Totem column power factor correction circuit, control method, device and equipment

Abstract

The application discloses a totem pole power factor correction circuit, a control method, a device and equipment, the circuit includes a rectifier module, a reactor, a capacitor module, a control module and a switching module, the input end of the rectifier module is connected with an alternating current power supply, and the output end of the rectifier module is used for being connected with a load; the capacitor module is connected with the output end, and includes a first capacitor and a second capacitor in series connection, and the first connection point of the first capacitor and the second capacitor is connected with the alternating current power supply through the switching module; by setting the control module, the rectifier module and the switching module can be controlled according to load parameters, so that the totem pole power factor correction circuit is switched to a synchronous rectification mode or a non-controlled rectification mode, so that the totem pole power factor correction circuit can reduce loss and save resources under the condition that load parameters change, and the circuit efficiency is ensured. The application can be widely applied in the technical field of control.

Description

Technical Field

[0001] This invention relates to the field of control technology, and in particular totem pole power factor correction circuits, control methods, devices and equipment. Background Technology

[0002] In existing electronic power technologies, PFC (Power Factor Correction) circuits are commonly used to provide bus voltage in order to achieve a higher power factor. While some existing totem-pole PFC circuits have a boost function, capable of increasing the rectified output voltage, they cannot achieve a voltage doubled output (i.e., the output voltage is twice the input voltage). Furthermore, they cannot adjust the output according to load requirements under doubled output conditions, leading to a mismatch between the totem-pole PFC circuit's output and load parameters, thus affecting circuit efficiency. Summary of the Invention

[0003] This application provides a totem pole power factor correction circuit, control method, device, and equipment that can ensure the circuit efficiency of the totem pole power factor correction circuit.

[0004] According to a first aspect of the embodiments of this application, a totem pole power factor correction circuit is provided, comprising:

[0005] The rectifier module includes an input terminal and an output terminal, wherein the input terminal is connected to an AC power source and the output terminal is used to connect to a load;

[0006] A reactor is disposed between the rectifier module and the AC power supply;

[0007] Switch module;

[0008] A capacitor module is connected to the output terminal. The capacitor module includes a first capacitor and a second capacitor. The first capacitor and the second capacitor are connected in series. The first connection point of the first capacitor and the second capacitor is connected to the AC power supply through the switch module.

[0009] The control module is used to control the rectifier module and the switching module according to the load parameters of the load, so that the totem pole power factor correction circuit switches to synchronous rectification mode or uncontrolled rectification mode.

[0010] In this embodiment, the rectifier module can be controlled according to the load parameters, so that the totem pole power factor correction circuit can be switched to synchronous rectification mode or uncontrolled rectification mode, thereby enabling the totem pole power factor correction circuit to reduce losses and save resources and ensure circuit efficiency when the load parameters change.

[0011] Optionally, in one embodiment of this application, the rectifier module includes a switching module, a first switching unit, and a second switching unit;

[0012] The first switching unit includes a first power transistor and a first diode. The first diode is connected in antiparallel with the first power transistor, and the cathode of the first diode is connected to the first terminal of the first capacitor.

[0013] The second terminal of the first capacitor is connected to the first terminal of the second capacitor, and the second terminal of the first capacitor is connected to one end of the AC power supply through the switching module.

[0014] The second switching unit includes a second power transistor and a second diode. The second diode is connected in anti-parallel with the second power transistor. The cathode of the second diode is connected to the anode of the first diode. The cathode of the second diode is connected to the other end of the AC power supply. The anode of the second diode is connected to the second terminal of the second capacitor.

[0015] The reactor is disposed between the negative terminal of the second diode and the AC power supply, or between the second terminal of the first capacitor and the AC power supply.

[0016] In this embodiment, the first switching unit includes a first power transistor and a first diode, and the second switching unit includes a second power transistor and a second diode, which can provide different flow paths for the input current of the rectifier module and provide a basis for synchronous rectification or uncontrolled rectification.

[0017] Optionally, in one embodiment of this application, the rectifier module further includes a first power diode and a second power diode;

[0018] The anode of the first power diode is connected to the cathode of the first diode, the cathode of the first power diode is connected to the first terminal of the first capacitor, the anode of the second power diode is connected to the second terminal of the second capacitor, and the cathode of the second power diode is connected to the anode of the second diode.

[0019] In this embodiment, by setting the first power diode and the second power diode, it is possible to prevent backflow when the input voltage of the rectifier module is lower than the bus voltage, thus protecting the totem pole power factor correction circuit; when the switch module is in the normally closed state, it can prevent backflow when the first capacitor and the second capacitor discharge.

[0020] Optionally, in one embodiment of this application, the switching module includes a relay or a switching transistor unit;

[0021] The switching unit includes a third power diode, a fourth power diode, a fifth power diode, a sixth power diode, and a first switching transistor. The third power diode and the fourth power diode are connected in series to form a first power diode branch. The fifth power diode and the sixth power diode are connected in series to form a second power diode branch. The first switching transistor, the first power diode branch, and the second power diode branch are connected in parallel. The connection point between the third power diode and the fourth power diode is led out as one end of the switching module, and the connection point between the fifth power diode and the sixth power diode is led out as the other end of the switching module.

[0022] Alternatively, the switching unit may include a second and a third switching transistor connected in reverse parallel.

[0023] Alternatively, the switching unit may include a fourth and a fifth switching transistor connected in reverse series, and both the fourth and the fifth switching transistors are connected in antiparallel with power diodes.

[0024] In this embodiment, the switch module offers diverse types and strong applicability. When the switch module is a relay, the presence of the first power diode and the second power diode can prevent backflow when the first capacitor and the second capacitor discharge.

[0025] According to a second aspect of the embodiments of this application, a control method is provided, applied to the totem pole power factor correction circuit of the above embodiments, the control method comprising the following steps:

[0026] Obtain the load parameters;

[0027] Once the load parameter is determined to be less than the first threshold, the totem pole power factor correction circuit is controlled to switch to uncontrolled rectification mode;

[0028] Alternatively, if the load parameter is determined to be greater than or equal to the first threshold and less than the second threshold, the totem pole power factor correction circuit can be controlled to switch to synchronous rectification mode.

[0029] In this embodiment, the rectifier module can be controlled according to the load parameters, so that the totem pole power factor correction circuit can be switched to synchronous rectification mode or uncontrolled rectification mode, thereby enabling the totem pole power factor correction circuit to reduce losses and save resources and ensure circuit efficiency when the load parameters change.

[0030] Optionally, in one embodiment of this application, controlling the totem pole power factor correction circuit to switch to synchronous rectification mode includes the following steps:

[0031] The switch module is turned on, and the input voltage of the rectifier module is determined to be within the first time period of the positive half cycle. The first power transistor is turned on, and the second power transistor is turned off, so as to charge the first capacitor.

[0032] The switch module is turned on, and the input voltage of the rectifier module is determined to be in the second time period of the negative half cycle. The second power transistor is turned on, and the first power transistor is turned off, so as to charge the second capacitor.

[0033] In this embodiment of the application, by controlling the first power transistor and the second power transistor, the conduction loss of the diode is reduced and the circuit efficiency is improved.

[0034] Optionally, in one embodiment of this application, controlling the totem pole power factor correction circuit to switch to uncontrolled rectification mode includes the following steps:

[0035] The first power transistor and the second power transistor are turned off, and the switching module is turned on.

[0036] In this embodiment, the first power transistor and the second power transistor are in the off state, which reduces the number of switching cycles and switching losses of the power transistors, thereby improving circuit efficiency.

[0037] Optionally, in one embodiment of this application, the rectifier module further includes a third switching unit and a fourth switching unit. The first switching unit and the second switching unit are connected in series to form a first branch, and the third switching unit and the fourth switching unit are connected in series to form a second branch. The first branch and the second branch are connected in parallel. The common terminal of the third switching unit and the fourth switching unit is connected to the second terminal of the first capacitor through the switching module. The control method further includes the following steps:

[0038] The third switch unit and the fourth switch unit are controlled to turn off.

[0039] In this embodiment, a third switching unit and a fourth switching unit are further provided to form a bridge circuit, which can improve the rectification effect of the rectifier module. In addition, a control method for the third switching unit and the fourth switching unit is provided to meet the needs of different control methods.

[0040] Optionally, in one embodiment of this application, the load parameters include at least one of load current, load power, load operating pressure, and load frequency.

[0041] In the embodiments of this application, at least one of load current, load power, load operating pressure and load frequency can be included, which is more diversified and can meet different needs in actual situations.

[0042] According to a third aspect of the embodiments of this application, an apparatus is provided, comprising:

[0043] At least one processor;

[0044] At least one memory for storing at least one program;

[0045] When the at least one program is executed by the at least one processor, the at least one processor implements the control method described in the second aspect.

[0046] According to a fourth aspect of the embodiments of this application, an apparatus is provided, comprising:

[0047] load;

[0048] The load is driven by the device described in the third aspect.

[0049] According to a fifth aspect of the embodiments of this application, a storage medium is provided, the storage medium storing a program, which, when executed by a processor, is used to implement the control method described in the second aspect.

[0050] The technical solutions provided by the embodiments of this application can switch to synchronous rectification mode according to load parameters, thereby reducing losses (such as diode conduction losses) and ensuring circuit efficiency while meeting load requirements; and can also switch to uncontrolled rectification mode according to load parameters, thereby reducing losses (such as power transistor switching losses) and ensuring circuit efficiency while meeting load requirements. Attached Figure Description

[0051] Figure 1 This is a schematic diagram of the totem pole power factor correction circuit provided in the application embodiment;

[0052] Figure 2(a) shows the first implementation of the switching transistor unit, Figure 2(b) shows the second implementation of the switching transistor unit, and Figure 2(c) shows the third implementation of the switching transistor unit.

[0053] Figure 3 This is a schematic diagram of another totem pole power factor correction circuit provided in the application embodiment;

[0054] Figure 4 This is a flowchart of a control method provided in the application embodiments;

[0055] Figure 5 This is a pulse diagram illustrating the control method of the rectifier module and the switching module in the embodiment of the application.

[0056] Figure 6 This is a schematic diagram of a device in one of the embodiments of the application. Detailed Implementation

[0057] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0058] The terms "first," "second," "third," and "fourth," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0059] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0060] Reference Figure 1 This application provides a totem pole power factor correction circuit, which includes a rectifier module 10, a reactor L, a capacitor module 20, a control module 30, and a switch module.

[0061] The rectifier module 10 includes an input terminal and an output terminal. The input terminal is connected to an AC power supply, and the output terminal is connected to a load.

[0062] The reactor L is positioned between the rectifier module 10 and the AC power supply. One end of the reactor L is connected to the AC power supply, and the other end of the reactor L is connected to the input terminal of the rectifier module 10.

[0063] The capacitor module 20 is connected to the output terminal of the rectifier module 10. The capacitor module 20 includes a first capacitor C1 and a second capacitor C2. The first capacitor C1 and the second capacitor C2 are connected in series. The first connection point a of the first capacitor C1 and the second capacitor C2 is connected to the input terminal of the rectifier module 10.

[0064] The control module 30 is used to control the rectifier module 10 and the switching module according to the load parameters of the load, so that the totem pole power factor correction circuit switches to synchronous rectification mode or uncontrolled rectification mode, thereby enabling the totem pole power factor correction circuit to reduce losses and save resources and ensure circuit efficiency when the load parameters change.

[0065] In this embodiment, the rectifier module 10 may specifically include a bridge circuit, which includes a first switching unit 11, a second switching unit 12, a third switching unit 13, and a fourth switching unit 14. The first switching unit 11 and the second switching unit 12 are connected in series to form a first branch, the third switching unit 13 and the fourth switching unit 14 are connected in series to form a second branch, and the first branch and the second branch are connected in parallel to form a bridge circuit.

[0066] The second connection point b between the first switch unit 11 and the third switch unit 13 is connected to the first terminal of the first capacitor C1, the second terminal of the first capacitor C1 is connected to the first terminal of the second capacitor C2, and the third connection point c between the second switch unit 12 and the fourth switch unit 14 is connected to the second terminal of the second capacitor C2.

[0067] The fourth connection point d of the first switch unit 11 and the second switch unit 12 is connected to one end of the AC power supply, and the fifth connection point e of the third switch unit 13 and the fourth switch unit 14 is connected to the other end of the AC power supply. The fifth connection point e is connected to the second end of the first capacitor C1.

[0068] The first switching unit 11 includes a first power transistor Q1 and a first diode D1 connected in antiparallel to the first power transistor Q1; the second switching unit 12 includes a second power transistor Q2 and a second diode D2 connected in antiparallel to the second power transistor Q2; the third switching unit 13 includes a third power transistor Q3 and a third diode D3 connected in antiparallel to the third power transistor Q3; and the fourth switching unit 14 includes a fourth power transistor Q4 and a fourth diode D4 connected in antiparallel to the fourth power transistor Q4.

[0069] In this embodiment, the fifth connection point e is connected to the second terminal of the first capacitor C1 via the switch module Q5. The switch module Q5 has bidirectional conduction functionality and is positioned between the first connection point a and the fifth connection point e. Specifically, one end of the switch module Q5 is connected to the fifth connection point e, and the other end is connected to the second terminal of the first capacitor, i.e., the first connection point a. The switch module Q5 enables control in both synchronous rectification and uncontrolled rectification modes, and allows the totem-pole power factor correction circuit to switch to a general operating mode other than the voltage multiplication mode. For example, the switch module Q5 can be used when the input voltage of the bridge circuit is turned off during both the positive and negative half-cycles.

[0070] Optionally, in this embodiment, the switching module Q5 includes, but is not limited to, various implementations, such as a relay or a switching transistor unit, wherein the switching transistor unit includes, but is not limited to, one of the following implementations:

[0071] 1) As shown in Figure 2(a), the switching unit includes a fifth power diode D7, a sixth power diode D8, a seventh power diode D9, an eighth power diode D10, and a first switching transistor Q6. The fifth power diode D7 and the sixth power diode D8 are connected in series to form the first branch of the power diodes. The seventh power diode D9 and the eighth power diode D10 are connected in series to form the second branch of the power diodes. The first switching transistor Q6, the first branch of the power diodes, and the second branch of the power diodes are connected in parallel. The connection point of the fifth power diode D7 and the sixth power diode D8 is led out as one end of the switching module, and the connection point of the seventh power diode D9 and the eighth power diode D10 is led out as the other end of the switching module. The first switching transistor Q6 is turned on when the switching module is turned on, and the first switching transistor Q6 is turned off when the switching module is turned off.

[0072] 2) As shown in Figure 2(b), the switching unit includes a second switch Q7 and a third switch Q8 connected in reverse parallel; wherein the switching module is turned on when the second switch Q7 is turned on and the third switch Q8 is turned off, or the second switch Q7 is turned off and the third switch Q8 is turned on, and the switching module is turned off when both the second switch Q7 and the third switch Q8 are turned off.

[0073] 3) As shown in Figure 2(c), the switching unit includes a fourth switch Q9 and a fifth switch Q10 connected in reverse series. Both the fourth switch Q9 and the fifth switch Q10 are connected in antiparallel with power diodes (the ninth power diode D11 and the tenth power diode D12, respectively). The switching module is turned on when the fourth switch Q9 is turned on and the fifth switch Q10 is turned off, or when the fourth switch Q9 is turned off and the fifth switch Q10 is turned on. The switching module is turned off when both the fourth switch Q9 and the fifth switch Q10 are turned off.

[0074] Alternatively, in some other embodiments, the third switch unit 13 and the fourth switch unit 14 may not be provided.

[0075] It is understood that in other embodiments, the rectifier module 10 is not limited to the above structure and can be flexibly selected and set; the first power transistor Q1, the second power transistor Q2, the third power transistor Q3 and the fourth power transistor Q4 include, but are not limited to, metal oxide semiconductor field-effect transistors (MOSFETs), insulated gate bipolar transistors (IGBTs), gallium nitride (GaN) power transistors, SiC (silicon carbide) power transistors, etc.

[0076] like Figure 1As shown, in this embodiment, the rectifier module 10 further includes a first power diode D5 and a second power diode D6. The second connection point b is connected to the first terminal of the first capacitor C1 via the first power diode D5, and the third connection point c is connected to the second terminal of the second capacitor C2 via the second power diode D6. Specifically, the anode of the first power diode D5 is connected to the second connection point b, the cathode of the first power diode D5 is connected to the first terminal of the first capacitor C1, the anode of the second power diode D6 is connected to the second terminal of the second capacitor C2, and the cathode of the second power diode D6 is connected to the third connection point c.

[0077] In this embodiment, the first power diode D5 and the second power diode D6 can prevent backflow when the input voltage of the rectifier module 10 is lower than the bus voltage, thereby protecting the totem pole power factor correction circuit. By setting the first power diode D5 and the second power diode D6, even if the switch module Q5 is in a normally closed state, backflow can be prevented when the first capacitor C1 and the second capacitor C2 are discharging, for example, when the type of the switch module Q5 is a relay and the relay is in a normally closed state.

[0078] In this embodiment, the rectifier module 10 has a first input terminal and a second input terminal, and an output terminal including a first output terminal and a second output terminal; wherein the first input terminal is the fourth connection point d, the second input terminal is the fifth connection point e, the first output terminal is the second connection point b, and the second output terminal is the third connection point c.

[0079] The reactor L is specifically located between the fourth connection point d and the AC power supply AC. In other embodiments, the reactor L may be located between the fifth connection point e and the AC power supply AC.

[0080] In this embodiment, the control module 30 includes an AC voltage detection unit 31, a current detection unit 32, a control unit 33, and a DC voltage detection unit 34. It is understood that the control module 30 may also include other detection units (not shown) for acquiring load parameters, such as load parameters including but not limited to one or more of load current, load power, load operating pressure, and load frequency.

[0081] The current detection unit 32 is electrically connected to the input terminal of the rectifier module 10 and is used to detect the input current Is of the rectifier module 10, that is, the input current Is of the bridge circuit.

[0082] The AC voltage detection unit 31 is electrically connected to the input terminal of the rectifier module 10 and is used to detect the input voltage (i.e., the voltage Us of the AC power supply VC) at the input terminal of the rectifier module 10.

[0083] The DC voltage detection unit 34 is electrically connected to the input terminal of the load and is used to detect the bus voltage of the load, i.e. the required voltage of the load.

[0084] The control unit 33 is connected to the current detection unit 32, the junction voltage detection unit and the DC voltage detection unit 34, and can also be further connected to other detection units. It is used to control the on and off states of the rectifier module according to the load parameters, so that the totem pole power factor correction circuit can be switched to synchronous rectification mode or uncontrolled rectification mode.

[0085] In this embodiment, the totem pole power factor correction circuit operates in voltage doubling mode to achieve the voltage doubling function, that is, to make the bus voltage of the connected load twice the input voltage of the rectifier module 10. The synchronous rectification mode and the uncontrolled rectification mode are two working modes in the voltage doubling mode.

[0086] like Figure 3 As shown, it is understood that in some other embodiments, the rectifier module 10 may not include the first power diode D5 and the second power diode D6. The second connection point b can be connected to the first terminal of the first capacitor C1 via a wire, and the third connection point c can be connected to the second terminal of the second capacitor C2 via a wire. It is understood that in this case, the corresponding switching module Q5 is configured as the aforementioned switching transistor unit.

[0087] Reference Figure 4 This application also provides a control method for a totem pole power factor correction circuit, comprising the following steps:

[0088] S1. Obtain load parameters;

[0089] S2. Determine that the load parameters are less than the first threshold, and control the totem pole power factor correction circuit to switch to uncontrolled rectification mode;

[0090] or,

[0091] Once the load parameters are determined to be greater than or equal to the first threshold and less than the second threshold, the totem pole power factor correction circuit is switched to synchronous rectification mode.

[0092] The totem pole power factor correction circuit is the same as the totem pole power factor correction circuit in the above embodiment.

[0093] In this embodiment, the load parameters include at least one of load current, load power, load operating pressure, and load frequency. The load operating pressure and load frequency are the operating pressure and frequency of specific types of loads. For example, if the load includes a compressor, the load operating pressure is the compressor operating pressure, and the load frequency is the compressor frequency. Load parameters can include one of load current, load power, load operating pressure, and load frequency. When the load parameters include more than one of these indicators, the load parameters can be determined by calculation by combining more than one indicator. For example, if the load parameters include load current and load power, the following methods can be used, including but not limited to: setting a first weight for the load current, setting a second weight for the load power, and performing a weighted calculation based on the first weight, load current, second weight, and load power to determine the load parameters. Similarly, if the load parameters include load current, load power, and load operating pressure, corresponding weights can be set, and then a weighted calculation can be performed to determine the load parameters. The required indicators and corresponding weights can be flexibly adjusted according to actual needs, and the load parameters can be determined by combining the required indicators. Optionally, the parameters of the load actually driven by the totem-pole power factor correction circuit can also be determined using, but not limited to, the methods described above.

[0094] The first threshold P1 and the second threshold P2 can be reasonably set according to the load parameters and the requirements of the totem pole power factor correction circuit. For example, load parameters include load frequency. When the load frequency is at a first frequency, the load is considered low, and the first frequency is used as the first threshold P1; when the load frequency is at a second frequency, the load is considered heavy, and the second frequency is used as the second threshold P2. Or, load parameters include load current. When the load current is at a first current value, the load is considered low, and the first current value is used as the first threshold P1; when the load current is at a second current value, the load is considered heavy, and the second current value is used as the third threshold P2. The terms "low load" and "heavy load" can be reasonably adjusted according to actual needs and circumstances, without specific limitations. When load parameters include other indicators, a similar method can be used to determine them, and they can also be reasonably adjusted according to actual needs and circumstances.

[0095] By controlling the load parameter P (i.e. the parameter of the load actually driven by the totem pole power factor correction circuit), when P < P1, the circuit switches to uncontrolled rectification mode. This reduces the number of switching operations and switching losses of the rectifier module while meeting the current load requirements, thus improving circuit efficiency and reducing the complexity of the control module, saving costs. When P1 ≤ P < P2, the circuit switches to synchronous rectification mode. This reduces the conduction losses of the diodes while meeting the load requirements, ensuring circuit efficiency.

[0096] It is understandable that uncontrolled rectification involves significant diode conduction losses, while synchronous rectification involves power transistor conduction and switching losses. In low-load applications, such as loads less than P1, the diode conduction losses in uncontrolled rectification are less than the total losses in synchronous rectification. Therefore, operating in uncontrolled rectification, while meeting current load parameters, reduces power transistor conduction and switching losses compared to synchronous rectification, thus reducing total losses, ensuring circuit efficiency, and reducing the complexity of the control module 30, saving costs. However, in high-current applications, such as loads greater than P1 but less than P2, the increased diode conduction losses result in higher losses in uncontrolled rectification than in synchronous rectification. Therefore, operating in synchronous rectification, while meeting current load parameters, reduces diode conduction losses compared to uncontrolled rectification, thus reducing total losses and ensuring circuit efficiency. Therefore, the switching between uncontrolled and synchronous rectification based on load parameters provided in this embodiment of the invention can guarantee circuit efficiency and optimize it as much as possible.

[0097] The control method in this application will be described below with reference to the totem pole power factor correction circuit embodiment described above.

[0098] Reference Figure 1 and Figure 5 , Figure 5 This is a pulse diagram illustrating the control methods for the rectifier module and the switching module in the application embodiment, specifically a pulse diagram illustrating the control methods for the bridge circuit.

[0099] When P1≤P<P2, the totem pole power factor correction circuit switches to synchronous rectification mode. The specific control process is as follows:

[0100] When the control switch module Q5 is turned on, and the input voltage Us of the bridge circuit (i.e., the input voltage Us of the rectifier module 10) is in the positive half-cycle, after the input voltage Us crosses zero and is delayed for a period of time (specifically within the first time period TA of the positive half-cycle), the first switch unit 11 is turned on, and the second switch unit 12, the third switch unit 13 and the fourth switch unit 14 are turned off, so that the input current passes through the reactor L, the first switch unit 11, the first power diode D5 and the first capacitor C1 to charge the first capacitor C1;

[0101] When the control switch module Q5 is turned on, and the input voltage Us of the bridge circuit is in the negative half-cycle, after the input voltage Us crosses zero and is delayed for a period of time (specifically within the second time period TB of the negative half-cycle), the control switch unit 12 is turned on, and the control switch unit 11, the third switch unit 13 and the fourth switch unit 14 are turned off, so that the input current passes through the second capacitor C2, the second power diode D6, the second switch unit 12 and the reactor L to charge the second capacitor C2.

[0102] It is understood that after the input voltage Us crosses zero, the first switching unit 11 is controlled to turn on after a certain delay. This delay includes, but is not limited to, the time elapsed from when the input voltage Us crosses zero until current is detected in the first diode connected in parallel with the first switching unit 11; the first time period TA includes, but is not limited to, the time elapsed from when current is detected in the first diode connected in parallel with the first switching unit 11 until that current becomes zero. After the input voltage Us crosses zero, the second switching unit 12 is controlled to turn on after a certain delay. This delay includes, but is not limited to, the time elapsed from when the input voltage Us crosses zero until current is detected in the second diode connected in parallel with the second switching unit 12; the second time period TB includes, but is not limited to, the time elapsed from when current is detected in the second diode connected in parallel with the second switching unit 12 until that current becomes zero.

[0103] It is understandable that if the rectifier module 10 does not include the third switch unit 13 and the fourth switch unit 14, then there is no switch control for the third switch unit 13 and the fourth switch unit 14. In this case, what is needed is to control the switch state of the first switch unit 11 and the second switch unit 12.

[0104] When P < P1, the totem pole power factor correction circuit switches to uncontrolled rectification mode. The specific control process is as follows: the first power transistor Q1, the second power transistor Q2, the third power transistor Q3 and the fourth power transistor Q4 are turned off, and the switch module Q5 is turned on.

[0105] It is understandable that the aforementioned control switch module Q5 can be turned on when the input voltage Us of the bridge circuit is in the positive half-cycle or when the input voltage Us of the bridge circuit is in the negative half-cycle, or the switch module Q5 can be turned on in advance, for example, when the switch module Q5 is a relay, the switch module Q5 is kept in the normally closed state.

[0106] Specifically, when the input voltage Us of the bridge circuit (i.e. the input voltage Us of the rectifier module 10) is in the positive half-cycle, the input current passes through the reactor L, the first diode D1, the first power diode D5 and the first capacitor C1 to charge the first capacitor C1.

[0107] When the input voltage Us of the bridge circuit is in the negative half-cycle, the input current passes through the second capacitor C2, the second power diode D6, the second diode D2 and the reactor L, charging the second capacitor C2.

[0108] It is understandable that if the rectifier module 10 does not include the third switch unit 13 and the fourth switch unit 14, then there is no switch control for the third power transistor Q3 and the fourth power transistor Q4. In this case, what is needed is to control the switch states of the first power transistor Q1 and the second power transistor Q2.

[0109] In the embodiments of the present invention, it can be understood that turning off the control switching unit (specifically the power transistor) is equivalent to not needing to provide a driving signal for the switching unit (specifically the power transistor).

[0110] In this example, such as Figure 1 The circuit shown allows the switching module Q5 to be in the form of a switching transistor or a relay, due to the presence of the first power diode D5 and the second power diode D6. When the relay is in the normally closed state, the first power diode D5 and the second power diode D6 can prevent backflow when the first capacitor C1 and the second capacitor C2 are discharging.

[0111] In other embodiments, as shown in Figure 2, the control method is the same as the control method described above. The difference is that since the first power diode D5 and the second power diode D6 are not provided, the switching module Q5 needs to be set as the aforementioned switching transistor and cannot be in a normally closed state.

[0112] To provide a clearer description of the embodiments of the present invention, taking an example where the load includes an inverter module and a compressor, and the load parameter is the load current, the implementation process of this control method is as follows:

[0113] When the bus voltage, i.e., the voltage required by the load, is detected to be greater than twice the peak AC voltage, the totem-pole power factor correction circuit enters voltage doubling mode. In other words, at this time, the totem-pole power factor correction circuit functions as follows: Figure 1 The state shown, or the state when switch module Q5 is closed as shown in Figure 2;

[0114] Detect load current;

[0115] If the load current is less than the first threshold P1, the totem pole power factor correction circuit is controlled in uncontrolled rectification mode. At this time, the switching module Q5 is turned on, and the first power transistor Q1, the second power transistor Q2, the third power transistor Q3 and the fourth power transistor Q4 are turned off, thereby reducing the switching losses of the power transistors and ensuring circuit efficiency. Specifically, when the input voltage of the rectifier module 10 is in the positive half-cycle, the first capacitor C1 is charged, and when the input voltage of the rectifier module 10 is in the negative half-cycle, the second capacitor C2 is charged, which can meet the needs of the inverter module and the compressor.

[0116] When the first threshold P1 ≤ load current < second threshold P2, the totem pole power factor correction circuit is controlled to be in synchronous rectification mode, and the switch module Q5 is turned on. When the input voltage of the rectifier module 10 is in the positive half cycle, the first power transistor Q1 is turned on, and the second power transistor Q2, the third power transistor Q3 and the fourth power transistor Q4 are turned off to charge the first capacitor C1.

[0117] When the control switch module Q5 is turned on, and the input voltage of the rectifier module 10 is in the negative half-cycle, the control switch module Q2 is turned on, which turns off the first power transistor Q1, the third power transistor Q3 and the fourth power transistor Q4, charging the second capacitor C2 to meet the needs of the inverter module and the compressor, and can reduce the conduction loss of the diode and ensure circuit efficiency.

[0118] Reference Figure 5 This application also provides an apparatus, comprising:

[0119] At least one processor 100;

[0120] At least one memory 200 is used to store at least one program;

[0121] When at least one program is executed by at least one processor 100, the at least one processor 100 implements the control method described above.

[0122] The content of the above method embodiments is applicable to the device embodiments. The specific functions implemented by the device embodiments are the same as those of the above method embodiments, and the beneficial effects achieved are also the same as those achieved by the above method embodiments.

[0123] This invention also provides a device comprising:

[0124] load;

[0125] The load is driven by the aforementioned device.

[0126] The drive can include indirect drive and direct drive. For example, if the load is a DC drive, it can be directly connected to the output terminal of the rectifier module 10 for direct drive. If the load is an AC drive, it can include a primary load and a secondary load, with the primary load connected to the secondary load and the primary load connected to the output terminal of the rectifier module 10. For example, the primary load can be an inverter module and the secondary load can be a compressor, but in other embodiments, it is not limited to these.

[0127] The content of the above method embodiments is applicable to this device embodiment. The specific functions implemented in this device embodiment are the same as those in the above method embodiments, and the beneficial effects achieved are also the same as those achieved in the above method embodiments.

[0128] This invention also provides a storage medium storing a program, which, when executed by a processor, is used to implement the control method described above.

[0129] The content of the above method embodiments is applicable to this storage medium embodiment. The specific functions implemented in this storage medium embodiment are the same as those in the above method embodiments, and the beneficial effects achieved are also the same as those achieved in the above method embodiments.

[0130] It is understood that all or some of the steps and systems in the methods disclosed above can be implemented as software, firmware, hardware, and suitable combinations thereof. Some or all of the physical components can be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on a computer-readable medium, which can include computer storage media (or non-transitory media) and communication media (or transient media). As is known to those skilled in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disc (DVD) or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and is accessible to a computer. Furthermore, as is known to those skilled in the art, communication media typically contain computer-readable instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium.

[0131] 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.

Claims

1. A totem pole power factor correction circuit, characterized in that, include: The rectifier module includes an input terminal and an output terminal. The input terminal is connected to an AC power supply, and the output terminal is used to connect to a load. The rectifier module also includes a first switching unit and a second switching unit. The first switching unit includes a first power transistor and a first diode, and the first diode is connected in antiparallel to the first power transistor. The second switching unit includes a second power transistor and a second diode, and the second diode is connected in antiparallel to the second power transistor. The cathode of the second diode is connected to the anode of the first diode. A reactor is disposed between the rectifier module and the AC power supply; Switch module; A capacitor module is connected to the output terminal. The capacitor module includes a first capacitor and a second capacitor. The first capacitor and the second capacitor are connected in series. The first connection point of the first capacitor and the second capacitor is connected to the AC power supply through the switch module. The control module is used to acquire the load parameters when the required voltage of the load is greater than twice the peak value of the AC voltage; If the load parameter is less than the first threshold, control the rectifier module and the switch module to switch the totem pole power factor correction circuit to uncontrolled rectification mode; Alternatively, if the load parameter is greater than or equal to the first threshold and less than the second threshold, control the rectifier module and the switch module to switch the totem pole power factor correction circuit to synchronous rectification mode; The step of controlling the rectifier module and the switching module to switch the totem pole power factor correction circuit to synchronous rectification mode includes: The switch module is controlled to turn on, and the input voltage of the rectifier module is determined to be in the positive half-cycle and within a first time period after the voltage zero crossing point. The first power transistor is controlled to turn on, and the second power transistor is controlled to turn off, so as to charge the first capacitor. The first time period is the time elapsed from when a current is detected between the first diode and the first diode until the current becomes zero. The switch module is controlled to turn on, and the input voltage of the rectifier module is determined to be in the negative half-cycle and in the second time period after the voltage zero crossing point. The second power transistor is controlled to turn on, and the first power transistor is controlled to turn off, so as to charge the second capacitor. The second time period is the time elapsed from when a current is detected between the second diode and the current becomes zero.

2. The totem pole power factor correction circuit according to claim 1, characterized in that: The negative terminal of the first diode is connected to the first terminal of the first capacitor; the second terminal of the first capacitor is connected to the first terminal of the second capacitor, and the second terminal of the first capacitor is connected to one end of the AC power supply through the switching module. The cathode of the second diode is connected to the anode of the first diode, the cathode of the second diode is connected to the other end of the AC power supply, and the anode of the second diode is connected to the second terminal of the second capacitor. The reactor is disposed between the negative terminal of the second diode and the AC power supply, or between the second terminal of the first capacitor and the AC power supply.

3. The totem pole power factor correction circuit according to claim 2, characterized in that: The rectifier module further includes a first power diode and a second power diode; The anode of the first power diode is connected to the cathode of the first diode, the cathode of the first power diode is connected to the first terminal of the first capacitor, the anode of the second power diode is connected to the second terminal of the second capacitor, and the cathode of the second power diode is connected to the anode of the second diode.

4. The totem pole power factor correction circuit according to any one of claims 1-3, characterized in that: The switching module includes a relay or a switching transistor unit; The switching unit includes a third power diode, a fourth power diode, a fifth power diode, a sixth power diode, and a first switching transistor. The third power diode and the fourth power diode are connected in series to form a first power diode branch. The fifth power diode and the sixth power diode are connected in series to form a second power diode branch. The first switching transistor, the first power diode branch, and the second power diode branch are connected in parallel. The connection point between the third power diode and the fourth power diode is led out as one end of the switching module, and the connection point between the fifth power diode and the sixth power diode is led out as the other end of the switching module. Alternatively, the switching unit may include a second and a third switching transistor connected in reverse parallel. Alternatively, the switching unit may include a fourth and a fifth switching transistor connected in reverse series, and both the fourth and the fifth switching transistors are connected in antiparallel with power diodes.

5. A control method, characterized in that, The control method, applied to the totem pole power factor correction circuit as described in any one of claims 1-4, includes the following steps: The load parameters are obtained when the required voltage of the load is greater than twice the peak AC voltage. Once the load parameter is determined to be less than a first threshold, the rectifier module and the switch module are controlled to switch the totem pole power factor correction circuit to uncontrolled rectification mode. Alternatively, if the load parameter is determined to be greater than or equal to the first threshold and less than the second threshold, the rectifier module and the switch module are controlled to switch the totem pole power factor correction circuit to synchronous rectification mode. The step of controlling the rectifier module and the switching module to switch the totem pole power factor correction circuit to synchronous rectification mode includes the following steps: The switch module is controlled to turn on, and the input voltage of the rectifier module is determined to be in the positive half-cycle and within a first time period after the voltage zero crossing point. The first power transistor is controlled to turn on, and the second power transistor is controlled to turn off, so as to charge the first capacitor. The first time period is the time elapsed from when a current is detected between the first diode and the first diode until the current becomes zero. The switch module is controlled to turn on, and the input voltage of the rectifier module is determined to be in the negative half-cycle and in the second time period after the voltage zero crossing point. The second power transistor is controlled to turn on, and the first power transistor is controlled to turn off, so as to charge the second capacitor. The second time period is the time elapsed from when a current is detected between the second diode and the current becomes zero.

6. The control method according to claim 5, characterized in that: The process of controlling the totem pole power factor correction circuit to switch to uncontrolled rectification mode includes the following steps: The first power transistor and the second power transistor are turned off, and the switching module is turned on.

7. The control method according to any one of claims 5-6, characterized in that: The rectifier module further includes a third switching unit and a fourth switching unit. The first switching unit and the second switching unit are connected in series to form a first branch, and the third switching unit and the fourth switching unit are connected in series to form a second branch. The first branch and the second branch are connected in parallel. The common terminal of the third switching unit and the fourth switching unit is connected to the second terminal of the first capacitor through the switching module. The control method further includes the following steps: The third switch unit and the fourth switch unit are controlled to turn off.

8. The control method according to any one of claims 5-6, characterized in that: The load parameters include at least one of the following: load current, load power, load operating pressure, and load frequency.

9. An apparatus, characterized in that, include: At least one processor; At least one memory for storing at least one program; When the at least one program is executed by the at least one processor, the at least one processor implements the control method as described in any one of claims 5-8.

10. A device, characterized in that, include: load; The load is driven by the device as described in claim 9.

11. A storage medium, characterized in that, The storage medium stores a program that, when executed by a processor, is used to implement the control method as described in any one of claims 5-8.

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