CN111146932A - DC-DC electric energy transmission system - Google Patents

DC-DC electric energy transmission system Download PDF

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Publication number
CN111146932A
CN111146932A CN201911220324.5A CN201911220324A CN111146932A CN 111146932 A CN111146932 A CN 111146932A CN 201911220324 A CN201911220324 A CN 201911220324A CN 111146932 A CN111146932 A CN 111146932A
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China
Prior art keywords
port
direct current
power
converter
positive electrode
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Pending
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CN201911220324.5A
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Chinese (zh)
Inventor
文劲宇
肖遥遥
胡伟
沈煜
王文烁
左文平
周猛
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Huazhong University of Science and Technology
Electric Power Research Institute of State Grid Hubei Electric Power Co Ltd
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Huazhong University of Science and Technology
Electric Power Research Institute of State Grid Hubei Electric Power Co Ltd
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Application filed by Huazhong University of Science and Technology, Electric Power Research Institute of State Grid Hubei Electric Power Co Ltd filed Critical Huazhong University of Science and Technology
Priority to CN201911220324.5A priority Critical patent/CN111146932A/en
Publication of CN111146932A publication Critical patent/CN111146932A/en
Pending legal-status Critical Current

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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/32—Means for protecting converters other than automatic disconnection
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
    • H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
    • H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
    • H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
    • H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/33569—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements
    • H02M3/33576—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements having at least one active switching element at the secondary side of an isolation transformer
    • H02M3/33584—Bidirectional converters
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/0067—Converter structures employing plural converter units, other than for parallel operation of the units on a single load
    • H02M1/0074—Plural converter units whose inputs are connected in series
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/32—Means for protecting converters other than automatic disconnection
    • H02M1/325—Means for protecting converters other than automatic disconnection with means for allowing continuous operation despite a fault, i.e. fault tolerant converters

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Dc-Dc Converters (AREA)

Abstract

The invention discloses a DC-DC electric energy transmission system, which comprises a first DC port, a second DC port, a DC-DC power converter and a unidirectional semiconductor switch, wherein the first DC port is connected with the first DC port; the positive electrode and the negative electrode of the first direct current port are respectively connected with the positive electrode and the negative electrode of the direct current input port of the power converter and are respectively externally connected with a power supply direct current system; the positive electrode and the negative electrode of the second direct current port are respectively externally connected with a power receiving direct current system, wherein the positive electrode is connected with the positive electrode of the direct current output port of the power converter and the negative electrode of the unidirectional semiconductor switch, and the negative electrode is connected with the negative electrode of the first direct current port; the positive electrode of the unidirectional semiconductor switch is connected with the negative electrode of the direct-current output port of the power converter, and the positive electrode of the first direct-current port is connected with the positive electrode of the unidirectional semiconductor switch. According to the invention, the unidirectional semiconductor switch is reversely connected in parallel between the positive electrode and the negative electrode of the direct-current output port of the power converter, the positive electrode of the input end of the power converter is connected to the positive electrode of the unidirectional semiconductor switch, and when the power converter fails due to a fault, the unidirectional semiconductor switch is used for recovering the electric energy transmission, so that the reliability of an electric energy transmission system is improved, and the cost is greatly reduced.

Description

DC-DC electric energy transmission system
Technical Field
The invention belongs to the field of power transmission, and particularly relates to a DC-DC power transmission system.
Background
With the development of distributed power generation technology and direct current power distribution technology, the demand for a renewable energy power generation system to be directly incorporated into a direct current power distribution network via a DC-DC power transmission system is increasing. In a low-voltage and small-capacity DC-DC electric energy transmission system, basic DC-DC converters such as a boost converter and a buck-boost converter are the preferred technical scheme, but when the technical scheme is applied to a medium-high-voltage and large-capacity scene, the problems of high technical difficulty and high cost are faced, and the limitation is large. In the field of medium-high voltage large-capacity DC-DC power transmission, a great deal of attention and research is paid to DC-DC converter technical schemes represented by a direct current autotransformer, a direct current transformer constructed based on a Double Active Bridge (DAB) power unit, and the like.
The 109600049a patent discloses a solid-state dc transformer that is used to transfer power, where the transferred power needs to be converted twice, i.e., the dc power is first converted into ac power, and then the ac power is further converted into dc power. Because the number of times of electric energy conversion is large, large electric energy loss is brought. When the direct current solid-state transformer is applied to medium and high voltage occasions, the defects of large number of power unit modules, complex system and high cost exist. In addition, when the direct current solid-state transformer fails, an energy transmission channel between different direct current systems on the high-voltage side and the low-voltage side of the direct current solid-state transformer is interrupted, and the reliability of energy transmission is reduced. Patent 201410024869.X provides a three-dimensional direct current-direct current converter for interconnecting two direct current systems with different voltage levels, and its internal VSC converter unit adopts a three-phase voltage source converter structure. In the middle-high voltage application, patent 201410024869.X can solve the defects of large number of power unit modules, complex system, high cost and high loss existing in patent 109600049 a. However, when the VSC converter unit in patent 201410024869.X fails due to a fault, the three-dimensional dc-dc converter loses the power transmission capability, and there is also a problem of reliability of power transmission.
Therefore, for the disclosed DC-DC converter (such as the aforementioned boost converter, DC solid-state transformer, stereo DC-DC converter, etc.): on one hand, when the DC-DC converter fails due to a fault, an energy transmission channel between the direct current systems on both sides of the DC-DC converter is interrupted, so that the reliability of the technical scheme needs to be further improved; on the other hand, when some of the prior disclosed technical solutions are applied to medium and high voltage occasions, the problems of technical difficulty, large number of high-power unit modules, large capacity, complex system and high cost exist.
Disclosure of Invention
The invention provides a DC-DC electric energy transmission system, which is used for solving the technical problem of high electric energy transmission cost caused by electric energy transmission interruption when a DC-DC converter fails to transmit electric energy in the conventional electric energy transmission system.
The technical scheme for solving the technical problems is as follows: a DC-DC power transmission system comprises a first DC port, a second DC port, a DC-DC power converter and a unidirectional semiconductor switch;
the positive electrode and the negative electrode of the first direct current port are respectively connected with the positive electrode and the negative electrode of the direct current input port of the DC-DC power converter and are respectively externally connected with the positive port and the negative port of a power supply direct current system;
the positive electrode and the negative electrode of the second direct current port are respectively externally connected with a positive port and a negative port of a power receiving direct current system, wherein the positive electrode is also connected with the positive electrode of a direct current output port of the DC-DC power converter and the negative electrode of the unidirectional semiconductor switch, and the negative electrode is also connected with the negative electrode of the first direct current port;
the positive electrode of the unidirectional semiconductor switch is connected with the negative electrode of the direct current output port of the DC-DC power converter, and the positive electrode of the first direct current port is also connected with the positive electrode of the unidirectional semiconductor switch.
The invention has the beneficial effects that: according to the invention, the unidirectional semiconductor switch is reversely connected in parallel between the positive electrode and the negative electrode of the direct current output port of the DC-DC power converter, and the positive electrode of the input end of the DC-DC power converter is connected to the positive electrode of the unidirectional semiconductor switch, so that when the DC-DC power converter in the DC-DC power transmission system fails due to a fault, the power transmission between the power supply direct current system and the power receiving direct current system is automatically recovered through the unidirectional semiconductor switch, the zero response time characteristic is achieved, the interruption of the power transmission between the power supply direct current system and the power receiving direct current system is avoided, and the reliability and the availability of the DC-DC power transmission system are greatly improved. In addition, the positive electrode of the input end of the DC-DC power converter is connected to the negative electrode of the output end of the DC-DC power converter, and the negative electrode of the input end of the DC-DC power converter is further connected to the negative electrode of the second direct current port, so that the design capacity and the electric energy loss of the DC-DC power converter can be reduced, the size and the cost of the DC-DC power converter are further reduced, and the economy of the DC-DC electric energy transmission system is greatly improved.
On the basis of the technical scheme, the invention can be further improved as follows.
Further, the number of the DC-DC power converters is n, and n is a positive integer; when n is larger than 1, n DC-DC power converters are connected in combination, and the anode of the DC input port of one DC-DC power converter is connected with the anode of the first DC port; the negative electrode of the direct current input port of one DC-DC power converter is connected with the negative electrode of the first direct current port; the positive electrode of the direct current output port of one DC-DC power converter is connected with the positive electrode of the second direct current port, and the negative electrode of the direct current output port of one DC-DC power converter is connected with the positive electrode of the unidirectional semiconductor switch.
Further, when n is larger than 1, the direct current input ports of the n DC-DC power converters are respectively connected with the first direct current port in a parallel connection mode; and the direct current output ports of the n DC-DC power converters are respectively connected with the anode of the second direct current port and the anode of the unidirectional semiconductor switch in a parallel connection mode.
The invention has the further beneficial effects that: the overall current transmission capability of the DC-DC power converter part is increased by respectively connecting the input ports and the output ports of the plurality of DC-DC power converters in parallel, so that the purpose of improving the power transmission capability is achieved.
Further, when n is larger than 1, the direct current input ports of the n DC-DC power converters are respectively connected with the first direct current port in a parallel connection mode; the direct current output ports of the n DC-DC power converters are connected in series, the positive electrode of the direct current output port of one DC-DC power converter is connected with the positive electrode of the second direct current port, and the negative electrode of the direct current output port of one DC-DC power converter is connected with the positive electrode of the unidirectional semiconductor switch.
The invention has the further beneficial effects that: the input end of each DC-DC power converter is connected in parallel to increase the integral current tolerance of the input port of the DC-DC power converter, and the output end of each DC-DC power converter is connected in series to increase the integral voltage tolerance of the output port of the DC-DC power converter, so that the aim of improving the integral power transmission capability of the DC-DC power converter is fulfilled.
Further, when n is greater than 1, the direct current input ports of the n DC-DC power converters are connected in series, wherein the anode of the direct current input port of one DC-DC power converter is connected with the anode of the first direct current port, and the cathode of the direct current input port of one DC-DC power converter is connected with the cathode of the second direct current port; the direct current output ports of the n DC-DC power converters are connected in series, the positive electrode of the direct current output port of one DC-DC power converter is connected with the positive electrode of the second direct current port, and the negative electrode of the direct current output port of one DC-DC power converter is connected with the positive electrode of the unidirectional semiconductor switch.
The invention has the further beneficial effects that: the input end and the output end of each DC-DC power converter are respectively connected in series, so that the overall voltage tolerance of the input port and the output port of the DC-DC power converter can be improved, and the purpose of improving the power transmission capability of the DC-DC power converter is achieved.
Further, when n is greater than 1, the direct current input ports of the n DC-DC power converters are connected in series, wherein the anode of the direct current input port of one DC-DC power converter is connected with the anode of the first direct current port, and the cathode of the direct current input port of one DC-DC power converter is connected with the cathode of the second direct current port; and the direct current output ports of the n DC-DC power converters are connected in parallel and are respectively connected with the anode of the second direct current port and the anode of the unidirectional semiconductor switch.
The invention has the further beneficial effects that: the input ends of the DC-DC power converters are connected in series, so that the integral voltage tolerance of the input ports of the DC-DC power converter part can be improved, and the output ports of the DC-DC power converters are connected in parallel, so that the integral current tolerance of the output ports of the DC-DC power converter part can be improved, and the integral power transmission capability of the DC-DC power converter part is greatly improved.
Further, the n DC-DC power converters have the same topology.
The invention has the further beneficial effects that: the manufacturing difficulty of the n DC-DC power converters can be simplified.
Further, the n DC-DC power converters are each independently selected from:
the converter comprises a DC-DC power converter based on a double active bridge, a bidirectional LLC resonant converter, a bidirectional LLC converter added with auxiliary inductance, a bidirectional LLC converter added with auxiliary capacitance, a resonant converter based on the double active bridge, a resonant converter based on a half bridge, a BOOST converter, a BUCK-BOOST converter and a bidirectional half bridge converter.
The invention has the further beneficial effects that: the application field of the DC-DC electric energy transmission system is expanded.
Further, the unidirectional semiconductor switch is a diode valve bank.
The invention has the further beneficial effects that: the diode valve group can enable the electric energy transmission branch circuit with the failed DC-DC power converter to have better active switching-on and switching-off capacity, and the controllability of the branch circuit is improved.
Drawings
FIG. 1 is a schematic diagram of a prior art DC-DC converter;
fig. 2 is a schematic diagram of a DC-DC power transmission system according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of a low-cost and highly reliable DC-DC power transmission system according to an embodiment of the present invention;
fig. 4 is a specific schematic diagram of another low-cost high-reliability DC-DC power transmission system provided by the embodiment of the invention;
fig. 5 is a specific schematic diagram of another low-cost high-reliability DC-DC power transmission system provided by an embodiment of the present invention;
fig. 6 is a specific schematic diagram of another low-cost high-reliability DC-DC power transmission system provided by an embodiment of the present invention;
fig. 7 is a specific schematic diagram of another low-cost high-reliability DC-DC power transmission system provided by the embodiment of the invention;
FIG. 8 is a schematic diagram of a bi-directional LLC resonant converter;
FIG. 9 is a schematic diagram of a bidirectional LLC converter with added auxiliary inductance;
FIG. 10 is a schematic diagram of a bidirectional LLC converter with added auxiliary capacitance;
FIG. 11 is a schematic diagram of a bidirectional full-bridge LLC converter;
FIG. 12 is a schematic diagram of a bi-directional half-bridge LLC resonant converter;
fig. 13 is a schematic diagram of a bidirectional half-bridge converter.
The same reference numbers will be used throughout the drawings to refer to the same or like elements or structures, wherein: 1. a power supply direct current system 2, a power receiving direct current system 3, a double-active-bridge inverter 31, an inverter bridge 32, a rectifier bridge 4, an electric energy transmission system 40, a first direct current port 41, a second direct current port 42, a DC-DC power converter 43 and a unidirectional semiconductor switch.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.
As shown in fig. 1, there is a specific schematic diagram of a DC-DC power converter 3 for transmitting electric energy between a supplying DC system 1 and a receiving DC system 2. When the electric energy of the power supply DC system 1 is transmitted to the power receiving DC system 2, the electric energy is first converted into the electric energy in the form of high-frequency ac through the inverter bridge 31 inside the DC-DC power converter 3, and then converted into the electric energy in the form of DC through the rectifier bridge 32 inside the DC-DC power converter 3. It can be seen that the electric energy transmission process needs to be subjected to two-stage DC-ac-DC conversion, and the capacity design of the inverter unit 31 and the rectifier unit 32 needs to be designed according to the actual transmission capacity, so that the capacity requirement of the power electronic devices inside the DC-DC power converter is large. On the other hand, when the DC-DC power converter 3 fails due to a fault, the transmission of electric energy between the power supply DC system 1 and the power receiving DC system 2 is interrupted, and energy cannot be continuously transmitted.
As shown in fig. 2, the present embodiment provides a DC-DC power transmission system 4, which includes a first DC port 40, a second DC port 41, a DC-DC power converter 42, and a unidirectional semiconductor switch 43. The positive electrode and the negative electrode of the first direct current port are respectively connected with the positive electrode and the negative electrode of a direct current input port of the DC-DC power converter and are respectively externally connected with a positive port and a negative port of a power supply direct current system; the positive electrode and the negative electrode of the second direct current port are respectively externally connected with a positive port and a negative port of the power receiving direct current system, wherein the positive electrode is also connected with the positive electrode of the direct current output port of the DC-DC power converter and the negative electrode of the unidirectional semiconductor switch, and the negative electrode is also connected with the negative electrode of the first direct current port; the positive pole of the unidirectional semiconductor switch is connected with the negative pole of the direct current output port of the DC-DC power converter, and the positive pole of the first direct current port is also connected with the positive pole of the unidirectional semiconductor switch.
It should be noted that the unidirectional semiconductor switch is a semiconductor switch device with both limited on and current flowing directions, and the device is turned on only when the voltage level direction meets the closing requirement, and further the current flowing direction is limited, for example, diode valve bank, semi-controlled semiconductor device (such as thyristor), fully-controlled semiconductor device (such as insulated gate bipolar transistor IGBT), etc. are all unidirectional semiconductor switches, wherein, for example, the anode of the diode valve bank is the anode of the unidirectional semiconductor switch, and the cathode of the diode valve bank is the cathode of the unidirectional semiconductor switch.
The unidirectional semiconductor switch is reversely connected in parallel between the positive pole and the negative pole of the direct current output port of the DC-DC power converter, and the positive pole of the input end of the DC-DC power converter is connected to the positive pole of the unidirectional semiconductor switch, so that when the DC-DC power converter in the DC-DC power transmission system fails due to faults, the power transmission between the power supply direct current system and the power receiving direct current system is automatically recovered through the unidirectional semiconductor switch, the zero response time characteristic is achieved, the interruption of the power transmission between the power supply direct current system and the power receiving direct current system is avoided, and the reliability and the availability of the DC-DC power transmission system are greatly improved. In addition, the positive electrode of the input end of the DC-DC power converter is connected to the negative electrode of the output end of the DC-DC power converter, and the negative electrode of the input end of the DC-DC power converter is further connected to the negative electrode of the second direct current port, so that the design capacity and the electric energy loss of the DC-DC power converter can be reduced, the size and the cost of the DC-DC power converter are further reduced, and the economy of the DC-DC electric energy transmission system is greatly improved.
For example, as shown in fig. 3, the DC-DC power converter includes a first DC port 40, a second DC port 41, and a DC-DC power converter 42, and the unidirectional semiconductor switch 43 is a diode valve group 43. The first direct current port 40 is connected to the power supply direct current system 1, the positive pole of the first direct current port 40 is connected to the positive pole of the power supply direct current system 1, and the negative pole of the first direct current port 40 is connected to the negative pole of the power supply direct current system 1; the second dc port 41 is connected to the powered dc system 2, and the anode of the second dc port 41 is connected to the anode of the powered dc system 2, and the cathode of the second dc port 41 is connected to the cathode of the powered dc system 2; the first DC port 40 is further connected to a DC input port of the DC-DC power converter 42, and an anode of the first DC port 40 is connected to an anode of the DC input port of the DC-DC power converter 42, and a cathode of the first DC port 40 is connected to a cathode of the DC input port of the DC-DC power converter 42; the anode of the second direct current port 41 is further connected to the anode of the direct current output port of the DC-DC power converter 42, and the cathode of the second direct current port 41 is further connected to the cathode of the direct current input port of the DC-DC power converter 42; the positive electrode of the DC input port of the DC-DC power converter 42 is connected to the negative electrode of the DC output port of the DC-DC power converter 42; the diode bank 43 is connected across the positive pole and the negative pole of the direct current output port of the DC-DC power converter 42, the anode of the diode bank 43 is connected to the negative pole of the direct current output port of the DC-DC power converter 42, and the cathode of the diode bank 43 is connected to the positive pole of the direct current output port of the DC-DC power converter 42.
When the DC-DC power converter 42 works normally, the electric energy transmitted from the positive electrode of the first DC port enters the positive electrode of the DC input port of the DC-DC power converter 42 and flows into the negative electrode of the first DC port from the negative electrode of the DC input port of the DC-DC power converter 42, the electric energy is converted by the DC-DC power converter 42, then is output from the positive electrode of the DC output port of the DC-DC power converter 42 and flows into the positive electrode of the second DC port to supply power to the power receiving DC system, and at this time, the power receiving DC system forms a power supply loop through the negative electrode of the second DC port and the negative electrode of the first DC port. In this case, no current flows through the current branch from the positive terminal of the first DC port to the negative terminal of the DC output port of the DC-DC power converter 42 due to the limited current flow through the diode bank.
When the DC-DC power converter 42 fails or is actively locked, the electric energy transmitted from the positive electrode of the first DC port directly enters the negative electrode of the DC output port of the DC-DC power converter 42 and supplies power to the powered DC system through the diode valve bank. The electric energy transmission branch circuit after the failure of the DC-DC power converter has the capability of actively switching on and switching off, and the controllability of the branch circuit is improved.
Preferably, the number of the DC-DC power converters is n, and n is a positive integer; when n is larger than 1, the n DC-DC power converters are connected in a combined mode, and the anode of the direct current input port of one DC-DC power converter is connected with the anode of the first direct current port; the negative electrode of the direct current input port of one DC-DC power converter is connected with the negative electrode of the first direct current port; the positive electrode of the direct current output port of one DC-DC power converter is connected with the positive electrode of the second direct current port, and the negative electrode of the direct current output port of the one DC-DC power converter is connected with the anode of the diode valve bank.
The number of the DC-DC power converters is not limited, and when a plurality of power converters exist, the power converters can be connected according to various different connection modes, so long as one input end positive and negative terminal port and one output end positive and negative terminal port are respectively connected, the compatibility of the electric energy transmission system to the DC-DC power converters is greatly improved.
Preferably, when n > 1, as shown in fig. 4, the DC input ports of the n DC-DC power converters are connected in parallel to the first DC port respectively; the direct current output ports of the n DC-DC power converters are respectively connected with the anode of the second direct current port and the anode of the diode valve bank in a parallel connection mode.
The overall current transmission capability of the DC-DC power converter part is increased by respectively connecting the input ports and the output ports of the plurality of DC-DC power converters in parallel, so that the purpose of improving the power transmission capability is achieved.
Preferably, when n > 1, as shown in fig. 5, the DC input ports of the n DC-DC power converters are connected in parallel to the first DC port respectively; the direct current output ports of the n DC-DC power converters are connected in series, the anode of the direct current output port of one DC-DC power converter is connected with the anode of the second direct current port, and the cathode of the direct current output port of one DC-DC power converter is connected with the anode of the diode valve bank.
The input end of each DC-DC power converter is connected in parallel to increase the integral current tolerance of the input port of the DC-DC power converter, and the output end of each DC-DC power converter is connected in series to increase the integral voltage tolerance of the output port of the DC-DC power converter, so that the aim of improving the integral power transmission capability of the DC-DC power converter is fulfilled.
Preferably, when n > 1, as shown in fig. 6, the DC input ports of the n DC-DC power converters are connected in series, wherein the positive electrode of the DC input port of one DC-DC power converter is connected to the positive electrode of the first DC port, and the negative electrode of the DC input port of one DC-DC power converter is connected to the negative electrode of the second DC port; the direct current output ports of the n DC-DC power converters are connected in series, the anode of the direct current output port of one DC-DC power converter is connected with the anode of the second direct current port, and the cathode of the direct current output port of one DC-DC power converter is connected with the anode of the diode valve bank.
The input end and the output end of each DC-DC power converter are respectively connected in series, so that the overall voltage tolerance of the input port and the output port of the DC-DC power converter can be improved, and the purpose of improving the power transmission capability of the DC-DC power converter is achieved.
Preferably, when n > 1, as shown in fig. 7, the DC input ports of the n DC-DC power converters are connected in series, wherein the positive electrode of the DC input port of one DC-DC power converter is connected to the positive electrode of the first DC port, and the negative electrode of the DC input port of one DC-DC power converter is connected to the negative electrode of the second DC port; the direct current output ports of the n DC-DC power converters are connected in parallel and are respectively connected with the positive electrode of the second direct current port and the anode of the diode valve bank.
The input ends of the DC-DC power converters are connected in series, so that the integral voltage tolerance of the input ports of the DC-DC power converter part can be improved, and the output ports of the DC-DC power converters are connected in parallel, so that the integral current tolerance of the output ports of the DC-DC power converter part can be improved, and the integral power transmission capability of the DC-DC power converter part is greatly improved.
Preferably, the n DC-DC power converters have the same topology.
Preferably, the n DC-DC power converters are independently selected from:
the converter comprises a DC-DC power converter based on a Double Active Bridge (DAB), a bidirectional LLC resonant converter, a bidirectional LLC converter, a resonant converter, a BOOST converter, a BUCK-BOOST converter and a bidirectional half-bridge converter, wherein the bidirectional LLC converter is added with an auxiliary inductor, the bidirectional LLC converter is added with an auxiliary capacitor, the resonant converter is based on the Double Active Bridge (DAB), the resonant converter is based on a half bridge, the.
Circuits are known in the art, for example, wherein a bidirectional LLC resonant converter is shown in fig. 8, a bidirectional LLC converter with an auxiliary inductor is shown in fig. 9, a bidirectional LLC converter with an auxiliary capacitor is shown in fig. 10, a bidirectional full-bridge LLC converter is shown in fig. 11, a bidirectional half-bridge LLC resonant converter is shown in fig. 12, and a bidirectional half-bridge converter is shown in fig. 13.
It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims (9)

1. A DC-DC power transmission system is characterized by comprising a first direct current port, a second direct current port, a DC-DC power converter and a unidirectional semiconductor switch;
the positive electrode and the negative electrode of the first direct current port are respectively connected with the positive electrode and the negative electrode of the direct current input port of the DC-DC power converter and are respectively externally connected with the positive port and the negative port of a power supply direct current system;
the positive electrode and the negative electrode of the second direct current port are respectively externally connected with a positive port and a negative port of a power receiving direct current system, wherein the positive electrode is also connected with the positive electrode of a direct current output port of the DC-DC power converter and the negative electrode of the unidirectional semiconductor switch, and the negative electrode is also connected with the negative electrode of the first direct current port;
the positive electrode of the unidirectional semiconductor switch is connected with the negative electrode of the direct current output port of the DC-DC power converter, and the positive electrode of the first direct current port is also connected with the positive electrode of the unidirectional semiconductor switch.
2. A DC-DC power transmission system according to claim 1 wherein the number of DC-DC power converters is n, n being a positive integer; when n is larger than 1, n DC-DC power converters are connected in combination, and the anode of the DC input port of one DC-DC power converter is connected with the anode of the first DC port; the negative electrode of the direct current input port of one DC-DC power converter is connected with the negative electrode of the first direct current port; the positive electrode of the direct current output port of one DC-DC power converter is connected with the positive electrode of the second direct current port, and the negative electrode of the direct current output port of one DC-DC power converter is connected with the positive electrode of the unidirectional semiconductor switch.
3. A DC-DC power transmission system according to claim 2, wherein when n > 1, the DC input ports of the n DC-DC power converters are connected in parallel with the first DC port respectively; and the direct current output ports of the n DC-DC power converters are respectively connected with the anode of the second direct current port and the anode of the unidirectional semiconductor switch in a parallel connection mode.
4. A DC-DC power transmission system according to claim 2, wherein when n > 1, the DC input ports of the n DC-DC power converters are connected in parallel with the first DC port respectively; the direct current output ports of the n DC-DC power converters are connected in series, the positive electrode of the direct current output port of one DC-DC power converter is connected with the positive electrode of the second direct current port, and the negative electrode of the direct current output port of one DC-DC power converter is connected with the positive electrode of the unidirectional semiconductor switch.
5. A DC-DC power transmission system according to claim 2, wherein when n > 1, the DC input ports of the n DC-DC power converters are connected in series, wherein the positive pole of the DC input port of one DC-DC power converter is connected to the positive pole of the first DC port, and the negative pole of the DC input port of one DC-DC power converter is connected to the negative pole of the second DC port; the direct current output ports of the n DC-DC power converters are connected in series, the positive electrode of the direct current output port of one DC-DC power converter is connected with the positive electrode of the second direct current port, and the negative electrode of the direct current output port of one DC-DC power converter is connected with the positive electrode of the unidirectional semiconductor switch.
6. A DC-DC power transmission system according to claim 2, wherein when n > 1, the DC input ports of the n DC-DC power converters are connected in series, wherein the positive pole of the DC input port of one DC-DC power converter is connected to the positive pole of the first DC port, and the negative pole of the DC input port of one DC-DC power converter is connected to the negative pole of the second DC port; and the direct current output ports of the n DC-DC power converters are connected in parallel and are respectively connected with the anode of the second direct current port and the anode of the unidirectional semiconductor switch.
7. A DC-DC power transmission system according to any of claims 2 to 6, wherein the n DC-DC power converters have the same topology.
8. A DC-DC electrical energy transfer system according to any one of claims 2 to 6, wherein the n DC-DC power converters are each independently selected from:
the converter comprises a DC-DC power converter based on a double active bridge, a bidirectional LLC resonant converter, a bidirectional LLC converter added with auxiliary inductance, a bidirectional LLC converter added with auxiliary capacitance, a resonant converter based on the double active bridge, a resonant converter based on a half bridge, a BOOST converter, a BUCK-BOOST converter and a bidirectional half bridge converter.
9. A DC-DC power transmission system according to any of claims 1 to 6, wherein the unidirectional semiconductor switches are diode banks.
CN201911220324.5A 2019-12-03 2019-12-03 DC-DC electric energy transmission system Pending CN111146932A (en)

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Application Number Priority Date Filing Date Title
CN201911220324.5A CN111146932A (en) 2019-12-03 2019-12-03 DC-DC electric energy transmission system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201911220324.5A CN111146932A (en) 2019-12-03 2019-12-03 DC-DC electric energy transmission system

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CN111146932A true CN111146932A (en) 2020-05-12

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112366795A (en) * 2020-12-01 2021-02-12 上海交通大学 Power electronic intelligent battery unit

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112366795A (en) * 2020-12-01 2021-02-12 上海交通大学 Power electronic intelligent battery unit
CN112366795B (en) * 2020-12-01 2022-12-09 上海交通大学 Power electronic intelligent battery unit

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