CN113364334B - Double-parallel Buck-Boost inverter and control method thereof - Google Patents

Double-parallel Buck-Boost inverter and control method thereof Download PDF

Info

Publication number
CN113364334B
CN113364334B CN202110796745.3A CN202110796745A CN113364334B CN 113364334 B CN113364334 B CN 113364334B CN 202110796745 A CN202110796745 A CN 202110796745A CN 113364334 B CN113364334 B CN 113364334B
Authority
CN
China
Prior art keywords
unit
conduction device
switch unit
unidirectional conduction
energy storage
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.)
Active
Application number
CN202110796745.3A
Other languages
Chinese (zh)
Other versions
CN113364334A (en
Inventor
许颇
谢伟杰
王一鸣
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Ginlong Technologies Co Ltd
Original Assignee
Ginlong Technologies Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Ginlong Technologies Co Ltd filed Critical Ginlong Technologies Co Ltd
Priority to CN202110796745.3A priority Critical patent/CN113364334B/en
Publication of CN113364334A publication Critical patent/CN113364334A/en
Application granted granted Critical
Publication of CN113364334B publication Critical patent/CN113364334B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • 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
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/66—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output with possibility of reversal
    • H02M7/68—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output with possibility of reversal by static converters
    • H02M7/72—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output with possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M7/79—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output with possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M7/81—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output with possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal arranged for operation in parallel
    • 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
    • H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
    • H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
    • H02M3/10—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M3/145—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M3/155—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/156—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators
    • H02M3/158—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators including plural semiconductor devices as final control devices for a single load
    • H02M3/1584—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators including plural semiconductor devices as final control devices for a single load with a plurality of power processing stages connected in parallel

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Inverter Devices (AREA)

Abstract

The invention discloses a double parallel Buck-Boost inverter, which comprises a direct current side port, a first staggered chopping unit, a first switch unit, a second staggered chopping unit, a second switch unit and an alternating current side port, wherein the first staggered chopping unit comprises a third switch unit, a fourth switch unit, a first unidirectional conduction device, a second unidirectional conduction device, a first energy storage element and a second energy storage element, and the second staggered chopping unit has the same structure as the first chopping unit; the third switch unit, the first unidirectional conduction device, the second unidirectional conduction device and the fourth switch unit which are reversely connected are sequentially connected, the third switch unit and the fourth switch unit are connected with the positive electrode of the direct current side port, and the positive electrodes of the first unidirectional conduction device and the second unidirectional conduction device are respectively connected with the negative electrode of the direct current side port through the first switch unit; the first energy storage element and the second energy storage element are respectively and correspondingly connected with the cathodes of the first unidirectional conduction device and the second unidirectional conduction device so as to improve conversion efficiency.

Description

Double-parallel Buck-Boost inverter and control method thereof
Technical Field
The invention relates to the technical field of inverters, in particular to a double-parallel Buck-Boost inverter and a control method thereof.
Background
An inverter is a converter that converts a voltage or current of a direct current input into a voltage or current of an alternating current output, and is widely used in new energy power generation systems, electric power drive systems, ac uninterruptible power supplies, induction heating, active power filters, static var compensators, and the like.
The topology of a conventional Voltage-source inverter (VSI) is shown in fig. 1. The 4 switching tubes of the bridge arm are connected in anti-parallel with the diodes, so that the bridge arm has bidirectional current flow and unidirectional voltage blocking capability. The defects are that: on the one hand, the conventional Voltage Source Inverter (VSI) belongs to a buck converter, and outputs an alternating current lower than the direct current bus voltage. Therefore, for power conversion situations where the input DC voltage is low and a high ac voltage needs to be output, such as a new energy power generation system, an additional DC-DC boost converter needs to be added to the front stage of the inverter bridge to boost the bus voltage to be greater than the ac output voltage to output the desired ac voltage. The added primary power converter increases the cost of the system and reduces conversion efficiency and reliability. On the other hand, the switching tubes of the same bridge arm of the conventional voltage source inverter cannot be conducted simultaneously, otherwise, a through short circuit can occur to damage the switching devices, so that the converter cannot work reliably. To prevent the bridge arm from being directly connected, a method of inserting a dead zone is generally adopted, but the dead zone time causes the increase of output harmonic voltage and the complexity of control.
Disclosure of Invention
In order to solve the technical defects, the technical scheme adopted by the invention is that the double-parallel Buck-Boost inverter comprises a direct current side port, a first staggered chopping unit, a first switching unit, a second staggered chopping unit, a second switching unit and an alternating current side port, wherein the first staggered chopping unit comprises a third switching unit, a fourth switching unit, a first unidirectional conduction device, a second unidirectional conduction device, a first energy storage element and a second energy storage element, and the second staggered chopping unit comprises a fifth switching unit, a sixth switching unit, a third unidirectional conduction device, a fourth unidirectional conduction device, a third energy storage element and a fourth energy storage element.
The first end part of the third switch unit, the first end part of the fourth switch unit and the first end part of the fifth switch unit are respectively electrically connected with the positive electrode of the direct current side port, the positive electrode of the first unidirectional conduction device and the positive electrode of the second unidirectional conduction device are respectively electrically connected with the negative electrode of the direct current side port through the first switch unit, the positive electrode of the third unidirectional conduction device and the positive electrode of the fourth unidirectional conduction device are respectively electrically connected with the negative electrode of the direct current side port through the second switch unit, and the first end part of the first switch unit and the first end part of the second switch unit are respectively electrically connected with the two ends of the alternating current side port.
The first end of the first energy storage element, the first end of the second energy storage element, the first end of the third energy storage element and the first end of the fourth energy storage element are respectively and electrically connected with the negative electrode of the first unidirectional conduction device, the negative electrode of the second unidirectional conduction device, the negative electrode of the third unidirectional conduction device and the negative electrode of the fourth unidirectional conduction device in a one-to-one correspondence manner, and the second end of the first energy storage element, the second end of the second energy storage element, the second end of the third energy storage element and the second end of the fourth energy storage element are respectively and electrically connected with the negative electrode of the direct current side port and the junction of the first switch unit.
Further, the first switch unit, the second switch unit, the third switch unit, the fourth switch unit, the fifth switch unit and the sixth switch unit are bidirectional controllable switch elements, or two unidirectional controllable switch elements which are connected in parallel in an anti-direction and are not provided with body diodes, or two unidirectional controllable switch elements which are connected in series in an anti-direction and are provided with body diodes.
Further, the first unidirectional conduction device, the second unidirectional conduction device, the third unidirectional conduction device and the fourth unidirectional conduction device are diodes or switching tubes.
Further, the first energy storage element, the second energy storage element, the third energy storage element and the fourth energy storage element are inductors.
Further, a direct current power supply is arranged at the direct current side port, an alternating current side filter unit and an alternating current side load are arranged at the alternating current side port in parallel, two ends of the alternating current side filter unit are respectively and electrically connected with the first end part of the first switch unit and the first end part of the second switch unit, and at the moment, the double parallel Buck-Boost inverter works in an inversion mode.
Further, the direct current side port is provided with a direct current side filtering unit and a direct current side load which are arranged in parallel, the alternating current side port is provided with an alternating current power supply and an alternating current side filtering unit which is connected in parallel with two ends of the alternating current power supply, a first end part of the direct current side filtering unit is electrically connected with a third switching unit, a fourth switching unit, a fifth switching unit and a sixth switching unit, a second end part of the direct current side filtering unit is electrically connected with a second end part of a first inductor, two ends of the alternating current side filtering unit are respectively electrically connected with a first end part of the first switching unit and a first end part of the second switching unit, and the double parallel Buck-Boost inverter works in a rectifying mode.
Further, the alternating current side filtering unit and the direct current side filtering unit are filtering capacitors or LC circuits or LCL circuits.
The invention also provides a control method of the double parallel Buck-Boost inverter, which is suitable for controlling the double parallel Buck-Boost inverter and comprises the following steps:
Applying a drive signal with a phase difference of 180 degrees to a third switch unit and a fourth switch unit in the first staggered chopping unit, and applying a drive signal with a phase difference of 180 degrees to a fifth switch unit and a sixth switch unit in the second staggered chopping unit;
In one power frequency period, the first staggered chopping unit and the second staggered chopping unit alternately work in respective half periods;
The on-state of the first switch unit and the second switch unit is changed by controlling the on-duty ratio of the third switch unit, the fourth switch unit, the fifth switch unit and the sixth switch unit, and the direct current side or the alternating current side is charged, so that the output alternating current voltage is higher or lower than the direct current bus voltage.
Further, the double parallel Buck-Boost inverter comprises the following 8 working modes in a power frequency period:
1) Inversion mode a: in the positive half period of the alternating current side, the second staggered chopping unit works, and the third switching unit, the fourth switching unit, the second switching unit, the first unidirectional conduction device, the second unidirectional conduction device, the third unidirectional conduction device and the fourth unidirectional conduction device are disconnected; the fifth switch unit and the sixth switch unit are sequentially conducted and have a time interval of 180 DEG phase angle; the first switch unit is turned on or turned off, the direct current side charges and stores energy to the third energy storage element and the fourth energy storage element through the fifth switch unit and the sixth switch unit, and the alternating current side load is powered by the alternating current side filter unit;
2) Inversion mode b: in the positive half cycle of the alternating current side, the second staggered chopping unit works, and the third switching unit, the fourth switching unit, the fifth switching unit, the sixth switching unit, the second switching unit, the first unidirectional conduction device and the second unidirectional conduction device are disconnected; the first switch unit, the third unidirectional conduction device and the fourth unidirectional conduction device are conducted; the energy in the third energy storage element and the fourth energy storage element is supplied to the alternating current side through the first switch unit, the third unidirectional conduction device and the fourth unidirectional conduction device;
3) Inversion mode c: in the negative half cycle of the alternating current side, the first staggered chopping unit works, and the fifth switching unit, the sixth switching unit, the first unidirectional conduction device, the second unidirectional conduction device, the third unidirectional conduction device and the fourth unidirectional conduction device are disconnected; the third switch unit and the fourth switch unit are sequentially conducted and the time interval is 180 DEG phase angle; the second switch unit is turned on or turned off, the direct current side charges and stores energy to the first energy storage element and the second energy storage element through the third switch unit and the fourth switch unit, and the alternating current side load is powered by the alternating current side filter unit;
4) Inversion mode d: in the negative half cycle of the alternating current side, the first staggered chopping unit works, and the third switching unit, the fourth switching unit, the fifth switching unit, the sixth switching unit, the first switching unit, the third unidirectional conduction device and the fourth unidirectional conduction device are disconnected; the second switch unit, the first unidirectional conduction device and the second unidirectional conduction device are conducted; the energy in the first energy storage element and the second energy storage element is supplied to the alternating current side through the second switch unit, the first unidirectional conduction device and the second unidirectional conduction device;
5) Rectification mode a: in the positive half cycle of the alternating current side, the first staggered chopping unit works, and the third switching unit, the fourth switching unit, the fifth switching unit, the sixth switching unit, the first switching unit, the third unidirectional conduction device and the fourth unidirectional conduction device are disconnected; the second switch unit, the first unidirectional conduction device and the second unidirectional conduction device are conducted; the alternating current side charges and stores energy to the first energy storage element and the second energy storage element through the second switch unit, the first unidirectional conduction device and the second unidirectional conduction device, and the direct current side load is powered by the direct current side filter unit;
6) Rectification mode b: in the positive half cycle of the alternating current side, the first staggered chopping unit works, and the fifth switching unit, the sixth switching unit, the first switching unit, the second switching unit, the first unidirectional conduction device, the second unidirectional conduction device, the third unidirectional conduction device and the fourth unidirectional conduction device are disconnected; the third switch unit and the fourth switch unit are sequentially conducted and the time interval is 180 DEG phase angle; the energy in the first energy storage element and the second energy storage element is supplied to the direct-current side load through the third switch unit and the fourth switch unit, and meanwhile, the direct-current side filter unit is charged with energy for energy storage;
7) Rectification mode c: in the negative half cycle of the alternating current side, the second staggered chopping unit works, and the third switching unit, the fourth switching unit, the fifth switching unit, the sixth switching unit, the second switching unit, the first unidirectional conduction device and the second unidirectional conduction device are disconnected; the first switch unit, the third unidirectional conduction device and the fourth unidirectional conduction device are conducted; the alternating current side charges and stores energy to the third energy storage element and the fourth energy storage element through the first switch unit, the third unidirectional conduction device and the fourth unidirectional conduction device, and the direct current side load is powered by the direct current side filter unit;
8) Rectification mode d: in the negative half cycle of the alternating current side, the second staggered chopping unit works, and the third switching unit, the fourth switching unit, the first switching unit, the second switching unit, the first unidirectional conduction device, the second unidirectional conduction device, the third unidirectional conduction device and the fourth unidirectional conduction device are disconnected; the fifth switch unit and the sixth switch unit are sequentially conducted and have a time interval of 180 DEG phase angle; the energy in the third energy storage element and the fourth energy storage element is supplied to the direct-current side load through the fifth switch unit and the sixth switch unit, and meanwhile the direct-current side filter unit is charged with energy for energy storage.
Compared with the prior art, the technical scheme of the invention has the beneficial effects that:
According to the double-parallel Buck-Boost inverter and the control method thereof, provided by the invention, the Boost or Buck conversion of the inverter is realized by arranging two groups of Buck-Boost circuits which are in staggered parallel connection, and any two switch units on the staggered chopper units are free from direct connection possibility through the reverse blocking effect of a unidirectional conduction device, so that the double-parallel Buck-Boost inverter can be conducted simultaneously, and after an inductor is buffered in the charging and discharging process, the danger of direct connection of a bridge arm is avoided, the problems of output harmonic voltage increase and complex control caused by dead time insertion are further solved, and the bidirectional flow of energy is realized; by alternately operating the two staggered chopping units in one power frequency period, the switching frequency and the conversion efficiency are improved; and under the same output inductance current ripple, only smaller inductance is needed, and meanwhile, the current stress and loss of the high-frequency switch tube can be reduced; an extra DC-DC boost converter is not needed to be added at the front stage of the inverter bridge, so that the cost of the system is reduced, the complexity of a circuit is reduced, and the reliability of conversion is improved.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a schematic circuit diagram of a conventional bridge inverter;
FIG. 2 (a) is a schematic circuit diagram of a double parallel Buck-Boost inverter according to an embodiment of the present invention;
FIG. 2 (b) is a schematic circuit diagram of a double parallel Buck-Boost inverter in an inversion mode according to an embodiment of the present invention;
FIG. 2 (c) is a schematic circuit diagram of a double parallel Buck-Boost inverter in a rectifying mode according to an embodiment of the present invention;
fig. 3 is an embodiment 1 of each switching unit provided in the embodiment of the present invention;
Fig. 4 is an embodiment 2 of each switching unit provided in the embodiment of the present invention;
Fig. 5 is an embodiment 3 of each switching unit provided in the embodiment of the present invention;
Fig. 6-9 are schematic circuit diagrams of 4 working modes of the double parallel Buck-Boost inverter in an inversion mode according to the embodiment of the invention;
Fig. 10-13 are schematic circuit diagrams of 4 working modes of the double parallel Buck-Boost inverter in a rectifying mode according to the embodiment of the invention;
Fig. 14 (a) is a timing chart of a control method of a double parallel Buck-Boost inverter in an inversion mode according to an embodiment of the present invention;
FIG. 14 (b) is a timing chart of each switching cycle in the inversion mode in a control method of a double parallel Buck-Boost inverter according to an embodiment of the present invention;
fig. 14 (c) is a table of correspondence between the on states of each switch unit and corresponding modes in an inversion mode in the control method of the double parallel Buck-Boost inverter provided by the embodiment of the invention;
FIG. 15 (a) is a timing chart of each switching cycle in the rectification mode in a control method of a double parallel Buck-Boost inverter according to an embodiment of the present invention;
fig. 15 (b) is a table of correspondence between the on states of each switch unit and corresponding modes in the rectification mode in the control method of the double parallel Buck-Boost inverter according to the embodiment of the present invention.
Detailed Description
The invention will be further described with reference to the drawings and the specific examples.
Example 1
Referring to fig. 2a, the dual parallel Buck-Boost inverter provided by the present invention includes a dc side port a, a first interleaved chopper unit, a first switch unit S 1, a second interleaved chopper unit, a second switch unit S 2, and an ac side port B, wherein the first interleaved chopper unit includes a third switch unit S a, a fourth switch unit S b, a first unidirectional conductive device, a second unidirectional conductive device, a first energy storage element, and a second energy storage element, and the second interleaved chopper unit includes a fifth switch unit S c, a sixth switch unit S d, a third unidirectional conductive device, a fourth unidirectional conductive device, a third energy storage element, and a fourth energy storage element.
The third switch unit S a, the first unidirectional conducting device, the second unidirectional conducting device and the fourth switch unit S b which are reversely connected are sequentially connected to form a first loop, the fifth switch unit S c, the third unidirectional conducting device, the fourth unidirectional conducting device and the sixth switch unit S d which are reversely connected are sequentially connected to form a second loop, the first end of the third switch unit S a, the first end of the fourth switch unit S b, the first end of the fifth switch unit S c and the first end of the sixth switch unit S d are respectively and electrically connected with the positive electrode of the direct current side port a, the positive electrode of the first unidirectional conducting device and the positive electrode of the second unidirectional conducting device are respectively and electrically connected with the negative electrode of the direct current side port a through the first switch unit S 1, the positive electrode of the third unidirectional conducting device and the positive electrode of the fourth unidirectional conducting device are respectively and electrically connected with the negative electrode of the direct current side port a through the second switch unit S 2, and the first end of the first switch unit S 1 and the first end of the second switch unit S 2 are respectively and electrically connected with the two ends of the direct current side port B.
The first end of the first energy storage element, the first end of the second energy storage element, the first end of the third energy storage element and the first end of the fourth energy storage element are respectively and correspondingly and electrically connected with the negative electrode of the first unidirectional conduction device, the negative electrode of the second unidirectional conduction device, the negative electrode of the third unidirectional conduction device and the negative electrode of the fourth unidirectional conduction device, and the second end of the first energy storage element, the second end of the second energy storage element, the second end of the third energy storage element and the second end of the fourth energy storage element are respectively and electrically connected with the negative electrode of the direct current side port A and the junction of the first switch unit S 1.
Preferably, the first switch unit S 1, the second switch unit S 2, the third switch unit S a, the fourth switch unit S b, the fifth switch unit S c, and the sixth switch unit S d are bidirectional controllable switch elements, or two unidirectional controllable switch elements which are antiparallel and without body diodes, or two unidirectional controllable switch elements which are antiparallel and with body diodes.
The controllable switching element is specifically a self-controlled forward conduction device, such as an insulated gate bipolar transistor (Insulated Gate Bipolar Transistor, IGBT), a Metal-Oxide-semiconductor field effect transistor (MOSFET), etc.
The first switch unit S 1, the second switch unit S 2, the third switch unit S a, the fourth switch unit S b, the fifth switch unit S c, and the sixth switch unit S d may be the same or different in type, so long as a bidirectional controllable function can be achieved.
The unidirectional controllable switching element shown in fig. 3 is a two anti-parallel, power-on unidirectional flow controllable switching element.
The unidirectional controllable switching elements shown in fig. 4, 5 are two reverse series connected, power-on unidirectional flowing controllable switching elements with body diodes.
Preferably, the first unidirectional conduction device, the second unidirectional conduction device, the third unidirectional conduction device and the fourth unidirectional conduction device are diodes or switching tubes. Specifically, diodes, for convenience of description of the corresponding figures, are sequentially set as a first diode D a, a second diode D b, a third diode D c, and a fourth diode D d.
Preferably, the first energy storage element, the second energy storage element, the third energy storage element and the fourth energy storage element are inductors. For convenience of description of the corresponding diagrams, the first inductance L a, the second inductance L b, the third inductance L c, and the fourth inductance L d are specifically set.
As shown in fig. 2B, the dc side port a is provided with a dc power supply V bus, the ac side port B is provided with an ac side filter unit and an ac side load connected in parallel, and both ends of the ac side filter unit are electrically connected to the first end of the first switch unit S 1 and the first end of the second switch unit S 2, respectively, at this time, the double parallel Buck-Boost inverter operates in an inversion mode.
As shown in fig. 2c, the dc side port a is provided with a dc side filtering unit and a dc side load connected in parallel, the ac side port B is provided with an ac power source V g and ac side filtering units connected in parallel to both ends of the ac power source V g, a first end of the dc side filtering unit is electrically connected to the third switching unit S a, the fourth switching unit S b, the fifth switching unit S c and the sixth switching unit S d, a second end of the dc side filtering unit is electrically connected to a second end of the first inductor L a, and both ends of the ac side filtering unit are respectively electrically connected to a first end of the first switching unit S 1 and a first end of the second switching unit S 2, and the dual parallel Buck-Boost inverter operates in rectification.
Preferably, the ac side filter unit and the dc side filter unit are filter capacitors or LC circuits or LCL circuits. Specifically, the filter capacitor is set as an ac side filter capacitor C f and a dc side filter capacitor C bus in order to facilitate description of the corresponding diagrams. The direct current power supply V bus can be obtained by rectifying and filtering the input of a power grid or an alternating current motor, and can also be obtained by a photovoltaic cell, a fuel cell or a storage battery. The ac side load and the dc side load are load resistors, and are set as a load R L1、RL2 in order to facilitate description of the corresponding diagram.
The chopping part is composed of 4 identical Buck-Boost chopper circuits: the third switch unit S a, the first diode D a and the first inductor L a form a Buck-Boost1; the fourth switch unit S b, the second diode D b and the second inductor L b form a Buck-Boost2; the fifth switch unit S c, the third diode D c and the third inductor L c form a Buck-Boost3; the sixth switching unit S d, the fourth diode D d and the fourth inductor L d form a Buck-Boost4. The third switch unit S a and the fourth switch unit S b of the Buck-Boost1 and the Buck-Boost2 are 180 degrees different in trigger signal to form a first staggered chopping unit; the triggering signals of the fifth switching unit S c and the sixth switching unit S d of the Buck-Boost3 and the Buck-Boost4 are different by 180 degrees to form a second staggered chopping unit. In one power frequency period, the first interleaving chopper unit and the second interleaving unit alternately work in each half period.
The first switch unit S 1 and the second switch unit S 2 form a directional part, and related to the voltage direction of alternating current measurement, the on states of the first switch unit S 1 and the second switch unit S 2 are changed by adjusting the duty ratios of the third switch unit S a, the fourth switch unit S b, the fifth switch unit S c and the sixth switch unit S d, so that the output alternating current is higher or lower than the direct current bus voltage.
In fig. 2 (a), 2 (b), 2 (c), and 6-13, the first switching unit S 1, the second switching unit S 2, the third switching unit S a, the fourth switching unit S b, the fifth switching unit S c, and the sixth switching unit S d are illustrated as only one ideal switch.
The invention provides a control method of a double-parallel Buck-Boost inverter, which is suitable for controlling the double-parallel Buck-Boost inverter and comprises the following steps:
the third switching unit S a and the fourth switching unit S b in the first interleaved chopper unit are supplied with drive signals having a phase difference of 180 degrees, and the fifth switching unit S c and the sixth switching unit S d in the second interleaved chopper unit are supplied with drive signals having a phase difference of 180 degrees.
In one power frequency period, the first staggered chopping unit and the second staggered chopping unit alternately work in respective half periods;
By controlling the on duty ratio of the third switch unit S a, the fourth switch unit S b, the fifth switch unit S c, and the sixth switch unit S d, the on state of the first switch unit S 1 and the second switch unit S 2 is changed, and the dc side or the ac side is charged, so that the output ac voltage is higher or lower than the dc bus voltage.
When the direct current side is charged, the alternating current power V g is supplied, and when the alternating current side is charged, the direct current power V bus is supplied to change the current direction of the first switch unit S 1 and the second switch unit S 2.
Preferably, the double parallel Buck-Boost inverter comprises the following 8 working modes in one power frequency period:
1) Inversion mode a: in the positive half period of the alternating current side, the second staggered chopping unit works, and the third switching unit S a, the fourth switching unit S b, the second switching unit S 2, the first unidirectional conduction device, the second unidirectional conduction device, the third unidirectional conduction device and the fourth unidirectional conduction device are disconnected; the fifth switch unit S c and the sixth switch unit S d are sequentially conducted and have a time interval of 180 DEG phase angle; the first switch unit S 1 is turned on or off, the direct current side charges and stores energy to the third energy storage element and the fourth energy storage element through the fifth switch unit S c and the sixth switch unit S d, and the alternating current side load is powered by the alternating current side filtering unit. To reduce the losses, the first switching unit S 1 is here turned on.
2) Inversion mode b: in the positive half period of the alternating current side, the second staggered chopping unit works, and the third switching unit S a, the fourth switching unit S b, the fifth switching unit S c, the sixth switching unit S d, the second switching unit S 2, the first unidirectional conduction device and the second unidirectional conduction device are disconnected; the first switch unit S 1, the third unidirectional conduction device and the fourth unidirectional conduction device are conducted; the energy in the third energy storage element and the fourth energy storage element is supplied to the alternating current side through the first switch unit S 1, the third unidirectional conduction device and the fourth unidirectional conduction device.
3) Inversion mode c: in the negative half cycle of the alternating current side, the first staggered chopping unit works, and the fifth switching unit S c, the sixth switching unit S d, the first switching unit S 1, the first unidirectional conduction device, the second unidirectional conduction device, the third unidirectional conduction device and the fourth unidirectional conduction device are disconnected; the third switch unit S a and the fourth switch unit S b are sequentially conducted and have a time interval of 180 DEG phase angle; the second switch unit S 2 is turned on or off, the direct current side charges and stores energy to the first energy storage element and the second energy storage element through the third switch unit S a and the fourth switch unit S b, and the alternating current side load is powered by the alternating current side filtering unit. In order to reduce the losses, the second switching unit S 2 is here turned on.
4) Inversion mode d: in the negative half cycle of the alternating current side, the first staggered chopping unit works, and the third switching unit S a, the fourth switching unit S b, the fifth switching unit S c, the sixth switching unit S d, the first switching unit S 1, the third unidirectional conduction device and the fourth unidirectional conduction device are disconnected; the second switch unit S 2, the first unidirectional conduction device and the second unidirectional conduction device are conducted; the energy in the first energy storage element and the second energy storage element is supplied to the alternating current side through the second switch unit S 2, the first unidirectional conduction device and the second unidirectional conduction device;
5) Rectification mode a: in the positive half period of the alternating current side, the first staggered chopping unit works, and the third switching unit S a, the fourth switching unit S b, the fifth switching unit S c, the sixth switching unit S d, the first switching unit S 1, the third unidirectional conduction device and the fourth unidirectional conduction device are disconnected; the second switch unit S 2, the first unidirectional conduction device and the second unidirectional conduction device are conducted; the alternating current side charges and stores energy to the first energy storage element and the second energy storage element through the second switch unit S 2, the first unidirectional conduction device and the second unidirectional conduction device, and the direct current side load is powered by the direct current side filter unit.
6) Rectification mode b: in the positive half cycle of the alternating current side, the first staggered chopping unit works, and the fifth switching unit S c, the sixth switching unit S d, the first switching unit S 1, the second switching unit S 2, the first unidirectional conduction device, the second unidirectional conduction device, the third unidirectional conduction device and the fourth unidirectional conduction device are disconnected; the third switch unit S a and the fourth switch unit S b are sequentially conducted and have a time interval of 180 DEG phase angle; the energy in the first energy storage element and the second energy storage element is supplied to the direct-current side load through the third switch unit S a and the fourth switch unit S b, and meanwhile the direct-current side filter unit is charged with energy for energy storage.
7) Rectification mode c: in the negative half cycle of the alternating current side, the second staggered chopping unit works, and the third switching unit S a, the fourth switching unit S b, the fifth switching unit S c, the sixth switching unit S d, the second switching unit S 2, the first unidirectional conduction device and the second unidirectional conduction device are disconnected; the first switch unit S 1, the third unidirectional conduction device and the fourth unidirectional conduction device are conducted; the alternating current side charges and stores energy to the third energy storage element and the fourth energy storage element through the first switch unit S 1, the third unidirectional conduction device and the fourth unidirectional conduction device, and the direct current side load is powered by the direct current side filter unit.
8) Rectification mode d: in the negative half cycle of the alternating current side, the second staggered chopping unit works, and the third switching unit S a, the fourth switching unit S b, the first switching unit S 1, the second switching unit S 2, the first unidirectional conduction device, the second unidirectional conduction device, the third unidirectional conduction device and the fourth unidirectional conduction device are disconnected; the fifth switch unit S c and the sixth switch unit S d are sequentially conducted and have a time interval of 180 DEG phase angle; the energy in the third energy storage element and the fourth energy storage element is supplied to the direct-current side load through the fifth switch unit S c and the sixth switch unit S d, and meanwhile the direct-current side filter unit is charged with energy for energy storage.
From the above, in the inversion mode, the circuit mode can be divided into 4 modes according to the operation conditions of the first interleaved chopping unit and the second interleaved chopping unit, and fig. 6 to 9 are equivalent circuits of the 4 modes in the inversion mode. The corresponding relationship between the on state of each switch unit and the corresponding mode is shown in fig. 14 c.
In the view of figure 14c,、/>、/>、/>、/>、/>Representing that the corresponding switch is in an on state,/>、/>、/>、/>、/>、/>The mode marked as "\" and the unlisted mode represent that the corresponding switch is in the off state and the mode is an invalid mode.
When the circuit works in the inversion mode, the alternating current side can output voltages with different polarities (positive and negative) by controlling the conduction states of the first switch unit S1 and the second switch unit S2. The second switching unit S2 is not operated in the ac side positive half cycle, and the first switching unit S1 is not operated in the ac side negative half cycle.
From the above, in the rectifying mode, the circuit mode can be divided into 4 modes according to the operation conditions of the first interleaved chopping unit and the second interleaved chopping unit, and fig. 10-13 are equivalent circuits of the 4 modes in the rectifying mode. The corresponding relationship between the on state of each switch unit and the corresponding mode is shown in fig. 15 b.
In the view of figure 15b of the drawings,、/>、/>、/>、/>、/>Representing that the corresponding switch is in an on state,/>、/>、/>、/>、/>、/>The mode marked as "\" and the unlisted mode represent that the corresponding switch is in the off state and the mode is an invalid mode.
When the circuit works in the rectification mode, the conducting states of the first switch unit S1 and the second switch unit S2 are judged according to the polarity (positive and negative) of the voltage at the alternating side. The first switching unit S1 is not operated in the ac side positive half cycle, and the second switching unit S2 is not operated in the ac side negative half cycle.
To simplify the difficulty in analyzing the operation modes of the double Buck-Boost inverter, the following assumptions are proposed: ① All devices in the circuit are ideal models, namely: the switch unit and the diode can be switched on or off instantaneously, and no conduction voltage drop exists when the switch unit and the diode are switched on (the resistance is 0 when the switch unit and the diode are switched on), and no leakage current exists when the switch unit and the diode are switched off; the inductor works in a linear region without saturation, and the parasitic resistance is zero; the equivalent series resistance of the capacitor is zero; ② The capacities of the filter capacitor C f and the filter capacitor C bus are large enough, and the current flowing through the filter capacitor C f and the filter capacitor C bus is approximately 0; ③ The circuit is in steady state operation.
The drive signal is analyzed by taking a square wave as an example, namely: the driving signals of the switch units are square wave sequences with fixed pulse width. When the driving signal of each switching unit Sa, sb, sc, sd is a PWM wave, the driving principle is substantially the same as that of a square wave, and thus, the driving signal is not limited to a square wave, but may be a PWM wave.
In the inversion mode, the operation modes of the circuit can be classified into a Continuous Conduction Mode (CCM) and a Discontinuous Conduction Mode (DCM) according to whether or not the current flowing through each inductor La, lb, lc, ld drops to zero. The two operations are substantially similar, and in DCM, the current of each inductor La, lb, lc, ld may drop to zero, which is not the case in CCM, and the CCM is taken as an example for subsequent analysis.
In the inversion mode, when the duty ratio of each switching unit is greater than 50%, each switching unit Sa and Sb, sc and Sd may be turned on at the same time, and when the duty ratio of each switching unit is less than 50%, this is not the case, and since the duty ratio of the driving signal is greater than 50% and affects the analysis process, the case where the duty ratio of each switching unit is less than 50% will be described.
Waveform analysis in inversion mode
As shown in fig. 14a, tg is an ac side voltage period, and Ts is a switching period. In the inversion mode, in order to realize grid connection, the working period of the first switch unit S1 and the second switch unit S2 is consistent with the alternating-current side voltage period. The alternating current side is in a positive half period, the first switch unit S1 is turned on, and the fifth switch unit Sc and the sixth switch unit Sd are conducted in a staggered mode; the second switch unit S2 is turned on, and the third switch unit Sa and the fourth switch unit Sb are alternately turned on during the negative half cycle of the alternating current side.
Further analysis is performed on a switching cycle of the positive half cycle of the ac side in fig. 14a, and the timing chart and the related waveforms are shown in fig. 14b, where in one switching cycle, the duty ratios of the fifth switching unit Sc and the sixth switching unit Sd are the same and the phases are 180 ° different.
As can be seen from fig. 14 b: in one switching cycle, the circuit can be divided into four cases, and in half an alternating-current side cycle, the four cases of the circuit appear in sequence and are cycled. Of the four cases, cases 1, 3 belong to modality a, and cases 2, 4 belong to modality b. Four cases will now be described in detail:
(1) Stage 1 (t 0 to t 1): the fifth switch unit Sc is triggered to be turned on, the terminal voltage of the fifth switch unit Sc drops to 0, and the current iSc flowing through the fifth switch unit Sc is the same as the current iLc of the third inductor Lc; the sixth switching unit Sd is turned off, the terminal voltage thereof is vbus+v0, and the current flowing through the sixth switching unit Sd is 0. The direct-current power supply Vbus charges and stores energy to the third inductor Lc, the inductor voltage vLc is constant at Vbus, and the inductor current iLc rises; the fourth inductor Ld supplies power to the load R L1, the inductor voltage vLd is constant at-V0, and the inductor current iLd drops. The third diode Dc is turned off by receiving a reverse voltage of vbus+v0, and its current iDc is 0; the fourth diode Dd turns on freewheels with a terminal voltage vDd of 0 and current iDd being the same as inductor current iLd.
(2) Stage 2 (t 1 to t 2): the fifth switch unit Sc and the sixth switch unit Sd are both turned off, the terminal voltages thereof are vbus+v0, and the currents flowing through the switch units are both 0. The third inductance Lc and the fourth inductance Ld simultaneously supply power to the load R L1, the voltage of the two inductances is constant at-V0, and the inductance current is reduced. The third diode Dc and the fourth diode Dd conduct freewheels, the terminal voltages of the third diode Dc and the fourth diode Dd are 0, and the current is the same as the corresponding inductance current.
(3) Stage 3 (t 2 to t 3): the sixth switch unit Sd is triggered to be conducted, the terminal voltage of the sixth switch unit Sd is reduced to 0, and the current iSd flowing through the sixth switch unit Sd is the same as the current iLd of the fourth inductor Ld; the fifth switching unit Sc is turned off, the terminal voltage thereof is vbus+v0, and the current flowing through the fifth switching unit Sc is 0. The direct-current power supply Vbus charges and stores energy to the fourth inductor Ld, the inductor voltage vLd is constant at Vbus, and the inductor current iLd rises; the third inductor Lc supplies power to the load R L1, the inductor voltage vLc is constant at-V0, and the inductor current iLc drops. The fourth diode Dd is turned off by receiving a reverse voltage of vbus+v0, and its current iDd is 0; the third diode Dc turns on freewheeling with a terminal voltage vDc of 0 and current iDc being the same as inductor current iLc.
(4) Stage 4 (t 3 to t 4): the fifth switch unit Sc and the sixth switch unit Sd are both turned off, the terminal voltages thereof are vbus+v0, and the currents flowing through the switch units are both 0. The third inductance Lc and the fourth inductance Ld simultaneously supply power to the load R L1, the voltage of the two inductances is constant at-V0, and the inductance current is reduced. The third diode Dc and the fourth diode Dd conduct freewheels, the terminal voltages of the third diode Dc and the fourth diode Dd are 0, and the current is the same as the corresponding inductance current.
From the above analysis, it can be seen that the ripple amount of the total current after the currents iLc, iLd in the two groups of interleaved chopper units are superimposed, i.e. the ripple amount of the load current in fig. 14b, is lower than the ripple amount of the current of any one group of branches, i.e. the ripple amount of the current iLc or iLd. This will help to reduce the inductance requirements of the circuit, reduce the circuit size, and increase the power density.
For the negative half cycle of the ac side, the analysis method is similar to that described above, and will not be repeated.
Waveform analysis in rectification mode
As shown in fig. 15a, ts is the switching period. In the rectification mode, the third switching unit Sa, the fourth switching unit Sb, and the second switching unit S2 operate in the ac side positive half cycle, and the fifth switching unit Sc, the sixth switching unit Sd, and the first switching unit S1 operate in the ac side negative half cycle. Fig. 15a only takes a certain switching period as an example for analysis, and for the negative ac half period, the analysis method is similar and will not be repeated.
As can be seen from fig. 15a, the circuit can be divided into two cases during one switching cycle, and the two cases of the circuit appear in sequence and cycle back and forth during half of the ac side cycle. Two cases will now be described in detail:
(1) Stage 1 (t 0 to t 1): the second switch unit S2 iS triggered to be turned on, the terminal voltage thereof drops to 0, and the current iS2 flowing through the second switch unit S2 iS the sum of the current iLa of the first inductor La and the current iLb of the second inductor Lb; the third switch unit Sa and the fourth switch unit Sb are turned off, the terminal voltages thereof are vbus+vg, and the currents flowing through the third switch unit Sa and the fourth switch unit Sb are 0. The ac power supply Vg charges and stores energy in the first inductor La and the second inductor Lb, and the inductor voltages vLa and vLb are the same as the ac power supply voltage Vg, and the inductor currents iLa and iLb rise. The first diode Da and the second diode Db conduct freewheeling, the terminal voltages vDa and vDb are 0, and the currents iDa and iDb are the same as the inductor currents iLa and iLb.
(2) Stage 2 (t 1 to t 2): the second switch unit S2 is turned off, the terminal voltages thereof are both- (vbus+v0), and the current flowing through the second switch unit S2 is 0; the third switch unit Sa and the fourth switch unit Sb are triggered and turned on, the terminal voltages thereof are all 0, and the currents flowing through the third switch unit Sa and the fourth switch unit Sb are the same as the inductance currents iLa and iLb. The first inductor La and the second inductor Lb supply power to the load R L2 at the same time, the voltage of the two inductors is constant at-Vbus, and the current of the inductors is reduced. The first diode Da and the second diode Db are turned off by the no-current loop, and the terminal voltages are both 0, and the currents are both 0.
The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above examples, and all technical solutions belonging to the concept of the present invention belong to the protection scope of the present invention. It should be noted that modifications and adaptations to the present invention may occur to one skilled in the art without departing from the principles of the present invention and are intended to be within the scope of the present invention.

Claims (9)

1. The utility model provides a two parallelly connected Buck-Boost dc-to-ac converter which characterized in that: the alternating current chopper comprises a direct current side port, a first alternating current chopper unit, a first switch unit, a second alternating current chopper unit, a second switch unit and an alternating current side port, wherein the first alternating current chopper unit comprises a third switch unit, a fourth switch unit, a first unidirectional conduction device, a second unidirectional conduction device, a first energy storage element and a second energy storage element, and the second alternating current chopper unit comprises a fifth switch unit, a sixth switch unit, a third unidirectional conduction device, a fourth unidirectional conduction device, a third energy storage element and a fourth energy storage element;
The first end part of the third switch unit, the first end part of the fourth switch unit, the first end part of the fifth switch unit and the first end part of the sixth switch unit are respectively and electrically connected with the positive electrode of the direct current side port, the positive electrode of the first unidirectional conduction device and the positive electrode of the second unidirectional conduction device are respectively and electrically connected with the negative electrode of the direct current side port through the first switch unit, the positive electrode of the third unidirectional conduction device and the positive electrode of the fourth unidirectional conduction device are respectively and electrically connected with the negative electrode of the direct current side port through the second switch unit, and the first end part of the first switch unit and the first end part of the second switch unit are respectively and electrically connected with the two ends of the alternating current side port;
The first end of the first energy storage element, the first end of the second energy storage element, the first end of the third energy storage element and the first end of the fourth energy storage element are respectively and electrically connected with the negative electrode of the first unidirectional conduction device, the negative electrode of the second unidirectional conduction device, the negative electrode of the third unidirectional conduction device and the negative electrode of the fourth unidirectional conduction device in a one-to-one correspondence manner, and the second end of the first energy storage element, the second end of the second energy storage element, the second end of the third energy storage element and the second end of the fourth energy storage element are respectively and electrically connected with the negative electrode of the direct current side port and the junction of the first switch unit.
2. The dual parallel Buck-Boost inverter of claim 1, wherein: the first switch unit, the second switch unit, the third switch unit, the fourth switch unit, the fifth switch unit and the sixth switch unit are bidirectional controllable switch elements, or two unidirectional controllable switch elements which are connected in reverse parallel and are not provided with body diodes, or two unidirectional controllable switch elements which are connected in reverse series and are provided with body diodes.
3. The dual parallel Buck-Boost inverter of claim 1 or 2, wherein: the first unidirectional conduction device, the second unidirectional conduction device, the third unidirectional conduction device and the fourth unidirectional conduction device are diodes or switching tubes.
4. The dual parallel Buck-Boost inverter of claim 1 or 2, wherein: the first energy storage element, the second energy storage element, the third energy storage element and the fourth energy storage element are inductors.
5. The dual parallel Buck-Boost inverter of claim 1 or 2, wherein: the direct current side port is provided with a direct current power supply, the alternating current side port is provided with an alternating current side filtering unit and an alternating current side load which are connected in parallel, and two ends of the alternating current side filtering unit are respectively and electrically connected with a first end part of the first switching unit and a first end part of the second switching unit, so that the double-parallel Buck-Boost inverter works in an inversion mode.
6. The dual parallel Buck-Boost inverter of claim 5, wherein: the DC side port is provided with a DC side filtering unit and a DC side load which are connected in parallel, the AC side port is provided with an AC power supply and an AC side filtering unit which is connected in parallel with two ends of the AC power supply, a first end part of the DC side filtering unit is electrically connected with a third switching unit, a fourth switching unit, a fifth switching unit and a sixth switching unit, a second end part of the DC side filtering unit is electrically connected with a second end part of a first inductor, two ends of the AC side filtering unit are respectively electrically connected with a first end part of the first switching unit and a first end part of the second switching unit, and the double-parallel Buck-Boost inverter works in a rectifying mode.
7. The dual parallel Buck-Boost inverter of claim 6, wherein: the alternating current side filtering unit and the direct current side filtering unit are filtering capacitors or LC circuits or LCL circuits.
8. A control method of a double parallel Buck-Boost inverter, suitable for controlling the double parallel Buck-Boost inverter according to any one of claims 1-7, comprising the steps of:
Applying a drive signal with a phase difference of 180 degrees to a third switch unit and a fourth switch unit in the first staggered chopping unit, and applying a drive signal with a phase difference of 180 degrees to a fifth switch unit and a sixth switch unit in the second staggered chopping unit;
In one power frequency period, the first staggered chopping unit and the second staggered chopping unit alternately work in respective half periods;
The on-state of the first switch unit and the second switch unit is changed by controlling the on-duty ratio of the third switch unit, the fourth switch unit, the fifth switch unit and the sixth switch unit, and the direct current side or the alternating current side is charged, so that the output alternating current voltage is higher or lower than the direct current bus voltage.
9. The control method of the double parallel Buck-Boost inverter of claim 8, wherein the double parallel Buck-Boost inverter comprises 8 operating modes in a power frequency period:
1) Inversion mode a: in the positive half period of the alternating current side, the second staggered chopping unit works, and the third switching unit, the fourth switching unit, the second switching unit, the first unidirectional conduction device, the second unidirectional conduction device, the third unidirectional conduction device and the fourth unidirectional conduction device are disconnected; the fifth switch unit and the sixth switch unit are sequentially conducted and have a time interval of 180 DEG phase angle; the first switch unit is turned on or turned off, the direct current side charges and stores energy to the third energy storage element and the fourth energy storage element through the fifth switch unit and the sixth switch unit, and the alternating current side load is powered by the alternating current side filter unit;
2) Inversion mode b: in the positive half cycle of the alternating current side, the second staggered chopping unit works, and the third switching unit, the fourth switching unit, the fifth switching unit, the sixth switching unit, the second switching unit, the first unidirectional conduction device and the second unidirectional conduction device are disconnected; the first switch unit, the third unidirectional conduction device and the fourth unidirectional conduction device are conducted; the energy in the third energy storage element and the fourth energy storage element is supplied to the alternating current side through the first switch unit, the third unidirectional conduction device and the fourth unidirectional conduction device;
3) Inversion mode c: in the negative half cycle of the alternating current side, the first staggered chopping unit works, and the fifth switching unit, the sixth switching unit, the first unidirectional conduction device, the second unidirectional conduction device, the third unidirectional conduction device and the fourth unidirectional conduction device are disconnected; the third switch unit and the fourth switch unit are sequentially conducted and the time interval is 180 DEG phase angle; the second switch unit is turned on or turned off, the direct current side charges and stores energy to the first energy storage element and the second energy storage element through the third switch unit and the fourth switch unit, and the alternating current side load is powered by the alternating current side filter unit;
4) Inversion mode d: in the negative half cycle of the alternating current side, the first staggered chopping unit works, and the third switching unit, the fourth switching unit, the fifth switching unit, the sixth switching unit, the first switching unit, the third unidirectional conduction device and the fourth unidirectional conduction device are disconnected; the second switch unit, the first unidirectional conduction device and the second unidirectional conduction device are conducted; the energy in the first energy storage element and the second energy storage element is supplied to the alternating current side through the second switch unit, the first unidirectional conduction device and the second unidirectional conduction device;
5) Rectification mode a: in the positive half cycle of the alternating current side, the first staggered chopping unit works, and the third switching unit, the fourth switching unit, the fifth switching unit, the sixth switching unit, the first switching unit, the third unidirectional conduction device and the fourth unidirectional conduction device are disconnected; the second switch unit, the first unidirectional conduction device and the second unidirectional conduction device are conducted; the alternating current side charges and stores energy to the first energy storage element and the second energy storage element through the second switch unit, the first unidirectional conduction device and the second unidirectional conduction device, and the direct current side load is powered by the direct current side filter unit;
6) Rectification mode b: in the positive half cycle of the alternating current side, the first staggered chopping unit works, and the fifth switching unit, the sixth switching unit, the first switching unit, the second switching unit, the first unidirectional conduction device, the second unidirectional conduction device, the third unidirectional conduction device and the fourth unidirectional conduction device are disconnected; the third switch unit and the fourth switch unit are sequentially conducted and the time interval is 180 DEG phase angle; the energy in the first energy storage element and the second energy storage element is supplied to the direct-current side load through the third switch unit and the fourth switch unit, and meanwhile, the direct-current side filter unit is charged with energy for energy storage;
7) Rectification mode c: in the negative half cycle of the alternating current side, the second staggered chopping unit works, and the third switching unit, the fourth switching unit, the fifth switching unit, the sixth switching unit, the second switching unit, the first unidirectional conduction device and the second unidirectional conduction device are disconnected; the first switch unit, the third unidirectional conduction device and the fourth unidirectional conduction device are conducted; the alternating current side charges and stores energy to the third energy storage element and the fourth energy storage element through the first switch unit, the third unidirectional conduction device and the fourth unidirectional conduction device, and the direct current side load is powered by the direct current side filter unit;
8) Rectification mode d: in the negative half cycle of the alternating current side, the second staggered chopping unit works, and the third switching unit, the fourth switching unit, the first switching unit, the second switching unit, the first unidirectional conduction device, the second unidirectional conduction device, the third unidirectional conduction device and the fourth unidirectional conduction device are disconnected; the fifth switch unit and the sixth switch unit are sequentially conducted and have a time interval of 180 DEG phase angle; the energy in the third energy storage element and the fourth energy storage element is supplied to the direct-current side load through the fifth switch unit and the sixth switch unit, and meanwhile the direct-current side filter unit is charged with energy for energy storage.
CN202110796745.3A 2021-07-14 2021-07-14 Double-parallel Buck-Boost inverter and control method thereof Active CN113364334B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110796745.3A CN113364334B (en) 2021-07-14 2021-07-14 Double-parallel Buck-Boost inverter and control method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110796745.3A CN113364334B (en) 2021-07-14 2021-07-14 Double-parallel Buck-Boost inverter and control method thereof

Publications (2)

Publication Number Publication Date
CN113364334A CN113364334A (en) 2021-09-07
CN113364334B true CN113364334B (en) 2024-06-18

Family

ID=77539445

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110796745.3A Active CN113364334B (en) 2021-07-14 2021-07-14 Double-parallel Buck-Boost inverter and control method thereof

Country Status (1)

Country Link
CN (1) CN113364334B (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115765449A (en) * 2022-10-14 2023-03-07 华为数字能源技术有限公司 Direct current conversion circuit and photovoltaic inverter

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN215186502U (en) * 2021-07-14 2021-12-14 锦浪科技股份有限公司 Double-parallel Buck-Boost inverter

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104901536A (en) * 2015-06-08 2015-09-09 南车青岛四方机车车辆股份有限公司 Bidirectional DC-DC voltage boosting and reduction system and energy storage system
CN110034674B (en) * 2018-01-12 2020-03-31 山东大学 High-gain bidirectional three-phase DC-DC converter and control method
CN108521218A (en) * 2018-04-24 2018-09-11 中国能源建设集团湖南省电力设计院有限公司 Bidirectional alternating expression DC/DC convertor devices suitable for a variety of energy-storage travelling wave tubes
CN109474058A (en) * 2018-11-16 2019-03-15 珠海泰通电气技术有限公司 The inverse control one power supply energy-storage system of photovoltaic off-grid and its power supply energy storage method
CN110868068B (en) * 2019-11-28 2021-06-04 重庆理工大学 Multiphase staggered parallel direct current converter and current sharing control method thereof

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN215186502U (en) * 2021-07-14 2021-12-14 锦浪科技股份有限公司 Double-parallel Buck-Boost inverter

Also Published As

Publication number Publication date
CN113364334A (en) 2021-09-07

Similar Documents

Publication Publication Date Title
CN107086770B (en) PFC circuit and variable frequency air conditioner
CN111355430B (en) Motor control circuit, charging and discharging method, heating method and vehicle
CN101895223B (en) Double-Cuk buck-boost output parallel-type converter
CN109980978B (en) Converter and modulation method thereof
CN108988634B (en) Three-phase interleaved bidirectional large-transformation-ratio DCDC converter and control method thereof
CN110957922A (en) Single-stage high-frequency isolated bidirectional direct-current converter and grid-connected energy storage system
CN108736756B (en) Improved double-auxiliary resonant-pole three-phase soft switching inverter circuit
CN106169885B (en) A kind of switch of tandem type six multi-electrical level inverter
CN110957923A (en) High-frequency isolation bidirectional direct current converter based on phase-shifted full bridge and grid-connected energy storage system
CN111342693B (en) Boost-buck photovoltaic grid-connected inverter
CN113328649A (en) Conversion circuit and control method thereof
CN113364334B (en) Double-parallel Buck-Boost inverter and control method thereof
CN211127589U (en) Single-stage high-frequency isolated bidirectional direct-current converter and grid-connected energy storage system
US20230253877A1 (en) Power factor correction and dc-dc multiplexing converter and uninterruptible power supply including the same
CN219875518U (en) Inverter and power supply system
CN209200934U (en) A kind of direct current tri-lever boosting converter merging coupling inductance technology
CN215186502U (en) Double-parallel Buck-Boost inverter
CN111327222A (en) Current transformation circuit
CN112224056A (en) Vehicle and energy conversion device thereof
CN211830581U (en) High-transformation-ratio bidirectional direct current conversion circuit
CN209767411U (en) Current transformation circuit
CN112737316A (en) quasi-Z-source inverter and power supply system
CN112072908A (en) Six-inductor double-switch PFC topological structure for improving UPS power factor
CN109560702A (en) A kind of direct current tri-lever boosting converter merging coupling inductance technology
CN218940745U (en) Electric automobile charger and AC-DC circuit 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
GR01 Patent grant