CN110376520B - Motor parameter acquisition device, motor and motor parameter acquisition method thereof - Google Patents

Motor parameter acquisition device, motor and motor parameter acquisition method thereof Download PDF

Info

Publication number
CN110376520B
CN110376520B CN201910755599.2A CN201910755599A CN110376520B CN 110376520 B CN110376520 B CN 110376520B CN 201910755599 A CN201910755599 A CN 201910755599A CN 110376520 B CN110376520 B CN 110376520B
Authority
CN
China
Prior art keywords
motor
voltage
analog
phase voltage
digital conversion
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201910755599.2A
Other languages
Chinese (zh)
Other versions
CN110376520A (en
Inventor
刘涛
夏培培
王长恺
区均灌
许凤霞
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Gree Electric Appliances Inc of Zhuhai
Original Assignee
Gree Electric Appliances Inc of Zhuhai
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Gree Electric Appliances Inc of Zhuhai filed Critical Gree Electric Appliances Inc of Zhuhai
Priority to CN201910755599.2A priority Critical patent/CN110376520B/en
Publication of CN110376520A publication Critical patent/CN110376520A/en
Application granted granted Critical
Publication of CN110376520B publication Critical patent/CN110376520B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/34—Testing dynamo-electric machines

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Control Of Ac Motors In General (AREA)
  • Control Of Electric Motors In General (AREA)

Abstract

The invention discloses a motor parameter acquisition device, a motor and a motor parameter acquisition method thereof, wherein the device comprises: the sampling unit is used for collecting phase voltage of the motor; the analog-to-digital conversion unit is used for carrying out analog-to-digital conversion processing on the acquired phase voltage of the motor so as to obtain a digital signal with a set digit; the signal processing unit is used for filtering and extracting the digital signal obtained by the analog-digital conversion processing to obtain sampling parameters linearly related to the average voltage value of the sampled phase voltage of the motor in the PWM period of the motor; and the motor controller is used for carrying out proportional operation according to the sampling parameters so as to obtain the average voltage value of the sampled phase voltage of the motor in the PWM period of the motor. The scheme of the invention can solve the problem of high measurement difficulty of measuring the actual numerical value of the motor phase voltage according to the motor PWM voltage signal, and achieves the effect of reducing the measurement difficulty.

Description

Motor parameter acquisition device, motor and motor parameter acquisition method thereof
Technical Field
The invention belongs to the technical field of motors, and particularly relates to a motor parameter acquisition device, a motor and a motor parameter acquisition method thereof, in particular to a motor phase voltage high-precision sampling device based on the Delta-Sigma principle, a motor and a motor parameter acquisition method thereof.
Background
At present, a mainstream permanent magnet synchronous motor control algorithm is a control method based on Space Vector Pulse Width Modulation (SVPWM), and based on the algorithm, a voltage obtained by a permanent magnet synchronous motor is a Pulse Width Modulation (PWM) voltage (such as a pulse signal) with different duty ratios. In an application scenario where motor voltage needs to be detected, an actual value of a motor phase voltage is generally estimated by obtaining a voltage reference value output by a controller (such as a chip of an MCU microprocessor) and considering voltage drop of an inverter. However, the voltage drop of the inverter is affected by other non-linear factors such as dead time, on/off time of the switch, tube voltage drop, amplitude of bus voltage and current magnitude, so that it is difficult to accurately obtain the voltage drop of the inverter, which results in high estimation difficulty and low precision.
Currently, it is difficult to measure the actual value of the motor phase voltage (the average voltage value within a PWM period) from the motor PWM voltage signal using the conventional method. For example: the current measuring method is mainly an area equivalent method, and an average value of the motor phase voltage is calculated by collecting the waveform in a phase voltage PWM period and confirming the duty ratio and the amplitude of the level at two ends of the bus voltage through an oscilloscope or a special instrument with high sampling rate. For another example: setting the PWM period as T and the bus voltage as U, and acquiring high level time T by capturing timingonSo as to obtain the average voltage Uavg ═ U (t) in the PWM periodonT). The method for calculating the actual duty ratio by using the FPGA is suitable for the condition that the level amplitudes at two ends of the bus voltage are known, needs an additional special high-sampling-rate instrument, has extremely high cost and does not have universality.
The above is only for the purpose of assisting understanding of the technical aspects of the present invention, and does not represent an admission that the above is prior art.
Disclosure of Invention
The invention aims to provide a motor parameter acquisition device, a motor and a motor parameter acquisition method thereof aiming at the defects, so as to solve the problem of high measurement difficulty in measuring the actual value of the motor phase voltage according to the motor PWM voltage signal and achieve the effect of reducing the measurement difficulty.
The invention provides a motor parameter acquisition device, comprising: the device comprises a sampling unit, an analog-to-digital conversion unit, a signal processing unit and a motor controller; the sampling unit is used for collecting phase voltage of the motor; the analog-to-digital conversion unit is used for carrying out analog-to-digital conversion processing on the acquired phase voltage of the motor so as to obtain a digital signal with a set digit; the signal processing unit is used for filtering and extracting the digital signal obtained by the analog-digital conversion processing to obtain a sampling parameter which is linearly related to the average voltage value of the sampled phase voltage of the motor in the PWM period of the motor; and the motor controller is used for carrying out proportional operation according to the sampling parameters so as to obtain the average voltage value of the sampled phase voltage of the motor in the PWM period of the motor.
Optionally, the sampling unit includes: the device comprises a voltage division module and a sampling module; the voltage division module and the sampling module are connected in series between a phase voltage measuring point of the motor and a bus voltage low-level end of the motor; the sampling module is connected in parallel between the positive phase input end of the analog-to-digital conversion module and the negative phase input end of the analog-to-digital conversion module.
Optionally, the voltage dividing module includes: a first resistor; the sampling module comprises: a second resistor; the resistance value of the first resistor and the resistance value of the second resistor are both above a set resistor threshold value, so that the voltage at two ends of the second resistor meets the set voltage input range of the analog-to-digital conversion unit.
Optionally, the analog-to-digital conversion unit includes: an analog Delta-Sigma modulator; the modulation clock of the analog Delta-Sigma modulator is synchronous with the output rate of the signal processing unit; and the processing frequency of the signal processing unit is the same as the PWM frequency of the motor.
Optionally, the analog Delta Sigma modulator is a Delta Sigma modulator of a second order or more.
Optionally, the signal processing unit includes: a filter and decimation module; the filter and the extraction module are sequentially arranged between the analog-to-digital conversion unit and the motor controller.
Optionally, the filter includes: a sinc digital filter; the extraction module is provided with a set extraction rate.
Optionally, the method further comprises: a reference unit; the reference unit is used for providing reference supply voltage for the analog-to-digital conversion unit.
In accordance with another aspect of the present invention, there is provided a motor including: the motor parameter acquisition device is described above.
In another aspect, the present invention provides a motor parameter collecting method for a motor, including: collecting phase voltage of a motor; carrying out analog-to-digital conversion processing on the acquired phase voltage of the motor to obtain a digital signal with a set digit; filtering and extracting the digital signal obtained by the analog-digital conversion processing to obtain a sampling parameter which is linearly related to the average voltage value of the sampled phase voltage of the motor in the PWM period of the motor; and carrying out proportional operation according to the sampling parameters to obtain the average voltage value of the sampled phase voltage of the motor in the PWM period of the motor.
According to the scheme of the invention, the voltage value is obtained through the FPGA or a standard peripheral using a microprocessor, the numerical value of the bus voltage is not needed, the motor phase voltage numerical value can be obtained in real time, the measurement difficulty is small, the precision is high, and the cost is low.
Furthermore, according to the scheme of the invention, the average voltage of the motor in the PWM period can be measured in real time by adopting the Delta-Sigma single ADC chip, namely, the high-precision measurement of the PWM phase voltage of the motor is realized, the measurement precision is high, the operation process is simple, and the cost is low.
Furthermore, according to the scheme of the invention, the Delta-Sigma ADC is used for sampling the motor phase voltage, the throughput rate of the digital extraction filter is set to be the same as the PWM modulation frequency, the average voltage value of the motor phase voltage in the PWM control period is measured in real time on line, and the method and the device are simple in structure, easy to implement, high in precision, low in cost and high in universality.
Therefore, according to the scheme of the invention, the Delta-Sigma ADC is used for sampling the motor phase voltage, the throughput rate of the digital extraction filter is set to be the same as the PWM modulation frequency, the average voltage value of the motor phase voltage in a PWM period can be acquired on line in real time, the problem of high measurement difficulty in measuring the actual value of the motor phase voltage according to the motor PWM voltage signal is solved, and the effect of reducing the measurement difficulty is achieved.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.
The technical solution of the present invention is further described in detail by the accompanying drawings and embodiments.
Drawings
Fig. 1 is a schematic structural diagram of an embodiment of a motor parameter acquisition device according to the present invention;
FIG. 2 is a signal chain of the Delta-Sigma ADC conversion of the embodiment of the motor parameter acquisition device of the present invention;
fig. 3 is a schematic structural diagram of a preferred embodiment of the motor parameter acquisition device of the present invention, specifically, a schematic diagram of a motor phase voltage measurement principle based on the Delta-Sigma principle;
FIG. 4 is a schematic diagram of a graph of actual phase voltage measurements for one embodiment of the motor parameter acquisition device of the present invention;
fig. 5 is a schematic flow chart of an embodiment of a motor parameter acquisition method according to the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the specific embodiments of the present invention and the accompanying drawings. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
According to an embodiment of the invention, a motor parameter acquisition device is provided. Referring to fig. 1, a schematic diagram of an embodiment of the apparatus of the present invention is shown. This motor parameter acquisition device can include: the device comprises a sampling unit, an analog-to-digital conversion unit, a signal processing unit and a motor controller. The sampling unit is arranged between a phase voltage detection end of the motor and a signal input end of the analog-to-digital conversion unit. And the signal output end of the analog-to-digital conversion unit is connected to the signal input end of a motor controller of the motor.
In an optional example, the sampling unit is disposed at a phase voltage detection end of the motor, and may be configured to collect a phase voltage of the motor. The phase voltage of the motor acquired by the acquisition may include: phase voltages of a certain phase, or phase voltages of a certain phase.
Optionally, the sampling unit may include: the device comprises a voltage division module and a sampling module.
The voltage division module and the sampling module are connected in series between a phase voltage measuring point of the motor and a low voltage level end of a bus bar of the motor. And the first connecting end of the voltage division module is connected to a phase voltage measuring end of the motor. And the second connecting end of the voltage division module is connected to the positive phase input end of the analog-to-digital conversion module. The sampling module is connected in parallel between the positive phase input end of the analog-to-digital conversion module and the negative phase input end of the analog-to-digital conversion module.
For example: the voltage across the resistor R2 meets the voltage input range of the Delta-Sigma modulator by serially connecting resistors R1 and R2 with proper resistance value, low inductance value and high precision. Measuring to obtain voltage values at two ends of the resistor R1, and obtaining an average voltage value of the motor phase voltage in a PMW period in real time on line through proportion conversion; where the delay due to sampling and filtering depends on the different structure types.
From this, constitute the sampling unit through partial pressure module and sampling module, simple structure, and can guarantee security and the precision to motor phase voltage sampling.
More optionally, the voltage dividing module may include: a first resistor. The sampling module may include: a second resistor.
The resistance value of the first resistor and the resistance value of the second resistor are both above a set resistor threshold value, so that the voltage at two ends of the second resistor meets the set voltage input range of the analog-to-digital conversion unit.
For example: a voltage dividing resistor R1 and a sampling resistor R2 are connected in series between a motor phase voltage measuring point and a bus voltage low level, a resistor with a large resistance value is suitable for R1 and R2, and the resistance value of the resistor R2 is limited by a Delta-Sigma modulator. And the two ends of the sampling resistor R2 are connected to the input end of the Delta-Sigma modulator in parallel.
Therefore, voltage division and sampling are achieved by using the resistor, and the resistance form of the resistor is set, so that the sampling accuracy and reliability can be guaranteed.
In an optional example, the analog-to-digital conversion unit is disposed at an output side of the sampling unit, and may be configured to perform analog-to-digital conversion processing on the acquired phase voltage of the motor to obtain a digital signal with a set number of bits.
Optionally, the analog-to-digital conversion unit may include: an analog Delta Sigma modulator.
And the modulation clock of the analog Delta-Sigma modulator is synchronous with the output rate of the signal processing unit, and the processing frequency of the signal processing unit is the same as the PWM frequency of the motor.
For example: based on a widely applied Delta-Sigma ADC chip, the voltage value is acquired through an FPGA or a standard peripheral using a microprocessor, the numerical value of bus voltage is not needed, and the motor phase voltage numerical value can be acquired in real time. Of course, in practical application, the line voltage of the motor can also be measured by the method.
For example: by adopting a Delta-Sigma single ADC chip, the duty ratio analysis of the PWM voltage signal is not carried out, so that the level amplitude values at two ends of the bus voltage are not required to be known. The bus voltage is unknown, the scheme of the invention can measure the average voltage of the motor in a PWM period in real time, namely, the high-precision measurement of the PWM phase voltage of the motor is realized, the measurement precision is high, the operation process is simple, and the cost is low.
For example: the Delta-Sigma ADC is used for sampling the motor phase voltage, the throughput rate of the digital decimation filter is set to be the same as the PWM modulation frequency, and the average voltage value of the motor phase voltage in a PWM period can be acquired in real time on line.
Therefore, analog-to-digital conversion is carried out by using the analog Delta-Sigma modulator, and the modulation clock is set according to the output rate of the signal processing unit, so that the sampled phase voltage of the motor can be subjected to analog-to-digital conversion more timely and accurately.
More optionally, the analog Delta Sigma modulator is a Delta Sigma modulator of a second order or more.
For example: analog Delta Sigma modulators typically choose second order and above structures.
For example: the Delta-Sigma modulator outputs 1-bit digital signals (code stream) to the digital signal processing module. When the digital signal processing frequency is the same as the PWM frequency, the digital signal processing module filters and extracts the 1-bit code stream, a numerical value linearly related to the average voltage value of the phase voltage in the PWM period can be obtained, and the average voltage value of the motor phase voltage in the PWM period can be obtained through scaling by the operation processor.
Therefore, the Delta-Sigma modulator with the second order or more is selected, so that the processing efficiency is high, and the processing result is accurate.
In an optional example, the signal processing unit, disposed between the analog-to-digital conversion unit and the motor controller of the motor, may be configured to perform filtering and decimation processing on the digital signal obtained by the analog-to-digital conversion processing, so as to obtain a sampling parameter that is linearly related to an average voltage value of the sampled phase voltage of the motor within a PWM period of the motor.
For example: and (3) carrying out data processing on the code stream (such as a 1-bit digital signal) output by the Delta-Sigma by using a digital signal processing module. The scheme of the invention can be realized by various solutions and has flexible design.
Optionally, the signal processing unit may include: a filter and a decimation module. The filter and the extraction module are sequentially arranged between the analog-to-digital conversion unit and the motor controller.
For example: the filter and the extraction module form a digital signal processing module which is used for processing the signal output by the Delta-Sigma modulator to obtain the voltage value of the required motor phase voltage.
For example: through setting a Delta-Sigma modulator clock and selecting a digital decimation filter with proper throughput rate, the throughput rate (digital conversion output rate) of the digital signal processor is matched with the PWM switching frequency, namely the two rates are equal and synchronous, and the motor phase voltage value can be acquired online in real time at the same rate.
Therefore, through the matching arrangement of the filter and the extraction module, the filtering and extraction processing of the digital signals output by the analog-digital conversion unit can be realized, the structure is simple, and the processing effect is good.
More optionally, the filter may include: a sinc digital filter. The extraction module is provided with a set extraction rate.
For example: the filter for digital signal processing generally selects sinc3 or sinc5+ sinc1 for digital filtering.
Therefore, the filtering and the extraction of the digital signals can be more efficiently and accurately realized by setting the form of the filter and the extraction rate of the extraction module.
In an optional example, the motor controller, disposed at the output side of the signal processing unit, may be configured to perform a scaling operation according to the sampling parameter to obtain an average voltage value of the sampled phase voltage of the motor in a PWM period of the motor.
For example: the modulation clock of Delta-Sigma and the throughput rate (equal to the digital conversion output rate) of the digital signal processing module can be adjusted to match the processing rate of Delta-Sigma ADC with the frequency of PWM voltage, so that the average value of the voltage at two ends of the divider resistor in the PWM period can be obtained, and the average voltage value of the phase voltage in the PWM period can be obtained in real time on line through scaling.
Therefore, the phase voltage of the motor is acquired, analog-to-digital conversion and signal processing are carried out on the phase voltage and then the phase voltage is sent to the motor controller, and the average voltage value of the phase voltage of the motor in the PWM period of the motor is obtained through proportional operation, so that the average voltage value is simple and convenient to obtain, the obtained result is accurate, and the cost is low.
In an alternative embodiment, the method may further include: a reference unit. The reference unit is arranged at a power supply end of the analog-to-digital conversion unit and can be used for providing a reference power supply voltage for the analog-to-digital conversion unit.
Therefore, the reference power supply voltage of the analog-digital conversion unit is set, and the working reliability of the analog-digital conversion unit is favorably improved.
Through a large number of tests, the technical scheme of the invention realizes the acquisition of the voltage value through the FPGA or standard peripheral equipment using a microprocessor, does not need the numerical value of the bus voltage, can acquire the motor phase voltage numerical value in real time, and has the advantages of small measurement difficulty, high precision and low cost.
According to the embodiment of the invention, the motor corresponding to the motor parameter acquisition device is also provided. The motor may include: the motor parameter acquisition device is described above.
In an optional implementation mode, the scheme of the invention provides a motor phase voltage high-precision sampling method based on the Delta-Sigma principle, the method is based on a widely applied Delta-Sigma ADC chip, the voltage value is acquired through an FPGA or a standard peripheral device using a microprocessor, the numerical value of bus voltage is not needed, and the motor phase voltage numerical value can be acquired in real time. Of course, in practical application, the line voltage of the motor can also be measured by the method.
In the scheme of the invention, the mainstream motor controllers adopt FPGA or a microprocessing control chip. Therefore, by adopting the scheme of the invention, the high-precision measurement of the motor phase voltage can be realized only by adding the Delta-Sigma ADC to the original motor control hardware and writing a proper code in software, and the invention has low cost and strong universality. In the scheme of the invention, the motor phase voltage is acquired based on the Delta-Sigma principle.
Among them, the Delta Sigma ADC, i.e., the Sigma-Delta analog-to-digital converter, is one of analog-to-digital converters, which are a type of device for converting a continuous signal in an analog form into a discrete signal in a digital form.
Furthermore, in the scheme of the present invention, a digital signal processing module may be further utilized to perform data processing on a code stream (such as a 1-bit digital signal) output by Delta-Sigma. The scheme of the invention can be realized by various solutions and has flexible design. Such as: there are at least the following 3 solutions to implement data processing on the signal output by the Delta Sigma chip.
For example: the digital signal processing module can be realized by using any FPGA chip; any chip with a sinc filter can also be used, such as: a processor of model ADSP-CM40 x; the use of processors that support sinc filters (i.e., filters constructed from sinc functions) may also be adapted, such as: model MSC1202Y 28051. Of course, the filter chips and processor types of the FPGA and sinc are many and can be selected and used as needed.
In the scheme of the invention, a Delta-Sigma single ADC chip is adopted, and the duty ratio analysis is not carried out on the PWM voltage signal, so that the level amplitudes at two ends of the bus voltage are not required to be known. The bus voltage is unknown, the scheme of the invention can measure the average voltage of the motor in a PWM period in real time, namely, the high-precision measurement of the PWM phase voltage of the motor is realized, the measurement precision is high, the operation process is simple, and the cost is low.
In an optional example, according to the scheme of the invention, a Delta-Sigma type ADC is used for sampling the motor phase voltage, the throughput rate of a digital decimation filter is set to be the same as the PWM modulation frequency, and the average voltage value of the motor phase voltage in a PWM period can be acquired online in real time. The scheme has simple structure and is easy to realize.
Therefore, the scheme of the invention can measure the average voltage value of the motor phase voltage in the PWM control period in real time on line, has simple structure, does not need a special instrument with high sampling rate, only needs to add a Delta-Sigma ADC chip on the original hardware and compile a proper code, and has easy realization, high precision, low cost and strong universality. The motor phase voltage obtained by the measurement of the invention can be used for real-time monitoring of the motor state, optimization of a motor control algorithm and the like.
In an alternative embodiment, a specific implementation process of the scheme of the present invention can be exemplarily described with reference to the examples shown in fig. 2 to 4.
In an alternative embodiment, the scheme of the invention provides a scheme for measuring the average voltage of the motor in a PWM period on line in real time. The protocol uses a Delta-Sigma based ADC for voltage measurement. FIG. 2 is a flow chart of the signal chain in the voltage sampling of the Delta-Sigma ADC. The digital signal processing device mainly comprises two parts, wherein the first part is an analog Delta-Sigma modulator, and the second part is a digital signal processing module.
Alternatively, analog Delta-Sigma modulators typically choose second order and above structures. The prior art does not have a scheme for converting an analog signal and a digital signal of a motor phase voltage by using a Delta-Sigma modulator.
Alternatively, the filter for digital signal processing generally selects sinc3 or sinc5+ sinc1 digital filtering. In the scheme of the invention, the used digital signal processing module has various solutions and is flexible in design. The prior art does not have a case of using a Delta-Sigma modulator for motor phase voltage measurement. In the scheme of the invention, the digital signal processing module must support Delta-Sigma signal demodulation.
In the scheme of the invention, the processing rate of the Delta-Sigma ADC is matched with the frequency of the PWM voltage by adjusting the modulation clock for setting Delta-Sigma and the throughput rate (equal to the digital conversion output rate) of the digital signal processing module, the average value of the voltage at two ends of the voltage dividing resistor in the PWM period can be obtained, and the average voltage value of the phase voltage in the PWM period can be obtained in real time on line by scaling.
In an alternative embodiment, fig. 3 is a schematic diagram of a motor phase voltage high-precision measurement implementation of the Delta Sigma principle of the present invention, and the following is a specific embodiment.
The voltage across the resistor R2 meets the voltage input range of the Delta-Sigma modulator by serially connecting resistors R1 and R2 with proper resistance value, low inductance value and high precision. And measuring to obtain the voltage value at two ends of the resistor R1, and obtaining the average voltage value of the motor phase voltage in the PMW period in real time on line through proportion conversion. Where the delay due to sampling and filtering depends on the different structure types.
In fig. 3, resistors R1 and R2 perform voltage division, and the function is to make the voltage across the charge resistor R2 satisfy the input range of the Delta Sigma modulator.
In fig. 3, a Delta Sigma modulator, i.e., a Delta Sigma type ADC chip, such as AD7403, MAX11200, AD7710, etc., where the Delta Sigma chip has many types and can be selected according to actual needs; the function is to realize the conversion of analog signals into digital signals and the digital conversion output of the voltage at the two ends of the measuring resistor R2.
In fig. 3, the reference input is used to provide the required operating voltage of the Delta Sigma modulator, for example, AD7403 needs stable 5V, AD7710 needs 5V or 10V operating voltage, and so on.
In fig. 3, the filter and the decimation module constitute a digital signal processing module, which is used for processing the signal output by the Delta Sigma modulator to obtain the voltage value of the required motor phase voltage.
In fig. 3, a motor control arithmetic processor, i.e., a motor control CPU, is a CPU chip that can meet any arithmetic requirements, and is used to implement the arithmetic of the motor control algorithm. For example, the ARM Cortex R4 has various specific chip types, can be selected according to the motor control operation data volume, and is also supported by a CPU (central processing unit) in a mobile phone or a computer.
As shown in fig. 3, a voltage dividing resistor R1 and a sampling resistor R2 are connected in series between a motor phase voltage measuring point and a bus voltage low level, R1 and R2 are suitable for selecting resistors with large resistance values, and the resistance value of the resistor R2 is limited by a Delta-Sigma modulator. And the two ends of the sampling resistor R2 are connected to the input end of the Delta-Sigma modulator in parallel. The Delta-Sigma modulator outputs 1-bit digital signals (code stream) to the digital signal processing module. When the digital signal processing frequency is the same as the PWM frequency, the digital signal processing module filters and extracts the 1-bit code stream, a numerical value linearly related to the average voltage value of the phase voltage in the PWM period can be obtained, and the average voltage value of the motor phase voltage in the PWM period can be obtained through scaling by the operation processor. In practice, the Delta-Sigma modulator, the digital signal processing module and the arithmetic processor can be mutually independent in hardware, and integrated chips with different combinations are also provided, so that various realization forms are realized.
For scaling, see the example shown in fig. 2. As shown in fig. 2, the digital signal processing module performs filtering extraction on the 1-bit code stream to obtain an average voltage value of the and-phase voltage in the PWM period, which is the voltage U2 across the resistor R2. The negative terminal of the inverter is set to be the voltage 0V, and the voltage U12 across the series resistors R1 and R2 is the phase voltage to be measured by the present invention. U1 and U12 both represent the average voltage value over the PWM cycle. Since the input impedance of Delta-Sigma is very large, the currents flowing through R1 and R2 are nearly equal, and a proportional relation can be obtained through a voltage division formula, namely U12/(R1+ R2) ═ U2/R2. Thus, the phase voltage U12 to be measured is U2 (R1+ R2)/R2.
For example: when a Delta-Sigma ADC chip AD7403 is used, the ideal input measurement range is-250 mV to +250mV, a resistor R2 is selected to be 680 omega, a resistor R1 is 1M omega, a digital signal processing module filters and extracts 1-bit code stream, a voltage value U2 can be obtained, and if U2 is 120mV, the phase voltage of the motor to be measured:
U12＝U2*(R1+R2)/R2＝120mV*(680Ω+1MΩ)/680Ω＝176.60V。
alternatively, the throughput rate (digital conversion output rate) of the digital signal processor is matched with the PWM switching frequency by setting the Delta-Sigma modulator clock and selecting a digital decimation filter with proper throughput rate, namely the two rates are equal and synchronous, so that the motor phase voltage value can be acquired online in real time at the same rate. Fig. 3 shows the collection of the voltage of only one phase of the three-phase motor, and actually, the scheme of the invention can also be used for simultaneously measuring multiple phase voltages.
For example: when the PWM voltage frequency is fPWMSelecting a second-order Delta-Sigma modulator, setting a proper modulation clock MCLK, selecting a sinc3 digital filter, setting a reasonable extraction rate DEC, selecting a high-frequency modulation clock according to the performance of the Delta-Sigma modulator, and meeting the requirement that MCLK/DEC is fPWMThus, the method of the present invention is realized.
Fig. 4 shows that motor phase voltage data is actually acquired in real time, the frequency of an experimental platform PMW is 10kHz, the clock of a Delta-Sigma modulator is 10.24MHz, a sinc3 filter is selected, the extraction rate is set to be 1024, and the rate of a digital signal processing module is 10kHz, which is equivalent to the PWM frequency. As can be seen from FIG. 4, the method of the invention can realize high-precision sampling of the motor phase voltage.
In conclusion, the scheme of the invention for high-precision sampling of the motor phase voltage based on the Delta-Sigma principle does not depend on the amplitude of the bus voltage, does not need special equipment with high sampling rate, and greatly reduces the cost; various solutions are possible and the design is flexible only through the combination of the Delta-Sigma modulator, the digital signal processing module and the arithmetic processor.
The circuit diagram described above is a circuit structure, and the specific resistance value, the sampling structure, the filter structure, and the type of MCU (processing chip such as FPGA) can be adjusted and selected as needed.
Since the processes and functions implemented by the motor of this embodiment substantially correspond to the embodiments, principles and examples of the devices shown in fig. 1 to 4, the description of this embodiment is not detailed, and reference may be made to the related descriptions in the foregoing embodiments, which are not described herein again.
A large number of tests prove that by adopting the technical scheme of the invention and adopting the Delta-Sigma single ADC chip, the average voltage of the motor in the PWM period can be measured in real time, namely the high-precision measurement of the PWM phase voltage of the motor is realized, the measurement precision is high, the operation process is simple, and the cost is low.
According to an embodiment of the present invention, a method for acquiring a motor parameter of a motor corresponding to the motor is also provided, as shown in fig. 5, which is a schematic flow chart of an embodiment of the method of the present invention. The motor parameter acquisition method of the motor can comprise the following steps: step S110 to step S140.
At step S110, a phase voltage of the motor is collected by a sampling unit provided at a phase voltage detection terminal of the motor. Wherein, the looks voltage of the motor that the collection obtained includes: phase voltages of a certain phase, or phase voltages of a certain phase.
At step S120, the analog-to-digital conversion processing is performed on the acquired phase voltage of the motor through an analog-to-digital conversion unit disposed at the output side of the sampling unit to obtain a digital signal with a set number of bits.
In step S130, a filtering extraction process is performed on the digital signal obtained by the analog-to-digital conversion process by a signal processing unit disposed between the analog-to-digital conversion unit and the motor controller of the motor, so as to obtain a sampling parameter linearly related to the average voltage value of the sampled phase voltage of the motor within the PWM period of the motor.
At step S140, a proportional operation is performed according to the sampling parameter by a motor controller disposed at the output side of the signal processing unit to obtain an average voltage value of the sampled phase voltage of the motor in the PWM period of the motor.
For example: the modulation clock of Delta-Sigma and the throughput rate (equal to the digital conversion output rate) of the digital signal processing module can be adjusted to match the processing rate of Delta-Sigma ADC with the frequency of PWM voltage, so that the average value of the voltage at two ends of the divider resistor in the PWM period can be obtained, and the average voltage value of the phase voltage in the PWM period can be obtained in real time on line through scaling.
Therefore, the phase voltage of the motor is acquired, analog-to-digital conversion and signal processing are carried out on the phase voltage and then the phase voltage is sent to the motor controller, and the average voltage value of the phase voltage of the motor in the PWM period of the motor is obtained through proportional operation, so that the average voltage value is simple and convenient to obtain, the obtained result is accurate, and the cost is low.
Since the processing and functions implemented by the method of this embodiment substantially correspond to the embodiments, principles and examples of the motor, reference may be made to the related descriptions in the foregoing embodiments without being detailed in the description of this embodiment, which is not described herein.
Through a large number of tests, the technical scheme of the embodiment is adopted, the Delta-Sigma ADC is used for sampling the phase voltage of the motor, the throughput rate of the digital extraction filter is set to be the same as the PWM modulation frequency, the average voltage value of the phase voltage of the motor in the PWM control period is measured in real time on line, and the digital extraction filter is simple in structure, easy to achieve, high in precision, low in cost and high in universality.
In summary, it is readily understood by those skilled in the art that the advantageous modes described above can be freely combined and superimposed without conflict.
The above description is only an example of the present invention, and is not intended to limit the present invention, and it is obvious to those skilled in the art that various modifications and variations can be made in the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.

Claims (10)

1. The utility model provides a motor parameter acquisition device which characterized in that includes: the device comprises a sampling unit, an analog-to-digital conversion unit, a signal processing unit and a motor controller; wherein,
the sampling unit is used for collecting phase voltage of the motor;
the analog-to-digital conversion unit is used for carrying out analog-to-digital conversion processing on the acquired phase voltage of the motor so as to obtain a digital signal with a set digit;
the signal processing unit is used for filtering and extracting the digital signal obtained by the analog-digital conversion processing to obtain a sampling parameter which is linearly related to the average voltage value of the sampled phase voltage of the motor in the PWM period of the motor;
the motor controller is used for carrying out proportional operation according to the sampling parameter so as to obtain an average voltage value of the phase voltage of the sampled motor in a PWM (pulse-width modulation) period of the motor;
the analog-to-digital conversion unit comprises an analog Delta-Sigma modulator, the signal processing unit comprises a digital signal processing module, the digital signal processing module supports Delta-Sigma signal demodulation, and the processing rate of the Delta-Sigma ADC is matched with the frequency of the PWM voltage by adjusting the modulation clock for setting Delta-Sigma and the digital conversion output rate of the digital signal processing module.
2. The apparatus of claim 1, wherein the sampling unit comprises: the device comprises a voltage division module and a sampling module; wherein,
the voltage division module and the sampling module are connected in series between a phase voltage measuring point of the motor and a low voltage level end of a bus bar of the motor;
the sampling module is connected in parallel between the positive phase input end of the analog-to-digital conversion module and the negative phase input end of the analog-to-digital conversion module.
3. The apparatus of claim 2, wherein the voltage divider module comprises: a first resistor; the sampling module comprises: a second resistor;
the resistance value of the first resistor and the resistance value of the second resistor are both larger than or equal to a set resistor threshold value, so that the voltage at two ends of the second resistor meets the set voltage input range of the analog-to-digital conversion unit.
4. The apparatus of one of claims 1 to 3, wherein a modulation clock of the analog Delta-Sigma modulator is synchronized with an output rate of the signal processing unit; and the processing frequency of the signal processing unit is the same as the PWM frequency of the motor.
5. The apparatus of claim 4 wherein the analog Delta Sigma modulator is a second or higher order Delta Sigma modulator.
6. The apparatus according to any one of claims 1 to 3, wherein the signal processing unit comprises: a filter and decimation module; the filter and the extraction module are sequentially arranged between the analog-to-digital conversion unit and the motor controller.
7. The apparatus of claim 6, wherein the filter comprises: a sinc digital filter; the extraction module is provided with a set extraction rate.
8. The apparatus of any of claims 1-3, further comprising: a reference unit;
the reference unit is used for providing reference supply voltage for the analog-to-digital conversion unit.
9. An electric machine, comprising: the motor parameter acquisition device of any one of claims 1-8.
10. A motor parameter acquisition method for a motor according to claim 9, comprising:
collecting phase voltage of a motor;
carrying out analog-to-digital conversion processing on the acquired phase voltage of the motor to obtain a digital signal with a set digit;
filtering and extracting the digital signal obtained by the analog-digital conversion processing to obtain a sampling parameter which is linearly related to the average voltage value of the sampled phase voltage of the motor in the PWM period of the motor;
and carrying out proportional operation according to the sampling parameters to obtain the average voltage value of the sampled phase voltage of the motor in the PWM period of the motor.
CN201910755599.2A 2019-08-15 2019-08-15 Motor parameter acquisition device, motor and motor parameter acquisition method thereof Active CN110376520B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201910755599.2A CN110376520B (en) 2019-08-15 2019-08-15 Motor parameter acquisition device, motor and motor parameter acquisition method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201910755599.2A CN110376520B (en) 2019-08-15 2019-08-15 Motor parameter acquisition device, motor and motor parameter acquisition method thereof

Publications (2)

Publication Number Publication Date
CN110376520A CN110376520A (en) 2019-10-25
CN110376520B true CN110376520B (en) 2020-06-30

Family

ID=68259519

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201910755599.2A Active CN110376520B (en) 2019-08-15 2019-08-15 Motor parameter acquisition device, motor and motor parameter acquisition method thereof

Country Status (1)

Country Link
CN (1) CN110376520B (en)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111865150A (en) * 2020-06-22 2020-10-30 中国船舶重工集团公司第七0七研究所 Double SINC filter circuit and filtering method in permanent magnet synchronous motor control system
CN112462257B (en) * 2020-11-06 2021-12-10 珠海格力电器股份有限公司 Motor terminal voltage detection method, device and circuit and air conditioning system
CN113238091B (en) * 2021-05-11 2022-03-29 深圳市星火数控技术有限公司 Motor current sampling method and system based on sinc3 filter and motor
CN115980579B (en) * 2023-02-08 2024-03-08 肇庆小鹏汽车有限公司 Motor detection method, apparatus and storage medium

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003087855A1 (en) * 2002-04-17 2003-10-23 Danfoss Drives A/S Method for measuring currents in a motor controller and motor controller using such method
CN202033391U (en) * 2010-12-30 2011-11-09 上海协同科技股份有限公司 AC sampling device
CN104122439A (en) * 2014-07-29 2014-10-29 中颖电子股份有限公司 Electric energy meter capable of improving phase correction precision
CN104931780A (en) * 2015-05-20 2015-09-23 梧州学院 Synchronous sampling, converting and acquiring device for power harmonic 16-channel signal input
CN204945360U (en) * 2015-07-16 2016-01-06 国家电网公司 The accuracy detecting device of electric energy metered system
CN105915219A (en) * 2016-04-08 2016-08-31 中国科学院微电子研究所 Analog-digital conversion circuit
CN206618803U (en) * 2017-04-19 2017-11-07 宁波中车时代传感技术有限公司 A kind of digital isolation voltage harvester
CN107786139A (en) * 2016-08-25 2018-03-09 美国亚德诺半导体公司 The system and method for determining the parameter of electric machine
CN108955923A (en) * 2018-06-28 2018-12-07 中国电子科技集团公司第二十四研究所 Digital temperature sensor based on sigma-delta ADC

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003087855A1 (en) * 2002-04-17 2003-10-23 Danfoss Drives A/S Method for measuring currents in a motor controller and motor controller using such method
CN1646926A (en) * 2002-04-17 2005-07-27 丹福斯驱动器公司 Method for measuring currents in a motor controller and motor controller using such method
CN202033391U (en) * 2010-12-30 2011-11-09 上海协同科技股份有限公司 AC sampling device
CN104122439A (en) * 2014-07-29 2014-10-29 中颖电子股份有限公司 Electric energy meter capable of improving phase correction precision
CN104931780A (en) * 2015-05-20 2015-09-23 梧州学院 Synchronous sampling, converting and acquiring device for power harmonic 16-channel signal input
CN204945360U (en) * 2015-07-16 2016-01-06 国家电网公司 The accuracy detecting device of electric energy metered system
CN105915219A (en) * 2016-04-08 2016-08-31 中国科学院微电子研究所 Analog-digital conversion circuit
CN107786139A (en) * 2016-08-25 2018-03-09 美国亚德诺半导体公司 The system and method for determining the parameter of electric machine
CN206618803U (en) * 2017-04-19 2017-11-07 宁波中车时代传感技术有限公司 A kind of digital isolation voltage harvester
CN108955923A (en) * 2018-06-28 2018-12-07 中国电子科技集团公司第二十四研究所 Digital temperature sensor based on sigma-delta ADC

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Σ-Δ采样在电机控制中的应用研究;梁桂林 等;《工业控制计算机》;20180825;第142-144页 *

Also Published As

Publication number Publication date
CN110376520A (en) 2019-10-25

Similar Documents

Publication Publication Date Title
CN110376520B (en) Motor parameter acquisition device, motor and motor parameter acquisition method thereof
RU2013106761A (en) DETERMINATION OF THE DIRECTION OF THE SHORT CIRCUIT TO THE EARTH FOR THE MEDIUM OR HIGH VOLTAGE DISTRIBUTION NETWORKS
CN109444559A (en) The method of sampling, method for reconstructing and the device of pulse signal
CN107102193B (en) Signal noise processing device in electric parameter metering process
CN109782054A (en) A kind of alternating voltage commutation difference measurement device and method based on quantum voltage
CN101937017A (en) Dynamic direct-current removing method for intelligent electric meter during alternating-current sampling
CN102707128A (en) Circuit and method for acquiring alternating signal based on microcontroller
TWI361900B (en) Device for accurately measuring amplifier's open-loop gain with digital stimuli
CN110554328A (en) HHT-based storage battery internal resistance measuring method and system
CN106646056A (en) Signal collection circuit and method for single-lithium-battery power supply
CN108241129A (en) Switching power supply output filter capacitor monitoring device and method
CN110850152B (en) PWM converter direct current side support capacitor current sampling and reconstruction method
EP0916956A1 (en) RMS converter for obtaining fast RMS measurements
CN2804881Y (en) AC, DC voltage parallel measuring circuit
CN205157646U (en) Electric energy metering circuit based on voltage controlled oscillator
CN107356799A (en) A kind of electric current delay method of sampling
CN109347397A (en) The current of electric method of sampling and system based on three resistance of three-phase drive bridge lower bridge arm
CN101487863B (en) Apparatus for accurately measuring open circuit gain of amplifier by utilizing digital excitation signal
CN217484401U (en) Transient current acquisition circuit and MCU low-power consumption test system
CN206497161U (en) A kind of battery-powered signal acquisition circuit of single-lithium-battery
US9513319B1 (en) Systems, methods, and devices for energy and power metering
CN209342881U (en) Direct-flow micromachine measures aging equipment
CN206099924U (en) Sawtooth wave produces circuit
CN106597067B (en) The voltage or current measuring device and method of a kind of random waveform arbitrary point
CN109752592A (en) AC/DC signal power integrated measuring device and method

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
CB03 Change of inventor or designer information

Inventor after: Liu Tao

Inventor after: Xia Peipei

Inventor after: Wang Changkai

Inventor after: Qu Junguan

Inventor after: Xu Fengxia

Inventor before: Xia Peipei

Inventor before: Wang Changkai

Inventor before: Qu Junguan

Inventor before: Xu Fengxia

CB03 Change of inventor or designer information
GR01 Patent grant
GR01 Patent grant