CN115149884A - A boosted three-phase electric driver and its fault-tolerant control method - Google Patents

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

A boosted three-phase electric driver and its fault-tolerant control method

technical field

The invention belongs to the technical field of electric drive control, and in particular relates to a boosted three-phase electric drive and a fault-tolerant control method thereof.

Background technique

Some energy storage or power generation devices, such as energy storage batteries, fuel cells, photovoltaic power generation devices, etc. are built using low voltage batteries. To get a higher voltage, one way is to connect in series to get the desired voltage. Due to the differences between cells and different operating conditions, the series connection of a large number of cells will increase the complexity of the system and may degrade its performance. Another way is to use a DC-DC boost converter between the DC source and the driver, and then invert to AC for practical applications. Such systems requiring additional boost circuits are called two-stage drivers. Depending on the power and voltage levels involved, with a two-stage driver, problems such as system bulk, weight, cost, and reduced efficiency can arise.

A single-stage DC-AC drive with boost capability, which is superior to a two-stage drive in terms of size, cost, weight, and overall system complexity, is a good alternative. In the case of high load and overload operation, the power switch tube is the most vulnerable part of the converter. The survey shows that the failure rate of the switch tube in the converter system has reached 38%. In order to avoid major accidents and reduce downtime, and restore the performance before the failure as much as possible, it is necessary to carry out fault-tolerant control of the step-up three-phase electric drive system.

The existing single-stage three-phase inverters with buck-boost function mainly include Z-source inverter (ZSI), buck-boost voltage source inverter (BBVSI), Y-source inverter (YSI), Split Source Inverter (SSI). SSI has additional advantages over these topologies. Compared to BBVSI, which uses additional active semiconductor switches, SSI uses only diodes; compared to ZSI and YSI, it reduces the number of passive components. The voltage on the bridge of the SSI is constant and can be controlled using the same modulation scheme as a conventional three-phase voltage source inverter (VSI). The paper "Three-Phase Split-Source Inverter (SSI): Analysis and Modulation" analyzes the working mode and modulation method of the split-source inverter SSI. However, there is no research on the fault-tolerant technology for the three-phase six-switch split-source inverter.

SUMMARY OF THE INVENTION

The purpose of the present invention is to propose a boosted three-phase electric driver and a fault-tolerant control method thereof.

The technical solution to achieve the purpose of the present invention is: a boost type three-phase electric driver, the DC side is composed of two series capacitors C _f , and the midpoint of the two capacitors is connected to a through three triacs TR1, TR2, TR3 respectively. , b, c three-phase winding ends, the other end of the series capacitor is connected to the a-phase, b-phase, and c-phase of the three-phase bridge arm respectively; the negative pole of the power supply U _In is connected to the lower bridge of the three-phase bridge arm a-phase, b-phase, and c-phase arm, the positive pole is 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 connected to the three-phase winding ends of a, b, and c respectively; Phase c consists of six IGBT power switches S1~S6 and six diodes D1~D6 connected in parallel with the switches. Each phase bridge arm is connected in series with 2 fast fuses, and there are 6 fast fuses F1~F6 in total; When a short-circuit fault occurs in the power device of one bridge arm, the corresponding fast fuse is blown, and the faulty bridge arm is disconnected; when an open-circuit fault occurs, the faulty bridge arm automatically fails, and stops inputting the drive signal of the switch of the faulty bridge arm, and simultaneously turns on the corresponding bidirectional thyristor to switch The system is a boosted three-phase four-switch topology.

q轴电流，分别与d、q轴电流参考值作差输入PI调节器，输出d、q轴电压参考值，经过Park逆变换得到α、β轴电压参考值

，输入SVPWM控制模块生成6路控制IGBT门极通断的信号；Further, the speed outer loop and the current inner loop are used for double closed-loop operation, in which the speed loop collects the motor speed, and the difference with the reference speed is input to the PI regulator to output the q-axis current reference value; the current loop collects the three-phase current and the motor electrical angle, After Park transformation, d is obtained

The q-axis current is respectively different from the reference values of the d and q-axis currents, and is input to the PI regulator to output the reference values of the d and q-axis voltages. After Park inverse transformation, the reference values of the α and β-axis voltages are obtained.

, input the SVPWM control module to generate 6-channel signals to control the on-off of the IGBT gate;

In fault-tolerant operation, the outer loop of voltage and speed is used, and the inner loop of current is three closed-loop operation. The speed loop and current loop are the same as those in normal operation. The voltage reference value in the voltage loop is twice that of the DC side capacitor voltage in normal operation, which is the same as the collected data. The voltage difference of the DC side capacitor is input to the PI regulator, and the intermediate variable Tz is output, which is input to the SVPWM module. The PI module continuously adjusts the value of Tz until the DC side capacitor voltage Udc rises to twice the original value, completing the fault-tolerant control.

A fault-tolerant control method for a boosted three-phase electric driver, which completes the fault-tolerant control based on the boosted three-phase electric driver, comprising the following steps:

Step 1. Establish the basic voltage vector under no fault condition;

Step 2. According to the position of the fault switch tube, switch the topology of the boosted three-phase electric driver;

Step 3. Reconstruct the basic voltage vector in the case of a single-tube or single-phase fault;

Step 4. Use a 4-sector division method to divide the sectors;

Step 5. Select the action vector from the reconstructed basic voltage vector, and determine the corresponding action time;

Step 6. Determine the on-time of each switch tube after the boost-type three-phase electric driver reconstructs the topology;

Step 7, modulate the on-time of the switch tube with the triangular carrier wave, output the PWM pulse signal of the switch tube, and complete the fault-tolerant control.

Further, step 1, establish the basic voltage vector under no fault condition, as shown in Table 1:

Table 1 Fault-free basic voltage vector table

(Sa Sb Sc) is the switching function of the bridge arms of the a, b and c phases. The function value is "1", which means that the upper bridge arm switch of this phase is turned on, and "0" means that the lower bridge wall switch of this phase is turned on. The different switch state combinations of the switch tubes correspond to 8 basic voltage vectors respectively: U0 (000), U1 (100), U2 (110), U3 (010), U4 (011), U5 (001), U6 (101) ), U7(111), Ua, Ub, Uc in the table are the three-phase phase voltage of the three-phase driver, Uk is the basic voltage vector obtained after the three-phase voltage of a, b, c after Clark transformation, k is 0~7, Udc is the DC side capacitor voltage.

Further, in step 2, according to the position of the fault switch tube, switch the topology structure of the boosted three-phase electric driver, and the specific method is as follows:

When a phase fails, the boosted three-phase electric driver is controlled by the four switches of the b and c phases. When the b phase fails, the boosted three-phase electric driver is controlled by the four switches of the c and a phases, and the c phase When there is a fault, the step-up three-phase electric driver is controlled by the four switches of the a and b phases. Since the fault includes 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 Triac actions corresponding to open-circuit faults of different switches

When a short-circuit fault occurs in the switch tube, the fast fuse corresponding to the switch tube is blown, and the short-circuit fault is converted into an open-circuit fault. The actions of the bidirectional thyristor and the fast fuse corresponding to the short-circuit fault are shown in Table 3;

Table 3 Triac and fast fuse actions corresponding to short-circuit faults of different switches

Further, in step 3, the basic voltage vector in the case of a single-tube or single-phase fault is reconstructed, and the specific method is as follows:

Determine the relationship between the motor phase voltage and the switching state:

In the formula, Ua, Ub, Uc are the three-phase phase voltages of the three-phase driver, Sa, Sb, and Sc represent the switching states of the power devices on the bridge arms of a, b, and c, respectively. When equal to "1", it means that the upper tube is turned on and the lower tube is turned off , when it is equal to "0", it means that the lower tube is turned on and the upper tube is turned off; when the a phase fails, the motor winding a phase is connected to the midpoint of the capacitor, and Sa is always 1/2; the step-up three-phase electric drive is driven by b and c phases. The four switches are controlled by (Sb Sc)=(0 0), (Sb Sc)=(0 1), (Sb Sc)=(1 0), (Sb Sc)=(1 1) 4 switches state; when the b-phase fails, the motor winding b-phase is connected to the midpoint of the capacitor, Sb is always 1/2, the boost three-phase electric driver is controlled by the four switch tubes of c and a phases, with (Sc Sa)= (0 0), (Sc Sa)=(0 1), (Sc Sa)=(1 0), (Sc Sa)=(11) 4 switch states; when the c-phase fails, the motor winding c-phase is connected to The midpoint of the capacitor, Sc is always 1/2, the boost three-phase electric driver is controlled by the four switches of the a and b phases, with (Sa Sb)=(0 0), (Sa Sb)=(0 1) , (Sa Sb)=(1 0), (SaSb)=(1 1) 4 switch states;

Determine the three-phase composite voltage space vector:

为空间旋转因子；in the formula

is the spatial rotation factor;

Determine the basic voltage vector for reconstructed single-tube or single-phase fault conditions, as shown in Table 4;

Table 4 Reconstructed basic voltage vector table

’、

’正方向为基本电压矢量U0’、U2’的正方向，参考矢量

在

’、

’轴上的投影为

、

。Due to the failure of one of the three phases a, b and c, the four basic voltage vectors U0', U1', U2', U3' are clockwise in the plane according to U0', U1', U3', U2' Sorting, each adjacent vector is separated by 90°, in order to simplify the calculation of the reference vector after unifying the faults of each phase, let the coordinate axis

',

'The positive direction is the positive direction of the basic voltage vector U0', U2', the reference vector

exist

',

' The projection on the axis is

,

.

Further, in step 4, a four-sector division method is used to divide the sectors, and the specific method is as follows:

Define the function:

；

;

Define the sector calculation value N:

Determine the correspondence between N and the actual sector number through Table 5, and complete the sector division;

Table 5 The calculated value of N and the corresponding relationship table of sectors

Further, in step 5, the action vector is selected from the reconstructed basic voltage vector, and the corresponding action time is determined, and the specific method is as follows:

Step 5.1, select the action vector from the reconstructed basic voltage vector;

The action vector includes an effective vector and a zero vector. The basic voltage vectors U0'~U3' are used as effective vectors alone, and two basic voltage vectors in opposite directions are used to synthesize an equivalent zero vector, that is, U0' (00), U3' (11 ) to synthesize an equivalent zero vector, and use U1'(01) and U2'(10) to synthesize another equivalent zero vector; combine the effective vector and the equivalent zero vector to synthesize the reference vector;

Considering the minimum switching loss, when the reference vector is located in the first sector, the basic voltage vector action sequence is selected as U2', U0', U1', U3'; when the reference vector is in the second sector, the basic voltage vector action sequence is selected. The sequence is U3', U2', U0', U1'; when the reference vector is in the third sector, the basic voltage vector action sequence is U1', U3', U2', U0'; when the reference vector is in the fourth sector In the area, select the basic voltage vector action sequence as U0', U1', U3', U2';

Step 5.2, determine the action time of the action vector;

Define intermediate variables:

where Ts is the switching period;

Suppose the effective vectors of the first sector are U0', U2', and the action times are Tx and Ty respectively; the effective vectors of the second sector are U2', U3', and the action times are Tx and Ty respectively; the third sector The effective vectors of the zone action are U3', U1', and the action time is Tx, Ty respectively; the effective vector of the fourth sector action is U1', U0', the action time is Tx, Ty respectively; Determine each sector through Table 6 The action time of the effective vector;

Table 6 Action time of effective vector of each sector

Define the action time of the equivalent zero vector:

T0=Ts-Tx-Ty

Since the equivalent zero vector of each sector is synthesized by U0', U1', U2', U3', the intermediate variables are defined:

0<=Tz<=T0

、

；U0’、U3’的作用时间为

、

；The action time of the two basic voltage vectors of the synthetic equivalent zero vector is equal, then the action time of U1', U2' is

,

; The action time of U0', U3' is

,

;

Determine the basic voltage vector action time of each sector according to Table 7:

Table 7 Basic voltage vector action time of each sector

。

.

Further, in step 6, the on-time of each switch tube after the topology reconstruction of the boosted three-phase electric driver is determined, and the specific method is as follows:

Table 8 Switching time points of each switch after topology reconstruction

In one switching cycle, the switching time point of each switch tube after the topology is reconstructed is determined by Table 8. In the table, the values of M and N are a, b, and c. When M=a, b, and c, the corresponding of N = b, c, a;

The turn-on time points and turn-off time points of the M and N phases represent the turn-on and turn-off times of the upper switch tubes of the M and N phases, the turn-on and turn-off states of the lower switch tubes of the phase and the upper switch tubes of the phase Tubes are complementary.

Further, in step 7, the conduction time of the switch tube is modulated with the triangular carrier wave, and the PWM pulse signal of the switch tube is output to complete the fault-tolerant control. The specific method is:

The DPWM technology is used to modulate the triangular carrier whose on and off time and period are the switching period of the switch, and the dead time is added according to the on and off time of the power switch to obtain the PWM pulse;

The 4-way PWM pulse is applied to the power switch tube drive circuit, and the drive circuit controls the corresponding power switch tube to be turned on and off;

Collect the DC voltage of the capacitor side, make a difference with the reference voltage and input it to the PI controller, output the intermediate variable Tz, and use Tz as the input of the time module of each sector vector action time, which plays the function of adjusting the DC side capacitor voltage until the DC side capacitor voltage reaches The reference value is used to complete the fault-tolerant control of the electric drive system.

A fault-tolerant control system for a boosted three-phase electric drive is used to realize the fault-tolerant control method for a boosted three-phase electric drive.

A computer device, comprising a memory, a processor and a computer program stored in the memory and running on the processor, when the processor executes the computer program, the fault-tolerant control of the boosted three-phase electric drive is realized method.

A computer-readable storage medium stores a computer program thereon, and when the computer program is executed by a processor, realizes the fault-tolerant control method for a boosted three-phase electric drive.

Compared with the prior art, the present invention has the following significant advantages: 1) Combined with the SSI inverter topology and the three-phase four-switch driver fault-tolerant topology, the control algorithm of the system is switched after the fault, and a voltage loop is introduced, and the system consists of the original speed loop, The double-loop control of the current loop is switched to the three-loop control of the voltage loop, the speed loop and the current loop, so that the voltage of the DC side capacitor is raised to twice the original, and the fault-tolerant control operation with high power quality and full load is realized. 2) After the fault occurs, the capacitor voltage is increased to twice the original value, and the voltage vector circle is restored to the size of the normal control. It solves the problem that the rated speed/power is reduced by half due to the voltage vector circle dropping to half of the original during the traditional three-phase four-switch fault-tolerant operation. 3) Using fewer active devices, only three additional triacs need to be added to the three-phase boost driver. After obtaining the fault switch tube information, the single-stage boost can be realized by changing the topology and control algorithm. The drive's fault tolerance reduces system size, cost, weight, and complexity. 4) 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.

Description of drawings

Figure 1 is a topology diagram of a step-up three-phase electric driver with fault tolerance.

Fig. 2 is the fault-tolerant control block diagram of the step-up three-phase electric driver.

Figure 3(a) is a schematic diagram of a three-phase six-switch inverter space vector circle; Figure 3(b) is a schematic diagram of a reduced vector circle after the three-phase six-switch is switched to a conventional three-phase four-switch fault-tolerant topology; Figure 3(c) It is a schematic diagram of the voltage vector circle that restores the normal size by the fault-tolerant control method.

Figure 4(a) is a schematic diagram of the current flow of the a-phase switch tube failure when the a-phase current is greater than zero and less than zero; Figure 4(b) is the a-phase switch tube fault when the b-phase current is greater than zero, the b-phase bridge arms are different The schematic diagram of the current flow in the switching state; Figure 4(c) is a schematic diagram of the current flow of the b-phase bridge arm in different switching states when the a-phase switch tube fails when the b-phase current is less than zero; Figure 4(d) is the a-phase switch tube When the fault c-phase current is greater than zero, the current flow of the c-phase bridge arm in different switching states; Figure 4(e) shows the c-phase bridge arm in different switching states when the a-phase switch tube fault c-phase current is less than zero. Schematic diagram of current flow.

Figure 5(a) is the equivalent circuit diagram of the system when the switch of phase a is faulty and the switch state is (Sb Sc)=(00), (01), (10); Figure 5(b) is the fault of the switch of phase a , when the switch state is (Sb Sc) = (11), the equivalent circuit diagram of the system.

Figure 6(a) is a schematic diagram of the three-phase current of the motor in normal operation; Figure 6(b) is a schematic diagram of the voltage source input voltage UIn and the DC side capacitor voltage Udc in normal operation; Figure 6(c) is a schematic diagram of the motor speed in normal operation; Figure 6(d) is a schematic diagram of the electromagnetic torque of the motor during normal operation.

Figure 7(a) is a schematic diagram of the three-phase current of the motor when the switch tube of phase a is faulty; Figure 7(b) is a schematic diagram of the input voltage UIn of the voltage source and the capacitor voltage Udc of the DC side when the switch tube of phase a is faulty; Figure 7(c) Figure 7(d) is a schematic diagram of the motor's electromagnetic torque when the a-phase switch tube fails. It can be seen from the figure that the motor is out of control after the fault and is dragged backward by the load. Turn run.

Figure 8(a) is a schematic diagram of the three-phase current of the motor during the fault-tolerant operation of the a-phase switch tube; Figure 8(b) is a schematic diagram of the voltage source input voltage UIn and the DC side capacitor voltage Udc during the fault-tolerant operation of the a-phase switch tube; Figure 8( c) is the schematic diagram of the motor speed during the fault-tolerant operation of the a-phase switch tube; Fig. 8(d) is the schematic diagram of the electromagnetic torque of the motor during the fault-tolerant operation of the a-phase switch tube.

Detailed ways

The solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

In order to make the purpose, technical solutions and advantages of the present application more clearly understood, the present application will be described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, but not to limit the present application.

Figure 1 is a step-up three-phase electric drive topology with fault tolerance. TR1, TR2, TR3 are triacs; L1 is inductance; D7, D8, D9 are diodes; C _f is DC side capacitance; S1~S6 are power switch IGBTs; D1~D6 are diodes; F1~F6 are fast fuses ; U _In is the external input DC power supply; Udc is the DC side capacitor voltage. When the system is running normally, the triacs TR1, TR2, and TR3 are kept off. The system uses conventional three-phase six-switch SVPWM for control without changing the control algorithm. This topology has the function of increasing the voltage level of the DC power supply U _In . When a short-circuit or open-circuit fault occurs in a bridge arm power device of the driver, the faulty bridge arm is disconnected, and the corresponding bidirectional thyristor is turned on at the same time, and the switching system is a three-phase four-switch topology. i _a , ib , and ic are the currents flowing through the phases a, _b , and _c of the motor.

q轴电流，分别与d，q轴电流参考值作差输入PI调节器，输出d，q轴电压参考值，经过Park逆变换得到α、β轴电压参考值

；输入SVPWM控制模块生成6路控制IGBT门极通断的信号。6路门极信号输入到三相六开关拓扑中。三相六开关拓扑引出a，b，c三相与电机a、b、c三相相连。容错运行时，采用电压、转速外环，电流内环三闭环运行。转速环，电流环与正常运行时一致，电压环中电压参考值是正常运行时直流侧电容电压的两倍，与采集到的直流侧电容电压作差，输入PI调节器，输出Tz，Tz输入到修改后的SVPWM模块中，生成4路控制IGBT门极通断的信号。4路门极信号输入到三相四开关拓扑中。三相四开关拓扑引出a、b、c三相与电机a、b、c三相相连。PI模块不断调整Tz的值直至直流侧电容电压Udc抬升到原先的两倍，完成容错控制。Figure 2 is a control block diagram of a step-up three-phase electric driver. The permanent magnet synchronous motor PMSM comes with an encoder. The encoder collects the electrical angle θ _e when the motor is running. θ _e obtains the motor speed w through differential transformation. The rotational speed reference value w ^* , the d-axis current reference value I _d ^* , and the DC-side capacitor voltage reference value Udc ^* are set manually. During normal operation, the boost-type three-phase electric driver adopts the double closed-loop design of the outer speed loop and the inner loop of the current. The reference speed is set manually. The outer loop of the speed is: collect the motor speed, input the difference with the reference speed to the PI regulator, and output the q-axis current reference value. The inner loop of the current is: collecting the three-phase current and the electrical angle of the motor, and obtaining d after Park transformation

The q-axis current is respectively different from the d and q-axis current reference values and input to the PI regulator to output the d and q-axis voltage reference values. After Park inverse transformation, the α and β-axis voltage reference values are obtained.

; Input the SVPWM control module to generate 6 signals to control the on-off of the IGBT gate. The 6-way gate signals are input into the three-phase six-switch topology. The three-phase six-switch topology leads out a, b, c three-phase and connects with motor a, b, c three-phase. In fault-tolerant operation, the outer loop of voltage and speed is adopted, and the inner loop of current is three closed-loop operation. The speed loop and current loop are the same as those in normal operation. The voltage reference value in the voltage loop is twice the DC side capacitor voltage in normal operation, and the difference with the collected DC side capacitor voltage. Input PI regulator, output Tz, Tz input In the modified SVPWM module, 4 channels of signals are generated to control the on-off of the IGBT gate. Four gate signals are input into the three-phase four-switch topology. The three-phase four-switch topology leads out a, b, c three-phase and connects with motor a, b, c three-phase. The PI module continuously adjusts the value of Tz until the DC side capacitor voltage Udc rises to twice the original value to complete fault-tolerant control.

A fault-tolerant control method for a boosted three-phase electric driver, comprising the following steps:

Step 1. Establish the basic voltage vector without fault, as shown in Table 1;

Table 1 Basic voltage vector table under no fault condition

(Sa Sb Sc) is the switching function of the bridge arms of the a, b and c phases. The function value is "1", which means that the upper bridge arm switch of this phase is turned on, and "0" means that the lower bridge wall switch of this phase is turned on. The different switch state combinations of the switch tubes correspond to 8 basic voltage vectors, respectively: U 0 (000), U 1 (100), U 2 (110), U 3 (010), U 4 (011), U 5 ( 001), U 6 (101), U 7 (111). In the table, Ua, Ub, and Uc are the three-phase voltages of the three-phase driver, and Uk is the basic voltage vector obtained after the three-phase voltages of a, b, and c are transformed by Clark, and k takes 0~7. Udc is the DC side capacitor voltage.

Step 2. According to the position of the fault switch tube, switch the topology of the boosted three-phase electric driver;

Under normal conditions, the system is a boosted three-phase six-switch topology. The midpoints of the two series capacitors between the busbars are connected to the winding terminals through three triacs, and two fast fuses are connected in series in each bridge arm. When the a phase fails, the boosted three-phase electric driver is controlled by the four switching tubes of the b and c phases, and the bidirectional thyristor TR1 is turned on. When the b phase fails, the boosted three-phase electric driver is controlled by the four switch tubes of the a and c phases, and the bidirectional thyristor TR2 is turned on. When the c-phase fails, the boosted three-phase electric driver is controlled by the four switching tubes of the a and b phases, and the bidirectional thyristor TR3 is turned on.

The faults are divided into open-circuit faults and short-circuit faults. The bidirectional thyristor actions corresponding to the open-circuit faults are shown in Table 2:

Table 2 Triac actions corresponding to open-circuit faults of different switches

When a short-circuit fault occurs in the switch tube, the fast fuse corresponding to the switch tube is blown, and the short-circuit fault is converted into an open-circuit fault. The bidirectional thyristor and fast fuse actions corresponding to the short-circuit fault are shown in Table 3:

Table 3 Triac and fast fuse actions corresponding to short-circuit faults of different switches

Udc/3，Udc为电容侧电压，图3（b）为a相故障之后，三相六开关切换为三相四开关容错拓扑之后，重构的矢量圆，短矢量的长度为Udc /3，长矢量的长度为

Udc/3，矢量圆的半径降低为原先的一半，为

Udc/6。常规的三相六开关驱动器切换为四开关驱动器时，由于空间矢量圆降为原来的一半，导致额定输出功率也会降低为原先的一半。要想保持额定的输出转矩，则额定转速需要下降为原来的一半。具备容错能力的升压型三相六开关SSI驱动器恰好可以解决这个问题。在升压型三相六开关SSI拓扑切换为升压型三相四开关SSI拓扑时，也会出现矢量圆缩小的情况，缩小的大小与系统的零矢量作用时间有关。升压型三相四开关SSI驱动器的作用是进一步提升直流电压，将直流侧电容电压提升为原先三相六开关SSI拓扑的两倍，则缩小的每个矢量扩大为原先的两倍，矢量圆也会恢复为原先的大小。如图3（c），当电压矢量圆的半径恢复为原先

Udc/3时，即可实现系统的全功率容错运行。Take a phase failure as an example. Figure 3(a) is a three-phase six-switch inverter space vector circle, the length of each vector is 2Udc/3, and the radius of the vector circle is

Udc/3, Udc is the capacitor side voltage. Figure 3(b) shows the reconstructed vector circle after the phase a fault and the three-phase six-switch is switched to the three-phase four-switch fault-tolerant topology. The length of the short vector is Udc/3, The length of the long vector is

Udc/3, the radius of the vector circle is reduced to half of the original, which is

Udc/6. When the conventional three-phase six-switch driver is switched to a four-switch driver, since the space vector circle is reduced to half of the original, the rated output power will also be reduced to half of the original. To maintain the rated output torque, the rated speed needs to be reduced by half. The fault tolerant step-up three-phase six-switch SSI driver can solve this problem. When the boosted three-phase six-switch SSI topology is switched to the boosted three-phase four-switch SSI topology, the vector circle will also shrink, and the size of the shrinkage is related to the zero-vector action time of the system. The function of the step-up three-phase four-switch SSI driver is to further increase the DC voltage, and the DC side capacitor voltage is increased to twice the original three-phase six-switch SSI topology, and each reduced vector is expanded to twice the original, the vector circle will return to its original size. As shown in Figure 3(c), when the radius of the voltage vector circle is restored to the original

When Udc/3, the full power fault-tolerant operation of the system can be realized.

Step 3. Reconstruct the basic voltage vector in the case of a single-tube or single-phase fault;

Determine the relationship between the motor phase voltage and the switch state as:

Define the three-phase composite voltage space vector:

为空间旋转因子。in the formula

is the spatial rotation factor.

Let Sa, Sb, and Sc represent the switching states of the power devices on the bridge arms of a, b, and c respectively. When it is equal to "1", it means that the upper tube is turned on and the lower tube is turned off, and when it is equal to "0", it means that the lower tube is turned on and the upper tube is turned off. When phase a fails, phase a of the motor winding is connected to the midpoint of the capacitor, and Sa is always 1/2. The step-up three-phase electric driver is controlled by the four switches of the b and c phases, with (Sb Sc)=(00), (Sb Sc)=(0 1), (Sb Sc)=(1 0), ( Sb Sc)=(1 1) 4 switch states. When phase b fails, phase a of the motor winding is connected to the midpoint of the capacitor, and Sb is always 1/2. The step-up three-phase electric driver is controlled by four switches of c and a phases, with (ScSa)=(0 0), (Sc Sa)=(0 1), (Sc Sa)=(1 0), ( Sc Sa)=(1 1) 4 switch states. When the c-phase fails, the c-phase of the motor winding is connected to the midpoint of the capacitor, and Sc is always 1/2. The step-up three-phase electric driver is controlled by four switches of the a and b phases, with (Sa Sb)=(0 0), (Sa Sb)=(0 1), (Sa Sb)=(1 0), (Sa Sb)=(1 1) 4 switch states. U0', U1', U2', and U3' correspond to the basic voltage vectors of the two-phase switches (00), (01), (10), and (11) in the switching states of the two-phase switches that work after the above fault, respectively.

The basic voltage vectors for reconstructed single-tube or single-phase fault conditions are shown in Table 4

Table 4 Reconstructed basic voltage vector table

’、

’ 正方向为基本电压矢量U0’、 U2’的正方向。参考矢量

在

’、

’轴上的投影为

、

。Due to the failure of one of the three phases a, b and c, the four basic voltage vectors U0', U1', U2', U3' are in the order of U0', U1', U3', U2' in the plane. Clockwise, each adjacent vector is 90° apart. In order to simplify the calculation of the reference vector after the failure of each phase a, b, and c, let the coordinate axis

',

' The positive direction is the positive direction of the basic voltage vectors U0', U2'. reference vector

exist

',

' The projection on the axis is

,

.

Take a-phase switch tube failure as an example. It is stipulated that the direction flowing into the motor is the positive direction of the current. When the a-phase switch tube fails, the a-phase is connected to the midpoint of the DC side capacitor through a triac. Figures 4(a) to 4(e) show the current flows of the three-phase a, b, and c currents in each switching vector state. Figure 4(a) is the current flow of phase a current when it is greater than zero and less than zero; Figure 4(b) is the current flow of phase b when the current is greater than zero and the current flow of the bridge arm of phase b in different switching states; Figure 4(c) ) is the current flow of the b-phase bridge arm in different switching states when the b-phase current is less than zero; Fig. 4(d) is the current flow of the c-phase bridge arm in different switching states when the c-phase current is greater than zero; Fig. 4 (e) is the current flow of the c-phase bridge arm in different switching states when the c-phase current is less than zero. Figures 5(a) to 5(b) are used to illustrate the equivalent circuit diagram of the three-phase four-switch fault-tolerant SSI charging and discharging. S6, ₂ means that one of the switch tubes S6 and S2 is turned on, and both of the switch tubes S6 and S2 are turned on. S 3 and ₅ indicate that both switches S3 and S5 are turned on. Figure 5(a) is the equivalent circuit diagram of the system when the switch states are (Sb Sc)=(00), (01), (10). At this time, the system discharges the capacitor C _f and charges the inductor L1. Figure 5(b) is the equivalent circuit diagram of the system when the switch state is (Sb Sc) = (11). At this time, the system charges the capacitor C _f and the inductor L1 discharges. Therefore, in the four switching states, only (Sb Sc) = (11) is the charge of the capacitor C _f and the discharge of the inductor L1. By allocating different vector action times, that is, by allocating the charging and discharging times of the capacitor C _f and the inductor L1 , the purpose of controlling the DC voltage U _In on the capacitor side can be achieved.

Step 4. Use the four-sector division method to divide the sectors, specifically:

Define the function:

；

;

Define the sector calculation value N function:

The corresponding relationship between the calculated value of N and the actual sector number is determined by Table 5, and the sector division can be completed;

Table 5 The corresponding relationship between the calculated value of N and the sector

Step 5. Select an action vector from the reconstructed basic voltage vector;

The basic voltage vectors U0'~U3' can be used alone as effective vectors, or two vectors in opposite directions can be used as equivalent zero vectors. Because there is no zero vector in the four-switch system, the equivalent zero vector needs to be equivalent by applying two basic voltage vectors in opposite directions at the same time. Use U0' (00), U3' (11) as a pair of equivalent zero vectors; use U1' (01), U2' (10) as another pair of equivalent zero vectors. The effective vector and the equivalent zero vector together form the reference vector.

Considering the minimum switching loss, when the reference vector is located in the first sector, the basic voltage vector action sequence is selected as U2', U0', U1', U3'; when the reference vector is in the second sector, the basic voltage vector action sequence is selected. The sequence is U3', U2', U0', U1'; when the reference vector is in the third sector, the basic voltage vector action sequence is U1', U3', U2', U0'; when the reference vector is in the fourth sector In the zone, select the basic voltage vector action sequence as U0', U1', U3', U2'.

In the boost-type three-phase four-switch SSI, there are four switch states (00), (01), (10), (11) corresponding to four basic voltage vectors, among which U0' (00), U1' (01 ), U2'(10), these three basic voltage vectors discharge the capacitor and charge the inductor, and only U3'(11) charge the capacitor and discharge the inductor. In each switching cycle, the reference vector is synthesized from the effective vector and the equivalent zero vector. The effective vector is fixed, and 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, and 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 allocated according to requirements. By controlling the relative time of the two pairs of equivalent zero vectors U0', U3' and U1', U2', the purpose of controlling the capacitor voltage can be achieved.

Step 5. Determine the action time of the basic voltage vector after the fault;

Define intermediate variables:

In the formula, Udc is the DC side capacitor voltage, Ts is the switching period;

Define the effective vector action time of each sector as Tx, Ty. The effective vectors of the first sector are U0', U2', and the action times are Tx and Ty respectively; the effective vectors of the second sector are U2', U3', and the action times are Tx and Ty respectively; the third sector The effective vectors of action are U3', U1', and the action times are Tx, Ty respectively; the effective vectors of the fourth sector are U1', U0', and the action times are Tx, Ty respectively. Table 6 determines the action time Tx and Ty of the effective vector in the basic voltage vector of each sector when the four sectors are divided:

Table 6 The action time T1 and T2 of the effective vector of each sector when the four sectors are divided

Define the equivalent zero vector action time:

T0=Ts-Tx-Ty

The equivalent zero vector of each sector is synthesized by U0', U1', U2', U3', U0', U3' is a pair; U1', U2' is a pair; two vectors in each pair The duration of action is equal.

Define intermediate variables:

0<=Tz<=T0

、

；另一对矢量U0’、 U3’的作用时间为

、

。在一个开关周期内，由基本电压矢量作为基础的有效矢量与等效零矢量共同作用，合成参考矢量。通过表7确定各扇区基本电压矢量作用时间：Let the action time of a pair of vectors U1', U2' be

,

; the action time of another pair of vectors U0', U3' is

,

. In one switching cycle, the effective vector based on the basic voltage vector and the equivalent zero vector work together to synthesize the reference vector. Determine the basic voltage vector action time of each sector according to Table 7:

Table 7 Action time of basic voltage vector in each sector

。

.

Step 6. Determine the on-time of each switch tube after the boost-type three-phase electric driver reconstructs the topology;

After the topology is reconstructed, the boosted three-phase electric driver is controlled by four IGBT power switch tubes, that is, a three-phase four-switch topology. From the action time of each sector vector in Table 7, in one switching cycle, determine the switching time point of each switch tube after the topology is reconstructed through Table 8;

Table 8 Switching time points of each switch after topology reconstruction

In the table, the values of M and N are a, b, and c. When M=a, b, c, the corresponding N= b, c, a. The turn-on time points and turn-off time points of the M and N phases represent the turn-on and turn-off times of the upper switches of the M and N phases. Tubes are complementary.

Step 7: Using DPWM technology, modulate the on-off time and off-time of the switch and a triangular carrier whose cycle is the switching period, and add the dead time to the modulated pulse according to the on-off time of the power switch to obtain a PWM pulse. The output 4 PWM pulses are applied to the drive circuit of the power switch tube, and the drive circuit controls the corresponding power switch tube to be turned on and off. Collect the DC voltage on the capacitor side, make a difference with the reference voltage and input it into the PI controller. The output variables Tz and Tz are used as the input of the modified SVPWM module to adjust the DC side capacitor voltage until the DC side capacitor voltage reaches the reference value, complete Full power fault tolerant control of electric drive systems.

By acquiring fault information and changing the corresponding system hardware topology and control algorithm, the present invention can realize state recovery under the condition of open-circuit fault or short-circuit fault of all single-pipe, double-pipe on the same bridge arm, and achieve fault-tolerant operation with high power quality and full load.

In order to verify the effectiveness of the solution of the present invention, the fault-tolerant control method is verified by taking the failure of the a-phase switch tube as an example.

Figure 6(a) is the three-phase current of the motor in normal operation; Figure 6(b) is the voltage source input voltage U _In and the DC side capacitor voltage Udc in normal operation. It can be seen from the figure that the input voltage U _In is 20V, After the circuit is boosted, the DC side capacitor voltage Udc is 115V; Figure 6(c) is the motor speed during normal operation, and the speed is 30rad/s; Figure 6(d) is the electromagnetic torque of the motor during normal operation, and the electromagnetic torque is About 11N*m.

Figure 7(a) shows the three-phase current of the motor during fault operation after the switch tube of phase a fails. It can be seen from the figure that the amplitude of the three-phase current increases sharply; Figure 7(b) shows the voltage source input voltage U _In and DC during fault operation. The side capacitor voltage Udc and the input voltage U _In are still 20V. It can be seen from the figure that the DC side capacitor voltage is slightly higher than the normal 115V. Figure 7(c) shows the motor speed during fault operation. It can be seen from the figure that the speed drops to a negative value, At this time, the motor is out of control and is dragged by the load and runs in reverse. Figure 7(d) shows the electromagnetic torque of the motor during fault operation. It can be seen from the figure that the electromagnetic torque of the motor oscillates sharply and is negative. At this point the entire system is in a state of collapse.

Figure 8(a) shows the three-phase current of the motor during fault-tolerant operation. It can be seen from the figure that the three-phase current basically returns to the state during normal operation; Figure 8(b) shows the voltage source input voltage U _In and the DC side during fault-tolerant operation. The capacitor voltage Udc, the input voltage U _In is still 20V, and the DC side capacitor voltage Udc is raised to twice the normal operation, 230V according to the demand, the purpose is to restore the system to full power operation; Figure 8(c) shows the fault-tolerant operation The motor speed, the motor speed returns to the state during normal operation, is 30rad/s; Figure 8(d) shows the electromagnetic torque of the motor during fault-tolerant operation, and the electromagnetic torque also returns to the state during normal operation, and the motor runs smoothly.

From the results of Figures 7(a)~7(d) and 8(a)~8(d), it can be seen that the fault-tolerant control method of the boost three-phase electric drive can be used in the system after the single-phase fault of the drive. After the fault, it has a good control effect on the current, speed, torque, and DC side capacitor voltage, and can still realize the fault-tolerant operation of the driver with high power quality and full load, which enhances the reliability of the system.

The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, all possible combinations of the technical features in the above embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, all It is considered to be the range described in this specification.

The above-mentioned embodiments only represent several embodiments of the present application, and the descriptions thereof are relatively specific and detailed, but should not be construed as limiting the scope of the present application. It should be pointed out that for those skilled in the art, without departing from the concept of the present application, several modifications and improvements can be made, which all belong to the protection scope of the present application. Therefore, the scope of protection of the present application should be determined by the appended claims.

Claims (10)

1. a boost type three-phase electric driver is characterized in that, the DC side is made up of two series capacitors C _f , and the midpoints of the two capacitors are respectively connected to a, b, c by 3 triacs TR1, TR2, TR3 The three-phase winding end, the other end of the series capacitor is connected to the a-phase, b-phase and c-phase of the three-phase bridge arm respectively; the negative pole of the power supply U _In is connected to the lower bridge arm of the three-phase bridge arm a-phase, b-phase and c-phase, and the positive pole is connected Inductor L1, the other end of inductance L1 is connected to the anodes of diodes D7, D8, D9, and the cathodes of diodes D7, D8, D9 are respectively connected to the three-phase winding ends of a, b, and c; IGBT power switch tubes S1~S6 and six diodes D1~D6 connected in parallel with the switch tubes, each phase bridge arm is connected in series with 2 fast fuses, there are 6 fast fuses F1~F6 in total; When the device has a short-circuit fault, the corresponding fast fuse is blown, and the faulty bridge arm is disconnected; when an open-circuit fault occurs, the faulty bridge arm automatically fails, and stops inputting the drive signal of the switch of the faulty bridge arm, and simultaneously turns on the corresponding bidirectional thyristor, and the switching system is boosted. type three-phase four-switch topology. 2. The step-up three-phase electric driver according to claim 1, is characterized in that, during normal operation, the outer loop of rotation speed is adopted, and the inner loop of current is double-closed loop operation, wherein the rotation speed loop collects the motor rotation speed, and makes a difference with the reference rotation speed to input PI. The regulator outputs the reference value of the q-axis current; the current loop collects the three-phase current and the electrical angle of the motor, and obtains d through Park transformation

The q-axis current is respectively different from the reference values of the d and q-axis currents, and is input to the PI regulator to output the reference values of the d and q-axis voltages. After Park inverse transformation, the reference values of the α and β-axis voltages are obtained.

, input the SVPWM control module to generate 6-channel signals to control the on-off of the IGBT gate; In fault-tolerant operation, the outer loop of voltage and speed is used, and the inner loop of current is three closed-loop operation. The speed loop and current loop are the same as those in normal operation. The voltage reference value in the voltage loop is twice that of the DC side capacitor voltage in normal operation, which is the same as the collected data. The voltage difference of the DC side capacitor is input to the PI regulator, and the intermediate variable Tz is output, which is input to the SVPWM module. The PI module continuously adjusts the value of Tz until the DC side capacitor voltage Udc rises to twice the original value, completing the fault-tolerant control. 3. A fault-tolerant control method for a boosted three-phase electric driver, wherein the fault-tolerant control is completed based on the boosted three-phase electric driver according to any one of claims 1-2, comprising the steps of: Step 1. Establish the basic voltage vector under no fault condition; Step 2. According to the position of the fault switch tube, switch the topology of the boosted three-phase electric driver; Step 3. Reconstruct the basic voltage vector in the case of a single-tube or single-phase fault; Step 4. Use a 4-sector division method to divide the sectors; Step 5. Select the action vector from the reconstructed basic voltage vector, and determine the corresponding action time; Step 6. Determine the on-time of each switch tube after the boost-type three-phase electric driver reconstructs the topology; Step 7, modulate the on-time of the switch tube with the triangular carrier wave, output the PWM pulse signal of the switch tube, and complete the fault-tolerant control. 4. The fault-tolerant control method for a boosted three-phase electric driver according to claim 3, characterized in that, in step 1, a basic voltage vector is established under no fault condition, as shown in Table 1: Table 1 Fault-free basic voltage vector table

(Sa Sb Sc) is the switching function of the bridge arms of the a, b and c phases. The function value is "1", which means that the upper bridge arm switch of this phase is turned on, and "0" means that the lower bridge wall switch of this phase is turned on. The different switch state combinations of the switch tubes correspond to 8 basic voltage vectors respectively: U0 (000), U1 (100), U2 (110), U3 (010), U4 (011), U5 (001), U6 (101) ), U7(111), Ua, Ub, Uc in the table are the three-phase phase voltage of the three-phase driver, Uk is the basic voltage vector obtained after the three-phase voltage of a, b, c after Clark transformation, k is 0~7, Udc is the DC side capacitor voltage. 5. The fault-tolerant control method for a boosted three-phase electric driver according to claim 3, wherein in step 2, according to the position of the fault switch tube, the topology structure of the boosted three-phase electric driver is switched, and the specific method is: When a phase fails, the boosted three-phase electric driver is controlled by the four switches of the b and c phases. When the b phase fails, the boosted three-phase electric driver is controlled by the four switches of the c and a phases, and the c phase When there is a fault, the step-up three-phase electric driver is controlled by the four switches of the a and b phases. Since the fault includes 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 Triac actions corresponding to open-circuit faults of different switches

When a short-circuit fault occurs in the switch tube, the fast fuse corresponding to the switch tube is blown, and the short-circuit fault is converted into an open-circuit fault. The actions of the bidirectional thyristor and the fast fuse corresponding to the short-circuit fault are shown in Table 3; Table 3 Triac and fast fuse actions corresponding to short-circuit faults of different switches

. 6. The fault-tolerant control method for a boosted three-phase electric driver according to claim 5, wherein in step 3, the basic voltage vector in the case of a single-tube or single-phase fault is reconstructed, and the specific method is: Determine the relationship between the motor phase voltage and the switching state:

In the formula, Ua, Ub, Uc are the three-phase phase voltages of the three-phase driver, Sa, Sb, and Sc represent the switching states of the power devices on the bridge arms of a, b, and c, respectively. When equal to "1", it means that the upper tube is turned on and the lower tube is turned off , when it is equal to "0", it means that the lower tube is turned on and the upper tube is turned off; when the a phase fails, the motor winding a phase is connected to the midpoint of the capacitor, and Sa is always 1/2; the step-up three-phase electric drive is driven by b and c phases. The four switches are controlled by (Sb Sc)=(0 0), (Sb Sc)=(0 1), (Sb Sc)=(1 0), (Sb Sc)=(1 1) 4 switches state; when the b-phase fails, the motor winding b-phase is connected to the midpoint of the capacitor, Sb is always 1/2, the boost three-phase electric driver is controlled by the four switch tubes of c and a phases, with (Sc Sa)= (0 0), (Sc Sa)=(0 1), (Sc Sa)=(1 0), (Sc Sa)=(1 1) 4 switch states; when the c-phase fails, the motor winding c-phase is connected At the midpoint of the capacitor, Sc is always 1/2. The boosted three-phase electric driver is controlled by the four switches of the a and b phases, with (Sa Sb)=(0 0), (Sa Sb)=(0 1 ), (Sa Sb)=(1 0), (Sa Sb)=(1 1) 4 switch states; Determine the three-phase composite voltage space vector:

in the formula

is the spatial rotation factor; Determine the basic voltage vector for reconstructed single-tube or single-phase fault conditions, as shown in Table 4; Table 4 Reconstructed basic voltage vector table

Due to the failure of one of the three phases a, b and c, the four basic voltage vectors U0', U1', U2', U3' are clockwise in the plane according to U0', U1', U3', U2' Sorting, each adjacent vector is separated by 90°, in order to simplify the calculation of the reference vector after unifying the faults of each phase, let the coordinate axis

',

'The positive direction is the positive direction of the basic voltage vector U0', U2', the reference vector

exist

',

' The projection on the axis is

,

. 7. The fault-tolerant control method for a boosted three-phase electric driver according to claim 6, wherein in step 4, a four-sector division method is adopted to divide the sectors, and the specific method is: Define the function:

;

Define the sector calculation value N:

Determine the correspondence between N and the actual sector number through Table 5, and complete the sector division; Table 5 The calculated value of N and the corresponding relationship table of sectors

. 8. The fault-tolerant control method for a boosted three-phase electric driver according to claim 7, wherein in step 5, an action vector is selected from the reconstructed basic voltage vector, and a corresponding action time is determined, and the specific method is: Step 5.1, select the action vector from the reconstructed basic voltage vector; The action vector includes an effective vector and a zero vector. The basic voltage vectors U0'~U3' are used as effective vectors alone, and two basic voltage vectors in opposite directions are used to synthesize an equivalent zero vector, that is, U0' (00), U3' (11 ) to synthesize an equivalent zero vector, and use U1'(01) and U2'(10) to synthesize another equivalent zero vector; combine the effective vector and the equivalent zero vector to synthesize the reference vector; Considering the minimum switching loss, when the reference vector is located in the first sector, the basic voltage vector action sequence is selected as U2', U0', U1', U3'; when the reference vector is in the second sector, the basic voltage vector action sequence is selected. The sequence is U3', U2', U0', U1'; when the reference vector is in the third sector, the basic voltage vector action sequence is U1', U3', U2', U0'; when the reference vector is in the fourth sector In the area, select the basic voltage vector action sequence as U0', U1', U3', U2'; Step 5.2, determine the action time of the action vector; Define intermediate variables:

where Ts is the switching period; Suppose the effective vectors of the first sector are U0', U2', and the action times are Tx and Ty respectively; the effective vectors of the second sector are U2', U3', and the action times are Tx and Ty respectively; the third sector The effective vectors of the zone action are U3', U1', and the action time is Tx, Ty respectively; the effective vector of the fourth sector action is U1', U0', the action time is Tx, Ty respectively; Determine each sector through Table 6 The action time of the effective vector; Table 6 Action time of effective vector of each sector

Define the action time of the equivalent zero vector: T0=Ts-Tx-Ty Since the equivalent zero vector of each sector is synthesized by U0', U1', U2', U3', the intermediate variables are defined: 0<=Tz<=T0 The action time of the two basic voltage vectors of the synthetic equivalent zero vector is equal, then the action time of U1', U2' is

,

; The action time of U0', U3' is

,

; Determine the basic voltage vector action time of each sector according to Table 7: Table 7 Basic voltage vector action time of each sector

. 9. The fault-tolerant control method for a boost-type three-phase electric driver according to claim 3, wherein in step 6, the on-time of each switch tube after the topology of the boost-type three-phase electric driver is reconfigured is determined, and the specific method is as follows: for: Table 8 Switching time points of each switch after topology reconstruction

In one switching cycle, the switching time point of each switch tube after the topology is reconstructed is determined by Table 8. In the table, the values of M and N are a, b, and c. When M=a, b, and c, the corresponding of N = b, c, a; The turn-on time points and turn-off time points of the M and N phases represent the turn-on and turn-off times of the upper switch tubes of the M and N phases, the turn-on and turn-off states of the lower switch tubes of the phase and the upper switch tubes of the phase Tubes are complementary. 10. The fault-tolerant control method for a boost-type three-phase electric driver according to claim 3, characterized in that, in step 7, the on-time of the switching tube and the triangular carrier are modulated, and the PWM pulse signal of the switching tube is output to complete the fault-tolerant control, The specific method is: The DPWM technology is used to modulate the triangular carrier whose on and off time and period are the switching period of the switch, and the dead time is added according to the on and off time of the power switch to obtain the PWM pulse; The 4-way PWM pulse is applied to the power switch tube drive circuit, and the drive circuit controls the corresponding power switch tube to be turned on and off; Collect the DC voltage of the capacitor side, make a difference with the reference voltage and input it to the PI controller, output the intermediate variable Tz, and use Tz as the input of the time module of each sector vector action time, which plays the function of adjusting the DC side capacitor voltage until the DC side capacitor voltage reaches The reference value is used to complete the fault-tolerant control of the electric drive system.

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