A boost circuit

Abstract

The present application provides a boost circuit, which includes a Z-source circuit, a voltage sampling circuit, a first control unit, a second control unit, a controller, and a comparator. The voltage sampling circuit is used to collect the voltage of the first input source and the voltage of the first output source. The comparator compares the first divided voltage value and the second divided voltage value, and controls the conduction or cut-off of the second control unit according to the comparison result. At the same time, the controller controls the conduction or cut-off of the first control unit according to the relationship between the triangular carrier wave and the modulation wave. Then, the first control unit and the second control unit jointly control the Z-source circuit to be in a direct-conduction state or a non-direct-conduction state. When the Z-source circuit is in the direct-conduction state, a boost operation is performed to make the voltage of the first output source greater than the voltage of the first input source. When the Z-source circuit is in the non-direct-conduction state, the boost operation cannot be performed, and the voltage of the first output source slowly drops until it is within the protection voltage range, thereby realizing overvoltage protection for the Z-source circuit.

Description

Technical Field

[0001] This application relates to the field of power electronics, and particularly to a boost circuit. Background Art

[0002] With the wide application of renewable energy, power electronic converters have also developed rapidly. For example, the Z-source converter has boost-buck capabilities. It can control the DC bus voltage by adjusting the shoot-through duty cycle and enables the upper and lower bridge arms of the inverter to shoot through by adding a shoot-through vector, which can improve the reliability of the system. Therefore, it has great application prospects in fields such as distributed generation, wind power generation, fuel cell power supply, and motor drive.

[0003] During the boost process of the Z-source circuit in the Z-source converter, if the boost is too high, it may cause damage to the Z-source converter. Therefore, overvoltage protection for the Z-source circuit is particularly important. Summary of the Invention

[0004] This application provides a boost circuit for overvoltage protection of the Z-source circuit.

[0005] In a first aspect, this application provides a boost circuit, including:

[0006] A Z-source circuit, which is connected to a first input source and a first output source and is used to boost the voltage of the first input source;

[0007] A voltage sampling circuit, which is connected to the first input source and the first output source and is used to collect the voltage of the first input source and the voltage of the first output source;

[0008] A first control unit and a second control unit, which are jointly used to control the Z-source circuit to be in a shoot-through state or a non-shoot-through state;

[0009] A controller, which is connected to the first control unit and is used to control the conduction or cutoff of the first control unit;

[0010] A comparator, which is connected to the voltage sampling circuit and the second control unit and is used to compare a first divided voltage value and a second divided voltage value, and control the conduction or cutoff of the second control unit according to the comparison result. The first divided voltage value is obtained based on the voltage of the first input source, and the second divided voltage value is obtained based on the voltage of the first output source.

[0011] Optionally, the Z-source circuit includes:

[0012] A first inductor, whose first end is connected to the positive pole of the first input source;

[0013] A first diode, whose positive pole is connected to the second end of the first inductor;

[0014] A second inductor, whose first end is connected to the negative electrode of the first diode;

[0015] A second diode, whose positive electrode is connected to the second end of the second inductor and whose negative electrode is connected to the positive electrode of the first output source;

[0016] A first capacitor, whose positive electrode is connected to the negative electrode of the first diode and the first end of the second inductor, and whose negative electrode is connected to the negative electrode of the first input source;

[0017] A second capacitor, whose negative electrode is connected to the second end of the first inductor and the positive electrode of the first diode, and whose positive electrode is connected to the second end of the second inductor and the positive electrode of the second diode;

[0018] A third capacitor, whose positive electrode is connected to the negative electrode of the second diode and the positive electrode of the first output source, and whose negative electrode is connected to the negative electrode of the first capacitor and the negative electrode of the first output source.

[0019] Optionally, the voltage sampling circuit includes: a first voltage dividing circuit and a second voltage dividing circuit;

[0020] The first voltage dividing circuit includes:

[0021] A first resistor, whose first end is connected to the positive electrode of the first input source and the first end of the first inductor;

[0022] A second resistor, whose first end is connected to the second end of the first resistor and whose second end is connected to the negative end of the first input source, the negative electrode of the first capacitor, the negative electrode of the third capacitor, and the negative electrode of the first output source;

[0023] The second voltage dividing circuit includes:

[0024] A third resistor, whose first end is connected to the negative electrode of the second diode, the positive electrode of the third capacitor, and the positive electrode of the first output source;

[0025] A fourth resistor, whose first end is connected to the second end of the third resistor and whose second end is connected to the negative electrode of the first input source, the negative electrode of the third capacitor, the negative electrode of the first capacitor, and the negative electrode of the first output source.

[0026] Optionally, the non-inverting input terminal of the comparator is connected to the second end of the first resistor and the first end of the second resistor, and the inverting input terminal is connected to the second end of the third resistor and the first end of the fourth resistor.

[0027] Optionally, the first control unit includes a first control transistor, whose drain is connected to the second end of the second inductor and the positive electrode of the second diode, and whose gate is connected to the output terminal of the comparator.

[0028] Optionally, the second control unit includes a second control transistor, whose drain is connected to the source of the first control transistor, whose source is connected to the first capacitor and the negative electrode of the third capacitor, and whose gate is connected to the controller.

[0029] Optionally, the controller is configured to control the first control unit to turn on when the triangular carrier wave is less than the modulation wave;

[0030] The comparator is configured to control the second control unit to turn on when the first divided voltage value is greater than the second divided voltage value;

[0031] Correspondingly, the first control unit and the second control unit are configured to control the Z-source circuit to be in a direct connection state.

[0032] Optionally, the controller is configured to control the first control unit to turn off when the triangular carrier wave is greater than the modulation wave;

[0033] The comparator is configured to control the second control unit to turn on when the first divided voltage value is greater than the second divided voltage value;

[0034] Correspondingly, the first control unit and the second control unit are configured to control the Z-source circuit to be in a non-direct connection state.

[0035] Optionally, the controller is configured to control the first control unit to turn on when the triangular carrier wave is less than the modulation wave;

[0036] The comparator is configured to control the second control unit to turn off when the first divided voltage value is less than the second divided voltage value;

[0037] Correspondingly, the first control unit and the second control unit are configured to control the Z-source circuit to be in a direct connection state.

[0038] Optionally, the controller is configured to control the first control unit to turn off when the triangular carrier wave is greater than the modulation wave;

[0039] The comparator is configured to control the second control unit to turn off when the first divided voltage value is less than the second divided voltage value;

[0040] Correspondingly, the first control unit and the second control unit are configured to control the Z-source circuit to be in a direct connection state.

[0041] The boost circuit provided by this application includes a Z-source circuit, a voltage sampling circuit, a first control unit, a second control unit, a controller, and a comparator. The Z-source circuit is connected to a first input source and a first output source, and is used to boost the voltage of the first input source. The voltage sampling circuit is connected to the first input source and the first output source, and is used to collect the voltage of the first input source and the voltage of the first output source. The first control unit and the second control unit are jointly used to control the Z-source circuit to be in a direct-conduction state or a non-direct-conduction state. The controller is connected to the first control unit and is used to control the conduction or cut-off of the first control unit. The comparator is connected to the voltage sampling circuit and the second control unit, and is used to compare a first voltage-dividing value and a second voltage-dividing value, and control the conduction or cut-off of the second control unit according to the comparison result. In this way, the voltage sampling circuit collects the voltage of the first input source and the voltage of the first output source, the comparator compares the first voltage-dividing value obtained from the voltage of the first input source and the second voltage-dividing value obtained from the voltage of the first output source, and controls the conduction or cut-off of the second control unit according to the comparison result. At the same time, the controller controls the conduction or cut-off of the first control unit according to the relationship between the triangular carrier wave and the modulation wave. Then, the first control unit and the second control unit jointly control the Z-source circuit to be in a direct-conduction state or a non-direct-conduction state. When the Z-source circuit is in the direct-conduction state, a boost operation is performed so that the voltage of the first output source is greater than the voltage of the first input source. When the Z-source circuit is in the non-direct-conduction state, the boost operation cannot be performed, and the voltage of the first output source slowly drops until it is within the protection voltage range, thereby realizing overvoltage protection for the Z-source circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in this application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of this application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0043] Figure 1 It is a circuit structure diagram of a boost circuit provided by an embodiment of this application;

[0044] Figure 2 It is a circuit structure diagram of a boost circuit provided by an embodiment of this application;

[0045] Figure 3 It is a circuit structure diagram of a boost circuit provided by an embodiment of this application;

[0046] Figure 4 It is a circuit structure diagram of a boost circuit provided by an embodiment of this application;

[0047] Figure 5 It is a circuit structure diagram of a boost circuit provided by an embodiment of this application. Detailed implementation manners

[0048] To make the objectives, technical solutions and advantages of this application clearer, the technical solutions in this application will be clearly and completely described below with reference to the accompanying drawings in this application. Apparently, the described embodiments are some, but not all, of the embodiments of this application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in this application without creative efforts shall fall within the scope of protection of this application.

[0049] As described in the background art, the Z-source circuit may be damaged due to excessive voltage boost during the voltage boost process. Therefore, overvoltage protection for the Z-source circuit is required.

[0050] To address the above problems, this application proposes a boost circuit, which includes a Z-source circuit, a voltage sampling circuit, a first control unit, a second control unit, a controller, and a comparator. The Z-source circuit is connected to a first input source and a first output source and is used to boost the voltage of the first input source. The voltage sampling circuit is connected to the first input source and the first output source and is used to collect the voltage of the first input source and the voltage of the first output source. The first control unit and the second control unit are jointly used to control the Z-source circuit to be in a direct-conduction state or a non-direct-conduction state. The controller is connected to the first control unit and is used to control the conduction or cutoff of the first control unit. The comparator is connected to the voltage sampling circuit and the second control unit and is used to compare a first divided voltage value obtained from the voltage of the first input source and a second divided voltage value obtained from the voltage of the first output source, and control the conduction or cutoff of the second control unit according to the comparison result. In this way, the voltage sampling circuit collects the voltage of the first input source and the voltage of the first output source, the comparator compares the first divided voltage value and the second divided voltage value, and controls the conduction or cutoff of the second control unit according to the comparison result. At the same time, the controller controls the conduction or cutoff of the first control unit according to the relationship between the triangular carrier wave and the modulation wave. Then, the first control unit and the second control unit jointly control the Z-source circuit to be in a direct-conduction state or a non-direct-conduction state. When the Z-source circuit is in the direct-conduction state, a boost operation is performed so that the voltage of the first output source is greater than the voltage of the first input source. When the Z-source circuit is in the non-direct-conduction state, the boost operation cannot be performed, and the voltage of the first output source slowly decreases until it is within the protection voltage range, thereby realizing overvoltage protection for the Z-source circuit. And by controlling the conduction or cutoff of the first control unit and the conduction or cutoff of the second control unit to control the Z-source circuit to be in a direct-conduction state or a non-direct-conduction state, the loss can be reduced, the power factor of the DC-DC can be improved, and the charging efficiency of the integrated charging can be further improved.

[0051] The technical solutions of this application will be described in detail below with specific embodiments. These specific embodiments below can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments.

[0052] Figure 1 The circuit structure diagram of a boost circuit provided by an embodiment of the present application is shown. The boost circuit of this embodiment includes:

[0053] A Z-source circuit 101, which is connected to a first input source U in1 and a first output source U out1 , and is used to boost the voltage of the first input source U in1 ;

[0054] Voltage sampling circuits 102, 107, which are connected to the first input source U in1 and the first output source U out1 , and are used to collect the voltage of the first input source U in1 and the voltage of the first output source U out1 ;

[0055] A first control unit 103 and a second control unit 104, which are jointly used to control the Z-source circuit to be in a direct conduction state or a non-direct conduction state;

[0056] A controller 106, which is connected to the first control unit 103 and is used to control the conduction or cut-off of the first control unit 103;

[0057] A comparator 105, which is connected to the voltage sampling circuits 102, 107 and the second control unit 104, and is used to compare a first divided voltage value and a second divided voltage value, and control the conduction or cut-off of the second control unit 104 according to the comparison result. The first divided voltage value is obtained according to the voltage of the first input source U in1 , and the second divided voltage value is obtained according to the voltage of the first output source U out1 .

[0058] The voltage sampling circuits 102, 107 collect the voltage of the first input source U in1 and the voltage of the first output source U out1 . The comparator 105 compares the first divided voltage value obtained from the voltage of the first input source U in1 with the second divided voltage value obtained from the voltage of the first output source U out1 . When the first divided voltage value is greater than the second divided voltage value, the output terminal of the comparator 105 outputs a first driving signal g s1 , and the first driving signal g s1 controls the second control unit 104 to conduct. When the first divided voltage value is less than the second divided voltage value, the output terminal of the comparator 105 outputs a second driving signal g s2 , and the second driving signal g s2 controls the second control unit 104 to cut off.

[0059] The controller 106 controls the conduction or cut-off of the first control unit 103 by using Pulse Width Modulation (PWM). When the triangular carrier wave is less than the modulation wave D, the controller 106 controls the first control unit 103 to conduct. When the triangular carrier wave is greater than the modulation wave D, the controller 106 controls the first control unit 103 to cut off.

[0060] The first control unit 103 is connected to the Z-source circuit 101, and the second control unit 104 is connected to the first control unit 103. The first control unit 103 and the second control unit 104 jointly control the Z-source circuit 101 to be in a direct-through state or a non-direct-through state. When the first control unit 103 conducts and the second control unit 104 conducts, the Z-source circuit 101 is in a direct-through state. When the first control unit 103 cuts off and the second control unit 104 conducts, the Z-source circuit 101 is in a non-direct-through state. When the first control unit 103 conducts and the second control unit 104 cuts off, the Z-source circuit 101 is in a non-direct-through state. When the first control unit 103 cuts off and the second control unit 104 cuts off, the Z-source circuit 101 is in a non-direct-through state.

[0061] The comparator 105 is connected to the voltage sampling circuits 102, 107 and the second control unit 104, and obtains the voltage of the first input source U in1 and the voltage of the first output source U out1 through the voltage sampling circuits 102, 107. It compares the first voltage division value obtained from the voltage of the first input source U in1 with the second voltage division value obtained from the voltage of the first output source U out1 and issues a first drive signal g S1 according to the comparison result. When the comparison result indicates that the first voltage division value is greater than the second voltage division value, it controls the second control unit 104 to conduct. When the comparison result indicates that the first voltage division value is less than the second voltage division value, it controls the second control unit 104 to cut off.

[0062] In some embodiments, as shown in Figure 1 , the Z-source circuit includes a first inductor L1, a first diode D1, a second inductor L2, a second diode D2, a first capacitor C1, a second capacitor C2 and a third capacitor C3. The first end of the first inductor L1 is connected to the positive pole of the first input source U in1 . The positive pole of the first diode D1 is connected to the second end of the first inductor L1. The first end of the second inductor L2 is connected to the negative pole of the first diode D1. The positive pole of the second diode D2 is connected to the second end of the second inductor L2. The negative pole of the second diode D2 is connected to the negative pole of the first output source U out1 . The positive pole of the first capacitor C1 is connected to the negative pole of the first diode D1 and the first end of the second inductor L2. The negative pole of the first capacitor C1 is connected to the first input source U in1The negative electrode of the first capacitor C1, the negative electrode of the second capacitor C2 is connected to the second end of the first inductor L1 and the positive electrode of the first diode D1, the positive electrode of the second capacitor C2 is connected to the second end of the second inductor L2 and the positive electrode of the second diode D2, the positive electrode of the third capacitor C3 is connected to the negative electrode of the second diode D2 and the first output source U out1 The positive electrode, the negative electrode of the third capacitor C3 is connected to the negative electrode of the first capacitor C1 and the negative electrode of the first output source U out1 Negative electrode.

[0063] In some embodiments, the voltage sampling circuits 102 and 107 include a first voltage dividing circuit 102 and a second voltage dividing circuit 107. The first voltage dividing circuit 102 includes a first resistor R1 and a second resistor R2. The first end of the first resistor R1 is connected to the positive electrode of the first input source U in1 And the first end of the first inductor L1, the first end of the second resistor R2 is connected to the second end of the first resistor R1, and the second end of the second resistor R2 is connected to the negative electrode of the first input source U in1 Negative terminal and the first output terminal U out1 Negative end, the second voltage dividing circuit 107 includes a third resistor R3 and a fourth resistor R4. The first end of the third resistor R3 is connected to the negative electrode of the second diode D2, the third capacitor C3 and the first output terminal U out1 Positive electrode, the first end of the fourth resistor R4 is connected to the second end of the third resistor R3, and the second end of the fourth resistor R4 is connected to the negative electrode of the first output source U out1 Negative electrode, the negative electrode of the third capacitor C3, the negative electrode of the first capacitor C1 and the negative electrode of the first input source U in1 Negative electrode.

[0064] The first voltage division value can be the voltage division of the first resistor R1 in the first input source U in1 The second voltage division value can be the voltage division of the fourth resistor R4 in the first output source U out1 When the first voltage division value is greater than the second voltage division value, that is, when U in1 R2 / (R1 + R2) > U out1 R4 / (R3 + R4), the comparator 105 controls the second control unit 104 to conduct. When the triangular carrier wave is less than the modulation wave D, the controller 106 controls the first control unit 103 to conduct. When the first control unit 103 conducts and the second control unit 104 conducts, the Z-source circuit 101 is in a direct-through state. At this time, the working mode of the Z-source circuit 101 is as Figure 2 Shown, the first diode D1 and the second diode D2 are turned off, the first inductor L1, the second inductor L2 and the second capacitor C2 store energy, and the first capacitor C1 and the third capacitor C3 release energy.

[0065] The circuit equation in the direct-through state is:

[0066]

[0067] When the first partial pressure value is greater than the second partial pressure value, i.e., U in1 R2 / (R1 + R2) > U out1 R4 / (R3 + R4), comparator 105 controls the conduction of the second control unit 104. When the triangular carrier wave is greater than the modulation wave D, controller 106 controls the first control unit 103 to turn off. When the first control unit 103 is conducting and the second control unit 104 is off, the Z-source circuit 101 is in a non-through state. At this time, the working mode of the Z-source circuit 101 is as Figure 3 shown. The first inductor L1, the second inductor L1, and the second capacitor C2 release energy, and the first capacitor C1 and the third capacitor C3 store energy.

[0068] The circuit equation in the non-through state is:

[0069]

[0070] Since the Z-source is symmetrically distributed, so U C2 = U C1； According to the volt-second theorem, the integral of the voltage across the inductor within a switching period T is 0. Assuming the through duty cycle is D, then from formula (1) and formula (2), we can get:

[0071]

[0072] That is: D0(U C3 + U C1 ) = D0(3U C1 - U in1 ) = D0(3U C2 - U in1 ) = (D0 - 1)(U in1 - U C2 ) (4)

[0073] (1 - 4D0)U C2 = (1 - 2D0)(U in1 ) (5)

[0074] Simplifying formula (4) and formula (5) gives:

[0075] U C1 = U C2 = (1 - 2D) / (1 - 4D)U in1 (6)

[0076] U C3 = 1 / (1 - 4D)U in1 (7)

[0077] Then, according to formula (1), formula (2), and formula (7), we know:

[0078] U out1 = U C3 = 1 / (1 - 4D)U in1 (8)

[0079] In this way, when U in1 R2 / (R1 + R2) > U out1 R4 / (R3 + R4), comparator 105 controls the second control unit 104 to turn on. When the triangular carrier wave is less than the modulation wave D, controller 106 controls the first control unit 103 to turn on. The first control unit 103 and the second control unit 104 control the Z-source circuit 101 to be in a direct-through state. Then, when the triangular carrier wave is greater than the modulation wave D, controller 106 controls the first control unit 103 to turn off. The first control unit 103 and the second control unit 104 control the Z-source circuit 101 to be in a non-direct-through state, so that the Z-source circuit operates in a boost mode.

[0080] When the first voltage division value is less than the second voltage division value, that is, when U in1 R2 / (R1 + R2) < U out1 R4 / (R3 + R4), comparator 105 controls the second control unit 104 to turn off. When the triangular carrier wave is less than the modulation wave D, controller 106 controls the first control unit 103 to turn on. The first control unit 103 is turned on and the second control unit 104 is turned off, and the Z-source circuit 101 is in a non-direct-through state. At this time, the working mode of the Z-source circuit 101 is as Figure 4 shown. The first inductor L1, the second inductor L2, and the second capacitor C2 release energy, and the first capacitor C1 and the third capacitor C3 store energy. The voltage of the first input source U in1 is equal to the voltage of the first output source U out1 . When the first voltage division value is greater than the second voltage division value, that is, when U in1 R2 / (R1 + R2) < U out1 R4 / (R3 + R4), comparator 105 controls the second control unit 104 to turn off. When the triangular carrier wave is greater than the modulation wave D, controller 106 controls the first control unit 103 to turn off. The first control unit 103 is turned off and the second control unit 104 is turned off, and the Z-source circuit 101 is in a non-direct-through state. At this time, the working mode of the Z-source circuit 101 is as Figure 5 shown. The first inductor L1, the second inductor L2, and the second capacitor C2 release energy, and the first capacitor C1 and the third capacitor C3 store energy. The voltage of the first input source U in1 is equal to the voltage of the first output source U out1 .

[0081] In this way, when U in1 R2 / (R1 + R2) < U out1When R4 / (R3 + R4), the comparator 105 controls the second control unit 104 to turn off. When the triangular carrier is less than the modulation wave D, the controller 106 controls the first control unit 103 to turn on, and the first control unit 103 and the second control unit 104 control the Z-source circuit 101 to be in a non-through state. Then, when the triangular carrier is greater than the modulation wave D, the controller 106 controls the first control unit 103 to turn off, and the first control unit 103 and the second control unit 104 control the Z-source circuit 101 to be in a non-through state. Then U in1 R2 / (R1 + R2) < U out1 When R4 / (R3 + R4), the second control unit 104 turns off, causing the voltage of the first output source U out1 to drop, thereby completing overvoltage protection.

[0082] The non-inverting input terminal of the comparator 105 is connected to the second end of the first resistor R1 and the first end of the second resistor R2, and the inverting input terminal is connected to the second end of the third resistor R3 and the first end of the fourth resistor R4. Therefore, the comparator 105 can compare the voltage of the second resistor R2 with the voltage of the fourth resistor R4, that is, compare U in1 R2 / (R1 + R2) and U out1 R4 / (R3 + R4). When the second resistor R2 is greater than the fourth resistor R4, that is, U in1 R2 / (R1 + R2) > U out1 R4 / (R3 + R4), the comparator 105 controls the second control unit 104 to turn on. When the second resistor R2 is less than the fourth resistor R4, that is, U in1 R2 / (R1 + R2) < U out1 R4 / (R3 + R4), the comparator 105 controls the second control unit 104 to turn off. In this way, hardware voltage protection is achieved through resistors and comparators, saving device costs and resources.

[0083] In some embodiments, the first control unit 103 includes a first control transistor S1. The drain of the first control transistor S1 is connected to the second end of the second inductor L2 and the positive electrode of the second diode D2. The gate of the first control transistor S1 is connected to the output terminal of the comparator 105, and the first control transistor S1 is turned on or off under the control of the comparator 105. The second control unit 104 includes a second control transistor S2. The drain of the second control transistor S2 is connected to the source of the first control transistor S1. The source of the second control transistor S2 is connected to the negative electrodes of the first capacitor C1 and the third capacitor C3. The gate of the second control transistor S2 is connected to the controller 106, and the second control transistor S2 is turned on or off under the control of the controller 106.

[0084] The boost circuit provided by the present application has been described in detail above. The voltage sampling circuit is used to collect the voltage of the first input source and the voltage of the first output source. The comparator compares the first divided voltage value and the second divided voltage value, and controls the conduction or cutoff of the second control unit according to the comparison result. At the same time, the controller controls the conduction or cutoff of the first control unit according to the relationship between the triangular carrier wave and the modulation wave. Then, the first control unit and the second control unit jointly control the Z-source circuit to be in a direct connection state or a non-direct connection state. When the Z-source circuit is in the direct connection state, a boost operation is performed so that the voltage of the first output source is greater than the voltage of the first input source. When the Z-source circuit is in the non-direct connection state, the boost operation cannot be performed, and the voltage of the first output source slowly decreases until it is within the protection voltage range, thereby realizing overvoltage protection for the Z-source circuit.

[0085] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit them. Although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A boost circuit, characterized in that, Comprising: A Z-source circuit, connected to a first input source and a first output source, for boosting the voltage of the first input source; A voltage sampling circuit, connected to the first input source and the first output source, for collecting the voltage of the first input source and the voltage of the first output source; A first control unit and a second control unit, jointly used to control the Z-source circuit to be in a direct-conduction state or a non-direct-conduction state; when both the first control unit and the second control unit are in a conducting state, controlling the Z-source circuit to be in a direct-conduction state for boosting the voltage of the first input source; when the conducting states of the first control unit and the second control unit are different or both the first control unit and the second control unit are in an off state, controlling the Z-source circuit to be in a non-direct-conduction state so that the voltage of the first output source drops; A controller, connected to the first control unit, for controlling the conduction or cut-off of the first control unit; A comparator, connected to the voltage sampling circuit and the second control unit, for comparing a first divided voltage value and a second divided voltage value, and controlling the conduction or cut-off of the second control unit according to the comparison result, where the first divided voltage value is obtained based on the voltage of the first input source, and the second divided voltage value is obtained based on the voltage of the first output source.

2. The boost circuit according to claim 1, wherein The Z-source circuit includes: A first inductor, whose first end is connected to the positive pole of the first input source; A first diode, whose positive pole is connected to the second end of the first inductor; A second inductor, whose first end is connected to the negative pole of the first diode; A second diode, whose positive pole is connected to the second end of the second inductor, and whose negative pole is connected to the positive pole of the first output source; A first capacitor, whose positive pole is connected to the negative pole of the first diode and the first end of the second inductor, and whose negative pole is connected to the negative pole of the first input source; A second capacitor, whose negative pole is connected to the second end of the first inductor and the positive pole of the first diode, and whose positive pole is connected to the second end of the second inductor and the positive pole of the second diode; A third capacitor, whose positive pole is connected to the negative pole of the second diode and the positive pole of the first output source, and whose negative pole is connected to the negative pole of the first capacitor and the negative pole of the first output source.

3. The boost circuit according to claim 2, wherein The voltage sampling circuit includes: a first voltage dividing circuit and a second voltage dividing circuit; The first voltage dividing circuit includes: A first resistor, whose first end is connected to the positive pole of the first input source and the first end of the first inductor; A second resistor, whose first end is connected to the second end of the first resistor, and whose second end is connected to the negative end of the first input source, the negative pole of the first capacitor, the negative pole of the third capacitor, and the negative pole of the first output source; The second voltage dividing circuit includes: A third resistor, whose first end is connected to the negative pole of the second diode, the positive pole of the third capacitor, and the positive pole of the first output source; A fourth resistor, whose first end is connected to the second end of the third resistor, and whose second end is connected to the negative pole of the first input source, the negative pole of the third capacitor, the negative pole of the first capacitor, and the negative pole of the first output source.

4. The boost circuit according to claim 3, wherein The non-inverting input terminal of the comparator is connected to the second terminal of the first resistor and the first terminal of the second resistor, and the inverting input terminal is connected to the second terminal of the third resistor and the first terminal of the fourth resistor.

5. The boost circuit according to claim 4, wherein The first control unit includes a first control transistor, whose drain is connected to the second terminal of the second inductor and the positive electrode of the second diode, and whose gate is connected to the output terminal of the comparator.

6. The boost circuit according to claim 5, wherein The second control unit includes a second control transistor, whose drain is connected to the source of the first control transistor, whose source is connected to the first capacitor and the negative electrode of the third capacitor, and whose gate is connected to the controller.

7. The boost circuit according to claim 3, wherein The controller is used to control the first control unit to conduct when the triangular carrier wave is less than the modulation wave; The comparator is used to control the second control unit to conduct when the first divided voltage value is greater than the second divided voltage value; Correspondingly, the first control unit and the second control unit are used to control the Z-source circuit to be in a through state.

8. The boost circuit according to claim 7, wherein The controller is used to control the first control unit to turn off when the triangular carrier wave is greater than the modulation wave; The comparator is used to control the second control unit to conduct when the first divided voltage value is greater than the second divided voltage value; Correspondingly, the first control unit and the second control unit are used to control the Z-source circuit to be in a non-through state.

9. The boost circuit according to claim 3, wherein The controller is used to control the first control unit to conduct when the triangular carrier wave is less than the modulation wave; The comparator is used to control the second control unit to turn off when the first divided voltage value is less than the second divided voltage value; Correspondingly, the first control unit and the second control unit are used to control the Z-source circuit to be in a non-through state.

10. The boost circuit according to claim 9, wherein, The controller is used to control the first control unit to turn off when the triangular carrier wave is greater than the modulation wave; The comparator is used to control the second control unit to turn off when the first divided voltage value is less than the second divided voltage value; Correspondingly, the first control unit and the second control unit are used to control the Z-source circuit to be in a non-through state.

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