Reversing differential driven magnetic bearing
Technical Field Field the present invention relates to a bearing, in particular to a kind of reverse differential driving of the reverse magnetic bearing and differential driving means for the magnetic bearing. Background technology Magnetic bearing is the rotor by electromagnetic force suspended in the space, between the rotor and the stator without contact support a novel high-performance bearing. Compared with the ordinary bearing magnetic bearing, a magnetic bearing is mainly composed of a high-speed, non-contact, non-lubrication, can control the position of the rotor, and the like. The control system is a magnetic bearing system is very important in a ring, the quality of the control system has a direct impact on the performance of the system as a whole, includes a stability, dynamic stiffness, such as anti-interference capability. In a conventional magnetic bearing in the application system, magnetic bearing generally adopts the differential excitation drive. The so-called differential excitation driving is magnetic bearing in a constrained degree of freedom of the two direction opposite to the direction of force of the magnet to work at the same time. Such arrangement enables the magnetic bearing in the-degree-of-freedom direction not only can generate positive force on, and can produce the reverse force. Conventional differential drive control of the magnetic bearing, its working principle is:as shown in Figure 1 is shown in the affected by the external force of the rotor magnetic bearing and, to deviate from the equilibrium position to the mobile-y shaft, a magnetic bearing of the magnet in order to bias the current i0 the control current iy and (i0 +iy) excitation, the magnetic bearing of a magnet in order to bias the current i0 the control current iy difference (i0-iy) excitation. Y-axis direction magnetic bearing the electromagnetic force change Shangdi overcome by the external force of the magnetic suspension of the rotor, its back to the equilibrium position. In the conventional magnetic bearing electromagnet of the stator has the characteristics of the inductive load, under the same excitation conditions, inductance, the greater the larger the electromagnetic force thereof, however, the inductance, the greater the smaller the rate of change of the electromagnetic force. The magnetic bearing of the magnetic bearing requirements for working conditions are not only both large electromagnetic force, and the electromagnetic force of the fast rate of change. Conventional differential drive control of the magnetic bearing, which is composed of a stator, a rotor, a sensor, controller, power amplifier. The main defects that: changes in the electromagnetic force of the magnetic bearing is relatively slow, poor dynamic characteristics of the magnetic bearing. The content of the invention The invention the technical problem to be solved is: against conventional differential drive control of the magnetic force of the defects of the bearing, provides a reverse differential driven magnetic bearing, in a better meet the working conditions of the magnetic bearing drive control method, the dynamic characteristics of the improved magnetic bearing. To solve the technical problems of the present invention adopts the following technical scheme: The present invention provides the following two kinds of reverse differential drive control magnetic bearing: 1st reverse differential drive control of the magnetic bearing, comprising a stator, a rotor, a sensor, controller, power amplifier. In the magnetic bearing of the two-degree-of-freedom direction relative to the position in of the electromagnet, are respectively wound with a group of large number of turns of coil and a series of small number of turns of the coil, with a large number of turns of the electromagnet coil and the small number of turns of the coil wound in the opposite directions; a large number of turns of the electromagnet coil is respectively connected with the opposite direction of the small number of turns on coil in series, and with the same power amplifier drive; two opposite electromagnets is equal and in opposite direction to the control current excitation. 2nd reverse differential drive control of the magnetic bearing, comprising a stator, a rotor, a sensor, controller, power amplifier. In the magnetic bearing of the two-degree-of-freedom direction relative to the position in of the electromagnet, are respectively wound with a group of large number of turns of coil and a series of small number of turns of the coil, with a large number of turns of the electromagnet coil and the small number of turns of the coil wound in the opposite directions; two opposite large number of turns of the coil of the electromagnet is driven by two power amplifiers respectively, two opposite small number of turns of the coil of the electromagnet is driven by two power amplifiers respectively; two opposite large number of turns of the electromagnet coil to equal size excited by the control current in the opposite direction, two opposite small number of turns of the coil of the electromagnet with the large number of turns of the coil to control the current direction on the contrary, the control current excitation arbitrary size. The invention and the conventional differential driving compared with the magnetic bearing, the remarkable effect of the following are the main: reverse differential driven magnetic bearing when in operation, electromagnetic force can be more rapid changes, the dynamic characteristics of the magnetic bearing. Reverse differential driven magnetic bearing in the overshoot, adjusting time, the steady state error and the like is superior to the conventional differential driving magnetic bearing. Figure description Figure 1 is schematic diagram the magnetic bearing of the conventional differential drive control. Figure 2 is a magnetic bearing schematic diagram of single power amplifier reverse differential drive control. Figure 3 is schematic diagram of magnetic bearing of the double-power amplifier reverse differential drive control. Specific embodiments The invention provides a completely novel for the active magnetic bearing of the reverse differential driving mode. Which is mainly characterized in that: 1. The stator is made up of a plurality of pairs of electromagnetic iron, the most common are two pairs, in each electromagnetic iron increases the reverse differential coil; 2. The reverse differential control method to drive the magnetic bearing; 3. With reverse differential the magnetic force of the coil bearing, not only can the single power amplifier can also be double-power amplifier to drive the. The present invention provides the following two kinds of reverse differential drive control of the magnetic bearing. 1st a single power amplifier reverse differential drive control of the magnetic bearing, which comprises a stator, the rotor 5, sensor 6, controller and a power amplifier 1. In the magnetic bearing of the two-degree-of-freedom direction relative to the position of the electromagnet 2 in, are respectively wound with a group of large number of turns of the coil 3 and a group of small number of turns of the coil 4, two groups of coils wound in the opposite directions. Wherein: as shown in Figure 2, each electromagnet large turn windings of the electromagnet are respectively connected with the opposite direction of the small number of turns of the coil are connected in series, each series circuit with a power amplifier driving; two opposite electromagnets is equal and in opposite direction to the control current excitation. 2nd double-power amplifier the reverse differential drive control of the magnetic bearing, which comprises a stator, the rotor 5, sensor 6, controller and a power amplifier 1. In the magnetic bearing of the two-degree-of-freedom direction relative to the position of the electromagnet 2 in, are respectively wound with a group of large number of turns of the coil 3 and a group of small number of turns of the coil 4, two groups of coils wound in the opposite directions. Wherein: as shown in Figure 3, the large number of turns in the coil and the small turn coil driven by two power amplifiers respectively, two opposite large number of turns of the coil of the electromagnet is still equal and in opposite direction of the large and small control current excitation, and two opposite small number of turns of the coil of the electromagnet with the large number of turns of the coil to control the current direction on the contrary, the control current excitation arbitrary size. In the above-mentioned two kinds of reverse differential drive control of the magnetic bearing, the small coil and the large coil of the turns ratio of the 1 [...] the 1-1 [...] 6, or according to the actual circumstances. The large coil and small coil material can adopt the copper wire. Copper wire acetal paint round copper wire can be adopted. Two kinds of above-mentioned reverse differential drive control of the magnetic bearing, the control principle and a difference on the hardware. Single power amplifier reverse differential drive control of the magnetic bearing, as shown in Figure 2 its principle of control: is suspended rotor 5 simplified as a particle, in the magnetic bearing y axial direction of two opposite directions in the upper electro-magnet, are respectively wound with a group of large coil L and a group of small coil l, two groups of coils wound in the opposite directions; each of the large coil of the electromagnet relative to the direction of the series of small coil of the electromagnet, this series circuit with a power amplifier driving, in order to have equal size, excited by the control current in the opposite direction, carrying out differential drive control. Affected by the external force when the magnetic suspension of the rotor, to deviate from the equilibrium position the negative direction y shaft displacement, in the magnetic bearing of a large coil of the electromagnet in order to bias current i0 the control current iy and (i0 +iy) excitation, at the same time in the opposite direction of the large coil of the electromagnet in order to bias current i0 the control current iy difference (i0-iy) excitation. Affected by the external force when the magnetic suspension of the rotor, to deviate from the equilibrium position when the displacement of the axes of the other direction, the same principle of controlling the same. Single power amplifier reverse differential drive control of the magnetic bearing, its because of the relative direction in series in the reverse direction, of the coil on the electromagnet, the presence of a magnet at the same time in two upper and lower exciting current the generated magnetic field. The same direction as the electromagnetic field, the electromagnetic force of the magnets so as to increase more quickly. In the magnet and below one of the circumstances of and the contrary, the underlying electromagnetic force of the magnet is reduced more quickly. Its comprehensive the result is that the magnetic bearing y the electromagnetic force of the shaft in the direction change more rapidly, the dynamic characteristics of the magnetic bearing. Double power amplifier reverse differential drive control of the magnetic bearing, as shown in Figure 3 the control principle schematic diagram: the suspended rotor 5 simplified as a particle, in the magnetic bearing y axial direction of two opposite directions in the upper electro-magnet, are respectively wound with a group of large coil L and a group of small coil l, two groups of coils wound in the opposite directions; and each large coil of the electromagnet L and small coil l broken open, of the electromagnet, of small coil driven by two power amplifiers respectively, two opposite large number of turns of the coil of the electromagnet is still equal and in opposite direction of the large and small control current excitation, and the small number of turns of the large number of turns of the coil are respectively opposite to the direction of current in coil, excited by the control current of arbitrary size. Affected by the external force when the magnetic suspension of the rotor, to deviate from the equilibrium position the negative direction y shaft displacement, in the magnetic bearing electromagnet in a large coil in order to bias the current i0 the control current iy and (i0 +iy) excitation, the small coil of the electromagnet at the same time in order to control the current k2iy excitation. At the same time, the large coil of the electromagnet in order to bias the current i0 the control current iy difference (i0-iy) excitation, the small coil of the electromagnet in order to control the current-k1iy excitation. That is, the two opposite electromagnets to still large turn windings of the large and small equal and in opposite direction of the control current excitation, and the small number of turns of the large number of turns of the coil of the coil to control the current direction on the contrary, the control current excitation arbitrary size; affected by the external force when the magnetic suspension of the rotor, to deviate from the equilibrium position when the displacement of the axes of the other direction, the same principle of controlling the same. Double power amplifier reverse differential drive control of the magnetic bearing, the electromagnet because of the large, small coil wound in the opposite directions, a magnet at the same time the presence of large, small coil two excitation current the generated magnetic field, the direction of the electromagnetic field are the same, so that the electromagnetic force of the magnet is increased more quickly. In the magnet and below one of the circumstances of and the contrary, the underlying electromagnetic force of the magnet is reduced more quickly. Its comprehensive the result is that the magnetic bearing y the electromagnetic force of the shaft in the direction change more rapidly, the dynamic characteristics of the magnetic bearing. Double power amplifier reverse differential drive control of the magnetic bearing with a single power amplifier has the reverse differential drive control of the magnetic bearing to the characteristics of the similar, because small coil by the single power amplifier drive, therefore, can be more flexibly select reverse differential control current, obtain a single power amplifier reverse differential better control effect. The above-mentioned two kinds of reverse differential drive control of the magnetic bearing, is in common the same winding way of the two bearings, large coil and the small number of turns of the coil, large coil and small coil turns than are the same. The difference lies in the double-power amplifier reverse differential drive control of the magnetic force of each electromagnet of the large coil and small coil is broken, the electromagnet is large, small coil driven by two power amplifiers respectively. It is precisely because of the electro-magnet the coil is not in the opposite direction is connected with the small coil of the electromagnet, then large, small coil can be in different current excitation. single power amplifier and reverse differential drive control of the magnetic force of each electromagnet of the bearing in the direction of the large coil of the upper electro-magnet with a relatively small coil are connected in series, in the series loop of large, the small coil current excitation in the same. The present invention provides magnetic bearing, its preparation method and the conventional magnetic bearing similar to the preparation method, the difference is that magnetic bearing stator at the time of processing, conventional differential driving of the bearing stator of the magnetic force of each electromagnet is wound only one coil, reverse differential driven bearing stator of the magnetic force of each electromagnet the winding in the two coils, i.e., increasing the reverse differential coil. The implementation of this invention, magnetic bearing design according to the set of basic knowledge of the structural size of the magnetic bearing, magnetic bearing stator is determined in the total turns of the electromagnetic coil. The stator of the magnetic bearing in the process of machining, in each of the stator winding of the electromagnet the reverse differential coil. The reverse differential electromagnet coil and small in the number of turns of the coil to the 1 [...] the 1-1 [...] 6. Large coil and small coil material can adopt the magnetic bearing commonly used copper wire, such as such as round copper wire acetal paint. The invention provides two magnetic bearings controlled by reverse differential driving. Each magnetic bearing comprises a stator, a rotor, a sensor, a controller and power amplifiers. A group of large turn windings and a group of small turn windings are wound on two opposite electromagnets in the freedom degree direction restrained by the magnetic bearings respectively, and the winding directions of the two groups of windings are opposite, wherein the large turn windings of the first magnetic bearing are connected in series with the small turn windings on the electromagnets in the opposite directions respectively, and driven by the same power amplifier. The two opposite electromagnets are excited by control current with equal intensity and opposite directions. The large turn windings andthe small turn windings of the second magnetic bearing are driven by two power amplifiers respectively, the large turn windings of the two opposite electromagnets are still excited by the control current with the equal intensity and the opposite directions, while the small turn windings are excited by the control current with directions opposite to the control current of the large turn windings and with random intensity respectively. Compared with the prior differential driven magnetic bearings, the two magnetic bearings have better dynamic characteristics. 1. A reverse differential driven magnetic bearing, comprising a stator, a rotor, a sensor, controller, power amplifier, which is characterized in that: the magnetic bearing of the two-degree-of-freedom direction relative to the position in of the electromagnet, are respectively wound with a group of large number of turns of coil and a series of small number of turns of the coil, with a large number of turns of the electromagnet coil and the small number of turns of the coil wound in the opposite directions; a large number of turns of the electromagnet coil is respectively connected with the opposite direction of the small number of turns on coil in series, and with the same power amplifier drive; in two opposite electromagnets to large turn windings of the large and small equal and in opposite direction of the control current excitation. 2. A reverse differential driven magnetic bearing, comprising a stator, a rotor, a sensor, controller, power amplifier, which is characterized in that: the magnetic bearing of the two-degree-of-freedom direction relative to the position in of the electromagnet, are respectively wound with a group of large number of turns of coil and a series of small number of turns of the coil, with a large number of turns of the electromagnet coil and the small number of turns of the coil wound in the opposite directions; two opposite large number of turns of the coil of the electromagnet is driven by two power amplifiers respectively, two opposite small number of turns of the coil of the electromagnet is driven by two power amplifiers respectively; two opposite large number of turns of the electromagnet coil to equal size excited by the control current in the opposite direction, two opposite small number of turns of the coil of the electromagnet with the large number of turns of the coil to control the current direction on the contrary, the control current excitation arbitrary size. 3. Reverse differential driven magnetic bearing as in Claim 1 or Claim 2, which is characterized in that: the small turn windings and a large number of turns than the number of turns of the coil 1 the [...] 6. 4. Reverse differential driven magnetic bearing according to Claim 3, which is characterized in that: a large number of turns of the coil and the small number of turns of copper wire material of the coil. 5. Reverse differential driven magnetic bearing according to Claim 4, which is characterized in that: the round copper wire acetal paint copper wire.