Fault-tolerant control method of twelve-phase permanent magnet synchronous motor for flywheel energy storage

Abstract

The invention discloses a fault-tolerant control method of a twelve-phase permanent magnet synchronous motor for flywheel energy storage. The fault-tolerant control method comprises the following steps: step 1, constructing twelve H-bridge driving circuits; step 2, constructing a reconstruction loop on the H-bridge driving circuit for dual-power-supply switching driving; 3, constructing a first loop on the first side of the motor stator winding to absorb the back electromotive force of the first side of the motor stator winding; 4, constructing a second loop on the second side of the motor stator winding for absorbing the back electromotive force of the second side of the motor stator winding; 5, constructing a third loop between the positive electrode of the DC bus of the H-bridge driving circuit and the two sides of the motor stator winding to provide a power supply follow current loop; when the H-bridge driving circuit breaks down, fault line removal is carried out through the first loop, the second loop, the third loop, the reconstruction loop and the double-direct-current power source, and follow current support is provided for the motor. According to the invention, the defect that the control effect is sacrificed because normal operation cannot be realized or only star connection control is adopted when a fault occurs is overcome.

Description

Technical Field

[0001] This invention relates to the field of control technology for permanent magnet synchronous motors, and more specifically, to a fault-tolerant control method for a twelve-phase permanent magnet synchronous motor for flywheel energy storage. Background Technology

[0002] Flywheel energy storage is a technology that uses a high-speed rotating flywheel to store energy. During the storage phase, an electric motor drives the flywheel, accelerating it to a certain speed and converting electrical energy into kinetic energy. During the energy release phase, the flywheel decelerates, driving the electric motor to act as a generator, converting kinetic energy back into electrical energy. A typical flywheel energy storage device generally includes a high-speed rotating flywheel, a sealed housing and bearing system, and a power conversion and control system.

[0003] In recent years, multiphase motors have been widely used. Compared with traditional three-phase motors, they can increase system power, and the control methods of multiphase motors offer greater freedom, simplifying converter design (involving power electronic devices). Furthermore, the increased order and reduced amplitude of the spatial harmonic magnetomotive force generated by the stator excitation of multiphase motors reduce rotor losses, thus improving efficiency compared to three-phase motors. Therefore, it is necessary to apply multiphase motors, especially twelve-phase permanent magnet synchronous motors, to flywheel energy storage systems. However, due to the large number of phases in multiphase motors, reliability needs improvement, and ensuring system operation during failures is a hot research topic. Existing technology CN103457503A—Reconfigurable Fault-Tolerant Drive Topology for Redundant Power Supply—discloses a fault-tolerant control drive topology based on reconfiguration technology. However, this technology can only achieve fault-tolerant control by reconfiguring the star-shaped drive circuit, failing to demonstrate the characteristics and advantages of multiphase motors during fault-tolerant operation. Summary of the Invention

[0004] One object of the present invention is to solve at least the above-mentioned problems and to provide at least the advantages that will be described later.

[0005] Another objective of this invention is to provide a fault-tolerant control method for a 12-phase permanent magnet synchronous motor for flywheel energy storage, which solves the drawback that when the drive circuit of the 12-phase permanent magnet synchronous motor fails, it cannot operate normally or can only be converted to star connection control, thus sacrificing the control effect.

[0006] To achieve these objectives and other advantages according to the present invention, a fault-tolerant control method for a twelve-phase permanent magnet synchronous motor for flywheel energy storage is provided, comprising the following steps: Step 1: Construct twelve H-bridge driver circuits, and set a DC power supply on each side of the H-bridge driver circuit; Step 2: Construct reconfiguration loops on the twelve H-bridge drive circuits for dual power supply switching drive; Step 3: Construct a first circuit on the first side of the motor stator winding to absorb the back electromotive force on the first side of the motor stator winding; Step 4: Construct a second circuit on the second side of the motor stator winding to absorb the back electromotive force on the second side of the motor stator winding; Step 5: Construct a third circuit between the positive terminal of the DC bus of the H-bridge drive circuit and both sides of the motor stator winding to provide a power freewheeling circuit; When the H-bridge drive circuit fails, the faulty line is disconnected and the motor is provided with freewheeling support through the first to third circuits, the reconfiguration circuit, and the dual DC power supply.

[0007] Preferably, each H-bridge drive circuit consists of four power transistors, with two power transistors connected in series to form an upper and lower bridge arm, and the motor stator windings connected between the two upper and lower bridge arms; each upper bridge arm is equipped with a fuse. The first DC power supply VDC is connected to the upper and lower bridge arms on the first side of the H-bridge drive circuit. The second DC power supply E is a battery pack. An energy storage capacitor Cq is connected in parallel on both sides of the second DC power supply E. The second DC power supply E is connected to the upper and lower bridge arms on the second side of the H-bridge drive circuit. A fuse is provided on the connection line between the DC power supply and the H-bridge drive circuit.

[0008] Preferably, the reconfiguration circuit includes a first switch group disposed on the connection line between the first DC power supply VDC and the H-bridge drive circuit, a second switch group disposed on the connection line between the second DC power supply E and the H-bridge drive circuit, and a third switch group disposed on the DC bus between the upper and lower bridge arms on the first side and the upper and lower bridge arms on the second side of the H-bridge drive circuit.

[0009] Preferably, the first switch group includes switch T1 and switch T2. The collector of switch T1 is connected to the positive terminal of the first DC power supply VDC through fuse Fa, and the emitter of switch T1 is connected to the positive terminal of the DC bus of the upper and lower bridge arms of the first side of the H-bridge drive circuit. The emitter of switch T2 is connected to the negative terminal of the first DC power supply VDC, and the collector of switch T2 is connected to the negative terminal of the DC bus of the upper and lower bridge arms of the first side of the H-bridge drive circuit. The second switch group includes switch T3 and switch T4. The collector of switch T3 is connected to the positive terminal of the second DC power supply E through fuse Fb, and the emitter of switch T3 is connected to the positive terminal of the DC bus of the upper and lower bridge arms on the second side of the H-bridge drive circuit. The emitter of switch T4 is connected to the negative terminal of the second DC power supply E, and the collector of switch T4 is connected to the negative terminal of the DC bus of the upper and lower bridge arms on the second side of the H-bridge drive circuit. The third switch group includes diode D1 and switch T5, diode D2 and switch T6, diode D3 and switch T7, and diode D4 and switch T8 connected in series. The anode of diode D1 is connected to the positive terminal of the DC bus of the upper and lower arms of the second side of the H-bridge drive circuit, the cathode of diode D1 is connected to the collector of switch T5, and the emitter of switch T5 is connected to the positive terminal of the DC bus of the upper and lower arms of the first side of the H-bridge drive circuit. The anode of diode D2 is connected to the emitter of switch T5, the cathode of diode D2 is connected to the collector of switch T6, and the emitter of switch T6 is connected to the anode of diode D1. The anode of diode D3 is connected to the negative terminal of the DC bus of the upper and lower arms of the second side of the H-bridge drive circuit, the cathode of diode D3 is connected to the collector of switch T7, and the emitter of switch T7 is connected to the negative terminal of the DC bus of the upper and lower arms of the first side of the H-bridge drive circuit. The anode of diode D4 is connected to the emitter of switch T7, the cathode of diode D4 is connected to the collector of switch T8, and the emitter of switch T8 is connected to the anode of diode D3.

[0010] Preferably, a first circuit is respectively provided between the first side of each motor stator winding and the cathode of diode D3. The first circuit includes diode D12 and switch Tw connected in series, diode D9 and switch Tr connected in series, diode D8 and switch Tm connected in series, diode D10 and switch Ts connected in series, diode D14 and absorption capacitor C2 connected in series, and switch T9 connected in series. The positive terminal of absorption capacitor C2 is connected to the cathode of diode D14. The anode of diode D14, the anode of diode D12, and the emitter of switch Tm are all connected to the first side of the motor stator winding. The cathode of diode D12 is connected to the collector of switch Tw. The anode of diode D9 is connected to the emitter of switch Tw, the negative terminal of absorption capacitor C2, the anode of diode D8, and the emitter of switch Ts. The cathode of diode D9 is connected to the collector of switch Tr. The collector of switch Ts is connected to the cathode of diode D10. The emitter of switch Tr and the anode of diode D10 are all connected to the cathode of diode D3. The collector of switch T9 is connected to the positive terminal of absorption capacitor C2, and the emitter of switch T9 is connected to the positive terminal of energy storage capacitor Cq.

[0011] Preferably, a second circuit is provided between the second side of each motor stator winding and the cathode of diode D3. The second circuit includes diode D13 and switch Tk connected in series, diode D5 and switch Tp connected in series, diode D6 and switch Tq connected in series, diode D11 and switch Tu connected in series, diode D15 and absorption capacitor C1 connected in series, and switch T10 connected in series. The positive terminal of absorption capacitor C1 is connected to the cathode of diode D15. The anodes of diode D15, diode D13, and switch Tq are all connected to the second side of the motor stator winding. The cathode of diode D13 is connected to the collector of switch Tk. Diode D5's anode is connected to the emitter of switch Tk, the cathode of absorption capacitor C1, the anode of diode D6, and the emitter of switch Tu. Diode D6's cathode is connected to the collector of switch Tq. Switch T10's collector is connected to the anode of absorption capacitor C1, and switch T10's emitter is connected to the anode of energy storage capacitor Cq. Diode D5's cathode is connected to the collector of switch Tp. Diode D11's cathode is connected to the collector of switch Tu. Switch Tp's emitter and diode D11's anode are both connected to diode D3's cathode. Diode D3's cathode is connected to the cathode of energy storage capacitor Cq through switch T11, and switch T11's collector is connected to the cathode of energy storage capacitor Cq.

[0012] Preferably, the third circuit includes a fuse Fs1 and a switch T31 ​​connected in series, and a fuse Fs2 and a switch T32 connected in series. The collector of switch T31 ​​is connected to the positive terminal of the second DC bus of the H-bridge drive circuit through fuse Fs1, and the emitter of switch T31 ​​is connected to the cathode of diode D3. The collector of switch T32 is connected to the positive terminal of the first DC bus of the H-bridge drive circuit through fuse Fs2, and the emitter of switch T32 is connected to the cathode of diode D3.

[0013] Preferably, during normal operation, the circuit is powered by a single-sided or double-sided DC power supply. When the upper bridge arm of the first side of the H-bridge drive circuit is turned off and the lower bridge arm of the second side of the H-bridge drive circuit is turned off, the switches Ts, Tm, and Tp on the first and second circuits corresponding to the phases are closed. The back electromotive force on the second side of the stator winding flows back to the first side of the stator winding through the absorption capacitor C1, the switches Tp, Ts, and Tm in sequence, and is absorbed by the absorption capacitor C1. When the lower bridge arm on the first side of the H-bridge drive circuit is turned off and the upper bridge arm on the second side of the H-bridge drive circuit is turned off, the switches Tr, Tu, and Tq on the first and second circuits of the corresponding phases are closed. The back electromotive force on the first side of the stator winding flows back to the second side of the stator winding through the absorption capacitor C2, the switches Tr, Tu, and Tq in sequence, and is absorbed by the absorption capacitor C2. When the energy storage voltage on the absorption capacitors C1 and C2 reaches the set value, the switches T9-T11 are closed periodically to charge the energy stored on the absorption capacitors C1 and C2 to the energy storage capacitor Cq and the second DC power supply E.

[0014] Preferably, when a short circuit fault occurs in the upper arm of the first side of the H-bridge drive circuit, the switches Tw, Tm, Tr, and Ts on each of the first circuits are closed to short-circuit the first side of the motor stator winding. The H-bridge drive circuit is switched to a star-connected drive circuit. Switches T3 and T4 are closed to supply power through the second DC power supply E. The upper arm of the second side of the H-bridge drive circuit is driven to close and close according to the control logic, and the motor is controlled to drive the flywheel to rotate and store energy. Alternatively, when current flows from the first side to the second side of the stator winding, switch T31 ​​is closed, and power is supplied through the second DC power supply E. According to the control logic, switches Ts and Tm on the first circuit and the lower bridge arm on the second side of the H-bridge drive circuit are closed and closed. When current flows from the second side to the first side of the stator winding, power is supplied through the second DC power supply E, switch T8 is closed, and according to the control logic, the upper bridge arm on the second side and the lower bridge arm on the first side of the H-bridge drive circuit are closed and closed. This controls the motor to drive the flywheel to rotate and store energy. When a short circuit fault occurs in the lower bridge arm on the first side of the H-bridge drive circuit, the switches Tw, Tm, Tr, and Ts on each of the first circuits are closed to short-circuit the first side of the motor stator winding. The H-bridge drive circuit is switched to a star-connected drive circuit. Switches T3 and T4 are closed to supply power through the second DC power supply E. The upper bridge arm on the second side of the H-bridge drive circuit is driven to close and close according to the control logic, and the motor is controlled to drive the flywheel to rotate and store energy. When a short circuit fault occurs in both the upper and lower arms of the first side of the H-bridge drive circuit, the H-bridge drive circuit is switched to a star-connected drive circuit for control.

[0015] Preferably, when an open circuit fault occurs in the upper arm of the first side of the H-bridge drive circuit, at least one of the switches T31 and T32 is closed, and the switches Ts and Tm on the first circuit of the faulty phase are used to replace the open circuit arm function, and the motor is controlled to drive the flywheel to rotate and store energy. When a circuit failure occurs in the lower arm of the first side of the H-bridge drive circuit, switches T7 and T8 remain closed. Switches Tw and Tr on the first circuit of the faulty phase replace the function of the broken arm and control the motor to drive the flywheel to rotate and store energy.

[0016] The present invention has at least the following beneficial effects: 1. This invention improves the reliability of the drive circuit by using dual-side power supplies and H-bridge dual-side drive circuits. Even if either side of the power supply fails, the normal operation of the drive circuit can be guaranteed, thereby improving the operational stability of the flywheel energy storage system.

[0017] 2. Three protection circuits are constructed on the dual-side drive circuit of the H-bridge. As long as the dual-side drive circuit does not fail simultaneously, the normal operation of the drive circuit can be guaranteed, and the drive control performance can be effectively guaranteed to give full play to the driving advantages of the twelve-phase permanent magnet synchronous motor.

[0018] 3. During normal operation of the drive circuit, the first and second circuits effectively absorb the back electromotive force generated by the turn-off of the upper and lower bridge arms of the drive circuit, providing a freewheeling and absorption circuit for the back electromotive force, reducing the impact on the main drive circuit, and improving drive control performance. Furthermore, the absorbed back electromotive force can be absorbed and stored through the first and second circuits and fed back to the energy storage battery on the second side, realizing the functions of absorption and utilization, saving energy and ensuring system operational stability.

[0019] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0020] Figure 1 This is a topology diagram of the system of the present invention; Figure 2 This is a schematic diagram of the first loop. Figure 3 This is a schematic diagram of the second loop. Figure 4 This is a flowchart of the fault-tolerant control process of the present invention. Detailed Implementation

[0021] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0022] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not imply the presence or addition of one or more other elements or combinations thereof.

[0023] like Figure 1-4 As shown, this invention provides a fault-tolerant control method for a twelve-phase permanent magnet synchronous motor for flywheel energy storage, comprising the following steps: Step 1: Construct twelve H-bridge drive circuits. Each H-bridge drive circuit consists of four power transistors (power electronic devices). Every two power transistors are connected in series to form an upper and lower bridge arm. The motor stator windings Ph1-Ph12 are connected between the two upper and lower bridge arms. Each upper bridge arm is equipped with fuses F1a-F12a and F1b-F12b. The H-bridge drive circuit is existing technology and will not be described in detail in this invention. This invention only shows the four-phase electronic windings and the corresponding H-bridge circuits. A DC power supply is set on each side of the H-bridge drive circuit. The first DC power supply VDC is connected to the upper and lower bridge arms on the first side of the H-bridge drive circuit. The second DC power supply E is a battery pack, which is connected to the upper and lower bridge arms on the second side of the H-bridge drive circuit. To prevent operation failure due to grid power outages, battery packs can also be configured on both sides as needed. An energy storage capacitor Cq is connected in parallel across the second DC power supply E to increase the energy storage capacity on the second side of the H-bridge drive circuit and to ensure voltage stability on the second DC power supply E while charging it.

[0024] The DC power supply and the H-bridge drive circuit are connected by fuses Fa and Fb.

[0025] Step 2: Construct a reconfiguration loop on the twelve H-bridge drive circuits for dual power supply switching drive; the reconfiguration loop includes a first switch group T1 and T2 set on the connection line between the first DC power supply VDC and the H-bridge drive circuit, a second switch group T3 and T4 set on the connection line between the second DC power supply E and the H-bridge drive circuit, and a third switch group T4-T8 and D1-D4 set on the DC bus between the upper and lower bridge arms on the first side and the upper and lower bridge arms on the second side of the H-bridge drive circuit.

[0026] Specifically, the first switch group includes switch T1 and switch T2. The collector of switch T1 is connected to the positive terminal of the first DC power supply VDC through fuse Fa, and the emitter of switch T1 is connected to the positive terminal of the DC bus of the upper and lower bridge arms of the first side of the H-bridge drive circuit. The emitter of switch T2 is connected to the negative terminal of the first DC power supply VDC, and the collector of switch T2 is connected to the negative terminal of the DC bus of the upper and lower bridge arms of the first side of the H-bridge drive circuit. The first switch group is used to control whether the first DC power supply VDC is switched on for power supply.

[0027] Similarly, the second switch group includes switch T3 and switch T4. The collector of switch T3 is connected to the positive terminal of the second DC power supply E through fuse Fb, and the emitter of switch T3 is connected to the positive terminal of the DC bus of the upper and lower bridge arms on the second side of the H-bridge drive circuit. The emitter of switch T4 is connected to the negative terminal of the second DC power supply E, and the collector of switch T4 is connected to the negative terminal of the DC bus of the upper and lower bridge arms on the second side of the H-bridge drive circuit. The second switch group is used to control whether the second DC power supply E is switched on for power supply.

[0028] The third switch group includes diode D1 and switch T5, diode D2 and switch T6, diode D3 and switch T7, and diode D4 and switch T8 connected in series. The anode of diode D1 is connected to the positive terminal of the DC bus of the upper and lower arms of the second side of the H-bridge drive circuit, the cathode of diode D1 is connected to the collector of switch T5, and the emitter of switch T5 is connected to the positive terminal of the DC bus of the upper and lower arms of the first side of the H-bridge drive circuit. The anode of diode D2 is connected to the emitter of switch T5, the cathode of diode D2 is connected to the collector of switch T6, and the emitter of switch T6 is connected to the anode of diode D1. The anode of diode D3 is connected to the negative terminal of the DC bus of the upper and lower arms of the second side of the H-bridge drive circuit, the cathode of diode D3 is connected to the collector of switch T7, and the emitter of switch T7 is connected to the negative terminal of the DC bus of the upper and lower arms of the first side of the H-bridge drive circuit. The anode of diode D4 is connected to the emitter of switch T7, the cathode of diode D4 is connected to the collector of switch T8, and the emitter of switch T8 is connected to the anode of diode D3.

[0029] The third switch group provides bidirectional flow control for the H-bridge. When the first DC power supply VDC is powered by a single power source, control switches T1, T2, T6, and T7 are closed. When the second DC power supply E is powered by a single power source, control switches T3, T4, T5, and T8 are closed. When both the first DC power supply VDC and the second DC power supply E are powered by a single power source, control switches T1-T4, T7, and T8 are closed.

[0030] Step 3: Construct a first circuit 21-24... on the first side of the motor stator winding to absorb the back electromotive force on the first side of the motor stator winding; Specifically, a first circuit is respectively set between the first side of each motor stator winding and the cathode of diode D3. The first circuit includes diode D12 and switch Tw connected in series, diode D9 and switch Tr connected in series, diode D8 and switch Tm connected in series, diode D10 and switch Ts connected in series, diode D14 and absorption capacitor C2 connected in series, and switch T9 connected in series. The positive terminal of absorption capacitor C2 is connected to the cathode of diode D14. The anode of diode D14, the anode of diode D12, and the emitter of switch Tm are all connected to the first side of the motor stator winding. The cathode of diode D12 is connected to the collector of switch Tw. The anode of diode D9 is connected to the emitter of switch Tw, the negative terminal of absorption capacitor C2, the anode of diode D8, and the emitter of switch Ts. The cathode of diode D9 is connected to the collector of switch Tr. The collector of switch Ts is connected to the cathode of diode D10. The emitter of switch Tr and the anode of diode D10 are all connected to the cathode of diode D3. The collector of switch T9 is connected to the positive terminal of absorption capacitor C2. The emitter of switch T9 is connected to the positive terminal of energy storage capacitor Cq.

[0031] Step 4: Construct a second circuit 11-14... on the second side of the motor stator winding to absorb the back electromotive force on the second side of the motor stator winding; Specifically, a second circuit is respectively set between the second side of each motor stator winding and the cathode of diode D3. The second circuit includes diode D13 and switch Tk connected in series, diode D5 and switch Tp connected in series, diode D6 and switch Tq connected in series, diode D11 and switch Tu connected in series, diode D15 and absorption capacitor C1 connected in series, and switch T10 connected in series. The positive terminal of absorption capacitor C1 is connected to the cathode of diode D15. The anodes of diode D15, diode D13, and switch Tq are all connected to the second side of the motor stator winding. The cathode of diode D13 is connected to the collector of switch Tk. Diode D5's anode is connected to the emitter of switch Tk, the cathode of absorption capacitor C1, the anode of diode D6, and the emitter of switch Tu. Diode D6's cathode is connected to the collector of switch Tq. Switch T10's collector is connected to the anode of absorption capacitor C1, and switch T10's emitter is connected to the anode of energy storage capacitor Cq. Diode D5's cathode is connected to the collector of switch Tp. Diode D11's cathode is connected to the collector of switch Tu. Switch Tp's emitter and diode D11's anode are both connected to diode D3's cathode. Diode D3's cathode is connected to the cathode of energy storage capacitor Cq through switch T11, and switch T11's collector is connected to the cathode of energy storage capacitor Cq.

[0032] During normal operation, the circuit is powered by a single or double DC power supply, preferably a second DC power supply E or a dual-side synchronous power supply. As the second DC power supply E is consumed, the back electromotive force absorbed in the circuit can be fed back to charge the circuit, thus forming a dynamic balance.

[0033] When the upper bridge arm on the first side of the H-bridge drive circuit is turned off and the lower bridge arm on the second side of the H-bridge drive circuit is turned off, the switches Ts, Tm, and Tp on the first and second circuits corresponding to the phases are closed. The back electromotive force on the second side of the stator winding flows back to the first side of the stator winding through the absorption capacitor C1, the switches Tp, Ts, and Tm in sequence, and is absorbed by the absorption capacitor C1. When the lower bridge arm on the first side of the H-bridge drive circuit is turned off and the upper bridge arm on the second side of the H-bridge drive circuit is turned off, the switches Tr, Tu, and Tq on the first and second circuits of the corresponding phases are closed. The back electromotive force on the first side of the stator winding flows back to the second side of the stator winding through the absorption capacitor C2, the switches Tr, Tu, and Tq in sequence, and is absorbed by the absorption capacitor C2. When the energy storage voltage on the absorption capacitors C1 and C2 reaches the set value, the switches T9-T11 are closed periodically to charge the energy stored on the absorption capacitors C1 and C2 to the energy storage capacitor Cq and the second DC power supply E.

[0034] Therefore, it can be seen that during normal operation of the drive circuit, the first and second circuits can effectively absorb the back electromotive force generated by the turn-off of the upper and lower bridge arms of the drive circuit, providing a freewheeling and absorption circuit for the back electromotive force, reducing the impact on the main drive circuit, and improving drive control performance. Furthermore, the absorbed back electromotive force can be absorbed and stored through the first and second circuits and fed back to the energy storage battery on the second side, realizing the absorption and utilization function, saving energy and ensuring system stability. When the H-bridge drive circuit fails, the first and second circuits only provide a freewheeling function, and the absorption capacitors C1 and C2 no longer absorb the back electromotive force until the drive circuit resumes normal operation; in this case, the first and second circuits only provide the function of absorbing the back electromotive force.

[0035] Step 5: Construct a third circuit between the positive terminal of the DC bus of the H-bridge drive circuit and both sides of the motor stator winding to provide a power freewheeling circuit; The third circuit includes a fuse Fs1 and a switch T31 ​​connected in series, and a fuse Fs2 and a switch T32 connected in series. The collector of switch T31 ​​is connected to the positive terminal of the second DC bus of the H-bridge drive circuit through fuse Fs1, and the emitter of switch T31 ​​is connected to the cathode of diode D3. The collector of switch T32 is connected to the positive terminal of the first DC bus of the H-bridge drive circuit through fuse Fs2, and the emitter of switch T32 is connected to the cathode of diode D3.

[0036] When the H-bridge drive circuit fails, the faulty line is disconnected and the motor is provided with freewheeling support through the first to third circuits, the reconfiguration circuit, and the dual DC power supply.

[0037] When the H-bridge drive circuit is short-circuited: Specifically, when a short circuit fault occurs in the upper arm of the first side of the H-bridge drive circuit, the switches Tw, Tm, Tr, and Ts on each of the first circuits are closed to short-circuit the first side of the motor stator winding. The H-bridge drive circuit switches to a star connection drive circuit. Switches T3 and T4 are closed, and power is supplied through the second DC power supply E. According to the control logic, the upper arm of the second side of the H-bridge drive circuit is driven to close and close, and the motor is controlled to drive the flywheel to rotate and store energy. The star connection drive circuit can provide basic operational protection, but its control effect is not as good as the control advantage of a normal twelve-phase H-bridge drive circuit.

[0038] Alternatively, when current flows from the first side to the second side of the stator winding, switch T31 ​​is closed, and power is supplied through the second DC power supply E. According to the control logic, switches Ts and Tm on the first circuit and the lower bridge arm on the second side of the H-bridge drive circuit are closed and closed. When current flows from the second side to the first side of the stator winding, power is supplied through the second DC power supply E, switch T8 is closed, and according to the control logic, the upper bridge arm on the second side and the lower bridge arm on the first side of the H-bridge drive circuit are closed and closed. This controls the motor to drive the flywheel to rotate and store energy. Switch T31 ​​and the first circuit replace the function of the faulty upper bridge arm to ensure the normal operation of the twelve-phase H-bridge drive circuit.

[0039] When a short circuit fault occurs in the lower bridge arm on the first side of the H-bridge drive circuit, the switches Tw, Tm, Tr, and Ts on each of the first circuits are closed to short-circuit the first side of the motor stator winding. The H-bridge drive circuit is switched to a star-connected drive circuit. Switches T3 and T4 are closed to supply power through the second DC power supply E. The upper bridge arm on the second side of the H-bridge drive circuit is driven to close and close according to the control logic, and the motor is controlled to drive the flywheel to rotate and store energy. When a short circuit fault occurs in both the upper and lower arms of the first side of the H-bridge drive circuit, the H-bridge drive circuit is switched to a star-connected drive circuit for control.

[0040] When a short circuit fault occurs in the second arm of the H-bridge drive circuit, the control logic is the same as when a short circuit fault occurs in the upper arm of the first arm of the H-bridge drive circuit. The difference is that the first DC power supply is used, and switch T32 is used instead of switch T31.

[0041] When the H-bridge drive circuit is open-circuited: Specifically, when an open circuit fault occurs in the upper arm of the first side of the H-bridge drive circuit, at least one of switches T31 and T32 should be closed. For example, in the case of dual power supply drive, one or both of switches T31 and T32 should be closed. In the case of single power supply drive, the switch T31 ​​or T32 on the side where the single power supply is located should be closed. The switch Ts and Tm on the first circuit of the faulty phase should replace the function of the open circuit arm. This ensures the normal operation of the twelve-phase H-bridge drive circuit and controls the motor to drive the flywheel to rotate and store energy.

[0042] When a circuit failure occurs in the lower arm of the first side of the H-bridge drive circuit, switches T7 and T8 remain closed. Switches Tw and Tr on the first circuit of the faulty phase replace the function of the broken arm to ensure the normal operation of the twelve-phase H-bridge drive circuit and control the motor to drive the flywheel to rotate and store energy.

[0043] When an open circuit fault occurs in the second arm of the H-bridge drive circuit, the control strategy is the same as when an open circuit fault occurs in the first arm of the H-bridge drive circuit. The difference is that the function of the faulty arm is replaced by a second circuit.

[0044] In summary, this invention enhances the reliability of the drive circuit through dual-sided power supplies and dual-sided H-bridge drive circuits. Even if one side of the power supply fails, the drive circuit can still operate normally, improving the operational stability of the flywheel energy storage system. Simultaneously, three backup circuits are constructed on the dual-sided H-bridge drive circuit. As long as both sides of the drive circuit do not fail simultaneously, normal operation of the drive circuit can be guaranteed. Only when a short circuit occurs in the lower bridge arm is a star-connected drive circuit required for control. In other single-sided failures, the normal operation of the twelve-phase H-bridge drive circuit can be guaranteed, controlling the motor to drive the flywheel to rotate and store energy. This effectively ensures drive control performance, leveraging the driving advantages of the twelve-phase permanent magnet synchronous motor.

[0045] During normal operation of the drive circuit, the first and second circuits effectively absorb the back electromotive force generated by the turn-off of the upper and lower bridge arms of the drive circuit, providing a freewheeling and absorption circuit for the back electromotive force, reducing the impact on the main drive circuit, and improving drive control performance. Furthermore, the absorbed back electromotive force can be absorbed and stored through the first and second circuits and fed back to the energy storage battery on the second side, realizing the absorption and utilization function, saving energy and ensuring system operational stability.

[0046] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A fault-tolerant control method for a twelve-phase permanent magnet synchronous motor for flywheel energy storage, characterized in that, Includes the following steps: Step 1: Construct twelve H-bridge driver circuits, and set a DC power supply on each side of the H-bridge driver circuit; Step 2: Construct reconfiguration loops on the twelve H-bridge drive circuits for dual power supply switching drive; Step 3: Construct a first circuit on the first side of the motor stator winding to absorb the back electromotive force on the first side of the motor stator winding; Step 4: Construct a second circuit on the second side of the motor stator winding to absorb the back electromotive force on the second side of the motor stator winding; Step 5: Construct a third circuit between the positive terminal of the DC bus of the H-bridge drive circuit and both sides of the motor stator winding to provide a power freewheeling circuit; When the H-bridge drive circuit fails, the faulty line is disconnected and the motor is provided with freewheeling support through the first to third circuits, the reconfiguration circuit, and the dual DC power supply.

2. The fault-tolerant control method for a twelve-phase permanent magnet synchronous motor for flywheel energy storage as described in claim 1, characterized in that, Each H-bridge drive circuit consists of four power transistors, with two power transistors connected in series to form an upper and lower bridge arm. The motor stator winding is connected between the two upper and lower bridge arms. A fuse is provided on each upper bridge arm. The first DC power supply VDC is connected to the upper and lower bridge arms on the first side of the H-bridge drive circuit. The second DC power supply E is a battery pack. An energy storage capacitor Cq is connected in parallel on both sides of the second DC power supply E. The second DC power supply E is connected to the upper and lower bridge arms on the second side of the H-bridge drive circuit. A fuse is provided on the connection line between the DC power supply and the H-bridge drive circuit.

3. The fault-tolerant control method for a twelve-phase permanent magnet synchronous motor for flywheel energy storage as described in claim 2, characterized in that, The reconfiguration circuit includes a first switch group disposed on the connection line between the first DC power supply VDC and the H-bridge drive circuit, a second switch group disposed on the connection line between the second DC power supply E and the H-bridge drive circuit, and a third switch group disposed on the DC bus between the upper and lower bridge arms on the first side and the upper and lower bridge arms on the second side of the H-bridge drive circuit.

4. The fault-tolerant control method for a twelve-phase permanent magnet synchronous motor for flywheel energy storage as described in claim 3, characterized in that, The first switch group includes switch T1 and switch T2. The collector of switch T1 is connected to the positive terminal of the first DC power supply VDC through fuse Fa, and the emitter of switch T1 is connected to the positive terminal of the DC bus of the upper and lower bridge arms of the first side of the H-bridge drive circuit. The emitter of switch T2 is connected to the negative terminal of the first DC power supply VDC, and the collector of switch T2 is connected to the negative terminal of the DC bus of the upper and lower bridge arms of the first side of the H-bridge drive circuit. The second switch group includes switch T3 and switch T4. The collector of switch T3 is connected to the positive terminal of the second DC power supply E through fuse Fb, and the emitter of switch T3 is connected to the positive terminal of the DC bus of the upper and lower bridge arms on the second side of the H-bridge drive circuit. The emitter of switch T4 is connected to the negative terminal of the second DC power supply E, and the collector of switch T4 is connected to the negative terminal of the DC bus of the upper and lower bridge arms on the second side of the H-bridge drive circuit. The third switch group includes diode D1 and switch T5, diode D2 and switch T6, diode D3 and switch T7, and diode D4 and switch T8 connected in series. The anode of diode D1 is connected to the positive terminal of the DC bus of the upper and lower arms of the second side of the H-bridge drive circuit, the cathode of diode D1 is connected to the collector of switch T5, and the emitter of switch T5 is connected to the positive terminal of the DC bus of the upper and lower arms of the first side of the H-bridge drive circuit. The anode of diode D2 is connected to the emitter of switch T5, the cathode of diode D2 is connected to the collector of switch T6, and the emitter of switch T6 is connected to the anode of diode D1. The anode of diode D3 is connected to the negative terminal of the DC bus of the upper and lower arms of the second side of the H-bridge drive circuit, the cathode of diode D3 is connected to the collector of switch T7, and the emitter of switch T7 is connected to the negative terminal of the DC bus of the upper and lower arms of the first side of the H-bridge drive circuit. The anode of diode D4 is connected to the emitter of switch T7, the cathode of diode D4 is connected to the collector of switch T8, and the emitter of switch T8 is connected to the anode of diode D3.

5. The fault-tolerant control method for a twelve-phase permanent magnet synchronous motor for flywheel energy storage as described in claim 4, characterized in that, Each motor stator winding has a first circuit connected between its first side and the cathode of diode D3. The first circuit includes diode D12 and switch Tw connected in series, diode D9 and switch Tr connected in series, diode D8 and switch Tm connected in series, diode D10 and switch Ts connected in series, diode D14 and absorption capacitor C2 connected in series, and switch T9 connected in series. The positive terminal of absorption capacitor C2 is connected to the cathode of diode D14. The anodes of diode D14, D12, and switch Tm are all connected to the first side of the motor stator winding. The cathode of diode D12 is connected to the collector of switch Tw. The anode of diode D9 is connected to the emitter of switch Tw, the negative terminal of absorption capacitor C2, the anode of diode D8, and the emitter of switch Ts. The cathode of diode D9 is connected to the collector of switch Tr. The collector of switch Ts is connected to the cathode of diode D10. The emitter of switch Tr and the anode of diode D10 are all connected to the cathode of diode D3. The collector of switch T9 is connected to the positive terminal of absorption capacitor C2. The emitter of switch T9 is connected to the positive terminal of energy storage capacitor Cq.

6. The fault-tolerant control method for a twelve-phase permanent magnet synchronous motor for flywheel energy storage as described in claim 5, characterized in that, A second circuit is respectively set between the second side of each motor stator winding and the cathode of diode D3. The second circuit includes diode D13 and switch Tk connected in series, diode D5 and switch Tp connected in series, diode D6 and switch Tq connected in series, diode D11 and switch Tu connected in series, diode D15 and absorption capacitor C1 connected in series, and switch T10 connected in series. The positive terminal of absorption capacitor C1 is connected to the cathode of diode D15. The anodes of diode D15, diode D13, and switch Tq are all connected to the second side of the motor stator winding. The cathode of diode D13 is connected to the collector of switch Tk. The anode of diode D5 is connected to the emitter of switch Tk, the cathode of absorption capacitor C1, the anode of diode D6, and the emitter of switch Tu. The cathode of diode D6 is connected to the collector of switch Tq. The collector of switch T10 is connected to the positive terminal of absorption capacitor C1, and the emitter of switch T10 is connected to the positive terminal of energy storage capacitor Cq. The cathode of diode D5 is connected to the collector of switch Tp, and the cathode of diode D11 is connected to the collector of switch Tu. The emitter of switch Tp and the anode of diode D11 are connected to the cathode of diode D3. The cathode of diode D3 is connected to the negative terminal of energy storage capacitor Cq through switch T11, and the collector of switch T11 is connected to the negative terminal of energy storage capacitor Cq.

7. The fault-tolerant control method for a twelve-phase permanent magnet synchronous motor for flywheel energy storage as described in claim 6, characterized in that, The third circuit includes a fuse Fs1 and a switch T31 ​​connected in series, and a fuse Fs2 and a switch T32 connected in series. The collector of switch T31 ​​is connected to the positive terminal of the second DC bus of the H-bridge drive circuit through fuse Fs1, and the emitter of switch T31 ​​is connected to the cathode of diode D3. The collector of switch T32 is connected to the positive terminal of the first DC bus of the H-bridge drive circuit through fuse Fs2, and the emitter of switch T32 is connected to the cathode of diode D3.

8. The fault-tolerant control method for a twelve-phase permanent magnet synchronous motor for flywheel energy storage as described in claim 7, characterized in that, During normal operation, the circuit is powered by a single-sided or double-sided DC power supply. When the upper bridge arm of the first side of the H-bridge drive circuit is turned off and the lower bridge arm of the second side of the H-bridge drive circuit is turned off, the switches Ts, Tm, and Tp on the first and second circuits corresponding to the phases are closed. The back electromotive force on the second side of the stator winding flows back to the first side of the stator winding through the absorption capacitor C1, the switches Tp, Ts, and Tm in sequence, and is absorbed by the absorption capacitor C1. When the lower bridge arm on the first side of the H-bridge drive circuit is turned off and the upper bridge arm on the second side of the H-bridge drive circuit is turned off, the switches Tr, Tu, and Tq on the first and second circuits of the corresponding phases are closed. The back electromotive force on the first side of the stator winding flows back to the second side of the stator winding through the absorption capacitor C2, the switches Tr, Tu, and Tq in sequence, and is absorbed by the absorption capacitor C2. When the energy storage voltage on the absorption capacitors C1 and C2 reaches the set value, the switches T9-T11 are closed periodically to charge the energy stored on the absorption capacitors C1 and C2 to the energy storage capacitor Cq and the second DC power supply E.

9. The fault-tolerant control method for a twelve-phase permanent magnet synchronous motor for flywheel energy storage as described in claim 8, characterized in that, When a short circuit fault occurs in the upper arm of the first side of the H-bridge drive circuit, the switches Tw, Tm, Tr, and Ts on each of the first circuits are closed to short-circuit the first side of the motor stator winding. The H-bridge drive circuit is switched to a star-connected drive circuit. Switches T3 and T4 are closed to supply power through the second DC power supply E. The upper arm of the second side of the H-bridge drive circuit is driven to close and close according to the control logic, and the motor is controlled to drive the flywheel to rotate and store energy. Alternatively, when current flows from the first side to the second side of the stator winding, switch T31 ​​is closed, and power is supplied through the second DC power supply E. According to the control logic, switches Ts and Tm on the first circuit and the lower bridge arm on the second side of the H-bridge drive circuit are closed and closed. When current flows from the second side to the first side of the stator winding, power is supplied through the second DC power supply E, switch T8 is closed, and according to the control logic, the upper bridge arm on the second side and the lower bridge arm on the first side of the H-bridge drive circuit are closed and closed. This controls the motor to drive the flywheel to rotate and store energy. When a short circuit fault occurs in the lower bridge arm on the first side of the H-bridge drive circuit, the switches Tw, Tm, Tr, and Ts on each of the first circuits are closed to short-circuit the first side of the motor stator winding. The H-bridge drive circuit is switched to a star-connected drive circuit. Switches T3 and T4 are closed to supply power through the second DC power supply E. The upper bridge arm on the second side of the H-bridge drive circuit is driven to close and close according to the control logic, and the motor is controlled to drive the flywheel to rotate and store energy. When a short circuit fault occurs in both the upper and lower arms of the first side of the H-bridge drive circuit, the H-bridge drive circuit is switched to a star-connected drive circuit for control.

10. The fault-tolerant control method for a twelve-phase permanent magnet synchronous motor for flywheel energy storage as described in claim 9, characterized in that, When an open circuit fault occurs in the upper arm of the first side of the H-bridge drive circuit, at least one of the switches T31 and T32 is closed, and the switches Ts and Tm on the first circuit of the faulty phase are used to replace the function of the open circuit arm, and the motor is controlled to drive the flywheel to rotate and store energy. When a circuit failure occurs in the lower arm of the first side of the H-bridge drive circuit, switches T7 and T8 remain closed. Switches Tw and Tr on the first circuit of the faulty phase replace the function of the broken arm and control the motor to drive the flywheel to rotate and store energy.

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