阅读说明：本技术 一种基于两相三桥臂逆变电路的控制方法及系统 (Control method and system based on two-phase three-bridge-arm inverter circuit ) 是由 胡建明 廖春富 朱佳军 于 2020-03-25 设计创作，主要内容包括：本发明公开了一种基于两相三桥臂逆变电路的控制方法及系统,所述控制方法包括：检测所述两相三桥臂逆变电路输出侧的当前输出电压,将所述当前输出电压与设定的参考电压进行差运算,以获取偏移差值；利用比例积分控制器基于所述偏移差值对当前调制波信号进行调整；将调整后的调制波信号与设定的载波信号进行比较,产生所述两相三桥臂逆变电路中的每一个桥臂所对应的一组启闭互补PWM信号；基于每一组启闭互补PWM信号控制所述两相三桥臂逆变电路中对应的一个桥臂的工作状态,以输出最终的电压波形。所述控制方法简单,采用简单的控制器即可实现控制效果,适用于成本要求高且控制精度要求较低的场合,如电梯后备电源。(The invention discloses a control method and a system based on a two-phase three-bridge-arm inverter circuit, wherein the control method comprises the following steps: detecting the current output voltage of the output side of the two-phase three-bridge-arm inverter circuit, and performing difference operation on the current output voltage and a set reference voltage to obtain an offset difference value; adjusting the current modulation wave signal based on the offset difference value by using a proportional-integral controller; comparing the adjusted modulation wave signal with a set carrier signal to generate a group of on-off complementary PWM signals corresponding to each bridge arm in the two-phase three-bridge arm inverter circuit; and controlling the working state of a corresponding bridge arm in the two-phase three-bridge arm inverter circuit based on each set of on-off complementary PWM signals so as to output a final voltage waveform. The control method is simple, the control effect can be realized by adopting a simple controller, and the control method is suitable for occasions with high cost requirements and low control precision requirements, such as an elevator backup power supply.)

1. A control method based on a two-phase three-bridge arm inverter circuit is characterized by comprising the following steps:

detecting the current output voltage of the output side of the two-phase three-bridge-arm inverter circuit, and performing difference operation on the current output voltage and a set reference voltage to obtain an offset difference value;

adjusting the current modulation wave signal based on the offset difference value by using a proportional-integral controller;

comparing the adjusted modulation wave signal with a set carrier signal to generate a group of on-off complementary PWM signals corresponding to each bridge arm in the two-phase three-bridge arm inverter circuit;

and controlling the working state of a corresponding bridge arm in the two-phase three-bridge arm inverter circuit based on each set of on-off complementary PWM signals so as to output a final voltage waveform.

2. The control method according to claim 1, wherein the detecting a current output voltage at an output side of the two-phase three-bridge inverter circuit, and performing a difference operation on the current output voltage and a set reference voltage to obtain an offset difference value comprises:

detecting a first output voltage U between a first phase voltage output end and a zero line output end of the output side of the two-phase three-bridge arm inverter circuit_ANThrough said first output voltage U_ANSubtracting the set reference voltage U to obtain a first offset difference value;

detecting a second output voltage U between a second phase voltage output end of the output side of the two-phase three-bridge arm inverter circuit and a zero line output end_BNThrough said second output voltage U_BNSubtracting the set reference voltage U to obtain a second offset difference value;

based on the first output voltage U_ANAnd the second output voltage U_BNObtaining a third output voltage U between a first phase voltage output end and a second phase voltage output end of the two-phase three-bridge arm output side_ABAnd through the third output voltage U_ABAnd a set reference voltageAnd subtracting to obtain a third offset.

3. The control method according to claim 2, wherein the adjusting the current modulation wave signal based on the offset difference value by using a proportional-integral controller comprises:

based on the first offset difference, the amplitude U of the first modulated wave S1 is adjusted by a first proportional integral controller₁Is adjusted to be U'₁And the first modulated wave S1 obtained by the first multiplier at time T is:

S1＝U′₁sin(ωt)

based on the second offset difference, the amplitude U of the second modulated wave S2 is adjusted by a second proportional-integral controller₂Is adjusted to be U'₂(ii) a Adjusting a phase difference Δ θ of the second modulated wave S2 to Δ θ' with a third proportional-integral controller based on the third offset amount; combined pipeThe second modulation wave S2 obtained by the phase shifter and the second multiplier at time T is:

wherein sin (ω t) is a unit sine signal, ω is a frequency, t is a time, U'₁Is the amplitude, U 'of first modulated wave S1 at the time T'₂Δ θ' is the phase difference of the second modulated wave S2 at the time T, and T ∈ T, which is the amplitude of the second modulated wave S2 at the time T.

4. The control method according to claim 3, wherein the comparing the adjusted modulated wave signal with a set carrier signal to generate a set of on-off complementary PWM signals corresponding to each bridge arm of the two-phase three-bridge arm inverter circuit comprises:

the first modulation wave S1 at the time T is compared with the carrier signal in a superposition mode, and a first group of on-off complementary PWM signals corresponding to a first bridge arm in the two-phase three-bridge-arm inverter circuit are generated according to a matching jump principle;

the second modulation wave S2 at the time T is compared with the carrier signal in a superposition mode, and a second group of on-off complementary PWM signals corresponding to a second bridge arm in the two-phase three-bridge-arm inverter circuit are generated according to a matching jump principle;

and performing superposition comparison on the third modulation wave S3 and the carrier signal, and generating a third group of on-off complementary PWM signals corresponding to a third bridge arm in the two-phase three-bridge-arm inverter circuit according to a matching and hopping principle.

5. The control method according to claim 4, wherein the third modulated wave S3 is:

wherein M is the amplitude of the carrier signal, and the carrier signal is a triangular carrier.

6. The control method according to claim 5, wherein the controlling the operating state of a corresponding one of the two-phase three-leg inverter circuits based on each set of on-off complementary PWM signals to output a final voltage waveform comprises:

controlling the interactive on-off of a first switch tube and a second switch tube on the first bridge arm based on the first group of on-off complementary PWM signals;

controlling the interactive on-off of a third switching tube and a fourth switching tube on the second bridge arm based on the second group of on-off complementary PWM signals;

and controlling the interactive on-off of a fifth switching tube and a sixth switching tube on the third bridge arm based on the third group of on-off complementary PWM signals.

7. A control system based on two-phase three-bridge arm inverter circuit is characterized by comprising:

the voltage detection module is used for detecting the current output voltage at the output side of the two-phase three-bridge-arm inverter circuit and carrying out difference operation on the current output voltage and a set reference voltage so as to obtain an offset difference value;

the waveform adjusting module is used for adjusting the current modulating wave signal based on the offset difference value by utilizing a proportional-integral controller;

the signal generation module is used for comparing the adjusted modulation wave signal with a set carrier signal and generating a group of on-off complementary PWM signals corresponding to each bridge arm in the two-phase three-bridge arm inverter circuit;

and the state control module is used for controlling the working state of a corresponding bridge arm in the two-phase three-bridge arm inverter circuit based on each group of on-off complementary PWM signals so as to output a final voltage waveform.

8. The control system of claim 7, wherein the voltage detection module comprises a first voltage detection circuit and a second voltage detection circuit;

the first voltage detection circuit is used for detecting a first output voltage U between a first phase voltage output end and a zero line output end of the output side of the two-phase three-bridge-arm inverter circuit_ANThrough said first output voltage U_ANSubtracting the set reference voltage U to obtain a first offset difference value;

the second voltage detection circuit is used for detecting a second output voltage U between a second phase voltage output end and a zero line output end of the output side of the two-phase three-bridge-arm inverter circuit_BNThrough said second output voltage U_BNSubtracting the set reference voltage U to obtain a second offset difference value; and based on the first output voltage U_ANAnd the second output voltage U_BNObtaining a third output voltage U between a first phase voltage output end and a second phase voltage output end of the two-phase three-bridge arm output side_ABAnd through the third output voltage U_ABAnd a set reference voltageAnd subtracting to obtain a third offset.

9. The control system of claim 8, wherein the waveform adjustment module includes a first proportional-integral controller, a second proportional-integral controller, and a third proportional-integral controller;

the first proportional integral controller is used for regulating the amplitude U of the first modulated wave S1 based on the first offset difference₁Is adjusted to be U'₁And the first modulated wave S1 obtained by the first multiplier at time T is:

S1＝U′₁sin(ωt)

the second proportional integral controller is used for regulating the amplitude U of the second modulation wave S2 based on the second offset difference₂Is adjusted to be U'₂；

The third proportional-integral controller is configured to adjust the phase difference Δ θ of the second modulated wave S2 to Δ θ' based on the third offset amount, and obtain, through the phase shifter and the second multiplier, the second modulated wave S2 at time T as:

wherein sin (ω t) is a unit sine signal, ω is a frequency, t is a time, U'₁Is the amplitude, U 'of first modulated wave S1 at the time T'₂Δ θ' is the phase difference of the second modulated wave S2 at the time T, and T ∈ T, which is the amplitude of the second modulated wave S2 at the time T.

10. The control system of claim 9, wherein the signal generation module comprises a first PWM generation circuit, a second PWM generation circuit, and a third PWM generation circuit;

the first PWM generating circuit is used for performing superposition comparison on the first modulation wave S1 at the time T and the carrier signal, and generating a first group of on-off complementary PWM signals corresponding to a first bridge arm in the two-phase three-bridge-arm inverter circuit according to a matching and jumping principle;

the second PWM generating circuit is configured to compare the second modulation wave S2 at the time T with the carrier signal in a superposition manner, and generate a second set of on-off complementary PWM signals corresponding to a second bridge arm in the two-phase three-bridge inverter circuit according to a matching and hopping principle;

the third PWM generating circuit is configured to perform superposition comparison on a third modulated wave S3 and the carrier signal, and generate a third set of on-off complementary PWM signals corresponding to a third bridge arm in the two-phase three-bridge inverter circuit according to a matching and hopping principle, where the third modulated wave S3 is:

wherein M is the amplitude of the carrier signal, and the carrier signal is a triangular carrier.

Technical Field

The invention relates to the technical field of inverter control, in particular to a control method and a control system based on a two-phase three-bridge-arm inverter circuit.

Background

An inverter is a power electronic device that converts direct current into alternating current, and is applied to various power systems. The current power utilization voltage grades required by various power utilization equipment can be divided into 220V and 380V, most of the power utilization equipment only needs one power utilization voltage, and a small part of the power utilization equipment simultaneously needs the two power utilization voltages, such as an elevator system.

Disclosure of Invention

The invention aims to overcome the defects of the prior art, and provides a control method and a control system based on a two-phase three-bridge-arm inverter circuit.

Correspondingly, the embodiment of the invention provides a control method based on a two-phase three-bridge-arm inverter circuit, which comprises the following steps:

detecting the current output voltage of the output side of the two-phase three-bridge-arm inverter circuit, and performing difference operation on the current output voltage and a set reference voltage to obtain an offset difference value;

adjusting the current modulation wave signal based on the offset difference value by using a proportional-integral controller;

comparing the adjusted modulation wave signal with a set carrier signal to generate a group of on-off complementary PWM signals corresponding to each bridge arm in the two-phase three-bridge arm inverter circuit;

and controlling the working state of a corresponding bridge arm in the two-phase three-bridge arm inverter circuit based on each set of on-off complementary PWM signals so as to output a final voltage waveform.

Optionally, the detecting a current output voltage at an output side of the two-phase three-bridge arm inverter circuit, and performing a difference operation on the current output voltage and a set reference voltage to obtain an offset difference value includes:

detecting a first output voltage U between a first phase voltage output end and a zero line output end of the output side of the two-phase three-bridge arm inverter circuit_ANThrough said first output voltage U_ANSubtracting the set reference voltage U to obtain a first offset difference value;

detecting a second output voltage U between a second phase voltage output end of the output side of the two-phase three-bridge arm inverter circuit and a zero line output end_BNThrough said second output voltage U_BNSubtracting the set reference voltage U to obtain a second offset difference value;

based on the first output voltage U_ANAnd the second output voltage U_BNObtaining a third output voltage U between a first phase voltage output end and a second phase voltage output end of the two-phase three-bridge arm output side_ABAnd through the third output voltage U_ABAnd a set reference voltageAnd subtracting to obtain a third offset.

Optionally, the adjusting, by the proportional-integral controller, the current modulation wave signal based on the offset difference includes:

based on the first offset difference, the amplitude U of the first modulated wave S1 is adjusted by a first proportional integral controller₁Is adjusted to be U'₁And the first modulated wave S1 obtained by the first multiplier at time T is:

S1＝U′₁sin₍ωt)

based on the second offset difference, the amplitude U of the second modulated wave S2 is adjusted by a second proportional-integral controller₂Is adjusted to be U'₂(ii) a Adjusting a phase difference Δ θ of the second modulated wave S2 to Δ θ' with a third proportional-integral controller based on the third offset amount; and obtaining a second modulated wave S2 at time T by the phase shifter and the second multiplier as:

wherein sin (ω t) is a unit sine signal, ω is a frequency, t is a time, U'₁Is the amplitude, U 'of first modulated wave S1 at the time T'₂Δ θ' is the phase difference of the second modulated wave S2 at the time T, and T ∈ T, which is the amplitude of the second modulated wave S2 at the time T.

Optionally, the comparing the adjusted modulation wave signal with a set carrier signal to generate a set of on-off complementary PWM signals corresponding to each bridge arm in the two-phase three-bridge arm inverter circuit includes:

the first modulation wave S1 at the time T is compared with the carrier signal in a superposition mode, and a first group of on-off complementary PWM signals corresponding to a first bridge arm in the two-phase three-bridge-arm inverter circuit are generated according to a matching jump principle;

the second modulation wave S2 at the time T is compared with the carrier signal in a superposition mode, and a second group of on-off complementary PWM signals corresponding to a second bridge arm in the two-phase three-bridge-arm inverter circuit are generated according to a matching jump principle;

and performing superposition comparison on the third modulation wave S3 and the carrier signal, and generating a third group of on-off complementary PWM signals corresponding to a third bridge arm in the two-phase three-bridge-arm inverter circuit according to a matching and hopping principle.

Optionally, the third modulated wave S3 is:

wherein M is the amplitude of the carrier signal, and the carrier signal is a triangular carrier.

Optionally, the controlling the working state of a corresponding one of the two-phase three-leg inverter circuits based on each set of on-off complementary PWM signals to output a final voltage waveform includes:

controlling the interactive on-off of a first switch tube and a second switch tube on the first bridge arm based on the first group of on-off complementary PWM signals;

controlling the interactive on-off of a third switching tube and a fourth switching tube on the second bridge arm based on the second group of on-off complementary PWM signals;

and controlling the interactive on-off of a fifth switching tube and a sixth switching tube on the third bridge arm based on the third group of on-off complementary PWM signals.

In addition, an embodiment of the present invention further provides a control system based on a two-phase three-bridge-arm inverter circuit, where the control system includes:

the voltage detection module is used for detecting the current output voltage at the output side of the two-phase three-bridge-arm inverter circuit and carrying out difference operation on the current output voltage and a set reference voltage so as to obtain an offset difference value;

the waveform adjusting module is used for adjusting the current modulating wave signal based on the offset difference value by utilizing a proportional-integral controller;

the signal generation module is used for comparing the adjusted modulation wave signal with a set carrier signal and generating a group of on-off complementary PWM signals corresponding to each bridge arm in the two-phase three-bridge arm inverter circuit;

and the state control module is used for controlling the working state of a corresponding bridge arm in the two-phase three-bridge arm inverter circuit based on each group of on-off complementary PWM signals so as to output a final voltage waveform.

Optionally, the voltage detection module includes a first voltage detection circuit and a second voltage detection circuit;

the first voltage detection circuit is used for detecting a first output voltage U between a first phase voltage output end and a zero line output end of the output side of the two-phase three-bridge-arm inverter circuit_ANThrough said first output voltage U_ANWith a set reference voltage U phaseSubtracting to obtain a first offset difference value;

the second voltage detection circuit is used for detecting a second output voltage U between a second phase voltage output end and a zero line output end of the output side of the two-phase three-bridge-arm inverter circuit_BNThrough said second output voltage U_BNSubtracting the set reference voltage U to obtain a second offset difference value; and based on the first output voltage U_ANAnd the second output voltage U_BNObtaining a third output voltage U between a first phase voltage output end and a second phase voltage output end of the two-phase three-bridge arm output side_ABAnd through the third output voltage U_ABAnd a set reference voltageAnd subtracting to obtain a third offset.

Optionally, the waveform adjusting module includes a first proportional-integral controller, a second proportional-integral controller, and a third proportional-integral controller;

the first proportional integral controller is used for regulating the amplitude U of the first modulated wave S1 based on the first offset difference₁Is adjusted to be U'₁And the first modulated wave S1 obtained by the first multiplier at time T is:

S1＝U′₁sin(ωt)

the second proportional integral controller is used for regulating the amplitude U of the second modulation wave S2 based on the second offset difference₂Is adjusted to be U'₂；

The third proportional-integral controller is configured to adjust the phase difference Δ θ of the second modulated wave S2 to Δ θ' based on the third offset amount, and obtain, through the phase shifter and the second multiplier, the second modulated wave S2 at time T as:

wherein sin (ω t) is a unit sine signal, ω is a frequency, t is a time, U'₁Is the amplitude, U 'of first modulated wave S1 at the time T'₂Δ θ' is the phase difference of the second modulated wave S2 at the time T, and T ∈ T, which is the amplitude of the second modulated wave S2 at the time T.

Optionally, the signal generating module includes a first PWM generating circuit, a second PWM generating circuit, and a third PWM generating circuit;

the first PWM generating circuit is used for performing superposition comparison on the first modulation wave S1 at the time T and the carrier signal, and generating a first group of on-off complementary PWM signals corresponding to a first bridge arm in the two-phase three-bridge-arm inverter circuit according to a matching and jumping principle;

the second PWM generating circuit is configured to compare the second modulation wave S2 at the time T with the carrier signal in a superposition manner, and generate a second set of on-off complementary PWM signals corresponding to a second bridge arm in the two-phase three-bridge inverter circuit according to a matching and hopping principle;

the third PWM generating circuit is configured to perform superposition comparison on a third modulated wave S3 and the carrier signal, and generate a third set of on-off complementary PWM signals corresponding to a third bridge arm in the two-phase three-bridge inverter circuit according to a matching and hopping principle, where the third modulated wave S3 is:

wherein M is the amplitude of the carrier signal, and the carrier signal is a triangular carrier.

In the embodiment of the invention, based on the current output voltage of the two-phase three-bridge arm inverter circuit, the switching time of each switching tube in the two-phase three-bridge arm inverter circuit is adjusted by adopting a PWM control technology, so that the required sinusoidal alternating-current voltage is generated at the output side of the two-phase three-bridge arm inverter circuit. Compared with a three-phase four-bridge arm inverter in the prior art, the control method provided by the invention is simpler, coordinate system transformation and current sampling are not needed, and the cost of a control system can be greatly reduced, so that the total cost of a corresponding two-phase three-bridge arm inverter product is effectively reduced.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic diagram of a two-phase three-leg inverter circuit according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a two-phase three-bridge arm inverter circuit disclosed in the embodiment of the present invention;

fig. 3 is a schematic flow chart of a control method based on a two-phase three-bridge-arm inverter circuit according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of a forming process of a PWM control signal of a first bridge arm according to the embodiment of the invention;

fig. 5 is a schematic structural composition diagram of a control system based on a two-phase three-bridge inverter circuit according to an embodiment of the present invention;

fig. 6 is a schematic diagram of a specific implementation process of a control system based on a two-phase three-bridge inverter circuit according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1 to 2, fig. 1 is a schematic diagram of a two-phase three-leg inverter circuit according to an embodiment of the present invention, and fig. 2 is a schematic diagram of a structure of the two-phase three-leg inverter circuit according to the embodiment of the present invention.

As shown in fig. 1, a two-phase three-bridge arm inverter circuit includes a dc power supply 100, an energy storage unit, an inverter control unit, and a filtering unit; the dc power supply 100 is connected to the energy storage unit, and the energy storage unit is connected to the inverter control unit.

Specifically, the inversion control unit comprises a first bridge arm, a second bridge arm and a third bridge arm which are arranged in parallel, the filtering unit comprises a first L C filter, a second L C filter and a first filtering inductor, the input end of the first L C filter is connected with the output end a of the first bridge arm, the output end of the first L C filter is connected with a first phase voltage output end A, the input end of the second L C filter is connected with the output end B of the second bridge arm, the output end of the second L C filter is connected with a second phase voltage output end B, one end of the first filtering inductor is connected with the output end N1 of the third bridge arm, and the other end of the first filtering inductor is connected with a zero line output end N.

Further, as shown in fig. 2, the energy storage unit includes a first bus capacitor DC1 and a second bus capacitor DC2 that are serially connected, one end of the first bus capacitor DC1 is connected to the positive electrode of the DC power supply 100, one end of the second bus capacitor DC2 is connected to the negative electrode of the DC power supply 100, and the zero line output terminal N is led out from a connection conductor between the first bus capacitor DC1 and the second bus capacitor DC 2.

Further, as shown in fig. 2, a first switching tube Q1 and a second switching tube Q2 are connected in series in the first arm, and an emitter of the first switching tube Q1 is connected to a collector of the second switching tube Q2; a third switching tube Q3 and a fourth switching tube Q4 are sequentially connected in series on the second bridge arm, and an emitter of the third switching tube Q3 is connected with a collector of the fourth switching tube Q4; a fifth switching tube Q5 and a sixth switching tube Q6 are connected in series in sequence on the third arm, and an emitter of the fifth switching tube Q5 is connected with a collector of the sixth switching tube Q6.

The collector of the first switching tube Q1, the collector of the third switching tube Q3 and the collector of the fifth switching tube Q5 are respectively connected with one end of the first bus capacitor DC 1; the emitter of the second switch tube Q2, the emitter of the fourth switch tube Q4 and the emitter of the sixth switch tube Q6 are respectively connected with one end of the second bus capacitor DC 2.

Further, as shown in fig. 2, the first L C filter includes a second filter inductor L and a first filter capacitor C1, a first end of the second filter inductor L is connected to the connection conductor between the first switching tube Q1 and the second switching tube Q2, a second end of the second filter inductor L11 is connected to the first phase voltage output terminal a, a first end of the first filter capacitor C1 is connected to a second end of the second filter inductor L1, a second end of the first filter capacitor C1 is connected to the neutral line output terminal N, the second L C filter includes a third filter inductor L and a second filter capacitor C2, a first end of the third filter inductor 5 is connected to the connection conductor between the third switching tube Q3 and the fourth switching tube Q4, a second end of the third filter inductor L is connected to the second phase voltage output terminal B, a first end of the second filter capacitor C5 is connected to the connection conductor between the second switching tube Q3 and the fourth switching tube Q4, a second end of the third filter inductor C L is connected to the second filter inductor 633, and a fifth end of the filter inductor 8427N is connected to the neutral line 863, and the second end of the second filter inductor 8427N.

Based on the two-phase three-bridge arm inverter circuit provided in fig. 2, fig. 3 shows a schematic flow chart of a control method based on the two-phase three-bridge arm inverter circuit in the embodiment of the present invention.

As shown in fig. 3, a control method based on a two-phase three-bridge arm inverter circuit includes the following steps:

s101, detecting the current output voltage of the output side of the two-phase three-bridge arm inverter circuit, and performing difference operation on the current output voltage and a set reference voltage to obtain an offset difference value;

it should be noted that, because three bridge arms in the two-phase three-bridge-arm inverter circuit are controlled by an external controller, and when the two-phase three-bridge-arm inverter circuit initially works, the external controller already forms PWM control signals for the three bridge arms, the control method provided in the embodiment of the present invention reversely adjusts the PWM control signals of the three bridge arms by using the current output voltage at the output side of the two-phase three-bridge-arm inverter circuit, so as to achieve the purpose of outputting the required sinusoidal ac voltage.