Six-phase PMSM control device based on double d-q axes and six-phase PMSM system
阅读说明:本技术 基于双d-q轴的六相PMSM控制装置及六相PMSM系统 (Six-phase PMSM control device based on double d-q axes and six-phase PMSM system ) 是由 王文洲 王云 任广辉 薛静 詹圣益 卢苗 殷桂来 于 2020-06-22 设计创作,主要内容包括:本申请提供了一种基于双d-q轴的六相PMSM控制装置及六相PMSM系统,包括第一控制电路通过电流检测电路采集六相电机输入端的六相电流,并将该六相电流依次进行clark变换、基于转子检测装置检测的六相电机中转子当前角度进行park变换和数据处理后,输出第一dq坐标系电压和第二dq坐标系电压。同时通过谐波抑制电路根据转子当前角度将clark变换后得到的第一坐标系电流和第二坐标系电流进行数据处理后,并输出第一坐标系电压和第二坐标系电压至第二控制电路,通过第二控制电路将二者分别进行ipark变换,并根据ipark变换后的第一坐标系电压和第二坐标系电压调整六相电机输入端的六相电流,从而可有效地抑制相电流不平衡现象和减少谐波,提高六相PMSM效率。(The application provides a six-phase PMSM control device and a six-phase PMSM system based on double d-q axes, and the six-phase PMSM control device and the six-phase PMSM system comprise a first control circuit, a current detection circuit, a clark conversion circuit, a rotor detection device and a data processing circuit, wherein the first control circuit collects six-phase current at the input end of a six-phase motor, the six-phase current is sequentially subjected to clark conversion, and after the park conversion and the data processing are performed on the current angle of a rotor in the six-phase motor detected by the rotor detection device, first dq coordinate system voltage and second dq coordinate system voltage are output. And meanwhile, after data processing is carried out on the first coordinate system current and the second coordinate system current obtained after the clark conversion through the harmonic suppression circuit according to the current angle of the rotor, the first coordinate system voltage and the second coordinate system voltage are output to the second control circuit, ipark conversion is respectively carried out on the first coordinate system current and the second coordinate system current through the second control circuit, and the six-phase current at the input end of the six-phase motor is adjusted according to the first coordinate system voltage and the second coordinate system voltage after the ipark conversion, so that the phase current imbalance phenomenon can be effectively suppressed, the harmonic wave can be reduced, and the six-phase PMSM efficiency can be improved.)
1. A dual d-q axis based six-phase PMSM control apparatus, comprising:
the current detection circuit (100) is used for collecting six-phase current at the input end of the six-phase motor (101);
the rotor detection device (200) is used for detecting the position of a rotor in the six-phase motor (101) and outputting the current angle of the rotor;
the first control circuit (300) is electrically connected with the current detection circuit (100) and the rotor detection device (200) respectively and is used for performing clark transformation on the six-phase current to obtain a first coordinate system current and a second coordinate system current, performing park transformation and data processing on the first coordinate system current based on the current angle of the rotor to output a first dq coordinate system voltage, and performing park transformation and data processing on the second coordinate system current based on the current angle of the rotor to output a second dq coordinate system voltage;
a harmonic suppression circuit (400) electrically connected to the current detection circuit (100), the rotor detection device (200), and the first control circuit (300), respectively, and configured to perform data processing on the first coordinate system current and the second coordinate system current according to a current angle of the rotor to obtain a first direct current and a second direct current, and output a first coordinate system voltage and a second coordinate system voltage based on the first direct current, the second direct current, the first dq coordinate system voltage, and the second dq coordinate system voltage; and
and the second control circuit (500) is electrically connected with the harmonic suppression circuit (400) and is used for respectively carrying out ipark transformation on the first coordinate system voltage and the second coordinate system voltage and adjusting the six-phase current at the input end of the six-phase motor (101) according to the first coordinate system voltage and the second coordinate system voltage after ipark transformation.
2. The dual d-q axis based six-phase PMSM control apparatus of claim 1, wherein the harmonic rejection circuit (400) comprises:
and the first processing unit (410) is electrically connected with the current detection circuit (100) and the rotor detection device (200) respectively, and is used for subtracting a first coordinate current in the first coordinate system current from a first coordinate current in the second coordinate system current to obtain a first component current, performing current conversion on the first component current according to the current angle of the rotor and outputting the first direct current, and is also used for subtracting a second coordinate current in the first coordinate system current from a second coordinate current in the second coordinate system current to obtain a second component current, and performing current conversion on the second component current according to the current angle of the rotor and outputting the second direct current.
3. The dual d-q axis based six-phase PMSM control apparatus of claim 2, wherein the harmonic rejection circuit (400) further comprises:
the self-adaptive control unit (420) is electrically connected with the first processing unit (410) and the rotor detection device (200) respectively, and is used for converting the first direct current into a first voltage according to the current angle of the rotor, performing data processing on the first voltage and a q-coordinate voltage in the first dq coordinate system voltage and a q-coordinate voltage in the second dq coordinate system voltage respectively, and outputting the first coordinate voltage in the first coordinate system voltage and the first coordinate voltage in the second coordinate system voltage; and the second direct current is converted into a second voltage according to the current angle of the rotor, the second voltage is subjected to data processing with a d-coordinate voltage in the first dq coordinate system voltage and a d-coordinate voltage in the second dq coordinate system voltage respectively, and the second coordinate voltage in the first coordinate system voltage and the second coordinate voltage in the second coordinate system voltage are output.
4. The dual d-q axis-based six-phase PMSM control apparatus of claim 1, wherein the first control circuit (300) comprises:
a current conversion unit (310) electrically connected to the current detection circuit (100) and the harmonic suppression circuit (400), respectively, for performing a clark conversion on the six-phase current and outputting the first coordinate system current and the second coordinate system current;
a first coordinate conversion unit (320) electrically connected to the current conversion unit (310) and the rotor detection device (200), respectively, for performing park conversion on the first coordinate system current according to the current angle of the rotor and outputting a first dq coordinate system current;
a second coordinate conversion unit (330), electrically connected to the current conversion unit (310) and the rotor detection device (200), respectively, for performing park conversion on the second coordinate system current according to the current angle of the rotor and outputting a second dq coordinate system current; and
and the processing unit (340) is electrically connected with the first coordinate conversion unit (320), the second coordinate conversion unit (330) and the harmonic suppression circuit (400) respectively, and is used for carrying out data processing on the first dq coordinate system current and outputting the first dq coordinate system voltage to the harmonic suppression circuit (400), and is also used for carrying out data processing on the second dq coordinate system current and outputting the second dq coordinate system voltage to the harmonic suppression circuit (400).
5. The dual d-q axis-based six-phase PMSM control apparatus of claim 4, wherein the processing unit (340) is configured to difference the first dq coordinate system current and a first preset coordinate system current to obtain a first difference coordinate system current, and convert the first difference coordinate system current and output the first dq coordinate system voltage to the harmonic suppression circuit (400);
the processing unit (340) is further configured to perform a difference between the second dq coordinate system current and a second preset coordinate system current to obtain a second difference coordinate system current, convert the second difference coordinate system current, and output a second dq coordinate system voltage to the harmonic suppression circuit (400).
6. The dual d-q axis based six-phase PMSM control apparatus of claim 1, wherein the second control circuit (500) comprises:
a third coordinate conversion unit (510) electrically connected to the harmonic suppression circuit (400) and configured to perform ipark conversion on the first coordinate system voltage and output a first coordinate system modulation voltage;
a fourth coordinate conversion unit (520) electrically connected to the harmonic suppression circuit (400) and configured to perform ipark conversion on the second coordinate system voltage and output a second coordinate system modulation voltage; and
and the SVPWM unit (530) is electrically connected with the third coordinate conversion unit (510) and the fourth coordinate conversion unit (520) respectively and is used for outputting a control signal according to the first coordinate system modulation voltage and the second coordinate system modulation voltage so as to adjust the six-phase current at the input end of the six-phase motor (101).
7. The dual d-q axis based six-phase PMSM control apparatus of claim 1, further comprising:
an inverter circuit (600), a first input terminal of the inverter circuit (600) is electrically connected with the second control circuit (500), a second input terminal of the inverter circuit (600) is used for being electrically connected with a power supply (601), an output terminal of the inverter circuit (600) is used for being connected with the current detection circuit (100) and the six-phase motor (101) in a common mode, and the second control circuit (500) adjusts the six-phase current at the input terminal of the six-phase motor (101) through the inverter circuit (600).
8. The dual d-q axis based six-phase PMSM control apparatus of claim 7, further comprising:
the input end of the filter circuit (700) is electrically connected with the output end of the inverter circuit (600), and the output end of the filter circuit (700) is electrically connected with the input end of the six-phase motor (101).
9. The dual d-q axis based six-phase PMSM control device according to any one of claims 1-8, wherein the current sensing circuit (100) is a resistive current sensor.
10. A six-phase PMSM system, comprising:
a six-phase motor (101); and
the dual d-q axis based six-phase PMSM control apparatus of any one of claims 1-8, for regulating the six-phase current at an input of the six-phase motor (101).
Technical Field
The application relates to the technical field of motors, in particular to a six-phase PMSM control device based on double d-q axes and a six-phase PMSM system.
Background
With the continuous development of motors and control technologies thereof, the multiphase variable frequency driving control technology is mature day by day, and in recent years, new energy technologies have attracted great interest. As a motor control device that converts renewable energy into mechanical energy, a motor controller has a wide application prospect, such as a new energy automobile drive system.
For controlling the current and torque of a dual-three-phase PMSM (permanent magnet synchronous motor), a conventional dual-d-q-axis six-phase PMSM control method is mostly adopted. However, the conventional dual d-q axis control method has difficulty in achieving effective suppression of harmonic components.
Disclosure of Invention
In view of the above, it is necessary to provide a six-phase PMSM control apparatus and a six-phase PMSM system based on dual d-q axes, in order to solve the problem that the conventional dual d-q axis control method is difficult to achieve effective suppression of harmonic components.
A dual d-q axis based six-phase PMSM control device comprising:
the current detection circuit is used for collecting six-phase current at the input end of the six-phase motor;
the rotor detection device is used for detecting the position of a rotor in the six-phase motor and outputting the current angle of the rotor;
the first control circuit is respectively electrically connected with the current detection circuit and the rotor detection device and is used for performing clark transformation on the six-phase current to obtain a first coordinate system current and a second coordinate system current, performing park transformation and data processing on the first coordinate system current based on the current angle of the rotor to output a first dq coordinate system voltage, and performing park transformation and data processing on the second coordinate system current based on the current angle of the rotor to output a second dq coordinate system voltage;
the harmonic suppression circuit is respectively electrically connected with the current detection circuit, the rotor detection device and the first control circuit, and is used for performing data processing on the first coordinate system current and the second coordinate system current according to the current angle of the rotor to obtain a first direct current and a second direct current, and outputting a first coordinate system voltage and a second coordinate system voltage based on the first direct current, the second direct current, the first dq coordinate system voltage and the second dq coordinate system voltage; and
and the second control circuit is electrically connected with the harmonic suppression circuit and used for respectively carrying out ipark transformation on the first coordinate system voltage and the second coordinate system voltage and adjusting the six-phase current at the input end of the six-phase motor according to the first coordinate system voltage and the second coordinate system voltage after ipark transformation.
In one embodiment, the harmonic rejection circuit includes:
and the first processing unit is respectively electrically connected with the current detection circuit and the rotor detection device, and is used for subtracting a first coordinate current in the first coordinate system current from a first coordinate current in the second coordinate system current to obtain a first component current, performing current conversion on the first component current according to the current angle of the rotor and outputting the first direct current, and is also used for subtracting a second coordinate current in the first coordinate system current from a second coordinate current in the second coordinate system current to obtain a second component current, and performing current conversion on the second component current according to the current angle of the rotor and outputting the second direct current.
In one embodiment, the harmonic rejection circuit further comprises:
the self-adaptive control unit is respectively electrically connected with the first processing unit and the rotor detection device, and is used for converting the first direct current into a first voltage according to the current angle of the rotor, performing data processing on the first voltage and a q-coordinate voltage in the first dq coordinate system voltage and a q-coordinate voltage in the second dq coordinate system voltage respectively, and outputting the first coordinate voltage in the first coordinate system voltage and the first coordinate voltage in the second coordinate system voltage; and the converter is further configured to convert the second direct current into a second voltage according to the current angle of the rotor, perform data processing on the second voltage and a d-coordinate voltage in the first dq coordinate system voltage and a d-coordinate voltage in the second dq coordinate system voltage respectively, and output the second coordinate voltage in the first coordinate system voltage and the second coordinate voltage in the second coordinate system voltage.
In one embodiment, the first control circuit comprises:
a current conversion unit, electrically connected to the current detection circuit and the harmonic suppression circuit, respectively, for performing clark conversion on the six-phase current and outputting the first coordinate system current and the second coordinate system current;
the first coordinate conversion unit is respectively electrically connected with the current conversion unit and the rotor detection device and is used for carrying out park conversion on the first coordinate system current according to the current angle of the rotor and outputting a first dq coordinate system current;
the second coordinate conversion unit is respectively electrically connected with the current conversion unit and the rotor detection device and is used for carrying out park conversion on the second coordinate system current according to the current angle of the rotor and outputting a second dq coordinate system current; and
and the processing unit is respectively electrically connected with the first coordinate conversion unit, the second coordinate conversion unit and the harmonic suppression circuit, and is used for carrying out data processing on the first dq coordinate system current and outputting the first dq coordinate system voltage to the harmonic suppression circuit, and is also used for carrying out data processing on the second dq coordinate system current and outputting the second dq coordinate system voltage to the harmonic suppression circuit.
In one embodiment, the processing unit is configured to obtain a first difference coordinate system current by subtracting the first dq coordinate system current from a first preset coordinate system current, convert the first difference coordinate system current, and output the first dq coordinate system voltage to the harmonic suppression circuit;
the processing unit is further configured to obtain a second difference coordinate system current by subtracting the second dq coordinate system current from a second preset coordinate system current, convert the second difference coordinate system current, and output a second dq coordinate system voltage to the harmonic suppression circuit.
In one embodiment, the second control circuit comprises:
the third coordinate conversion unit is electrically connected with the harmonic suppression circuit and used for carrying out ipark conversion on the first coordinate system voltage and outputting a first coordinate system modulation voltage;
the fourth coordinate conversion unit is electrically connected with the harmonic suppression circuit and used for carrying out ipark conversion on the second coordinate system voltage and outputting a second coordinate system modulation voltage; and
and the SVPWM unit is respectively and electrically connected with the third coordinate conversion unit and the fourth coordinate conversion unit and is used for outputting a control signal according to the first coordinate system modulation voltage and the second coordinate system modulation voltage so as to adjust the six-phase current at the input end of the six-phase motor.
In one embodiment, the dual d-q axis based six-phase PMSM control apparatus further comprises:
the first input end of the inverter circuit is electrically connected with the second control circuit, the second input end of the inverter circuit is electrically connected with a power supply, the output end of the inverter circuit is commonly connected with the current detection circuit and the six-phase motor, and the second control circuit adjusts the six-phase current at the input end of the six-phase motor through the inverter circuit.
In one embodiment, the dual d-q axis based six-phase PMSM control apparatus further comprises:
and the input end of the filter circuit is electrically connected with the output end of the inverter circuit, and the output end of the filter circuit is electrically connected with the input end of the six-phase motor.
In one embodiment, the current detection circuit is a resistive current sensor.
A six-phase PMSM system, comprising:
a six-phase motor; and
the dual d-q axis based six-phase PMSM control apparatus of any of the embodiments above, configured to regulate the six-phase current at the input of the six-phase motor.
Compared with the prior art, the six-phase PMSM control device and the six-phase PMSM system based on the double d-q axes have the advantages that the first control circuit collects six-phase current at the input end of the six-phase motor through the current detection circuit, sequentially performs clark transformation on the six-phase current, performs park transformation and data processing on the current angle of the rotor in the six-phase motor detected by the rotor detection device, and outputs first dq coordinate system voltage and second dq coordinate system voltage; and meanwhile, after data processing is carried out on the first coordinate system current and the second coordinate system current obtained after the clark conversion according to the current angle of the rotor through a harmonic suppression circuit, a first coordinate system voltage and a second coordinate system voltage are output to a second control circuit according to the first dq coordinate system voltage and the second dq coordinate system voltage, ipark conversion is respectively carried out on the first coordinate system current and the second coordinate system voltage through the second control circuit, and the six-phase current at the input end of the six-phase motor is adjusted according to the first coordinate system voltage and the second coordinate system voltage after ipark conversion, so that the phase current imbalance phenomenon can be effectively suppressed, the harmonic wave can be reduced, and the six-phase PMSM efficiency can be improved.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments or the conventional technologies of the present application, the drawings used in the descriptions of the embodiments or the conventional technologies will be briefly introduced below, it is obvious that the drawings in the following descriptions are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
FIG. 1 is a schematic circuit diagram of a dual d-q axis six-phase PMSM control device according to an embodiment of the present application;
FIG. 2 is a schematic circuit diagram of a dual d-q axis six-phase PMSM control device provided in an embodiment of the present application;
fig. 3 is a schematic circuit diagram of an adaptive notch filter according to an embodiment of the present application;
fig. 4 is a circuit diagram of a filter circuit according to an embodiment of the present application;
fig. 5 is a block diagram of a six-phase PMSM system according to an embodiment of the present disclosure.
Description of reference numerals:
10. a six-phase PMSM control device based on double d-q axes; 100. a current detection circuit; 101. a six-phase motor; 20. a six-phase PMSM system; 200. a rotor detection device; 300. a first control circuit; 310. a current conversion unit; 320. a first coordinate conversion unit; 330. a second coordinate conversion unit; 340. a processing unit; 400. a harmonic suppression circuit; 410. a first processing unit; 420. an adaptive control unit; 500. a second control circuit; 510. a third coordinate conversion unit; 520. a fourth coordinate conversion unit; 530. an SVPWM unit; 600. an inverter circuit; 601. a power source; 700. and a filter circuit.
Detailed Description
In order to make the aforementioned objects, features and advantages of the present application more comprehensible, embodiments accompanying the present application are described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. This application is capable of embodiments in many different forms than those described herein and those skilled in the art will be able to make similar modifications without departing from the spirit of the application and it is therefore not intended to be limited to the embodiments disclosed below.
The numbering of the components as such, e.g., "first", "second", etc., is used herein for the purpose of describing the objects only, and does not have any sequential or technical meaning. The term "connected" and "coupled" when used in this application, unless otherwise indicated, includes both direct and indirect connections (couplings). In the description of the present application, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience in describing the present application and for simplicity in description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, are not to be considered as limiting the present application.
In this application, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through intervening media. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.
It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.
Referring to fig. 1, an embodiment of the present application provides a dual d-q axis based six-phase
The
It is understood that the specific circuit structure of the
In one embodiment, the
In one embodiment, the
The park transformation module performs αβ/dq transformation on the coordinate system current of the stationary coordinate system α - β according to the current angle of the rotor detected by the
In one embodiment, the
coordinate system current iα、iβ、i'αAnd i'βThe x and y components of the Z1 and Z2 spaces are obtained after the transformation of the formula. Then, the x and y components are respectively subjected to alternating current to direct current conversion to obtain the first direct current and the second direct current.
In one embodiment, the
The
In one embodiment, the
In this embodiment, the
Referring to fig. 2, in one embodiment, the
In one embodiment, the first processing unit 410 may include a VSD transform unit and a transform matrix. The VSD conversion unit can be used for respectively subtracting a first coordinate current in a first coordinate system current from a first coordinate current in a second coordinate system current to obtain a first component current, and subtracting a second coordinate current in the first coordinate system current from a second coordinate current in the second coordinate system current to obtain a second component current. The current transformation of the VSD transformation unit can adopt the above current transformation formula, and is not described herein again. In one embodiment, the first component current and the second component current are both alternating currents. The first and second component currents may be converted into the first and second direct currents by a transformation matrix. Specifically, the transformation matrix is as follows:
the first component current can be converted into the first direct current, and the second component current can be converted into the second direct current by using the transformation matrix.
In one embodiment, the
In one embodiment, the adaptive control unit 420 may be an adaptive notch filter. The adaptive notch filter needs to filter out relatively single noise component, that is, the noise signal has strong regularity. Therefore, the noise signal can be selected as the reference signal d (n), and the output y (n) of the trap is close enough to d (n) so as to be equivalent to extracting the noise signal. The specific structure of the adaptive notch filter can be as shown in fig. 3: the system comprises a notch frequency calculation unit, a sine and cosine signal generation unit, a variable parameter filter unit and an LMS adaptive algorithm unit.
The notch frequency calculation unit calculates the frequency of the phase current fundamental wave 6 th harmonic in real time according to the current motor rotating speed of the six-
{f}Hz={n}r/min·p/60·6=0.1·p·{n}r/min|。
a sine and cosine signal generating unit generates a sine signal sin (2 pi ft) and a cosine signal cos (2 pi ft) based on the notch frequency f obtained by the notch frequency calculating unit.
The variable parameter filter unit may be composed of a second order weight matrix, and the weighted sum of the sine and cosine signals is the output value y (n) of the filter unit. The reference signal implicit in the structure is actually a harmonic current signal, namely a supposed harmonic signal, which is an initial phase of the harmonic signal, so that according to the operational relationship of a trigonometric function:
=A sin(2πft+θ0)=A cosθ0·sin(2πft)+Asinθ0·cos(2πft);
then omega1(k) And ω2(k) The convergence value, i.e. the optimal weight value, of (1) is:
ωopt=[ω1,opt(k),ω2,opt(k)]=[A cosθ0,A sinθ0];
the weight matrix continuously corrects the weights of sine and cosine terms according to an LMS adaptive algorithm to minimize the mean square error of an error signal, and the output y (n) of the filter is close to the current harmonic component sufficiently.
The LMS self-adaptive algorithm unit carries out iterative operation according to the input error information and the output value of the sine and cosine generator, and ensures that each weight value converges to the optimal solution. The specific algorithm of the notch trap is as follows:
by using the adaptive control unit 420, the higher harmonics can be effectively tracked, and the phase current imbalance can be effectively suppressed.
In one embodiment, the
The second coordinate
In one embodiment, the
In one embodiment, the first coordinate
In one embodiment, the
Therefore, by the cooperation of the
In one embodiment, the
In one embodiment, the third coordinate conversion unit 510 may be an ipark transform unit. The ipark transform unit performs ipark transform (dq/α β) on the first coordinate system voltage and outputs a first coordinate system modulation voltage to the
In one embodiment, the dual d-q axis based six-phase
In one embodiment, the
In one embodiment, the dual d-q axis based six-phase
In an embodiment, as shown in fig. 4, when the
Referring to fig. 5, another embodiment of the present application provides a six-phase PMSM system 20, including: a six-
In summary, in the present application, the
The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.