CN115051565A - Bidirectional half-bridge direct-current converter grid-connected inverter and ripple wave control method - Google Patents
Bidirectional half-bridge direct-current converter grid-connected inverter and ripple wave control method Download PDFInfo
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- H—ELECTRICITY
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- 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
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- H02M1/00—Details of apparatus for conversion
- H02M1/0003—Details of control, feedback or regulation circuits
- H02M1/0038—Circuits or arrangements for suppressing, e.g. by masking incorrect turn-on or turn-off signals, e.g. due to current spikes in current mode control
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- 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
- H02M1/007—Plural converter units in cascade
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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
- H02M1/08—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters
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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
- H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
- H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
- H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
- H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/53—Conversion of dc power input into ac power output without 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
- H02M7/537—Conversion of dc power input into ac power output without 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 using semiconductor devices only, e.g. single switched pulse inverters
- H02M7/5387—Conversion of dc power input into ac power output without 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 using semiconductor devices only, e.g. single switched pulse inverters in a bridge configuration
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Abstract
The invention discloses a bidirectional half-bridge direct-current converter grid-connected inverter and a ripple wave control method, wherein the method comprises the following steps: the first and second bi-directional half-bridge dc converter modules BHDC1 and BHDC2 and the fully-controlled inverter INV; according to the invention, an additional power decoupling circuit is not required to be introduced, and the output capacitor instantaneous voltage ripple complementation is realized by optimizing the control signal on the basis of the original circuit, so that the inherent contradiction between a small capacitance value and a low voltage ripple on a direct current bus is solved. Compared with other low-frequency ripple wave control methods, the control algorithm designed by the method is simple and effective, an additional power decoupling device is not required to be introduced, the function can be upgraded on the basis of the existing controller, and the requirements on passive elements in the system are greatly reduced.
Description
Technical Field
The invention belongs to the technical field of electric power, is suitable for application occasions of a non-isolated two-stage grid-connected inverter, and particularly relates to a bidirectional half-bridge direct-current converter grid-connected inverter and a ripple control method.
Background
The inversion technology is a key technology of a new energy power generation system. The two-stage single-phase inverter consists of a front-stage direct-current converter and a rear-stage single-phase inverter, wherein the front-stage direct-current converter converts an input direct-current voltage into a stable direct-current bus voltage, and the stable direct-current bus voltage is used as the input of the rear-stage single-phase inverter and is converted into a stable alternating current to be supplied to alternating-current equipment or be incorporated into a power grid. The method is widely applied to new energy power generation systems, uninterruptible power supplies, rail transit and the like. However, due to the inherent defects of the single-phase inverter, a voltage ripple with double power frequency fluctuation is inevitably generated on the direct current bus at the input side of the single-phase inverter, and the double frequency ripple has adverse effects on the performance of the inverter, for example, in a photovoltaic system, the double frequency ripple affects the accuracy of tracking the maximum power point of a battery panel, and the efficiency of the system is reduced; in an alternating current grid-connected system, the voltage harmonic problem fed into a power grid is increased due to the fluctuation of bus voltage, and the quality of electric energy is reduced.
In order to solve the problem of double-frequency ripple energy on the input side of a single-phase inverter, a passive power decoupling scheme is adopted in the traditional method, namely a filter circuit formed by an inductor and a capacitor is connected in parallel on a direct-current bus to reduce voltage ripples, and in order to make the suppression effect obvious, passive elements such as a large inductor and a large capacitor are generally needed, so that the problems of increase in the volume of the device, reduction in power density, shortening of the service life and the like are caused.
In order to overcome the defects of the conventional scheme, a scheme of an active decoupling technology is generally adopted. The decoupling circuit is added on the basis of the original circuit, the compensation of the buffer capacitor on the secondary ripple is completed by controlling the power switch tube in the decoupling circuit, and the function of ripple control is realized while the adoption of a large capacitor and a large inductor is avoided. However, since an additional auxiliary circuit needs to be introduced to increase the control link of the decoupling circuit, the decoupling circuit has the disadvantages of high cost, increased control difficulty, complex circuit structure and the like for the industry.
Disclosure of Invention
In order to solve the problems in the prior art, the invention aims to provide a bidirectional half-bridge direct-current converter grid-connected inverter and a ripple control method.
In order to achieve the purpose, the invention adopts the following technical means:
a bi-directional half-bridge dc converter grid-connected inverter comprising: the first and second bi-directional half-bridge dc converter modules BHDC1 and BHDC2 and the fully-controlled inverter INV;
the first bi-directional half-bridge DC converter module BHDC1 includes an input DC power source V in 1. Input inductance L 1 MOSFET power tube S 1 And MOSFET power tube S 2 Starting the process; the input DC power supply V in The anode of 1 is connected with one end of an input inductor L1, and the other end of the input inductor L1 is connected with a MOSFET power tube S 1 Drain electrode of (1), MOSFET power tube S 2 Source stage of (2), diode D 1 Cathode and diode D 2 Anode of (2), MOSFET power tube S 1 Source input dc power supply V in 1 negative pole, MOSFET power transistor S 2 Drain connected to diode D 2 Cathode and output capacitor C 1 Positive electrode of (2), output capacitor C 1 Negative pole of the DC power supply V in 1, a negative electrode;
the second bi-directional half-bridge DC converter module BHDC2 includes an input DC power source V in 2. Input inductance L 2 MOSFET power tube S 3 And MOSFET power tube S 4 (ii) a The input DC power supply V in 2 positive pole and input DC power supply V in 1 is connected with the negative pole of the power supply and is input with a direct current power supply V in 2 negative pole connected to one end of input inductor L2, and the other end of input inductor L2 connected to MOSFET power transistor S 3 Source electrode of and MOSFET power tube S 4 Drain electrode of (2), diode D 3 And diode D 4 Cathode of (2), diode D 3 Cathode of the power supply is connected with an input direct current power supply V in 2 positive electrode, MOSFET power transistor S 3 Is connected with an input direct current power supply V in 2 positive electrode of MOSFET power transistor S 3 Source-connected diode D 4 Cathode of the capacitor is connected with an output capacitor C 2 Negative electrode of (1), output capacitor C 2 Positive pole of the DC power supply V in 2 is a positive electrode;
the full-control inverter INV comprises a full-control inverter bridge and a filter inductorL f And a filter capacitor C f (ii) a Output capacitor C 1 And output capacitor C 2 The input end of the full-control inverter bridge is connected in series; the positive output of the full-controlled inverter bridge is connected with an inductor L f The output of the negative pole of the full-control inverter bridge is connected with the common ground at the AC side; filter capacitor C f And a load resistance R L Connected in parallel and one end of which is connected with an inductor L f And the other end of the anode is connected to a common ground on the AC side.
As a further improvement of the invention, the fully-controlled inverter bridge consists of four MOSFET power tubes S ap 、S an 、 S bp 、S bn And (4) forming.
As a further improvement of the present invention, the relationship between the double frequency power of the bidirectional half-bridge dc converter grid-connected inverter satisfies:
wherein, P C1_2ω Is a capacitor C 1 Above double frequency ripple power, P C2_2ω Is a capacitor C 2 Above double frequency ripple power, P o-2ω Is the double frequency ripple power, P, of the AC side of the inverter in_2ω Is the double frequency ripple power of the input DC power supply.
As a further development of the invention, the output capacitance C 1 And output capacitor C 2 The capacitance value C of the capacitor meets the following requirements:
in the formula I bus_2ω_m Is the amplitude of a double frequency component of the DC bus current, V bus Is the DC component of the DC bus voltage, ω is the AC side fundamental angular frequency, V in Is the input voltage of the bi-directional half-bridge dc converter module.
A ripple control method of a bidirectional half-bridge direct current converter grid-connected inverter comprises the following steps:
by means of a capacitor C 1 And C 2 The double frequency ripple energy in the buffer system is actively controlled to form a complementary state by controlling the capacitor voltage ripple, so that the direct current bus capacitor voltage ripple is reduced;
the control signal of the power tube is composed of a complementary component and a compensation component, the complementary component is generated and controlled by a controlled target complementary voltage ripple, and a direct current working point voltage stabilizing loop is added to generate the compensation component;
the bidirectional half-bridge direct current converter module automatically switches the working state of boosting or reducing voltage according to the direction of output current in a frequency doubling period.
As a further improvement of the invention, the DC operating point voltage is controlled by adopting two single-voltage closed-loop structures:
first single voltage closed loop: real-time sampling output capacitor C 1 Is measured by the instantaneous voltage v C1 Filtering out ripple signals with fixed frequency after passing through a frequency doubling trap to obtain direct current component V C1 ，V C1 Half of the steady-state average value of the DC bus voltage
Subtracted as a voltage loop regulator G v1 I, the output current judging module 1 monitors i in real time out1 If i is out1 >0, judging the output of the module to be 1; if i out1 <0, judging that the output of the module is 0; judging module output result and voltage ring regulator G v1 The output of the power transistor is multiplied by a multiplier to obtain the MOSFET power transistor S 1 DC working point compensating duty ratio signal
Regulator G with voltage loop after negation of output result of judgment module v1 The output of the power transistor is multiplied by a multiplier to obtain the MOSFET power transistor S 2 DC working point compensating duty ratio signal
Second single voltage closed loop: real-time sampling output capacitor C 2 Is measured by the instantaneous voltage v C2 Filtering out ripple signals with fixed frequency after passing through a frequency doubling trap to obtain direct current component V C2 ，V C2 Half of the steady-state average value of the DC bus voltage
Subtracted as a voltage loop regulator G v2 I, the output current judging module 3 monitors in real time out2 If i is out2 >0, judging the output of the module to be 1; if i out2 <0, judging that the output of the module is 0; judging module output result and voltage ring regulator G v1 The output of the power transistor is multiplied by a multiplier to obtain the MOSFET power transistor S 3 DC working point compensating duty ratio signal
Regulator G with voltage loop after negation of output result of judgment module v2 The output of the power transistor is multiplied by a multiplier to obtain the MOSFET power transistor S 4 DC working point compensating duty ratio signal
As a further improvement of the present invention, the complementary control of the capacitor voltage ripple is: the output currents i of the first and second bidirectional half-bridge DC converter modules BHDC1 and BHDC2 are obtained by calculating the complementary output capacitor voltages out1 、i out2 Obtaining the control quantity d according to the circuit relation of the bidirectional half-bridge DC converter 1 、d 2 、d 3 、d 4 Compensating duty ratio signal of control quantity and corresponding DC working point
Adding to obtain final duty ratio signal, and generating switching signal by using modulation wave to realize MOSFET power tube S 1 、S 2 、S 3 、S 4 And (4) controlling.
As a further improvement of the present invention, the expression of the output capacitor voltage is:
wherein v is C1 、v C2 Representing the output capacitance C 1 、C 2 Instantaneous voltage of V bus Representing the DC component of the DC bus voltage, I bus_2ω_m Representing the amplitude of a double frequency component of the DC bus current, and C representing an output capacitor C 1 、C 2 ω represents the power frequency angular frequency of the ac side inverter output ac flow.
As a further development of the invention, the output current i out1 、i out2 The calculation formula of (A) is as follows:
in the formula, wherein I bus_2ω_m Is the amplitude of the double frequency current of the inverter, omega represents the power frequency angular frequency of the output alternating current of the inverter at the alternating current side, C represents the output capacitor C 1 、C 2 Volume value of (V) bus Representing the dc component of the dc bus voltage.
As a further improvement of the invention, in the capacitor C 1 Capacitor C 2 Under the condition that the capacitance value is the same as the voltage of the direct current working point, the MOSFET power tube S 1 MOSFET power tube S 2 MOSFET power tube S 3 MOSFET power tube S 4 Control signal ofThe calculation formula is as follows:
wherein d is 1 、d 2 、d 3 、d 4 Respectively representing MOSFET power tubes S 1 、S 2 、S 3 、S 4 Duty cycle, v C1 Representing the output capacitance C 1 Instantaneous voltage of v C2 Representing the output capacitance C 2 Instantaneous voltage of T s Is the switching period of the switching tube, i out1 、i out2 Output currents, V, of the first and second bi-directional half-bridge DC converter modules BHDC1 and BHDC2, respectively in 1、V in 2 are the input voltages of the first and second bi-directional half-bridge dc converter modules BHDC1 and BHDC2, respectively.
Compared with the prior art, the invention has the following advantages:
according to the invention, an additional power decoupling circuit is not required to be introduced, and the output capacitor instantaneous voltage ripple complementation is realized by optimizing the control signal on the basis of the original circuit, so that the inherent contradiction between a small capacitance value and a low voltage ripple on a direct current bus is solved. The traditional design adopts a bidirectional half-bridge DC-DC modular DC converter with an Input Series and Output Series (ISOS) structure, the control signals of switching devices are the same, the voltage of a bus capacitor fluctuates synchronously, the energy of double frequency ripple waves cannot be buffered effectively, the voltage ripple can be reduced only by selecting a capacitor with a large capacitance value, and the inevitable problems of reduced power density of the device, shortened service life of components, reduced stability of equipment and the like are brought. On the premise of ensuring low bus voltage ripple, the invention greatly reduces the capacitance value requirement of the bus capacitor by optimizing the control signal of the switching device and improves the comprehensive performance of the device. According to the two-stage single-phase inverter system designed based on the method, the voltage ripple of the direct-current bus is reduced to be less than 5% of that of the existing design. Compared with other low-frequency ripple wave control methods, the control algorithm designed by the method is simple and effective, an additional power decoupling device is not required to be introduced, the function can be upgraded on the basis of the existing controller, and the requirements on passive elements in the system are greatly reduced.
Drawings
The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. In addition, the shapes, the proportional sizes, and the like of the respective members in the drawings are merely schematic for facilitating the understanding of the present invention, and do not specifically limit the shapes, the proportional sizes, and the like of the respective members of the present invention. In the drawings:
FIG. 1 is a circuit topology employed by the present invention;
FIG. 2 is a graph of the output current of a circuit employed in the present invention;
FIG. 3a is an equivalent circuit topology diagram of a first bi-directional half-bridge DC converter module used in the present invention operating in a boost circuit state;
FIG. 3b is an equivalent circuit topology diagram of a first bi-directional half-bridge DC converter module used in the present invention operating in a buck circuit state;
FIG. 4a is an equivalent circuit topology diagram of a second bidirectional half-bridge DC converter module used in the present invention operating in a boost circuit state;
FIG. 4b is an equivalent circuit topology diagram of a second bidirectional half-bridge DC converter module used in the present invention operating in a buck circuit state;
FIG. 5 is a control block diagram of a pre-stage bidirectional half-bridge DC converter module employed in the present invention;
FIG. 6 is a waveform diagram of a state quantity of a circuit corresponding to a ripple control method according to the present invention;
FIG. 7a shows the voltage v across two output capacitors without the complementary control algorithm proposed by the present invention C1 、v C2 DC bus voltage v bus A waveform of the waveform;
FIG. 7b shows the AC output voltage v without the complementary control algorithm proposed by the present invention ac The waveform of (a);
FIG. 8a shows the voltage v across two output capacitors using the complementary control algorithm proposed by the present invention C1 、 v C2 And the DC bus voltage v bus The waveform of (a);
FIG. 8b shows the AC output voltage v using the complementary control algorithm proposed by the present invention ac And (4) waveform.
Detailed Description
In order to make those skilled in the art better understand the technical solution of the present invention, the technical solution in the embodiment of the present invention will be clearly and completely described below with reference to the drawings in the embodiment of the present invention, and it is obvious that the described embodiment is only a part of the embodiment of the present invention, and not all embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, shall fall within the scope of protection of the present invention.
It will be understood that when an element is referred to as being "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only and do not denote a single embodiment.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.
In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the embodiments are only a part of the embodiments of the present invention, not all of the embodiments, and are not intended to limit the scope of the present disclosure. Moreover, in the following description, descriptions of well-known structures and techniques are omitted so as to not unnecessarily obscure the concepts of the present disclosure. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The key point of the invention is that the capacitor voltage ripple is designed to be in a complementary state according to the transmission relation of the double-frequency power of the two-stage bidirectional half-bridge DC converter grid-connected inverter, so that the double-frequency ripple power of the single-phase inverter is completely born by the output capacitor, the output current of the bidirectional half-bridge DC converter module is obtained according to the designed voltage ripple amount, the working modes of the bidirectional half-bridge DC converter are switched according to the magnitude of the output current, and the ripple control method with two output capacitor voltages being complementary is obtained in each mode according to the working principle.
The invention relates to a grid-connected inverter for actively inhibiting low-frequency ripple cascaded bidirectional half-bridge direct-current converter, which comprises: the first and second bi-directional half-bridge dc converter modules BHDC1 and BHDC2 and the fully-controlled inverter INV;
comprising 2 input DC power supplies V in1 Input DC power supply V in 2, 2 first and second bi-directional half-bridge dc converter modules BHDC1 and BHDC2 and 1 fully-controlled inverter bridge INV, wherein the first and second bi-directional half-bridge dc converter modules BHDC1 and BHDC2 adopt an input-series output-series (ISOS) structure;
input DC power supply V in The anode of the 1 is connected with the input anode of the first bidirectional half-bridge DC converter module BHDC1, and a DC power supply V is input in The cathode of the 1 is connected with the input cathode of the first bidirectional half-bridge DC converter module BHDC1 and the input anode of the second bidirectional half-bridge DC converter module BHDC2, and is input with a DC power supply V in 2 is connected with the input cathode of the first bidirectional half-bridge DC converter module BHDC1 and the input anode of the second bidirectional half-bridge DC converter module BHDC2, and is input with a DC power supply V in The cathode of the second bi-directional half-bridge direct-current converter module BHDC2 is connected with the input cathode of the second bi-directional half-bridge direct-current converter module BHDC2, the output anode of the first bi-directional half-bridge direct-current converter module BHDC1 is connected with the anode of the full-control inverter bridge INV direct-current bus, the output cathode of the first bi-directional half-bridge direct-current converter module BHDC1 is connected with the output anode of the second bi-directional half-bridge direct-current converter module BHDC2, the output cathode of the second bi-directional half-bridge direct-current converter module BHDC2 is connected with the cathode of the full-control inverter bridge INV direct-current bus, and the output of the full-control inverter bridge is connected with the single-phase alternating-current power grid V grid ；
The first bi-directional half-bridge DC converter module BHDC1 includes an input inductor L 1 2N-channel MOSFET power tube Q with reverse diode 1 MOSFET power tube Q 2 An output capacitor C 1 . Input inductance L 1 Positive pole input DC power supply V in 1 positive pole, input inductance L 1 Negative electrode connected with MOSFET power tube Q 1 Drain electrode of and MOSFET power transistor Q 2 Source stage of (1), MOSFET power transistor Q 1 Source of the DC power source Vin 1 Negative electrode of (1), MOSFET power transistor Q 2 Is connected with the output capacitor C 1 Positive electrode of (1), output capacitor C 1 Is connected with the output anode of the first bidirectional half-bridge DC converter module BHDC1, and an output capacitor C 1 Negative pole of the DC power supply V in 1 is used as a negative electrode.
The second bidirectional half-bridge DC converter module BHDC2 includes an input inductor L 2 2N-channel MOSFET power tube Q with reverse diode 3 MOSFET power tube Q 4 An output capacitor C 2 . Input inductance L 2 Negative electrode input DC power supply V in2 Is negativePole, input inductance L 2 Positive electrode connected with MOSFET power tube Q 3 Source electrode of and MOSFET power transistor Q 4 Drain electrode of (1), MOSFET power transistor Q 3 Is connected with an input direct current power supply V in 2 positive electrode, MOSFET power transistor Q 2 Source stage of is connected with output capacitor C 2 Negative electrode of (1), output capacitor C 2 Positive pole of the DC power supply V in 2 positive electrode, output capacitor C 2 Is connected to the output cathode of the second bi-directional half-bridge dc converter module BHDC 2.
Preferably, the fully-controlled inverter bridge consists of four MOSFET power tubes S ap 、S an 、S bp 、S bn And (4) forming.
Preferably, the control target of the bidirectional half-bridge DC converter grid-connected inverter with the capability of inhibiting the low-frequency ripple is to output the required frequency-doubled ripple power P o-2ω All from DC bus capacitor C 1 And C 2 The output capacitor voltage ripples are controlled to be in a complementary state, so that the double frequency ripples on the direct current bus voltage are reduced.
The circuit does not need to introduce an additional power decoupling device, and realizes the output capacitor voltage ripple complementation by optimizing a traditional control algorithm, thereby reducing the direct current bus voltage ripple and having the capability of inhibiting the low-frequency ripple. The design avoids adverse effects caused by feeding low-frequency ripple energy into the direct current side of the single-phase inverter while realizing basic functions of circuit boosting and inversion, can greatly reduce the capacitance value required by the direct current bus capacitor by adopting the method under the amplitude value of the same voltage ripple, improves the power density of the device, and has the advantages of small bus capacitor, low voltage ripple, no need of changing the circuit structure and other comprehensive performance.
As shown in FIG. 1, a circuit diagram adopted by the ripple control method of the present invention includes an input DC power supply V in 1. Input DC power supply V in 2. Input inductance L 1 An input inductor L 2 MOSFET power tube S 1 MOSFET power tube S 2 MOSFET power tube S 3 MOSFET power tube S 4 Diode D 1 Diode D 2 Diode D 3 Diode D 4 Capacitor C 1 Capacitor C 2 Full-control inverter bridge S ap 、S an 、S bp 、 S bn Filter inductor L f Filter capacitor C f And a load resistance R L ；
The input DC power supply V in 1 positive pole connected with input inductance L 1 One terminal of (1), input inductance L 1 The other end of the MOSFET power tube S is connected with the MOSFET power tube S 1 Drain electrode of (1), MOSFET power tube S 2 Source stage of (2), diode D 1 Cathode and diode D 2 Anode of (2), MOSFET power transistor S 1 Source input dc power supply V in 1 negative pole, MOSFET power transistor S 2 Drain connected to diode D 2 Cathode and output capacitor C 1 Positive electrode of (2), output capacitor C 1 Negative pole of the DC power supply V in 1 is used as a negative electrode.
The input DC power supply V in 2 positive pole and input DC power supply V in 1 is connected with the negative pole of the power supply and is input with a direct current power supply V in 2 negative pole connected to one end of input inductor L2, and the other end of input inductor L2 connected to MOSFET power transistor S 3 Source electrode of and MOSFET power tube S 4 Drain electrode of (2), diode D 3 And diode D 4 Cathode of (2), diode D 3 Cathode of the power supply is connected with an input direct current power supply V in 2 positive electrode, MOSFET power transistor S 3 Is connected with an input direct current power supply V in 2 positive electrode, MOSFET power transistor S 3 Source-connected diode D 4 Cathode of the capacitor is connected with an output capacitor C 2 Negative electrode of (1), output capacitor C 2 Positive pole of the DC power supply V in 2. Capacitor C 1 And a capacitor C 2 The input end of the full-control inverter bridge is connected in series; the positive output of the full-controlled inverter bridge is connected with an inductor L f The output of the negative pole of the full-control inverter bridge is connected with the common ground at the AC side; capacitor C f And a load resistance R L Connected in parallel and one end of which is connected with an inductor L f And the other end of the anode is connected to a common ground on the AC side.
The calculation process of the control algorithm for compensating the double frequency ripples comprises the following steps:
inversionWhen the grid-connected device runs, the input direct current is generally converted into power frequency alternating current by adopting a PWM (pulse width modulation) technology, and the alternating current output side of the device is accessed into a single-phase alternating current power grid after the switching frequency harmonics are filtered by an LC (inductance-capacitance) filter. The specific implementation of the PWM pulse width modulation technique is: selecting modulation wave as single-phase power grid frequency sine wave v con Msin (ω t), where M is the modulation degree and the carrier wave is a bipolar high-frequency triangular wave v tri When v is tri <v con When S is present ap And S bn Conduction, S an And S bp Turn off, the midpoint voltage of two bridge arms of the inverter is v bus . When v is tri >v con When S is present an And S bp Conduction, S ap And S bn The switching-off is carried out, the midpoint voltage of two bridge arms of the inverter is-v bus . Grid-connected voltage v of inverter g (t) is the average of the bridge arm midpoint voltage over one carrier period:
v g (t)＝MV bus sin(ωt)＝V g sin(ωt) (1)
wherein V g Is the amplitude of the grid-connected voltage.
Assuming that the power factor of the grid-connected inverter is 1, the available inverter alternating current side current is:
i g (t)＝I g sin(ωt) (2)
wherein I g Is the magnitude of the grid-connected current.
The DC bus current i is known from the switching state of the inverter bus (t) can be further expressed as:
wherein I bus Is a direct bus current i bus Direct current component of (t), i bus_2ω Is a direct bus current i bus The second harmonic component of (t), M is the modulation factor.
When the DC bus voltage is maintained constant v bus ＝V bus The input power of the inverter is expressed as:
P invi ＝V bus I bus +V bus i bus_2ω (4)
assume that the output capacitance voltage is expressed as:
wherein, V C1 、V C2 Is a DC component of the output capacitor voltage of magnitude
v C1t 、v C2t The ripple quantity of the capacitor voltage is electrically output, and the ripple of the output capacitor voltage satisfies a complementary relation for the bus capacitor voltage to have no ripple: v. of C1t +v C2t ＝0。
Suppose that the double frequency ripple of the inverter is completely controlled by the output capacitor C 1 Output capacitor C 2 Buffering:
wherein C is an output capacitor C 1 An output capacitor C 2 The capacity value of (c).
By solving the differential equation, the required capacitor voltage ripple can be solved as follows:
wherein I bus_2ω_m Is the amplitude of a frequency doubling component of the direct current bus current, and k is a undetermined constant. The voltage ripple expression yields design constraints for three circuit parameters:
from the mathematical constraints, k should satisfy: k is more than or equal to 1.
The capacitor voltage is constantly greater than 0, and the ripple amplitude of the capacitor voltage should not exceed the dc operating point:
thus forming a first constraint of the capacitance parameter:
the second constraint of the capacitance parameter is derived from the condition that the input voltage of the bi-directional half-bridge dc-dc converter is higher than the input voltage:
when k obtains the minimum value, the bus capacitance requirement is minimum, and k is 1 and is brought into the optimization interval of the obtained capacitance parameter:
wherein, I bus_2ω_m Is the amplitude of a double frequency component of the DC bus current, V bus Is the DC component of the DC bus voltage, ω is the AC side fundamental angular frequency, V in Is the input voltage of the bi-directional half-bridge dc converter module.
And simultaneously obtaining a capacitance voltage expression as follows:
the capacitance current calculation formula is:
the output currents of the first and second bi-directional half-bridge dc converter modules BHDC1 and BHDC2 are:
output current i out1 、i out2 According to the output current direction, the corresponding operation mode of the bidirectional half-bridge DC converter module and the power tube S 1 、S 2 、S 3 、S 4 The states are shown in table 1:
TABLE 1
The first bi-directional half-bridge dc converter module BHDC1 and the second bi-directional half-bridge dc converter module BHDC2 operate independently of each other, and there is no coupling relationship, so the control signals are independent of each other.
Output current i out1 >At 0, the first bi-directional half-bridge dc converter module BHDC1 operates in boost mode, the module equivalent circuit is as shown in fig. 3a, and in discontinuous mode, the power tube S1 controls the output current i of the module out1 And further control the output capacitor C 1 The waveform of the voltage of (c). According to the circuit characteristics, the following can be obtained:
wherein d is 1 Is a power tube S 1 The corresponding duty ratio of the control voltage ripple complementation is realized, the control voltage ripple complementation comprises a direct current component and a frequency multiplication component, under the control signal, the output current is greater than 0, and the capacitor C 1 Charging, ripple voltage v C1t In the positive half cycle.
Output current i out1 <At 0, the first bi-directional half-bridge dc converter module BHDC1 operates in buck mode, and the module equivalent circuit is shown in fig. 3b, in discontinuous mode, by the power transistor S 2 Control satisfaction module output current i out1 And further control the output capacitor C 1 The waveform of the voltage of (c). According to the circuit characteristics, the following can be obtained:
wherein d is 2 Is a power tube S 2 The corresponding duty ratio of the control voltage ripple complementation is realized, the corresponding duty ratio comprises a direct current component and a frequency multiplication component, under the control signal, the output current is less than 0, and the capacitor C 1 Discharge, ripple voltage v C1t In the negative half cycle.
Output current i out2 >At 0, the second bi-directional half-bridge dc converter module BHDC2 operates in boost mode, and the module equivalent circuit is shown in fig. 4a, in discontinuous mode, by the power tube S 3 Control satisfaction module output current i out1 And further control the output capacitor C 1 The waveform of the voltage of (c). According to the circuit characteristics, the following can be obtained:
wherein d is 3 Is a power tube S 3 The corresponding duty ratio of the control voltage ripple complementation is realized, the corresponding duty ratio comprises a direct current component and a frequency multiplication component, under the control signal, the output current is greater than 0, and the capacitor C 2 Charging, ripple voltage v C2t In the positive half cycle.
Output current i out2 <At 0, the second bi-directional half-bridge dc converter module BHDC2 operates in buck mode, and the equivalent circuit of the module is shown in fig. 4b, in discontinuous mode, by the power transistor S 4 Control satisfaction module output current i out2 And further control the output capacitor C 2 The waveform of the voltage of (c). According to the circuit characteristics, the following can be obtained:
wherein d is 4 Is a power tube S 4 Corresponding duty ratio for realizing control voltage ripple complementation, comprising direct current component and frequency multiplication componentUnder the control signal, the output current is less than 0, and the capacitor C 2 Discharge, ripple voltage v C2t In the negative half cycle.
The invention also discloses a control method of the double-frequency ripple control circuit of the two-stage fully-controlled inverter bridge of the bidirectional half-bridge direct-current converter with serial input and serial output, which comprises the following steps:
the control signal of the power tube is composed of a complementary component and a compensation component, the complementary component is generated and controlled by a controlled target complementary voltage ripple, and a direct current working point voltage stabilizing loop is added to generate the compensation component, so that the bus voltage is ensured to be stable:
two single-voltage closed-loop structures are adopted for the direct current working point voltage:
first single voltage closed loop: real-time sampling output capacitor C 1 Is measured by the instantaneous voltage v C1 Filtering out ripple signals with fixed frequency after passing through a frequency doubling trap to obtain direct current component V C1 ，V C1 Half of the steady-state average value of the DC bus voltage
Subtracted as a voltage loop regulator G v1 I, the output current judging module 1 monitors i in real time out1 If i is out1 >0, judging the output of the module to be 1; if i out1 <And 0, the output of the judging module is 0. Judging module output result and voltage ring regulator G v1 The output of the power transistor is multiplied by a multiplier to obtain the MOSFET power transistor S 1 DC working point compensating duty ratio signal
The output result of the judgment module is inverted and then is connected with a voltage loop regulator G v1 The output of the power transistor is multiplied by a multiplier to obtain the MOSFET power transistor S 2 DC working point compensating duty ratio signal
And
and inputting the capacitance voltage complementary formula into a capacitance voltage complementary formula calculation module.
Second single voltage closed loop: real-time sampling output capacitor C 2 Is measured by the instantaneous voltage v C2 Filtering out ripple signals with fixed frequency after passing through a frequency doubling trap to obtain direct current component V C2 ，V C2 Half of the steady-state average value of the DC bus voltage
Subtracted as a voltage loop regulator G v2 I, the output current judging module 3 monitors in real time out2 If i is out2 >0, judging the output of the module to be 1; if i out2 <And 0, the output of the judging module is 0. Judging module output result and voltage ring regulator G v1 The output of the power transistor is multiplied by a multiplier to obtain the MOSFET power transistor S 3 DC working point compensating duty ratio signal
The output result of the judgment module is inverted and then is connected with a voltage loop regulator G v2 The output of the power transistor is multiplied by a multiplier to obtain the MOSFET power transistor S 4 DC working point compensating duty ratio signal
And
and inputting the capacitance voltage complementary formula into a capacitance voltage complementary formula calculation module.
Complementary control of capacitor voltage ripple: the output currents i of the first and second bidirectional half-bridge DC converter modules BHDC1 and BHDC2 are obtained by calculating the complementary output capacitor voltages out1 、i out2 Based on bidirectional half-bridge DC convertersRelation, obtaining a control quantity d 1 、d 2 、d 3 、 d 4 Compensating duty ratio signal of control quantity and corresponding DC working point
Adding to obtain final duty ratio signal, and generating switching signal by using modulation wave to realize MOSFET power tube S 1 、S 2 、S 3 、 S 4 And (4) controlling.
A control block diagram of the converter is thus established as shown in fig. 5.
Through the direct control to the direct current bus voltage ripple, the voltage on the electric capacity is stabilized in direct current operating point, and the ripple is controlled to complementary state, when realizing converter power conversion, has reduced the demand of direct current bus voltage ripple and direct current bus electric capacity.
In order to verify the theoretical analysis of the converter, the invention provides a design example.
The converter parameters are as follows: v bus ＝400V、I bus ＝2A、V in 1＝60V、V in 2＝60V、V C1 ＝200V、V C2 ＝200V、 f S1 ＝10kHz、f S2 ＝10kHz、f ac ＝50Hz、C 1 ＝200μF、C 2 ＝200μF、L 1 ＝0.01mH、L 2 ＝0.01mH、 L f ＝0.0194H、C f ＝1.3μF、R L ＝60.45Ω、M＝0.7775。
FIG. 7a shows the voltage v across the two output capacitors without the complementary control algorithm proposed by the present invention C1 、 v C2 DC bus voltage v bus Waveform of the waveform, v C1 、v C2 Ripple synchronous fluctuation superposed on DC bus voltage v bus The double frequency fluctuation quantity appears, and the ripple quantity is 41.85V.
FIG. 7b shows the AC output voltage v without the complementary control algorithm proposed by the present invention ac The waveform of (2). At the input DC bus voltage v bus Under the condition of double frequency ripple, the output power of the post full bridge inverterThe pressure waveform produced some distortion, with a THD of 4.63%.
FIG. 8a shows the voltage v across two output capacitors using the complementary control algorithm proposed by the present invention C1 、 v C2 And the DC bus voltage v bus Can be seen from the figure, v C1 And v C2 The voltages of the direct current working points are the same and are half of the steady-state value of the direct current bus voltage. Through a complementary control algorithm, the ripple voltage waveforms form complementary states as desired. The voltage ripple of the direct current bus is reduced to about 2V, and is reduced by 95.22% compared with 41.85V without algorithm control.
FIG. 8b shows the AC output voltage v using the complementary control algorithm proposed by the present invention ac And (4) waveform. Under the condition that the input direct current bus voltage ripple is improved, the output voltage waveform distortion is reduced, and the output voltage THD is reduced to 1.17%.
Many embodiments and many applications other than the examples provided would be apparent to those of skill in the art upon reading the above description. The scope of the present teachings should, therefore, be determined not with reference to the above description, but should instead be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. The disclosures of all articles and references, including patent applications and publications, are hereby incorporated by reference for all purposes. The omission in the foregoing claims of any aspect of subject matter that is disclosed herein is not intended to forego such subject matter, nor should the applicant consider that such subject matter is not considered part of the disclosed subject matter.
The foregoing is a more detailed description of the invention and it is not intended that the invention be limited to the specific embodiments described herein, but that various modifications, alterations, and substitutions may be made by those skilled in the art without departing from the spirit of the invention, which should be construed to fall within the scope of the invention as defined by the appended claims.
Claims (10)
1. A bidirectional half-bridge DC converter grid-connected inverter, comprising: the first and second bi-directional half-bridge dc converter modules BHDC1 and BHDC2 and the fully-controlled inverter INV;
the first bi-directional half-bridge DC converter module BHDC1 includes an input DC power source V in 1. Input inductance L 1 MOSFET power tube S 1 And MOSFET power tube S 2 Starting the process; the input DC power supply V in The anode of 1 is connected with one end of an input inductor L1, and the other end of the input inductor L1 is connected with a MOSFET power tube S 1 Drain electrode of (1), MOSFET power tube S 2 Source stage of (2), diode D 1 Cathode and diode D 2 Anode of (2), MOSFET power tube S 1 Source input dc power supply V in 1 negative pole, MOSFET power transistor S 2 Drain connected to diode D 2 Cathode and output capacitor C 1 Positive electrode of (2), output capacitor C 1 Negative pole of the DC power supply V in 1, a negative electrode;
the second bi-directional half-bridge DC converter module BHDC2 includes an input DC power source V in 2. Input inductance L 2 MOSFET power tube S 3 And MOSFET power tube S 4 (ii) a The input DC power supply V in 2 positive pole and input DC power supply V in 1 is connected with the negative pole of the power supply and is input with a direct current power supply V in 2 negative pole connected to one end of input inductor L2, and the other end of input inductor L2 connected to MOSFET power transistor S 3 Source electrode of and MOSFET power tube S 4 Drain electrode of (2), diode D 3 And diode D 4 Cathode of (2), diode D 3 Cathode of the power supply is connected with an input direct current power supply V in 2 positive electrode, MOSFET power transistor S 3 Is connected with an input direct current power supply V in 2 positive electrode, MOSFET power transistor S 3 Source-connected diode D 4 Cathode of the capacitor is connected with an output capacitor C 2 Negative electrode of (1), output capacitor C 2 Positive pole of the DC power supply V in 2 is a positive electrode;
the full-control inverter INV comprises a full-control inverter bridge and a filter inductor L f And a filter capacitor C f (ii) a Output capacitor C 1 And output capacitor C 2 The input end of the full-control inverter bridge is connected in series; of fully-controlled inverter bridgesPositive output connected with inductor L f The output of the negative pole of the full-control inverter bridge is connected with the common ground at the AC side; filter capacitor C f And a load resistance R L Connected in parallel and one end of which is connected with an inductor L f And the other end of the anode is connected to a common ground on the AC side.
2. The bi-directional half-bridge dc-to-ac converter grid-connected inverter of claim 1, wherein the full-controlled inverter bridge is composed of four MOSFET power transistors S ap 、S an 、S bp 、S bn And (4) forming.
3. The bi-directional half-bridge dc converter grid-connected inverter of claim 1, wherein the relationship between the double frequency power of the bi-directional half-bridge dc converter grid-connected inverter satisfies:
wherein, P C1_2ω Is a capacitor C 1 Above double frequency ripple power, P C2_2ω Is a capacitor C 2 Above double frequency ripple power, P o-2ω Is the double frequency ripple power, P, of the AC side of the inverter in_2ω Is the double frequency ripple power of the input DC power supply.
4. The bi-directional half-bridge dc converter grid-connected inverter of claim 1, wherein the output capacitor C 1 And output capacitor C 2 The capacitance value C of the capacitor meets the following requirements:
in the formula I bus_2ω_m Is the amplitude of a double frequency component of the DC bus current, V bus Is the DC component of the DC bus voltage, ω is the AC side fundamental angular frequency, V in Is a single pairAn input voltage to the half-bridge dc converter module.
5. A ripple control method of a bidirectional half-bridge DC converter grid-connected inverter according to claims 1 to 4, characterized by comprising:
by means of a capacitor C 1 And C 2 The double-frequency ripple energy in the buffer system is controlled to form a complementary state by controlling the capacitor voltage ripple, so that the direct current bus capacitor voltage ripple is reduced;
the control signal of the power tube consists of a complementary component and a compensation component, the complementary component is generated by a controlled target complementary voltage ripple, and a direct-current working point voltage stabilizing loop is added to generate the compensation component;
the bidirectional half-bridge direct current converter module automatically switches the working state of voltage boosting or voltage reduction according to the direction of output current in a frequency doubling period.
6. The ripple control method of an active suppression low frequency ripple cascaded bidirectional half-bridge DC converter grid-connected inverter according to claim 5,
two single-voltage closed-loop structures are adopted to control the direct current working point voltage:
first single voltage closed loop: real-time sampling output capacitor C 1 Is measured by the instantaneous voltage v C1 Filtering out ripple signals with fixed frequency after passing through a frequency doubling trap to obtain direct current component V C1 ，V C1 Half of the steady-state average value of the DC bus voltage
Subtracted as a voltage loop regulator G v1 I, the output current judging module 1 monitors i in real time out1 If i is out1 >0, judging the output of the module to be 1; if i out1 <0, judging that the output of the module is 0; judging module output result and voltage ring regulator G v1 The output of the power transistor is multiplied by a multiplier to obtain the MOSFET power transistor S 1 DC working point compensating duty ratio signal
The output result of the judgment module is inverted and then is connected with a voltage loop regulator G v1 The output of the power transistor is multiplied by a multiplier to obtain the MOSFET power transistor S 2 DC working point compensating duty ratio signal
Second single voltage closed loop: real-time sampling output capacitor C 2 Is measured by the instantaneous voltage v C2 Filtering out ripple signals with fixed frequency after passing through a frequency doubling trap to obtain direct current component V C2 ，V C2 Half of the steady-state average value of the DC bus voltage
Subtracted as a voltage loop regulator G v2 I, the output current judging module 3 monitors in real time out2 If i is out2 >0, judging the output of the module to be 1; if i out2 <0, judging that the output of the module is 0; judging module output result and voltage ring regulator G v1 The output of the power transistor is multiplied by a multiplier to obtain the MOSFET power transistor S 3 DC working point compensating duty ratio signal
The output result of the judgment module is inverted and then is connected with a voltage loop regulator G v2 The output of the power transistor is multiplied by a multiplier to obtain the MOSFET power transistor S 4 DC working point compensating duty ratio signal
7. The ripple control method of an active suppression low frequency ripple cascaded bidirectional half-bridge DC converter grid-connected inverter according to claim 6,
the complementary control of the capacitor voltage ripple is as follows: by calculating the complementary output capacitor voltageOutput current i to the first and second bidirectional half-bridge DC converter modules BHDC1 and BHDC2 out1 、i out2 Obtaining the control quantity d according to the circuit relation of the bidirectional half-bridge DC converter 1 、d 2 、d 3 、d 4 Compensating duty ratio signal of control quantity and corresponding DC working point
Adding to obtain final duty ratio signal, and generating switching signal by using modulation wave to realize MOSFET power tube S 1 、S 2 、S 3 、S 4 And (4) controlling.
8. The ripple control method of the active suppression low-frequency ripple cascaded bidirectional half-bridge direct current converter grid-connected inverter according to claim 7, wherein the expression of the output capacitor voltage is as follows:
wherein v is C1 、v C2 Representing the output capacitance C 1 、C 2 Instantaneous voltage of V bus Representing the DC component of the DC bus voltage, I bus_2ω_m Representing the amplitude of a double frequency component of the DC bus current, and C representing an output capacitor C 1 、C 2 ω represents the power frequency angular frequency of the ac side inverter output ac flow.
9. The ripple control method of an active suppression low frequency ripple cascaded bidirectional half-bridge DC converter grid-connected inverter according to claim 7, wherein the output current i is out1 、i out2 The calculation formula of (c) is:
in the formula, wherein I bus_2ω_m Is the amplitude of the double frequency current of the inverter, omega represents the power frequency angular frequency of the output alternating current of the inverter at the alternating current side, C represents the output capacitor C 1 、C 2 Volume value of (V) bus Representing the dc component of the dc bus voltage.
10. The ripple control method of an active suppression low frequency ripple cascaded bidirectional half-bridge DC converter grid-connected inverter according to claim 6, wherein the ripple control method is implemented in a capacitor C 1 Capacitor C 2 Under the condition that the capacitance value is the same as the voltage of the direct current working point, the MOSFET power tube S 1 MOSFET power tube S 2 MOSFET power tube S 3 MOSFET power tube S 4 The control signal calculation formula is as follows:
wherein d is 1 、d 2 、d 3 、d 4 Respectively representing MOSFET power tubes S 1 、S 2 、S 3 、S 4 Duty cycle, v C1 Representing the output capacitance C 1 Instantaneous voltage of v C2 Representative output capacitance C 2 Instantaneous voltage of T s Is the switching period of the switching tube, i out1 、i out2 Output currents, V, of the first and second bi-directional half-bridge DC converter modules BHDC1 and BHDC2, respectively in 1、V in 2 are the input voltages of the first and second bi-directional half-bridge dc converter modules BHDC1 and BHDC2, respectively.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116683786A (en) * | 2023-06-06 | 2023-09-01 | 浙江大学 | Single-phase five-level grid-connected inverter and active power decoupling control strategy |
| CN116760270A (en) * | 2023-08-11 | 2023-09-15 | 西南交通大学 | Boost-PFC converter for stabilizing voltage secondary ripple |
| WO2024082715A1 (en) * | 2022-10-18 | 2024-04-25 | 华为数字能源技术有限公司 | Power conversion system and ripple current suppression method therefor |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20160122351A (en) * | 2015-04-13 | 2016-10-24 | 엘에스산전 주식회사 | Force discharging device of inverter for electric vehicle |
| WO2017107401A1 (en) * | 2015-12-23 | 2017-06-29 | 厦门科华恒盛股份有限公司 | Direct-current bus voltage ripple compensation method and photovoltaic inverter |
| CN110474540A (en) * | 2019-08-25 | 2019-11-19 | 南京理工大学 | Current Sensorless current-sharing control method based on two module bi-directional half bridge DC converter crisscross parallels |
| CN112234808A (en) * | 2020-09-09 | 2021-01-15 | 西安交通大学 | Double-frequency ripple suppression circuit and suppression method of single-phase inverter |
| CN113726210A (en) * | 2021-07-30 | 2021-11-30 | 西安交通大学 | Two-stage double-active-bridge grid-connected inverter direct-current bus low-frequency ripple suppression circuit and method |
-
2022
- 2022-07-12 CN CN202210817010.9A patent/CN115051565A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20160122351A (en) * | 2015-04-13 | 2016-10-24 | 엘에스산전 주식회사 | Force discharging device of inverter for electric vehicle |
| WO2017107401A1 (en) * | 2015-12-23 | 2017-06-29 | 厦门科华恒盛股份有限公司 | Direct-current bus voltage ripple compensation method and photovoltaic inverter |
| CN110474540A (en) * | 2019-08-25 | 2019-11-19 | 南京理工大学 | Current Sensorless current-sharing control method based on two module bi-directional half bridge DC converter crisscross parallels |
| CN112234808A (en) * | 2020-09-09 | 2021-01-15 | 西安交通大学 | Double-frequency ripple suppression circuit and suppression method of single-phase inverter |
| CN113726210A (en) * | 2021-07-30 | 2021-11-30 | 西安交通大学 | Two-stage double-active-bridge grid-connected inverter direct-current bus low-frequency ripple suppression circuit and method |
Non-Patent Citations (2)
| Title |
|---|
| 袁义生;张育源;钟青峰;胡根连;: "两级式逆变器母线电压二次纹波分析及抑制", 电源学报, no. 01, 24 August 2016 (2016-08-24) * |
| 黄登;蒋俊;: "双半桥双向DC/DC变换器分析和控制", 电工技术, no. 17, 10 September 2020 (2020-09-10) * |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2024082715A1 (en) * | 2022-10-18 | 2024-04-25 | 华为数字能源技术有限公司 | Power conversion system and ripple current suppression method therefor |
| CN116683786A (en) * | 2023-06-06 | 2023-09-01 | 浙江大学 | Single-phase five-level grid-connected inverter and active power decoupling control strategy |
| CN116683786B (en) * | 2023-06-06 | 2024-02-09 | 浙江大学 | Single-phase five-level grid-connected inverter and active power decoupling control strategy |
| CN116760270A (en) * | 2023-08-11 | 2023-09-15 | 西南交通大学 | Boost-PFC converter for stabilizing voltage secondary ripple |
| CN116760270B (en) * | 2023-08-11 | 2023-11-07 | 西南交通大学 | Boost-PFC converter for stabilizing voltage secondary ripple |
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