CN115149884A - Boost three-phase electric driver and fault-tolerant control method thereof - Google Patents

Boost three-phase electric driver and fault-tolerant control method thereof Download PDF

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CN115149884A
CN115149884A CN202211075441.9A CN202211075441A CN115149884A CN 115149884 A CN115149884 A CN 115149884A CN 202211075441 A CN202211075441 A CN 202211075441A CN 115149884 A CN115149884 A CN 115149884A
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fault
vector
voltage
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CN115149884B (en
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冯延晖
孔繁伟
邱颖宁
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Nanjing University of Science and Technology
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    • 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
    • H02P29/00—Arrangements for regulating or controlling electric motors, appropriate for both AC and DC motors
    • H02P29/02—Providing protection against overload without automatic interruption of supply
    • H02P29/024—Detecting a fault condition, e.g. short circuit, locked rotor, open circuit or loss of load
    • H02P29/028—Detecting a fault condition, e.g. short circuit, locked rotor, open circuit or loss of load the motor continuing operation despite the fault condition, e.g. eliminating, compensating for or remedying the fault
    • 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
    • H02P21/0003—Control strategies in general, e.g. linear type, e.g. P, PI, PID, using robust control
    • 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
    • H02P25/00—Arrangements or methods for the control of AC motors characterised by the kind of AC motor or by structural details
    • H02P25/16—Arrangements or methods for the control of AC motors characterised by the kind of AC motor or by structural details characterised by the circuit arrangement or by the kind of wiring
    • 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
    • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
    • H02P2205/00—Indexing scheme relating to controlling arrangements characterised by the control loops
    • H02P2205/01—Current loop, i.e. comparison of the motor current with a current reference
    • 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
    • H02P2205/00—Indexing scheme relating to controlling arrangements characterised by the control loops
    • H02P2205/07—Speed loop, i.e. comparison of the motor speed with a speed reference

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Control Of Ac Motors In General (AREA)

Abstract

The invention discloses a boost three-phase electric driver and a fault-tolerant control method thereof.A corresponding topological structure and a control algorithm are adjusted according to the running condition of a system, and a boost three-phase six-switch topology is switched into a boost three-phase four-switch topology after a fault occurs; the original double-loop control of a rotating speed loop and a current loop is switched into three-loop control of a voltage loop, a rotating speed loop and a current loop; reconstructing a basic voltage vector under the condition of single tube or single-phase fault; dividing the sectors by adopting a 4-sector division mode; selecting an action vector from the reconstructed basic voltage vector, and determining a corresponding action time; determining the conduction time of each switching tube after the step-up three-phase electric driver reconstructs topology; and modulating the conduction time of the switching tube with a triangular carrier, and outputting a PWM pulse signal of the switching tube to finish fault-tolerant control. The invention can realize the fault-tolerant operation with high power quality and full load and improve the reliability of the boost type electric driver.

Description

Boost three-phase electric driver and fault-tolerant control method thereof
Technical Field
The invention belongs to the technical field of electric drive control, and particularly relates to a boost type three-phase electric drive and a fault-tolerant control method thereof.
Background
Some energy storage or power generation devices, such as energy storage cells, fuel cells, photovoltaic power generation devices, and the like, are constructed using low voltage batteries. To obtain higher voltages, one approach is to connect in series to obtain the required voltage. The series connection of a large number of cells will increase the complexity of the system and may reduce its performance due to differences between cells and different operating conditions. Another approach is to use a DC-DC boost converter between the DC source and the driver and then invert it to ac for practical use. Such systems requiring additional boost circuitry are referred to as two-stage drivers. Depending on the power and voltage levels involved, the use of a two-stage driver presents problems of large system size, heavy weight, high cost, and reduced efficiency.
A single stage DC-AC driver with boost capability is a good alternative to a two stage driver in terms of size, cost, weight and overall system complexity. In the case of high-load and overload operation, the power switch tube is the weakest part in the converter, and the investigation shows that the fault rate of the switch tube in the converter system reaches 38%. In order to avoid major accidents and reduce the downtime, the performance before the fault is recovered as much as possible, and the boost three-phase electric drive system must be subjected to fault-tolerant control.
The conventional single-stage three-phase inverter with a voltage boosting and reducing function mainly comprises a Z-source inverter (ZSI), a voltage reduction-boosting voltage source inverter (BBVSI), a Y-source inverter (YSI) and a split-source inverter (SSI). SSI has additional advantages over these topologies. SSI uses only diodes compared to BBVSI using additional active semiconductor switches; it reduces the number of passive components compared to ZSI and YSI. The voltage across the bridge of the SSI is constant and control is achieved using the same modulation scheme as a conventional three-phase Voltage Source Inverter (VSI). The Three-Phase Split-Source Inverter (SSI): analysis and Modulation "analyzes the operation mode and Modulation method of the Split-Source Inverter SSI. However, no fault-tolerant technology aiming at solving the three-phase six-switch split-source inverter is researched at present.
Disclosure of Invention
The invention aims to provide a boost three-phase electric driver and a fault-tolerant control method thereof.
The technical solution for realizing the purpose of the invention is as follows: a step-up three-phase electric driver has two serially connected capacitors C on its DC side f The middle points of the two capacitors are respectively connected to a winding end of a three-phase a, a winding end of a three-phase b and a winding end of a three-phase c through 3 bidirectional thyristors TR1, TR2 and TR3, and the other ends of the series capacitors are respectively connected with a phase a, a phase b and a phase c of a three-phase bridge arm; power supply U In The negative pole of the lower bridge arm is connected with the a phase, the b phase and the c phase of the three-phase bridge arm, the positive pole of the lower bridge arm is connected with an inductor L1, the other end of the inductor L1 is connected with the positive poles of diodes D7, D8 and D9, and the negative poles of the diodes D7, D8 and D9 are respectively connected with the a, b and c three-phase winding ends; the three-phase bridge arm phase a, the phase b and the phase c are composed of six IGBT power switching tubes S1-S6 and six diodes D1-D6 connected with the switching tubes in parallel, each phase of bridge arm is connected with 2 fast fuses in series, and 6 fast fuses F1-F6 are provided; when a power device of a certain bridge arm of the driver has a short-circuit fault, the corresponding fast fuse is fused, and the fault bridge arm is disconnected; when open-circuit fault occurs, the fault bridge arm automatically fails, the input of a driving signal of a switching tube of the fault bridge arm is stopped, a corresponding bidirectional thyristor is turned on simultaneously, and the switching system is in a boost three-phase four-switch topological structure.
Further, a rotating speed outer ring and a current inner ring are adopted to operate in a double closed loop mode, wherein the rotating speed ring acquires the rotating speed of the motor, the rotating speed is differed from a reference rotating speed and is input into a PI (proportional-integral) regulator, and a q-axis current reference value is output; the current loop collects three-phase current and the electrical angle of the motor, and d is obtained through Park conversion
Figure 893276DEST_PATH_IMAGE001
q-axis current, respectively subtracting the reference values of d-axis current and q-axis current, inputting the difference into a PI regulator, outputting the reference values of d-axis voltage and q-axis voltage, and obtaining alpha-axis voltage reference values and beta-axis voltage reference values through Park inverse transformation
Figure 810417DEST_PATH_IMAGE002
Inputting the signals into an SVPWM control module to generate 6 paths of signals for controlling the on-off of the IGBT gate pole;
and during fault-tolerant operation, a voltage and rotating speed outer ring and a current inner ring are adopted for three closed-loop operation, wherein the rotating speed ring and the current ring are consistent with normal operation, the voltage reference value in the voltage ring is twice of the direct-current side capacitor voltage during normal operation, the difference is made between the voltage reference value and the collected direct-current side capacitor voltage, the voltage reference value is input into a PI regulator, an intermediate variable Tz is output and input into an SVPWM module, and the PI module continuously adjusts the value of the Tz until the direct-current side capacitor voltage Udc is raised to twice of the original value, so that fault-tolerant control is completed.
A fault-tolerant control method for a boost three-phase electric driver is used for completing fault-tolerant control based on the boost three-phase electric driver and comprises the following steps:
step 1, establishing a basic voltage vector under the condition of no fault;
step 2, switching the topological structure of the boost three-phase electric driver according to the position of the fault switching tube;
step 3, reconstructing a basic voltage vector under the condition of single tube or single-phase fault;
step 4, a 4-sector division mode is adopted to divide the sectors;
step 5, selecting action vectors from the reconstructed basic voltage vectors, and determining corresponding action time;
step 6, determining the conduction time of each switching tube after the step-up three-phase electric driver reconstructs topology;
and 7, modulating the conduction time of the switching tube with a triangular carrier, and outputting a PWM pulse signal of the switching tube to finish fault-tolerant control.
Further, step 1, establishing a basic voltage vector under a fault-free condition, as shown in table 1:
TABLE 1 Fault-free basic Voltage vector Table
Figure 216253DEST_PATH_IMAGE004
Wherein (Sa Sb Sc) is a switching function of a phase bridge arm, b phase bridge arm and c phase bridge arm, a function value of "1" indicates that the switch tube of the upper bridge arm of the phase is conducted, a function value of "0" indicates that the switch tube of the lower bridge arm of the phase is conducted, different switch state combinations of the switch tubes respectively correspond to 8 basic voltage vectors, which are respectively: u0 (000), U1 (100), U2 (110), U3 (010), U4 (011), U5 (001), U6 (101) and U7 (111), wherein Ua, ub and Uc in the table are three-phase voltage of a three-phase driver, uk is a basic voltage vector obtained by Clark conversion of three-phase voltages of a, b and c, k is 0 to 7, and udc is direct-current side capacitance voltage.
Further, step 2, according to the position of the fault switching tube, switching the topology structure of the boost three-phase electric driver, the specific method is as follows:
when the phase a fails, the boost type three-phase electric driver is controlled by the four switching tubes of the phase b and the phase c, when the phase b fails, the boost type three-phase electric driver is controlled by the four switching tubes of the phase c and the phase a, and when the phase c fails, the boost type three-phase electric driver is controlled by the four switching tubes of the phase a and the phase b, and because the faults include an open-circuit fault and a short-circuit fault, the action of the bidirectional thyristor corresponding to the open-circuit fault is shown in table 2:
TABLE 2 bidirectional thyristor action corresponding to different switching tube open-circuit faults
Figure 611462DEST_PATH_IMAGE006
When the switching tube has a short-circuit fault, the corresponding fast fuse of the switching tube is fused, the short-circuit fault is converted into an open-circuit fault, and the action of the bidirectional thyristor and the fast fuse corresponding to the short-circuit fault is shown in table 3;
TABLE 3 bidirectional thyristor corresponding to different switch tube short-circuit faults and quick fuse action
Figure 550468DEST_PATH_IMAGE007
Further, step 3, reconstructing a basic voltage vector under the condition of single tube or single-phase fault, wherein the specific method comprises the following steps:
determining the relation between the motor phase voltage and the switch state:
Figure 372930DEST_PATH_IMAGE008
in the formula, ua, ub and Uc are three-phase voltages of a three-phase driver, sa, sb and Sc respectively represent the switching states of power devices on bridge arms a, b and c, when the switching states are equal to '1', an upper tube is switched on, a lower tube is switched off, and when the switching states are equal to '0', the upper tube is switched on, and the upper tube is switched off; when the phase a fails, the motor winding phase a is connected to the middle point of the capacitor, and Sa is constant 1/2; the boost three-phase electric driver is controlled by four switching tubes of b and c phases and has 4 switching states of (Sb Sc) = (0), (Sb Sc) = (1) and (Sb Sc) = (1); when a phase b fails, the motor winding b is connected to the middle point of a capacitor, sb is constantly 1/2, the boost three-phase electric driver is controlled by four switching tubes of phases c and a, and has 4 switching states of (Sc Sa) = (0), (Sc Sa) = (1); when the c phase fails, the motor winding c is connected to the middle point of the capacitor, sc is constant to 1/2, the boost three-phase electric driver is controlled by four switching tubes of the a phase and the b phase, and has 4 switching states of (SaSb) = (0), (SaSb) = (1);
determining a three-phase composite voltage space vector:
Figure 266062DEST_PATH_IMAGE009
in the formula
Figure 464962DEST_PATH_IMAGE010
Is a spatial rotation factor;
determining a basic voltage vector under the condition of reconstructing a single tube or single-phase fault, as shown in table 4;
table 4 reconstructed basic voltage vector table
Figure 258475DEST_PATH_IMAGE012
After a fault occurs to one of the three phases a, b and c, the four basic voltage vectors of U0', U1', U2 'and U3' are sequenced in a plane according to the clockwise sequence of U0', U1', U3 'and U2', each adjacent vector is separated by 90 degrees, and in order to simplify the calculation of the reference vector after the fault of each phase, the coordinate axes are unified
Figure 251839DEST_PATH_IMAGE013
’、
Figure 632267DEST_PATH_IMAGE014
The positive direction is the positive direction of the basic voltage vectors U0 'and U2', and the reference vector
Figure 369279DEST_PATH_IMAGE015
In that
Figure 17298DEST_PATH_IMAGE013
’、
Figure 447142DEST_PATH_IMAGE014
' projection on axis of
Figure 314866DEST_PATH_IMAGE016
、
Figure 589990DEST_PATH_IMAGE017
。
Further, in step 4, a four-sector division mode is adopted to divide the sectors, and the specific method is as follows:
defining a function:
Figure 233461DEST_PATH_IMAGE018
；
Figure 693261DEST_PATH_IMAGE019
defining sector calculation value N:
Figure 422182DEST_PATH_IMAGE020
determining the corresponding relation between the N and the actual sector number through the table 5 to complete sector division;
table 5 correspondence table between calculated value and sector of 5N
Figure 127095DEST_PATH_IMAGE022
Further, step 5, selecting an action vector from the reconstructed basic voltage vector, and determining a corresponding action time, wherein the specific method comprises the following steps:
step 5.1, selecting action vectors from the reconstructed basic voltage vectors;
the action vector comprises an effective vector and a zero vector, the basic voltage vectors U0 '-U3' are independently used as the effective vector, the two basic voltage vectors in opposite directions are taken to synthesize an equivalent zero vector, namely, an equivalent zero vector is synthesized by using U0 '(00) and U3' (11), and the other equivalent zero vector is synthesized by using U1 '(01) and U2' (10); synthesizing the effective vector and the equivalent zero vector into a reference vector;
considering the minimum switching loss, when the reference vector is positioned in the first sector, selecting the basic voltage vectors to act in the sequence of U2', U0', U1 'and U3'; when the reference vector is positioned in a second sector, selecting the basic voltage vectors to act in the sequence of U3', U2', U0 'and U1'; when the reference vector is positioned in the third sector, selecting the basic voltage vectors with the action sequence of U1', U3', U2 'and U0'; when the reference vector is positioned in the fourth sector, selecting the basic voltage vectors as U0', U1', U3 'and U2';
step 5.2, determining the action time of the action vector;
defining the intermediate variables:
Figure 625073DEST_PATH_IMAGE023
wherein Ts is a switching period;
setting effective vectors acted by the first sector as U0 'and U2', and respectively setting action time as Tx and Ty; effective vectors acted by the second sector are U2 'and U3', and action time is Tx and Ty respectively; the effective vectors acted by the third sector are U3 'and U1', and the acting time is Tx and Ty respectively; the effective vectors acted by the fourth sector are U1 'and U0', and the action time is Tx and Ty respectively; determining the action time of the effective vector of each sector through a table 6;
TABLE 6 Effect time of the effective vector of each sector
Figure 521354DEST_PATH_IMAGE025
Defining the action time of the equivalent zero vector:
T0=Ts-Tx-Ty
since the equivalent zero vector of each sector is jointly synthesized by U0', U1', U2', U3', the intermediate variables are defined:
0<=Tz<=T0
the action time of two basic voltage vectors synthesizing equivalent zero vector is equal, then the action time of U1 'and U2' is
Figure 471992DEST_PATH_IMAGE026
、
Figure 980596DEST_PATH_IMAGE026
(ii) a The action time of U0 'and U3' is
Figure 333080DEST_PATH_IMAGE027
、
Figure 400262DEST_PATH_IMAGE027
；
The base voltage vector action time for each sector is determined by table 7:
TABLE 7 fundamental Voltage vector action time for each sector
Figure 838197DEST_PATH_IMAGE028
。
Further, in step 6, determining the conduction time of each switching tube after the step-up three-phase electric driver reconstructs the topology, and the specific method is as follows:
table 8 switching time points of each switching tube after topology reconstruction
Figure 884912DEST_PATH_IMAGE029
In a switching period, determining the switching time point of each switching tube after the topology is reconstructed through a table 8, wherein in the table, the values of M, N are all a, b and c, and when M = a, b and c, corresponding N = b, c and a;
5363 the on and off time points of a phase M, N represent the on and off times of the upper switching tube of the M, N phase, the on and off states of which are complementary to the upper switching tube of that phase.
Further, step 7, modulating the conduction time of the switching tube with a triangular carrier, outputting a switching tube PWM pulse signal, and completing fault-tolerant control, wherein the specific method comprises:
adopting a DPWM technology to modulate the on-off time of a switching tube and a triangular carrier with a switching period, and adding dead time according to the on-off time of a power switching tube to obtain PWM pulses;
4 paths of PWM pulses act on a power switch tube driving circuit, and the driving circuit controls the corresponding power switch tube to be switched on and off;
and acquiring direct-current voltage at the capacitor side, performing difference between the direct-current voltage and reference voltage, inputting the difference into a PI (proportional-integral) controller, outputting an intermediate variable Tz, and taking the Tz as the input of each sector vector action time module to play a role in adjusting the direct-current side capacitor voltage until the direct-current side capacitor voltage reaches a reference value, thereby completing fault-tolerant control of the electric drive system.
A fault-tolerant control system of a boost three-phase electric driver is used for realizing the fault-tolerant control method of the boost three-phase electric driver.
A computer device comprises a memory, a processor and a computer program which is stored on the memory and can run on the processor, wherein when the processor executes the computer program, the boost type three-phase electric driver fault-tolerant control method is realized.
A computer-readable storage medium, on which a computer program is stored which, when being executed by a processor, carries out the method of fault-tolerant control of a boost-type three-phase electric drive.
Compared with the prior art, the invention has the following remarkable advantages: 1) The method is characterized in that a voltage ring is introduced by combining an SSI inverter topology and a three-phase four-switch driver fault-tolerant topology, and a control algorithm of a switching system after a fault, and the system is switched from the original double-ring control of a rotating speed ring and a current ring to the three-ring control of the rotating speed ring, the rotating speed ring and the current ring, so that the voltage of a capacitor at the direct current side is raised to be twice of the original voltage, and the fault-tolerant control operation with high power quality and full load is realized. 2) After the fault occurs, the voltage of the capacitor is increased to twice of the original voltage, and the voltage vector circle is restored to the value in normal control. The problem of when the fault-tolerant operation of traditional three-phase four-switch, because the voltage vector circle drops to half original, cause rated revolution speed/power to drop half is solved. 3) The fault-tolerant function of the single-stage boost type driver can be realized by only additionally adding three bidirectional thyristors in the three-phase boost type driver by using fewer active devices and changing the topology and the control algorithm after the information of the fault switching tube is obtained, and the size, the cost, the weight and the complexity of the system are reduced. 4) The fault-tolerant control can be completed aiming at all single-tube open-circuit faults, all single-phase open-circuit faults, all single-tube short-circuit faults and all single-phase short-circuit faults.
Drawings
Fig. 1 is a topology diagram of a boost three-phase electric drive with fault-tolerant function.
Fig. 2 is a fault-tolerant control block diagram of a boost three-phase electric drive.
FIG. 3 (a) is a schematic diagram of a three-phase six-switch inverter space vector circle; FIG. 3 (b) is a schematic view of a reduced vector circle after a three-phase six-switch is switched to a conventional three-phase four-switch fault tolerant topology; fig. 3 (c) is a schematic diagram of a voltage vector circle for recovering the normal size by using the fault-tolerant control method.
FIG. 4 (a) is a schematic diagram showing the current flow of a-phase switching tube fault a-phase current at more than zero and less than zero; FIG. 4 (b) is a schematic diagram showing the current flow when the phase-b current is greater than zero and the phase-b bridge arm is in different switching states; FIG. 4 (c) is a schematic diagram showing the current flow when the phase-b current is less than zero and the phase-b bridge arm is in different switching states; FIG. 4 (d) is a schematic diagram showing the current flow when the phase current of the phase-a switching tube is greater than zero and the phase-c bridge arm is in different switching states; fig. 4 (e) is a schematic diagram of the current flow when the phase current of the phase-a switching tube fault phase c is less than zero and the phase arm of the phase c is in different switching states.
Fig. 5 (a) is an equivalent circuit diagram of the system when the a-phase switching tube fails and the switching states are (Sb Sc) = (00), (01), (10); fig. 5 (b) is an equivalent circuit diagram of the system when the a-phase switching tube fails and the switching state is (Sb Sc) = (11).
FIG. 6 (a) is a schematic diagram of three-phase current of the motor in normal operation; FIG. 6 (b) is a schematic diagram of the voltage source input voltage UIn and the DC side capacitor voltage Udc during normal operation; FIG. 6 (c) is a schematic diagram of the motor speed during normal operation; fig. 6 (d) is a schematic diagram of the electromagnetic torque of the motor in normal operation.
Fig. 7 (a) is a schematic diagram of three-phase currents of a motor when an a-phase switching tube is in fault operation; fig. 7 (b) is a schematic diagram of voltage source input voltage UIn and dc side capacitor voltage Udc when the a-phase switching tube operates in fault; FIG. 7 (c) is a schematic diagram of the motor rotation speed when the a-phase switching tube is in fault operation; fig. 7 (d) is a schematic diagram of the electromagnetic torque of the motor during the fault operation of the a-phase switching tube, and it can be seen from the diagram that the motor is in a runaway state after the fault and is dragged by the load to perform reverse rotation operation.
Fig. 8 (a) is a schematic diagram of three-phase currents of a motor during fault-tolerant operation of an a-phase switching tube; fig. 8 (b) is a schematic diagram of voltage source input voltage UIn and dc side capacitor voltage Udc during fault-tolerant operation of the a-phase switching tube; FIG. 8 (c) is a schematic diagram of the motor rotation speed during fault-tolerant operation of the a-phase switching tube; fig. 8 (d) is a schematic diagram of the electromagnetic torque of the motor during fault-tolerant operation of the a-phase switching tube.
Detailed Description
The invention is further illustrated by the following examples in conjunction with the accompanying drawings.
In order to make the objects, technical solutions and advantages of the present application more apparent, the present application 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 present application and are not intended to limit the present application.
Fig. 1 is a voltage boost three-phase electric drive topology with fault tolerance. TR1, TR2, TR3 are bidirectional thyristors; l1 is an inductor; d7, D8 and D9 are diodes; c f A direct current side capacitor; S1-S6 are power switch tubes IGBT; D1-D6 are diodes; F1-F6 are fast fuses; u shape In Is an externally input direct current power supply; udcIs the dc side capacitor voltage. When the system normally operates, the bidirectional thyristors TR1, TR2 and TR3 are kept in a turn-off state, the system is controlled by adopting the conventional three-phase six-switch SVPWM without changing a control algorithm, and the topology has the function of enabling the direct-current power supply U to be connected with the direct-current power supply U In The function of voltage level increase. When a power device of a certain bridge arm of the driver has a short circuit or open circuit fault, the fault bridge arm is disconnected, and meanwhile, a corresponding bidirectional thyristor is opened, so that the switching system is in a three-phase four-switch topology. i.e. i a 、i b 、i c Is the current flowing through the motor phases a, b, c.
Fig. 2 is a boost three-phase electric drive control block diagram. The PMSM is provided with an encoder. The encoder collects the electrical angle theta of the motor during operation e 。θ e And obtaining the motor rotating speed w through differential transformation. Reference value w of the rotational speed * D-axis current reference value I d * Reference value Udc of capacitor voltage on direct current side * Is set by human. When in normal operation, the boost three-phase electric driver adopts a double closed-loop design of a rotating speed outer loop and a current inner loop. The reference rotation speed is set manually. The outer ring of the rotating speed is as follows: and acquiring the rotating speed of the motor, subtracting the rotating speed from the reference rotating speed, inputting the difference into a PI (proportional-integral) regulator, and outputting a q-axis current reference value. The current inner loop is: collecting three-phase current and electric angle of motor, and obtaining d through Park conversion
Figure 357482DEST_PATH_IMAGE001
q-axis current is respectively differed with the d-axis current reference value and the q-axis current reference value, the q-axis current is input into a PI regulator, d and q-axis voltage reference values are output, and alpha-axis voltage reference values and beta-axis voltage reference values are obtained through Park inverse transformation
Figure 595565DEST_PATH_IMAGE002
(ii) a And the input SVPWM control module generates 6 paths of signals for controlling the on-off of the IGBT gate pole. The 6-way gate signal is input into a three-phase six-switch topology. A, b and c three phases are led out from the three-phase six-switch topology and are connected with a motor a, b and c. When the fault-tolerant operation is carried out, three closed loops of a voltage outer loop, a rotating speed outer loop and a current inner loop are adopted for operation. The rotating speed loop, the current loop is consistent with the normal operation, the voltage reference value in the voltage loop is twice of the DC side capacitor voltage in the normal operation, and the voltage reference value is equal to the collected DCAnd (4) subtracting the current side capacitor voltage, inputting the current side capacitor voltage into a PI regulator, outputting Tz, inputting Tz into the modified SVPWM module, and generating 4 paths of signals for controlling the on-off of the IGBT gate pole. The 4-way gate signal is input into a three-phase four-switch topology. Three phases a, b and c are led out from the three-phase four-switch topology and are connected with the three phases a, b and c of the motor. And the PI module continuously adjusts the value of Tz until the direct current side capacitor voltage Udc rises to twice of the original value, and fault-tolerant control is completed.
A fault-tolerant control method of a boost three-phase electric driver comprises the following steps:
step 1, establishing a basic voltage vector under the condition of no fault, as shown in a table 1;
TABLE 1 basic Voltage vector Table under Fault-free conditions
Figure 520796DEST_PATH_IMAGE030
Wherein (Sa Sb Sc) is a switching function of a phase bridge arm, b phase bridge arm and c phase bridge arm, a function value of "1" indicates that the switch tube of the upper bridge arm of the phase is conducted, a function value of "0" indicates that the switch tube of the lower bridge arm of the phase is conducted, different switch state combinations of the switch tubes respectively correspond to 8 basic voltage vectors, which are respectively: u0 (000), U1 (100), U2 (110), U3 (010), U4 (011), U5 (001), U6 (101), U7 (111). In the table, ua, ub and Uc are three-phase voltages of the three-phase driver, uk is a basic voltage vector obtained by Clark conversion of the three-phase voltages of a, b and c, and k is 0~7.Udc is the dc side capacitor voltage.
Step 2, switching the topological structure of the boost three-phase electric driver according to the position of the fault switching tube;
under normal conditions, the system is a boost three-phase six-switch topology, the middle points of two series capacitors between buses are respectively connected to a winding end through 3 bidirectional thyristors, and 2 quick fuses are connected in series in each bridge arm. When the phase a fails, the boost three-phase electric driver is controlled by four switching tubes of the phase b and the phase c, and the bidirectional thyristor TR1 is switched on. When the phase b fails, the boost three-phase electric driver is controlled by four switching tubes of the phase a and the phase c, and the bidirectional thyristor TR2 is switched on. When the phase c fails, the boost three-phase electric driver is controlled by four switching tubes of the phases a and b, and the bidirectional thyristor TR3 is switched on.
The faults are divided into open-circuit faults and short-circuit faults, and the actions of the bidirectional thyristors corresponding to the open-circuit faults are shown in table 2:
TABLE 2 bidirectional thyristor action corresponding to open-circuit fault of different switching tubes
Figure 371202DEST_PATH_IMAGE032
And when the switching tube has a short-circuit fault, the corresponding fast fuse of the switching tube is fused, and the short-circuit fault is converted into an open-circuit fault. The triac and fast fuse actions corresponding to the short circuit fault are shown in table 3:
TABLE 3 bidirectional thyristor and fast fuse action corresponding to different switching tube short-circuit faults
Figure 432699DEST_PATH_IMAGE033
Take a-phase fault as an example. FIG. 3 (a) is a three-phase six-switch inverter space vector circle, each vector having a length of 2Udc/3 and a radius of the vector circle of
Figure 841684DEST_PATH_IMAGE034
Udc/3, udc is the voltage of the capacitor side, fig. 3 (b) is a reconstructed vector circle after a three-phase six-switch is switched to a three-phase four-switch fault-tolerant topology after a phase fault occurs, the length of the short vector is Udc/3, and the length of the long vector is Udc
Figure 254211DEST_PATH_IMAGE034
Udc/3, the radius of the vector circle is reduced to half of the original radius
Figure 908308DEST_PATH_IMAGE034
Udc/6. When the conventional three-phase six-switch driver is switched to a four-switch driver, the rated output power is also reduced to half of the original rated output power due to the reduction of the space vector circle to half of the original rated output power. To maintain the rated output torque, the rated rotational speed needs to be reduced to half of the original rotational speed. Having fault toleranceA boost-type three-phase six-switch SSI driver of capacity can just solve this problem. When the boost three-phase six-switch SSI topology is switched to the boost three-phase four-switch SSI topology, the vector circle is also reduced, and the reduction size is related to the zero vector acting time of the system. The boost three-phase four-switch SSI driver is used for further boosting the dc voltage to double the dc side capacitor voltage of the original three-phase six-switch SSI topology, so that each reduced vector is expanded to double the original vector, and the vector circle is restored to the original size. As shown in fig. 3 (c), when the radius of the voltage vector circle is restored to the original one
Figure 89891DEST_PATH_IMAGE034
And when the voltage is Udc/3, the full-power fault-tolerant operation of the system can be realized.
Step 3, reconstructing a basic voltage vector under the condition of single tube or single-phase fault;
determining the relation between the motor phase voltage and the switch state as follows:
Figure 404198DEST_PATH_IMAGE008
defining a three-phase composite voltage space vector:
Figure 304020DEST_PATH_IMAGE035
in the formula
Figure 496230DEST_PATH_IMAGE010
Is a spatial rotation factor.
Sa, sb and Sc respectively represent the switching states of power devices on the bridge arms a, b and c, when the switching states are equal to '1', the upper tube is switched on, the lower tube is switched off, and when the switching states are equal to '0', the upper tube is switched on, and the upper tube is switched off. When the phase a fails, the motor winding phase a is connected to the middle point of the capacitor, and Sa is constant 1/2. The boost three-phase electric driver is controlled by four switching tubes of b and c phases and has 4 switching states of (Sb Sc) = (0), (Sb Sc) = (1), and (Sb Sc) = (1). When the phase b fails, the motor winding a is connected to the middle point of the capacitor, and Sb is constant at 1/2. The boost three-phase electric driver is controlled by four switching tubes of c and a phases and has 4 switching states of (Sc Sa) = (0), (Sc Sa) = (1) and (Sc Sa) = (1). When the phase c fails, the motor winding phase c is connected to the middle point of the capacitor, and Sc is constant to 1/2. The boost three-phase electric driver is controlled by four switching tubes of a phase and a phase b and has 4 switching states of (SaSb) = (0), (SaSb) = (1). U0', U1', U2', and U3' correspond to the basic voltage vectors in the switching states of the two-phase switching tubes (00), (01), (10), and (11) that operate after the failure.
The basic voltage vectors for the reconstructed single tube or single phase fault conditions are shown in Table 4
Table 4 reconstructed basic voltage vector table
Figure 797898DEST_PATH_IMAGE036
After a fault occurs to one of the three phases a, b and c, the four basic voltage vectors U0', U1', U2 'and U3' are all sequenced in a clockwise mode in the plane, and each adjacent vector is separated by 90 degrees. In order to simplify the calculation of reference vectors after the faults of the phases a, b and c are unified, coordinate axes are made
Figure 283106DEST_PATH_IMAGE013
’、
Figure 670225DEST_PATH_IMAGE037
The ' positive direction is the positive direction of the basic voltage vectors U0', U2'. Reference vector
Figure 666125DEST_PATH_IMAGE015
In that
Figure 556721DEST_PATH_IMAGE013
’、
Figure 478409DEST_PATH_IMAGE037
' projection on axis of
Figure 87245DEST_PATH_IMAGE016
、
Figure 886836DEST_PATH_IMAGE017
。
Take a-phase switching tube failure as an example. The direction of the current flowing into the motor is defined as the positive direction of the current. When the a-phase switch tube is in fault, the a-phase switch tube is connected to the midpoint of the direct-current side capacitor through the bidirectional thyristor. Fig. 4 (a) to 4 (e) show the current flows of the three-phase currents a, b, and c in the respective switching vector states. FIG. 4 (a) is a current flow direction for phase a current above zero and below zero; FIG. 4 (b) is the current flow direction when the phase b current is greater than zero and the phase b bridge arm is in different switch states; FIG. 4 (c) shows the current flow direction of the b-phase bridge arm in different switch states when the phase b current is less than zero; FIG. 4 (d) shows the current flow direction of the c-phase bridge arm in different switch states when the c-phase current is greater than zero; fig. 4 (e) shows the current flow when the c-phase current is less than zero and the c-phase arm is in different switching states. Fig. 5 (a) to 5 (b) are schematic diagrams illustrating three-phase four-switch fault-tolerant SSI charging and discharging equivalent circuits. S 6，2 Indicating that one of the switching tubes S6, S2 is on and that both switching tubes S6, S2 are on. S. the 3，5 Indicating that both switching tubes S3, S5 are on. Fig. 5 (a) is an equivalent circuit diagram of the system when the switching states are (Sb Sc) = (00), (01), and (10). At this time, the system is coupled to the capacitor C f Discharging and charging the inductor L1. Fig. 5 (b) is an equivalent circuit diagram of the system when the switching state is (Sb Sc) = (11). At this time, the system is coupled to the capacitor C f Charging and discharging of the inductor L1. Therefore, of the four switching states, only (Sb Sc) = (11) is the capacitance C f Charging and discharging of the inductor L1. By distributing different vector action times, i.e. by distributing capacitance C f The charging and discharging time of the inductor L1 can be controlled to control the direct current voltage U at the capacitor side In The object of (1).
Step 4, a four-sector division mode is adopted to divide the sectors, and the method specifically comprises the following steps:
defining a function:
Figure 897517DEST_PATH_IMAGE018
；
Figure 990107DEST_PATH_IMAGE019
defining a sector calculation value N function:
Figure 86239DEST_PATH_IMAGE020
determining the corresponding relation between the calculated value of N and the actual sector number through a table 5, and completing sector division;
TABLE 5 calculated value and sector correspondence of 5N
Figure 423942DEST_PATH_IMAGE039
Step 5, selecting action vectors from the reconstructed basic voltage vectors;
the basic voltage vectors U0 'to U3' can be used as effective vectors independently, and two opposite-direction vectors can be used as equivalent zero vectors. Since there is no zero vector in the four-switch system, the equivalent zero vector needs to apply 2 basic voltage vectors in opposite directions to be equivalent in the same time. Using U0 '(00), U3' (11) as a pair of equivalent zero vectors; u1 '(01), U2' (10) are used as another pair of equivalent zero vectors. The valid vector and the equivalent zero vector together synthesize a reference vector.
Considering the minimum switching loss, when the reference vector is positioned in the first sector, selecting the basic voltage vectors to act in the sequence of U2', U0', U1 'and U3'; when the reference vector is positioned in a second sector, selecting the basic voltage vectors to act in the sequence of U3', U2', U0 'and U1'; when the reference vector is positioned in the third sector, selecting the basic voltage vectors with the action sequence of U1', U3', U2 'and U0'; when the reference vector is positioned in the fourth sector, the action sequence of the basic voltage vectors is selected to be U0', U1', U3 'and U2'.
In the boost three-phase four-switch SSI, four switch states (00), (01), (10), and (11) correspond to four basic voltage vectors, wherein three basic voltage vectors, i.e., U0 '(00), U1' (01), and U2 '(10), are used to discharge a capacitor and charge an inductor, and only U3' (11) is used to charge a capacitor and discharge an inductor. In each switching cycle, the reference vector is composed of a valid vector and an equivalent zero vector. The effective vector is fixed, while the equivalent zero vector can be synthesized by U0 '(00), U3' (11) or U1 '(01), U2' (10). There are two pairs of equivalent zero vectors, the sum of the action time of the two pairs of equivalent zero vectors is fixed, but the action time of each pair of zero vectors can be distributed according to requirements. The purpose of controlling the capacitor voltage can be achieved by controlling the relative time of the two pairs of equivalent zero vectors U0', U3' and U1 'and U2'.
Step 5, determining the acting time of the basic voltage vector after the fault;
defining the intermediate variables:
Figure 289130DEST_PATH_IMAGE023
in the formula, udc is the direct current side capacitor voltage, and Ts is the switching period;
the active vector action time of each sector is defined as Tx, ty. Effective vectors acted by the first sector are U0 'and U2', and action time is Tx and Ty respectively; effective vectors acted by the second sector are U2 'and U3', and action time is Tx and Ty respectively; the effective vectors acted by the third sector are U3 'and U1', and the acting time is Tx and Ty respectively; the effective vectors of the fourth sector are U1 'and U0', and the action time is Tx and Ty respectively. From table 6, the effective vector acting times Tx and Ty in the basic voltage vectors of the sectors in the division of four sectors are determined:
TABLE 6 action time T1 and T2 of each sector valid vector when four sectors are divided
Figure 427987DEST_PATH_IMAGE040
Defining an equivalent zero vector action time:
T0=Ts-Tx-Ty
the equivalent zero vector of each sector is jointly synthesized by U0', U1', U2 'and U3', and U0 'and U3' are a pair; u1 'and U2' are a pair; the two vectors in each pair are equal in duration.
Defining the intermediate variables:
0<=Tz<=T0
let the action time of a pair of vectors U1 'and U2' be
Figure 136049DEST_PATH_IMAGE026
、
Figure 385765DEST_PATH_IMAGE026
(ii) a The other pair of vectors U0 'and U3' has an action time of
Figure 997137DEST_PATH_IMAGE027
、
Figure 306895DEST_PATH_IMAGE027
. In a switching period, an effective vector based on the basic voltage vector and an equivalent zero vector act together to synthesize a reference vector. The base voltage vector action time for each sector is determined by table 7:
TABLE 7 fundamental Voltage vector action time for each sector
Figure 502253DEST_PATH_IMAGE041
。
Step 6, determining the conduction time of each switching tube after the step-up three-phase electric driver reconstructs topology;
after the topology is reconstructed, the boost three-phase electric driver is controlled by four IGBT power switching tubes, namely a three-phase four-switch topology. Determining the switching time point of each switching tube after the topology is reconstructed through the table 8 in a switching period according to the vector action time of each sector in the table 7;
table 8 switching time points of each switching tube after topology reconstruction
Figure 555660DEST_PATH_IMAGE042
In the table, M, N takes values a, b, and c. When M = a, b, c, the corresponding N = b, c, a. 5363 the on and off time points of a phase M, N represent the on and off times of the upper switching tube of the M, N phase, the on and off states of which are complementary to the upper switching tube of that phase.
And 7, modulating the on-off time and the period of the switching tube by adopting a DPWM technology, and adding the modulated pulse into dead time according to the on-off time of the power switching tube to obtain the PWM pulse. And 4 paths of output PWM pulses act on the power switch tube driving circuit, and the driving circuit controls the corresponding power switch tube to be switched on and off. And acquiring direct-current voltage at the capacitor side, performing difference with reference voltage, inputting the difference into a PI (proportional-integral) controller, outputting variables Tz and Tz as the input of the modified SVPWM module, and playing a role in regulating the direct-current voltage at the capacitor side until the direct-current voltage at the capacitor side reaches a reference value, thereby completing full-power fault-tolerant control of the electric drive system.
According to the invention, through acquiring the fault information and changing the corresponding system hardware topology and control algorithm, the state recovery under the condition of open circuit fault or short circuit fault of all single tubes and double tubes of the same bridge arm can be realized, and the fault-tolerant operation with high power quality and full load is achieved.
In order to verify the effectiveness of the scheme of the invention, the fault-tolerant control method is verified by taking the fault of the a-phase switching tube as an example.
FIG. 6 (a) shows three-phase currents of the motor during normal operation; FIG. 6 (b) shows the voltage source input voltage U during normal operation In With the dc-side capacitor voltage Udc, it can be seen from the figure that the input voltage U In The voltage is 20V, and after the voltage is boosted by the circuit, the direct-current side capacitor voltage Udc is 115V; FIG. 6 (c) shows the motor rotation speed at 30rad/s in normal operation; fig. 6 (d) shows the electromagnetic torque of the motor in normal operation, which is about 11n × m.
Fig. 7 (a) shows that when the a-phase switching tube fails, the three-phase current of the motor is in fault operation, and the amplitude of the three-phase current is increased sharply as can be seen from the graph; FIG. 7 (b) shows the input voltage U of the voltage source during fault operation In With the DC side capacitor voltage Udc, the input voltage U In Still 20V, it can be seen that the DC side capacitor voltage is slightly increased from 115V when normal; fig. 7 (c) shows the rotation speed of the motor during fault operation, and it can be seen from the graph that the rotation speed is reduced to a negative value, and the motor is in an out-of-control state at this time and is dragged by the load to perform reverse rotation operation. Fig. 7 (d) shows the electromagnetic torque of the motor during the fault operation, and it can be seen from the graph that the electromagnetic torque of the motor is abruptly oscillated and has a negative value. The entire system is in a crash state at this time.
Fig. 8 (a) shows three-phase currents of the motor during fault-tolerant operation, and it can be seen from the diagram that the three-phase currents are basically restored to the state during normal operation; FIG. 8 (b) is a diagram of the voltage source input voltage U for fault tolerant operation In With the DC side capacitor voltage Udc, the input voltage U In The voltage of the direct-current side capacitor Udc is still 20V, and is raised to twice that of the direct-current side capacitor Udc in normal operation according to the requirement, and is 230V, so that the system can recover full-power operation; FIG. 8 (c) shows the motor rotation speed during fault-tolerant operation, which is 30rad/s when the motor rotation speed is restored to the normal operation state; fig. 8 (d) shows the electromagnetic torque of the motor during fault-tolerant operation, and the electromagnetic torque is also restored to the state during normal operation, so that the motor operates stably.
From the results of fig. 7 (a) -7 (d) and fig. 8 (a) -8 (d), it can be seen that the fault-tolerant control method for the boost three-phase electric driver can perform good control action on current, rotating speed, torque and direct-current side capacitor voltage after the system fault after the single-phase fault of the driver, still can realize the fault-tolerant operation of the driver with high power quality and full load, and enhance the reliability of the system.
The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present application. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, and these are all within the scope of protection of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.

Claims (10)

1. A step-up three-phase electric driver is characterized in that two capacitors C connected in series are arranged on the direct current side f The middle points of the two capacitors are respectively connected to a winding end of a three-phase a, a winding end of a three-phase b and a winding end of a three-phase c through 3 bidirectional thyristors TR1, TR2 and TR3, and the other ends of the series capacitors are respectively connected with a phase a, a phase b and a phase c of a three-phase bridge arm; power supply U In The negative pole of the lower bridge arm is connected with the a phase, the b phase and the c phase of the three-phase bridge arm, the positive pole of the lower bridge arm is connected with an inductor L1, the other end of the inductor L1 is connected with the positive poles of diodes D7, D8 and D9, and the negative poles of the diodes D7, D8 and D9 are respectively connected with the a, b and c three-phase winding ends; the three-phase bridge arm phases a, b and c consist of six IGBT power switch tubes S1-S6 and six diodes D1-D6 connected with the switch tubes in parallel, each phase of bridge arm is connected with 2 fast fuses in series, and 6 fast fuses F1-F6 are provided; when a power device of a certain bridge arm of the driver has a short-circuit fault, the corresponding fast fuse is fused, and the fault bridge arm is disconnected; when the switching system is in an open-circuit fault, the fault bridge arm automatically fails, the input of a driving signal of a switching tube of the fault bridge arm is stopped, the corresponding bidirectional thyristor is opened, and the switching system is in a boost three-phase four-switch topological structure.
2. A boost three-phase electric driver according to claim 1, wherein the normal operation uses a rotating speed outer ring and a current inner ring for double closed-loop operation, wherein the rotating speed ring collects the rotating speed of the motor, and the rotating speed is differentiated from a reference rotating speed to be input into a PI regulator, and a q-axis current reference value is output; the current loop collects three-phase current and the electrical angle of the motor, and d is obtained through Park conversion
Figure 430584DEST_PATH_IMAGE001
q-axis current, respectively subtracting the reference values of d-axis current and q-axis current, inputting the difference into a PI regulator, outputting the reference values of d-axis voltage and q-axis voltage, and obtaining alpha-axis voltage reference values and beta-axis voltage reference values through Park inverse transformation
Figure 239402DEST_PATH_IMAGE002
Inputting the signals into an SVPWM control module to generate 6 paths of signals for controlling the on-off of the IGBT gate pole;
and during fault-tolerant operation, a voltage and rotating speed outer ring and a current inner ring are adopted for three closed-loop operation, wherein the rotating speed ring and the current ring are consistent with normal operation, the voltage reference value in the voltage ring is twice of the direct-current side capacitor voltage during normal operation, the difference is made between the voltage reference value and the collected direct-current side capacitor voltage, the voltage reference value is input into a PI regulator, an intermediate variable Tz is output and input into an SVPWM module, and the PI module continuously adjusts the value of the Tz until the direct-current side capacitor voltage Udc is raised to twice of the original value, so that fault-tolerant control is completed.
3. A method for fault-tolerant control of a boost three-phase electric drive, wherein fault-tolerant control is performed based on the boost three-phase electric drive of any one of claims 1-2, comprising the steps of:
step 1, establishing a basic voltage vector under the condition of no fault;
step 2, switching the topological structure of the boost three-phase electric driver according to the position of the fault switching tube;
step 3, reconstructing a basic voltage vector under the condition of single tube or single-phase fault;
step 4, a 4-sector division mode is adopted to divide the sectors;
step 5, selecting action vectors from the reconstructed basic voltage vectors, and determining corresponding action time;
step 6, determining the conduction time of each switching tube after the step-up three-phase electric driver reconstructs topology;
and 7, modulating the conduction time of the switching tube with a triangular carrier, and outputting a PWM pulse signal of the switching tube to finish fault-tolerant control.
4. A boost-type three-phase electric drive fault-tolerant control method according to claim 3, characterized in that step 1, a basic voltage vector in a fault-free condition is established, as shown in table 1:
TABLE 1 Fault-free basic Voltage vector Table
Figure 19140DEST_PATH_IMAGE003
Wherein (Sa Sb Sc) is a switching function of a phase bridge arm, b phase bridge arm and c phase bridge arm, a function value of "1" indicates that the switch tube of the upper bridge arm of the phase is conducted, a function value of "0" indicates that the switch tube of the lower bridge arm of the phase is conducted, different switch state combinations of the switch tubes respectively correspond to 8 basic voltage vectors, which are respectively: u0 (000), U1 (100), U2 (110), U3 (010), U4 (011), U5 (001), U6 (101) and U7 (111), wherein Ua, ub and Uc in the table are three-phase voltage of a three-phase driver, uk is a basic voltage vector obtained by Clark conversion of three-phase voltages of a, b and c, k is 0 to 7, and udc is direct-current side capacitance voltage.
5. A boost three-phase electric drive fault-tolerant control method according to claim 3, wherein step 2, the topology of the boost three-phase electric drive is switched according to the position of the faulty switching tube, and the method comprises:
when a phase fails, the boost three-phase electric driver is controlled by four switching tubes of b and c phases, when b phase fails, the boost three-phase electric driver is controlled by four switching tubes of c and a phases, when c phase fails, the boost three-phase electric driver is controlled by four switching tubes of a and b phases, and because the faults include an open-circuit fault and a short-circuit fault, the action of the bidirectional thyristor corresponding to the open-circuit fault is as shown in table 2:
TABLE 2 bidirectional thyristor action corresponding to different switching tube open-circuit faults
Figure 273403DEST_PATH_IMAGE004
When the switch tube has a short-circuit fault, the fast fuse corresponding to the switch tube is fused, the short-circuit fault is converted into an open-circuit fault, and the action of the bidirectional thyristor and the fast fuse corresponding to the short-circuit fault is shown in table 3;
TABLE 3 bidirectional thyristor corresponding to different switch tube short-circuit faults and quick fuse action
Figure 87776DEST_PATH_IMAGE006
。
6. The fault-tolerant control method for the boost three-phase electric driver according to claim 5, wherein in step 3, the basic voltage vector under the condition of single tube or single-phase fault is reconstructed by the following specific method:
determining the relation between the motor phase voltage and the switch state:
Figure 801916DEST_PATH_IMAGE007
in the formula, ua, ub and Uc are three-phase voltages of a three-phase driver, sa, sb and Sc respectively represent the switching states of power devices on bridge arms a, b and c, when the switching states are equal to '1', an upper tube is switched on, a lower tube is switched off, and when the switching states are equal to '0', the upper tube is switched on, and the upper tube is switched off; when the phase a fails, the motor winding phase a is connected to the middle point of the capacitor, and Sa is constant 1/2; the boost three-phase electric driver is controlled by four switching tubes of b and c phases and has 4 switching states of (Sb Sc) = (0), (Sb Sc) = (1) and (Sb Sc) = (1); when a phase b fails, the motor winding b is connected to the middle point of a capacitor, sb is constantly 1/2, the boost three-phase electric driver is controlled by four switching tubes of phases c and a, and has 4 switching states of (Sc Sa) = (0), (Sc Sa) = (1); when the c phase fails, the motor winding c is connected to the middle point of the capacitor, sc is constant to 1/2, the boost three-phase electric driver is controlled by four switching tubes of the a phase and the b phase, and has 4 switching states of (SaSb) = (0), (SaSb) = (1);
determining a three-phase composite voltage space vector:
Figure 68949DEST_PATH_IMAGE008
in the formula
Figure 392483DEST_PATH_IMAGE009
For rotating in spaceA factor;
determining a basic voltage vector under the condition of reconstructing a single tube or single-phase fault, as shown in table 4;
table 4 reconstructed basic voltage vector table
Figure 61362DEST_PATH_IMAGE010
After a fault occurs to one of the three phases a, b and c, the four basic voltage vectors U0', U1', U2 'and U3' are sequenced in the plane according to the clockwise sequence of U0', U1', U3 'and U2', each adjacent vector is separated by 90 degrees, and in order to simplify the calculation of the reference vector after the fault of each phase, the coordinate axes are made to be unified
Figure 415245DEST_PATH_IMAGE011
’、
Figure 169575DEST_PATH_IMAGE012
The positive direction is the positive direction of the basic voltage vectors U0 'and U2', reference vector
Figure 906586DEST_PATH_IMAGE013
In that
Figure 820185DEST_PATH_IMAGE011
’、
Figure 250029DEST_PATH_IMAGE012
' projection on axis of
Figure 117753DEST_PATH_IMAGE014
、
Figure 392877DEST_PATH_IMAGE015
。
7. The fault-tolerant control method of the boost-type three-phase electric driver of claim 6, wherein in step 4, a four-sector division method is adopted to divide sectors, and the specific method is as follows:
defining a function:
Figure 895402DEST_PATH_IMAGE016
；
Figure 230569DEST_PATH_IMAGE017
define sector calculation value N:
Figure 851168DEST_PATH_IMAGE018
determining the corresponding relation between the N and the actual sector number through the table 5 to complete sector division;
table 5N calculation value and sector corresponding relation table
Figure 929982DEST_PATH_IMAGE020
。
8. The fault-tolerant control method of a boost-type three-phase electric drive according to claim 7, characterized in that step 5, selecting an action vector from the reconstructed base voltage vector and determining a corresponding action time by:
step 5.1, selecting action vectors from the reconstructed basic voltage vectors;
the action vector comprises an effective vector and a zero vector, the basic voltage vectors U0 '-U3' are independently used as the effective vector, the two basic voltage vectors in opposite directions are taken to synthesize an equivalent zero vector, namely, an equivalent zero vector is synthesized by using U0 '(00) and U3' (11), and the other equivalent zero vector is synthesized by using U1 '(01) and U2' (10); synthesizing the effective vector and the equivalent zero vector into a reference vector;
considering the minimum switching loss, when the reference vector is positioned in the first sector, selecting the basic voltage vectors to act in the sequence of U2', U0', U1 'and U3'; when the reference vector is positioned in the second sector, selecting the basic voltage vectors with the action sequence of U3', U2', U0 'and U1'; when the reference vector is positioned in the third sector, selecting the basic voltage vectors with the action sequence of U1', U3', U2 'and U0'; when the reference vector is positioned in the fourth sector, selecting the basic voltage vectors as U0', U1', U3 'and U2';
step 5.2, determining the action time of the action vector;
defining the intermediate variables:
Figure 427960DEST_PATH_IMAGE021
wherein Ts is a switching period;
setting effective vectors acted by the first sector as U0 'and U2', and respectively setting action time as Tx and Ty; effective vectors acted by the second sector are U2 'and U3', and action time is Tx and Ty respectively; the effective vectors acted by the third sector are U3 'and U1', and the action time is Tx and Ty respectively; effective vectors acted by the fourth sector are U1 'and U0', and action time is Tx and Ty respectively; determining the action time of the effective vector of each sector through a table 6;
TABLE 6 Effect time of the effective vector of each sector
Figure 58661DEST_PATH_IMAGE022
Defining the action time of the equivalent zero vector:
T0=Ts-Tx-Ty
since the equivalent zero vector of each sector is jointly synthesized by U0', U1', U2', U3', an intermediate variable is defined:
0<=Tz<=T0
the action time of two basic voltage vectors of the synthesized equivalent zero vector is equal, then the action time of U1 'and U2' is
Figure 9300DEST_PATH_IMAGE023
、
Figure 783483DEST_PATH_IMAGE023
(ii) a The action time of U0 'and U3' is
Figure 135967DEST_PATH_IMAGE024
、
Figure 203149DEST_PATH_IMAGE024
；
The base voltage vector action time for each sector is determined by table 7:
TABLE 7 fundamental Voltage vector action time for each sector
Figure 641084DEST_PATH_IMAGE025
。
9. The fault-tolerant control method for the boost three-phase electric driver according to claim 3, wherein in the step 6, the conduction time of each switching tube after the topology of the boost three-phase electric driver is reconstructed is determined by:
table 8 switching time points of each switching tube after topology reconstruction
Figure 422220DEST_PATH_IMAGE026
In a switching period, determining the switching time point of each switching tube after the topology is reconstructed through a table 8, wherein in the table, the values of M, N are all a, b and c, and when M = a, b and c, corresponding N = b, c and a;
5363 the on and off time points of the phase M, N represent the on and off times of the upper switching tube of the M, N phase, the on and off states of the lower switching tube of this phase being complementary to the upper switching tube of this phase.
10. The fault-tolerant control method of the boost three-phase electric driver according to claim 3, wherein in step 7, the conduction time of the switching tube is modulated with a triangular carrier, and a PWM pulse signal of the switching tube is output to complete fault-tolerant control, and the method specifically comprises the following steps:
adopting a DPWM technology to modulate the on-off time of a switching tube and a triangular carrier with a switching period as a cycle, and adding dead time according to the on-off time of a power switching tube to obtain PWM pulses;
applying 4 paths of PWM pulses to a power switching tube driving circuit, and controlling the corresponding power switching tube to be switched on and off by the driving circuit;
and acquiring direct-current voltage at the capacitor side, performing difference between the direct-current voltage and reference voltage, inputting the difference into a PI (proportional-integral) controller, outputting an intermediate variable Tz, and taking the Tz as the input of each sector vector action time module to play a role in adjusting the direct-current side capacitor voltage until the direct-current side capacitor voltage reaches a reference value, thereby completing fault-tolerant control of the electric drive system.
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116633185A (en) * 2023-07-19 2023-08-22 南京理工大学 Boost grid-connected inverter and control method thereof

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107800318A (en) * 2017-08-03 2018-03-13 中南大学 A kind of control method of grid-connected inverter and system
CN110829926A (en) * 2019-10-24 2020-02-21 江苏大学 SVPWM fault-tolerant control method and device for five-phase permanent magnet fault-tolerant motor
CN113629760A (en) * 2021-07-27 2021-11-09 重庆大学 Hardware fault-tolerant control method for wind power converter

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107800318A (en) * 2017-08-03 2018-03-13 中南大学 A kind of control method of grid-connected inverter and system
CN110829926A (en) * 2019-10-24 2020-02-21 江苏大学 SVPWM fault-tolerant control method and device for five-phase permanent magnet fault-tolerant motor
CN113629760A (en) * 2021-07-27 2021-11-09 重庆大学 Hardware fault-tolerant control method for wind power converter

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
贺虎成等: "新型三相容错逆变器研究", 《电力自动化设备》 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116633185A (en) * 2023-07-19 2023-08-22 南京理工大学 Boost grid-connected inverter and control method thereof
CN116633185B (en) * 2023-07-19 2023-11-10 南京理工大学 Boost grid-connected inverter and control method thereof

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