A simple boost converter circuit and boost converter

Abstract

The application discloses a simple control boost conversion circuit and a boost converter. The boost conversion circuit comprises a power input end, a boost output end, a voltage conversion module, a first switch module, a boost module, a second switch module and a first unidirectional conduction module, one end of the voltage conversion module is connected with the power input end, and the other end of the voltage conversion module is connected with the boost output end; the first switch module is used for switching a switch state according to a first control signal; the boost module is used for realizing boost in cooperation with the voltage conversion module; one end of the second switch module is connected with the boost module, the other end of the second switch module is grounded, and the second switch module is used for switching a switch state according to a second control signal; one end of the first unidirectional conduction module is connected with the boost module, and the other end of the first unidirectional conduction module is connected with the power input end. The working state of the switch module is controlled to control the working of the circuit, the circuit structure is simplified, and the material cost of the product is reduced.

Description

Technical Field

[0001] This application relates to the field of voltage conversion technology, and in particular to a simple-to-control boost converter circuit and boost converter. Background Technology

[0002] In related technologies, the power device control circuit of existing interleaved boost converters is relatively complex, resulting in higher costs. Summary of the Invention

[0003] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a boost converter circuit that controls the operation of the circuit by controlling the working state of a control switching module, thereby simplifying the circuit structure and reducing the material cost of the product.

[0004] This application also proposes a boost converter having the above-described boost conversion circuit.

[0005] A boost converter circuit according to a first aspect embodiment of this application includes: a power input terminal for connecting to an input power supply; a boost output terminal for connecting to a power consumption circuit; a transformer module, one end of which is connected to the power input terminal and the other end of which is connected to the boost output terminal; a first switch module connected to the other end of the transformer module, which is used to switch a switch state according to a first control signal; a boost module connected to the first switch module, which is used to cooperate with the transformer module to achieve voltage boost; a second switch module, one end of which is connected to the boost module and the other end of which is grounded, which is used to switch a switch state according to a second control signal; and a first unidirectional conduction module, one end of which is connected to the boost module and the other end of which is connected to the power input terminal.

[0006] The boost converter circuit according to the embodiments of this application has at least the following beneficial effects: by controlling the working state of the control switch module to control the operation of the circuit, the circuit structure is simplified and the material cost of the product is reduced.

[0007] According to some embodiments of this application, the transformer module includes a first winding and a second winding. One end of the first winding is connected to the power input terminal, and the other end of the first winding is connected to the boost output terminal. One end of the second winding is connected to the power input terminal, and the other end of the second winding is connected to the boost output terminal.

[0008] According to some embodiments of this application, the first switching module includes a first field-effect transistor and a second field-effect transistor. The drain of the first field-effect transistor is connected to the other end of the first winding, and the source of the first field-effect transistor is connected to the boost module. The drain of the second field-effect transistor is connected to the other end of the second winding, and the source of the second field-effect transistor is connected to the boost module. The gates of both the first and second field-effect transistors are used to acquire the first control signal.

[0009] According to some embodiments of this application, the boost module includes a boost inductor, one end of which is connected to the source of the first field-effect transistor and the source of the second field-effect transistor, and the other end of which is connected to the second switching module and the first unidirectional conduction module.

[0010] According to some embodiments of this application, the second switching module includes a third field-effect transistor, the drain of which is connected to the other end of the boost inductor, the source of which is grounded, and the gate of which is used to acquire the second control signal.

[0011] According to some embodiments of this application, the first unidirectional conduction module includes a first diode, the anode of the first diode being connected to the other end of the boost inductor, and the cathode of the first diode being connected to the power input terminal.

[0012] According to some embodiments of this application, it further includes: a second unidirectional conduction module, one end of which is connected to the other end of the transformer module, and the other end of which is connected to the boost output terminal.

[0013] According to some embodiments of this application, the second unidirectional conduction module includes a second diode and a third diode. The anode of the second diode is connected to the other end of the first winding, and the cathode of the second diode is connected to the boost output terminal. The anode of the third diode is connected to the other end of the second winding, and the cathode of the third diode is connected to the boost output terminal.

[0014] According to some embodiments of this application, the first winding and the second winding are anti-coupled.

[0015] The boost converter according to a second aspect embodiment of this application includes the boost conversion circuit described in the first aspect embodiment.

[0016] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0017] The present application will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0018] Figure 1 This is a block diagram of one embodiment of the boost converter circuit of this application;

[0019] Figure 2 This is a block diagram of another embodiment of the boost converter circuit of this application;

[0020] Figure 3 This is a circuit diagram of one embodiment of the boost converter circuit of this application;

[0021] Figure 4 This is a simulation diagram of one embodiment of the boost converter circuit of this application.

[0022] Figure label:

[0023] Power input terminal 100, boost output terminal 200, transformer module 300, first switch module 400, boost module 500;

[0024] Second switch module 600, first unidirectional conduction module 700, and second unidirectional conduction module 800. Detailed Implementation

[0025] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0026] In the description of this application, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0027] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0028] The boost converter circuit of this application embodiment can be applied to interleaved boost converters. Interleaved boost converters perform excellently in terms of conversion efficiency, input power distribution, and reduced current ripple, and are therefore widely used. To improve the power density of interleaved boost converters, the multi-phase boost magnetic components can also be integrated into a single magnetic core.

[0029] In related technologies, the power device control circuit of existing interleaved boost converters is relatively complex, resulting in high cost and the problem of high stress on related power devices.

[0030] Based on this, this application proposes a simple boost converter circuit and boost converter, which controls the operation of the circuit by controlling the working state of the control switch module, thereby simplifying the circuit structure and reducing the material cost of the product.

[0031] Some embodiments, refer to Figure 1 The boost converter circuit includes: a power input terminal 100, a boost output terminal 200, a transformer module 300, a first switch module 400, a boost module 500, a second switch module 600, and a first unidirectional conduction module 700. The power input terminal 100 is used to connect to the input power supply; the boost output terminal 200 is used to connect to the power circuit; one end of the transformer module 300 is connected to the power input terminal 100, and the other end of the transformer module 300 is connected to the boost output terminal 200; the first switch module 400 is connected to the other end of the transformer module 300. The switch module 400 is used to switch the switch state according to the first control signal; the boost module 500 is connected to the first switch module 400 and is used to cooperate with the transformer module 300 to achieve voltage boost; one end of the second switch module 600 is connected to the boost module 500, and the other end of the second switch module 600 is grounded. The second switch module 600 is used to switch the switch state according to the second control signal; one end of the first unidirectional conduction module 700 is connected to the boost module 500, and the other end of the first unidirectional conduction module 700 is connected to the power input terminal 100.

[0032] In the embodiments of this application, the power input terminal 100 is used to connect to an external input power source. The boost output terminal 200 is the connection terminal for outputting the boosted voltage and is used to connect to the power circuit. The transformer module 300 typically includes a transformer. The duty cycle of the internal switching devices of the first switching module 400 is fixed and controlled by a first control signal. The first switching module 400 is used to switch the operation of different windings of the transformer inside the transformer module 300, but does not control the magnitude of the voltage at the boost output terminal 200. The second switching module 600 switches the switching state according to the second control signal, that is, it can control whether the boost module 500 is grounded. By controlling the on and off time of the second switching module 600, the magnitude of the boosted voltage is controlled. The first unidirectional conduction module 700 is used to prevent the power input terminal 100 from short-circuiting with the ground wire when the second switching module 600 is turned on.

[0033] The boost converter circuit of this application embodiment has at least the following beneficial effects: by controlling the working state of the control switch module to control the circuit operation, the circuit structure is simplified and the material cost of the product is reduced.

[0034] Some embodiments, refer to Figure 3 The transformer module 300 includes a first winding T1 and a second winding T2. One end of the first winding T1 is connected to the power input terminal 100, and the other end of the first winding T1 is connected to the boost output terminal 200. One end of the second winding T2 is connected to the power input terminal 100, and the other end of the second winding T2 is connected to the boost output terminal 200. The first winding T1 and the second winding T2 are transformer windings, and the coupling method between the two windings includes direct coupling and anti-coupling.

[0035] Some embodiments, refer to Figure 3 The first switching module 400 includes a first field-effect transistor (FET) Q1 and a second FET Q2. The drain of the first FET Q1 is connected to the other end of the first winding T1, and the source of the first FET Q1 is connected to the boost module 500. The drain of the second FET Q2 is connected to the other end of the second winding T2, and the source of the second FET Q2 is connected to the boost module 500. The gates of both the first FET Q1 and the second FET Q2 are used to acquire a first control signal. It should be noted that the gates of the first FET Q1 and the second FET Q2 are respectively connected to two control pins of an external control chip. The first control signal is a set of level signals sent by the external control chip, which can control the high and low levels of the gates of the first FET Q1 and the second FET Q2, thereby controlling the first FET Q1 and the second FET Q2 to operate in the on or off state, respectively. At any given time, only one of the first FET Q1 and the second FET Q2 is in the on state, and the other is in the off state. Furthermore, the on-time and off-time of each field-effect transistor are the same, that is, the duty cycle of the first field-effect transistor Q1 and the second field-effect transistor Q2 are both 50%. In one embodiment, the first field-effect transistor Q1 and the second field-effect transistor Q2 can also be replaced with switches to achieve on-off control, but this will increase the control complexity.

[0036] Some embodiments, refer to Figure 3 The boost module 500 includes a boost inductor L1. One end of the boost inductor L1 is connected to the source of the first field-effect transistor Q1 and the source of the second field-effect transistor Q2, respectively. The other end of the boost inductor L1 is connected to the second switching module 600 and the first unidirectional conduction module 700, respectively. When the second switching module 600 is off, the boost inductor L1 is connected to the transformer module 300 through the first unidirectional conduction module 700, and the boost inductor L1 operates in the on state. When the second switching module 600 is on, the boost inductor L1 is grounded through the second switching module 600, and the boost inductor L1 operates in the off state. By controlling the on-time and off-time of the boost inductor L1, the output voltage of the boost conversion circuit can be controlled.

[0037] Some embodiments, refer to Figure 3The second switching module 600 includes a third field-effect transistor (FET) Q3. The drain of FET Q3 is connected to the other end of the boost inductor L1, the source of FET Q3 is grounded, and the gate of FET Q3 is used to acquire a second control signal. It should be noted that the gate of FET Q3 is also used to connect to the control pin of an external control chip. The second control signal is a level signal sent by the external control chip, which can control FET Q3 to operate in the on or off state, thereby controlling the boost inductor L1 to operate in the on or off state. By controlling the on and off times of FET Q3, the on and off times of boost inductor L1 can be controlled, thus controlling the output voltage of the boost converter circuit.

[0038] Some embodiments, refer to Figure 3 The first unidirectional conduction module 700 includes a first diode D1, the anode of which is connected to the other end of the boost inductor L1, and the cathode of which is connected to the power input terminal 100. The first diode D1 is used to prevent the power input terminal 100 from being short-circuited to ground when the third field-effect transistor Q3 is in the on state.

[0039] Some embodiments, refer to Figure 2 The boost converter circuit also includes: a second unidirectional conduction module 800, one end of which is connected to the other end of the transformer module 300, and the other end of which is connected to the boost output terminal 200.

[0040] Some embodiments, refer to Figure 3 The second unidirectional conduction module 800 includes a second diode D2 and a third diode D3. The anode of the second diode D2 is connected to the other end of the first winding T1, and the cathode of the second diode D2 is connected to the boost output terminal 200. The anode of the third diode D3 is connected to the other end of the second winding T2, and the cathode of the third diode D3 is connected to the boost output terminal 200. The second diode D2 and the third diode D3 are used to prevent voltage reverse flow in the electrical circuit.

[0041] In some embodiments, the first winding T1 and the second winding T2 are anti-coupled.

[0042] Some embodiments, refer to Figure 3 The boost converter circuit also includes a fourth diode D4. The cathode of the fourth diode D4 is connected to the source of the first field-effect transistor Q1 and the source of the second field-effect transistor Q2, respectively, and the anode of the fourth diode D4 is grounded. The fourth diode D4 is used to control the current flow to the boost inductor L1.

[0043] In illustrative embodiments, in the boost converter circuit of this application, refer to... Figure 3The output voltage of the boost converter circuit is controlled by controlling the on / off state of the third field-effect transistor Q3. Let point A be the connection point between the boost inductor L1 and the source of the first field-effect transistor Q1 and the source of the second field-effect transistor Q2, and let the voltage at this point be V. A A 100V power input charges the first winding T1 and the second winding T2 of the transformer.

[0044] With the third MOSFET Q3 conducting, the current enters through the power input terminal 100. As it flows through the first winding T1 and the second winding T2, it splits into two paths: one flows to the power consumption circuit, and the other flows to ground via the first or second transistor, the boost inductor L1, and the third MOSFET Q3. The current in the boost inductor L1 increases, and its current change is:

[0045]

[0046] In equation (1), Δi L This represents the change in current of boost inductor L1 when the third field-effect transistor Q3 is turned on, where L represents the inductance of boost inductor L1, and V represents the current change of boost inductor L1. A Represents the voltage at point A, t on This indicates the on-time of the boost inductor L1 (i.e., the on-time of the third field-effect transistor Q3).

[0047] If the first transistor is on, the second transistor is off, the second diode D2 is off, and the third diode D3 is on, the current flowing through the first winding T1 and the second winding T2 is the same, but the voltages are opposite. Assume the voltage at the power input terminal 100 is V. in The voltage at the boost output terminal is 200V. out The terminal voltage of the first winding T1 is V. T1 The terminal voltage of the second winding T2 is V. T2 Then we have:

[0048] V A =V in -V T1 (2)

[0049] V T1 =-V T2 (3)

[0050] V T2 =V out -V in (4)

[0051] According to equations (2), (3), and (4), we can obtain:

[0052] V A =2V in -V out (5)

[0053] If the first transistor is off, the second transistor is on, the second diode D2 is on, and the third diode D3 is off, then:

[0054] V A =V in -V T2 (6)

[0055] V T1 =V out -V in (7)

[0056] Equation (5) can also be obtained from equations (3), (6), and (7). Ignoring the on-state voltage drop of the field-effect transistor, the voltage at point A is the electromotive force voltage of the boost inductor L1. Therefore, combining equations (1) and (7), the change in current of the boost inductor L1 when the third field-effect transistor Q3 is turned on is:

[0057]

[0058] In equation (8), Δi L This represents the change in current of boost inductor L1 when the third field-effect transistor Q3 is turned on, where L represents the inductance of boost inductor L1, and V represents the current change of boost inductor L1. in Indicates a power input voltage of 100V. out This indicates a boost output voltage of 200V, t on This indicates the on-time of the boost inductor L1 (i.e., the on-time of the third field-effect transistor Q3).

[0059] When the third field-effect transistor Q3 is off, the energy stored in the boost inductor L1 freewheels through the second diode D2 or the third diode D3, and the current in the boost inductor L1 decreases. The change in current is:

[0060]

[0061] In equation (9), ΔI L This represents the change in current of boost inductor L1 when the third MOSFET Q3 is off, where L represents the inductance of boost inductor L1, and V represents the current change of boost inductor L1. A Represents the voltage at point A, t off This indicates the turn-off time of the boost inductor L1 (i.e., the cut-off time of the third field-effect transistor Q3).

[0062] Assume the voltage at the power input terminal is 100V. in The voltage at the boost output terminal is 200V. out The terminal voltage of the first winding T1 is V. T1 The terminal voltage of the second winding T2 is V. T2 Then we have:

[0063] V A =-V T1 (10)

[0064] V T1 =-V T2 (11)

[0065] V T2 =V out -V in (12)

[0066] According to equations (9), (10), (11), and (12), we can obtain:

[0067]

[0068] Since the boost inductor L1 operates in continuous mode, its current changes the same during the conduction or cutoff of the third field-effect transistor Q3. According to equations (8) and (13), we can obtain:

[0069]

[0070] Simplifying expression (14), we get:

[0071]

[0072] In equation (15), That is, the duty cycle of the third field-effect transistor Q3, denoted by D, and equation (15) is transformed into:

[0073] V out = (1+D)×V in (16)

[0074] As can be seen from equation (16), the output voltage of the boost converter circuit depends on the magnitude of the input voltage and the duty cycle of the third field-effect transistor Q3. Therefore, with the external power supply unchanged, the final output voltage can be controlled simply by controlling the on-time and off-time of the third field-effect transistor Q3. This simplifies the circuit structure and reduces the material cost of the product.

[0075] Furthermore, in the embodiments of this application, the voltage stress on the field-effect transistor and the diode is relatively small.

[0076] Reference Figure 3 and Figure 4 , Figure 4 This is a simulation diagram of the boost converter circuit according to an embodiment of this application. The electrical load is a purely resistive load of 25 ohms, and the voltage at the power input terminal 100 is 75V. In the diagram, VOUT is the output voltage, and VA is... Figure 3The voltage at point A is given, I-T1 is the current in the first winding T1, I-T2 is the current in the second winding T2, and I-L3 is the current in the boost inductor L1.

[0077] In some embodiments, the boost converter includes the boost conversion circuit of any of the above embodiments.

[0078] In the description of this application, references to terms such as "one embodiment," "some embodiments," or "illustrative embodiment," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0079] The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this application. Furthermore, unless otherwise specified, the embodiments and features described in the embodiments of this application can be combined with each other.

Claims

1. A boost converter circuit, characterized in that, include: A power input terminal, which is used to connect an input power source; A boost output terminal is used to connect to an electrical circuit. A transformer module, one end of which is connected to the power input terminal and the other end of which is connected to the boost output terminal; the transformer module includes a first winding and a second winding, one end of which is connected to the power input terminal and the other end of which is connected to the boost output terminal, and one end of which is connected to the power input terminal and the other end of which is connected to the boost output terminal. A first switching module is connected to the other end of the transformer module. The first switching module is used to switch the switching state according to a first control signal. The first switching module includes a first field-effect transistor (FET) and a second field-effect transistor (FET). The drain of the first FET is connected to the other end of the first winding, and the source of the first FET is connected to the boost module. The drain of the second FET is connected to the other end of the second winding, and the source of the second FET is connected to the boost module. The gates of both the first and second FETs are used to acquire the first control signal. A boost module is connected to the first switching module and is used to cooperate with the transformer module to achieve voltage boosting. The boost module includes a boost inductor, one end of which is connected to the source of the first field-effect transistor and the source of the second field-effect transistor, and the other end of which is connected to the second switching module and the first unidirectional conduction module. The second switching module has one end connected to the boost module and the other end grounded. The second switching module is used to switch the switching state according to the second control signal. A first unidirectional conduction module, one end of which is connected to the boost module, and the other end of which is connected to the power input terminal.

2. The boost converter circuit according to claim 1, characterized in that, The second switching module includes a third field-effect transistor, the drain of which is connected to the other end of the boost inductor, the source of which is grounded, and the gate of which is used to acquire the second control signal.

3. The boost converter circuit according to claim 2, characterized in that, The first unidirectional conduction module includes a first diode, the anode of which is connected to the other end of the boost inductor, and the cathode of which is connected to the power input terminal.

4. The boost converter circuit according to claim 1, characterized in that, Also includes: The second unidirectional conduction module has one end connected to the other end of the transformer module and the other end connected to the boost output terminal.

5. The boost converter circuit according to claim 4, characterized in that, The second unidirectional conduction module includes a second diode and a third diode. The anode of the second diode is connected to the other end of the first winding, and the cathode of the second diode is connected to the boost output terminal. The anode of the third diode is connected to the other end of the second winding, and the cathode of the third diode is connected to the boost output terminal.

6. The boost converter circuit according to claim 1, characterized in that, The first winding and the second winding are anti-coupled.

7. A boost converter, characterized in that, Includes the boost converter circuit as described in any one of claims 1 to 6.

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