CN115313500A - Control method of four-quadrant power unit - Google Patents
Control method of four-quadrant power unit Download PDFInfo
- Publication number
- CN115313500A CN115313500A CN202211243618.1A CN202211243618A CN115313500A CN 115313500 A CN115313500 A CN 115313500A CN 202211243618 A CN202211243618 A CN 202211243618A CN 115313500 A CN115313500 A CN 115313500A
- Authority
- CN
- China
- Prior art keywords
- voltage
- direct
- axis
- power grid
- vector angle
- 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
- 238000000034 method Methods 0.000 title claims abstract description 25
- 239000013598 vector Substances 0.000 claims abstract description 68
- 230000002441 reversible effect Effects 0.000 claims abstract description 4
- 230000006641 stabilisation Effects 0.000 claims abstract description 4
- 238000011105 stabilization Methods 0.000 claims abstract description 4
- 230000001360 synchronised effect Effects 0.000 claims description 31
- 238000005070 sampling Methods 0.000 claims description 23
- 238000012937 correction Methods 0.000 claims description 18
- 238000006243 chemical reaction Methods 0.000 claims description 10
- 238000012545 processing Methods 0.000 claims description 10
- 230000003068 static effect Effects 0.000 claims description 4
- 230000009466 transformation Effects 0.000 claims description 4
- 238000004891 communication Methods 0.000 claims description 3
- 230000004907 flux Effects 0.000 claims description 3
- 238000010586 diagram Methods 0.000 description 4
- 238000010248 power generation Methods 0.000 description 3
- 230000033228 biological regulation Effects 0.000 description 2
- 239000003990 capacitor Substances 0.000 description 2
- 238000004804 winding Methods 0.000 description 2
- PMVSDNDAUGGCCE-TYYBGVCCSA-L Ferrous fumarate Chemical group [Fe+2].[O-]C(=O)\C=C\C([O-])=O PMVSDNDAUGGCCE-TYYBGVCCSA-L 0.000 description 1
- 230000001133 acceleration Effects 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 230000035772 mutation Effects 0.000 description 1
- 230000001052 transient effect Effects 0.000 description 1
Images
Classifications
-
- 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
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
- H02J3/381—Dispersed generators
-
- 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
- H02J3/24—Arrangements for preventing or reducing oscillations of power in networks
-
- 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
-
- 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
- H02J3/36—Arrangements for transfer of electric power between AC networks via a high-tension DC link
-
- 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
- H02M5/00—Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases
- H02M5/40—Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into DC
- H02M5/42—Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into DC by static converters
- H02M5/44—Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into DC by static converters using discharge tubes or semiconductor devices to convert the intermediate DC into AC
- H02M5/453—Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into DC by static converters using discharge tubes or semiconductor devices to convert the intermediate DC into AC using devices of a triode or transistor type requiring continuous application of a control signal
- H02M5/458—Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into DC by static converters using discharge tubes or semiconductor devices to convert the intermediate DC into AC using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P21/00—Arrangements or methods for the control of electric machines by vector control, e.g. by control of field orientation
- H02P21/14—Estimation or adaptation of machine parameters, e.g. flux, current or voltage
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P21/00—Arrangements or methods for the control of electric machines by vector control, e.g. by control of field orientation
- H02P21/22—Current control, e.g. using a current control loop
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P27/00—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage
- H02P27/04—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage
- H02P27/06—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage using DC to AC converters or inverters
- H02P27/08—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage using DC to AC converters or inverters with pulse width modulation
-
- 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
- H02J2203/00—Indexing scheme relating to details of circuit arrangements for AC mains or AC distribution networks
- H02J2203/20—Simulating, e g planning, reliability check, modelling or computer assisted design [CAD]
-
- 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
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
- Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Control Of Ac Motors In General (AREA)
Abstract
The invention discloses a control method of a four-quadrant power unit, wherein in an electric state, a PWM (pulse-Width modulation) rectifier module carries out PWM (pulse-Width modulation) on three-phase voltage of a power grid, an SVPWM vector angle of the PWM rectifier module dynamically lags behind a power grid vector angle, a power grid input power factor is close to 1, and a direct-current bus voltage is in a voltage stabilization state, so that active power factor compensation is completed, and forward flow of energy from the power grid to a motor is realized; under the feed state, when the inverter module and the motor operate in the braking state and the voltage of the direct current bus is increased, the SVPWM vector angle of the PWM rectifier module is adjusted to lead the SVPWM vector angle to be dynamically ahead of the vector angle of the power grid, the SVPWM rectifier module operates in the feedback state, the direct current of the bus is modulated into three-phase alternating current to be merged into the power grid, the voltage of the bus is stabilized, and the reverse flow of energy from the motor to the power grid is realized. The invention can stabilize the bus voltage in a safe area when the power unit works and keep the four-quadrant power unit to operate stably.
Description
Technical Field
The invention relates to a high-voltage frequency converter, in particular to a control method of a four-quadrant power unit.
Background
The cascade four-quadrant high-voltage frequency converter is key equipment of a variable-frequency driving system of a high-voltage motor, and is widely applied to energy-saving operation control and process speed regulation control of 10kV and 6kV high-voltage high-power motors. The cascade high-voltage frequency converter mainly comprises a phase-shifting transformer and 3N power units, wherein every N power units are connected in series to form a phase-change frequency-change voltage power supply, the 3N power units can form three single-phase frequency-change voltage power supplies, the three single-phase frequency-change voltage power supplies are connected into a star shape to form a three-phase output frequency-change voltage power supply, and the high-voltage output capacity is formed due to the cascade connection of the units and can be used for controlling the operation of a high-voltage motor.
When the four-quadrant power unit is in a motor power generation state, the over-high voltage of the unit bus is subjected to PWM rectification and fed back to a power grid through a phase-shifting transformer, so that the working stability of the four-quadrant frequency converter is kept.
When the four-quadrant power unit PWM rectifier module works in an electric state, active power factor adjustment is carried out on unit alternating current input, and the alternating current input power factor is close to 1.
Three-phase output of the high-voltage frequency converter is realized, each phase is formed by connecting a plurality of four-quadrant power units in series, three-phase imbalance can occur as long as load is carried, at the moment, the bus voltage of the three-phase units is possibly inconsistent, the input of the four-quadrant power units is from a phase-shifting transformer of a multi-output winding, the multi-output winding shares one iron core, and the unstable phenomenon of mutual interference can also occur; the bus voltage stability is an important guarantee for ensuring the operation stability and the operation safety, the output power is not up to the standard when the bus voltage is too low, the risk of explosion can be generated when the bus voltage is too high, and the severe fluctuation of the bus voltage can cause the unstable operation of the four-quadrant power unit.
Disclosure of Invention
The invention aims to provide a control method of a four-quadrant power unit, which can stabilize the bus voltage of the power unit in a safety interval.
In order to solve the technical problems, the technical scheme adopted by the invention is that the control method of the four-quadrant power unit comprises a PWM (pulse-width modulation) rectification module, an inversion module and a control circuit, wherein the PWM rectification module is provided with a three-phase alternating current input end and is connected with a three-phase alternating current power supply of a power grid to convert received alternating current into direct current; the inversion module is provided with an alternating current output end, is connected with the PWM rectification module through a direct current bus and is used for converting direct current into alternating current with adjustable frequency and driving a motor connected with the alternating current output end; the control circuit is respectively connected with the PWM rectification module and the inversion module and is used for controlling the PWM rectification module and the inversion module, and the control method comprises the following control steps:
101 Electrical state): the PWM rectifier module carries out PWM modulation on the three-phase voltage of the power grid, the SVPWM vector angle of the PWM rectifier module dynamically lags behind the vector angle of the power grid, the input power factor of the power grid is close to 1, the voltage of a direct-current bus is in a voltage stabilization state, active power factor compensation is completed, and forward flow of energy from the power grid to a motor is realized;
102 Power feeding state: when the inverter module and the motor operate in a braking state and the voltage of the direct-current bus rises, the SVPWM vector angle of the PWM rectification module is adjusted to lead the SVPWM vector angle to dynamically advance to the vector angle of the power grid, the SVPWM rectification module operates in a feedback state, the direct-current bus is modulated into three-phase alternating current to be merged into the power grid, the voltage of the bus is stabilized, and the reverse flow of energy from the motor to the power grid is realized.
The control method of the four-quadrant power unit comprises the following control steps:
201 The three-phase alternating-current voltage of the power grid is collected in real time, and a power grid vector angle is obtained through virtual flux linkage estimation;
202 The three-phase alternating current input into the PWM rectifier module is collected in real time, a controllable vector is obtained through alpha beta/dq conversion, and the direct-current bus voltage tends to be stable through a PI regulator;
203 Detecting the voltage of the direct current bus in real time, and comparing the sampling value of the voltage of the direct current bus with the set value of the direct current bus;
204 When the direct-current bus voltage is reduced to a set lower limit value, the vector angle of the PWM rectifier module is dynamically lagged behind the grid vector angle through space vector conversion, so that the direct-current bus voltage tends to be stabilized at the set lower limit value;
205 When the direct-current bus voltage rises to the set upper limit value, the vector angle of the PWM rectifier module is dynamically advanced from the grid vector angle through space vector conversion, so that the direct-current bus voltage tends to be stabilized at the set upper limit value.
The control method of the four-quadrant power unit comprises the following control steps:
the control circuit comprises a controller, a three-phase alternating current voltage sampling circuit, a three-phase alternating current sampling circuit and a direct current bus voltage sampling circuit, and comprises the following control steps:
301 The three-phase alternating voltage sampling signal is processed and decomposed into a grid voltage vector angle, a direct-axis voltage component of a d q synchronous rotating coordinate system and a quadrature-axis voltage component of the d q synchronous rotating coordinate system by a first signal processing unit;
302 The three-phase alternating current sampling signal is processed and decomposed into a direct-axis current component of a d q synchronous rotating coordinate system and a quadrature-axis current component of the d q synchronous rotating coordinate system by a second signal processing unit;
303 Power grid voltage vector angle is input to the phase-locked loop module, which outputs a phase-locked power grid voltage vector angle;
304 Carrying out difference operation and PI operation on the direct current bus voltage sampling value and a direct current bus voltage set value to obtain a direct-axis current reference and a quadrature-axis current reference of a dq synchronous rotation coordinate system;
305 Direct-axis current component id and direct-axis current reference are subjected to difference operation and PI operation to obtain a direct-axis voltage compensation value, and quadrature-axis current component iq and quadrature-axis current reference are subjected to difference operation and PI operation to obtain a quadrature-axis voltage compensation value;
306 Direct axis voltage component ud and direct axis voltage compensation value are summed to obtain direct axis voltage correction value, and quadrature axis voltage component uq and quadrature axis voltage compensation value are summed to obtain quadrature axis voltage correction value;
307 Phase-locked grid voltage vector angle theta o, direct axis voltage correction value and quadrature axis voltage correction value are respectively input into a synchronous rotating coordinate system inverse transformation module, and the direct axis voltage correction value and the quadrature axis voltage correction value are transformed into alpha beta stationary coordinate system data from data of a dq synchronous rotating coordinate system; outputting an alpha axis voltage component and a beta axis voltage component of an alpha beta static coordinate system;
308 The α -axis voltage component and the β -axis voltage component of the α β stationary coordinate system are input to the PWM data generation module, and a PWM drive signal for controlling the PWM rectification module is generated.
In the control method of the four-quadrant power unit, the controller is formed by combining the DSP, the MCu and the CPLD, and the DSP is used as a main control and is responsible for important data operation; the MCu is responsible for data acquisition and communication; the CPLD is responsible for the on-off of a PWM operation line, the quick linkage of fault protection, the logical processing of a switch and the expansion of an IO port.
The invention can stabilize the bus voltage in a safe area when the power unit works and keep the four-quadrant power unit to operate stably.
Drawings
The invention is described in further detail below with reference to the drawings and the detailed description.
Fig. 1 is a schematic block diagram of a main circuit of a four-quadrant power unit according to an embodiment of the present invention.
Fig. 2 is a control schematic diagram of a four-quadrant power unit according to an embodiment of the present invention.
Fig. 3 is a flowchart of a control method of a four-quadrant power unit according to an embodiment of the present invention.
FIG. 4 is a schematic diagram of a synchronous rotating coordinate system according to an embodiment of the present invention.
Fig. 5 is a diagram illustrating an operation effect of a biquad generalized integral PI phase-locked loop according to an embodiment of the present invention.
Detailed Description
The principle of the control method of the four-quadrant power unit of the embodiment of the invention is shown in fig. 1 to 5, the four-quadrant power unit comprises a PWM rectifier module (PWM three-phase IGBT rectifier bridge) 116, an inverter module 119 and a control circuit, the PWM rectifier module has a three-phase ac input end, and is connected with a three-phase ac power supply of a power grid 110 and an output end of a phase-shifting transformer through a reactor 117 to convert the received ac into dc; the inversion module is provided with an alternating current output end, is connected with the PWM rectification module through a direct current bus and is used for converting direct current into alternating current with adjustable frequency and driving a motor connected with the alternating current output end; a bus capacitor 118 is connected to the direct current bus; the control circuit is respectively connected with the PWM rectification module and the inversion module and is used for controlling the PWM rectification module and the inversion module. The PWM rectification module and the inversion module are communicated in a unit through a universal serial port at one time of 20mS, and after receiving the data, the inversion module refreshes the data of the PWM rectification module at a high speed according to a frame period of 30 microseconds and uploads the data to the control circuit.
The control method mainly comprises the following control steps:
1) Electric state: the PWM rectification module carries out PWM modulation on three-phase voltage of a power grid, an SVPWM vector angle of the PWM rectification module dynamically lags behind a power grid vector angle, a power grid input power factor is close to 1, the voltage of a direct-current bus is in a voltage stabilization state, active power factor compensation is completed, and forward flow of energy from the power grid to a motor is realized;
2) And (3) a power feeding state: when the inverter module and the motor operate in a braking state and the voltage of the direct-current bus is increased, the SVPWM vector angle of the PWM rectifier module is adjusted to dynamically lead the SVPWM vector angle to the vector angle of the power grid, the SVPWM rectifier module operates in a feedback state, the bus direct-current is modulated into three-phase alternating current to be merged into the power grid, the voltage of the bus is stabilized, and the reverse flow of energy from the motor to the power grid is realized.
The flow of the four-quadrant power unit control method of the embodiment of the invention is shown in fig. 3, and the method comprises the following control steps:
1) In steps 316 and 317, collecting the three-phase alternating-current voltage of the power grid in real time, and estimating through a virtual flux linkage to obtain a power grid vector angle; the operation process comprises a power grid phase-locked loop, a stable power grid phase is provided, and the phase-locked loop can be kept stable even if the power grid voltage fluctuates severely;
2) If in steps 318, 319 and 320, the three-phase alternating current input to the PWM rectifier module is collected in real time from between the reactor and the PWM rectifier module, a controllable vector is obtained through α β/dq conversion, and the direct-current bus voltage tends to be stable through the PI regulator;
3) Detecting the voltage of the direct current bus in real time and comparing the sampling value of the voltage of the direct current bus with the set value of the direct current bus as in steps 307, 304, 305, 309 and 310;
4) In the electric state of the motor, the voltage of the bus is reduced less when the motor is in light load, and the voltage of the direct current bus can be reduced to a 6-pulse rectification baseline when the motor is in heavy load; when the dc bus voltage drops to the set lower limit 970V in steps 306 and 312, dynamically lagging the vector angle of the PWM rectifier module to the grid vector angle through space vector conversion and PI regulator, so that the dc bus voltage tends to be stabilized at the set lower limit 970V and the current of the grid tends to be stabilized;
5) Under the power generation state of the motor, when the motor is in the running states of deceleration, galloping or restarting and the like, the energy of the motor can reversely flow, and the generated electric energy charges a bus capacitor through an inversion module; when the dc bus voltage rises to the set upper limit value 1150V, the vector angle of the PWM rectifier module is dynamically advanced from the grid vector angle by the space vector conversion and the PI regulator, so that the dc bus voltage tends to be stabilized at the set upper limit value 1150V and the current of the grid tends to be stabilized, as shown in steps 311 and 312.
The control principle of the four-quadrant power unit in the embodiment of the invention is shown in fig. 2:
the control circuit comprises a controller, a three-phase alternating current voltage sampling circuit, a three-phase alternating current sampling circuit and a direct current bus voltage sampling circuit, and comprises the following control steps:
1) Three-phase alternating voltages ua, ub and uc output by the phase-shifting transformer are calculated by a first signal processing unit 111 through sampling signals obtained by a three-phase alternating voltage sampling circuit, and a direct-axis voltage component ud of a grid voltage vector angle theta and a d q synchronous rotation coordinate system and a quadrature-axis voltage component uq of the d q synchronous rotation coordinate system are decomposed;
2) The three-phase alternating current sampling circuit samples the currents ia, ib and ic between the reactor 117 and the PWM rectification module 116, and the three-phase alternating current sampling signal is processed by the second signal processing unit 112 to decompose the direct-axis current component id of the d q synchronous rotation coordinate system and the quadrature-axis current component iq of the d q synchronous rotation coordinate system; the direct-axis voltage component ud, the quadrature-axis voltage component uq, the direct-axis current component id and the quadrature-axis current component iq are controllable vectors, and the next operation is facilitated;
3) The grid voltage vector angle theta is input into a phase-locked loop module, and the phase-locked loop module outputs a phase-locked grid voltage vector angle theta o;
4) Performing difference operation and PI operation on a direct current bus voltage sampling value Vdc and a direct current bus voltage set value (Vdc set) to obtain a direct-axis current reference (id _ reference) and a quadrature-axis current reference (iq _ reference) of a d q synchronous rotation coordinate system;
5) The direct-axis current component id and a direct-axis current reference (id _ reference) are subjected to difference operation and PI operation to obtain a direct-axis voltage compensation value, and the quadrature-axis current component iq and a quadrature-axis current reference (iq _ reference) are subjected to difference operation and PI operation to obtain a quadrature-axis voltage compensation value;
6) Summing the direct axis voltage component ud and the direct axis voltage compensation value to obtain a direct axis voltage correction value, and summing the quadrature axis voltage component uq and the quadrature axis voltage compensation value to obtain a quadrature axis voltage correction value;
7) The phase-locked grid voltage vector angle theta o, the direct axis voltage correction value and the quadrature axis voltage correction value are respectively input into the synchronous rotating coordinate system inverse transformation module 114, and the direct axis voltage correction value and the quadrature axis voltage correction value are transformed into alpha beta static coordinate system data by data of a dq synchronous rotating coordinate system; outputting an alpha axis voltage component and a beta axis voltage component of an alpha beta static coordinate system;
8) The α -axis voltage component and the β -axis voltage component of the α β stationary coordinate system are input to the PWM data generation module 115, and PWM drive signals for controlling the PWM rectification module 116 are generated.
The control method of the above embodiment of the invention makes the bus voltage and the power grid current tend to be stable through PI regulation; the PI regulator dynamically leads or lags the vector angle of the PWM rectification in the power grid vector angle, so that the bus voltage is stabilized near a target voltage value, and the power grid working current tends to be stable regardless of the electric state or the power generation state.
The controller is formed by combining a DSP, an MCu and a CPLD, and the DSP is used as a master control and is responsible for important data operation; the MCu is responsible for data acquisition and communication; the CPLD is responsible for the on-off of a PWM operation line, the quick linkage of fault protection, the logical processing of a switch and the expansion of an IO port.
The phase-locked loop module is a biquad PI phase-locked loop based on software and hardware combination, namely the phase-locked loop module is based on a synchronous rotating coordinate system and a second-order generalized integral PI phase-locked loop and can accurately acquire frequency and phase information of a positive sequence component of power grid voltage under the conditions of unbalanced power grid voltage, voltage drop, frequency mutation or multiple harmonics.
The phase-locked loop satisfies the following formula conditions:
when the angle theta = theta 2= theta o, the angular frequency omega 1= omega 2, the phase difference phi err =0, the rotation coordinate direct axis ud = u, and the rotation coordinate quadrature axis uq =0, the phase locking is successful.
Wherein,
u α is the α -axis voltage component of the α β stationary frame;
u β is a β -axis voltage component of the α β stationary coordinate system; ud is the direct axis voltage component of the dq synchronous rotating coordinate system;
uq is the quadrature axis voltage component of the dq synchronous rotation coordinate system;
theta is an input grid voltage vector angle theta;
theta 2 is a vector angle of the software synchronous rotation coordinate system, namely an initial angle of the dq synchronous rotation coordinate system; θ o is the grid voltage vector angle of the phase lock;
ω 1 is the grid angular frequency;
omega 2 is the angular frequency of the software synchronous rotating coordinate system; and omega 2 is the angular frequency obtained by the DSP arctangent correlation software module calculating the angle theta 2 of the alpha beta software synchronous rotation coordinate system and the angle passed by the DSP arctangent correlation software module in unit time. ω 2 is made to approach or equal ω 1 by adjusting Φ err.
Φ err is an angle error of an input grid voltage vector angle θ and a synchronous rotation coordinate system vector angle input grid voltage vector angle θ 2;
u is the phase voltage of the power grid, is converted into ua, ub and uc in the operation process, then is converted into u alpha and u beta, and then is converted into ud and uq; namely, three variables of three-phase voltage are finally converted into two variables which are easy to operate.
As shown in fig. 4, in the phase-locked loop dq synchronous rotation coordinate system, the vector angle between the direct-axis component and the quadrature-axis component is θ o, which is the vector angle output after three-phase alternating current phase locking; transformation into d-axis and q-axis components by a formula may facilitate computation and processing;
d expresses the magnitude of voltage, the larger d expresses the larger the counter electromotive force, the more the output device and the target equipment reach energy balance at the moment, and the output force is mutually counteracted at the moment; otherwise, the state deviates from the equilibrium state; q expresses the magnitude of the force generally expressed as uq/iq; the q value is positive acting force, and the q value is negative positive acting force; the larger the q value is, the larger the d value is, the smaller the d value is, and the acceleration or deceleration state is entered, otherwise, the equilibrium state is entered.
As shown in fig. 5, when the grid voltage is switched to a bad working condition under a stable working condition, the phase-locked energy loop keeps stable, so that the waveform of the output PWM rectification voltage keeps stable, and the three-phase PWM rectification current is balanced and stable. In the context of figure 5, it is shown,
201, intput uabc is the input grid voltage waveform;
202: ud and uq are the sizes of the synchronously rotating coordinate system ud, uq on the time axis;
203: outputting a monitored vector angle theta o time axis;
204: Φ err is the phase-lock error time axis;
205: ontputuabc is the voltage waveform output to the grid.
The control method of the four-quadrant power unit in the above embodiment of the invention achieves balance in dynamic conversion of stability and transient response through the biquad generalized integral PI phase-locked loop combining software and hardware, so that the bus voltage is stabilized between an upper limit and a lower limit, and quick response can be realized, thereby maintaining safe operation of the four-quadrant power unit.
Claims (4)
1. A control method of a four-quadrant power unit comprises a PWM (pulse-width modulation) rectification module, an inversion module and a control circuit, wherein the PWM rectification module is provided with a three-phase alternating current input end and is connected with a three-phase alternating current power supply of a power grid to convert received alternating current into direct current; the inversion module is provided with an alternating current output end, is connected with the PWM rectification module through a direct current bus and is used for converting direct current into alternating current with adjustable frequency and driving a motor connected with the alternating current output end; the control circuit is respectively connected with the PWM rectification module and the inversion module and used for controlling the PWM rectification module and the inversion module, and the control circuit is characterized by comprising the following control steps:
101 Electrical state): the PWM rectification module carries out PWM modulation on three-phase voltage of a power grid, an SVPWM vector angle of the PWM rectification module dynamically lags behind a power grid vector angle, a power grid input power factor is close to 1, the voltage of a direct-current bus is in a voltage stabilization state, active power factor compensation is completed, and forward flow of energy from the power grid to a motor is realized;
102 Power feeding state: when the inverter module and the motor operate in a braking state and the voltage of the direct-current bus rises, the SVPWM vector angle of the PWM rectification module is adjusted to lead the SVPWM vector angle to dynamically advance to the vector angle of the power grid, the SVPWM rectification module operates in a feedback state, the direct-current bus is modulated into three-phase alternating current to be merged into the power grid, the voltage of the bus is stabilized, and the reverse flow of energy from the motor to the power grid is realized.
2. The control method of the four-quadrant power unit according to claim 1, characterized by comprising the following control steps:
201 Three-phase alternating current voltage of a power grid is collected in real time, and a power grid vector angle is obtained through virtual flux linkage estimation;
202 The method comprises the steps of) collecting three-phase alternating current input into a PWM rectification module in real time, obtaining a controllable vector through alpha beta/dq conversion, and enabling the direct-current bus voltage to tend to be stable through a PI regulator;
203 Detecting the voltage of the direct current bus in real time, and comparing the sampling value of the voltage of the direct current bus with the set value of the direct current bus;
204 When the direct-current bus voltage is reduced to a set lower limit value, the vector angle of the PWM rectifier module is dynamically lagged behind the vector angle of the power grid through space vector conversion, so that the direct-current bus voltage tends to be stabilized at the set lower limit value;
205 When the direct-current bus voltage rises to the set upper limit value, the vector angle of the PWM rectifier module is dynamically advanced from the grid vector angle through space vector conversion, so that the direct-current bus voltage tends to be stabilized at the set upper limit value.
3. The method of controlling a four-quadrant power unit according to claim 1, wherein the control circuit includes a controller, a three-phase ac voltage sampling circuit, a three-phase ac current sampling circuit, and a dc bus voltage sampling circuit, and includes the steps of:
301 The three-phase alternating voltage sampling signal is processed and decomposed into a grid voltage vector angle, a direct-axis voltage component of a d q synchronous rotating coordinate system and a quadrature-axis voltage component of the d q synchronous rotating coordinate system by a first signal processing unit;
302 The three-phase alternating current sampling signal is processed and decomposed by a second signal processing unit to obtain a direct-axis current component of a d q synchronous rotating coordinate system and a quadrature-axis current component of the d q synchronous rotating coordinate system;
303 Power grid voltage vector angle is input to the phase-locked loop module, which outputs a phase-locked power grid voltage vector angle;
304 Carrying out difference operation and PI operation on the direct current bus voltage sampling value and a direct current bus voltage set value to obtain a direct-axis current reference and a quadrature-axis current reference of a dq synchronous rotation coordinate system;
305 Direct-axis current component id and direct-axis current reference are subjected to difference operation and PI operation to obtain a direct-axis voltage compensation value, and quadrature-axis current component iq and quadrature-axis current reference are subjected to difference operation and PI operation to obtain a quadrature-axis voltage compensation value;
306 Direct-axis voltage component ud and the direct-axis voltage compensation value are summed to obtain a direct-axis voltage correction value, and quadrature-axis voltage component uq and the quadrature-axis voltage compensation value are summed to obtain a quadrature-axis voltage correction value;
307 Phase-locked grid voltage vector angle theta o, direct axis voltage correction value and quadrature axis voltage correction value are respectively input into a synchronous rotating coordinate system inverse transformation module, and the direct axis voltage correction value and the quadrature axis voltage correction value are transformed into alpha beta stationary coordinate system data from data of a dq synchronous rotating coordinate system; outputting an alpha axis voltage component and a beta axis voltage component of an alpha beta static coordinate system;
308 The α -axis voltage component and the β -axis voltage component of the α β stationary coordinate system are input to the PWM data generation module, and a PWM drive signal for controlling the PWM rectification module is generated.
4. The method for controlling the four-quadrant power unit according to claim 3, wherein the controller is composed of a combination of a DSP, an MCu and a CPLD, and the DSP is used as a master control and is responsible for important data operation; the MCu is responsible for data acquisition and communication; the CPLD is responsible for switching on and off of a PWM operation line, quick linkage of fault protection, switch logic processing and IO port expansion.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211243618.1A CN115313500B (en) | 2022-10-12 | 2022-10-12 | Control method of four-quadrant power unit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211243618.1A CN115313500B (en) | 2022-10-12 | 2022-10-12 | Control method of four-quadrant power unit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115313500A true CN115313500A (en) | 2022-11-08 |
| CN115313500B CN115313500B (en) | 2023-08-04 |
Family
ID=83868000
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211243618.1A Active CN115313500B (en) | 2022-10-12 | 2022-10-12 | Control method of four-quadrant power unit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115313500B (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101425756A (en) * | 2008-07-30 | 2009-05-06 | 东元总合科技（杭州）有限公司 | DC lateral voltage controllable 4 quadrant frequency transformer and method thereof |
| US20130016546A1 (en) * | 2011-06-24 | 2013-01-17 | Rolls-Royce Plc | Electrical system architecture and electrical power generation system |
| CN102916597A (en) * | 2012-10-26 | 2013-02-06 | 河南师范大学 | PWM (pulse width modulation) rectifier input and output power compensation control method in voltage asymmetry |
| CN103023057A (en) * | 2012-10-26 | 2013-04-03 | 河南师范大学 | Voltage-type PWM (pulse-width modulation) rectifier output power control method under power grid unsymmetrical fault |
| CN103051281A (en) * | 2013-01-30 | 2013-04-17 | 秦皇岛国能石油装备有限公司 | High-performance four-quadrant frequency converter |
-
2022
- 2022-10-12 CN CN202211243618.1A patent/CN115313500B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101425756A (en) * | 2008-07-30 | 2009-05-06 | 东元总合科技（杭州）有限公司 | DC lateral voltage controllable 4 quadrant frequency transformer and method thereof |
| US20130016546A1 (en) * | 2011-06-24 | 2013-01-17 | Rolls-Royce Plc | Electrical system architecture and electrical power generation system |
| CN102916597A (en) * | 2012-10-26 | 2013-02-06 | 河南师范大学 | PWM (pulse width modulation) rectifier input and output power compensation control method in voltage asymmetry |
| CN103023057A (en) * | 2012-10-26 | 2013-04-03 | 河南师范大学 | Voltage-type PWM (pulse-width modulation) rectifier output power control method under power grid unsymmetrical fault |
| CN103051281A (en) * | 2013-01-30 | 2013-04-17 | 秦皇岛国能石油装备有限公司 | High-performance four-quadrant frequency converter |
Non-Patent Citations (2)
| Title |
|---|
| 王恩德: "四象限变频器在电机控制中的应用研究_", 《中国优秀硕士学位论文全文数据库》 * |
| 王恩德: "四象限变频器在电机控制中的应用研究_", 《中国优秀硕士学位论文全文数据库》, no. 2, 15 February 2014 (2014-02-15), pages 1 - 106 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115313500B (en) | 2023-08-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104242775B (en) | The open winding permanent magnet synchronous motor system zero-sequence current suppressing method that twin inverter is powered | |
| EP3796538B1 (en) | Capacitor size reduction and lifetime extension for cascaded h-bridge drives | |
| Zuo et al. | Current sensor fault-tolerant control for speed-sensorless induction motor drives based on the SEPLL current reconstruction scheme | |
| Foti et al. | Asymmetrical hybrid unidirectional T-type rectifier for high-speed gen-set applications | |
| Rezaei et al. | Modelling and analysis of indirect field-oriented control of SVPWM-driven induction motor drive based on a voltage source inverter | |
| Liu et al. | A novel switching-table-based direct torque control with improved current and torque steady-state performance for dual three-phase PMSM | |
| Bojoi et al. | Frequency-domain analysis of resonant current controllers for active power conditioners | |
| CN116054233A (en) | Switching control method of grid-structured inverter with phase supporting capability under fault | |
| Ryu et al. | A dead time compensation method in voltage-fed PWM inverter | |
| WO2013007107A1 (en) | Variable frequency speed control system for motor | |
| Zhu et al. | Grid synchronization control without AC voltage sensors | |
| CN115313500B (en) | Control method of four-quadrant power unit | |
| Zhang et al. | Direct-Axis Current Orientation Based Grid Voltage Sensorless Control Strategy for Vienna Rectifier Under Unbalanced and Distorted Grid Conditions | |
| Thapa et al. | Torque ripple reduction in a traction ipmsm with resistance asymmetry using an adaptive pir current controller | |
| Zhang et al. | Closed-loop control of PMSM based on optimal synchronous pulse patterns | |
| Moussa et al. | Robust WTE sensorless design based on soft-VSI structure for three-phase IM drive using sliding mode observer controller | |
| CN102468652B (en) | Reactive power control system and control method thereof | |
| EP3745587A2 (en) | Power conversion device and variable-speed pumped-storage power generation system | |
| JP2000287457A (en) | Voltage source self-excited power converter | |
| Kwon et al. | Three-phase PWM synchronous rectifiers without line-voltage sensors | |
| Li et al. | Multi-virtual-vector-based predictive current control for fault-tolerant inverter-fed dual three-phase permanent magnet synchronous machines | |
| Hu et al. | Improved MRAS observer and sensorless control of DFIG during network voltage unbalance | |
| CN117424478B (en) | Three-phase four-bridge arm inverter control system and control method of composite repetitive controller | |
| Misra et al. | Single current sensor based vector control of AC/DC front end converter | |
| Huang et al. | Fault-tolerant stator flux oriented decoupling control for dual three-phase permanent magnet motor without diagnosis and reconfiguration |
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 |