1. A mesostructured material comprising a mineral phase within which are dispersed particles of nanometric dimensions comprising at least one metal oxide in the crystalline state selected from a cerium oxide, a zirconium oxide, a titanium oxide and an oxide of a rare earth other than cerium, said oxide comprising at least one metallic element M in the cationic form, in solid solution within the crystalline lattice of said oxide.
2. A material according to claim 1, which is thermally stable.
3. A material according to claim 1, wherein at least at a local level, it has one or more mesostructures selected from mesoporous mesostructures with three-dimensional hexagonal P63mmc symmetry, with two-dimensional hexagonal symmetry, with three-dimensional cubic Ia3d, Im3m or Pn3m symmetry; from vesicular or lamellar type mesostructures, or from vermicular type mesostructures.
4. A material according to claim 1, wherein said particles with nanometric dimensions are particles with a spherical or isotropic morphology at least 50% of the population of which has a mean diameter in the range 1 to 10 nm, or highly anisotropic rod type particles at least 50% of the population of which has a mean transverse diameter in the range 1 to 10 nm and a mean length that does not exceed 100 nm.
5. A material according to claim 1, wherein the metal oxide present within said particles with nanometric dimensions has a degree of crystallinity of 30% to 100% by volume.
6. A material according to claim 1, wherein the quantity of cations of element M in solid solution (or, if appropriate, of the totality of the solid solution doping agents) represents at least 0.2% of the total quantity of metallic cations present in the oxide.
7. A material according to claim 1, wherein said particles with nanometric dimensions are particles based on cerium oxide, and in that said element M is selected from rare earths other than cerium, transition metals that are capable of being integrated in the cationic form in solid solution into a cerium oxide, and alkaline-earth metals.
8. A material according to claim 1, wherein said particles with nanometric dimensions are particles based on zirconium oxide, and in that said element M is selected from rare earths, transition metals that are capable of being integrated in the cationic form in solid solution into a zirconium oxide, and alkaline-earth metals.
9. A material according to claim 1, wherein said particles with nanometric dimensions are particles based on titanium oxide, and said element M is selected from rare earths, transition metals that are capable of being integrated in the cationic form in solid solution into a titanium oxide, and alkaline-earth metals.
10. A material according to claim 1, wherein said particles with nanometric dimensions are particles based on an oxide of a rare earth other than cerium, and said element M is selected from rare earths other than the rare earth constituting said oxide, transition metals that are capable of being integrated in the cationic form in solid solution into a rare earth oxide, and alkaline-earth metals.
11. A material according to claim 1, wherein said mineral phase is at least partially constituted by silica.
12. A material according to claim 1, wherein the mineral phase also comprises metallic cations of metal M ador clusters based on metal M dispersed within said mineral phase andor on the surface of said mineral phase.
13. A material according to claim 1, wherein at least a portion of the particles with nanometric dimensions dispersed within the mineral binder phase is in contact with porous portions constituting the internal space of the material.
14. A material according to claim 1, wherein the (mineral binder phaseparticles with nanometric dimensions) molar ratio is in the range 20:80 to 99.5:0.5.
15. A material according to claim 1, which comprises crystallites based on the oxide, hydroxide, oxyhydroxide, carbonate or hydroxycarbonate of said element M.
16. An ordered mesoporous or mesostructured material according to claim 1, wherein said material has a BET specific surface area in the range 750 to 2300 m2 per cm3 of material.
17. A process for preparing a material according to claim 1, which comprises successive steps comprising:
a) producing a mineral mesostructure integrating, within its walls, particles with nanometric dimensions comprising a metal oxide in its crystalline state selected from a cerium oxide, a zirconium oxide, a titanium oxide and a rare earth oxide other than cerium;
b) introducing into the mesoporous structure obtained, a compound based on said element M, the total amount of element M introduced into the structure with respect to the total surface area developed by the mesostructure being less than 5 micromoles of cation per m2 of surface; and
c) subjecting the mesostructure produced to a temperature of at least 300\xb0 C. and not higher than 1000\xb0 C.
18. A preparation process according to claim 17, which step a) is implemented by carrying out the following steps:
a1) forming an initial medium comprising a templating agent, namely a surfactant type amphiphilic compound which can form micelles in the reaction medium;
a2) adding to the medium of step 1a) a colloidal dispersion of particles with nanometric dimensions based on a metal oxide in the crystalline state, selected from cerium oxide, a zirconium oxide, a titanium oxide and a rare earth oxide other than cerium;
a3) forming a mesostructured mineral phase, usually at least partially, or even essentially constituted by silica, said mineral phase by adding a mineral precursor to the medium; and
a4) eliminating the templating agent, in particular by heat treatment or by entrainment by a solvent.
19. A preparation process according to claim 17, wherien step b) is carried out by immersing the mesostructured material obtained at the end of step a) in a solution comprising the element M in a concentration in the range 0.1 to 1.5 mol1 then filtering the medium obtained.
20. A preparation process according to claim 17, wherein step b) is carried out by immersing the mesostructured material obtained at the end of step a) in an aqueous or hydro-alcoholic solution comprising cations of metal M in a concentration in the range 0.2 to 1.5 mol1 then centrifuging the medium obtained at a rate of 2000 to 5000 rpm, for a period not exceeding 30 minutes.
21. A preparation process according to claim 17, wherein, following the impregnationheat treatment procedures of steps b) and c), it comprises one or more subsequent impregnationheat treatment cycles implementing steps of type b) and c) carried out on the solid obtained from the preceding cycle.
22. A material that can be obtained by the process of claim 17, which is a heterogeneous acidic, basic or redox catalyst.
23. A material comprising particles of cerium oxide integrating manganese in solid solution within the walls of its mesostructure, as a catalyst for absorption of oxides of nitrogen.
24. A material obtained by a process according claim 1, as a support for catalytic species.
25. A catalyst obtained by supporting catalytic species on a material according to claim 1.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method for operation of an internal permanent magnet motor having a rotor, the method comprising:
determining whether a neutral point access signal is received from the rotor;
operating the internal permanent magnet motor using sensorless signals corresponding to a rotor position and a rotor speed of the rotor derived by a first sensorless signal estimation method when the neutral point access signal is received from the rotor; and
operating the internal permanent magnet motor using sensorless signals corresponding to a rotor position and a rotor speed of the rotor derived by a second sensorless signal estimation method when the neutral point access signal is not received from the rotor,
wherein the first sensorless signal estimation method utilizes the neutral point access signal to generate the rotor position and the rotor speed, and
wherein the second sensorless signal estimation method does not utilize the neutral point access signal to generate the rotor position and the rotor speed.
2. The method in accordance with claim 1 wherein operating the internal permanent magnet motor using sensorless signals corresponding to a rotor position and a rotor speed of the rotor derived by the first sensorless signal estimation method comprises operating the internal permanent magnet motor using sensorless signals corresponding to a rotor position and a rotor speed of the rotor derived by a pulse width modulated signal modification method.
3. The method in accordance with claim 2 wherein operating the internal permanent magnet motor using sensorless signals corresponding to a rotor position and a rotor speed of the rotor derived by the pulse width modulated signal modification method comprises operating the internal permanent magnet motor at speeds of the permanent magnet motor lees than a predetermined low speed threshold using sensorless signals corresponding to a rotor position and a rotor speed of the rotor derived by the pulse width modulated signal modification method in response to the neutral point access signal.
4. The method in accordance with claim 3 wherein operating the internal permanent magnet motor using sensorless signals corresponding to a rotor position and a rotor speed of the rotor derived by a second sensorless signal estimation method comprises:
injecting a high frequency signal into a flux axis of the permanent magnet motor; and
sensorlessly determining the rotor position and the rotor speed in response to both a flux axis error signal on a flux axis of the permanent magnet motor and a torque axis error signal on the torque axis of the permanent magnet motor, both the flux axis error signal and the torque axis error signal determined in response to current vector signals in a synchronous reference frame.
5. The method in accordance with claim 4 wherein injecting the high frequency signal into the flux axis of the permanent magnet motor comprises injecting a high frequency low speed injection signal into the flux axis of the permanent magnet motor at speeds of the permanent magnet motor less than a predetermined low speed threshold.
6. The method in accordance with claim 1 wherein operating the internal permanent magnet motor using sensorless signals corresponding to a rotor position and a rotor speed of the rotor derived by a second sensorless signal estimation method comprises operating the internal permanent magnet motor using sensorless signals corresponding to a rotor position and a rotor speed of the rotor derived by a sensorless high frequency signal injection method.
7. The method in accordance with claim 6 wherein operating the internal permanent magnet motor using sensorless signals corresponding to a rotor position and a rotor speed of the rotor derived by a sensorless high frequency signal injection method comprises:
injecting a high frequency signal into a flux axis of the permanent magnet motor; and
sensorlessly determining the rotor position and the rotor speed in response to both a flux axis error signal on a flux axis of the permanent magnet motor and a torque axis error signal on the torque axis of the permanent magnet motor, both the flux axis error signal and the torque axis error signal determined in response to current vector signals in a synchronous reference frame.
8. The method in accordance with claim 7 wherein injecting the high frequency signal into the flux axis of the permanent magnet motor comprises injecting a high frequency low speed injection signal into the flux axis of the permanent magnet motor at speeds of the permanent magnet motor less than a predetermined low speed threshold.
9. A limp home controller for controlling operation of an internal permanent magnet motor having a rotor, the limp home controller comprising:
a first sensorless speed and position estimator for generating sensorless rotor position and rotor speed signals in accordance with a first sensorless signal estimation method, wherein the first sensorless signal estimation method utilizes a neutral point access signal received from the rotor to generate the sensorless rotor position and rotor speed signals; a second sensorless speed and position estimator for generating sensorless rotor position and rotor speed signals in accordance with a second sensorless signal estimation method, wherein the second sensorless signal estimation method does not utilize the neutral point access signal to generate the sensorless rotor position and rotor speed signals; and
a supervisory controller coupled to the first sensorless speed and position estimator and the second sensorless speed and position estimator, the supervisory controller determining whether the neutral point access signal is received from the rotor and providing the sensorless rotor position and rotor speed signals from the first sensorless speed and position estimator for controlling the operation of the internal permanent magnet motor when the neutral point access signal is received from the rotor and providing the sensorless rotor position and rotor speed signals from the second sensorless speed and position estimator for controlling the operation of the internal permanent magnet motor when the neutral point access signal is not received from the rotor.
10. The limp home controller in accordance with claim 9 wherein the first sensorless speed and position estimator comprises a zero sequence voltage calculator coupled to the permanent magnet motor for receiving the neutral point access signal therefrom and generating a zero sequence voltage signal in response to the neutral point access signal, the first sensorless speed and position estimator generating the sensorless rotor position and rotor speed signals in response to the zero sequence voltage signal.
11. The limp home controller in accordance with claim 10 wherein the first sensorless speed and position estimator derives the sensorless rotor position and rotor speed signals by a pulse width modulated signal modification method in response to the zero sequence voltage signal.
12. The limp home operation controller in accordance with claim 9 wherein the supervisory controller comprises a neutral point access signal detector which determines whether the neutral point access signal is received from the rotor.
13. The limp home operation controller in accordance with claim 12 wherein the supervisory controller further comprises a selector coupled to the first and second sensorless speed and position estimators and the neutral point access signal detector, the selector providing the sensorless rotor position and rotor speed signals from the first sensorless speed and position estimator for controlling the operation of the internal permanent magnet motor when the neutral point access signal detector determines that the neutral point access signal is received from the rotor and for providing the sensorless rotor position and rotor speed signals from the second sensorless speed and position estimator for controlling the operation of the internal permanent magnet motor when the neutral point access signal detector determines that the neutral point access signal is not received from the rotor.
14. The limp home operation controller in accordance with claim 9 wherein the second sensorless speed and position estimator derives the sensorless rotor position and rotor speed signals by a sensorless high frequency signal injection method.
15. An electric motor system comprising:
an internal permanent magnet motor comprising a plurality of phases and including a rotor;
an inverter for generating a plurality of phase signals in response to modulated control signals and coupled to the internal permanent magnet motor for providing each of the plurality of phase signals to a corresponding one of the plurality of phases of the permanent magnet motor;
an inverter controller for generating the modulated control signals in response to a rotor position signal, a rotor speed signal and phase current signals, the phase current signals corresponding to currents of one or more of the plurality of phase signals; and
a limp home controller coupled to the internal permanent magnet motor and the inverter controller for determining whether a neutral point access signal is received from the rotor and providing sensorless rotor position and rotor speed signals to the inverter controller as the rotor position signal and the rotor speed signal, wherein the sensorless rotor position and rotor speed signals are derived by a first sensorless signal estimation method utilizing the neutral point access signal when the neutral point access signal is received from the rotor, the limp home controller further providing sensorless rotor position and rotor speed signals derived by a second sensorless signal estimation method to the inverter controller as the rotor position signal and the rotor speed signal when the neutral point access signal is not received from the rotor.
16. The electric motor system in accordance with claim 15 wherein the limp home controller comprises:
a first sensorless speed and position estimator for generating the sensorless rotor position and rotor speed signals in accordance with the first sensorless signal estimation method;
a second sensorless speed and position estimator for generating the sensorless rotor position and rotor speed signals in accordance with the second sensorless signal estimation method, wherein the second sensorless signal estimation method does not utilize the neutral point access signal to generate the sensorless rotor position and rotor speed signals; and
a supervisory controller coupled to the first sensorless speed and position estimator and the second sensorless speed and position estimator, the supervisory controller determining whether the neutral point access signal is received from the rotor and providing the sensorless rotor position and the rotor speed signals from the first sensorless speed and position estimator as a rotor position signal and a rotor speed signal to the inverter controller when the neutral point access signal is received from the rotor and providing the sensorless rotor position and rotor speed signals from the second sensorless speed and position estimator as the rotor position signal and the rotor speed signal to the inverter controller when the neutral point access signal is not received from the rotor.
17. The electric motor system in accordance with claim 16 wherein the first sensorless speed and position estimator comprises a zero sequence voltage calculator coupled to the internal permanent magnet motor for receiving the neutral point access signal therefrom and generating a zero sequence voltage signal in response to the neutral point access signal, the first sensorless speed and position estimator generating the sensorless rotor position and rotor speed signals by a pulse width modulated signal modification method in response to the zero sequence voltage signal.
18. The electric motor system in accordance with claim 16 wherein the supervisory controller comprises a neutral point access signal detector which determines whether the neutral point access signal is received from the rotor.
19. The electric motor system in accordance with claim 18 wherein the supervisory controller further comprises a selector coupled to the first and second sensorless speed and position estimators and the neutral point access signal detector, the selector providing the sensorless rotor position and rotor speed signals from the first sensorless speed and position estimator as the rotor position signal and the rotor speed signal to the inverter controller when the neutral point access signal detector determines that the neutral point access signal is received from the rotor and for providing the sensorless rotor position and rotor speed signals from the second sensorless speed and position estimator as the rotor position signal and the rotor speed signal to the inverter controller when the neutral point access signal detector determines that the neutral point access signal is not received from the rotor.
20. The electric motor system in accordance with claim 16 wherein the second sensorless speed and position estimator derives the sensorless rotor position and rotor speed signals by a sensorless high frequency signal injection method.