阅读说明：本技术 一种非隔离型单相交流稳压电源变换装置及其控制方法 (Non-isolated single-phase alternating current voltage-stabilized power supply conversion device and control method thereof ) 是由 李伦全 周涛 谭魏明 于 2021-05-28 设计创作，主要内容包括：本发明公开了一种非隔离型单相交流稳压电源变换装置及其控制方法,包括双向转换开关单元、输入滤波单元、开关变换单元、输出滤波单元、控制单元。本发明的控制单元根据外部通讯命令或者对外部其他电压、电流信号的判断,可控制双向转换开关单元切换输入输出的端口连接点,同时配合输入输出可以使该交流电路工作于升压、降压或者待机三种工作模式；从而实现所需相对稳定的输出电压,而不受输入电压的波动影响；同时本发明也适用于单相交流电源,三相三线或者三相四线交流电源。(The invention discloses a non-isolated single-phase alternating current voltage-stabilized power supply conversion device and a control method thereof. The control unit can control the bidirectional conversion switch unit to switch the port connection point of the input and the output according to an external communication command or the judgment of other external voltage and current signals, and simultaneously can make the alternating current circuit work in three working modes of boosting, reducing voltage or standby by matching with the input and the output; thereby realizing the required relatively stable output voltage without being influenced by the fluctuation of the input voltage; meanwhile, the invention is also suitable for single-phase alternating current power supplies, three-phase three-wire or three-phase four-wire alternating current power supplies.)

1. A non-isolated single-phase alternating current voltage-stabilized power supply conversion device is characterized in that: the bidirectional conversion circuit comprises a bidirectional conversion switch unit, an input filtering unit, a switch conversion unit, an output filtering unit and a control unit, wherein a first alternating current input end of the bidirectional conversion switch unit is connected with an input alternating current source, a second alternating current output end of the bidirectional conversion switch unit is connected with an output alternating current equivalent load, a first alternating current output end of the bidirectional conversion switch unit is connected with an input end of the input filtering unit, and a second alternating current input end of the bidirectional conversion switch unit is connected with an output end of the output filtering unit; the output end of the input filter unit is connected with the input end of the switch conversion unit, and the input end of the output filter unit is connected with the output end of the switch conversion unit.

2. The non-isolated single-phase alternating current voltage-stabilized power supply conversion device according to claim 1, characterized in that: the control unit comprises an operation processing unit, a signal sampling unit, an auxiliary power supply and a driving unit, and is respectively connected with the input alternating current source, the output alternating current equivalent load, the bidirectional conversion switch unit and the switch conversion unit.

3. The non-isolated single-phase alternating current voltage-stabilized power supply conversion device according to claim 2, characterized in that: the control unit also comprises a communication unit used for communicating with the outside.

4. The non-isolated single-phase alternating current voltage-stabilized power supply conversion device according to claim 1, characterized in that: the bidirectional conversion switch unit comprises a first double-selection switch K1 and a second double-selection switch K2, one ends of the first double-selection switch K1 and the second double-selection switch K2 are connected with the alternating current input end, the other end of the first double-selection switch K1 is connected with the input filtering unit, and the other end of the second double-selection switch K2 is connected with the output filtering unit.

5. The non-isolated single-phase alternating current voltage-stabilized power supply conversion device according to claim 4, characterized in that: the first double-selection switch K1 and the second double-selection switch K2 both adopt switches which can bidirectionally flow current and can be turned off.

6. The non-isolated single-phase alternating current voltage-stabilized power supply conversion device according to claim 1, characterized in that: the switch transformation unit comprises a first capacitor C1, a third switch K3, a fourth switch K4, a first inductor L1 and a second capacitor C2, wherein the first capacitor C1 is connected between a No. 1 port and a No. 3 port of the alternating current input in parallel; one end of the third switch K3 is connected with a No. 1 port of the alternating current input, and the other end of the third switch K3 is respectively connected with one end of the first inductor L1 and one end of the fourth switch K4; the other end of the fourth switch K4 is connected with a No. 3 port of an alternating current input; the other end of the first inductor L1 is connected with a No. 2 port of an alternating current output; the second capacitor C2 is connected in parallel between the No. 2 port and the No. 3 port of the alternating current output.

7. A control method of a non-isolated single-phase ac voltage-stabilized power supply conversion device according to claim 1, comprising the steps of:

(1) the control unit processes the voltage signal or the external communication command;

(2) determining whether the conversion device needs to operate in a standby mode, a boost mode, or a buck mode;

(3) the control unit controls the first switch K1 and the second switch K2 in the bidirectional conversion switch unit to be connected to the high-voltage end or the low-voltage end.

8. The control method of the non-isolated single-phase alternating current voltage-stabilized power supply conversion device according to claim 7, characterized in that: in the step (3), the control unit further applies a control signal to a third switch K3 and a fourth switch K4 of the switch conversion unit, so that the switch conversion unit works in an equivalent boost circuit mode or an equivalent buck circuit mode.

9. The control method of the non-isolated single-phase alternating current voltage-stabilized power supply conversion device according to claim 8, characterized in that: in the step-up or step-down mode, the control unit controls the third switch K3 and the fourth switch K4 of the switch conversion unit to work in a fixed interval of the frequency period of the alternating current voltage, and provides the non-standard sine alternating current voltage, so that the output voltage is compared with the alternating current input voltage to generate step-up or step-down in the working interval.

Technical Field

The invention relates to a switching power supply, in particular to a non-isolated single-phase alternating current stabilized voltage power supply conversion device and a control method thereof.

Background

The power supply grid system all over the world is different nowadays, and has 110VAC power grid, has 220VAC, has 230VAC, even 240VAC etc. simultaneously for various reasons, when the voltage arrives user end or electrical apparatus end, the voltage still can appear just inclining or negative bias, therefore can lead to the power consumption load not to be suitable for. Therefore, when the electric equipment of asian users is brought to europe due to business trip, or a chinese client goes to japan, the united states and the like may need to add a voltage stabilizer, the conventional solution is to design a general power supply, or to configure a large complex voltage stabilizer at the equipment end, when the electric equipment is large, if the power quality requirement on the power grid is not high, the voltage stabilizer may be a conventional low-frequency voltage stabilizer, so that the size is large, and the cost performance is poor in the field with low power; therefore, it is necessary to design a new voltage regulator to meet the needs of users and to have a better cost performance.

Disclosure of Invention

The purpose of the invention is as follows: the invention aims to provide a non-isolated single-phase alternating-current voltage-stabilizing power supply conversion device which can solve the technical problems of complex design, heavy low-frequency non-isolated volume and low cost performance of the conventional alternating-current voltage-stabilizing conversion device; a second object of the present invention is to provide a method for controlling a non-isolated single-phase ac voltage-stabilized power conversion apparatus, which is capable of controlling the conversion apparatus to operate in a standby mode, a boost mode or a buck mode.

The technical scheme is as follows: the invention comprises a non-isolated single-phase alternating current stabilized voltage supply conversion device, which comprises a bidirectional conversion switch unit, an input filtering unit, a switch conversion unit, an output filtering unit and a control unit, wherein a first alternating current input end of the bidirectional conversion switch unit is connected with an input alternating current source, a second alternating current output end of the bidirectional conversion switch unit is connected with an output alternating current equivalent load, a first alternating current output end of the bidirectional conversion switch unit is connected with an input end of the input filtering unit, and a second alternating current input end of the bidirectional conversion switch unit is connected with an output end of the output filtering unit; the output end of the input filter unit is connected with the input end of the switch conversion unit, and the input end of the output filter unit is connected with the output end of the switch conversion unit.

The control unit comprises an operation processing unit, a signal sampling unit, an auxiliary power supply and a driving unit, and is respectively connected with the input alternating current source, the output alternating current equivalent load, the bidirectional conversion switch unit and the switch conversion unit.

The control unit also comprises a communication unit used for communicating with the outside.

The bidirectional conversion switch unit comprises a first double-selection switch K1 and a second double-selection switch K2, one ends of the first double-selection switch K1 and the second double-selection switch K2 are connected with the alternating current input end, the other end of the first double-selection switch K1 is connected with the input filtering unit, and the other end of the second double-selection switch K2 is connected with the output filtering unit.

The first double-selection switch K1 and the second double-selection switch K2 both adopt switches which can bidirectionally flow current and can be turned off.

The switch transformation unit comprises a first capacitor C1, a third switch K3, a fourth switch K4, a first inductor L1 and a second capacitor C2, wherein the first capacitor C1 is connected between a No. 1 port and a No. 3 port of an alternating current input in parallel; one end of the third switch K3 is connected with a No. 1 port of the alternating current input, and the other end of the third switch K3 is respectively connected with one end of the first inductor L1 and one end of the fourth switch K4; the other end of the fourth switch K4 is connected with a No. 3 port of an alternating current input; the other end of the first inductor L1 is connected with a No. 2 port of an alternating current output; the second capacitor C2 is connected in parallel between the No. 2 port and the No. 3 port of the alternating current output.

The invention also comprises a control method of the non-isolated single-phase alternating current stabilized voltage supply conversion device, which comprises the following steps:

(1) the control unit processes the voltage signal or the external communication command;

(2) determining whether the conversion device needs to operate in a standby mode, a boost mode, or a buck mode;

(3) the control unit controls the first switch K1 and the second switch K2 in the bidirectional conversion switch unit to be connected to the high-voltage end or the low-voltage end.

In the step (3), the control unit further applies a control signal to a third switch K3 and a fourth switch K4 of the switch conversion unit, so that the switch conversion unit operates in an equivalent boost circuit mode or an equivalent buck circuit mode.

In the boosting or reducing mode, the control unit controls the third switch K3 and the fourth switch K4 of the switch conversion unit to work in a fixed interval of the frequency period of the alternating-current voltage and provide the non-standard sinusoidal alternating-current voltage, so that the output voltage is boosted or reduced in voltage in the working interval compared with the alternating-current input voltage, and efficiency improvement and energy saving are achieved.

Has the advantages that: compared with the prior art, the invention has the beneficial effects that: (1) the voltage stabilizing circuit is enabled to realize voltage boosting or voltage reduction by controlling the bidirectional conversion switch unit and the switch conversion unit, so that stable voltage is output; (2) when the load can accept non-standard sine alternating-current voltage, the switch conversion unit can work at only part of input interval ends in a frequency cycle, so that high efficiency is realized; (3) the high-frequency work of the switch conversion unit is utilized, so that the change circuit has smaller volume and higher cost performance compared with the traditional power frequency voltage stabilizer.

Drawings

FIG. 1 is a block diagram of the present invention;

FIG. 2 is a circuit diagram of the bidirectional switch unit of FIG. 1;

FIG. 3 is a block diagram of a control unit of FIG. 1;

FIG. 4 is a first schematic diagram of the switch conversion unit shown in FIG. 1;

FIG. 5 is a second schematic diagram of the switch conversion unit shown in FIG. 1;

FIG. 6 is a third schematic diagram of the switch conversion unit shown in FIG. 1;

FIG. 7 is a schematic diagram of switches in the switch conversion unit of FIG. 1;

FIG. 8 is a schematic diagram of the step-down mode operation of the inverter of FIG. 4;

fig. 9 is a schematic diagram of the boost mode operation of the converter of fig. 4.

Detailed Description

The technical scheme of the invention is further described by combining the detailed description and the attached drawings of the specification.

As shown in fig. 1, the present invention includes a bidirectional conversion switch unit, an input filter unit, a switch conversion unit, an output filter unit, and a control unit. The bidirectional change-over switch unit is provided with four interfaces, a first alternating current input end of the bidirectional change-over switch unit is connected with an input alternating current source, a second alternating current output end of the bidirectional change-over switch unit is connected with an output alternating current equivalent load, a first alternating current output end of the bidirectional change-over switch unit is connected with an input end of the input filtering unit, and a second alternating current input end of the bidirectional change-over switch unit is connected with an output end of the output filtering unit; the output end of the input filter unit is connected with the input end of the switch conversion unit, and the input end of the output filter unit is connected with the output end of the switch conversion unit.

As shown in fig. 2, the bidirectional switch unit is connected between the input end and the output end of the AC L line, and includes a first dual-selection switch K1 and a second dual-selection switch K2, one end of the first dual-selection switch K1 and one end of the second dual-selection switch K2 are connected to the AC (alternating current) input end, the other end of the first dual-selection switch K1 is connected to the input filter unit, and the other end of the second dual-selection switch K2 is connected to the output filter unit. Or directly connected with the switch conversion unit, and can have no input filter unit or no output filter unit.

As shown in fig. 3, the control unit includes an arithmetic processing unit, a signal sampling unit, an auxiliary power supply, and a driving unit, which are respectively connected to the input ac source, the output ac equivalent load, the bidirectional switch unit, and the switch conversion unit. Meanwhile, the control unit can also comprise a communication unit which can communicate with the outside.

As shown in fig. 4, the switch converting unit is a single-phase ac switch converting unit, and includes a first capacitor C1, a third switch K3, a fourth switch K4, a first inductor L1, and a second capacitor C2, where the first capacitor C1 is connected in parallel between the No. 1 port and the No. 3 port of the ac input; one end of the third switch K3 is connected with a No. 1 port of the alternating current input, and the other end of the third switch K3 is respectively connected with one end of the first inductor L1 and one end of the fourth switch K4; the other end of the fourth switch K4 is connected with a No. 3 port of an alternating current input; the other end of the first inductor L1 is connected with a No. 2 port of an alternating current output; the second capacitor C2 is connected in parallel between the No. 2 port and the No. 3 port of the alternating current output.

As shown in fig. 7, a-f are possible configurations of the third switch K3 and the fourth switch K4, which are both switches capable of bi-directionally flowing current and turning off, and are semiconductor devices capable of turning on and off by high-frequency electric driving signals, such as MOS transistors or IGBT transistors. The switch tube reverse diode can be an integrated or parasitic diode, and can also be an additional single diode.

The invention also comprises a control method of the non-isolated single-phase alternating current stabilized voltage supply conversion device, which comprises the following steps:

(1) the control unit processes the voltage signal or the external communication command;

(2) determining whether the conversion device needs to operate in a standby mode, a boost mode, or a buck mode;

(3) the control unit controls the first switch K1 and the second switch K2 in the bidirectional conversion switch unit to be connected to the high-voltage end or the low-voltage end.

In the step (3), the control unit further applies a control signal to a third switch K3 and a fourth switch K4 of the switch conversion unit, so that the switch conversion unit works in an equivalent boost circuit mode or an equivalent buck circuit mode. In the step-up or step-down mode, the control unit controls the third switch K3 and the fourth switch K4 of the switch conversion unit to operate in a fixed interval of the frequency period of the alternating voltage, and provides the non-standard sinusoidal alternating voltage, so that the output voltage is compared with the alternating input voltage to generate step-up or step-down in the operation interval.

The control method is further described below by taking the circuit of the first embodiment as an example:

the control unit is operated by a program in the operation processor unit through a voltage signal sampled by the sampling circuit or a command obtained by external communication, and when the circuit is judged to need to work in a boosting mode, the control unit controls a first double-selection switch K1 in the bidirectional conversion switch to be connected to a port 1 and controls a second double-selection switch K2 to be connected to a port 2; meanwhile, a control signal is applied to the third switch K3 and the fourth switch K4 of the switching conversion unit, so that the switching conversion unit operates in an equivalent boost circuit mode (boost). When the judging circuit works in a voltage reduction mode, a first double-selection switch K1 in the bidirectional transfer switch is controlled to be connected to the 2 port, and a second double-selection switch K2 is controlled to be connected to the 1 port; meanwhile, a control signal is applied to the third switch K3 and the fourth switch K4 of the switching conversion unit, so that the switching conversion unit works in an equivalent buck circuit mode (buck). When the circuit works in a standby mode, a first double-selection switch K1 and a second double-selection switch K2 in the pair of control bidirectional switches are respectively connected to the port 1 and the port 2, and the switching of a boosting mode or a voltage reduction mode is waited.

As shown in fig. 8, assuming that it has been determined that the converter needs to operate in the buck mode, the bidirectional switch has been switched to the corresponding position, or the external conditions (ac input and ac output conditions) of the switch conversion unit have been set manually (or artificially), therefore, after the operation of the operation processor of the controller unit, the high-frequency PWM driving signal is sent out to drive the third switch K3 and the fourth switch K4 in the switch conversion unit through the driving unit, and assuming that the ac is a positive half-wave as in a diagram in fig. 8, when K3 is first turned on, the ac passes through K3 and the first inductor L1 to reach the output load end, and the part where the input voltage is higher than the output voltage stores energy in L1, and when K3 is turned off and K4 is turned on as in b diagram in fig. 8, the stored energy in L1 will continue to be released. On the contrary, when the voltage is negative half wave, the current is reversed, corresponding to the graphs c and d of fig. 8. And then the control and the operation are carried out repeatedly according to the working frequency of the voltage. The working effect of the control method is consistent with that of a Buck circuit which is well known, so that the in-phase step-down conversion of the alternating-current input voltage is realized.

As shown in fig. 9, assuming that it has been determined that the converter needs to operate in the boost mode, the bidirectional switch has been switched to the corresponding position, or the external conditions (ac input and ac output conditions) of the switch conversion unit have been set manually (or artificially), therefore, after the operation of the operation processor of the controller unit, a high-frequency PWM driving signal is sent to drive the third switch K3 and the fourth switch K4 in the switch conversion unit through the driving unit, and assuming that the ac is a positive half-wave as shown in a of fig. 9, when K4 is first turned on, the ac is applied to both ends of the first inductor L1 through K4, so that L1 stores energy, and when K4 is turned off and K3 is turned on as shown in b of fig. 9, the stored energy originally in L1 is released to be superimposed with the ac. Conversely, when the voltage is negative half wave, the current is reversed, corresponding to graphs c and d of fig. 9. And then the control and the operation are carried out repeatedly according to the working frequency of the voltage. The working effect of the control method is consistent with that of a well-known Boost circuit, so that in-phase Boost conversion of the alternating-current input voltage is realized.

In addition, in the boost or buck mode, the third switch K3 and the fourth switch K4 of the switching conversion unit are controlled to operate only in a certain section of the frequency cycle of the alternating-current voltage, so that a non-standard sinusoidal alternating-current voltage is provided, and the output voltage is boosted or stepped down only in the operating section compared with the alternating-current input voltage, thereby improving efficiency and saving energy.

Therefore, no matter in a boosting mode or a voltage reduction mode, or partial boosting or voltage reduction, the mode switching of the circuit for realizing the boosting and voltage reduction is realized by utilizing the bidirectional converter, and the switching belongs to the switching of low frequency, so that the circuit is simple; meanwhile, the in-phase voltage boosting and reducing are realized by utilizing the high-frequency work of the switch conversion device, so that a power frequency transformer or self-coupling conversion in the traditional voltage stabilizer is separated, the circuit is small in size, high in density and good in cost performance.

As shown in fig. 5 and fig. 6, which are other embodiments of the first embodiment, as shown in fig. 5, the three single-phase converters shown in fig. 4 are connected to a three-phase four-wire ac source respectively for operation, which is substantially the three single-phase converters with different phases of ac voltage, and the specific operation principle of the single-phase converters is consistent with that of the single phase, so as to meet the voltage stabilization operation requirement of the three-phase four-wire ac system. And meanwhile, the N line is also suspended and is not connected with the input end. As shown in fig. 6, the single-phase ac conversion device may be connected to any two of the three phases that do not overlap, so that the three converters may be connected to the three-phase ac source, respectively. That is, it can be seen that the ac voltage of the single-phase converter is changed from L line and N line to LaLb, LbLc, or LcLa, which have different phases, and the specific operation principle of the single-phase converter is also consistent with that of the single phase. Therefore, the specific operation principle analysis of fig. 5 and 6 is not described one by one.