阅读说明：本技术 电源转换控制方法、系统和计算机可读存储介质 (Power conversion control method, system and computer readable storage medium ) 是由 张明 俞志杰 李翔宇 于 2020-04-16 设计创作，主要内容包括：本发明涉及一种电源转换控制方法、系统和计算机可读存储介质,本发明采集输入线电压,并将线电压转换为相电压,确定相电压所属的电压区间,将相电压变换到平面坐标系的电压值,对平面坐标系的电压值和所属的电压区间,使用空间矢量法计算得到电压矢量输出时间比之后,只需要设定相关寄存器即可输出目标PWM脉冲,控制并驱动矩阵变换开关模块进行电源转换,减少硬件成本、减小体积、降低系统软件开发难度。(The invention relates to a power supply conversion control method, a system and a computer readable storage medium, wherein the method comprises the steps of collecting input line voltage, converting the line voltage into phase voltage, determining a voltage interval to which the phase voltage belongs, converting the phase voltage into a voltage value of a plane coordinate system, calculating the voltage value of the plane coordinate system and the voltage interval to which the phase voltage belongs by using a space vector method, outputting a target PWM pulse only by setting a relevant register, controlling and driving a matrix conversion switch module to perform power supply conversion, and reducing hardware cost, volume and system software development difficulty.)

1. A power supply conversion control method is characterized in that,

collecting line voltage (V) of three-phase AC input_RS、V_ST、V_TR)；

Inputting the three-phase AC input line voltage (V)_RS、V_ST、V_TR) Converted into a phase voltage (V)_R、V_S、V_T)；

According to the phase voltage (V)_R、V_S、V_T) Determining a voltage interval to which the phase voltage belongs;

carrying out three-phase voltage-two-phase voltage conversion on the phase voltage to obtain a voltage value (V) of a plane coordinate system_α、V_β)；

According to V_α、V_βAnd the affiliated voltage interval, and the output time ratio T of two non-zero vector voltages in the affiliated voltage interval is calculated by using a space vector method₁、T₂And a zero vector voltage output time ratio T_z；

Setting a PWM register in the controller according to a preset switch output mode and the output time ratio;

and the controller outputs PWM pulses according to the PWM register, controls and drives the matrix transformation switch module to act, and outputs the conversion voltage.

2. The power conversion control method according to claim 1, wherein the voltage interval includes six:

a first interval: v_R≥V_S≥V_T；

A second interval: v_S>V_R≥V_T；

The third interval: v_S≥V_T>V_R；

A fourth interval: v_T>V_S>V_R；

The fifth interval: v_T>V_R≥V_S；

A sixth interval: v_R≥V_T>V_S。

3. The power supply changeover control method according to claim 1, wherein the voltage value (V) to the planar coordinate system_α、V_β) Corrected voltage value (V)_α+、V_β+) For the corrected voltage value (V)_α+、V_β+) And the affiliated voltage interval, and the output time ratio T is calculated by using a space vector method₁、T₂、T_z。

4. The power conversion control method according to claim 3, wherein the correction method is: will V_α、V_βConversion to unit vector representation:

duty correction is carried out on the unit vector value:

the duty is a correction coefficient.

5. The power supply changeover control method according to claim 1 or 3, wherein the output time ratio T is₁、T₂、T_zThe calculation method comprises the following steps:

voltage value (V) of the plane coordinate system_α、V_β) Or corrected voltage value (V)_α+、V_β+) The space basic vector voltages in the voltage range are Vx and Vy, and the action time of the space basic vector voltages is T₁、T₂；

The component of Vx on α axis is V_1αThe component on the β axis being V_1β；

The component of Vy on the α axis is V_2αThe component on the β axis being V_2β；

T_z＝(1-(T₁+T₂))/2。

6. The power supply changeover control method according to claim 5,

first interval (V)₁、V₂)：V_1α＝1；V_1β＝0；

Second interval (V)₂、V₃)：

Third interval (V)₃、V₄)：V_2α＝-1；V_2β＝0；

Fourth interval (V)₄、V5₎：V_1α＝-1；V_1β＝0；

Fifth interval (V)₅、V₆₎：

Sixth interval (V)₆、V₁)：V_2α＝1；V_2β＝0。

7. The power conversion control method according to any one of claims 1 to 6, wherein a commutation register is set simultaneously with setting a PWM register in the controller, and the controller outputs PWM pulses according to the PWM register and the commutation register.

8. A power conversion control system, the control system comprising:

a matrix transformation switch module: for outputting a target voltage;

a control module for controlling the matrix-commutated switch module according to the method of any one of claims 1-7.

9. A computer-readable storage medium storing a computer program for use in conjunction with a matrix switch module, the computer program being executable by a processor to implement the method of any one of claims 1-7.

Technical Field

The present invention relates to the field of power conversion control technologies, and in particular, to a power conversion control method, system, and computer-readable storage medium.

Background

The direct-current power supply conversion system in the existing market generally adopts traditional frequency conversion control, AC-DC-AC → rectification, and uses an electrolytic capacitor as a part of an intermediate energy storage link, and the electrolytic capacitor has large volume and short service life, so that the whole system has large volume and short service life, and the development difficulty of control system software is also large.

Disclosure of Invention

The invention aims to provide a power supply conversion control method and a power supply conversion control system, which cancel an intermediate energy storage link and solve the problems of large volume, high cost and large development difficulty of the traditional frequency conversion control scheme in an AC-AC + rectification mode.

In order to achieve the technical purpose, the invention provides a power supply conversion control method, which comprises the following steps:

collecting line voltage (V) of three-phase AC input_RS、V_ST、V_TR)；

Inputting the three-phase AC input line voltage (V)_RS、V_ST、V_TR) Converted into a phase voltage (V)_R、V_S、V_T)；

According to the phase voltage (V)_R、V_S、V_T) Determining a voltage interval to which the phase voltage belongs;

carrying out three-phase voltage-two-phase voltage conversion on the phase voltage to obtain a voltage value (V) of a plane coordinate system_α、V_β)；

According to V_α、V_βAnd the affiliated voltage interval, and the output time ratio T of two non-zero vector voltages in the affiliated voltage interval is calculated by using a space vector method₁、T₂And a zero vector voltage output time ratio T_z；

Setting a PWM register in the controller according to a preset switch output mode and the output time ratio;

and the controller outputs PWM pulses according to the PWM register, controls and drives the matrix transformation switch module to act, and outputs the conversion voltage.

In the power conversion control method, the voltage interval includes six:

a first interval: v_R≥V_S≥V_T；

A second interval: v_S>V_R≥V_T；

The third interval: v_S≥V_T>V_R；

A fourth interval: v_T>V_S>V_R；

The fifth interval: v_T>V_R≥V_S；

A sixth interval: v_R≥V_T>V_S。

In the power supply changeover control method, the voltage value (V) of the plane coordinate system is controlled_α、V_β) Corrected voltage value (V)_α+、V_β+) For the corrected voltage value (V)_α+、V_β+) And the affiliated voltage interval, and the output time ratio T is calculated by using a space vector method₁、T₂、T_z。

The power supply changeover control method described above, the correction method being:

will V_α、V_βConversion to unit vector representation:

duty correction is carried out on the unit vector value:

the duty is a correction coefficient.

In the power supply changeover control method as described above, the output time ratio T is set to be smaller than the output time ratio T₁、T₂、T_zThe calculation method comprises the following steps:

voltage value (V) of the plane coordinate system_α、V_β) Or corrected voltage value (V)_α+、V_β+) The space basic vector voltage in the voltage interval is Vx,Vy, the action time of the space basic vector voltage Vx and the action time of the space basic vector voltage Vy are respectively T₁、T₂；

The component of Vx on α axis is V_1αThe component on the β axis being V_1β；

The component of Vy on the α axis is V_2αThe component on the β axis being V_2β；

T_z＝(1-(T₁+T₂))/2。

The power supply changeover control method as described above,

first interval (V)₁、V₂)：V_1α＝1；V_1β＝0；

Second interval (V)₂、V₃)：

Third interval (V)₃、V₄)：V_2α＝-1；V_2β＝0；

Fourth interval (V)₄、V5₎：V_1α＝-1；V_1β＝0；

Fifth interval (V)₅、V₆₎：

Sixth interval (V)₆、V₁)：V_2α＝1；V_2β＝0。

According to the power supply conversion control method, the PWM register in the controller is set, the commutation register is set at the same time, and the controller outputs PWM pulses according to the PWM register and the commutation register.

A power conversion control system, the control system comprising:

a matrix transformation switch module: for outputting a target voltage;

a control module for controlling the matrix-commutated switch module according to the method of any one of claims 1-7.

A computer-readable storage medium storing a computer program for use in conjunction with a matrix switch module, the computer program being executable by a processor to implement the method of any one of claims 1-7.

The invention has the beneficial effects that: the invention collects the input line voltage, converts the line voltage into the phase voltage, determines the voltage interval to which the phase voltage belongs, converts the phase voltage into the voltage value of the plane coordinate system, calculates the voltage vector output time ratio by using a space vector method for the voltage value of the plane coordinate system and the voltage interval to which the phase voltage belongs, can output the target PWM pulse only by setting a relevant register, controls and drives the matrix conversion switch module to carry out power conversion, reduces the hardware cost, reduces the volume and reduces the development difficulty of system software.

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 flow chart of an embodiment of the present invention.

FIG. 2 is a voltage division diagram according to an embodiment of the present invention.

FIG. 3 is a schematic diagram of space vectors according to an embodiment of the present invention.

FIG. 4 is a software logic diagram of an embodiment of the present invention.

FIG. 5 is a circuit diagram of an embodiment of the present invention.

Fig. 6 is a schematic diagram of a bidirectional switch of a matrix switch module according to an embodiment of the invention.

FIG. 7 shows the output mode of the bi-directional switch according to an embodiment of the present invention.

FIG. 8 is a timing diagram of a four-step commutation operation in 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.

As shown in fig. 1, the present embodiment provides a power conversion control method, including the following steps:

s1, collecting the line voltage (V) of the three-phase AC input_RS、V_ST、V_TR)。

Specifically, an input line voltage AD value is collected in real time through an AD module integrated with a controller (MCU) to obtain V_RS、V_ST、V_TRThen, it is determined whether or not there is an abnormality, and the process proceeds to step S2 for a normal case without processing the abnormal case.

S2, collecting the line voltage (V)_RS、V_ST、V_TR) Filter smoothness adjustment is performed by a first order low pass filtering (L PF) algorithm and the filtered line voltage is converted to a phase voltage (V)_R、V_S、V_T)。

A first-order low-pass filtering algorithm, Y (n) α x (n) + (1- α) Y (n-1);

wherein α is the filter coefficient, x (n) is the current sample value, Y (n-1) is the last filter output value, and Y (n) is the current filter output value.

The low-pass filtering algorithm has the characteristics that:

1. the smaller the filter coefficient, the smoother the filtering result, but the lower the sensitivity;

2. the larger the filter coefficient is, the higher the sensitivity is, but the more unstable the filtering result is;

and selecting a filter coefficient according to the characteristics of the filter algorithm and the actual data.

Line voltage → phase voltage conversion:

①V_RS＝V_R–V_S；

②V_ST＝V_S–V_T；

③V_TR＝V_T–V_R；

④V_R+V_S+V_T＝0；

①-②：

V_RS-V_ST＝V_R-V_S-V_S+V_T＝V_R-2V_S+V_T；

according to formula ④, V is_S＝(-1/3)*(V_RS-V_ST)；

Carry in ① to obtain V_R＝V_RS+(1/3)*(V_ST-V_RS)；

The same can be obtained: v_S＝V_ST+(1/3)*(V_TR-V_ST)；

V_T＝V_TR+(1/3)*(V_RS-V_TR)；

S3-1, according to phase voltage (V)_R、V_S、V_T) The voltage interval to which the phase voltages belong is determined.

As shown in fig. 2, the voltage intervals include six, and the voltage of one sinusoidal cycle is divided into 6 voltage intervals.

A first interval: v_R≥V_S≥V_T；

A second interval: v_S>V_R≥V_T；

The third interval: v_S≥V_T>V_R；

A fourth interval: v_T>V_S>V_R；

The fifth interval: v_T>V_R≥V_S；

A sixth interval: v_R≥V_T>V_S。

S3-2, carrying out three-phase voltage-two-phase voltage transformation on the phase voltage to obtain a voltage value (V) of a plane coordinate system_α、V_β)。

S3-3, voltage value (V) to plane coordinate system_α、V_β) Corrected voltage value (V)_α+、V_β+). To V_α、V_βDuty correction is performed to obtain V_α+V β + for adjusting the output voltage amplitude.

The correction method comprises the following steps:

will V_α、V_βConversion to unit vector representation:

duty correction is carried out on the unit vector value:

the duty is a correction coefficient by which the amplitude of the output voltage is adjusted.

S4, pair (V)_α+、V_β+) And a voltage section to which the voltage vector belongs, and calculating an output time ratio T of the voltage vector of the voltage section to which the voltage vector belongs by using a space vector method₁、T₂、T_z。

As shown in fig. 3, the basic vector voltage is subjected to component calculation on the α and β axes by using a space vector method, and the output time ratio T of 2 non-zero vector voltages is obtained₁、T₂And 1 output time ratio T of zero vector voltage_z。

Output time ratio T₁、T₂、T_zThe calculation method comprises the following steps:

setting the corrected voltage value (V)_α+、V_β+) The space basic vector voltage in the voltage range is Vx and Vy (the values of x and y are 1-6), and the respective action time is T₁、T₂；

Then:

the component of Vx on α axis is V_1αThe component on the β axis being V_1β；

The component of Vy on the α axis is V_2αThe component on the β axis being V_2β；

V_α+＝V_1αT₁+V_2αT₂

V_β+＝V_1βT₁+V_2βT₂

To obtain:

T_z＝(1-(T₁+T₂))/2

in the formula V_1α、V_1β、V_2α、V_2βThe difference is based on the difference of the basic vector voltage:

first interval (V)₁、V₂₎：V_1α＝1；V_1β＝0；

Second interval (V)₂、V₃)：

Third interval (V)₃、V₄)：V_2α＝-1；V_2β＝0；

Fourth interval (V)₄、V₅)：V_1α＝-1；V_1β＝0；

Fifth interval (V)₅、V₆)：

Sixth interval (V)₆、V₁)：V_2α＝1；V_2β＝0。

And S5, setting a PWM register in the controller according to the preset switch output mode and the output time ratio obtained in the step S4, and simultaneously setting a commutation register according to 4-step commutation of the existing voltage commutation method to ensure the safety of the bidirectional switch in the switching process.

Assuming that the current interval is 1 as shown in fig. 7 and the state of the bidirectional switch is from V8 → V2 as shown in fig. 6, the actual switching operation is Ssn1 and Ssn2 are turned off from on, and Stn1 and Stn2 are turned off from on, and the conventional four-step commutation operation is shown in fig. 8.

And S6, the controller outputs PWM pulses according to the PWM register and the commutation register, controls and drives the matrix transformation switch module to act, and outputs the transformation voltage.

As shown in fig. 4 and 5, the present embodiment further provides a power conversion control system, where the control system includes:

a matrix transformation switch module: the control module is used for receiving the three-phase alternating current input voltage, controlling the switching state and outputting a target voltage;

and the control module is used for controlling the switching state of the matrix transformation switching module by outputting the PWM pulse according to the method. A computer-readable storage medium storing a computer program for use in conjunction with a matrix switch module, the computer program being executable by a processor to implement the method described above.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.