CN209516935U - Single-input multi-output M switch group DC-DC converter - Google Patents

Abstract

The utility model provides a single-input multiple-output M switch group DC-DC converter. The converter includes a DC input power supply, M‑1 DC loads, M switch groups and coupled inductors. Each switch group is composed of N power switch units connected in series. The utility model circuit has M ports, and can be divided into three ways to connect with one DC power supply and one M-1 DC load. Step-up and step-down, and in the third way, by changing the specific port connected to the DC power supply, step-up and step-down of various voltage levels can be realized. The utility model adopts carrier wave phase-shifting PWM control to control the on and off of the switch tube in the power switch unit, so as to realize the regulation of the load voltage. The utility model is suitable for high-voltage and high-power DC application occasions with single input and multiple outputs.

Description

Single-input multiple-output M-switch group DC-DC converter

technical field

The utility model relates to the field of distributed power generation systems and direct current transmission, in particular to a DC-DC converter with a single-input and multiple-output M switch group.

Background technique

With the development of new energy power generation technology, the increase of DC load and the development of high-voltage DC transmission, the application of DC-DC converters in distributed power generation systems, wind farm energy collection and DC transmission is also growing rapidly. In these fields, how to simultaneously connect multiple DC power sources and DC loads and realize high-voltage and high-power conversion are two important technical issues. For the connection of multiple DC power sources and DC loads, multiple DC-DC converters are traditionally used to connect DC power sources and DC loads to the DC bus, and energy collection and distribution are realized through the DC bus. Using multiple converters undoubtedly increases the System cost and complexity. Therefore, it is imperative to study multi-terminal DC-DC high-voltage converters.

Utility model content

The purpose of this utility model is to overcome above-mentioned deficiencies in the prior art, propose a kind of single-input multiple-output M switch group DC-DC converter.

The purpose of this utility model adopts one of following technical schemes to realize.

A single-input multiple-output M switch group DC-DC converter includes a DC input power supply U _dc , M-1 DC loads (R ₁ , R ₂ ,..., R _M-1 ), M switch groups (A ₁ , A ₂ ,..., A _M ) and coupled inductance (L _p : L _s ) are connected in series; the jth switch group A _j is composed of N power units (SM _Aj1 , SM _Aj2 ,..., SM _AjN ) in series, j's The value is from 1 to M, and N is a positive integer; the upper end of the jth switch group A _j constitutes the jth port T _j of the converter, j takes a value from 1 to M-1, and the lower end of the M-1th switch group constitutes the port T _M , the lower end of the Mth switch group is connected to the ground point n.

Further, the voltage U 1 of the first port T ₁ of the single-input multiple-output M switch group DC-DC converter, the voltage U ₂ of the _second port T ₂ , ..., the voltage U of the M-1th port T _{M-1 M-1} , the voltage U _M of the _Mth port _TM satisfies U ₁ >U ₂ >…>UM _-1 >UM .

Further, there are three different connection modes for the DC input power supply U _dc , M-1 DC loads (R ₁ , R ₂ , ..., R _M-1 ) and _M ports (T ₁ , T ₂ , ..., TM ) . The first method: the _first port T1 is connected to the positive pole of the _DC input power supply _Udc , the negative pole of the DC input power supply Udc is connected to the ground n, and the _second port T2 to the Mth port T _M are respectively connected to the M-1 direct current One end of the load (R ₁ , R ₂ , ..., R _M -1 ) is connected, and the other end of the M-1 DC load (R ₁ , R ₂ , ..., R _M-1 ) is connected to the ground to realize the step-down function ; The second way: the positive pole of the _DC input power supply Udc is connected to the M port, the negative pole of the _DC input power supply Udc is connected to the ground n, and the first port to the M-1th port are respectively connected to the M-1 road DC load (R ₁ , R ₂ ,..., R _M-1 ) are connected at one end, and the other end of the M-1 DC load (R ₁ , R ₂ ,..., R _M-1 ) is connected to the ground to realize the boost function; the third One way: the positive pole of the DC input power supply U _dc is connected to the jth port (j is 2 to M-1), the negative pole of the DC input power supply U _dc is connected to the ground n, and the remaining M-1 ports are respectively connected to M-1 One end of the DC load (R ₁ , R ₂ ,…, R _M -1 ) is connected, and the other end of the M-1 DC load (R ₁ , R ₂ ,…, R _M-1 ) is connected to the ground, and at the same time Buck-boost function, and by changing the specific port connected to the positive pole of the DC power supply, it can realize buck-boost of various voltage levels.

Further, the coupled inductor in the bridge arm can be replaced by two independent inductors with equal values, the upper bridge arm inductor and the lower bridge arm inductor.

Further, the power switch unit includes a first switch tube, a second switch tube, a first diode, a second diode and a capacitor; wherein, the anode of the capacitor is connected to the collector of the second switch tube, the second diode The cathode connection of the second switching tube, the emitter of the second switching tube is connected to the anode of the second diode, the collector of the first switching tube, and the cathode of the first diode, and the emitter of the first switching tube is connected to the first diode The anode of the capacitor is connected to the negative pole of the capacitor; the collector of the first switching tube is used as the first output terminal, and the emitter of the first switching tube is used as the second output terminal.

Further, the second output end of the i-th power switch unit SM _Aji of each switch group is connected to the first output end of the i+1-th power switch unit SM _Aj(i+1) , where the value of i is 1 ~(N-1), j takes a value of 1~M.

The control method of the above-mentioned converter of the present invention is: adopting the carrier phase-shifting PWM technology to control the conduction and shutdown of the switch tubes in the M switch groups (A ₁ , A ₂ ,..., A _M ); for comparison with the modulation wave The triangular carrier u _Ci that generates the control signal of the i-th power switch unit in each switch group is the same, where i takes a value from 1 to N; N carriers (u _C1 , u _C2 ,..., u _CN ) lag behind the phase angle by 360 in turn °/N; M-1 modulation waves u _Ref1 ~ u _RefM-1 adopt DC waves.

In the above control method, the j-th modulation wave u _Refj is compared with the i-th carrier u _Ci through the comparator COMP _ji , when the j-th modulation wave u _Refj is greater than the i-th carrier u _Ci , the comparator COMP _ji outputs a high voltage Ping, when the j-th modulation wave u _Refj is smaller than the i-th carrier u _Ci , the comparator COMP _ji outputs a low level, where the value of j is 1 to M-1. The output of the comparator COMP _1i is used as the control level of the gate of the _first switch tube S1 of the i-th power switch unit SM _A1i of the _first switch group A1, and the output of the comparator COMP _ji is passed through the NOT gate and then ANDed by the comparator COMP _j The output of _-1i passes through the XOR gate together to obtain the control level of the gate of the _first switching transistor S1 of the i-th power switch unit SM _Aji of the _j -th switch group Aj, where: the value of j is 2～ M-1, the output of the comparator COMP _M-1i is passed through the NOT gate to obtain the control level of the gate of the _first switch S1 of the i-th power switch unit SM _AMi of the _M -th switch group AM. The control level of the gate of the _first switch S1 in each power switch unit of each switch group is obtained by inverting the control level of the gate of the _second switch S2 of the power switch unit.

Compared with the prior art, the utility model has the following advantages: the single-input multiple-output M switch group DC-DC converter has the advantages of MMC, and by changing the number N of modules in the switch group, any output voltage can be realized, which is suitable for high-voltage , the application of high-power occasions; compared with the existing DC-DC conversion circuit topology, the DC-DC converter proposed by the utility model can realize M-1 DC output under the condition of one input DC power supply, which greatly improves the The engineering cost is reduced; by selecting different connection methods between the converter port and the DC power supply and DC load, the single-input multiple-output M-switch group DC-DC converter can realize the functions of step-up, step-down, and simultaneous step-up and step-down.

Description of drawings

Fig. 1 is a circuit structure diagram under the second connection mode of a single-input multiple-output M switch group DC-DC converter;

Fig. 2 is a circuit structure diagram of a power unit of a single-input multi-output M switch group DC-DC converter shown in Fig. 1;

Fig. 3 is a structural diagram of the carrier phase-shift PWM control method of the single-input multi-output M switch group DC-DC converter shown in Fig. 1;

Figure 4 shows the modulation wave and carrier waveform of the carrier phase-shift PWM control method adopted by the single-input three-output four-switch group DC-DC converter.

Fig. 5 is a simulation waveform diagram of a single-input three-output four-switch group DC-DC converter.

Detailed ways

In order to further illustrate the content and characteristics of the utility model, the specific implementation of the utility model will be described in detail below in conjunction with the accompanying drawings, but the implementation of the utility model is not limited thereto. It should be pointed out that, if there are any processes or symbols in the following that are not specifically described in detail, those skilled in the art can understand or implement them with reference to the prior art.

Referring to Fig. 1, the single-input multiple-output M switch group DC-DC converter of this embodiment includes a DC input power supply U _dc , M-1 DC loads (R ₁ , R ₂ , ..., R _M-1 ), M switch groups (A ₁ , A ₂ ,..., A _M ) and coupled inductors (L _p : L _s ); each switch group consists of N power units in series, and N is a positive integer. In this example, M is greater than or equal to A positive integer of 4. The lower end of the first switch group A1 is connected to the end with the same name of the primary side L _p of the coupled inductance (L _p : L _s ), and the non-identical end of the primary side L _p of the coupled inductance (L _p : L _s ) is connected to the end of the second switch group A2 The upper end is connected, the lower end of the jth switch group A _j is connected to the upper end of the j+1th switch group A _j+1 , the value of j is 2 to M-2, the lower end of the M-1th switch group A _M-1 is coupled to The inductance (L _p : L _s ) is connected to the end with the same name of the secondary side L _s , and the non-identical end of the secondary side L _s of the coupled inductance (L _p : L _s ) is connected to the upper end of the M switch group A _M , and the M switch group A The lower end of _M is connected to the ground terminal n. In the second connection mode, the first port T ₁ to the M-1th port T _M-1 are respectively connected to one end of M-1 DC loads (R ₁ , R ₂ ,..., R _M-1 ), M- The other end of a DC load (R ₁ , R ₂ , ..., R _M-1 ) is connected to the ground, the _Mth port TM is connected to the positive pole of the DC input power supply U _dc , and the negative pole of the DC input power supply U _dc is connected to the ground n connect. As shown in Figure 1, the second output end of the i-th power switch unit (SM _Aji ) of each switch group is connected to the first output end of the i+1-th power switch unit (SM _Aj(i+1) ) , where i takes a value from 1 to N-1, and j takes a value from 1 to M. The power module in the switch group adopts the half-bridge sub-module shown in Fig. 2 .

As shown in Figure 1, the DC power supply voltage U _dc and the voltages U ₁ ~ U _M-1 at both ends of the M-1 load can be obtained as:

u _Lp =u _Ls (2)

Combine (1)(2) to get

Among them, 2≤j≤M.

According to the carrier phase-shift modulation strategy, select M-1 modulation waves as:

In this example, the single-input three-output four-switch group DC-DC converter adopts the second connection mode, and N=4, U _c =60V, U ₄ =U _dc =48V. In order to obtain three outputs U ₁ =200V, U ₂ =160V, and U ₃ =100V, the modulated waves u _ref1 =0.5, u _ref2 =0, u _ref3 =-13/30 are calculated from formula (4). The waveforms of the obtained modulated wave and carrier wave are shown in Figure 4.

Single-input three-output four-switch group DC-DC converter adopts carrier phase-shift PWM technology to control the conduction and turn-off of switch tubes in M switch groups (A ₁ , A ₂ , A ₃ , A ₄ ); compared with modulation wave The carrier u _Ci of the control signal of the i-th power switch unit in each switch group is the same, where: i ranges from 1 to 4; the four carriers (u _C1 , u _C2 , u _C3 , u _C4 ) lag behind the phase angle by 90 in turn °, 3 channels of DC modulation waves are u _Ref1 =0.5, u _Ref2 =0, u _Ref3 =-13/30. The j-th modulation wave u _Refj is compared with the i-th carrier u _Ci by the j-th comparator. When the j-th modulation wave u _Refj is greater than the i-th carrier u _Ci , the j-th comparator outputs a high level. When the j-th When the modulation wave u _Refj is smaller than the i-th carrier u _Ci , the j-th comparator outputs a low level, and the value of j is 1 to M-1. The output of the comparator COMP _1i is used as the control level of the gate of the _first switch tube S1 of the i-th power switch unit SM _A1i of the _first switch group A1, and the output of the comparator COMP _ji is passed through the NOT gate and then ANDed by the comparator COMP _j The output of _-1i passes through the XOR gate together to obtain the control level of the gate of the _first switching transistor S1 of the i-th power switch unit SM _Aji of the _j -th switch group Aj, wherein: the value of j is 2～ M-1, the output of the comparator COMP _M-1i is passed through the NOT gate to obtain the control level of the gate of the _first switch S1 of the i-th power switch unit SM _AMi of the _M -th switch group AM. The control level of the gate of the _first switch S1 in each power switch unit of each switch group is obtained by inverting the control level of the gate of the _second switch S2 of the power switch unit.

Figure 5 is a simulation waveform diagram of a single-input three-output four-switch group DC-DC converter when N=4 and U _dc =240V. From top to bottom are the first modulation wave u _Ref1 , the second modulation wave u _Ref2 , The third modulation wave u _Ref3 , the first load voltage U ₁ and the output voltage u _A1 of the first switch group, the second load voltage U ₂ and the voltage u _A2 of the second switch group, the third load voltage U ₃ and the third switch group voltage u _A3 , the DC input voltage U _dc and the fourth switch group voltage u _A4 . It can be seen from the waveform diagram that although U ₁ , U ₂ , and U ₃ are pulsating DC, their average values are respectively the target DC voltages of 200V, 160V, and 100V.

The above-mentioned embodiment is a preferred implementation mode of the present utility model, but the implementation mode of the present utility model is not limited by the described embodiment, and any other changes, modifications, modifications, Substitution, combination, and simplification should all be equivalent replacement methods, and are all included in the protection scope of the present utility model.

Claims (7)

1. Single-input multiple-output M-switch group DC-DC converter, characterized in that it includes a DC input power supply ( U _dc ), M-1 DC loads ( R ₁ , R ₂ ,..., R _M-1 ), M switch groups (A ₁ , A ₂ ,..., A _M ) and coupled inductors ( L _p : L _s ) are connected in series; the jth switch group (A _j ) consists of N power units (SM _Aj1 , SM _Aj2 ,..., SM _AjN ) in series, the value of j is 1~M, and N is a positive integer; the upper end of the jth switch group (A _j ) constitutes the jth port T _j of the converter, and the value of j is 1~M- 1. The lower end of the M-1th switch group constitutes the port TM, and the lower end of the _Mth switch group is connected to the ground point n. 2. The single-input multiple-output M switch group DC-DC converter according to claim 1, characterized in that: the voltage of the first port (T ₁ ) is U ₁ , and the voltage of the second port (T ₂ ) is U ₂ , sequentially, the voltage of the M-1th port ( _TM-1 ) is U _M-1 , the voltage of the Mth port ( _TM ) is U _M , and U ₁ > U ₂ >…> U _{M- 1} > U _M . 3. The single-input multiple-output M switch group DC-DC converter according to claim 1, characterized in that: DC input power supply ( U _dc ), M-1 DC loads ( R ₁ , R ₂ ,..., R _M-1 ) and M ports (T ₁ , T ₂ ,..., _TM ) have three different connection methods; the first method is: the first port (T ₁ ) is connected to the positive pole of the DC input power supply ( U _dc ), The negative pole of the DC input power supply ( U _dc ) is connected to the ground (n), and the second port (T ₂ ) to the Mth port (T _M ) are respectively connected to M-1 DC loads ( R ₁ , R ₂ , ..., R One end of _M-1 ) is connected, and the other end of M-1 DC load ( R ₁ , R ₂ ,…, R _M-1 ) is connected to the ground to realize the step-down function; the second method is: DC input power supply ( The positive pole of U _dc ) is connected to the M port, the negative pole of the DC input power supply ( U _dc ) is connected to the ground (n), and the first port (T ₁ ) to the M-1 port (T _M-1 ) are respectively connected to the M- One end of one DC load ( R ₁ , R ₂ ,…, RM - ₁ ) is connected, and the other end of M-1 DC loads ( R ₁ , R ₂ ,…, RM _-1 ) is connected to the ground to realize Boost function; the third method is: the positive pole of the DC input power supply ( U _dc ) is connected to the jth port, the value of j is 2~M-1, the negative pole of the DC input power supply ( U _dc ) is connected to the ground (n), The remaining M-1 ports are respectively connected to one end of M-1 DC loads ( R ₁ , R ₂ ,…, R _M-1 ), and M-1 DC loads ( R ₁ , R ₂ ,…, R _{M -1} ) The other end is connected to the ground, and at the same time realizes the buck-boost function. 4. The single-input multiple-output M switch group DC-DC converter according to claim 1, characterized in that: the coupling inductance can be equal to the two values of the upper bridge arm inductance ( L _p ) and the lower bridge arm inductance ( L _s ) stand-alone inductor replacement. 5. The single-input multiple-output M switch group DC-DC converter according to claim 1, characterized in that: the lower end of the first switch group (A ₁ ) is connected to the same-named end of the primary side of the coupling inductor ( L _p ), The non-identical end of the primary side of the coupled inductor ( L _p ) is connected to the upper end of the second switch group (A ₂ ), the lower end of the jth switch group (A _j ) is connected to the upper end of the j+1th switch group (A _j+1 ) connection, the value of j is 2~M-2, the lower end of the M-1 switch group is connected to the end with the same name of the secondary side of the coupled inductor ( L _s ), and the non-identical end of the secondary side of the coupled inductor ( L _s ) is connected to the end of the Mth The upper end of the switch group (A _M ) is connected, and the lower end of the Mth switch group (A _M ) is connected with the ground terminal (n). 6. The single-input multiple-output M-switch group DC-DC converter according to claim 1, characterized in that: the power switch unit includes a first switching tube (S ₁ ), a second switching tube (S ₂ ), a first Diode (D ₁ ), second diode (D ₂ ) and capacitor (C _SM ); wherein, the anode of the capacitor (C _SM ) is connected to the collector of the second switching tube (S ₂ ), and the second diode The cathode of the tube (D ₂ ), the emitter of the second switch tube (S ₂ ) and the anode of the second diode (D ₂ ), the collector of the first switch tube (S ₁ ), the first diode (D ₁ ) cathode connection, the emitter of the first switch tube (S ₁ ) is connected to the anode of the first diode (D ₁ ) and the cathode of the capacitor (C _SM ); the first switch tube (S ₁ ) The collector serves as the first output terminal, and the emitter of the first switching tube (S ₁ ) serves as the second output terminal. 7. The single-input multiple-output M switch group DC-DC converter according to claim 1, characterized in that: the second output terminal of the i-th power switch unit (SM _Aji ) of each switch group is connected to the i+ The first output terminal of one power switch unit (SM _Aj(i+1) ) is connected, wherein i takes a value of 1~(N-1), and j takes a value of 1~M.