TWI832424B - Two-way converter - Google Patents

Abstract

The present invention relates to a two-way converter, which is composed of an isolated step-down converter and a non-isolated step-down converter, and can be output and input from the first input/output and the second output/input respectively, which can not only reduce the number of components used in the converter, but also reduce the development cost of the converter, and increase the practical efficiency in its overall implementation.

Description

bidirectional converter

The present invention relates to a bidirectional converter, particularly a bidirectional converter that can not only reduce the number of components used in the converter, but also reduce the development cost of the converter and increase its practical performance in its overall implementation.

Press, with the rapid development of modern science and technology and economy, various convenient and practical electronic products continue to be introduced and are widely used in people's daily lives. Since the industrial revolution, a large number of heavy industries and petrochemical industries have developed rapidly in science and technology, and in production In the process of development, a large amount of petrochemical energy such as oil and natural gas is used that pollutes the environment. Burning a large amount of petrochemical energy will produce carbon dioxide that pollutes the air. This will cause holes in the ozone layer in the atmosphere, which will indirectly cause serious air pollution and Global warming and other issues; therefore, in 1997, in order to solve the exhaust pollution caused by heavy industry, various countries passed the Kyoto Protocol in Tokyo, Japan, to regulate that major industrial countries must reduce greenhouse gas emissions. Nowadays, environmental awareness and legal regulations are gradually receiving more attention. When developing electronic technology, we must also pay attention to environmental issues, because the low conversion efficiency of electronic products will also cause energy of waste. Therefore, developing circuit conversion efficiency that can be effectively improved has become the focus of current scientific and technological development. Therefore, in the field of power electronics, effectively improving circuit conversion efficiency is an important research goal.

At present, the DC-to-DC converter is the most widely used type of converter, and it is also the type of converter with the most diverse structural changes. It is often used in battery energy storage systems, DC power supplies, various electronic products, etc.; this converter The characteristic is that both the input power supply and the load terminal are DC, and the current flows from the input terminal to the output terminal, so all components in the circuit are unidirectional. In DC circuits, the duty cycle of the trigger signal of the transistor switch is usually changed to control the rise or fall of the output voltage. In a general DC-to-DC converter, the input terminal and the output terminal are electrically connected. relationship, if the input end is grounded and the output end is grounded the same as the input end, the way to electrically isolate the two ends is to use a transformer, and using electrical isolation prevents the current in the circuit from flowing directly into the other side, which can reduce two different The circuits interfere with each other. Although the current cannot flow directly through electrical isolation, the energy can be transferred in other ways. The transformer uses electromagnetic induction to pass the two coils through the iron core. When the current flows through one side, a magnetic field will be generated. The principle of mutual induction through electromagnetism will produce a potential difference in the coil on the other side, which will cause the closed circuit on the other side to generate current and then operate.

This type of converter uses power electronic circuits to convert a fixed DC input voltage into an adjustable DC output of different levels. Therefore, bidirectional buck-boost converters provide the best choice for DC/DC converters that need to operate over a wide output range. Bidirectional buck-boost converters allow bidirectional The method of power transmission to achieve the purpose of power conversion. The bidirectional buck-boost converter can not only reduce the number of components used in the converter, but also reduce the development cost of the converter.

The reason is that, in view of this, the inventor has relied on many years of rich design, development and actual production experience in this related industry, and has further researched and improved the existing structure and deficiencies to provide a bidirectional converter in order to achieve better practical value. By.

The main purpose of the present invention is to provide a bidirectional converter. The converter is mainly composed of an isolated buck-boost converter and a non-isolated buck-boost converter, which can be respectively composed of a first input/output terminal and a non-isolated buck-boost converter. The second output/input terminal performs output and input, which can not only reduce the number of components used in the converter, but also reduce the development cost of the converter, and increase its practical performance in its overall implementation.

1: Converter

11: First input/output

12: Isolated buck-boost converter

C _i : capacitance

N ₁ : Primary side of transformer

L _{m 1} : Primary side magnetizing inductance

S ₁ : first switch

N ₂ : secondary side of transformer

L _{m 2} :Secondary side magnetizing inductance

S ₂ : Second switch

C ₁ : first capacitor

13: Non-isolated buck-boost converter

S ₃ : The third switch

S ₄ : The fourth switch

L _r : inductance

S ₅ : fifth switch

S ₆ : Sixth switch

C ₂ : Second capacitor

14: Second output/input terminal

Figure 1: Circuit diagram of the first usage state of the present invention

Figure 2: Circuit diagram of the second usage state of the present invention

The third figure: the first timing diagram of the present invention

Figure 4: Equivalent linear circuit diagram of the first stage of the present invention [isolated type]

Figure 5: Equivalent linear circuit diagram of the second stage of the present invention [isolated type]

Figure 6: Equivalent linear circuit diagram of the third stage of the present invention [isolated type]

Figure 7: The second timing diagram of the present invention

Figure 8: The third timing diagram of the present invention

Figure 9: Equivalent linear circuit diagram of the first stage of the present invention (non-isolated type)

Figure 10: The second stage equivalent linear circuit diagram of the present invention (non-isolated type)

Figure 11: The fourth timing diagram of the present invention

Figure 12: The driving signal waveform vgs1 of S1 and the real-side waveform diagram of cross-voltage vds1 and vds2 on the switches S1 and S2 of the present invention [isolated D=0.2]

Figure 13: Real-side waveform diagram of signal vds and current ids of switches S1 and S2 of the present invention [isolated D=0.2]

Figure 14: Real-side waveform diagram of the voltage and current at both ends of the primary and secondary sides of the transformer of the present invention [isolated D=0.2]

Figure 15: The driving signal waveform vgs1 of S1 and the real-side waveform diagram of cross-voltage vds1 and vds2 on the S1 and S2 switches of the present invention [isolated D=0.7]

Figure 16: Real-side waveform diagram of signal vds and current ids of switches S1 and S2 of the present invention [isolated D=0.7]

Figure 17: Real-side waveform diagram of the voltage and current at both ends of the primary side and secondary side of the transformer of the present invention [isolated D=0.7]

Figure 18: Real-side waveform diagrams of drive signal waveforms vgs4 and vgs6 of switches S4 and S6 of the present invention [non-isolated D=0.2]

Figure 19: Signal v _{ds 4} terminal and current i _{ds 4} real-side waveform diagram of the fourth switch S ₄ of the present invention [non-isolated D=0.2]

Figure 20: Signal v _{ds 6} terminal and current i _{ds 6} real-side waveform diagram of the sixth switch S ₆ of the present invention [non-isolated D=0.2]

Figure 21: The real-side waveform diagram of the voltage v _Lr and current i _Lr of the inductor L _r of the present invention [non-isolated D=0.2]

Figure 22: The signal v _{ds 5} terminal and the current i _{ds 5} real-side waveform diagram of the fifth switch S ₅ of the present invention [non-isolated D=0.2]

Figure 23: Signal v _{ds 3} terminal and current i _{ds 3} real-side waveform diagram of the third switch S ₃ of the present invention [non-isolated D=0.2]

Figure 24: Real-side waveform diagram of the driving signal waveforms v _gs 4 and v _{gs 6} of the switches S ₄ and S ₆ of the present invention [non-isolated D=0.7]

Figure 25: Signal v _{ds 4} terminal and current i _{ds 4} real-side waveform diagram of the fourth switch S ₄ of the present invention [non-isolated D=0.7]

Figure 26: Signal v _{ds 6} terminal and current i _{ds 6} real-side waveform diagram of the sixth switch S ₆ of the present invention [non-isolated D=0.7]

Figure 27: Signal v _{ds 5} terminal and current i _{ds 5} real-side waveform diagram of the fifth switch S ₅ of the present invention [non-isolated D=0.7]

Figure 28: The signal v _{ds 3} terminal and the current i _{ds 3} real-side waveform diagram of the third switch S ₃ of the present invention [non-isolated D=0.7]

In order to have a more complete and clear disclosure of the technical content, the purpose of the invention and the effects achieved by the present invention, they are described in detail below, and please refer to the disclosed drawings and figure numbers: First, please refer to The first figure is a circuit diagram of the first use state of the present invention and the second figure is a circuit diagram of the second use state of the present invention. The converter (1) of the present invention is sequentially provided with first input/output terminals (11) connected in parallel. , an isolated buck-boost converter (12), a first capacitor C ₁ , a non-isolated buck-boost converter (13) and a second output/input terminal (14); where: the first input/output The terminal (11) is connected in parallel with the capacitor C _i of the isolated buck-boost converter (12), and a transformer is connected to the first terminal of the capacitor C _i of the isolated buck-boost converter (12). The first end of the primary side N ₁ , the primary side N ₁ of the transformer forms a primary side magnetizing inductor L _{m 1} , and the second end of the primary side N ₁ of the transformer is connected to the first end of the first switch S ₁ , and the capacitor The second end of C _i is connected to the second end of the first switch S ₁ , and corresponding to the primary side N ₁ of the transformer, there is a secondary side N ₂ of the transformer. The secondary side N ₂ of the transformer forms a secondary side. Magnetizing inductor L _{m 2} , the first end of the secondary side N ₂ of the transformer is connected to the first end of the first capacitor C ₁ , and the second end of the secondary side N ₂ of the transformer is connected to the second switch S ₂ The first end of the second switch S ₂ is connected to the second end of the first capacitor C ₁ , and the non-isolated buck-boost converter (13) is connected to the first capacitor C ₁ The first end of the third switch S3 is connected to the first end _of the third switch _S3 , and the second end of _the third switch S3 is respectively connected to the first end of the fourth switch S4 and the first end of the _inductor Lr . The inductor L The second terminal of _r is respectively connected to the first terminal of the fifth switch S ₅ and the first terminal of the sixth switch S ₆ , and the second terminal of the sixth switch S ₆ is connected to the first terminal of the second capacitor C ₂ , so that The second terminal of the fourth switch S ₄ , the second terminal of the fifth switch S ₅ and the second terminal of the second capacitor C ₂ are all connected to the second terminal of the first capacitor C 1 , and then the second terminal of the fourth switch S 4 is connected to the second terminal of the first capacitor C ₁ . The second capacitor C ₂ is connected in parallel with the second output/input terminal (14).

A simple analysis of the circuit operation principle of the converter (1) shows that when the first input/output terminal (11) performs input and the second output/input terminal (14) performs output, the converter (1) ) when operating in isolated mode; assuming:

1. The circuit operates in a steady state. All voltages and currents are periodic signals, starting and ending at the same position in the switching cycle.

2. Both the transistor switch and the diode are ideal components. The dead time of the switch when switching is zero, there is no leakage current when it is turned on, and there is no forward/reverse voltage drop when it is turned off.

3. The filter capacitor at the output end is ideal with no loss and large capacity, so that the output voltage can be maintained at a fixed value.

4. Do not consider the internal parasitic resistance of the inductor and capacitor and the resistance and leakage inductance of the transformer coil.

155V is input from the first input/output terminal (11), and the duty cycle D is adjusted to 0.2~0.7. When the duty cycle is 0.2, the system operates in DCM [Discontinuous Conduction Mode], and the duty cycle D is adjusted to 0.2~0.7. At 0.7, the operation is in CCM [Continuous Conduction Mode, continuous conduction mode].

When the duty cycle is 0.2, depending on whether each switch is switched on or off, the The action of the converter (1) in a switching cycle is divided into three stages as follows; for its timing and waveform, please refer to the first timing diagram of the present invention in the third figure:

t<t ₁〕：〔第一開關S ₁：ON、第二開關S ₂：OFF、第三開關S ₃：ON、第四開關S ₄：OFF、第五開關S ₅：ON、第六開關S ₆：OFF〕：請再一併參閱第四圖本發明之第一階段等效線性電路圖〔隔離式〕所示，在工作模式一中，該第一開關S ₁為ON，將該第二開關S ₂操作為飛輪二極體為OFF，使得當該第一開關S ₁導通時，該變壓器一次側N ₁上兩端跨壓會等同於輸入端電壓，得V _in =v ₁， (1) Working mode one [ t ₀

t < t ₁ ]: [First switch S ₁ : ON, second switch S ₂ : OFF, third switch S ₃ : ON, fourth switch S ₄ : OFF, fifth switch S ₅ : ON, sixth switch S ₆ : OFF]: Please refer to the fourth figure for the first stage equivalent linear circuit diagram of the present invention (isolated type). In the working mode one, the first switch S 1 is ON, and the second switch S ₁ is turned ON. The switch S ₂ operates so that the flywheel diode is OFF, so that when the first switch S ₁ is turned on, the voltage across the two ends of the primary side N ₁ of the transformer will be equal to the input terminal voltage, and V _in = v ₁ , (1 )

At this time, the current will flow into the primary side magnetizing inductor L _{m 1} of the transformer to store energy. Since the polarity of the primary side and the secondary side is opposite, the secondary side voltage v ₂ can be obtained as

At this time, the voltage across the flywheel diode of the second switch S ₂ is V _{S 2 =} v ₂ + Vo , (3)

The flywheel diode of the second switch S ₂ is reverse-biased and opened, and the first capacitor C ₁ provides the energy required by the load R of the second output/input terminal (14). When the first switch S ₁ is turned on, the primary side magnetizing inductor L _{m 1} of the transformer continues to store energy, so the primary side current i _{Lm 1} rises linearly. When t = t ₁ , the first switch S ₁ will Switch to OFF to proceed to the next stage.

t<t ₂〕：〔第一開關S ₁：OFF、第二開關S ₂：ON、第三開關S ₃：OFF、第四開關S ₄：ON、第五開關S ₅：OFF、第六開關S ₆：ON〕：請再一併參閱第五圖本發明之第二階段等效線性電路圖〔隔離式〕所示，在工作模式二中，該第一開關S ₁為OFF，將該第二開關S ₂、該第四開關S ₄、該第六開關S ₆操作為飛輪二極體為ON，此時因t=t ₁，該第一開關S ₁切換至OFF，使變壓器一次側電流i _Lm1與鐵心磁通減少，且電流從一次側打點端流出，而二次側電流打點端流入使飛輪二極體電流為正且導通，此時二次側電壓為v ₂=-V _o ， (4) Working mode two [ t ₁

t < t ₂ ]: [First switch S ₁ : OFF, second switch S ₂ : ON, third switch S ₃ : OFF, fourth switch S ₄ : ON, fifth switch S ₅ : OFF, sixth switch S ₆ : ON]: Please refer to Figure 5 for the second stage equivalent linear circuit diagram of the present invention (isolated type). In the second operating mode, the first switch S ₁ is OFF, turning the second The switch S ₂ , the fourth switch S ₄ , and the sixth switch S ₆ operate so that the flywheel diode is ON. At this time, because t = t ₁ , the first switch S ₁ is switched to OFF, causing the primary side current of the transformer i _{Lm 1} and the core magnetic flux decrease, and the current flows out from the primary side terminal, and the secondary side current terminal flows in, making the flywheel diode current positive and conductive. At this time, the secondary side voltage is v ₂ =- V _o , (4)

The secondary side voltage will be converted back to the primary side, and we can get

t<t ₃〕：〔第一開關S ₁：OFF、第二開關S ₂：OFF、第三開關S ₃：OFF、第四開關S ₄：ON、第五開關S ₅：OFF、第六開關S ₆：ON〕：請再一併參閱第六圖本發明之第三階段等效線性電路圖〔隔離式〕所示，在工作模式三中，該第一開關S ₁為OFF，將該第二開關S ₂操作為飛輪二極體為OFF，此時開關保持截止狀態，且該變壓器之一次側磁化電感L _m1的能量已經完全釋放，即i ₁=0也使i ₂=0，因此該第二開關S ₂操作為飛輪二極體也成截止狀態。而該第一電容C ₁提供該第二輸出/入端(14)之負載R所需消耗的 能量。 Working mode three [ t ₂

t < t ₃ ]: [First switch S ₁ : OFF, second switch S ₂ : OFF, third switch S ₃ : OFF, fourth switch S ₄ : ON, fifth switch S ₅ : OFF, sixth switch S ₆ : ON]: Please refer to Figure 6 for the third stage equivalent linear circuit diagram of the present invention (isolated type). In the operating mode 3, the first switch S ₁ is OFF, and the second switch S 1 is turned OFF. The switch S ₂ is operated such that the flywheel diode is OFF. At this time, the switch remains in the off state, and the energy of the primary side magnetizing inductor L _{m 1} of the transformer has been completely released, that is, i ₁ =0 and i ₂ =0, so the The second switch S2 is operated so that _the flywheel diode is also in a cut-off state. The first capacitor C ₁ provides the energy required by the load R of the second output/input terminal (14).

When the duty cycle is 0.7, depending on whether each switch is switched on or not, the action of the converter (1) in one switching cycle can be divided into two stages. Please refer to Figure 7 for the timing and waveform. As shown in the second timing diagram of the present invention, these two stages are respectively the same as the working mode one and the working mode two when the working cycle is 0.2. The only difference is that the operation is in CCM (Continuous Conduction Mode, continuous conduction mode). This will not be described in detail.

In addition, when the second output/input terminal (14) performs input and the first input/output terminal (11) performs output, so that the converter (1) operates in a non-isolated mode; assume:

1. The circuit operates in steady state.

2. All components in the circuit are in an ideal state, and the dead time when the switch is switched is zero.

3. Assuming the output voltage is fixed, the capacitor needs to be quite large.

4. The inductor current is CCM [continuous conduction mode].

5. The switching period is T , the switch on-time is DT , and the switch off-time is (1- D ) T.

48V is input from the second output/input terminal (14), and the duty cycle D is adjusted to 0.2~0.7, both operating in CCM (Continuous Conduction Mode, continuous conduction mode).

When the duty cycle is 0.2, depending on whether each switch is switched on or off, the The action of the converter (1) in a switching cycle is divided into two stages as follows; its timing and waveforms are shown in Figure 8 and the third timing diagram of the present invention:

t<t ₁〕：〔第一開關S ₁：OFF、第二開關S ₂：ON、第三開關S ₃：OFF、第四開關S ₄：ON、第五開關S ₅：OFF、第六開關S ₆：ON〕：請再一併參閱第九圖本發明之第一階段等效線性電路圖〔非隔離式〕所示，在工作模式一中，該第四開關S ₄及該第六開關S ₆為導通狀態，將該第三開關S ₃及該第五開關S ₅操作為飛輪二極體因逆向偏壓而呈截止狀態，此時該電感L _r 之電感電壓v _Lr 為正，而電流流入該電感L _r 進行儲能，因此電感電流i _Lr 呈現線性上升，此時該第一輸入/出端(11)所需的能量由該第一電容C ₁提供。此動作模式下的電壓電流關係方程式為：

Working mode one [ t ₀

t < t ₁ ]: [First switch S ₁ : OFF, second switch S ₂ : ON, third switch S ₃ : OFF, fourth switch S ₄ : ON, fifth switch S ₅ : OFF, sixth switch S ₆ : ON]: Please refer to Figure 9 for the first stage equivalent linear circuit diagram of the present invention (non-isolated type). In the operating mode one, the fourth switch S ₄ and the sixth switch S ₆ is in the on state, and the third switch S ₃ and the fifth switch S ₅ are operated so that the flywheel diodes are in a cut-off state due to reverse bias. At this time, the inductor voltage v _Lr of the inductor L _r is positive, and the current Energy flows into the inductor L _r to store energy, so the inductor current i _Lr rises linearly. At this time, the energy required by the first input/output terminal (11) is provided by the first capacitor C ₁ . The voltage-current relationship equation in this action mode is:

The change amount Δi _Lr when the inductor current i _Lr rises is

t<t ₂〕：〔第一開關S ₁：ON、第二開關S ₂：OFF、第三開關S ₃：ON、第四開關S ₄：OFF、第五開關S ₅：ON、第六開關S ₆：OFF〕：請再一併參閱第十圖本發明之第二階段等效線性電路圖〔非隔離式〕所示，在工作模式二中，該第四開關S ₄及該第六開關S ₆呈截止狀態，此時該第三開關S ₃及該第五開關S ₅操作為飛輪二極體會有電流流入而順向偏壓呈導通狀態，而該電感L _r 因 沒能量持續供給而開始釋放儲存的能量，因此電感電壓v _Lr 為負值，而電感電流i _Lr 呈現線性下降，此時該第一輸入/出端(11)所需的能量則由電感電流i _Lr 提供。此動作模式下的電壓電流關係方程式為：

Working mode two [ t ₁

t < t ₂ ]: [First switch S ₁ : ON, second switch S ₂ : OFF, third switch S ₃ : ON, fourth switch S ₄ : OFF, fifth switch S ₅ : ON, sixth switch S ₆ : OFF]: Please refer to Figure 10 for the second stage equivalent linear circuit diagram of the present invention (non-isolated type). In the operating mode 2, the fourth switch S ₄ and the sixth switch S ₆ is in a cut-off state. At this time, the third switch S ₃ and the fifth switch S ₅ are operated so that the flywheel diode will have current flowing in and the forward bias voltage will be in a conductive state, and the inductor L _r will start due to no continuous supply of energy. The stored energy is released, so the inductor voltage v _Lr is negative and the inductor current i _Lr decreases linearly. At this time, the energy required by the first input/output terminal (11) is provided by the inductor current i _Lr . The voltage-current relationship equation in this action mode is:

The change amount Δi _Lr when the inductor current i _Lr decreases is

When the duty cycle is 0.7, depending on whether each switch is switched on or not, the action of the converter (1) in one switching cycle can also be divided into two stages. Please refer to Chapter 10 for the timing and waveform. As shown in the fourth timing diagram of the present invention, these two stages are respectively the same as the working mode one and the working mode two when the working cycle is 0.2, and will not be described in detail here.

The switching frequency of the converter (1) is operated at 100kHz, and the isolated buck-boost converter (12) and the non-isolated buck-boost converter (13) are tested respectively; the isolated buck-boost converter (13) The converter (12) has the following modes: discontinuous conduction mode [DCM], duty cycle operation D at 0.2, input V _in =155 V from the first input/output terminal (11), input from the second output/input Terminal (14) outputs V _o =32.6 V , with continuous conduction mode [CCM], duty cycle D operating at 0.7, input from the first input/output terminal (11) V _in =155 V , and input from the second The output/input terminal (14) outputs V _o =120.55 V.

The transformer turns ratio N ₁ : N ₂ of the isolated buck-boost converter (12) is designed to be a ratio of 3: 1 for winding. Due to the limited influence of the winding frame of the transformer, the final measurement is carried out after winding. The primary side magnetizing inductance L _{m 1} was measured to be 542.54 μ H , while the secondary side magnetizing inductance L _{m 2} was 61.41 μ H.

The formula for the minimum value of the primary side magnetizing inductance L _{m 1} if it needs to operate in the continuous current mode is:

Please refer to Table 1 below for the parameters of each component. When the duty cycle [Duty ratio] is 0.2

When the duty cycle [Duty ratio] is 0.7

After derivation from equations (11) and (12), we can get the minimum value of the primary side magnetizing inductance L _{m 1} required if the circuit is to operate in the continuous current mode, and the actual winding and measured data of the primary side magnetizing inductance L _{m 1} is 542.54μ H , so it can be inferred that when the duty cycle [Duty ratio] operates at 0.2, the circuit operates in discontinuous current mode, and when the duty cycle [Duty ratio] operates at 0.7, the circuit operates in continuous current mode.

In continuous current mode, the output voltage formula when the duty cycle [Duty ratio] operates at 0.7 is:

In discontinuous current mode, the output voltage formula when the duty cycle [Duty ratio] operates at 0.2 is:

When input from the first input/output terminal (11), since the duty cycle D operates between 0.2 and 0.7, the actions are roughly similar and both are in buck mode. When the duty cycle D operates at 0.2, the first input The /output terminal (11) inputs V _in =155 V , the second output /input terminal (14) outputs V _o =32.6 V , and the actual output voltage is V _o =34 V. At this time, the circuit is in discontinuous conduction mode.

Please refer to Figure 12 again for the driving signal waveform v _{gs 1} of S ₁ of the present invention and the real-side waveform diagram of the cross-voltage v _{ds 1} and v _{ds 2} on the switches S ₁ and S ₂ [isolated D=0.2] As shown in the figure, you can observe the on or off state in the same operating mode when the drive signal is sent to the switch. Please refer to Figure 13 again. The signal v _ds and current i _ds of the switches S ₁ and S ₂ of the present invention are shown in the real-side waveform diagram [isolated D=0.2]. When the first switch S ₁ is turned on, the input The current will flow through the primary side magnetized inductor L _{m 1} and begin to store energy. When the voltage on the switch is equal to the input voltage, no current will pass through and the energy storage of the inductor will stop. The second switch S ₂ will be turned on when switching to the next working stage. At this time, the inductor will start to discharge. Since this circuit operates in DCM, the inductor current will drop to zero and the switches will be in the off state. Please refer to Figure 14 again, which shows the real-side waveform diagram of the voltage and current at both ends of the primary side and secondary side of the transformer of the present invention [isolated D=0.2]. When the inductor voltage is positive, the inductor current will be It rises linearly and stores energy. When the inductor voltage is negative, the inductor current decreases linearly and gradually releases energy. The actual input voltage is 153.4V, the input current is 0.06A, the input power is 9.3W, the output voltage is 34V, the output current is 0.27A, the output power is 9.18W, and the efficiency is 98.71%.

When the duty cycle D operates at 0.7, the first input/output terminal (11) inputs V _in =155 V , the second output/input terminal (14) outputs V _o =120.55 V , and the actual output voltage is V _o =118.7 V , at this time the circuit is in continuous conduction mode.

Please refer to Figure 15 again for the driving signal waveform v _{gs 1} of S ₁ of the present invention and the real-side waveform diagram of the cross-voltage v _{ds 1} and v _{ds 2} on the switches S ₁ and S ₂ [isolated D=0.7] As shown in the figure, it can be observed that when the driving signal is sent to the switch, it is in the on or off state in the same working mode. Please refer to Figure 16 again. The signal v _ds and current i _ds of the switches S ₁ and S ₂ of the present invention are shown in the real-side waveform diagram [isolated D=0.7]. When the first switch S ₁ is turned on, the input The current will flow through the primary side magnetized inductor L _{m 1} and begin to store energy. When the voltage on the switch is equal to the input voltage, no current will pass through and the energy storage of the inductor will stop. The second switch S ₂ will be turned on when switching to the next working stage. At this point the inductor will begin to discharge. Please refer to Figure 17 again for the real-side waveform diagram of the voltage and current at both ends of the primary and secondary sides of the transformer of the present invention [isolated D=0.7]. When the inductor voltage is positive, the inductor current will be It rises linearly and stores energy. When the inductor voltage is negative, the inductor current decreases linearly and gradually releases energy. The actual input voltage is 153.2V, the input current is 0.81A, the input power is 123.86W, the output voltage is 118.7V, the output current is 0.99A, the output power is 117.42W, and the efficiency is 94.8%.

In addition, the non-isolated buck-boost converter (13) has the following mode: the duty cycle D operates at 0.2, the second output/input terminal (14) inputs V _in =48 V , and the first input/ The output terminal (11) performs an input of V _o =16 V , and the duty cycle D operates at 0.7. The second output/input terminal (14) performs an input of V _in =48 V , and the first input/output terminal (11) performs an input of V in =48 V. Enter V _o =144 V.

Please also refer to Table 2 below:

When the duty cycle D operates at 0.2, the second output/input terminal (14) inputs V _in =48 V , the first input/output terminal (11) outputs V _o =16 V , and the actual output voltage is V _o =17.26 V

Please refer to Figure 18 again. The driving signal waveforms v _{gs 4} and v _{gs 6} of the switches S ₄ and S ₆ of the present invention are shown in the real-side waveform diagram [non-isolated D=0.2], which is mainly to provide the switch with a The drive signal is turned on or off. Please refer to Figure 19 for the signal v _{ds 4 terminal} of the fourth switch S 4 of the present invention and the real-side waveform diagram of the current i _{ds 4} (non-isolated D=0.2) and Figure 20 for the sixth of the present invention. As shown in the real-side waveform diagram of the signal v _{ds 6} terminal of switch S 6 and the current i _{ds 6} [non-isolated D=0.2], when the fourth switch S _{4 and} the sixth switch S ₆ are turned on, the input current will flow through the inductor L _r starts to store energy. When the voltage on the switch is equal to the input voltage, no current passes through and the energy storage in the inductor stops. Please refer to Figure 21 again. The voltage v _Lr and current i _Lr of the inductor L _r of the present invention are shown in the real-side waveform diagram [non-isolated D=0.2]. When the inductor voltage is positive, the inductor current will be It rises linearly and stores energy. When the inductor voltage is negative, the inductor current decreases linearly and gradually releases energy. Please refer to Figure 22 again for the signal v _{ds 5} terminal of the fifth switch S ₅ of the present invention and the real-side waveform diagram of the current i _{ds 5} (non-isolated D=0.2) and Figure 23 of the present invention. As shown in the real-side waveform diagram of the signal v _{ds 3} terminal of the third switch S ₃ and the current i _{ds 3} [non-isolated D=0.2], when the switch voltage shows a negative output voltage, the current will not flow through the parasitic diode inside the switch. body, and when the switch voltage is zero, it will become a conductive state, and the current will flow through the third switch S ₃ at this time. The actual input voltage is 48.24V, the input current is 0.05A, the input power is 2.48W, the output voltage is 17.26V, the output current is 0.13A, the output power is 2.32W, and the efficiency is 93.5%.

When the duty cycle D operates at 0.7, the second output/input terminal (14) inputs V _in =48 V , the first input/output terminal (11) outputs V _o =140 V , and the actual output voltage is V _o =133.8 V

Please refer to Figure 24 again. The driving signal waveforms v _{gs 4} and v _{gs 6} of the switches S ₄ and S ₆ of the present invention are shown in the real-side waveform diagram [non-isolated D=0.7], which is mainly provided to the switch. A drive signal is turned on or off. Please refer to Figure 25 again for the signal v _{ds 4} terminal of the fourth switch S ₄ of the present invention and the real-side waveform diagram of the current i _{ds 4} (non-isolated D=0.7) and Figure 26 of the present invention. As shown in the real-side waveform diagram of the signal v _{ds 6 terminal} of the sixth switch S 6 and the current i _{ds 6} [non-isolated D=0.7], when the fourth switch S ₄ and the sixth switch S ₆ are turned on, the input current will flow through The inductor L _r starts to store energy. When the voltage on the switch is equal to the input voltage, no current passes through and the energy storage in the inductor stops. Please refer to Figure 27 again for the signal v _{ds 5} terminal of the fifth switch S ₅ of the present invention and the real-side waveform diagram of the current i _{ds 5} (non-isolated D=0.7) and Figure 28 of the present invention. As shown in the real-side waveform diagram of the signal v _{ds 3} terminal of the third switch S ₃ and the current i _{ds 3} [non-isolated D=0.7], when the switch voltage shows a negative output voltage, the current will not flow through the parasitic diode inside the switch. body, and when the switch voltage is zero, it will become a conductive state, and the current will flow through the third switch S ₃ at this time. The actual input voltage is 48.42V, the input current is 3.65A, the input power is 176.78W, the output voltage is 133.8V, the output current is 1.13A, the output power is 150.53W, and the efficiency is 85.15%.

From the above, it can be seen from the description of the use of the present invention that compared with the existing technical means, the present invention mainly converts the converter from an isolated buck-boost converter to a non-isolated buck-boost converter. The converter is composed of a first input/output terminal and a second output/input terminal for output and input respectively, which not only reduces the number of components used in the converter, but also reduces the development cost of the converter. Those with more practical functional characteristics during implementation and use.

However, the foregoing embodiments or drawings do not limit the product structure or usage of the present invention. Any appropriate changes or modifications made by those with ordinary knowledge in the technical field shall be regarded as not departing from the patent scope of the present invention.

In summary, the embodiments of the present invention can indeed achieve the expected use effects, and the specific structure disclosed has not only been seen in similar products, but has also not been disclosed before the application, and it fully complies with the provisions of the patent law. If you submit an application for an invention patent in accordance with the law, please review it and grant a patent, it will be very convenient.

1: Converter

11: First input/output

12: Isolated buck-boost converter

C _i : capacitance

N ₁ : Primary side of transformer

L _{m 1} : Primary side magnetizing inductance

S ₁ : first switch

N ₂ : secondary side of transformer

L _{m 2} :Secondary side magnetizing inductance

S ₂ : Second switch

C ₁ : first capacitor

13: Non-isolated buck-boost converter

S ₃ : The third switch

S ₄ : The fourth switch

L _r : inductance

S ₅ : fifth switch

S ₆ : Sixth switch

C ₂ : Second capacitor

14: Second output/input terminal

Claims (3)

A bidirectional converter, which mainly includes a parallel-connected first input/output terminal, an isolated buck-boost converter, a first capacitor, a non-isolated buck-boost converter and a third Two output/input terminals; wherein: the first input/output terminal is connected in parallel with the capacitor of the isolated buck-boost converter, and is connected to the first end of the capacitor of the isolated buck-boost converter. The first end of the primary side of the transformer is connected to the first end of the first switch, and the second end of the capacitor is connected to the second end of the first switch, corresponding to the transformer. The primary side is provided with a secondary side of the transformer, the first end of the secondary side of the transformer is connected to the first end of the first capacitor, and the second end of the secondary side of the transformer is connected to the first end of the second switch. The second terminal of the second switch is connected to the second terminal of the first capacitor, and the non-isolated buck-boost converter has the first terminal of the third switch connected to the first terminal of the first capacitor, The second end of the third switch is respectively connected to the first end of the fourth switch and the first end of the inductor, and the second end of the inductor is respectively connected to the first end of the fifth switch and the first end of the sixth switch. The second terminal of the sixth switch is connected to the first terminal of the second capacitor, so that the second terminal of the fourth switch, the second terminal of the fifth switch and the second terminal of the second capacitor are all connected with the first capacitor. The second terminals are connected to each other, and the second capacitor is connected in parallel with the second output/input terminal. The bidirectional converter according to claim 1, wherein a primary side magnetizing inductor is formed on the primary side of the transformer. The bidirectional converter according to claim 1, wherein a secondary side magnetizing inductor is formed on the secondary side of the transformer.