A multi-working-state three-phase motor driver and a fault-tolerant control method thereof

Abstract

The application discloses a kind of multi-working state three-phase motor driver and its fault-tolerant control method, normal operation, select ordinary three-phase six-switch topology;When DC side voltage power supply is insufficient, switch variable boost ratio type three-phase six-switch topology and its control algorithm, variable boost ratio type three-phase six-switch topology changes boost ratio by controlling the action time of zero vector in basic vector;After single tube or single-phase switch tube failure, it is switched to boost type three-phase four-switch topology and its control algorithm by variable boost ratio type three-phase six-switch topology, select action vector from reconstructed basic voltage vector, using new algorithm similar to six-switch, recalculate the action time of basic vector;According to basic vector action sequence and basic vector action time, determine the action time of switch state, to generate PWM signal, control switch tube on-off complete control.The application can realize the recovery work performance of driver after different failures, improve the reliability and stability of motor driver system.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of motor drive control, and particularly relates to a multi-working-state three-phase motor driver and a control method thereof. BACKGROUND

[0002] With the development of power semiconductor devices such as IGBT, MOSFET and the progress of power electronics technology, the application scenarios of inverters are changed from medium and low voltage motor drives such as fans and compressors to high-power and high-capacity motor drives, which are widely used in many fields such as electric vehicles, wind power generation, industrial control, automation equipment, etc. For example, the motor drive system of the rapidly developing new energy electric vehicle and the variable pitch motor drive system of wind power generation. Therefore, the drive and control of the motor play a crucial role. The traditional two-level inverter has been widely used in the field of motor drive. However, due to its single working state, it may not run normally in different situations when facing complex and changeable external environment or unstable factors itself, such as insufficient power supply of DC power supply system, single tube or single phase fault.

[0003] Therefore, based on the wide application background of the motor driver and its commonly used structure, the application strategy of combining the boost driving topology with the ordinary three-phase six-switch topology is adopted, and a multi-working-state driver is obtained to cope with complex and changeable situations. In normal operation, the motor is driven by three-phase six-switch, when the DC power supply cannot meet the full power operation of the motor, the motor is driven by variable boost ratio three-phase six-switch, and when the driver fails, the boost topology quickly intervenes and switches to boost three-phase four-switch operation to ensure that the motor can still run stably. The driver not only can run in multiple working states, but also is a single-stage DC-AC driver with boost function, which is superior to two-stage driver in size, cost, weight and complexity of the whole system. The paper "Three-Phase Split-Source Inverter (SSI): Analysis and Modulation" analyzes the working mode and modulation method of split-source inverter SSI. However, there is no research on the combination of boost topology and ordinary three-phase six-switch driver and the realization of multi-working-state driver. Therefore, the proposal of the driver has great significance to improve the stability of the whole motor drive system, and also has high social and economic value. SUMMARY

[0004] The application aims to provide a multi-working-state three-phase motor driver and a control method thereof.

[0005] The technical solution for achieving the purpose of the application is as follows: a multi-working-state three-phase motor driver is composed of a three-phase six-switch two-level drive inverter, an additional boost topology and a switching device for topology reconstruction, wherein:

[0006] (1) Three-phase six-switch two-level inverter:

[0007] Each phase of the three-phase six-switch two-level inverter is composed of an upper bridge arm and a lower bridge arm. The six bridge arms are composed of six IGBT power switches S1-S6 and six diodes D1-D6 connected in parallel with the power switches. There are six fast fuses F1-F6, each connected in series with the upper and lower bridge arms of each of the three phases A, B, and C. The positive electrode of the DC power supply U In is first connected to the bidirectional thyristor S7, and then connected to the upper bridge arms of the three-phase bridge arms A, B, and C, respectively. In The negative electrode is connected to the lower bridge arms of the three-phase bridge arms A, B, and C, respectively. The midpoints of the upper and lower bridge arms of the three phases A, B, and C are connected to the a, b, and c phase windings of the permanent magnet synchronous motor, respectively. a , i b , i c are the currents flowing through the a, b, and c phase windings of the motor.

[0008] (2) Additional boost topology and switching devices for topology reconstruction:

[0009] Two capacitors C f are connected in series. The positive electrode of the series capacitor is connected to the bidirectional thyristor S8, and then connected to the bidirectional thyristor S7. The negative electrode of the series capacitor is connected to the DC power supply U In . The midpoints of the two capacitors C f are connected to the midpoints of the upper and lower bridge arms of the three phases A, B, and C through three bidirectional thyristors TR1, TR2, and TR3, respectively, and then connected to the a, b, and c phase windings of the permanent magnet synchronous motor, respectively. In The positive electrode of the DC power supply U is first connected to the bidirectional thyristor S9, and then connected to the inductor L1. The other end of the inductor L1 is connected to the positive electrodes of the diodes D7, D8, and D9. The negative electrodes of the diodes D7, D8, and D9 are connected to the a, b, and c phase windings, respectively.

[0010] Further, when operating normally, the bidirectional thyristor S7 is open, the bidirectional thyristor S8 and the bidirectional thyristor S9 are closed, and the topology operates in the ordinary three-phase six-switch topology.

[0011] When the DC power supply cannot meet the full power operation of the motor, the bidirectional thyristor S7 is closed, the bidirectional thyristor S8 and the bidirectional thyristor S9 are opened, and the topology is switched from the ordinary three-phase six-switch topology to the variable boost ratio three-phase six-switch topology.

[0012] When the IGBT power switch tube of a certain bridge arm of the driver is short-circuited and the corresponding fast fuse is blown, or is directly open-circuited, the bidirectional thyristor S7 is turned off, the bidirectional thyristor S8 and the bidirectional thyristor S9 are turned on, and the bidirectional thyristor TR1, TR2 or TR3 connected to the corresponding phase of the fault IGBT power switch tube is turned on, so that the three-phase four-switch topology is switched to the boost type.

[0013] Further, the multi-working-state three-phase motor driver adopts double closed loops of speed outer ring and current inner ring, wherein the speed ring inputs a PI regulator with a difference between a motor speed obtained by collection and a reference speed, and outputs a q-axis current reference value; the current ring takes zero d-axis as a d-axis current reference value, and then collects three-phase currents and motor electrical angles, and obtains d-axis and q-axis currents through Park transformation, and inputs a PI regulator with a difference between the d-axis and q-axis currents and the d-axis and q-axis current reference values respectively, and outputs d-axis and q-axis voltage reference values, which are obtained through Park inverse transformation to obtain α-axis and β-axis voltage reference values U α 、U β ; U α 、U β are input to normal SVPWM control modules, variable boost SVPWM control modules and fault-tolerant SVPWM control modules corresponding to different working states, to generate signals for controlling the on-off of IGBT gates, and the gate signals are input to topologies corresponding to different working states.

[0014] A control method of a multi-working-state three-phase motor driver, which is based on the multi-working-state three-phase motor driver to complete control, comprising:

[0015] (1) Normal SVPWM control

[0016] When normally running, the bidirectional thyristor S7 is turned on, the bidirectional thyristor S8 and the bidirectional thyristor S9 are turned off, and the normal SVPWM control is run in the ordinary three-phase six-switch topology, which first determines the basic voltage vector of each sector synthesized reference vector and the action order and action time of the basic voltage vector when the ordinary three-phase six-switch topology normally runs, and then determines the action time of the IGBT power switch tube switching state according to the action order and action time of the basic voltage vector, generates 6 PWM signals to control the on-off of the IGBT power switch tube, and completes the control of the normal three-phase motor driver;

[0017] (2) Variable boost SVPWM control

[0018] When the DC power supply cannot meet the full power operation of the motor, the bidirectional thyristor S7 is turned off, the bidirectional thyristor S8 and the bidirectional thyristor S9 are turned on, and the variable boost ratio type three-phase six-switch topology is switched, which feeds back the energy of the DC power supply U In to the front-end capacitor C fIn the middle, and realize the effect of boost, variable boost SVPWM control first determines the inductance discharge time and inductance charging time, define duty ratio and boost gain, and then based on the boost control strategy, recalculate the basic voltage vector of each sector action time, then according to the basic voltage vector action order and action time, determine the IGBT power switch tube switch state of action time, produce 6 PWM signal, IGBT control power switch tube on-off, complete variable boost ratio type three-phase motor driver control;

[0019] (3) fault-tolerant SVPWM control

[0020] When the driver of a bridge arm power switch tube short circuit fault corresponding fuse fuse, or direct open circuit fault, switch to boost type three-phase four switch topology, fault-tolerant SVPWM control using six switch new modulation algorithm, first reconstruct the basic voltage vector of single tube or single-phase fault, and synthesis virtual vector; Then select the action vector to re-6 sector division, and determine the action order and action time of the action vector of each sector synthesized reference vector; Then the action time of the virtual vector is allocated to the four basic voltage vectors, and the action order and action time of the basic voltage vector of the synthesized reference vector of each sector are determined; Finally, according to the basic voltage vector action order and action time, the action time of the IGBT power switch tube switch state is determined, so as to generate 4 PWM signal, control IGBT power switch tube on-off complete boost type motor driver fault-tolerant control.

[0021] Further, (1) normal SVPWM control, the specific method is:

[0022] Determine the basic voltage vector of normal operation:

[0023] The common three-phase six switch topology three-phase six bridge arms have 8 kinds of voltage state combination, that is, 8 kinds of switch state, respectively corresponding to 8 basic voltage vectors, respectively: V0(000), V1(100), V2(110), V3(010), V4(011), V5(001), V6(101), V7(111), wherein V0(000), V7(111) is zero vector, the remaining six V1(100), V2(110), V3(010), V4(011), V5(001), V6(101) is effective vector, the function value "1" in the bracket indicates that the upper bridge arm switch of the phase is turned on, the function value "0" indicates that the lower bridge arm switch of the phase is turned on, the first function value indicates the switching state of A phase, the second function value indicates the switching state of B phase, and the third function value indicates the switching state of C phase;

[0024] Determine the basic voltage vector of each sector synthesized reference vector:

[0025] With the α axis as the reference, sequentially rotate 60° counterclockwise to obtain six sectors I, II, III, IV, V, VI, use basic voltage vectors V0(000), V1(100), V2(110), V7(111) to synthesize the reference vector in sector I, use basic voltage vectors V0(000), V2(110), V3(010), V7(111) to synthesize the reference vector in sector II, use basic voltage vectors V0(000), V3(010), V4(011), V7(111) to synthesize the reference vector in sector III, use basic voltage vectors V0(000), V4(011), V5(001), V7(111) to synthesize the reference vector in sector IV, use basic voltage vectors V0(000), V5(001), V6(101), V7(111) to synthesize the reference vector in sector V, and use basic voltage vectors V0(000), V6(101), V1(100), V7(111) to synthesize the reference vector in sector VI;

[0026] According to the basic voltage vectors of the reference vector of each sector and the seven-segment vector synthesis principle, the action order of the basic voltage vectors of each sector is obtained:

[0027] Sector I: V0(000) V1(100) V2(110) V7(111) V2(110) V1(100) V0

[0028] Sector II: V0(000) V3(010) V2(110) V7(111) V2(110) V3(010) V0(000), sector III: V0(000) V3(010) V4(011) V7(111) V4(011) V3(010) V0(000), sector IV: V0(000) V5(001) V4(011) V7(111) V4(011) V5(001) V0(000), sector V: V0(000) V5(001) V6(101) V7(111) V6(101) V5(001) V0(000), sector VI: V0(000) V1(100) V6(101) V7(111) V6(101) V1(100) V0(000);

[0029] Determine the action time of the basic voltage vectors of each sector:

[0030] Define T1, T2, T0 as the action time of two effective vectors and the zero vector in the basic voltage vectors of the synthesized reference vector in one period:

[0031]

[0032] Wherein, T sFor the sampling period, that is, in sector I, the action time of basic voltage vector V1 (100) is T1, the action time of V2 (110) is T2, the action time of V0 (000) is T0 / 2, and the action time of V7 (111) is T0 / 2; in sector II, the action time of basic voltage vector V2 (110) is T1, the action time of V3 (010) is T2, the action time of V0 (000) is T0 / 2, and the action time of V7 (111) is T0 / 2; in sector III, the action time of basic voltage vector V3 (010) is T1, the action time of V4 (011) is T2, the action time of V0 (000) is T0 / 2, and the action time of V7 (111) is T0 / 2; in sector IV, the action time of basic voltage vector V4 (011) is T1, the action time of V5 (001) is T2, the action time of V0 (000) is T0 / 2, and the action time of V7 (111) is T0 / 2; in sector V, the action time of basic voltage vector V5 (001) is T1, the action time of V6 (101) is T2, the action time of V0 (000) is T0 / 2, and the action time of V7 (111) is T0 / 2; in sector VI, the action time of basic voltage vector V6 (101) is T1, the action time of V1 (100) is T2, the action time of V0 (000) is T0 / 2, and the action time of V7 (111) is T0 / 2;

[0033] According to the action sequence of the basic voltage vector and the action time of the basic voltage vector, the action time of the IGBT power switch tube switching state is determined, 6-way PWM signals are generated, the IGBT power switch tube is controlled to be on and off, and the control of the normal three-phase motor driver is completed.

[0034] Further, (2) variable boost SVPWM control, according to the DC power supply condition, the variable boost ratio type three-phase six-switch topology is switched, the action time of each sector basic voltage vector is recalculated, and then according to the action sequence of the basic voltage vector and the action time of the basic voltage vector, the specific method is:

[0035] Determine the inductance discharge time and the inductance charging time:

[0036] The seven kinds of switching states corresponding to the basic voltage vectors V0 (000), V1 (100), V2 (110), V3 (010), V4 (011), V5 (001), and V6 (101) are inductance charging states, and the corresponding conduction time is the inductance charging time. The switching state corresponding to the basic voltage vector V7 (111) is the inductance discharge state, and the corresponding conduction time is the discharge time.

[0037] Define the duty cycle D:

[0038]

[0039] where T u is the inductor discharge time, T w is the inductor charging time, T s is the sampling period time;

[0040] Define the boost gain X:

[0041] When the inductor is charging, the capacitor is discharging to supply power to the back-end load, and when the inductor is discharging, the capacitor is charging to store energy. According to the inductor volt-second balance principle, the voltages of the two capacitors C f after boosting are determined within the sampling period:

[0042]

[0043] From the above formula, when the time proportion under the charging and discharging switch state is changed, the boost ratio can be changed. Now define the boost gain X as:

[0044]

[0045] Based on the boost control strategy, the action time of the zero vector is redistributed:

[0046] Changing the time of the basic voltage vector V7(111) in the inductor discharge state can change the boost ratio. Let the action time of the V7(111) state be T n , then the action time of V7(111) is:

[0047]

[0048] That is, the adjusted action time of each sector basic voltage vector is obtained. In sector I, the action time of the basic voltage vector V1(100) is T1, the action time of V2(110) is T2, and the action time of V0(000) is T0-T n , and the action time of V7(111) is T n ; in sector II, the action time of the basic voltage vector V2(110) is T1, the action time of V3(010) is T2, and the action time of V0(000) is T0-T n , and the action time of V7(111) is T n ; in sector III, the action time of the basic voltage vector V3(010) is T1, the action time of V4(011) is T2, and the action time of V0(000) is T0-T n , and the action time of V7(111) is T n ; in sector IV, the action time of the basic voltage vector V4(011) is T1, the action time of V5(001) is T2, and the action time of V0(000) is T0-Tn The action time of V7 (111) is T n ; in sector V, the action time of basic voltage vector V5 (001) is T1, the action time of V6 (101) is T2, and the action time of V0 (000) is T0-T n The action time of V7 (111) is T n ; in sector VI, the action time of basic voltage vector V6 (101) is T1, the action time of V1 (100) is T2, and the action time of V0 (000) is T0-T n The action time of V7 (111) is T n ;

[0049] According to the basic voltage vector action sequence and the basic voltage vector action time, the action time of the IGBT power switch tube switching state is determined, 6-way PWM signals are generated, the IGBT controls the on-off of the power switch tube, and the control of the variable boost ratio type three-phase motor driver is completed.

[0050] Further, in the fault-tolerant SVPWM control, the basic voltage vector when a single tube or single-phase fault is reconstructed, and a virtual vector is synthesized, and the specific method is:

[0051] The basic voltage vector when a single tube or single-phase fault is reconstructed:

[0052] After a single tube or single-phase fault occurs, the motor winding of the fault phase is connected to the capacitor midpoint through the opened bidirectional thyristor, and only the four power switch tubes IGBT of the upper and lower bridge arms of the remaining two non-fault phases normally work, and the boost type three-phase motor driver is controlled and operated by the four IGBT power switch tubes, there are four voltage state combinations, i.e. four switching states, which correspond to four basic voltage vectors, respectively: V1 (00), V2 (10), V3 (11), and V4 (01), and the four basic voltage vectors are all effective vectors; after a fault occurs in one of the A, B, and C phases, the four basic voltage vectors V1 (00), V2 (10), V3 (11), and V4 (01) are sequentially arranged in a clockwise direction in the plane, each adjacent vector is separated by 90°, and there are four sectors in the plane. In order to simplify the calculation of the reference vector after each phase fault, the positive direction of the coordinate axes α and β is defined as the positive direction of the basic voltage vectors V1 (00) and V2 (10), and the reference vector V ref The projection on the α, β axis is U α , U β ;

[0053] Synthesis of virtual vector, including virtual effective vector and virtual zero vector:

[0054] The virtual effective vector V 12, the basic voltage vector V2 (10) and V3 (11) synthesize the virtual effective vector V 23 , the basic voltage vector V3 (11) and V4 (01) synthesize the virtual effective vector V 34 , the basic voltage vector V4 (01) and V1 (00) synthesize the virtual effective vector V 41 , the synthesis principle is:

[0055]

[0056] The four basic voltage vectors are effective vectors, and the virtual vector V 12 , V 23 , V 34 , V 41 is an effective vector; the virtual zero vector needs to be selected from two of the four basic voltage vectors, and the synthesis principle is:

[0057]

[0058] Further, (3) in fault-tolerant SVPWM control, the acting vectors are selected to re-divide the 6 sectors, and the acting order and acting time of the acting vectors in each sector are determined, and the specific method is:

[0059] Re-divide the 6 sectors:

[0060] Take V1 (00) and V3 (11) in the four basic space vectors and the synthesized four virtual effective vectors V 12 , V 23 , V 34 , V 41 and the virtual zero vector V 00 as the acting vectors of the synthesized reference vectors, V1 (00), V3 (11), V 12 , V 23 , V 34 , V 41 The amplitude of the six acting vectors is equal, mutually symmetrical, and mutually different by 60° in space. Taking the α axis as the reference, rotate counterclockwise by 60° in turn to obtain six sectors I, II, III, IV, V, VI.

[0061] According to the seven-segment vector synthesis principle, determine the acting order of the acting vectors of the synthesized reference vectors in each sector:

[0062] First sector: V 00 V1 V 12 V 00 V 12 V1 V 00 ; second sector: V 00 V 23 V 12 V00 V 12 V 23 V 00 ; third sector: V 00 V 23 V3 V 00 V3 V 23 V 00 ; fourth sector: V 00 V 34 V3 V 00 V3 V 34 V 00 ; fifth sector: V 00 V 34 V 41 V 00 V 41 V 34 V 00 ; sixth sector: V 00 V1 V 41 V 00 V 41 V1 V 00 ;

[0063] Determine the action time of each sector action vector:

[0064] Define T x , T y , T z , respectively, the action time of two adjacent effective vectors and virtual zero vectors equivalent in a period:

[0065]

[0066] That is, the action vector of the first sector is V1, V 12 , V 00 , and the action time is T x , T y , T z ; The action vector of the second sector is V 12 , V 23 , V 00 , and the action time is T x , T y , T z ; The action vector of the third sector is V 23 , V3, V 00 , and the action time is T x , T y , T z ; The action vector of the fourth sector is V3, V 34 , V 00 , and the action time is T x , Ty , T z ; the action vector of the fifth sector is V 34 , V 41 , V 00 , and the action time is T x , T y , T z ; the action vector of the sixth sector is V 41 , V 00 , and the action time is T x , T y , T z .

[0067] Further, (3) fault-tolerant SVPWM control, the action time of the virtual vector is distributed to the four basic voltage vectors, and the action order and action time of the basic voltage vectors of the synthesized reference vector of each sector are determined, and the specific method is:

[0068] The action time of the virtual vector is distributed to the four basic voltage vectors, and the action time of the basic voltage vector of the synthesized reference vector of each sector is determined:

[0069] According to the synthesis principle of the virtual effective vector and the virtual zero vector, the action time of the virtual vector is redistributed to the four basic voltage vectors, and the time of the four basic voltage vectors V1 (00), V2 (10), V3 (11), and V4 (01) is defined as T1, T2, T3, and T4:

[0070] The basic voltage vectors used by the first sector are V1 (00), V2 (10), and V3 (11), and the corresponding action time is

[0071]

[0072] The basic voltage vectors used by the second sector are V1 (00), V2 (10), and V3 (11), and the corresponding action time is

[0073]

[0074] The basic voltage vectors used by the third sector are V1 (00), V2 (10), and V3 (11), and the corresponding action time is

[0075]

[0076] The basic voltage vectors used by the fourth sector are V1 (00), V4 (01), and V3 (11), and the corresponding action time is

[0077]

[0078] The basic voltage vectors used by the fifth sector are V1(00), V4(01) and V3(11) respectively, and the corresponding action time is

[0079]

[0080] The basic voltage vectors used by the sixth sector are V1(00), V4(01) and V3(11) respectively, and the corresponding action time is

[0081]

[0082] The action time of the basic voltage vector is determined:

[0083] In consideration of the minimum switching loss, according to the five-segment vector synthesis principle, the action sequence of the basic voltage vector of the boost-type three-phase four-switch topology is determined as:

[0084] The first, second and third sectors: V1(00), V2(10), V3(11), V2(10), V1(00)

[0085] The fourth, fifth and sixth sectors: V1(00), V4(01), V3(11), V4(01), V1(00).

[0086] According to the action sequence of the basic voltage vector and the action time of the basic voltage vector, the action time of the IGBT power switch tube switching state is determined, 4-way PWM signals are generated to control the on-off of the IGBT power switch tube, and the fault-tolerant control of the boost-type motor driver is completed.

[0087] Further, according to the action sequence and action time of the basic voltage vector, the action time of the IGBT power switch tube switching state is determined, PWM signals are generated to control the on-off of the IGBT power switch tube, and the control of the normal three-phase motor driver is completed, and the specific method is:

[0088] According to the action sequence, action time and switching point of the IGBT power switch tube conduction time of the basic voltage vector, the action time of the IGBT power switch tube switching state is determined, the DPWM technology is adopted, the action time of the IGBT power switch tube switching state is modulated with a triangular carrier whose frequency is the switching frequency of the IGBT power switch tube, at the same time, the on-off time of the IGBT power switch tube is added with a dead time, PWM signals are generated to control the on-off of the IGBT power switch tube, and the control of the multi-working-state three-phase motor driver is completed.

[0089] A control system of a multi-working-state three-phase motor driver, which implements the control method of the multi-working-state three-phase motor driver, realizes the control of the driver in different working states.

[0090] The application discloses a computer device, which comprises a memory, a processor and a computer program stored in the memory and executable on the processor, and when the processor executes the computer program, the computer program implements the multi-working state three-phase motor driver control method.

[0091] The application discloses a computer readable storage medium, which stores a computer program, and when the processor executes the computer program, the computer program implements the variable boost ratio type three-phase motor driver fault-tolerant control method.

[0092] Compared with the prior art, the application has the following advantages: 1) the proposed topology combines the ordinary six-switch driver and the boost topology by only adding bidirectional thyristor switches, and the new driver can realize multiple working states; 2) the single-stage boost type driver fault-tolerant function is realized by changing the topology and the control algorithm, and the size, cost, weight and complexity of the system are reduced; 3) after switching the boost topology, the boost ratio is changed by changing the action time of the zero vector, and a variable boost ratio type motor drive control method is realized; 4) in the fault-tolerant state, the DC side voltage is raised by the new six-sector division SVPWM algorithm, the rated power is not reduced, and the system can still operate stably when the four-switch works; and 5) the fault-tolerant control can be completed for all single-pipe open circuit faults, all single-phase open circuit faults, all single-pipe short circuit faults and all single-phase short circuit faults, and the control difficulty is relatively small. BRIEF DESCRIPTION OF DRAWINGS

[0093] Figure 1 It is a multi-working state three-phase motor driver topology.

[0094] Figure 2 It is a multi-working state three-phase motor driver topology control block diagram.

[0095] Fig. 3(a) is a schematic diagram of an ordinary three-phase six-switch and boost three-phase six-switch inverter space vector circle; and Fig. 3(b) is a schematic diagram of a six-sector division vector circle of a boost three-phase four-switch fault-tolerant topology when a fault occurs.

[0096] Figure 4 It is a variable boost ratio type three-phase six-motor driver topology and current flow direction diagram.

[0097] Figure 5 It is a boost type three-phase four-switch motor driver topology and current flow direction diagram when an A-phase fault occurs.

[0098] Fig. 6(a) is a schematic diagram of motor three-phase current when the boost topology is in normal operation; Fig. 6(b) is a schematic diagram of motor speed when the boost topology is in normal operation; Fig. 6(c) is a schematic diagram of motor electromagnetic torque when the boost topology is in normal operation; Fig. 6(d) is a schematic diagram of DC power supply voltage U In and DC side capacitor voltage U dc ; Fig. 6(e) is a schematic diagram of DC power supply voltage U In and DC side capacitor voltage U dc when the boost topology is in normal operation after changing the boost ratio;

[0099] Fig. 7(a) is a schematic diagram of motor three-phase current when the A-phase switch tube is in fault operation; Fig. 7(b) is a schematic diagram of motor electromagnetic torque when the A-phase switch tube is in fault operation; Fig. 7(c) is a schematic diagram of motor speed when the A-phase switch tube is in fault operation.

[0100] Fig. 8(a) is a schematic diagram of motor three-phase current when the A-phase switch tube is in fault tolerant operation; Fig. 8(b) is a schematic diagram of motor electromagnetic torque when the A-phase switch tube is in fault tolerant operation; Fig. 8(c) is a schematic diagram of motor speed when the A-phase switch tube is in fault tolerant operation; Fig. 8(d) is a schematic diagram of DC power supply voltage U In and DC side capacitor voltage U dc when the A-phase switch tube is in fault tolerant operation. DETAILED DESCRIPTION

[0101] In order to make the purposes, technical solutions and advantages of the present application clearer, the present application is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application.

[0102] Figure 1 is a topology diagram of a motor driver with fault-tolerant function and multiple working states, which is composed of a three-phase six-switch two-level drive converter, a boost topology and several switch devices. Each phase of the three-phase six-switch has two bridge arms, and the three phases have six bridge arms in total. The six bridge arms are composed of six IGBT power switch tubes S1-S6 and six diodes D1-D6 connected in parallel with the power switch tubes. Each of the upper and lower bridge arms of the A, B and C three-phase is connected in series with a fast fuse, and a total of six fast fuses F1-F6 are used. The DC power supply U In positive electrode is connected to the bidirectional thyristor S7, and then connected to the upper bridge arms of the A-phase, B-phase and C-phase of the three-phase bridge arms respectively. The DC power supply U In negative electrode is connected to the lower bridge arms of the A-phase, B-phase and C-phase of the three-phase bridge arms. The midpoints of the upper and lower bridge arms of the A, B and C three-phase are connected to the a, b and c phase windings of the permanent magnet synchronous motor respectively. a , i b , i cThe current flowing through the a, b, c phase winding ends of the motor.

[0103] Two capacitors C f The positive pole of the series connection of the series capacitors is connected to the bidirectional thyristor S8, and then connected to the bidirectional thyristor S7, and the negative pole of the series connection of the series capacitors is connected to the DC power supply U In The negative poles are connected, and the midpoints of the two capacitors C f are connected to the midpoints of the upper and lower bridge arms of the three-phase A, B, and C through three bidirectional thyristors TR1, TR2, and TR3, and then connected to the a, b, and c three-phase winding ends of the permanent magnet synchronous motor; the DC power supply U In The positive pole is first connected to the bidirectional thyristor S9, and then connected to the inductor L1, the other end of the inductor L1 is connected to the positive poles of the diodes D7, D8, and D9, and the negative poles of the diodes D7, D8, and D9 are respectively connected to the a, b, and c three-phase winding ends.

[0104] Figure 2 is a control block diagram of a multi-working-state motor driver with fault-tolerant function. When normally running, the bidirectional thyristor S7 is opened, the bidirectional thyristor S8 and the bidirectional thyristor S9 are closed, and the normal three-phase six-switch topology is run; when the DC power supply cannot meet the full power running of the motor, the bidirectional thyristor S7 is closed, the bidirectional thyristor S8 and the bidirectional thyristor S9 are opened, and the topology is switched from the normal three-phase six-switch topology to the variable boost ratio type three-phase six-switch topology; when a short circuit fault of the IGBT power switch tube of a bridge arm of the driver causes the corresponding fast fuse to melt, or a direct open circuit fault occurs, the bidirectional thyristor S7 is closed, the bidirectional thyristor S8 and the bidirectional thyristor S9 are opened, and the bidirectional thyristor TR1, TR2, or TR3 connected to the corresponding phase of the opened IGBT power switch tube is opened, and the boost type three-phase four-switch topology structure is switched.

[0105] The multi-working-state three-phase motor driver adopts a speed outer ring and a current inner ring double closed loop operation, wherein the speed ring inputs a PI regulator with the difference between the motor speed obtained by collection and the reference speed, and outputs a q-axis current reference value; the current ring takes zero d-axis as a d-axis current reference value, and then collects three-phase currents and motor electrical angles, and obtains d-axis and q-axis currents through Park transformation, and inputs a PI regulator with the difference between the d-axis and q-axis currents and the d-axis and q-axis current reference values respectively, and outputs d-axis and q-axis voltage reference values, which are obtained through Park inverse transformation to obtain α-axis and β-axis voltage reference values U α , U β ; U α , U β are input to normal SVPWM control modules, variable boost SVPWM control modules, and fault-tolerant SVPWM control modules corresponding to different working states to generate signals for controlling the on-off of the IGBT gate, and the gate signals are input to the topologies corresponding to different working states.

[0106] For the above line topology and its control block diagram, the multi-working-state three-phase motor driver and its control method of the application comprises the following:

[0107] (1) Normal SVPWM control, the specific method is:

[0108] Step 1, determine the basic voltage vector in normal operation:

[0109] Fig. 3(a) is a schematic diagram of the space vector circle of the ordinary three-phase six-switch and boost three-phase six-switch inverter, the three-phase six-switch topology has eight voltage state combinations, i.e. eight switch states, which correspond to eight space voltage vectors respectively, i.e. V0(000), V1(100), V2(110), V3(010), V4(011), V5(001), V6(101), and V7(111), wherein V0(000) and V7(111) are zero vectors, and the remaining six V1(100), V2(110), V3(010), V4(011), V5(001), and V6(101) are effective vectors, the function value "1" in the brackets indicates that the upper bridge switch tube of the phase is turned on, the function value "0" indicates that the lower bridge switch tube of the phase is turned on, the first function value indicates the switch state of the A phase, the second function value indicates the switch state of the B phase, and the third function value indicates the switch state of the C phase;

[0110] Step 2, determine the basic voltage vector of the synthesized reference vector in each sector:

[0111] Take the α axis as the reference, and rotate counterclockwise by 60° in turn to obtain six sectors I, II, III, IV, V, and VI, the basic voltage vectors V0(000), V1(100), V2(110), and V7(111) are used to synthesize the reference vector in the sector I, the basic voltage vectors V0(000), V2(110), V3(010), and V7(111) are used to synthesize the reference vector in the sector II, the basic voltage vectors V0(000), V3(010), V4(011), and V7(111) are used to synthesize the reference vector in the sector III, the basic voltage vectors V0(000), V4(011), V5(001), and V7(111) are used to synthesize the reference vector in the sector IV, the basic voltage vectors V0(000), V5(001), V6(101), and V7(111) are used to synthesize the reference vector in the sector V, and the basic voltage vectors V0(000), V6(101), V1(100), and V7(111) are used to synthesize the reference vector in the sector VI;

[0112] Step 3, according to the basic voltage vector of the synthesized reference vector in each sector and the seven-segment vector synthesis principle, the action order of the basic voltage vector in each sector is shown in Table 1:

[0113] Table 1 Sector basic voltage vector action sequence table

[0114] Sector number Basic voltage vector action sequence I <![CDATA[V0(000)V1(100)V2(110)V7(111)V2(110)V1(100)V0(000)]]> II <![CDATA[V0(000)V3(010)V2(110)V7(111)V2(110)V3(010)V0(000)]]> III <![CDATA[V0(000)V3(010)V4(011)V7(111)V4(011)V3(010)V0(000)]]> IV <![CDATA[V0(000)V5(001)V4(011)V7(111)V4(011)V5(001)V0(000)]]> V <![CDATA[V0(000)V5(001)V6(101)V7(111)V6(101)V5(001)V0(000)]]> VI <![CDATA[V0(000)V1(100)V6(101)V7(111)V6(101)V1(100)V0(000)]]>

[0115] Step 4, determine the action time of each sector basic voltage vector:

[0116] Define T1, T2, T0 as the action time of two effective vectors and zero vector of the basic voltage vector of the synthesized reference vector in a period:

[0117]

[0118] Where, T s is the sampling period, the action time of each sector basic voltage vector is shown in Table 2:

[0119] Table 2 Basic voltage vector action time table

[0120]

[0121]

[0122] Step 5, according to the basic voltage vector action sequence and the action time of the basic voltage vector, determine the action time of the IGBT power switch tube switching state, generate 6-way PWM signal, control the on-off of IGBT power switch tube, complete the control of normal three-phase motor driver.

[0123] (2) variable boost SVPWM control, according to the DC power supply condition, switch the variable boost ratio type three-phase six switch topology, recalculate the action time of each sector basic voltage vector, then according to the basic voltage vector action sequence and the basic voltage vector action time, the specific method is:

[0124] Step 1, determine the inductance discharge time and inductance charging time:

[0125] The seven kinds of switching states corresponding to the basic voltage vectors V0(000), V1(100), V2(110), V3(010), V4(011), V5(001), V6(101) are inductance charging state, and the corresponding conduction time is inductance charging time. The switching state corresponding to the basic voltage vector V7(111) is inductance discharge state, and the corresponding conduction time is discharge time;

[0126] Step 2, define the duty cycle D:

[0127]

[0128] In the formula, Tu is the inductance discharge time, Tw is the inductance charging time, and Ts is the sampling period time;

[0129] Step 3, define the boost gain X:

[0130] When the inductor is charging, the capacitor is discharging to supply power to the back-end load, when the inductor is discharging, the capacitor is charging to store energy, and according to the inductor volt-second balance principle in the sampling period, the voltage between the two capacitors Cf after boosting is:

[0131]

[0132] From the above formula, when the time ratio of the charging and discharging switch state is changed, the boost ratio can be changed, and the boost gain X is defined as:

[0133]

[0134] Step 4, based on the boost control strategy, re-allocate the action time of zero vector:

[0135] Change the basic voltage vector V7(111) time of the inductor discharging state, which can change the boost ratio, and the action time of V7(111) state is T n , then the action time of V7(111) is:

[0136]

[0137] Determine:

[0138] That is, the action time of the adjusted basic voltage vector of each sector is shown in Table 3:

[0139] Table 3 Modulated basic voltage vector action time table

[0140]

[0141] Step 5, according to the basic voltage vector action sequence and the basic voltage vector action time, determine the action time of the IGBT power switch tube switch state, generate 6-way PWM signal, IGBT control power switch tube on-off, complete the control of variable boost ratio type three-phase motor driver.

[0142] (3) Fault-tolerant SVPWM control, reconstruct the basic voltage vector when a single tube or single-phase fault occurs, and synthesize a virtual vector, the specific method is:

[0143] Step 1, reconstruct the basic voltage vector when a single tube or single-phase fault occurs:

[0144] When A phase fails, it is controlled by the four switches of the upper and lower bridge arms of B and C phases, when B phase fails, it is controlled by the four switches of the upper and lower bridge arms of C and A phases, and when C phase fails, it is controlled by the four switches of the upper and lower bridge arms of A and B phases. Since the fault includes open circuit fault and short circuit fault, the action of the bidirectional thyristor corresponding to the open circuit fault is shown in Table 4:

[0145] Table 4 Bidirectional thyristor action corresponding to different switch tube open circuit faults

[0146]

[0147]

[0148] When the switch tube has a short circuit fault, the corresponding switch tube fuse is blown, converting the short circuit fault into an open circuit fault, and the bidirectional thyristor and the fast fuse corresponding to the short circuit fault act as shown in Table 5;

[0149] Table 5 Bidirectional thyristor and fast fuse action corresponding to different switch tube short circuit faults

[0150]

[0151] After a single tube or single phase fault occurs, the motor winding of the fault phase is connected to the capacitor midpoint through the opened bidirectional thyristor, and only the four power switch tubes IGBT of the upper and lower bridge arms of the remaining two non-fault phases work normally. Taking the A phase fault as an example, as shown in Figure 5 , the boost three-phase motor driver is controlled to operate by the four switch tubes IGBT, and there are four voltage state combinations, i.e. four switching states, corresponding to four basic voltage vectors, respectively: V1(00), V2(10), V3(11), and V4(01), and the four basic voltage vectors are all effective vectors. The states of the switch tubes corresponding to different fault phases are shown in Table 6:

[0152] Table 6 States of switch tubes corresponding to different fault phases

[0153]

[0154] In the table, Sa, Sb, and Sc represent the switching states of the power devices of the A, B, and C phase bridge arms, respectively, and the function value "1" indicates that the upper bridge arm switch tube is turned on, and the function value "0" indicates that the lower bridge arm switch tube is turned on.

[0155] Since a fault occurs in one of the A, B, and C phases, the four basic voltage vectors V1(00), V2(10), V3(11), and V4(01) are arranged in a clockwise direction in the plane, and each adjacent vector is separated by 90°. There are four sectors in the plane. In order to simplify the calculation of the reference vector after each phase fault, the positive directions of the coordinate axes a and β are set as the positive directions of the basic voltage vectors V1(00) and V2(10), and the reference vector V ref The projections on the a and β axes are U α , and U β ;

[0156] Step 2, synthesis of virtual vector, including virtual effective vector and virtual zero vector:

[0157] Synthesis of virtual effective vector V 12 by basic voltage vector V2(10), V3(11) 23 Synthesis of virtual effective vector V 34 by basic voltage vector V4(01), V1(00) 41 The synthesis principle is:

[0158]

[0159] Four basic voltage vectors are effective vectors, virtual vectors V 12 , V 23 , V 34 , V 41 are effective vectors, and virtual zero vector needs to be selected by synthesizing two of the four basic voltage vectors, and the synthesis principle is:

[0160]

[0161] Select the action vector to re-divide the 6 sectors, and determine the action order and action time of the action vector of each sector, the specific method is:

[0162] Step 3, re-divide the 6 sectors:

[0163] Take V1(00), V3(11) in the four basic space vectors and the synthesized four virtual effective vectors V 12 , V 23 , V 34 , V 41 and virtual zero vector V 00 as the action vectors of the synthesized reference vectors, V1(00), V3(11), V 12 , V 23 , V 34 , V 41 The amplitude of the six action vectors is equal, mutually symmetrical, and mutually different by 60° in space, and taking the α axis as the reference, they are rotated counterclockwise by 60° in turn, to get 6 sectors I, II, III, IV, V, VI;

[0164] Step 4, according to the seven-segment vector synthesis principle, determine the action order of the action vector of the synthesis reference vector of each sector, the action order of the action vector of each sector is shown in Table 7;

[0165] Table 7 Action order table of action vector

[0166]

[0167]

[0168] Step 5, determine the action time of each sector action vector:

[0169] Define T x , T y , T z are the action time of two adjacent effective vectors and virtual zero vector respectively in a period:

[0170]

[0171] Where Ts is the sampling period;

[0172] That is, the action time of each sector action vector is shown in Table 8:

[0173] Table 8 Action vector action time table

[0174]

[0175] The action time of the virtual vector is allocated to the four basic voltage vectors, and the action order and action time of the basic voltage vectors of the synthesized reference vector of each sector are determined, and the specific method is:

[0176] Step 6, the action time of the virtual vector is allocated to the four basic voltage vectors, and the action time of the basic voltage vectors of the synthesized reference vector of each sector is determined:

[0177] According to the synthesis principle of virtual effective vector and virtual zero vector, the action time of the virtual vector is re-allocated to the four basic voltage vectors, and the time of V1(00), V2(10), V3(11), V4(01) four basic voltage vectors is defined as T1, T2, T3, T4 respectively, and the basic voltage vector action time of each sector is shown in Table 9:

[0178] Table 9 Basic voltage vector action time of each sector

[0179]

[0180] Step 7, determine the action time of the basic voltage vector:

[0181] Considering the minimum switching loss, according to the five-segment vector synthesis principle, the action order of the basic voltage vector of the boost type three-phase four-switch topology is determined as:

[0182] First, second, third sector: V1(00), V2(10), V3(11), V2(10), V1(00)

[0183] Fourth, fifth, sixth sector: V1 (00), V4 (01), V3 (11), V4 (01), V1 (00);

[0184] Step 8, according to the basic voltage vector action sequence and the action time of the basic voltage vector, the action time of the IGBT power switch tube switching state is determined, 4-way PWM signals are generated, the IGBT power switch tube is controlled to be turned on and off, and the fault-tolerant control of the boost type motor driver is completed.

[0185] Wherein, according to the basic voltage vector action sequence and the action time, the action time of the IGBT power switch tube switching state is determined, PWM signals are generated, the IGBT power switch tube is controlled to be turned on and off, and the control of the normal three-phase motor driver is completed, and the specific method is:

[0186] According to the basic voltage vector action sequence, the action time and the switching point of the IGBT power switch tube conduction time, the action time of the IGBT power switch tube switching state is determined, the DPWM technology is used, the IGBT power switch tube switching state action time is modulated with a triangular carrier with the frequency of the IGBT power switch tube switching frequency, at the same time, the IGBT power switch tube turn-on and turn-off time is added to the dead time, PWM signals are generated, the IGBT power switch tube is controlled to be turned on and off, and the control of the multi-working-state three-phase motor driver is completed.

[0187] A multi-working-state three-phase motor driver and a control system thereof are used to realize the multi-working-state three-phase motor driver control method.

[0188] A computer device includes a memory, a processor and a computer program stored on the memory and executable on the processor, and when the processor executes the computer program, the multi-working-state three-phase motor driver control method is realized.

[0189] A computer readable storage medium has a computer program stored thereon, and when the computer program is executed by a processor, the variable boost ratio type three-phase motor driver fault-tolerant control method is realized.

[0190] The present application switches the topology to different working states according to different situations, and simultaneously switches the corresponding control algorithm, in the fault state, by acquiring fault information, changing the corresponding system hardware topology and control algorithm, the state recovery in the condition of all single tube, same bridge arm double tube open circuit fault or short circuit fault can be realized, the high power quality, full load fault-tolerant operation is achieved, and the reliability and stability of the motor driver system are improved.

[0191] Example 1

[0192] The embodiment is when the DC side power supply is insufficient, the DC voltage is reduced, the power is reduced, and the operation requirement cannot be met. The topology is switched to the variable boost ratio three-phase six-switch topology, the DC side voltage is raised, and the boost effect is shown in FIG. 6(d). When the input DC power supply U In The voltage is 100V, the DC side capacitor voltage U dc can be raised to 250V, and the fluctuation of several volts is a normal capacitor charging and discharging phenomenon. The motor three-phase current in normal operation after the topology is changed is shown in FIG. 6(a), the current waveform is a normal sinusoidal current waveform without any distortion. The motor electromagnetic torque in normal operation after the topology is changed is shown in FIG. 6(b), the electromagnetic torque is about 15N*m. The motor speed in normal operation after the topology is changed is shown in FIG. 6(c), the speed is 60rad / s. It can be seen from the operation states of the torque and the speed that the motor runs smoothly. FIG. 6(e) shows that the boost factor can change the boost ratio by control. When the input DC power supply U In The voltage is 100V, the DC side capacitor voltage U dc can be raised to 340V. It can be seen from the above that the variable boost ratio three-phase six-switch driver system can cope with the unstable operation of the system caused by different degrees of DC power voltage drop.

[0193] Embodiment 2

[0194] The embodiment is when a single tube or single-phase fault occurs, the topology is switched to the boost three-phase four-switch fault-tolerant topology, and the fault-tolerant control method is operated. Taking the A-phase switch tube fault as an example, FIG. 7(a) is the motor three-phase current after the A-phase switch tube fault, from the figure, it can be seen that the three-phase current amplitude increases sharply, the waveform is not a sinusoidal current waveform, and the phenomenon of asymmetry and distortion occurs. FIG. 7(b) is the motor electromagnetic torque when the A-phase fault is operated, from the figure, it can be seen that the motor electromagnetic torque oscillates sharply. FIG. 7(c) is the motor speed when the A-phase fault is operated, from the figure, it can be seen that the speed fluctuates sharply, and the motor is in an out-of-control state at this time, and the entire system is in a collapse state.

[0195] The motor three-phase current in operation after the fault-tolerant topology is switched is shown in FIG. 8(a), from the figure, it can be seen that the three-phase current basically recovers to the sinusoidal waveform state in normal operation. The motor electromagnetic torque in operation after the fault-tolerant topology is switched is shown in FIG. 8(b), the electromagnetic torque also recovers to the state in normal operation, the electromagnetic torque is about 15N*m, and the motor runs smoothly. The motor speed in operation after the fault-tolerant topology is switched is shown in FIG. 8(c), the motor speed recovers to the state in normal operation, the speed is 60rad / s. The DC power supply voltage U In and the DC side capacitor voltage U dc are shown in FIG. 8(d), when the input DC power supply U InThe DC side capacitor voltage U is 100V dc It can be raised to about 250V.

[0196] From the above results, it can be seen that the fault-tolerant control method of the variable boost ratio type three-phase six-switch motor driver can play a good control role on the current, speed, torque and DC side capacitor voltage after the failure of a single tube or single phase of the driver, and enhances the reliability of the motor driver system, so that the system can continue to operate stably.

[0197] The above two embodiments show that the method proposed in the application can switch different topologies and realize the operation of multiple working states under different conditions of the motor driver system.

[0198] The technical features of the above embodiments can be combined arbitrarily, and in order to make the description concise, all possible combinations of the technical features in the above embodiments are not described, however, as long as the combination of the technical features does not exist contradictory, it should be considered as the scope of the present application.

[0199] The above embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the present application. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A multi-operating state three-phase motor drive, characterized by: Composed of three-phase six-switch two-level inverter, additional boost topology and switching devices for topology reconfiguration, wherein: (1) Three-phase six-switch two-level inverter: Each phase of the three-phase six-switch two-level drive is composed of upper and lower bridge arms, and the three phases A, B and C share six bridge arms, which are composed of six IGBT power switches S1-S6 and six diodes D1-D6 connected in parallel with the power switches. Each of the upper and lower bridge arms of the three phases A, B and C is connected in series with a fast fuse, and a total of six fast fuses F1-F6 are used. In The positive electrode is first connected to the bidirectional thyristor S7, and then connected to the upper bridge arms of the three-phase bridge arms A, B and C, respectively. The DC power supply U In The negative electrode is connected to the lower bridge arms of the three-phase bridge arms A, B and C, respectively. The midpoints of the upper and lower bridge arms of the three phases A, B and C are connected to the a, b and c phase windings of the permanent magnet synchronous motor, respectively. a b c is the current flowing through the a, b and c phase windings of the motor.​​ (2) Additional boost topology and switching devices for topology reconfiguration: Two capacitors C f The positive pole of the series connection of the capacitors is connected to the bidirectional thyristor S8, and then to the bidirectional thyristor S7, and the negative pole of the series connection of the capacitors is connected to the DC power supply U In The negative poles are connected, and the midpoints of the two capacitors C f are connected to the midpoints of the upper and lower bridge arms of the three-phase A, B and C through three bidirectional thyristors TR1, TR2 and TR3, and then to the a, b and c three-phase winding ends of the permanent magnet synchronous motor; the DC power supply U In The positive pole is first connected to the bidirectional thyristor S9, and then to the inductor L1, the other end of the inductor L1 is connected to the positive poles of the diodes D7, D8 and D9, and the negative poles of the diodes D7, D8 and D9 are respectively connected to the a, b and c three-phase winding ends.

2. The multi-operating state three-phase motor drive of claim 1, wherein, When normal operation, bidirectional thyristor S7 is opened, bidirectional thyristor S8 and bidirectional thyristor S9 are closed, and the three-phase six-switch topology is operated; When the DC power supply cannot meet the full power operation of the motor, bidirectional thyristor S7 is closed, bidirectional thyristor S8 and bidirectional thyristor S9 are opened, and the topology is switched from the three-phase six-switch topology to the variable boost ratio three-phase six-switch topology; When the IGBT power switch tube of a certain bridge arm of the driver has a short-circuit fault corresponding to the blown fuse or a direct open-circuit fault, bidirectional thyristor S7 is closed, bidirectional thyristor S8 and bidirectional thyristor S9 are opened, and the bidirectional thyristor TR1, TR2 or TR3 connected to the fault IGBT power switch tube of the corresponding phase is opened, and the boost three-phase four-switch topology structure is switched.

3. The multi-operating state three-phase motor drive of claim 2, wherein, The multi-working state three-phase motor driver adopts double closed loop operation of speed outer ring and current inner ring. The speed ring inputs PI regulator by difference between motor speed obtained by collection and reference speed, and outputs q-axis current reference value. The current ring takes zero d-axis as d-axis current reference value, collects three-phase current and motor electric angle, obtains d-axis and q-axis current by Park transformation, inputs PI regulator by difference between d-axis and q-axis current reference value respectively, and outputs d-axis and q-axis voltage reference value. The α-axis and β-axis voltage reference value U α 、 β are obtained by Park inverse transformation. α 、 β are input to normal SVPWM control module, variable boost SVPWM control module and fault-tolerant SVPWM control module corresponding to different working states to generate signal for controlling on-off of IGBT gate, and the gate signal is input to topology corresponding to different working states.

4. A control method of a multi-operating state three-phase motor driver, characterized by, The multi-working-state three-phase electric driver based on any one of claims 1-3 is controlled, comprising: (1) Normal SVPWM control When normal operation, bidirectional thyristor S7 is opened, bidirectional thyristor S8 and bidirectional thyristor S9 are closed, and the three-phase six-switch topology is operated, the normal SVPWM control first determines the basic voltage vector of each sector of the three-phase six-switch topology when normal operation and the action sequence and action time of the basic voltage vector, then determines the action time of the IGBT power switch tube switching state according to the basic voltage vector action sequence and action time, generates 6 PWM signals, controls the on-off of the IGBT power switch tube, and completes the control of the normal three-phase motor driver; (2) Variable boost SVPWM control When the direct current power supply cannot meet the full power operation of the motor, the bidirectional thyristor S7 is closed, the bidirectional thyristor S8 and the bidirectional thyristor S9 are opened, the variable boost ratio type three-phase six-switch topology is switched, the energy of the direct current power supply U In is fed back to the capacitor C f at the front end, and the boosting effect is realized, the variable boost SVPWM control first determines the inductance discharge time and the inductance charge time, defines the duty ratio and the boost gain, then recalculates the action time of each sector basic voltage vector based on the boost control strategy, then determines the action time of the IGBT power switch tube switching state according to the basic voltage vector action sequence and the action time, generates 6-way PWM signals, controls the on-off of the IGBT power switch tube, and completes the control of the variable boost ratio type three-phase motor driver. (3) Fault-tolerant SVPWM control When the power switch tube of a certain bridge arm of the driver has a short-circuit fault corresponding to the blown fuse or a direct open-circuit fault, the boost three-phase four-switch topology is switched, the fault-tolerant SVPWM control uses a six-switch modulation algorithm, first reconfigures the basic voltage vector when a single tube or single-phase fault occurs, and synthesizes a virtual vector; then selects the action vector to redivide the 6 sectors, and determines the action sequence and action time of the action vector of each sector of the synthesized reference vector; then the action time of the virtual vector is distributed to the four basic voltage vectors, and the action sequence and action time of the basic voltage vector of each sector of the synthesized reference vector are determined; finally, the action time of the IGBT power switch tube switching state is determined according to the basic voltage vector action sequence and action time, thereby generating 4 PWM signals to control the on-off of the IGBT power switch tube and complete the fault-tolerant control of the boost motor driver.

5. The control method of a multi-operating state three-phase motor driver according to claim 4, characterized by, (1) Normal SVPWM control, the specific method is: Determine the basic voltage vector when normal operation: The three-phase six-switch topology has eight voltage state combinations, i.e. eight switch states, which correspond to eight basic voltage vectors, respectively, as follows: V0(000), V1(100), V2(110), V3(010), V4(011), V5(001), V6(101), and V7(111), wherein V0(000) and V7(111) are zero vectors, and the remaining six, V1(100), V2(110), V3(010), V4(011), V5(001), and V6(101), are effective vectors; the function value "1" in the brackets indicates that the upper bridge arm switch is turned on, and the function value "0" indicates that the lower bridge arm switch is turned on; the first function value indicates the switch state of phase A, the second function value indicates the switch state of phase B, and the third function value indicates the switch state of phase C; Determine the basic voltage vectors of the synthesized reference vectors of each sector: Take the alpha axis as the reference, and rotate counterclockwise by 60° in turn to obtain six sectors I, II, III, IV, V, and VI; in sector I, the basic voltage vectors V0(000), V1(100), V2(110), and V7(111) are used to synthesize the reference vector, in sector II, the basic voltage vectors V0(000), V2(110), V3(010), and V7(111) are used to synthesize the reference vector, in sector III, the basic voltage vectors V0(000), V3(010), V4(011), and V7(111) are used to synthesize the reference vector, in sector IV, the basic voltage vectors V0(000), V4(011), V5(001), and V7(111) are used to synthesize the reference vector, in sector V, the basic voltage vectors V0(000), V5(001), V6(101), and V7(111) are used to synthesize the reference vector, and in sector VI, the basic voltage vectors V0(000), V6(101), V1(100), and V7(111) are used to synthesize the reference vector; According to the basic voltage vectors of the synthesized reference vectors of each sector and the seven-segment vector synthesis principle, the action order of the basic voltage vectors of each sector is obtained: Sector I: V0(000) V1(100) V2(110) V7(111) V2(110) V1(100) V0(000), Sector II: V0(000) V3(010) V2(110) V7(111) V2(110) V3(010) V0(000), Sector III: V0(000) V3(010) V4(011) V7(111) V4(011) V3(010) V0(000), Sector IV: V0(000) V5(001) V4(011) V7(111) V4(011) V5(001) V0(000), Sector V: V0(000) V5(001) V6(101) V7(111) V6(101) V5(001) V0(000), Sector VI: V0(000) V1(100) V6(101) V7(111) V6(101) V1(100) V0(000); Determine the action time of each sector basic voltage vector: Define T1, T2, T0 as the action time of two effective vectors and zero vector in the basic voltage vector of the synthesized reference vector in a period: wherein T s is the sampling period, i.e. the time of action of the fundamental voltage vector V1 (100) in sector I is T1, of V2 (110) is T2, of V0 (000) is T0 / 2, of V7 (111) is T0 / 2; the time of action of the fundamental voltage vector V2 (110) in sector II is T1, of V3 (010) is T2, of V0 (000) is T0 / 2, of V7 (111) is T0 / 2; the time of action of the fundamental voltage vector V3 (010) in sector III is T1, of V4 (011) is T2, of V0 (000) is T0 / 2, of V7 (111) is T0 / 2; the time of action of the fundamental voltage vector V4 (011) in sector IV is T1, of V5 (001) is T2, of V0 (000) is T0 / 2, of V7 (111) is T0 / 2, the time of action of the fundamental voltage vector V5 (001) in sector V is T1, of V6 (101) is T2, of V0 (000) is T0 / 2, of V7 (111) is T0 / 2, the time of action of the fundamental voltage vector V6 (101) in sector VI is T1, of V1 (100) is T2, of V0 (000) is T0 / 2, of V7 (111) is T0 / 2;U α , U β are the voltage reference values on the α, β axes; According to the action sequence of the basic voltage vector and the action time of the basic voltage vector, the action time of the IGBT power switch tube switching state is determined, 6-way PWM signals are generated to control the on-off of the IGBT power switch tube, and the control of the normal three-phase motor driver is completed.

6. The control method of a multi-operating state three-phase motor drive according to claim 5, characterized by, (2) Variable boost SVPWM control, according to the DC power supply condition, switch the variable boost ratio type three-phase six-switch topology, recalculate the action time of each sector basic voltage vector, then according to the action sequence of the basic voltage vector and the action time of the basic voltage vector, determine the action time of the IGBT power switch tube switching state, generate 6-way PWM signals to control the on-off of the IGBT power switch tube, complete the control of the variable boost ratio type three-phase motor driver, the specific method is: Determine the inductance discharge time and inductance charging time: The seven kinds of switching states corresponding to the basic voltage vectors V0(000), V1(100), V2(110), V3(010), V4(011), V5(001), V6(101) are inductance charging states, and the corresponding conduction time is inductance charging time. The switching state corresponding to the basic voltage vector V7(111) is inductance discharge state, and the corresponding conduction time is discharge time; Define the duty cycle D: where T u is the inductive discharge time, T w is the inductive charging time, T s is the sampling period time; Define the boost gain X: During inductive charging, the capacitor discharges to power the back-end load, and during inductive discharge, the capacitor charges to store energy. In a sampling period, the voltage across the two capacitors C f is determined according to the inductor volt-second balance principle cf is: From the above formula, when the time ratio under the charging and discharging switching state is changed, the boost ratio can be changed, and the boost gain X is defined as: Based on the boost control strategy, the action time of the zero vector is redistributed: The time of the basic voltage vector V7 (111) that changes the inductive discharge state can change the boost ratio, and the action time of the V7 (111) state is T n The action time of the V7 (111) is: Thus, the adjusted action time of each sector basic voltage vector is obtained, the action time of basic voltage vector VI (100) in sector I is Tl, the action time of V2 (110) is T2, the action time of V0 (000) is TO-T n , and the action time of V7 (111) is T n ; the action time of basic voltage vector V2 (110) in sector II is Tl, the action time of V3 (010) is T2, the action time of V0 (000) is TO-T n , and the action time of V7 (111) is T n ; the action time of basic voltage vector V3 (010) in sector III is Tl, the action time of V4 (011) is T2, the action time of V0 (000) is TO-T n , and the action time of V7 (111) is T n ; the action time of basic voltage vector V4 (011) in sector IV is Tl, the action time of V5 (001) is T2, the action time of V0 (000) is TO-T n , and the action time of V7 (111) is T n ; the action time of basic voltage vector V5 (001) in sector V is Tl, the action time of V6 (101) is T2, the action time of V0 (000) is TO-T n , and the action time of V7 (111) is T n ; the action time of basic voltage vector V6 (101) in sector VI is Tl, the action time of VI (100) is T2, the action time of V0 (000) is TO-T n , and the action time of V7 (111) is T n .

7. The control method of a multi-operating state three-phase motor drive according to claim 6, characterized by, (3) In fault-tolerant SVPWM control, the basic voltage vector when a single tube or single-phase fault is reconstructed, and a virtual vector is synthesized, the specific method is: Reconstruct the basic voltage vector when a single tube or single-phase fault: After single-tube or single-phase fault occurs, the winding of the fault phase motor is connected to the midpoint of the capacitor through the opened bidirectional thyristor, only the four power switch tubes IGBT of the upper and lower bridge arms of the remaining two non-fault phases work normally, the boost three-phase motor driver is controlled and operated by the four IGBT power switch tubes, there are four voltage state combinations, i.e. four switching states, respectively corresponding to four basic voltage vectors, which are V1(00), V2(10), V3(11) and V4(01), and the four basic voltage vectors are all effective vectors; after a fault occurs in one of the A, B and C phases, the four basic voltage vectors V1(00), V2(10), V3(11) and V4(01) are sequentially arranged in the plane according to the clockwise direction, each adjacent vector is separated by 90°, there are four sectors in the plane, in order to simplify the calculation of the reference vector after each phase fault, the positive directions of the coordinate axes α and β are the positive directions of the basic voltage vectors V1(00) and V2(10), the reference vector V ref The projection on the α, β axis is U α , U β ; Synthesize the virtual vector, including virtual effective vector and virtual zero vector: The virtual effective vector V is synthesized by using the basic voltage vectors V1 (00), V2 (10) 12 The virtual effective vector V is synthesized by using the basic voltage vectors V2 (10), V3 (11) 23 The virtual effective vector V is synthesized by using the basic voltage vectors V3 (11), V4 (01) 34 The virtual effective vector V is synthesized by using the basic voltage vectors V4 (01), V1 (00) 41 The synthesis principle is: The four basic voltage vectors are all effective vectors, and the virtual vector V 12 , V 23 , V 34 , V 41 is an effective vector; the virtual zero vector needs to select two of the four basic voltage vectors to synthesize, and the synthesis principle is:

8. The control method of a multi-operating state three-phase motor driver according to claim 7, characterized by, (3) In the fault-tolerant SVPWM control, the action vectors are selected to re-divide the 6 sectors, and the action order and action time of the action vectors of each sector are determined. The specific method is as follows: Re-divide the 6 sectors: V1(00), V3(11) in four basic space vectors and the synthesized four virtual effective vectors V 12 , 23 , 34 , 41 and the virtual zero vector V 00 as the effective vectors of the synthesized reference vectors, V1(00), V3(11), V 12 , 23 , 34 , 41 The amplitudes of the six effective vectors are equal, mutually symmetrical and mutually different by 60° in space. Taking the α axis as the reference, the six sectors I, II, III, IV, V and VI are obtained by counterclockwise rotation by 60° in turn. According to the seven-segment vector synthesis principle, determine the action order of the action vectors of the synthesized reference vectors of each sector: First sector: V 00 V1V 12 V 00 V 12 V1V 00 ; Second sector: V 00 V 23 V 12 V 00 V 12 V 23 V 00 ; Third sector: V 00 V 23 V3V 00 V3V 23 V 00 ; Fourth sector: V 00 V 34 V3V 00 V3V 34 V 00 ; Fifth sector: V 00 V 34 V 41 V 00 V 41 V 34 V 00 ; Sixth sector: V 00 V1V 41 V 00 V 41 V1V 00 ; Determine the action time of the action vectors of each sector: Definition of T x , T y , T z are the effective time of two adjacent effective vectors and virtual zero vectors, respectively, in one cycle: The acting vector of the first sector is V1, V 12 , V 00 , and the acting time is T x , T y , T z , respectively. The acting vector of the second sector is V 12 , V 23 , V 00 , and the acting time is T x , T y , T z , respectively. The acting vector of the third sector is V 23 , V3, V 00 , and the acting time is T x , T y , T z , respectively. The acting vector of the fourth sector is V3, V 34 , V 00 , and the acting time is T x , T y , T z , respectively. The acting vector of the fifth sector is V 34 , V 41 , V 00 , and the acting time is T x , T y , T z , respectively. The acting vector of the sixth sector is V 41 , V1, V 00 , and the acting time is T x , T y , T z , respectively.

9. The control method of a multi-operating state three-phase motor drive according to claim 8, characterized by, (3) In the fault-tolerant SVPWM control, the action time of the virtual vector is allocated to the four basic voltage vectors, and the action order and action time of the basic voltage vectors of the synthesized reference vectors of each sector are determined. The specific method is as follows: Allocate the action time of the virtual vector to the four basic voltage vectors, and determine the action time of the basic voltage vectors of the synthesized reference vectors of each sector: According to the synthesis principle of virtual effective vector and virtual zero vector, the action time of the virtual vector is re-allocated to the four basic voltage vectors, and the time of V1(00), V2(10), V3(11), and V4(01) four basic voltage vectors is defined as T1, T2, T3, and T4 respectively: The basic voltage vectors used by the first sector are V1(00), V2(10), and V3(11), and their corresponding action times are The basic voltage vectors used by the second sector are V1(00), V2(10), and V3(11), and their corresponding action times are The basic voltage vectors used by the third sector are V1(00), V2(10), and V3(11), and their corresponding action times are The basic voltage vectors used by the fourth sector are V1(00), V4(01), and V3(11), and their corresponding action times are The basic voltage vectors used by the fifth sector are V1(00), V4(01), and V3(11), and their corresponding action times are The basic voltage vectors used by the sixth sector are V1(00), V4(01), and V3(11), and their corresponding action times are Determine the action time of the basic voltage vectors: Considering the minimum switching loss, according to the five-segment vector synthesis principle, the action order of the basic voltage vectors of the boost-type three-phase four-switch topology is determined as follows: First, second, and third sectors: V1(00), V2(10), V3(11), V2(10), V1(00) Fourth, fifth, and sixth sectors: V1(00), V4(01), V3(11), V4(01), V1(00), According to the action order of the basic voltage vectors and the action time of the basic voltage vectors, the action time of the IGBT power switch state is determined, 4 PWM signals are generated to control the on-off of the IGBT power switch, and the fault-tolerant control of the boost-type motor driver is completed.

10. The control method of a multi-operating state three-phase motor driver according to claim 4, characterized by, According to the action order and action time of the basic voltage vectors, the action time of the IGBT power switch state is determined, PWM signals are generated to control the on-off of the IGBT power switch, and the control of the normal three-phase motor driver is completed. The specific method is as follows: According to the action sequence of the basic voltage vector, the action time and the switching point of the IGBT power switch tube conduction time, the action time of the IGBT power switch tube switching state is determined, the DPWM technology is used, the action time of the IGBT power switch tube switching state is modulated with the triangular carrier whose frequency is the switching frequency of the IGBT power switch tube, at the same time, the on-off time of the IGBT power switch tube adds the dead time, the PWM signal is generated, and the on-off of the IGBT power switch tube is controlled to complete the control of the multi-working-state three-phase motor driver.

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