CN115940227A - High-voltage direct-hanging charging pile and control method thereof - Google Patents
High-voltage direct-hanging charging pile and control method thereof Download PDFInfo
- Publication number
- CN115940227A CN115940227A CN202211531477.3A CN202211531477A CN115940227A CN 115940227 A CN115940227 A CN 115940227A CN 202211531477 A CN202211531477 A CN 202211531477A CN 115940227 A CN115940227 A CN 115940227A
- Authority
- CN
- China
- Prior art keywords
- voltage
- charging pile
- direct
- unit
- bridge
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/60—Other road transportation technologies with climate change mitigation effect
- Y02T10/70—Energy storage systems for electromobility, e.g. batteries
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/60—Other road transportation technologies with climate change mitigation effect
- Y02T10/7072—Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
Landscapes
- Charge And Discharge Circuits For Batteries Or The Like (AREA)
Abstract
The invention provides a high-voltage direct-hanging charging pile and a control method thereof, which relate to the technical field of high-voltage distribution network outlet charging devices and comprise a control unit, and an energy storage unit, an inversion unit, a filtering unit, a high-frequency transformer and a dynamic voltage regulation unit which are sequentially connected, wherein the energy storage unit, the inversion unit, the filtering unit, the high-frequency transformer and the dynamic voltage regulation unit are respectively connected with a distribution network and a direct-current charging pile; the control unit is respectively connected with the inversion unit, the power distribution network and the energy storage unit; the compensation voltage is determined according to the difference value of the output voltage of the power distribution network and the rated input voltage of the direct-current charging pile, after the compensation voltage is superposed with the output voltage of the power distribution network, the superposed voltage is transmitted to the direct-current charging pile, the characteristic of energy dynamic exchange and the electrical isolation between the energy storage module and the charging pile module are realized through the cooperation of the charging pile control circuit and the energy storage module, and the reliability of the high-voltage direct-hanging charging pile is improved.
Description
Technical Field
The invention relates to the technical field of charging devices at outlets of high-voltage distribution networks, in particular to a high-voltage direct-hanging charging pile and a control method thereof.
Background
From the current domestic situation, the carbon emission of electric power accounts for an absolutely important part, and the carbon dioxide emission percentage of manufacturing industry, building and traffic departments is relatively high. In the next decades, the process of realizing carbon neutralization changes the domestic energy consumption structure deeply, the energy field is changed fundamentally, and the realization of carbon neutralization in China starts from two aspects of energy supply and energy utilization in the future. At the energy supply end, fossil energy power generation is a main source of carbon emission of the power department, and the renewable energy sources such as photovoltaic energy, wind power and the like are mainly used for replacing and reducing emission in the future; energy consumption, new energy utilization in the traffic field and electromotion in the industrial field are main emission reduction modes.
Electric vehicles have attracted much attention and have rapidly developed as one of the important ways to solve energy crisis and environmental pollution. The development and the use of new energy automobiles can guarantee the energy safety of China and protect the ecological environment, the new energy automobiles are supported by the governments and enterprises with great strength, and the quantity of new energy automobiles in China is 417 thousands of automobiles when the year is up to 6 months in 2020, and is increased by 36 thousands of automobiles and 9.45% compared with the year in 2019. In 2025, the new energy automobile sales volume reaches about 20% of the total automobile sales volume, and the battery charging and replacing service network is convenient and efficient. The electric automobile can be operated as a power supply or a load, if the electric automobile is operated as an unadjustable load, the problems of volatility, intermittency, inverse peak regulation characteristics and the like exist, the stability and the reliability of a power grid are seriously damaged when the electric automobile is accessed in a high proportion, and great challenges are brought to the voltage and frequency control of a power distribution network. Therefore, if a large-scale application of distributed loads is to be realized, energy management strategies must be researched to solve the source-load coordination control. The micro-grid is used as an independent integral operation capable of realizing self-control, protection and energy management, an interactive intermediate layer is formed among the power grid, users and the distributed power supplies, the adverse effect of a large number of distributed access of the distributed power supplies on the power grid is effectively reduced by improving the level of coordinated operation of the three, and meanwhile, the requirements of the users on power supply reliability and diversity can be met. The micro-grid can be divided into a direct current micro-grid, an alternating current micro-grid and an alternating current and direct current hybrid micro-grid according to the type of the voltage of the public bus. A plurality of alternating current-direct current conversion links are required to be added for alternating current grid connection, so that the overall efficiency is reduced; and the direct current is connected to the grid and supplied with power, so that the conversion frequency of the electric energy can be reduced. Moreover, compared with an alternating-current power distribution network, the direct-current power distribution network has the advantages of smaller occupied area, stronger power supply capacity and more flexible control capacity. Therefore, the inherent dc power generation of most renewable energy sources and the rapid growth of dc loads make dc micro-grids a more attractive option in power systems.
Compared with an alternating-current power distribution network, the direct-current power distribution power quality has no frequency and phase problems, and is higher in power quality, but the critical power quality problem still exists in the current direct-current power distribution system. Distributed power sources in the direct-current micro-grid are more, and the output power of the distributed power sources is unstable, so that the direct-current micro-grid is easy to cause the problem of electric energy quality: in a low-voltage direct-current power distribution network, power imbalance in the power distribution network can be caused by changes of factors such as distributed power supply output, load, system operation mode and the like, and the root cause of voltage deviation in a direct-current micro-grid is the power imbalance.
At present, direct current microgrid power quality problem treatment equipment research is less. In order to avoid the influence of voltage disturbance on the output power and the output voltage quality of the charging pile, the key and sensitive loads can be protected from a series of voltage deviations such as voltage drop and sudden rise of a power supply end by adding the dynamic voltage regulating unit in the high-voltage direct-hanging charging pile. At present, research on high-voltage direct-hanging technology is mostly focused on the field of energy storage systems, and much research on alternating-current power conversion systems is focused on, and few researches on direct-current charging pile technology for realizing voltage stabilization by combining energy storage modules are focused on.
Disclosure of Invention
The invention aims to provide a high-voltage direct-hanging charging pile and a control method thereof, which realize the characteristic of dynamic energy exchange and the electrical isolation between an energy storage module and a charging pile module through the matching of a charging pile control circuit and the energy storage module, and improve the reliability of the high-voltage direct-hanging charging pile.
In order to achieve the purpose, the invention provides the following scheme:
a high voltage direct-hanging charging pile, comprising:
the control unit, and the energy storage unit, the inversion unit, the filtering unit, the high-frequency transformer and the dynamic voltage regulation unit which are connected in sequence;
the dynamic voltage regulating unit is also respectively connected with the power distribution network and the direct current charging pile;
the control unit is respectively connected with the inversion unit, the power distribution network and the energy storage unit;
the control unit is used for controlling the energy storage unit to output direct-current voltage and controlling the inversion unit to invert the direct-current voltage into alternating-current voltage when the difference value between the output voltage of the power distribution network and the rated input voltage of the direct-current charging pile is not zero;
the filtering unit is used for filtering the alternating voltage;
the high-frequency transformer is used for performing frequency-boosting and voltage-boosting treatment on the filtered alternating-current voltage;
and the dynamic voltage adjusting unit is used for adjusting the direction of the alternating-current voltage subjected to the frequency-boosting and voltage-boosting treatment according to the positive and negative of the difference value to obtain a compensation voltage, and transmitting the superposed voltage to the direct-current charging pile after superposing the compensation voltage and the output voltage of the power distribution network.
Optionally, the inverter unit specifically includes:
the first full-bridge inverter structure and the first capacitor;
the first capacitor is connected with the energy storage unit;
the first full-bridge inversion structure comprises two parallel half-bridge structures; each half-bridge structure comprises two bridge arms connected in series; each bridge arm comprises a switching device and a diode which are connected in parallel;
two public ends obtained by connecting two half-bridge structures in parallel in a first full-bridge inversion structure are respectively connected with two ends of the first capacitor;
the public ends of two bridge arms in the first full-bridge inversion structure are respectively connected with a filtering unit; and the common ends of the bridge arms are the common ends of two bridge arms in the same half-bridge structure.
Optionally, the filtering unit specifically includes:
a first inductor, a second inductor and a second capacitor;
the first end of the first inductor and the first end of the second inductor are respectively connected with the common ends of two bridge arms in the first full-bridge inversion structure;
the second end of the first inductor and the second end of the second inductor are respectively connected with two ends of the second capacitor;
and two ends of the second capacitor are respectively connected with two ends of the primary side of the high-frequency transformer.
Optionally, the energy storage unit is a storage battery.
Optionally, the dynamic voltage adjusting unit specifically includes:
a second full-bridge inverter structure and a third capacitor;
the second full-bridge inversion structure has the same structure as the first full-bridge inversion structure;
two public ends obtained by connecting two half-bridge structures in parallel in the second full-bridge inversion structure are respectively connected with the power distribution network and the direct current charging pile;
two public ends obtained by connecting two half-bridge structures in parallel in the second full-bridge inverter structure are also respectively connected with two ends of the third capacitor;
and the public ends of two bridge arms in the second full-bridge inversion structure are respectively connected with two ends of the secondary side of the high-frequency transformer.
Optionally, the dynamic voltage adjusting unit further includes:
a bypass switch;
the bypass switch is connected in parallel with the third capacitor.
Optionally, the dc dynamic voltage regulator further includes:
a third inductor;
the third inductor is arranged between the dynamic voltage regulating unit and the direct current charging pile.
A control method of a high-voltage direct-hanging charging pile is applied to the high-voltage direct-hanging charging pile and comprises the following steps:
acquiring the output voltage of the power distribution network;
when the difference value between the output voltage of the power distribution network and the rated input voltage of the direct current charging pile is not zero, controlling the energy storage unit to output direct current voltage, and controlling the inversion unit to invert the direct current voltage into alternating current voltage;
filtering the alternating voltage;
performing frequency boosting and voltage boosting treatment on the alternating-current voltage after the filtering treatment;
and adjusting the direction of the AC voltage subjected to the frequency and voltage boosting treatment according to the positive and negative of the difference value to obtain a compensation voltage, and after the compensation voltage is superposed with the output voltage of the power distribution network, transmitting the superposed voltage to the DC charging pile.
Optionally, the direction of the ac voltage after the frequency boosting and voltage boosting processing is adjusted according to the positive and negative of the difference value to obtain the compensation voltage, and the method specifically includes:
when the difference value is larger than zero, determining that the direction of the compensation voltage is opposite to the direction of the output voltage of the power distribution network, and enabling the energy storage unit to absorb redundant power;
and when the difference value is less than zero, determining that the direction of the compensation voltage is the same as the direction of the output voltage of the power distribution network, and releasing redundant power by the energy storage unit.
According to the specific embodiment provided by the invention, the invention discloses the following technical effects:
the invention provides a low-cost ultrahigh-power high-voltage direct-hanging charging pile and a control method thereof, wherein the charging pile comprises a control unit, and an energy storage unit, an inversion unit, a filtering unit, a high-frequency transformer and a dynamic voltage regulation unit which are sequentially connected are also respectively connected with a power distribution network and a direct-current charging pile; the control unit is respectively connected with the inversion unit, the power distribution network and the energy storage unit; the method comprises the steps of determining a compensation voltage according to a difference value between the output voltage of a power distribution network and the rated input voltage of a direct current charging pile, superposing the compensation voltage and the output voltage of the power distribution network, transmitting the superposed voltage to the direct current charging pile, absorbing or releasing power generated by the compensation voltage through an isolation transformer by an energy storage unit, and connecting the energy storage unit with the power distribution network through a bidirectional converter to supplement energy in a fault state. The characteristic of energy dynamic exchange and the electrical isolation between the energy storage module and the charging pile module are realized through the matching of the charging pile control circuit and the energy storage module, and the reliability of the high-voltage direct-hanging charging pile is improved.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without inventive exercise.
Fig. 1 is a schematic structural diagram of a high-voltage direct-hanging charging pile according to an embodiment of the invention;
fig. 2 is a first working schematic diagram of a high-voltage direct-hanging charging pile according to an embodiment of the present invention;
fig. 3 is a second working schematic diagram of a high-voltage direct-hanging charging pile according to an embodiment of the present invention;
fig. 4 is a flowchart of a method for controlling a low-cost ultrahigh-power high-voltage direct-hanging charging pile according to a second embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The invention aims to provide a high-voltage direct-hanging charging pile and a control method thereof, which realize the characteristic of dynamic energy exchange and the electrical isolation between an energy storage module and a charging pile module through the matching of a charging pile control circuit and the energy storage module, and improve the reliability of the high-voltage direct-hanging charging pile.
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.
Example one
As fig. 1, this embodiment provides a high voltage direct-hanging charging pile, includes:
the control unit, and the energy storage unit, the inversion unit, the filtering unit, the high-frequency transformer and the dynamic voltage regulation unit which are connected in sequence;
the dynamic voltage regulating unit is also respectively connected with the power distribution network and the direct current charging pile;
the control unit is respectively connected with the inversion unit, the power distribution network and the energy storage unit;
the control unit is used for controlling the energy storage unit to output direct-current voltage and controlling the inversion unit to invert the direct-current voltage into alternating-current voltage when the difference value between the output voltage of the power distribution network and the rated input voltage of the direct-current charging pile is not zero;
the filtering unit is used for filtering the alternating-current voltage;
the high-frequency transformer is used for performing frequency-boosting and voltage-boosting treatment on the filtered alternating-current voltage;
the dynamic voltage adjusting unit is used for adjusting the direction of the alternating-current voltage subjected to the frequency-boosting and voltage-boosting treatment according to the positive and negative of the difference value to obtain compensation voltage, and transmitting the superposed voltage to the direct-current charging pile after the compensation voltage is superposed with the output voltage of the power distribution network.
Wherein, the contravariant unit specifically includes:
the first full-bridge inverter structure and the first capacitor;
the first capacitor is connected with the energy storage unit;
the first full-bridge inversion structure comprises two parallel half-bridge structures; each half-bridge structure comprises two bridge arms connected in series; each bridge arm comprises a switching device and a diode which are connected in parallel;
two public ends obtained by connecting two half-bridge structures in parallel in the first full-bridge inversion structure are respectively connected with two ends of the first capacitor;
the public ends of two bridge arms in the first full-bridge inversion structure are respectively connected with a filtering unit; the common end of the bridge arms is the common end of two bridge arms in the same half-bridge structure.
Specifically, the filtering unit specifically includes:
a first inductor, a second inductor and a second capacitor;
the first end of the first inductor and the first end of the second inductor are respectively connected with the common ends of two bridge arms in the first full-bridge inversion structure;
the second end of the first inductor and the second end of the second inductor are respectively connected with the two ends of the second capacitor;
and two ends of the second capacitor are respectively connected with two ends of the primary side of the high-frequency transformer.
Specifically, the energy storage unit is a storage battery.
Specifically, the dynamic voltage adjustment unit specifically includes:
a second full-bridge inverter structure and a third capacitor;
the second full-bridge inversion structure has the same structure as the first full-bridge inversion structure;
two public ends obtained by connecting two half-bridge structures in parallel in the second full-bridge inversion structure are respectively connected with the power distribution network and the direct current charging pile;
two public ends obtained by connecting two half-bridge structures in parallel in the second full-bridge inversion structure are also respectively connected with two ends of a third capacitor;
and the public ends of two bridge arms in the second full-bridge inversion structure are respectively connected with two ends of the secondary side of the high-frequency transformer.
In addition, the dynamic voltage adjusting unit further includes:
a bypass switch;
the bypass switch is connected in parallel with the third capacitor.
In addition, the electric pile is directly hung to super large power high pressure of low-cost that this embodiment provided, electric pile is directly hung to high pressure still includes:
a third inductor;
the third inductor is arranged between the dynamic voltage regulating unit and the direct current charging pile.
As shown in fig. 1, in this embodiment, a direct current bidirectional topology based on a 10kV high voltage direct hanging is adopted, the system can interact with a user through a cloud, and the user can check charging information and the like on a mobile phone by using an APP. A dynamic voltage adjusting unit is arranged between the direct current bus and the charging pile, and the energy storage unit is partially connected into a voltage regulator through a high-frequency circuit. Satisfy different charging user's that charge demand through dynamic direct current voltage regulation to prevent to influence the net side power supply because of the electric energy quality reduction that outside electric automobile and other alternating current-direct current loads lead to.
1 high-voltage direct-hanging power station main component
The 10kV direct-hanging multi-Energy complementary charging station system mainly comprises a cloud Energy Management System (EMS), a local control system, a high-voltage super-charging module, an Energy storage module and an alternating current/direct current load. And the cloud EMS system sends instructions to each local intelligent terminal and receives data such as real-time electricity consumption, pricing and the like to perform dynamic energy management. Through real-time regulation and control bus voltage level in order to adapt to the electric pile demand of filling, record each place charging case periodicity and interim maintenance, examination etc. simultaneously, realize the full life cycle management to equipment. In addition, the EMS can send an instruction to the local terminal to enable the energy storage unit to work in a feeding state, and if necessary, the Vehicle-to-grid (V2G) feeding can be adopted, so that energy detailed management is really realized.
The local control system is used for realizing data processing, man-machine interaction and local management and allocation of energy. And controlling the overcharge module to charge the automobile battery according to the charging mode selected by the user, and detecting data such as charging voltage, current, temperature and the like. The charging amount CAN be calculated, inquired and displayed in the charging process, data storage is carried out locally, and data are transmitted to cloud EMS management through the CAN and the Ethernet. In addition, when delay or power grid voltage fluctuation exists in cloud deployment, the local control system can realize energy local management, and the output of the energy storage module and the photovoltaic module is regulated and controlled, so that the charging voltage reaches the required standard.
The AC/DC load comprises box electricity utilization units such as a touch screen module, a consumption document printing module, a voice module, a monitoring module and the like. The direct current load and the direct current bus directly obtain electricity, the alternating current module inputs the alternating current voltage of 530V, the direct current voltage + 750-1500V is output through the inverter, the rated power of the rectifying section is 100kW, and the rectifying section is connected to the direct current bus.
The high-voltage overcharge module can realize the maximum output voltage of 1500V and the maximum charging current of 600A.
2 high-voltage direct-hanging charging pile topology and working principle
Aiming at the voltage sag and drop problems frequently occurring in a direct current micro-grid, the high-voltage direct-hanging charging pile provided by the embodiment is suitable for ultrahigh-power high-voltage direct-hanging charging, and can complete ultrahigh-power high-voltage direct-hanging charging with lower cost, an isolated high-frequency direct-alternating-direct structure is adopted in a topology, and the topology mainly comprises an energy storage unit, an inversion unit, a filtering part, a high-frequency transformer, a dynamic voltage regulation unit, a control unit and the like, and is shown in fig. 1. The system has the following working principle that firstly, the system generates an instruction signal according to the detected load voltage information, then calculates the required compensation voltage according to the load voltage requirement, controls the output of the inverter, the output of the inverter is subjected to filtering, boosting by a high-frequency transformer and rectification by a dynamic voltage adjusting unit, and finally the output voltage and the system power voltage are superposed to supply to the load so as to stabilize the voltage required by the load.
The topological medium-high frequency transformer increases the voltage compensation range, realizes input and output electrical isolation and improves the safety of the whole system; in addition, the high-frequency LC filtering (passive filtering) structure ensures that the output current is continuous and smooth, the high-frequency structure reduces the volume of equipment, and the application range of the unidirectional high-voltage direct-hanging charging pile is enlarged. The bypass switch in the structure plays a protective role, for example, when a load or a system is in short circuit, the switch is closed to protect the unidirectional high-voltage direct-hanging charging pile, and the filter capacitor of the rectifier is C 2 Connected in parallel with the bypass switch; or the unidirectional high-voltage direct-hanging charging pile can be disconnected when the unidirectional high-voltage direct-hanging charging pile fails.
2.1 DC energy storage unit
The main function of the energy storage unit in the high-voltage direct-hanging charging pile structure is to provide energy, when a voltage drop occurs to a power grid, the high-voltage direct-hanging charging pile starts a dynamic voltage compensation function, active power is injected into the power grid system, and the energy is provided for the power grid. The energy storage unit of high-voltage direct-hanging charging pile generally has two structural forms: one is that there is independent energy storage medium, namely use the energy storage component directly, the voltage output is stable, can effective compensating voltage; the other type of the high-voltage direct-hanging charging pile does not contain an independent medium, the rectifying circuit is used for obtaining compensation energy from an alternating current power grid, but the control algorithm is complex, and when a main network fails or electric energy contains harmonics, the quality of the compensation voltage output by the high-voltage direct-hanging charging pile is directly influenced.
The first energy storage structure is adopted, and a large number of common energy storage media such as superconducting energy storage, flywheel energy storage, super capacitors, storage battery energy storage and the like exist in a direct-current microgrid. The energy storage device balances the use benefits, selects the storage battery as the energy storage element, is a relatively mature energy storage unit in the currently used energy storage equipment, and has low manufacturing cost, less maintenance and high reliability. When the storage battery is used as a direct current energy storage unit, the energy flow is completely controllable, the high-voltage direct-hanging charging pile has good static characteristics, more stable compensation voltage is output, and the electric energy quality of the microgrid is effectively improved.
2.2 high frequency inverter Unit
Because storage battery voltage is lower, can't satisfy load side direct current voltage requirement, this paper adopts the high frequency contravariant unit, adds DC AC contravariant unit in the energy storage unit side, and with the direct current contravariant to high frequency alternating current, and then steps up through high frequency transformer, promotes the voltage compensation scope that one-way high pressure directly hung electric pile. The inversion unit is an important component unit of the DC dynamic voltage regulator, when a load has a voltage drop problem, the unidirectional high-voltage direct-hanging charging pile starts the controller to operate a voltage compensation algorithm to generate a compensation command voltage, and the inversion unit outputs the required compensation voltage according to the generated command voltage.
The inverter adopts the full-bridge structure commonly used, adopts the high frequency design on this basis moreover, has reduced the electric capacity and the inductance value of system component, has reduced the whole volume of filling electric pile equipment, and the cost is reduced improves economic nature. And the high-frequency structure is favorable for frequency adjustment of the inversion output voltage and elimination of higher harmonics. The modulation of the inverter circuit adopts bipolar PWM wave pulse width modulation, the modulation wave is a sine wave, the carrier wave is a triangular wave, the two waves are compared to generate switching value, and the on-off of a switching tube of the inverter is controlled. The direct current is inverted to alternating current. When the full bridge outputs, two switches are simultaneously conducted at the same time. For example, in the positive modulation mode, the T4 tube is always in a conducting state, and the T1 tube is controlled to be conducted by the modulation signal; similarly, under the condition of negative polarity, the T3 tube is always in a conducting state, and the modulation signal controls the T2 to be conducted.
2.3 Filter Unit
The performance of the filter is mainly judged by harmonic suppression capability, and can be observed by a THD value. In addition, it is desirable to minimize the additional current stress of the filter to the inverter, the magnitude of the additional current stress being related to the losses of the devices and lines, and the capacity of the power components. The filtering part in the unidirectional high-voltage direct-hanging charging pile adopts a normal K-type gamma low-pass filter which is mainly used for removing switching frequency and harmonic waves of frequency bands near the switching frequency. The filter unit is composed of an inductor L in figure 1 1 ，L 2 And a capacitor C 1 And (4) forming.
2.4 boost Unit
High frequency is a research hotspot of the current power electronic technology. Compared with a power frequency transformer, the high-frequency transformer greatly reduces the sectional area of the magnetic core, reduces the volume space, and has the advantages of small loss, high conversion efficiency, wide voltage stabilizing range and the like. This topic adopts high frequency transformer to replace the power frequency transformer that traditional interchange high pressure directly hung electric pile adopted, reduces the volume that one-way high pressure directly hung electric pile filled, alleviates one-way high pressure directly hung electric pile's weight simultaneously, improves one-way high pressure and directly hangs electric pile's work efficiency and reliability. The high-frequency transformer is one of core devices of the unidirectional high-voltage direct-hanging charging pile, performs electromagnetic conversion on output voltage subjected to inversion and filtering, outputs required voltage, electrically isolates the unidirectional high-voltage direct-hanging charging pile from a main network, protects the high-voltage direct-hanging charging pile, and plays roles in energy conversion, voltage conversion, insulation and isolation and the like.
3 example of System operation
A750V-1500V direct current bus is arranged in the 10kV direct-hanging multifunctional complementary charging box body and is connected with a 10kV power grid through a converter with a direct current voltage adjusting function. The direct current bus is connected with the 1500V high-voltage super charging port, the energy storage module and the alternating current and direct current power utilization unit, and the DC/DC converter, the energy storage converter and the like are arranged in the box body to meet the power utilization requirements of each circuit.
The cloud EMS system allocates unit energy in a whole mode, data processing such as power consumption, pricing and user fee deduction is carried out on the cloud, and the data are fed back to the local data display screen. The local control system controls the output power of the super charging port and the monitoring of the power consumption condition according to the charging mode selected by a user, and simultaneously allocates the start, the stop and the output of the photovoltaic and energy storage modules of the box body.
During the power consumption valley period, the super charging port can supply power to the automobile battery according to the maximum output power. At the moment, the energy storage module enters a charging state, and the SOC is maintained in an interval of 60% -80%; the photovoltaic module can work in the state of being stopped or started, when photovoltaic power generation is carried out, local power utilization is partially provided, and surplus electric quantity can be fed to a power grid.
In the electricity utilization peak period, the number of the vehicles participating in charging is large, in order to ensure that the charging power and efficiency of each path are constant, the monitoring module feeds back the voltage level of the direct current bus to the local control system, and the control system sends out an instruction to start the photovoltaic module and the energy storage module. The energy storage module enters a discharging state, and meanwhile, the photovoltaic module responds to the electricity demand with the maximum output force, so that the voltage of the bus is constant.
For the ultra-high power charging pile with low cost, the power distribution network outputs a voltage bus u dc =900V and u dc =1500V and the output current is I in The operation modes in two voltage fluctuation states are simulated by taking =100A as an example. If the charging rated charging voltage of the electric automobile is 1200V, the rated charging power is 120kW dc When =900V, as shown in fig. 2, the dynamic voltage adjustment unit outputs a voltage Δ u =310V, the inductance divides the voltage by 10V, the electric vehicle charging pile outputs a 1200V dc voltage, and at this time, the energy storage unit absorbs power Δ u × I through the high-frequency transformer in ＝31kW；u dc When =1500V, as shown in fig. 3, the dynamic voltage adjustment unit outputs a voltage with positive left and negative right Δ u =290V, the inductive voltage division is 10V, the electric vehicle charging pile outputs a direct current voltage of 1200V, and the energy storage unit supplements power to Δ u × I through the high-frequency transformer at this time in =29kW. Thereby passing dynamic electricityThe voltage adjusting unit can meet the charging requirements of different types of electric vehicles on different rated charging voltages, the energy storage unit can respectively absorb and supplement energy under two conditions, the exchange power is far smaller than the charging power, and the effect of charging with ultrahigh power through the low-power charging module is achieved. This fill electric pile can provide maximum power and reach 1200kW, and exchange power level is about 300kW, can satisfy many electric automobile demands of charging simultaneously.
Example two
As shown in fig. 4, this embodiment provides a control method for a high-voltage direct-hanging charging pile, where the control method is applied to the high-voltage direct-hanging charging pile according to the first embodiment, and the control method includes:
step 401: acquiring the output voltage of the power distribution network;
step 402: when the difference value between the output voltage of the power distribution network and the rated input voltage of the direct current charging pile is not zero, controlling the energy storage unit to output direct current voltage, and controlling the inversion unit to invert the direct current voltage into alternating current voltage;
step 403: filtering the alternating voltage;
step 404: performing frequency boosting and voltage boosting treatment on the alternating-current voltage after the filtering treatment;
step 405: and adjusting the direction of the AC voltage subjected to the frequency and voltage boosting treatment according to the positive and negative of the difference value to obtain a compensation voltage, and after the compensation voltage is superposed with the output voltage of the power distribution network, transmitting the superposed voltage to the DC charging pile.
For example, step 405 includes: when the difference value is larger than zero, the direction of the compensation voltage is opposite to the direction of the output voltage of the power distribution network, and the energy storage unit absorbs power through the high-frequency transformer; when the difference value is less than zero, the direction of the compensation voltage is determined to be the same as the direction of the output voltage of the power distribution network, and the energy storage unit provides power through the high-frequency transformer.
The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. For the system disclosed by the embodiment, the description is relatively simple because the system corresponds to the method disclosed by the embodiment, and the relevant points can be referred to the method part for description.
The principles and embodiments of the present invention have been described herein using specific examples, which are provided only to help understand the method and the core concept of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the foregoing, the description is not to be taken in a limiting sense.
Claims (9)
1. The utility model provides a high pressure is directly hung and is filled electric pile which characterized in that includes:
the control unit, and the energy storage unit, the inversion unit, the filtering unit, the high-frequency transformer and the dynamic voltage regulation unit which are connected in sequence;
the dynamic voltage regulating unit is also respectively connected with the power distribution network and the direct current charging pile;
the control unit is respectively connected with the inversion unit, the power distribution network and the energy storage unit;
the control unit is used for controlling the energy storage unit to output direct-current voltage and controlling the inversion unit to invert the direct-current voltage into alternating-current voltage when the difference value between the output voltage of the power distribution network and the rated input voltage of the direct-current charging pile is not zero;
the filtering unit is used for filtering the alternating voltage;
the high-frequency transformer is used for performing frequency-boosting and voltage-boosting treatment on the filtered alternating-current voltage;
and the dynamic voltage adjusting unit is used for adjusting the direction of the alternating-current voltage subjected to the frequency-boosting and voltage-boosting treatment according to the positive and negative of the difference value to obtain a compensation voltage, and transmitting the superposed voltage to the direct-current charging pile after superposing the compensation voltage and the output voltage of the power distribution network.
2. The high-voltage direct-hanging charging pile according to claim 1, wherein the inverter unit specifically comprises:
the first full-bridge inverter structure and the first capacitor;
the first capacitor is connected with the energy storage unit;
the first full-bridge inversion structure comprises two parallel half-bridge structures; each half-bridge structure comprises two bridge arms connected in series; each bridge arm comprises a switching device and a diode which are connected in parallel;
two public ends obtained by connecting two half-bridge structures in parallel in a first full-bridge inversion structure are respectively connected with two ends of the first capacitor;
the public ends of two bridge arms in the first full-bridge inversion structure are respectively connected with a filtering unit; and the common ends of the bridge arms are the common ends of two bridge arms in the same half-bridge structure.
3. The high-voltage direct-hanging charging pile according to claim 2, wherein the filtering unit specifically comprises:
a first inductor, a second inductor and a second capacitor;
the first end of the first inductor and the first end of the second inductor are respectively connected with the common ends of two bridge arms in the first full-bridge inversion structure;
the second end of the first inductor and the second end of the second inductor are respectively connected with two ends of the second capacitor;
and two ends of the second capacitor are respectively connected with two ends of the primary side of the high-frequency transformer.
4. The low-cost ultrahigh-power high-voltage direct-hanging charging pile according to claim 1, wherein the energy storage unit is a storage battery.
5. The high-voltage direct-hanging charging pile according to claim 3, wherein the dynamic voltage regulation unit specifically comprises:
a second full-bridge inverter structure and a third capacitor;
the second full-bridge inversion structure has the same structure as the first full-bridge inversion structure;
two public ends obtained by connecting two half-bridge structures in parallel in the second full-bridge inversion structure are respectively connected with the power distribution network and the direct current charging pile;
two public ends obtained by connecting two half-bridge structures in parallel in the second full-bridge inverter structure are also respectively connected with two ends of the third capacitor;
and the public ends of two bridge arms in the second full-bridge inversion structure are respectively connected with the two ends of the secondary side of the high-frequency transformer.
6. The high-voltage direct-hanging charging pile according to claim 5, wherein the dynamic voltage regulation unit further comprises:
a bypass switch;
the bypass switch is connected in parallel with the third capacitor.
7. The high-voltage direct-hanging charging pile according to claim 1, further comprising:
a third inductor;
the third inductor is arranged between the dynamic voltage regulating unit and the direct current charging pile.
8. A control method of a high-voltage direct-hanging charging pile, which is applied to the high-voltage direct-hanging charging pile according to any one of claims 1 to 7, the control method comprising:
acquiring the output voltage of the power distribution network;
when the difference value between the output voltage of the power distribution network and the rated input voltage of the direct current charging pile is not zero, controlling the energy storage unit to output direct current voltage, and controlling the inversion unit to invert the direct current voltage into alternating current voltage;
filtering the alternating voltage;
performing frequency boosting and voltage boosting treatment on the alternating-current voltage after the filtering treatment;
and adjusting the direction of the alternating-current voltage subjected to the frequency-boosting and voltage-boosting treatment according to the positive and negative of the difference value to obtain a compensation voltage, and after the compensation voltage is superposed with the output voltage of the power distribution network, transmitting the superposed voltage to the direct-current charging pile.
9. The method for controlling the high-voltage direct-hanging charging pile according to claim 8, wherein the direction of the alternating-current voltage subjected to the frequency-boosting and voltage-boosting treatment is adjusted according to the positive and negative of the difference value to obtain the compensation voltage, and the method specifically comprises the following steps:
when the difference value is larger than zero, determining that the direction of the compensation voltage is opposite to the direction of the output voltage of the power distribution network;
and when the difference value is less than zero, determining that the direction of the compensation voltage is the same as the direction of the output voltage of the power distribution network.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211531477.3A CN115940227A (en) | 2022-12-01 | 2022-12-01 | High-voltage direct-hanging charging pile and control method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211531477.3A CN115940227A (en) | 2022-12-01 | 2022-12-01 | High-voltage direct-hanging charging pile and control method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115940227A true CN115940227A (en) | 2023-04-07 |
Family
ID=86549917
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211531477.3A Pending CN115940227A (en) | 2022-12-01 | 2022-12-01 | High-voltage direct-hanging charging pile and control method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115940227A (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003289625A (en) * | 2002-03-28 | 2003-10-10 | Mitsubishi Electric Corp | Voltage fluctuation compensating apparatus |
| EP1619781A1 (en) * | 2004-07-21 | 2006-01-25 | ThyssenKrupp Aufzugswerke GmbH | Circuitry for a converter |
| CN106451410A (en) * | 2016-11-16 | 2017-02-22 | 上海交通大学 | Direct current dynamic voltage restorer and restoring method |
| CN107154631A (en) * | 2017-05-22 | 2017-09-12 | 上海电力学院 | Dynamic voltage regulation device and adjusting method based on modular multilevel inverter |
-
2022
- 2022-12-01 CN CN202211531477.3A patent/CN115940227A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003289625A (en) * | 2002-03-28 | 2003-10-10 | Mitsubishi Electric Corp | Voltage fluctuation compensating apparatus |
| EP1619781A1 (en) * | 2004-07-21 | 2006-01-25 | ThyssenKrupp Aufzugswerke GmbH | Circuitry for a converter |
| CN106451410A (en) * | 2016-11-16 | 2017-02-22 | 上海交通大学 | Direct current dynamic voltage restorer and restoring method |
| CN107154631A (en) * | 2017-05-22 | 2017-09-12 | 上海电力学院 | Dynamic voltage regulation device and adjusting method based on modular multilevel inverter |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110601248B (en) | Multi-mode coordination control method of annular alternating current-direct current hybrid micro-grid system | |
| CN104362656B (en) | A kind of control method stabilizing microgrid power swing based on hybrid energy-storing VSI | |
| CN203358382U (en) | Bidirectional-interaction electrified railway high-voltage direct-current traction power supply system based on new energy | |
| CN105048453B (en) | A kind of electric power spring topology and its control method | |
| CN102160014A (en) | Power converting apparatus | |
| CN103023344B (en) | A kind of general intelligent grid power electronic equipment | |
| CN103647302A (en) | Multi-sub microgrid-contained mixed microgrid system and control method thereof | |
| CN103448573A (en) | High-voltage direct-current tractive power supply system of bidirectional interactive electrified railway | |
| CN103595063A (en) | Energy storage converter and battery energy storage system of energy storage converter | |
| CN105811453A (en) | Distributed energy intelligent access system and access method thereof | |
| CN112072716A (en) | Power distribution network terminal electric energy router and control method thereof | |
| Cheng et al. | A smart charging algorithm based on a fast charging station without energy storage system | |
| CN103490448A (en) | Power generation energy storage device based on cascade H bridge and multiport DC converter | |
| CN102916435B (en) | A kind of battery energy storage power conversion system containing Z source network and control method thereof | |
| CN203027153U (en) | Universal smart power grid power electronic device | |
| CN103915856A (en) | Base station grid connected-charging photovoltaic micro-inverter system and control method thereof | |
| CN114123268A (en) | Concentrated conversion high-frequency boosting thermal power energy storage system | |
| CN102122833B (en) | Power supply method of non-master/slave self-current-sharing grid-connected parallel uninterrupted power supply system | |
| CN108347067A (en) | A kind of microgrid framework and control method containing battery energy storage and generator | |
| CN103532162B (en) | Based on the topological structure and the starting method that control the Hybrid HVDC system switched | |
| CN205407292U (en) | Distributing type energy intelligence access system | |
| CN106849103A (en) | Transformerless type single-phase dynamic voltage compensator based on HVDC Modulation | |
| CN203574386U (en) | Multilevel multiport power generation and energy storage hybrid apparatus | |
| CN202309538U (en) | Standard converting device of electric automobile and distributed power source | |
| CN112436739B (en) | Modular combined direct-current transformer and control method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |