearly specified and limited, the terms "set", "socket", "connection", "through", "plugging" and other terms should be understood in a broad sense. For example, it may be a fixed connection. It can also be detachably connected or integrated; it can be mechanically connected or electrically connected; it can be directly connected or indirectly connected through an intermediate medium, which can be the internal communication of two components or the interaction of two components Relationship, unless explicitly defined otherwise. For those of ordinary skill in the art, the specific meanings of the above-mentioned terms in the present invention can be understood according to specific circumstances.

As shown in Fig. 1, a first bidirectional or unidirectional DC/DC converter 7 and a second bidirectional or unidirectional DC/DC converter 8 that include high-frequency isolation conversion, as well as a first DC bus 10 and a second DC bus 11; The first connection point of the DC/DC converter is connected to the energy storage device 9 through the energy storage bus 6, and the second connection point is connected to the first DC bus 10 and the second DC bus 11; if it is a two-way DC/DC converter , The electric energy of the energy storage device 9 is subjected to bidirectional exchange with the first DC bus 10 and the second DC bus 11 after being transformed by the energy storage bus 6 through high-frequency isolation.

If it is only a one-way DC/DC conversion device, the electrical energy of the energy storage device 9 is converted through the energy storage bus 6 through high-frequency isolation and then exchanges unidirectionally with the first DC bus 10 and the second DC bus 11; This includes two sets of parallel energy storage devices, two sets of DC buses and two sets of charging ports. In actual use, it can be one or more sets of energy storage devices in parallel, one or more sets of DC buses and one or Multiple charging ports. There can be one or more DC/DC converters.

In this embodiment, the high-frequency isolation bidirectional DC/DC conversion has two direction conversions, the first direction conversion: the DC power of the energy storage unit is converted and output to the DC bus, so that the power of the energy storage device can be used to charge the electric vehicle; Direction conversion: The DC bus is input to the energy storage device through high-frequency isolation conversion, so that the electric energy of the electric vehicle can be fed back to the energy storage device.

As shown in Figure 1, it includes an AC power grid 1, a one-way or two-way first high-frequency isolation AC/DC conversion device 2 and a one-way or two-way first high-frequency isolation AC/DC conversion device 4; high-frequency isolation AC/DC conversion The first connection point of the device is the AC power grid 1, and the second connection point is the first DC bus 10 and the second DC bus 11. The AC/DC converter converts AC power into DC power to the first DC bus 10 and the second DC bus. DC bus 11; if the high-frequency isolation AC/DC conversion device is bidirectional, the electric energy of the first DC bus 10 and the second DC bus 11 can be fed back to the AC power grid in reverse. Figure 1 is just a schematic diagram that includes two sets of DC buses and two sets of AC/DC converters. In actual use, it can be one or more sets of DC buses, one or more sets of AC/DC converters.

In this embodiment, if the high-frequency isolation AC/DC is a two-way conversion device, the conversion has two conversion directions. The first direction conversion: the AC grid power is converted and output to the DC bus to realize the release of the AC power to the electric vehicle; Direction conversion: The DC bus is fed back to the AC power grid through high-frequency isolation conversion, so that the electric energy of the electric vehicle is fed back to the AC power grid. If the high-frequency isolation AC/DC is only a one-way conversion device, only the first direction conversion is performed to realize the release of AC power to the electric vehicle.

As shown in Figure 1, it includes an AC power grid 1, a one-way or two-way third high-frequency isolation AC/DC converter 3, and an energy storage bus 6; the first connection point of the AC/DC converter is the AC power grid 1, and the second connection The point is connected to the energy storage bus 6 and connected to the energy storage device 9 through the energy storage bus. If it is a two-way AC/DC conversion device, the electrical energy of the energy storage device 9 is passed through the energy storage bus 6, and then exchanged with the AC grid 1 after high-frequency isolation conversion; if it is only a one-way AC/DC conversion device, only The energy storage device 9 is charged through the energy storage bus 6 after transforming the AC grid power through high frequency isolation. Figure 1 is only a schematic diagram containing two groups of energy storage devices connected in parallel. In the actual power appeal, one or more groups of energy storage devices can be connected in parallel, and there can be one or more AC/DC conversion devices.

In this embodiment, if the high-frequency isolated AC/DC is a two-way conversion device, the conversion has two conversion directions. The first direction conversion: the AC power grid is converted and output to the energy storage bus to realize the release of the AC power to the energy storage device; The second direction conversion: the energy storage device feeds back to the AC grid through the energy storage bus through high-frequency isolation conversion, and realizes the energy storage device's electrical energy feedback to the AC grid. If the high-frequency isolation AC/DC is only a one-way conversion device, only the first direction conversion is performed to realize the release of AC electrical energy to the energy storage device.

As shown in FIG. 1, it includes a first DC bus 10 and a second DC bus 11, a bus parallel switching device 14, and a first electric vehicle charging and discharging port 12 and a second electric vehicle charging and discharging port 13. The DC bus is connected to the corresponding charging and discharging port of the electric vehicle through the power distribution device. Figure 1 is only a schematic diagram that includes two sets of DC buses and two sets of charging ports. In actual use, it can be one or more sets of DC buses, one or more sets of charging and discharging ports for electric vehicles, and the switching device 14 can be one set. There can also be no or multiple groups.

As shown in Figure 1, it includes the system main control 5. The system main control communicates with electric vehicles, AC/DC converters, DC/DC converters and energy storage devices through the communication bus, and collects energy storage device information and electric vehicle charging information , Combined with the state of the AC grid and the power state of other charging systems in the network, the AC/DC converter is used to control the AC power acquisition value and power direction, and the DC/DC converter is used to control the power direction and power direction of the energy storage device. The power size and the charging power of electric vehicles and even the discharge power of electric vehicles to the DC bus can be controlled through the charging port to meet the optimal use of electric energy.

Embodiment 1

As shown in Figure 2, the photovoltaic array A is connected to the energy storage bus through the MPPT maximum power tracking conversion device B,

The foregoing embodiment is a photovoltaic energy storage charging system. Electric energy can be supplemented by a photovoltaic array. The energy storage bus is powered by maximum power tracking, and then the electric vehicle is powered by the DC bus. The excess energy is stored in the energy storage device. When there is no solar energy or solar energy is not enough, use AC power or energy storage device to discharge to provide electrical energy to the DC bus to ensure the electrical energy for charging the electric vehicle.

The above are only specific implementations of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or replacements that are not thought of through creative work shall be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope defined by the claims.

Claims

A centralized energy storage charging pile, which is characterized by: a bidirectional or unidirectional DC/DC conversion device containing high-frequency isolation conversion and a DC bus; the first connection point of the DC/DC device is connected to one or more groups through the energy storage bus In the group energy storage device; the second connection point is connected to the DC bus;

It also includes two-way or one-way first and second AC/DC conversion devices for high-frequency isolation conversion; the first connection point of the AC/DC conversion device is connected to the AC power grid, the second connection point is connected to the DC bus, and the AC/DC conversion device After high-frequency isolation and transformation of the AC power grid, the DC bus can be supplemented with power or the DC bus power will be fed back to the AC grid;

It also includes a bidirectional or unidirectional third AC/DC conversion device for high-frequency isolation conversion; the first connection point of the third AC/DC conversion device is connected to the AC power grid, and the second connection point is connected to the energy storage bus and passes through the storage bus. The energy bus is connected to the energy storage device, and the AC/DC conversion device converts the AC power from the AC grid through high-frequency isolation and conversion through the energy storage bus to charge the energy storage device or feed the energy storage device back to the AC grid;

It also includes a device for charging an electric vehicle. The first connection point of the charging device is a DC bus, and the second connection point is an electric vehicle charging port. The DC is dynamically adjusted according to the requirements of electric vehicle charging or discharging voltage, current, and power. The voltage, current and power of the bus bar charge the electric vehicle; at the same time, the battery power of the electric vehicle is released through the electric vehicle charging port, stored in the energy storage device through the two-way DCDC conversion device or directly fed back to the grid through the two-way ACDC conversion device;

It also includes system master control, unified management of energy storage charging piles and its internal single/bidirectional ACDC conversion device, single/bidirectional DCDC conversion device, charging and discharging management of electric vehicles, charging and discharging management of energy storage devices, and different energy storage charging piles Energy management between.
The centralized energy storage charging pile according to claim 1, wherein there is more than one DC/DC conversion device, which includes a first DC/DC conversion device and a second DC/DC conversion device. 2. The DC/DC conversion device is bidirectional, and the electric energy of the energy storage device is subjected to high-frequency isolation and conversion and then is charged and discharged bidirectionally with the DC bus; the first and second DC/DC converters are unidirectional and pass the electric energy of the energy storage device through After high-frequency isolation and transformation, it performs unidirectional discharge with the DC bus. Among them, the DC bus includes more than one, including the first DC bus and the second DC bus, and the electric vehicle charging port is provided with more than one, which includes the first electric vehicle charging Port and the second electric vehicle charging port.
8. The centralized energy storage charging pile according to claim 1, further comprising a power switching device between multiple DC bus bars to realize output power switching combination between multiple DC bus bars.
The centralized energy storage charging pile according to claim 1, characterized in that: the high-frequency isolation bidirectional DC/DC conversion device has two direction conversions. The first direction conversion: the DC power of the energy storage device passes through the energy storage bus The high-frequency isolation conversion is output to the DC bus; the second direction conversion: the DC bus energy is reversed through the high-frequency isolation conversion, output to the energy storage bus, and the energy is stored in the energy storage device; when high-frequency isolation unidirectional DC/ The DC conversion device only performs the first direction conversion.
The centralized energy storage charging pile according to claim 1, characterized in that: a one-way or two-way DC/DC conversion device has a communication bus connected to the system master, and communicates with the DC/DC through the system master , To control the electric energy of the energy storage device to discharge the DC bus, or the DC bus to charge the energy storage device, as well as the voltage, current and power of the charge and discharge conversion.
The centralized energy storage charging pile according to claim 1, wherein one or more energy storage devices are connected in parallel on an energy storage bus connected to the energy storage device, and there are one or more such energy storage devices in a charging pile. The energy storage bus bar corresponds to one or more energy storage devices.
The centralized energy storage charging pile according to claim 1, characterized in that: there is a DC bus connected to the charging port of an electric vehicle. In a charging pile, there can be one or more DC buses, corresponding to 1 or The multiple electric vehicle charging ports and the DC bus are connected through a switching device to realize the expansion and increase of the power of the charging port and the power switching.
The centralized energy storage charging pile according to claim 1, characterized in that it comprises a type of high-frequency isolation unidirectional or bidirectional AC/DC conversion device, and the high-frequency isolation bidirectional AC/DC conversion device has two-directional conversion. One direction conversion: the AC grid power is converted through the high-frequency isolation, output to the energy storage bus, and stored in the energy storage device; the second direction conversion: the DC power of the energy storage unit passes through the energy storage bus, and is converted through the high-frequency isolation , Output to the AC grid, when the high-frequency isolation unidirectional AC/DC conversion device is selected, only the first direction conversion is performed.
The centralized energy storage charging pile according to claim 1, characterized in that: a high-frequency isolated AC/DC conversion device has a communication bus externally: the communication bus is connected to the main control of the system, and the AC/DC conversion device is connected through the main control of the system. Communication to control the direction of electric energy conversion and conversion power between the AC grid and the energy storage bus.
The centralized energy storage charging pile according to claim 1, characterized in that it comprises a type of high-frequency isolation unidirectional or bidirectional AC/DC conversion device, and the high-frequency isolation bidirectional AC/DC conversion device has two-directional conversion. One direction conversion: the AC grid power can be output to the DC bus through the high-frequency isolation conversion device, and connected to the electric vehicle charging port through the DC bus to charge the electric vehicle; the second direction conversion: the battery power inside the electric vehicle passes through the same A charging port is connected to the DC bus, and outputs to the AC grid through the high-frequency isolation conversion. When the high-frequency isolation unidirectional AC/DC conversion device is selected, only the first direction conversion is performed.
The centralized energy storage charging pile according to claim 1, characterized in that: a high-frequency isolated AC/DC conversion device has a communication bus externally: the communication bus is connected to the main control of the system, and the AC/DC conversion device is connected through the main control of the system. Communication to control the direction and power conversion between the AC power grid and the DC bus.
The centralized energy storage charging pile according to claim 1, characterized in that: the system main control is a single integrated centralized main control, or a distributed main control composed of a combination of multiple control units with a hierarchical structure.