CN104201808B - A kind of composite excitation fault-tolerant motor system based on position automatic detection - Google Patents

Abstract

The invention discloses a hybrid excitation fault-tolerant motor system based on position self-detection, which includes a stator, a rotor, a permanent magnet, an armature tooth, a fault-tolerant tooth, an armature coil, and an excitation coil; armature coils are wound on the armature teeth; Coils are set on the stator fault-tolerant teeth; permanent magnets are embedded in the rotor; all permanent magnets form a permanent magnetic field, and all excitation coils form an electric field; One end of the shaft center is spliced together, and one or more slots are opened between a pair of permanent magnet poles in the rotor along the direction of the q-axis magnetic circuit to form one or more magnetic isolation layers. Compared with the traditional permanent magnet synchronous motor, the invention adds a magnetic isolation layer along the direction of the q-axis magnetic circuit in the rotor, which is beneficial to realize zero-low speed operation without position sensor control, and further improves the reliability and fault tolerance of the motor drive system , and it is also beneficial to further improve the torque output of the motor.

Description

A hybrid excitation fault-tolerant motor system based on position self-detection

technical field

The invention relates to a motor, in particular to a hybrid excitation fault-tolerant motor based on position self-detection.

Background technique

The built-in permanent magnet synchronous motor has the advantages of large torque output, wide speed range, high power density and high efficiency, and has been widely used in many high-performance drive fields. In the high-performance drive fields such as new energy electric vehicles, wind power generation and aerospace, high requirements are placed on the reliability of the drive system. The current conventional built-in permanent magnet synchronous motor still has the problem of permanent magnet demagnetization and excitation adjustment difficulties, and does not consider the fault-tolerant performance of the motor, which cannot meet the system reliability requirements and fault-tolerant operation capability.

In addition, in realizing the high-performance control of the motor drive system, it is often necessary to use position sensors to accurately detect the position and speed signals of the motor, but the installation of additional position sensors not only increases the cost of the control system, but also reduces the reliability of the system. sex. In order to solve the problems brought by traditional mechanical sensors to the system, position self-detection technology, that is, position sensorless control technology has become a research hotspot in the field of motor control. The zero-low speed operation of the permanent magnet synchronous motor has always been the main problem in the position sensorless control. The high-frequency signal injection method is very suitable for the zero-low speed operation of the permanent magnet synchronous motor based on position sensorless control, but this method requires the motor to have obvious saliency. Therefore, a reasonable design of the built-in permanent magnet The position sensor operates at zero and low speed, which is more conducive to further improving the fault tolerance performance of the drive motor. Based on the above background, a hybrid excitation fault-tolerant motor drive system based on position self-detection has been developed, which will help meet the above-mentioned requirements for the motor drive system.

Contents of the invention

Technical problem: In view of the above existing technologies and their deficiencies, the present invention intends to propose a hybrid excitation fault-tolerant motor system based on position self-detection, to realize zero-low-speed operation of the motor without position sensor control, and to further improve the reliability and fault-tolerant performance of the motor drive system.

Technical scheme: in order to achieve the above object, the technical scheme adopted in the present invention is:

A hybrid excitation fault-tolerant motor system based on position self-detection, including a stator, a rotor, a permanent magnet, an armature tooth, a fault-tolerant tooth, an armature coil, and an excitation coil; the armature teeth and fault-tolerant teeth are evenly spaced along the inner circle of the stator , and the tooth width of the armature teeth and the tooth width of the fault-tolerant teeth are not equal; the armature teeth are wound with armature coils, which are single-layer concentrated windings, and the fault-tolerant teeth are used to isolate the two adjacent single-layer concentrated windings. The armature coils on the two opposite armature teeth are connected in series to form a phase; the excitation coils are set on the stator fault-tolerant teeth, and the excitation coils are connected in series head to tail to form a set of single-phase concentrated excitation windings; permanent magnets are embedded in the rotor; all permanent magnets constitute Permanent magnetic field, all excitation coils form an electric excitation magnetic field; it is characterized in that: the permanent magnet is composed of two magnetic strips that are radially symmetrical along the rotor at one end close to the rotor axis; in the rotor, a One or more slots are opened between the permanent magnet poles along the direction of the q-axis magnetic circuit to form one or more magnetic isolation layers.

The total number of teeth of armature teeth and fault-tolerant teeth is a multiple of 2m, and the difference between the total number of teeth of armature teeth and fault-tolerant teeth and the number of pole pairs of permanent magnets is ±2, where m is the number of phases of the motor.

The stator and rotor cores are silicon steel sheets, iron, cobalt, nickel and alloys thereof.

The permanent magnet is a permanent magnet material such as NdFeB, rare earth cobalt or alnico.

Non-magnetic materials such as aluminum or copper are arranged in the magnetic isolation layer.

The motor system of the present invention retains the advantages of the traditional built-in permanent magnet synchronous motor in terms of structure and performance, such as large torque output, wide speed range, high power density and high efficiency; This excitation method solves the difficult problems of permanent magnet demagnetization and excitation adjustment; on the rotor structure, one or more magnetic isolation layers are added along the direction of the q-axis magnetic circuit, which is conducive to further improving the reliability and fault tolerance of the motor drive system.

Beneficial effect:

Compared with the prior art, the present invention has the following beneficial effects:

(1) The permanent magnets in the rotor are arranged in a "V" shape. The permanent magnets have both radial magnetization and tangential magnetization, which effectively concentrates the magnetic flux and improves the output of the motor. At the same time, it has a wide speed range and high power density. and high efficiency advantages;

(2) Add one or more magnetic isolation layers along the q-axis magnetic circuit direction in the rotor to increase the effective air gap along the q-axis direction, reduce the q-axis inductance, and increase the difference between the d-axis inductance and the q-axis inductance , which is beneficial to solve the problem of zero-low speed operation in position sensorless control, further improves the reliability and fault tolerance of the motor drive system, and is also conducive to further improving the torque output of the motor

(3) Redundant electric excitation is adopted. When the permanent magnet has a demagnetization or demagnetization fault, the excitation magnetic field generated by the electric excitation winding can be used to maintain the operation of the motor and improve the fault tolerance of the motor;

(4) The armature winding on the stator is a centralized winding with short ends for easy installation, and the fault-tolerant teeth without windings serve as a magnetic flux circuit, and at the same time realize the isolation of the circuit, magnetic circuit and temperature field between phases of the motor , improving the reliability and fault-tolerant operation capability of the motor;

(5) From the perspective of motor design, comprehensively consider the fault tolerance of the motor and its control system, including motor demagnetization or demagnetization faults, phase-to-phase short-circuit or open-circuit faults, phase winding faults, and mechanical sensor faults in the motor control system. High reliability and strong fault-tolerant operation performance.

Description of drawings

Fig. 1 is a structural schematic diagram of the motor of the present invention.

Among them: 1 stator, 2 rotor, 3 permanent magnet, 4 armature tooth, 5 fault-tolerant tooth, 6 armature coil, 7 excitation coil, 8 magnetic isolation layer.

detailed description

The present invention will be further described below in conjunction with the accompanying drawings.

As shown in Figure 1, a hybrid excitation fault-tolerant motor based on position self-detection is specifically a three-phase 12-slot/10-pole motor, including a stator 1, a rotor 2, a permanent magnet 3, an armature tooth 4, and a fault-tolerant tooth 5 , Armature coil 6, excitation coil 7 and magnetic isolation layer 8. The armature teeth 4 and the fault-tolerant teeth 5 are evenly distributed along the inner ring of the stator 1, the total number of teeth is a multiple of 2m (m is the number of phases of the motor), and the tooth width of the armature teeth 4 and the tooth width of the fault-tolerant teeth 5 are different. equal. The permanent magnet 3 is embedded in the rotor 2. The permanent magnet 3 is composed of two magnetic strips that are radially symmetrical along the rotor at one end close to the rotor axis. The shape is "V", so that the permanent magnet has both radial magnetization and There is also tangential magnetization, which effectively concentrates the magnetic flux, improves the torque of the motor, and can effectively expand the speed range of the motor. The difference between the total number of teeth of the armature teeth 4 and the fault-tolerant teeth 5 and the number of pole pairs of the permanent magnet 3 is ±2.

The armature teeth 4 are wound with armature coils 6, which are single-layer concentrated windings, and two adjacent single-layer concentrated windings are isolated by fault-tolerant teeth 5, which provide magnetic flux circuits and at the same time achieve magnetic isolation between phases and physical The function of isolation, thermal isolation and electrical isolation has high reliability and ability to operate with faults, and reduces torque ripple. In addition, the armature coil 601 and the armature coil 604 are connected in series as the A-phase winding, the armature coil 602 and the armature coil 605 are connected in series as the B-phase winding, and the armature coil 603 and the armature coil 606 are connected in series as the C-phase winding, so that the present invention Fundamentally avoid phase-to-phase short circuit.

The exciting coil 7 is set on the fault-tolerant tooth 5, and there are 6 in total, including the exciting coil 701, the exciting coil 702, the exciting coil 703, the exciting coil 704, the exciting coil 705 and the exciting coil 706, and these 6 exciting coils are sequentially connected end to end to form a Set of single-phase concentrated excitation winding, when the permanent magnet 3 has demagnetization or demagnetization failure, the excitation magnetic field generated by the electric excitation winding 7 can be used to maintain the operation of the motor and improve the fault tolerance of the motor.

One or more slots are opened between a pair of permanent magnet poles in the rotor 2 along the q-axis magnetic circuit direction to form one or more magnetic isolation layers 8 to increase the effective air gap along the q-axis direction and reduce the q-axis Inductance, increasing the difference between the d-axis inductance and the q-axis inductance is conducive to solving the problem of zero-low speed operation in the position sensorless control, further improving the reliability and fault tolerance of the motor drive system, and is also conducive to further improving the rotation speed of the motor. torque output.

The working principle of the present invention is as follows: the motor generates the main magnetic field jointly by two kinds of excitation sources, permanent magnet excitation and electric excitation. Potential source. When the motor is working normally, the electric excitation magnetic potential mainly plays the role of increasing or weakening the magnetic flux of the main magnetic circuit, so as to realize the adjustable air gap magnetic field of the motor; due to the large difference between the d-axis inductance and the q-axis inductance, the torque of the motor can be further improved At the same time, the motor drive system adopts position sensorless control, which avoids the failure of mechanical sensors in the drive system and improves the reliability of the drive system; The maximum excitation current generates an excitation magnetic field, which interacts with the armature winding to generate sufficient torque to meet the system operation requirements.

The above is only a preferred embodiment of the present invention, it should be pointed out that, for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications can also be made. It should be regarded as the protection scope of the present invention.

Claims (5)

1. a composite excitation fault-tolerant motor system based on position automatic detection, including stator (1), rotor (2), permanent magnet (3), Armature tooth (4), fault-tolerant teeth (5), armature coil (6) and magnet exciting coil (7)；Armature tooth (4) and fault-tolerant teeth (5) are along stator inner ring Circumferentially-spaced it is uniformly distributed, and the facewidth of the facewidth of armature tooth (4) and fault-tolerant teeth (5) is unequal；Armature tooth is wound with electricity on (4) Pivot coil (6), for monolayer concentratred winding, is isolated, diametrically by fault-tolerant teeth (5) between two adjacent monolayer concentratred winding Two armature tooths (4) on armature coil (6) be connected into a phase；Magnet exciting coil (7) is sleeved on stator fault-tolerant teeth (5), and encourages Magnetic coil (7) head and the tail successively are composed in series a set of single-phase central excitation winding；Rotor (2) is embedded in permanent magnet (3)；All permanent magnetism Body (3) constitutes permanent magnetic field, and all magnet exciting coils (7) constitute electricity excitation magnetic field；It is characterized in that: described permanent magnet (3) is by edge Two magnetic stripes of rotor radial symmetry are put together in the one end near described rotor axis；In described rotor (2), a pair forever Open one or more notch along q axle magnetic circuit direction between magnetic pole, formed one or more every magnetosphere (8).

A kind of composite excitation fault-tolerant motor system based on position automatic detection the most according to claim 1, it is characterised in that: Total number of teeth of armature tooth (4) and fault-tolerant teeth (5) is the multiple of 2m, and armature tooth (4) and total number of teeth of fault-tolerant teeth (5) and permanent magnetism The difference of the number of pole-pairs of body (3) is ± 2, and wherein m is the number of phases of motor.

A kind of composite excitation fault-tolerant motor system based on position automatic detection the most according to claim 1, it is characterised in that: Described stator (1) and rotor (2) iron core are stalloy, ferrum, cobalt or nickel.

A kind of composite excitation fault-tolerant motor system based on position automatic detection the most according to claim 1, it is characterised in that: Described permanent magnet (3) is neodymium iron boron, Rare-Earth Cobalt or aluminum nickel cobalt.

A kind of composite excitation fault-tolerant motor system based on position automatic detection the most according to claim 1, it is characterised in that: Described in magnetosphere (8), it is provided with aluminum or copper.