CN112072936A - Rectification control method, system, equipment and computer readable storage medium - Google Patents
Rectification control method, system, equipment and computer readable storage medium Download PDFInfo
- Publication number
- CN112072936A CN112072936A CN202010805780.2A CN202010805780A CN112072936A CN 112072936 A CN112072936 A CN 112072936A CN 202010805780 A CN202010805780 A CN 202010805780A CN 112072936 A CN112072936 A CN 112072936A
- Authority
- CN
- China
- Prior art keywords
- phase
- voltage
- phase line
- switching tube
- controllable switching
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
- H02M7/02—Conversion of ac power input into dc power output without possibility of reversal
- H02M7/04—Conversion of ac power input into dc power output without possibility of reversal by static converters
- H02M7/12—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/21—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
- H02M7/217—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M7/219—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only in a bridge configuration
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/26—Arrangements for eliminating or reducing asymmetry in polyphase networks
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
- Y02E40/50—Arrangements for eliminating or reducing asymmetry in polyphase networks
Abstract
The invention provides a rectification control method, a system, equipment and a computer readable storage medium, wherein the method comprises the following operations executed on any controllable switching tube in a rectification circuit: acquiring the voltage of a phase line where the controllable switching tube is positioned, and judging whether the voltage of the phase line meets a preset condition or not; when the voltage of the phase line meets a preset condition, judging whether the unbalance coefficient of the phase line is larger than the unbalance coefficient of any other phase line in the rectifying circuit; and when the unbalance coefficient of the phase line is larger than that of any other phase line in the rectifying circuit, the controllable switching tube is driven to be conducted. According to the embodiment of the invention, the rectification control of the controllable switching tube can be realized without a phase-locked loop, and the rectification can be accurately controlled even when the power grid is abnormal in amplitude jump, harmonic distortion, phase loss, unbalance and the like, so that the power grid adaptability of the rectification of the controllable switching tube is improved.
Description
Technical Field
The embodiment of the invention relates to the field of power electronic equipment, in particular to a rectification control method, a system, equipment and a computer readable storage medium.
Background
A rectifying circuit (rectifying circuit) is a circuit that converts ac power into dc power, and is widely used in the fields of speed regulation of dc motors, excitation regulation of generators, electrolysis, electroplating, and the like.
According to different components and control modes, the rectification circuit can be divided into an uncontrollable rectification circuit, a semi-controlled rectification circuit and a fully-controlled rectification circuit, wherein the uncontrollable rectification circuit is completely composed of uncontrollable diodes, and the ratio of the direct-current rectification voltage to the alternating-current power supply voltage value is fixed after the circuit structure is fixed; the semi-controlled rectifier circuit is formed by mixing a controllable element and a diode, the polarity of a load power supply cannot be changed, but the average value is adjustable; all the rectifying elements in the fully-controlled rectifying circuit are controllable, and the average value and the polarity of the output direct-current voltage can be adjusted by controlling the conduction condition of the elements. In existing half-Controlled and full-Controlled Rectifier circuits, a Silicon Controlled Rectifier (SCR) is generally used as a controllable element.
As shown in fig. 1, a fully controlled rectifier circuit 10 is illustrated. The fully-controlled rectifier circuit 10 realizes rectification by controlling the conduction angle of the thyristor (the angle is 0 degree when the set voltage positive zero-crossing is zero), namely, the upper arm thyristor of each phase is driven to be conducted when the power grid voltage of each phase is 60 to 120 degrees, and the lower arm thyristor of each phase of the rectifier circuit is driven to be conducted when the power grid voltage of each phase is 210 to 330 degrees, so that the highest rectification voltage of the bus voltage is ensured.
When the thyristor is controlled to be conducted, a phase-locked loop needs to be designed, and if the voltage of the three-phase power grid is balanced, only the vector angle of the three-phase power grid needs to be locked. However, when the grid voltage is out of phase, unbalanced or the phase sequence is opposite, the vector angle of the three-phase grid voltage cannot represent the real phase angle of each phase, and the three-phase grid voltage needs to be phase-locked respectively. And when the voltage of the power grid is distorted, the phase-locked loop fails to lock the phase, so that the rectification work is abnormal.
Disclosure of Invention
The embodiment of the invention provides a novel rectification control method, a novel rectification control system, a novel rectification control device and a novel computer-readable storage medium, aiming at the problems that in the thyristor conduction control by adopting a phase-locked loop, the vector angle of a three-phase power grid cannot represent the real angle of each phase when the voltage of the power grid is in phase loss or unbalance or when the phase sequence is opposite, and the phase-locked loop fails to lock the phase when the voltage of the power grid is distorted.
In order to solve the above technical problem, an embodiment of the present invention provides a rectification control method for driving and controlling a controllable switching tube in a rectification circuit to convert an input ac power into a dc power, where the method includes the following operations performed on any controllable switching tube in the rectification circuit:
acquiring the voltage of a phase line where the controllable switching tube is positioned, and judging whether the voltage of the phase line meets a preset condition or not;
when the voltage of the phase line meets a preset condition, judging whether the unbalance coefficient of the phase line is larger than the unbalance coefficient of any other phase line in the rectifying circuit or not and whether the unbalance coefficient of the phase line is larger than a preset threshold or not;
and when the unbalance coefficient of the phase line is larger than that of any other phase line in the rectifying circuit or the unbalance coefficient of the phase line is larger than a preset threshold value, driving the controllable switching tube to be conducted.
Preferably, the method further comprises the following operations performed on each phase line in the rectification circuit:
sampling every two zero-crossing points of phase voltages of the phase lines at a preset period to obtain a plurality of phase voltage instantaneous values;
calculating the voltage effective value of the phase line according to the phase voltage instantaneous values;
and calculating the unbalance coefficient of the phase line according to the effective voltage value of the phase line and the effective voltage values of other phase lines in the rectifying circuit.
Preferably, the controllable switching tube is located in an upper bridge arm of the phase line, and the determining whether the voltage of the phase line meets a preset condition includes:
and judging whether the phase voltage of the phase line is the largest one of the phase voltages of all the phase lines or not, and judging that the voltage of the phase line does not meet the preset condition when the phase voltage of the phase line is not the largest one of the phase voltages of all the phase lines.
Preferably, the controllable switching tube is located in a lower bridge arm of the phase line, and the determining whether the voltage of the phase line meets a preset condition includes:
and judging whether the phase voltage of the phase lines is the minimum one of the phase voltages of all the phase lines or not, and judging that the voltage of the phase lines does not meet the preset condition when the phase voltage of the phase lines is not the minimum one of the phase voltages of all the phase lines.
Preferably, the controllable switching tube is located in a lower bridge arm of the phase line, and the determining whether the voltage of the phase line meets a preset condition includes:
and judging whether the voltage zero crossing of the phase line is normal or not, and judging that the voltage of the phase line does not accord with a preset condition when the voltage zero crossing of the phase line is abnormal.
The embodiment of the present invention further provides a rectification control system, configured to perform drive control on a controllable switching tube in a rectification circuit, so that the rectification circuit converts input ac power into dc power, where the system includes a first determining unit, a second determining unit, and a switch driving unit, where:
the first judging unit is used for judging whether the voltage of the phase line of the controllable switching tube meets a preset condition or not;
the second judging unit is used for further judging whether the imbalance coefficient of the phase line of the controllable switching tube is larger than the imbalance coefficient of any other phase line in the rectifying circuit or not and whether the imbalance coefficient of the phase line is larger than a preset threshold value or not when the voltage of the phase line of the controllable switching tube meets a preset condition;
the switch driving unit is used for driving the controllable switch tube to be conducted when the unbalance coefficient of the phase line where the controllable switch tube is located is larger than the unbalance coefficient of any other phase line in the rectification circuit or the unbalance coefficient of the phase line is larger than a preset threshold value.
Preferably, the rectification control system further includes a zero-crossing point judgment unit, a sampling unit, a first calculation unit, and a second calculation unit, wherein:
the zero crossing point judging unit is used for acquiring each zero crossing point of the phase voltage of the phase line;
the sampling unit is used for sampling between two zero-crossing points of phase voltages of the phase lines in a preset period to obtain a plurality of phase voltage instantaneous values;
the first calculating unit is used for calculating the voltage effective value of the phase line according to the phase voltage instantaneous value between two zero-crossing points;
and the second calculating unit is used for calculating the unbalance coefficient of the phase line according to the effective voltage value of the phase line and the effective voltage values of other phase lines in the rectifying circuit.
Preferably, the first judging unit includes a first subunit and a second subunit, wherein:
the first subunit is used for judging whether the voltage zero crossing of the phase line is normal or not, and judging that the voltage of the phase line does not accord with a preset condition when the voltage zero crossing of the phase line is abnormal;
the second subunit is used for judging that the voltage of the phase line does not meet a preset condition when the controllable switching tube is positioned on an upper bridge arm of the phase line and the phase voltage of the phase line is not the largest one of the phase voltages of all the phase lines; and when the controllable switching tube is positioned at the lower bridge arm of the phase lines and the phase voltage of the phase lines is not the minimum one of the phase voltages of all the phase lines, judging that the voltage of the phase lines does not meet the preset condition.
The embodiment of the present invention further provides a rectification control device, which includes a memory and a processor, where the memory stores a computer program operable on the processor, and the processor implements the steps of the rectification control method when executing the computer program.
An embodiment of the present invention further provides a computer-readable storage medium, where a computer program is stored on the computer-readable storage medium, and when the computer program is executed by a processor, the steps of the rectification control method are implemented.
According to the rectification control method, the rectification control system, the rectification control equipment and the computer readable storage medium, when the voltage of the phase line of the controllable switching tube meets the preset condition and the imbalance coefficient is not the lowest, the controllable switching tube is driven to be conducted, the power supply of the bus is ensured to be supplied by the maximum voltage, so that the rectification control of the controllable switching tube can be realized without a phase-locked loop, the rectification can be accurately controlled even when the power grid is abnormal in amplitude jump, harmonic distortion, phase loss, imbalance and the like, and the power grid adaptability of the rectification of the controllable switching tube is improved.
Drawings
FIG. 1 is a schematic diagram of a prior art three-phase fully controlled rectifier circuit;
FIG. 2 is a schematic flow chart of a rectification control method according to an embodiment of the present invention;
fig. 3 is a schematic flow chart of obtaining a phase line imbalance coefficient in a rectification control method according to an embodiment of the present invention;
fig. 4 is a schematic flowchart of a process for controlling a controllable switching tube located in an upper bridge arm in a rectification control method according to an embodiment of the present invention;
fig. 5 is a schematic flowchart of a process for controlling a controllable switching tube located in a lower bridge arm in a rectification control method according to an embodiment of the present invention;
fig. 6 is a schematic diagram of a relationship between a wave-generating signal and a phase voltage for driving a controllable switching tube in a three-phase full-bridge rectification circuit to be conducted by the rectification control method provided by the embodiment of the present invention;
FIG. 7 is a schematic diagram of a commutation control system provided by an embodiment of the invention;
fig. 8 is a schematic diagram of a rectification control device according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
As shown in fig. 2, the flow chart of the rectification control method according to the embodiment of the present invention is a flow chart of the rectification control method, where the rectification control method is used to drive and control a controllable switching tube in a rectification circuit, so that the rectification circuit converts an input ac power into a dc power, where the controllable switching tube may be a thyristor, a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), an IGBT (Insulated Gate Bipolar Transistor), or the like. The input end of the rectifying circuit is connected to an alternating current voltage line (such as a power grid), the output end of the rectifying circuit is connected with a direct current bus, and the rectifying circuit can be specifically a three-phase half-bridge rectifying circuit, a three-phase full-bridge half-control rectifying circuit, a three-phase full-bridge full-control rectifying circuit, a single-phase half-bridge rectifying circuit, a single-phase full-bridge half-control rectifying circuit, a single-phase.
The method of the embodiment can be specifically integrated into a controller of the power electronic device, and realizes rectification control by outputting the driving current to the control end of the controllable switching tube in the rectification circuit. Specifically, the method of the present embodiment includes the following operations performed on any controllable switching tube in the rectifier circuit:
step S21: and acquiring the voltage of a phase line where the controllable switching tube is positioned, and judging whether the voltage of the phase line meets a preset condition.
The step can be judged through the phase voltage of the phase line where the controllable switching tube is located, namely whether the phase voltage of the phase line meets the preset condition is judged. Since ac voltage, such as grid voltage, can only be sampled, it is necessary to first sample the line voltage at the ac input of the rectifier circuit. For example, when the rectifier circuit is a three-phase rectifier circuit, the input end of the rectifier circuit is connected with an a-phase line, a B-phase line and a C-phase line respectively, and in the step, line sampling is required to obtain line voltages Uab, Ubc and Uca of the three-phase lines. Since the three line voltages satisfy the following equations (1) to (5):
Uab＝Ua-Ub (1)
Ubc＝Ub-Uc 2)
Uca＝Uc-Ua (3)
Uab+Ubc+Uca＝0 (4)
Ua+Ub+Uc＝0 (5)
the above-mentioned Ua, Ub, Uc are the original phase voltages of the phase line a, phase line B, phase line C respectively (the voltage saw teeth and small jump can be filtered by low pass filtering).
The original phase voltages Ua, Ub, Uc of the three-phase lines can thus be calculated from the line voltages Uab, Ubc, Uca by the following equations (6) to (8):
Ua＝(Uab–Uca)/3 (6)
Ub＝(Ubc–Uab)/3 (7)
Uc＝(Uca–Ubc)/3 (8)
the preset conditions may specifically include a first preset condition and a second preset condition, and it is determined that the voltage of the phase line meets the preset conditions only when the phase voltage of the phase line meets the first preset condition and the second preset condition at the same time. The first preset condition is different according to the position of the controllable switching tube, for example, when the controllable switching tube is located in the upper bridge arm of the rectification circuit, the phase voltage of the phase line is the maximum value of the phase voltages of all the phase lines; when the controllable switching tube is located at the lower bridge arm of the rectification circuit, the first preset condition is that the phase voltage of the phase lines is the minimum value of the phase voltages of all the phase lines. The second preset condition may be that the zero crossing of the phase voltage is normal (if phase loss occurs, the voltage of the phase line is consistent with the voltage of the bus, and no zero crossing point exists).
Certainly, in practical application, it may also be determined whether the voltage of the phase line meets the preset condition according to the line voltage, for example, when the absolute value of the line voltage Uab is maximum and positive, the phase line where the controllable switching tube of the upper bridge arm of the phase a is located and the phase line where the controllable switching tube of the lower bridge arm of the phase B meets the first preset condition.
Step S22: and when the voltage of the phase line meets the preset condition, judging whether the unbalance coefficient of the phase line is larger than the unbalance coefficient of any other phase line in the rectifying circuit.
Specifically, the imbalance coefficient may be a ratio of an imbalance coefficient of the current phase line to an average value of imbalance coefficients of all phase lines. And, whether a certain phase line is abnormal can be determined through the unbalance coefficient of the phase lines: when the unbalanced coefficient of a certain phase line is the lowest one of the unbalanced coefficients of all the phase lines and is lower than a preset threshold value, the phase line can be judged to be abnormal, the controllable switch tube on the phase line can be controlled to be kept disconnected and corresponding alarm signals can be output, and the bus voltage cannot be improved even if the controllable switch tube on the phase line is connected because the effective value of the phase voltage of the phase line is obviously lower.
Step S23: and when the unbalance coefficient of the phase line is larger than that of any other phase line in the rectifying circuit, the controllable switch tube is driven to be conducted.
Specifically, the controllable switch tube can be turned on by outputting a pulse width modulation signal to the control end of the controllable switch tube. Of course, in practical applications, the controllable switch tube may also be driven to be turned on by outputting a constant dc current to the control end of the controllable switch tube.
According to the rectification control method, when the voltage of the phase line where the controllable switching tube is located meets the preset condition and the imbalance coefficient is not the lowest, the controllable switching tube is driven to be conducted, the maximum voltage is guaranteed to supply power to the bus, so that rectification control of the controllable switching tube can be achieved without a phase-locked loop, rectification can be accurately controlled even when the power grid is abnormal in amplitude jump, harmonic distortion, phase loss, imbalance and the like, and the power grid adaptability of rectification of the controllable switching tube is improved.
Fig. 3 is a schematic flow chart illustrating a process of obtaining an imbalance coefficient in a rectification control method according to an embodiment of the present invention, where the rectification control method needs to obtain an imbalance coefficient of a phase line where each controllable switching transistor is located. The following method for obtaining the imbalance coefficient in this embodiment is described by taking the phase a of the three-phase rectifier circuit as an example:
step S221: a plurality of phase voltage instantaneous values are obtained by sampling at preset periods between every two zero-crossing points of the A phase voltage.
Specifically, when the last (i.e., the previous sampling period) voltage value of the a-phase voltage Ua is smaller than 0 and the next (i.e., the current sampling period) voltage value is larger than 0, the a-phase voltage Ua is recorded as the zero crossing. Every time the A phase voltage crosses zero (namely, the A phase voltage zero crossing is detected), the A phase voltage period counter is started to count from 0 (namely, counting is started after zero clearing), and counting is finished until the next zero crossing, so that the counting value N of the A phase voltage in one period is obtained.
While counting, samplingInstantaneous value y of phase voltage at each counting point1，y2，y3，…，yN. Because the voltage frequency of the power grid is basically fixed, the zero-crossing count value can be limited (for example, counting is stopped when the count value exceeds a preset value, and an error is reported), so that the zero-crossing judgment failure and the effective value calculation failure caused by the fact that a certain phase of power grid does not cross zero when the power grid is powered off or the phase lack abnormality occurs are prevented.
Step S222: and calculating the effective voltage value of the phase line according to the plurality of phase voltage instantaneous values. Specifically, the effective value Ua _ rms of the voltage of the a phase can be obtained by calculation by the following calculation formula (9):
and respectively calculating the voltage effective value of each phase line of the input end of the three-phase rectification circuit to obtain the voltage effective value Ub _ rms of the phase B and the voltage effective value Uc _ rms of the phase C.
Step S223: and calculating the imbalance coefficient of the phase line according to the effective voltage value of the phase line and the effective voltage values of other phase lines in the rectifying circuit. Specifically, the voltage unbalance coefficient Ka of the a-phase line, the voltage unbalance coefficient Kb of the B-phase line, and the voltage unbalance coefficient Kc of the C-phase line can be obtained by calculation according to the following calculation formulas (10) to (12):
Ka＝Ua_rms/(Ua_rms+Ub_rms+Uc_rms)/3 (10)
Kb＝Ub_rms/(Ua_rms+Ub_rms+Uc_rms)/3 (11)
Kc＝Uc_rms/(Ua_rms+Ub_rms+Uc_rms)/3 (12)
in step S223, it may be determined whether the imbalance coefficient of a certain phase is the lowest and lower than a certain threshold, and if the imbalance coefficient of a certain phase is the lowest and lower than the certain threshold, it may be determined that the certain phase is an abnormal phase, and alarm information may be output. The phase voltage of the abnormal phase is significantly lower in effective value and may not be conducted (even if the phase is conducted, since the phase voltage is always lower than the bus voltage, the bus cannot be boosted, and the conduction is ineffective).
Step S23 in fig. 2 can use the imbalance coefficients obtained in steps S221 to S223 described above to make a corresponding determination. Of course, in practical applications, the imbalance coefficient may be obtained in other manners.
Fig. 4 is a schematic flow chart illustrating a process of controlling a controllable switching tube located in an upper bridge arm in the rectification control method according to the embodiment of the present invention. Specifically, the following describes the control of the controllable switching tube located in the upper arm in this embodiment, taking the controllable switching tube of the upper arm in phase a in the three-phase rectification circuit as an example:
step S41: and judging whether the phase voltage Ua of the phase line A is the largest one of the phase voltages of all the phase lines, if the phase voltage Ua of the phase line A is the largest one of the phase voltages of all the phase lines, namely Ua > Ub and Ua > Uc, executing the step S42, otherwise executing the step S45.
Step S42: whether the voltage zero-crossing of the phase a is normal can be determined, for example, by determining whether a count value from the zero-crossing point exceeds a preset value. Step S43 is performed when the voltage zero-crossing of the a-phase is normal, otherwise step S45 is performed.
Step S43: it is further determined whether the a-phase imbalance coefficient is not the minimum and whether the a-phase imbalance coefficient is greater than a preset threshold (the preset threshold may be set as needed, for example, may be set to 0.5), and when the a-phase imbalance coefficient is greater than any one of the B-phase imbalance coefficient and the C-phase imbalance coefficient, or the a-phase imbalance coefficient is greater than the preset threshold, step S44 is performed, otherwise, step S45 is performed.
Step S44: and driving the controllable switch tube of the A-phase upper bridge arm to be conducted (the controllable switch tube of the A-phase lower bridge arm is disconnected).
Step S45: and driving the controllable switching tube of the upper bridge arm of the phase A to be disconnected.
The instantaneous maximum value of the phase voltage of each phase line is utilized to control the wave generation to conduct the controllable switching tube of the upper bridge arm, so that the phase calculation is avoided. Specifically, referring to fig. 6, in the sequence of fig. 6, a three-phase line voltage curve, a three-phase voltage curve, a phase a upper bridge arm controllable switching tube driving signal (a dark color is an upper bridge arm switching tube conducting signal, and a light color is a lower bridge arm switching tube conducting signal), a phase B upper bridge arm controllable switching tube driving signal (a dark color is an upper bridge arm switching tube conducting signal, and a light color is a lower bridge arm switching tube conducting signal), and a phase C upper bridge arm controllable switching tube driving signal (a dark color is an upper bridge arm switching tube conducting signal, and a light color is a lower bridge arm switching tube conducting signal) are shown from top to bottom.
Similarly, as shown in fig. 5, the schematic flowchart of the rectification control method provided in the embodiment of the present invention is used to control the controllable switching tube located in the lower bridge arm. Specifically, the following describes the control of the controllable switching tube located in the lower arm in this embodiment, taking the controllable switching tube of the lower arm in phase a in the three-phase rectification circuit as an example:
step S51: and judging whether the phase voltage Ua of the phase line A is the minimum phase voltage of all the phase lines, if the phase voltage Ua of the phase line A is the minimum phase voltage of all the phase lines, namely Ua is less than Ub and Ua is less than Uc, executing the step S52, otherwise executing the step S55.
Step S52: whether the voltage zero-crossing of the phase a is normal can be determined, for example, by determining whether a count value from the zero-crossing point exceeds a preset value. Step S53 is performed when the voltage zero-crossing of the a-phase is normal, otherwise step S55 is performed.
Step S53: it is further determined whether the a-phase imbalance coefficient is not the minimum and whether the a-phase imbalance coefficient is greater than a preset threshold (the preset threshold may be set as needed, for example, may be set to 0.5), and when the a-phase imbalance coefficient is greater than any one of the B-phase imbalance coefficient and the C-phase imbalance coefficient, or the a-phase imbalance coefficient is greater than the preset threshold, step S54 is performed, otherwise, step S55 is performed.
Step S54: and driving the controllable switch tube of the A-phase lower bridge arm to be conducted (the controllable switch tube of the A-phase upper bridge arm is disconnected).
Step S55: and driving the controllable switching tube of the A-phase lower bridge arm to be disconnected.
The instantaneous minimum value of the phase voltage of each phase line is utilized to control wave generation to enable a controllable switching tube of an upper bridge arm to be conducted, and therefore phase calculation is avoided.
As shown in fig. 7, an embodiment of the present invention further provides a rectification control system, which is configured to perform drive control on a controllable switching tube in a rectification circuit, so that the rectification circuit converts an input alternating current into a direct current. The rectification control system of the present embodiment includes a first determining unit 71, a second determining unit 72, and a switch driving unit 73, and the first determining unit 71, the second determining unit 72, and the switch driving unit 73 may be implemented by combining software running on a controller of the power electronic device.
The first determining unit 71 is configured to determine whether a voltage of a phase line of the controllable switch tube meets a preset condition. Specifically, the first determining unit 71 may determine the phase voltage of the phase line where the controllable switching tube is located, that is, determine whether the phase voltage of the phase line meets the preset condition.
The preset conditions may specifically include a first preset condition and a second preset condition, and it is determined that the voltage of the phase line meets the preset conditions only when the phase voltage of the phase line meets the first preset condition and the second preset condition at the same time. The first preset condition is different according to the position of the controllable switching tube, for example, when the controllable switching tube is located in the upper bridge arm of the rectification circuit, the phase voltage of the phase line is the maximum value of the phase voltages of all the phase lines; when the controllable switching tube is located at the lower bridge arm of the rectification circuit, the first preset condition is that the phase voltage of the phase lines is the minimum value of the phase voltages of all the phase lines. The second preset condition may be that the zero crossing of the phase voltage is normal (if phase loss occurs, the voltage of the phase line is consistent with the voltage of the bus, and no zero crossing point exists).
Certainly, in practical application, it may also be determined whether the voltage of the phase line meets the preset condition according to the line voltage, for example, when the absolute value of the line voltage Uab is maximum and positive, the phase line where the controllable switching tube of the upper bridge arm of the phase a is located and the phase line where the controllable switching tube of the lower bridge arm of the phase B meets the first preset condition.
The second determining unit 72 is configured to further determine whether the imbalance coefficient of the phase line of the controllable switching tube is greater than the imbalance coefficient of any other phase line in the rectifier circuit and whether the imbalance coefficient of the phase a is greater than a preset threshold (the preset threshold may be set as needed, for example, may be set to 0.5) when the voltage of the phase line of the controllable switching tube meets a preset condition. Specifically, the imbalance coefficient may be a ratio of an imbalance coefficient of the current phase line to an average value of imbalance coefficients of all phase lines.
The switch driving unit 73 is configured to drive the controllable switching tube to be turned on when an imbalance coefficient of a phase line where the controllable switching tube is located is greater than an imbalance coefficient of any other phase line in the rectification circuit, or the imbalance coefficient of the phase line is greater than a preset threshold. Specifically, the switch driving unit 73 can drive the controllable switch to be turned on by outputting a pulse width modulation signal to the control terminal of the controllable switch. Of course, in practical applications, the switch driving unit 73 may also drive the controllable switch to be turned on by outputting a constant dc current to the control end of the controllable switch.
In addition, the rectification control system may further include a zero-crossing point judgment unit, a sampling unit, a first calculation unit, and a second calculation unit, and the zero-crossing point judgment unit, the sampling unit, the first calculation unit, and the second calculation unit may also be implemented in combination with software running on a controller of the power electronic device.
The zero crossing point judging unit is used for acquiring each zero crossing point of the phase voltage of the phase line (when the last voltage value of the phase voltage is less than 0 and the next voltage value is greater than 0, the zero crossing point of the phase voltage). The sampling unit is used for sampling between two zero-crossing points of the phase voltage in a preset period to obtain a plurality of phase voltage instantaneous values. The first calculating unit is used for calculating the effective voltage value of the phase line according to the instantaneous phase voltage value between the two zero-crossing points, for example according to the calculation formula (9). The second calculating unit is used for calculating the unbalance coefficient of the phase line according to the effective voltage value of the phase line and the effective voltage values of other phase lines in the rectifying circuit.
In addition, the first determining unit 71 may specifically include a first subunit and a second subunit, where the first subunit is configured to determine whether the zero-crossing of the phase line voltage is normal, and determine that the phase line voltage does not meet a preset condition when the zero-crossing of the phase line voltage is abnormal; the second subunit is used for judging that the voltage of the phase line does not meet the preset condition when the controllable switching tube is positioned on the upper bridge arm of the phase line and the phase voltage of the phase line is not the largest one of the phase voltages of all the phase lines; and the second subunit also judges that the voltage of the phase line does not meet the preset condition when the controllable switching tube is positioned at the lower bridge arm of the phase line and the phase voltage of the phase line is not the minimum one of the phase voltages of all the phase lines.
The rectification control system in this embodiment and the rectification control method in the embodiment corresponding to fig. 2 to 6 belong to the same concept, and specific implementation processes thereof are detailed in the corresponding method embodiments, and technical features in the method embodiments are correspondingly applicable in this system embodiment, and are not described herein again.
The embodiment of the present invention further provides a rectification control device 8, which may be specifically configured by a power electronic device controller, as shown in fig. 8, where the rectification control device 8 includes a memory 81 and a processor 82, the memory 81 stores a computer program executable by the processor 82, and the processor 82 implements the steps of the rectification control method described above when executing the computer program.
The rectification control device 8 in this embodiment is the same as the rectification control method in the embodiment corresponding to fig. 2 to 6, and the specific implementation process thereof is described in detail in the corresponding method embodiment, and the technical features in the method embodiment are correspondingly applicable in this device embodiment, which is not described herein again.
An embodiment of the present invention further provides a computer-readable storage medium, where a computer program is stored on the storage medium, and when the computer program is executed by a processor, the steps of the rectification control method described above are implemented.
The computer-readable storage medium in this embodiment is the same as the rectification control method in the embodiment corresponding to fig. 2 to 6, and the specific implementation process thereof is described in detail in the corresponding method embodiment, and the technical features in the method embodiment are correspondingly applicable in this device embodiment, which is not described herein again.
It should be understood that, the sequence numbers of the steps in the foregoing embodiments do not imply an execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.
It is obvious to those skilled in the art that, for convenience and simplicity of description, the foregoing functional units and modules are merely illustrated in terms of division, and in practical applications, the foregoing functions may be distributed as needed by different functional units and modules. Each functional unit and module in the embodiments may be integrated in one processor, or each unit may exist alone physically, or two or more units are integrated in one unit, and the integrated unit may be implemented in a form of hardware, or in a form of software functional unit. In addition, specific names of the functional units and modules are only for convenience of distinguishing from each other, and are not used for limiting the protection scope of the present application. The specific working processes of the units and modules in the system may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.
In the above embodiments, the descriptions of the respective embodiments have respective emphasis, and reference may be made to the related descriptions of other embodiments for parts that are not described or illustrated in a certain embodiment.
Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.
In the embodiments provided in the present application, it should be understood that the disclosed commutation control method, system and apparatus can be implemented in other ways. For example, the rectification control system embodiments described above are merely illustrative.
In addition, functional units in the embodiments of the present application may be integrated into one processor, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.
The integrated modules/units, if implemented in the form of software functional units and sold or used as separate products, may be stored in a computer readable storage medium. Based on such understanding, all or part of the flow in the method of the embodiments described above can be realized by a computer program, which can be stored in a computer-readable storage medium and can realize the steps of the embodiments of the methods described above when the computer program is executed by a processor. Wherein the computer program comprises computer program code, which may be in the form of source code, object code, an executable file or some intermediate form, etc. The computer-readable medium may include: any physical or interface switching device, recording medium, usb disk, removable hard disk, magnetic disk, optical disk, computer Memory, Read-Only Memory (ROM), Random Access Memory (RAM), electrical carrier wave signal, telecommunication signal, software distribution medium, etc., capable of carrying said computer program code. It should be noted that the computer readable medium may contain other components which may be suitably increased or decreased as required by legislation and patent practice in jurisdictions, for example, in some jurisdictions, computer readable media which may not include electrical carrier signals and telecommunications signals in accordance with legislation and patent practice.
The above-mentioned embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should 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; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present application and are intended to be included within the scope of the present application.
Claims (10)
1. A rectification control method for performing drive control on controllable switching tubes in a rectification circuit to make the rectification circuit convert input alternating current into direct current, the method comprising the following operations performed on any controllable switching tube in the rectification circuit:
acquiring the voltage of a phase line where the controllable switching tube is positioned, and judging whether the voltage of the phase line meets a preset condition or not;
when the voltage of the phase line meets a preset condition, judging whether the unbalance coefficient of the phase line is larger than the unbalance coefficient of any other phase line in the rectifying circuit or not and whether the unbalance coefficient of the phase line is larger than a preset threshold or not;
and when the unbalance coefficient of the phase line is larger than that of any other phase line in the rectifying circuit or the unbalance coefficient of the phase line is larger than a preset threshold value, driving the controllable switching tube to be conducted.
2. The commutation control method of claim 1, further comprising, for each phase line in the rectifier circuit:
sampling every two zero-crossing points of phase voltages of the phase lines at a preset period to obtain a plurality of phase voltage instantaneous values;
calculating the voltage effective value of the phase line according to the phase voltage instantaneous values;
and calculating the unbalance coefficient of the phase line according to the effective voltage value of the phase line and the effective voltage values of other phase lines in the rectifying circuit.
3. The rectification control method of claim 1, wherein the controllable switching tube is located in an upper bridge arm of the phase line, and the determining whether the voltage of the phase line meets a preset condition includes:
and judging whether the phase voltage of the phase line is the largest one of the phase voltages of all the phase lines or not, and judging that the voltage of the phase line does not meet the preset condition when the phase voltage of the phase line is not the largest one of the phase voltages of all the phase lines.
4. The rectification control method of claim 1, wherein the controllable switching tube is located in a lower bridge arm of the phase line, and the determining whether the voltage of the phase line meets a preset condition includes:
and judging whether the phase voltage of the phase lines is the minimum one of the phase voltages of all the phase lines or not, and judging that the voltage of the phase lines does not meet the preset condition when the phase voltage of the phase lines is not the minimum one of the phase voltages of all the phase lines.
5. The rectification control method according to claim 3 or 4, wherein the controllable switching tube is located in a lower bridge arm of the phase line, and the determining whether the voltage of the phase line meets a preset condition includes:
and judging whether the voltage zero crossing of the phase line is normal or not, and judging that the voltage of the phase line does not accord with a preset condition when the voltage zero crossing of the phase line is abnormal.
6. A rectification control system for performing drive control on a controllable switching tube in a rectification circuit to enable the rectification circuit to convert input alternating current into direct current, the system is characterized by comprising a first judgment unit, a second judgment unit and a switch driving unit, wherein:
the first judging unit is used for judging whether the voltage of the phase line of the controllable switching tube meets a preset condition or not;
the second judging unit is used for further judging whether the imbalance coefficient of the phase line of the controllable switching tube is larger than the imbalance coefficient of any other phase line in the rectifying circuit or not and whether the imbalance coefficient of the phase line is larger than a preset threshold value or not when the voltage of the phase line of the controllable switching tube meets a preset condition;
the switch driving unit is used for driving the controllable switch tube to be conducted when the unbalance coefficient of the phase line where the controllable switch tube is located is larger than the unbalance coefficient of any other phase line in the rectification circuit or the unbalance coefficient of the phase line is larger than a preset threshold value.
7. The rectification control system according to claim 6, further comprising a zero-crossing point judgment unit, a sampling unit, a first calculation unit, and a second calculation unit, wherein:
the zero crossing point judging unit is used for acquiring each zero crossing point of the phase voltage of the phase line;
the sampling unit is used for sampling between two zero-crossing points of phase voltages of the phase lines in a preset period to obtain a plurality of phase voltage instantaneous values;
the first calculating unit is used for calculating the voltage effective value of the phase line according to the phase voltage instantaneous value between two zero-crossing points;
and the second calculating unit is used for calculating the unbalance coefficient of the phase line according to the effective voltage value of the phase line and the effective voltage values of other phase lines in the rectifying circuit.
8. The commutation control system of claim 6, wherein the first determining unit comprises a first sub-unit and a second sub-unit, and wherein:
the first subunit is used for judging whether the voltage zero crossing of the phase line is normal or not, and judging that the voltage of the phase line does not accord with a preset condition when the voltage zero crossing of the phase line is abnormal;
the second subunit is used for judging that the voltage of the phase line does not meet a preset condition when the controllable switching tube is positioned on an upper bridge arm of the phase line and the phase voltage of the phase line is not the largest one of the phase voltages of all the phase lines; and when the controllable switching tube is positioned at the lower bridge arm of the phase lines and the phase voltage of the phase lines is not the minimum one of the phase voltages of all the phase lines, judging that the voltage of the phase lines does not meet the preset condition.
9. A commutation control apparatus, comprising a memory and a processor, the memory having stored therein a computer program operable on the processor, the processor implementing the steps of the commutation control method according to any one of claims 1 to 5 when executing the computer program.
10. A computer-readable storage medium, having stored thereon a computer program which, when executed by a processor, carries out the steps of the commutation control method of any one of claims 1 to 5.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010805780.2A CN112072936B (en) | 2020-08-11 | 2020-08-11 | Rectification control method, system, equipment and computer readable storage medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010805780.2A CN112072936B (en) | 2020-08-11 | 2020-08-11 | Rectification control method, system, equipment and computer readable storage medium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112072936A true CN112072936A (en) | 2020-12-11 |
| CN112072936B CN112072936B (en) | 2022-04-29 |
Family
ID=73661237
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010805780.2A Active CN112072936B (en) | 2020-08-11 | 2020-08-11 | Rectification control method, system, equipment and computer readable storage medium |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112072936B (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101515760A (en) * | 2008-02-21 | 2009-08-26 | 北京信息工程学院 | Passivity-based control system for voltage type PWM rectifier supplied by unbalanced power supply |
| US20130063981A1 (en) * | 2011-09-08 | 2013-03-14 | Abb Technology Ag | Multilevel converter and a control method for operating a multilevel converter |
| CN104362759A (en) * | 2014-12-10 | 2015-02-18 | 国家电网公司 | Final power quality regulating and controlling device for power distribution network and regulating and controlling method |
| CN205753433U (en) * | 2016-05-17 | 2016-11-30 | 天津市三源电力设备制造有限公司 | It is applied to the device administering three-phase imbalance of low-voltage distribution network |
| CN107317352A (en) * | 2017-06-22 | 2017-11-03 | 南京工程学院 | Miniature photovoltaic DC-to-AC converter control method with three-phase imbalance abatement functions |
-
2020
- 2020-08-11 CN CN202010805780.2A patent/CN112072936B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101515760A (en) * | 2008-02-21 | 2009-08-26 | 北京信息工程学院 | Passivity-based control system for voltage type PWM rectifier supplied by unbalanced power supply |
| US20130063981A1 (en) * | 2011-09-08 | 2013-03-14 | Abb Technology Ag | Multilevel converter and a control method for operating a multilevel converter |
| CN104362759A (en) * | 2014-12-10 | 2015-02-18 | 国家电网公司 | Final power quality regulating and controlling device for power distribution network and regulating and controlling method |
| CN205753433U (en) * | 2016-05-17 | 2016-11-30 | 天津市三源电力设备制造有限公司 | It is applied to the device administering three-phase imbalance of low-voltage distribution network |
| CN107317352A (en) * | 2017-06-22 | 2017-11-03 | 南京工程学院 | Miniature photovoltaic DC-to-AC converter control method with three-phase imbalance abatement functions |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112072936B (en) | 2022-04-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN100590959C (en) | Power supply circuit protecting method and apparatus for the same | |
| US10630163B2 (en) | Pulse width modulation method, pulse width modulation system, and controller | |
| US7170767B2 (en) | System and method for regenerative PWM AC power conversion | |
| Cho | DSP based space vector PWM for three-level inverter with DC-link voltage balancing | |
| US6556464B2 (en) | PWM converter system | |
| US7881081B1 (en) | Systems and methods for reducing AC drive common-mode currents | |
| Sabarad et al. | Comparative analysis of SVPWM and SPWM techniques for multilevel inverter | |
| US20040160207A1 (en) | Method and apparatus for controlling reflected voltage using a motor controller | |
| KR20080109878A (en) | Power converter | |
| US11205952B2 (en) | Methods and systems for controlling current source rectifiers | |
| US10348127B2 (en) | Three-phase uninterruptible power supply control method and apparatus, and three-phase uninterruptible power supply responsive to zero wire loss | |
| Ben-Brahim | A discontinuous PWM method for balancing the neutral point voltage in three-level inverter-fed variable frequency drives | |
| Blaabjerg et al. | An integrated high power factor three-phase AC-DC-AC converter for AC-machines implemented in one microcontroller | |
| CN113014124A (en) | Power conversion device | |
| CN1066754A (en) | Inverter and AC motor drive system | |
| US11646676B2 (en) | Method and apparatus for generating a three-phase voltage | |
| EP0383949A1 (en) | Current limiting system for a voltage-type inverter | |
| CN112072936B (en) | Rectification control method, system, equipment and computer readable storage medium | |
| US20240063747A1 (en) | Motor driving apparatus, motor system, and electric vehicle | |
| CN111969871A (en) | Rectification control method, system, equipment and computer readable storage medium | |
| JP3788346B2 (en) | Voltage type PWM inverter control device | |
| US20210083592A1 (en) | Voltage doubling variable frequency drive | |
| JP2003158880A (en) | Inverter device | |
| JPH0819259A (en) | Inverter circuit | |
| KR100335980B1 (en) | Apparatus and method for controlling of converter |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |