CN113162439A

CN113162439A - Half-wave symmetric converter and control method

Info

Publication number: CN113162439A
Application number: CN202110271638.9A
Authority: CN
Inventors: 严宗周
Original assignee: Shenzhen Yuanneng Electric Appliance Co ltd
Current assignee: Shenzhen Yuanneng Electric Appliance Co ltd
Priority date: 2021-03-12
Filing date: 2021-03-12
Publication date: 2021-07-23
Also published as: WO2022188853A1

Abstract

The invention discloses a half-wave symmetrical converter and a control method, wherein the half-wave symmetrical converter consists of a first half-wave rectifying circuit and a second half-wave rectifying circuit, the half-wave rectifying circuit consists of any one or two of a diode and a switching tube, the two half-wave rectifying circuits are electrically connected with the input end of an alternating current bus and are respectively connected with sine waves of the upper half cycle and the lower half cycle for rectification, and then the rectified current is output; further complete functions such as a control circuit, a potential energy conversion unit, a booster circuit and the like can be added according to needs, and a single-stage PFC converter can be formed by adding the PFC unit; and a control method of the device and a control method after the device is added into a PFC unit are as follows: the sine wave of a single period is divided into a plurality of nodes, and the energy output and distribution in each stage are further controlled according to the node division stage. The utility model has the advantages of realize carrying out effectual rectification and reducing whole consumption, volume to the commercial power, through adding the PFC unit, provide stable, reliable output.

Description

Half-wave symmetric converter and control method

Technical Field

The invention relates to the technical field of converters, in particular to a half-wave symmetric converter and a control method.

Background

In the conventional medium-large power supply, a normal structure needs to be rectified firstly and then output in multiple paths or single path, two paths of positive and negative half cycles are needed during bridge rectification, and two pipes in each path are connected in series, so that the power consumed by rectification is large; for example, a 100W power supply, requires about 1.8W of power at low voltage input, just the rectifier bridge.

In order to effectively utilize a power grid, many products in the prior art need high power factors, such as a power supply of an LED lamp and a power supply of more than 75W, in order to realize a high PF, two-pole conversion is usually required, a voltage is increased to increase a PF value, and then voltage reduction or voltage increase conversion is performed, two conversions require two inductors or one inductor and one transformer, and the design not only wastes part of energy but also causes the total volume to be increased. The conventional single-stage PFC in the market has the defects that the output current has large work frequency fluctuation according to P-U-I due to the fact that the current and the voltage are in the same phase; the other mode is a valley-filling type non-stroboscopic single-stage PFC converter, but a PFC capacitor arranged behind a bridge stack of the converter is not easy to select on the aspects of energy storage time and energy storage size and difficult to effectively control, and the PFC capacitor starts to be charged in a boosting stage until a peak value is cut off at 90 degrees, so that the PF value cannot be very high, the actual use effect is relatively poor, and the service life is short; the other one is connecting the rectifier tube to the winding, stringing a capacitor to store energy, this kind of structure, because this kind of scheme can't control the charging time to energy storage capacitor, lead to the very big energy storage of stage electric capacity that rises equally, can't store energy after 90 degrees of peak value, lead to the electric current serious deformation, can't accomplish high PF value, and capacitor voltage can only equal input voltage and winding voltage, lead to voltage height life weak point.

Accordingly, there is a need for a half-wave symmetrical converter and a control method that address one or more of the above problems.

Disclosure of Invention

The invention provides a half-wave symmetric converter and a control method thereof, aiming at solving one or more problems in the prior art. The technical scheme adopted by the invention for solving the problems is as follows: a half-wave symmetric converter, comprising: the half-wave rectifier circuit comprises a first half-wave rectifier circuit and a second half-wave rectifier circuit, wherein the first half-wave rectifier circuit and the second half-wave rectifier circuit are composed of any one or two of a diode and a switching tube;

the first half-wave rectifying circuit and the second half-wave rectifying circuit are connected in parallel at an alternating current input end, one sine wave period of the alternating current input end is divided into a positive half cycle and a negative half cycle, one half cycle is connected into the first half-wave rectifying circuit, and the other half cycle of the alternating current input end is connected into the second half-wave rectifying circuit;

the other end of the two half-wave rectification circuits is electrically connected with a load or a converter, so that a complete input waveform is formed for alternating current, and primary rectification is omitted.

Further, comprising: a control circuit and a potential energy conversion unit,

the control circuit is formed by combining a switching tube and/or a diode;

the potential energy conversion units are inductors or transformers, and two groups of potential energy conversion units are arranged;

the control circuit is connected with the first half-wave circuit and the potential energy conversion unit in a control mode to form a first loop; the control circuit is connected with a second half-wave circuit and the other potential energy conversion unit in a control mode to form a second loop, and two paths of the potential energy conversion unit are symmetrical to form a half-wave symmetrical converter;

the first loop circuit and the second loop circuit are set to be any one of a booster circuit, a voltage reduction circuit, a voltage boosting circuit, a forward circuit and a flyback circuit according to requirements;

and combining the two outputs of the first loop and the second loop into one output circuit according to the requirement.

Furthermore, the first half-wave rectification circuit and the second half-wave rectification circuit are connected to different input end windings of the same magnetic core transformer in a reversing mode, a first half cycle and a second half cycle are alternated on the voltage waveform corresponding to the input voltage, and secondary sides form output voltages with the same phase.

Further, still include: the PFC unit is provided with an energy storage capacitor and at least one switching tube, and the position where the PFC unit is placed comprises one or more of the following three types of combinations:

the first method is that the first half-wave rectification circuit and/or the second half-wave rectification circuit are electrically connected;

the second method is electrically connected between the first half-wave rectifying circuit and the second half-wave rectifying circuit;

and in the third method, the electric connection is between the winding and the ground.

And a control method of a half-wave symmetric converter, dividing the following nodes by taking 0 to 360 degrees of a rectified sine wave as a cycle period:

t0, T0 is the lowest valley point of voltage;

t1, T1 is set in the voltage rising phase, the voltage at T1 is greater than that at T0, and the voltage is a positive half-cycle low-voltage rising point;

t2, T2 is set in the voltage rising phase, the voltage at T2 is greater than that at T1, and the voltage is a positive half-cycle boosting high-voltage point;

t3, T3 is a positive half-cycle high voltage point, and the voltage at T3 is greater than that at T2;

t4, T4 is set in a voltage drop phase, the voltage at T4 is smaller than that at T3, and a positive half cycle step-down high voltage point is formed;

t5, T5 is set in a voltage drop phase, the voltage at T5 is smaller than that at T4, and is a positive half-cycle low-voltage drop point;

the following is 180-degree and 360-degree negative half-cycle node division, which is convenient for the description of half-wave symmetrical single-stage PFC control, and the negative half-cycle voltage is the voltage of the absolute value:

t0, T0 is a commutation node of 0 degree, 180 degrees and 360 degrees;

T1A, T1A is set in the voltage rising phase, the voltage at T1A is greater than that at T0, and is a negative half-cycle low-voltage rising point;

T2A, T2A is set in the voltage rising phase, the voltage at T2A is greater than that at T1A, and the voltage is a negative half-cycle boosting high-voltage point;

T3A, T3A is a negative half-cycle high voltage point, and the voltage at T3A is greater than that at T2A;

T4A, T4A is set in a voltage drop phase, the voltage at T4A is smaller than the voltage at T3A, and is a negative half-cycle voltage drop high-voltage point;

T5A, T5A is set in a voltage drop stage, the voltage at T5A is smaller than the voltage at T4A, and is a negative half-cycle low-voltage step-down point;

charging the PFC unit in a boosting or high-voltage stage according to different positions of the PFC unit;

in the valley stage: and in any one or more stages of T4-T2 stage, T4A-T2A stage, T5-T1 stage and T5A-T1A stage, the PFC unit releases electric energy to fill the valley.

Further, when the PFC unit is arranged on the input bus, the second loop is conducted for a long time or intermittently conducted to charge the PFC unit in a boosting stage of T0-T3, T0-T3A, T1-T3, T1A-T3A, T2-T3 and T2A-T3A or one of high-voltage stages of T2-T4 and T2A-T4A.

Further, when the PFC unit is arranged between the winding and the ground, the PFC unit is charged in an energy storage mode in the input sine wave peak time stages T2-T4 and T2A-T4A as follows:

when the voltage of the PFC unit is lower than the input voltage, the control unit controls the input to distribute energy to the PFC unit and the potential energy conversion unit according to the requirement;

in the voltage rising stage, the proportion of the energy input and distributed to the PFC unit is gradually increased, namely the conduction time of the PFC unit is increased;

in the voltage reduction stage, the proportion of the energy input and distributed to the PFC unit is gradually reduced, namely the conduction time of the PFC unit is reduced;

the proportion of energy distribution is controlled by controlling the on-time to the PFC unit.

Further, in the stages of T2-T4 and T2A-T4A, when the voltage of the PFC unit is higher than the input voltage, the PFC unit is led through the first loop or the second loop, the input energy is stored in the potential energy conversion unit, then the first loop or the second loop is closed, the current of the potential energy conversion unit is changed from increasing to decreasing, the windings form back pressure, and then the regulation is performed by any one of the following modes:

the first method is as follows: the PFC unit is conducted, the energy of the whole switching period is stored in the PFC unit or directly transmitted to a secondary, and the processing of the mode I is carried out by adopting one period or repeating more than one period;

the second method comprises the following steps: sequentially distributing the energy stored in the potential energy conversion unit for a single time to the PFC unit and the output;

the proportion stored in the PFC unit is increased along with the increase of the input voltage, and the proportion stored in the PFC unit is reduced along with the decrease of the input voltage.

Further, in the valley period, namely one of the stages T5-T1, T5A-T1A and/or T4-T2 and T4A-T2A, the PFC unit and the input are connected in any one of parallel connection, series connection and series-parallel combination, then the input is combined with the potential energy conversion unit to be subjected to valley filling output, and the input is transmitted to the output through the potential energy conversion unit.

Further, an ACF module and a multi-output module are added according to needs.

The invention has the advantages that the first half-wave rectification circuit, the second half-wave rectification circuit, the control circuit and the potential energy conversion unit are arranged in the converter, so that the rectification waveform can be obtained by only one rectification tube or synchronous tube in a half rectification period, and the isolated output can be realized by one transformer through the reversing access of two different windings; a PFC unit can be arranged as required to form a single-stage PFC converter, and the rectifier tubes are reduced to reduce power consumption, improve energy conversion efficiency and reduce the whole volume; and the control method of the cooperation is as follows: the method comprises the following steps of dividing a single period of a mains supply into a plurality of nodes, integrating the nodes into a plurality of time periods, controlling other units and components to work by a control circuit according to the time periods, realizing the processes of regulation and rectification, input and output, and regulating by matching with a PFC unit, realizing that redundant energy in a peak period is stored in the PFC unit when the PF value is high, releasing the energy stored in the PFC unit as required when the PF value is underestimated, and further improving the PF value and stably outputting; the PFC capacitor in the PFC unit can be controlled at a lower voltage by matching with the boost-buck circuit and the control circuit, so that the withstand voltage of the PFC capacitor is reduced, and the service life is prolonged; and part of common components or circuits are omitted in design, primary energy conversion is reduced, circuit loss is reduced, and the whole volume of the converter is reduced. The practical value of the invention is greatly improved.

Drawings

Fig. 1 is a schematic diagram of a half-wave symmetric module of a half-wave symmetric converter according to the present invention;

FIG. 2 is a schematic diagram of a half-wave symmetrical output with a buck-boost output in accordance with the present invention;

FIG. 3 is a schematic diagram of a symmetrical two-way isolated output of the present invention;

FIG. 4 is a schematic diagram of a symmetrical non-isolated single output of the present invention;

FIG. 5 is a schematic diagram of a symmetrical buck unipolar converter of the present invention;

FIG. 6 is a schematic diagram of half-wave symmetric commutation combining of a half-wave symmetric converter according to the present invention;

FIG. 7 is a half-wave symmetrical commutation band rectifying architecture of a half-wave symmetrical converter according to the present invention;

FIG. 8 is a half-wave symmetrical converter architecture of a half-wave symmetrical converter according to the present invention;

FIG. 9 is a schematic diagram of a half-wave symmetrical single-pole PFC converter of the present invention;

fig. 10 is a schematic diagram of a simplified half-wave symmetrical single stage PFC converter of the present invention;

FIG. 11 is a schematic diagram of a single stage PFC, half-wave symmetry, multi-path output of the present invention;

FIG. 12 is a schematic diagram of a half-wave symmetric forward converter of a half-wave symmetric converter according to the present invention;

FIG. 13 is a diagram of a half-wave symmetrical conduction waveform of a half-wave symmetrical converter according to the present invention;

FIG. 14 is a waveform illustrating the entire period distribution, parallel valley filling of the present invention;

FIG. 15 is a waveform illustrating energy storage series valley filling according to the present invention;

fig. 16 is a waveform diagram of series-parallel combined valley-fill for a single stage PFC according to the present invention.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

As shown in fig. 1-12, the present invention discloses a half-wave symmetrical converter and a single-pole PFC converter using the half-wave symmetrical converter and combining a PFC unit.

A half-wave symmetric converter, comprising: a first half-wave rectification circuit and a second half-wave rectification circuit, wherein the first half-wave rectification circuit and the second half-wave rectification circuit are composed of any one or two of a diode and a switching tube,

As shown in fig. 1, the first half-wave rectifier circuit is composed of an ac bus input terminal, a diode D1, and a load 1, and the second half-wave rectifier circuit is composed of an ac bus input terminal, a diode D1A, and a load 1A, where the load 1 and the load 1A may be converters, such as a voltage boosting circuit, a voltage reducing circuit, a voltage boosting circuit, a transformer, etc., or may be ordinary belt loads, such as LEDs, resistors, etc.

Specifically, as shown in fig. 2 and 3, the method further includes: the half-wave symmetrical converter comprises a control circuit and a potential energy conversion unit,

the control circuit is formed by combining a switching tube and/or a diode;

it should be noted that, as shown in fig. 2, the control circuit includes a switching tube K1 and a switching tube K1A, and the potential energy conversion unit includes an inductor LP and an inductor LPA; wherein the first loop is: alternating current bus input, diode D1, switch tube K1 and inductance LP, the second loop circuit is: alternating current bus input, switch tube K1A, inductance LPA and diode D1A. The first loop circuit is formed into a buck-boost circuit by adding a diode D7 and a capacitor EC3, and the second loop circuit is formed into a buck-boost circuit by adding a diode D7A and a capacitor EC3A to meet the requirement.

As shown in fig. 3, the first loop is connected to the input terminal of the transformer T1, the second loop is connected to the input terminal of the transformer T1A, and the transformer T1 and the transformer T1A form two-way output.

As shown in fig. 4 and 5, the two output units of the first loop and the second loop are combined into one output circuit according to the requirement, as shown in fig. 5, the PFC unit is composed of a capacitor EC1P, a switching tube K21, and a switching tube K12, and is electrically connected to the second half-wave rectifier circuit, and a voltage reduction circuit is added to the two half-wave rectifier circuits to form a half-wave symmetrical single-circuit output converter

As shown in fig. 13, it is a waveform diagram of the half-wave symmetrical rectifier tube shown in fig. 1-5: the first loop, namely a D1 rectifier tube, is conducted when the sine wave of the input unit is 0-180 degrees; then the second loop, i.e. the D1A rectifier, is conducted when the sine wave of the input unit is 180-. The rectifier tube can be a diode or a switch tube. The full waveform of the input waveform is completely utilized, and only one-time rectification is used, so that twice rectification of bridge rectification is omitted.

As shown in fig. 6, the first loop and the second loop are connected to different windings of the input end of the transformer T1 to form an isolated single-circuit output of phase-change combination, so that the switching control of the first loop and the second loop of the commutation input is transmitted to the converter energy, the voltage phase of the output winding of the converter is the same, and the secondary can provide the phase energy to the output by only once rectification.

The manner in which the commutations are incorporated into the transformer windings to provide in-phase energy to the output may be flyback transferred energy as shown in fig. 6-10, or may be forward transferred energy as shown in fig. 11.

As shown in fig. 7, in order to implement the standard half-wave symmetrical converter of the present invention, the first half-wave rectification circuit is connected to the switching tube K1 and the winding N1 to form a first loop; the second half-wave rectification circuit is connected with the switching tube K1A and the winding N2 to form a second loop circuit; the N3 winding, the D7 and the EC3 are connected to form a third loop; the first loop N1 winding and the second loop N2 winding are combined in the same core transformer T1 in a phase change mode, and the first loop and the second loop are conducted when positive and negative half cycles are input respectively, so that the third loop always keeps the same phase.

As shown in fig. 8, the PFC module is added to the two buses of the input unit, EC1P is charged in the step-up or high-voltage stage, and the valley filling and discharging are performed by turning on KP12 and KP21 in the valley period.

FIG. 9 is a schematic diagram of a half-wave symmetrical single-pole PFC converter according to the present invention; wherein KP12 acts as a parallel valley-fill switch when the first loop is conducting and as a series valley-fill switch during the second loop; KP21 instead acts as a series valley-fill switch when the first loop is conducting and as a parallel valley-fill switch during the second loop, sharing one PFC switch but using two loop main switches K1 and K1A.

As shown in fig. 10, a schematic diagram of the simplified half-wave symmetrical single-stage PFC converter of fig. 9 is shown: the first loop circuit and the second loop circuit share one switch K1, so that one switch K1A is omitted, but when the first loop circuit and the second loop circuit are conducted, the diodes DP and DPA are rectified once more, and the efficiency is reduced.

As shown in fig. 11, an ACF unit is further added, which is a clamping unit, to protect KA1 and C1, and KA1A and C1A, wherein C1 and C1A may also be combined to be a positive terminal connected to ground or PFC capacitor, to absorb the leakage inductance spike energy when demagnetization starts, and to put back the winding for use, so that the switch is turned on at the valley or ZVS zero voltage when the first loop and the second loop are connected. Furthermore, a multi-output module can be added to the secondary stage according to requirements, so that one transformer can realize not only a single-stage PFC function but also a multi-output function.

Specifically, fig. 8-11 also include: the PFC unit is provided with an energy storage capacitor and at least one switching tube, and the position where the PFC unit is placed comprises one or more of the following three types of combinations:

the first method is that the first half-wave rectification circuit and/or the second half-wave rectification circuit are electrically connected (figure 8);

method three, electrically connecting between the windings to ground (fig. 9-11).

FIG. 12 is a schematic diagram of a half-wave symmetric forward converter of the present invention;

as shown in fig. 14-16, a method for controlling a single-pole PFC of a half-wave symmetric converter divides the following nodes by 0 to 360 degrees of a rectified sine wave as one cycle period:

t0, T0 is the lowest valley point of voltage;

t0, T0 is a commutation node of 0 degree, 180 degrees and 360 degrees;

Fig. 14 is a waveform diagram of energy distribution to the PFC unit and the output terminal and valley filling at low voltage in a half-wave symmetric whole period. Fig. 14 is combined with fig. 9, a switch tube KP is a control switch tube inside the PFC unit, a light-colored shaded portion in fig. 14 corresponds to charging of the energy storage capacitor in the PFC unit, and a dark-colored shaded portion corresponds to valley filling and releasing of the PFC unit. The switch tube KP controls the PFC unit to boost or reduce voltage, the switch tube KP12 and the switch tube KP21 control the first half-wave rectification circuit and the second half-wave rectification circuit to control the PFC unit in low voltage, and the PFC unit is connected with the first half-wave rectification circuit or the second half-wave rectification circuit in parallel in a valley filling and releasing process.

Fig. 15 is a waveform diagram of the PFC unit being connected in series with the first half-wave rectifier circuit or the second half-wave rectifier circuit to fill a valley, where IAC at the bottom is a waveform diagram of an output current.

In conjunction with the waveform diagrams shown in fig. 14-16, when the PFC unit is disposed on the input bus, the second loop is turned on for a long time or intermittently to charge the PFC unit in a step up stage of T0-T3, T0-T3A, T1-T3, T1A-T3A, T2-T3, T2A-T3A, or in one of high voltage stages of T2-T4, T2A-T4A.

It should be noted that, as shown in fig. 10 and fig. 15, when the PFC unit is disposed between the winding and the ground, the energy storage charging of the PFC unit during the input sine wave peak time, i.e., T2-T4 and T2A-T4A, is as follows:

Specifically, in the stages of T2-T4 and T2A-T4A, when the voltage of the PFC unit is higher than the input voltage, the PFC unit is led through the first loop or the second loop, the input energy is stored in the potential energy conversion unit, then the first loop or the second loop is closed, the current of the potential energy conversion unit is changed from increasing to decreasing, the windings form back voltage, and then the regulation is performed by any one of the following modes:

the first method is as follows: the PFC unit is conducted, the whole switching period can be stored in the PFC unit or directly transmitted to a secondary, and the processing of a mode one is carried out by adopting one period or repeating more than one period;

It should be noted that in the valley time period, i.e., one of the T5-T1, T5A-T1A and/or T4-T2, T4A-T2A stages, the connection between the PFC unit and the input is any one of parallel connection, series connection and series-parallel combination, and then the input is combined with the input to the potential energy conversion unit to fill the valley output, and the input is transmitted to the output through the potential energy conversion unit, and the waveform diagram of the half-wave symmetrical PFC series-parallel combination filling the valley is described with reference to fig. 16.

It should be noted that, an ACF module and a multi-output module are added as needed, and in the schematic layout, each device may be placed at different positions, for example, D7, DP, LP, T1, K1, KP1, KP2, etc. may be at the positive end or the negative end, or may be combined differently; the further diode can be changed into a switching tube according to the requirement to reduce the loss; the switching tube can be one or a combination of a plurality of MOS tubes, triodes, silicon controlled rectifiers, gallium nitride and the like. Different EMC components and safety components can be added according to the requirements, and components such as diodes, triodes, resistors, capacitors, optocouplers and the like can be added according to the requirements; the switch tube, the VCC starting circuit, the voltage division detection circuit, the current limiting detection circuit and the like can be arranged externally, and can also be integrated into the chip or a combined piece.

In summary, the first half-wave rectification circuit, the second half-wave rectification circuit, the control circuit and the potential energy conversion unit are arranged in the converter, so that the rectification waveform can be obtained by only one rectification tube or synchronous tube in a half rectification period, and isolated output can be realized by one transformer through phase-changing access of two different windings; a PFC unit can be arranged according to the requirement to form a single-stage PFC converter, unnecessary power is reduced by reducing the number of rectifier tubes, the energy conversion efficiency is improved, and the whole volume is reduced; and the control method of the cooperation is as follows: the method comprises the following steps that a single period of a mains supply is divided into a plurality of nodes, the nodes are integrated into a plurality of time periods, a control circuit controls other units and components to work according to the time periods, the processes of rectification, input and output are adjusted, energy is adjusted by matching with a PFC unit, redundant energy in a peak period is stored in the PFC unit when the PF value is high, the energy stored in the PFC unit is released according to needs when the PF value is underestimated, and then the PF value and stable output are improved; the PFC capacitor in the PFC unit can be controlled at a lower voltage by matching with the boost-buck circuit and the control circuit, so that the withstand voltage of the PFC capacitor is reduced, and the service life is prolonged; and part of common components or circuits are omitted in design, primary energy conversion is reduced, circuit loss is reduced, and the whole volume of the converter is reduced. The practical value of the invention is greatly improved.

The above-described examples merely represent one or more embodiments of the present invention, which are described in greater detail and detail, but are not to be construed as limiting the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the spirit of the invention, which falls within the scope of the invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims

1. A half-wave symmetric converter, comprising: the half-wave rectifier circuit comprises a first half-wave rectifier circuit and a second half-wave rectifier circuit, wherein the first half-wave rectifier circuit and the second half-wave rectifier circuit are composed of any one or two of a diode and a switching tube;

2. A half-wave symmetric converter according to claim 1, characterized by comprising: a control circuit and a potential energy conversion unit,

the control circuit is formed by combining a switching tube and/or a diode;

3. A half-wave symmetrical converter according to claim 1, wherein said first half-wave rectifying circuit and said second half-wave rectifying circuit are commutatively connected to different input windings of the same core transformer, alternating the first half cycle and the second half cycle on the corresponding voltage waveform of the input voltage, and the secondary windings form the output voltage of the same phase.

4. A half-wave symmetric converter according to claim 1, further comprising: the PFC unit is provided with an energy storage capacitor and at least one switching tube, and the position where the PFC unit is placed comprises one or more of the following three types of combinations:

5. A control method of a half-wave symmetric converter is characterized in that the following nodes are divided by taking 0 to 180 degrees of a rectified sine wave as a half cycle:

t0, T0 is the lowest valley point of voltage; the phase change nodes are phase change nodes of 0 degree, 180 degrees and 360 degrees;

t0, T0 is a commutation node of 0 degree, 180 degrees and 360 degrees;

T1A, T1A is set in the voltage rising stage, the voltage is greater than T0, and the voltage rising stage is a negative half-cycle low-voltage rising point;

T2A, T2A is set in the voltage rising phase, the voltage is greater than T1A, and the voltage rising phase is a negative half-cycle boosting high-voltage point;

T3A, T3A is a negative half-cycle high voltage point, and the voltage is greater than T2A;

T4A, T4A is set in the voltage reduction phase, the voltage is smaller than the voltage at T3A, and the voltage is a negative half cycle reduction high voltage point;

T5A, T5A is set in the voltage drop stage, the voltage is smaller than the voltage at T4A, and the voltage is a negative half-cycle low-voltage drop point;

6. The method of claim 5, wherein when the PFC unit is disposed on the input bus, the second loop is turned on for a long period or intermittently to charge the PFC unit during one of a boost phase T0-T3, T0-T3A, T1-T3, T1A-T3A, T2-T3, T2A-T3A, or a high voltage phase T2-T4, T2A-T4A.

7. The method of claim 5, wherein the PFC unit is charged during peak input sine wave phases T2-T4 and T2A-T4A when the PFC unit is placed between winding ground in a manner that:

when the voltage of the PFC unit is lower than the input voltage, the control unit controls the input to distribute energy to the PFC unit and the potential energy change unit according to the requirement;

8. The method of claim 5, wherein during the period T2-T4 and T2A-T4A, when the voltage of the PFC unit is higher than the input voltage, the PFC unit is led to pass through the first loop or the second loop, the input energy is stored in the potential energy conversion unit, then the first loop or the second loop is closed, the current of the potential energy conversion unit is changed from increasing to decreasing, the windings form back pressure, and then the voltage is adjusted by any one of the following modes:

9. A control method for a half-wave symmetrical converter as claimed in claim 5, characterized in that in the valley period, i.e. one of the periods T5-T1, T5A-T1A and/or T4-T2, T4A-T2A, said control unit feeds the valley output to the potential energy conversion unit by conducting one or a combination of the first loop, the fourth loop and the fifth loop, and transmits the valley output to the output through said potential energy conversion unit.

10. A method of controlling a half-wave symmetrical converter according to claim 5, comprising: the half-wave rectifier circuit comprises a first half-wave rectifier circuit and a second half-wave rectifier circuit, wherein the first half-wave rectifier circuit and the second half-wave rectifier circuit are composed of any one or two of a diode and a switching tube.

And then two paths of output are combined into a path of in-phase output circuit in a phase-changing manner according to the requirement, and/or different modules such as a single-pole PFC module, an ACF module, a multi-path output module and the like are added according to the requirement to realize different energy supply functions.