CN110716082A - Terminal voltage acquisition and compensation method for improving precision of power-stage motor simulator - Google Patents
Terminal voltage acquisition and compensation method for improving precision of power-stage motor simulator Download PDFInfo
- Publication number
- CN110716082A CN110716082A CN201910914335.7A CN201910914335A CN110716082A CN 110716082 A CN110716082 A CN 110716082A CN 201910914335 A CN201910914335 A CN 201910914335A CN 110716082 A CN110716082 A CN 110716082A
- Authority
- CN
- China
- Prior art keywords
- voltage
- operational amplifier
- terminal voltage
- inverter
- compensation
- 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.)
- Granted
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/25—Arrangements for measuring currents or voltages or for indicating presence or sign thereof using digital measurement techniques
- G01R19/2503—Arrangements for measuring currents or voltages or for indicating presence or sign thereof using digital measurement techniques for measuring voltage only, e.g. digital volt meters (DVM's)
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/32—Compensating for temperature change
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Inverter Devices (AREA)
- Control Of Ac Motors In General (AREA)
Abstract
A terminal voltage acquisition and compensation method for improving the precision of a power level motor simulator relates to an acquisition and compensation method of the output terminal voltage of an inverter of the power level motor simulator, and comprises the following steps: respectively building terminal voltage acquisition circuits of a motor driver and a motor simulator; the terminal voltage acquisition circuit comprises a resistor voltage divider, a first operational amplifier, a second operational amplifier, a third operational amplifier and a DSP; capturing an output signal of the first operational amplifier to obtain a terminal voltage equivalent duty ratio, and sampling an output signal of the third operational amplifier to obtain an amplitude value of a terminal voltage; calculating the actual equivalent terminal voltage output by the inverter; calculating phase voltage output by the inverter; repeating the steps (3) to (4) in each control period of the motor simulator to obtain the actually output phase voltage; subtracting the actual equivalent terminal voltage from the command terminal voltage to obtain a compensation voltage; converting the compensation voltage into a two-phase coordinate system; feeding forward the compensation voltage to complete voltage compensation; the invention is simple and reliable, has high precision, and can improve the simulation precision of the motor simulator.
Description
Technical Field
The invention relates to a method for acquiring and compensating the voltage of the output end of a power level motor simulator inverter for testing a motor driver, in particular to a simple and reliable terminal voltage acquisition and compensation method which has high precision and can improve the simulation precision of a motor simulator and improve the precision of the power level motor simulator.
Background
As known, the power level motor simulator has the advantages of convenience in testing, capability of feeding energy back to a power grid, capability of simulating extreme or wrong working conditions of a motor and the like, and is widely applied to testing of motor drivers in the fields of electric automobiles, aerospace, wind power generation and the like. Testing of motor drives using DSP-based power stage motor simulators instead of traditional motor benches is a low cost, simple and effective way. However, since the DSP has a slow operation speed, there is an error in acquiring the terminal voltage output from the inverter in the motor driver, which leads to a decrease in the simulation accuracy of the motor simulator. In addition, the inverters in the motor driver and the motor simulator have non-ideal characteristics such as dead zone and voltage drop, which causes the voltage and current output by the inverter to be distorted, which also causes the simulation accuracy of the motor simulator to be reduced.
In order to improve the sampling precision of the voltage at the end of the inverter, the existing research proposes to use an integrator to acquire an equivalent value of the voltage at the end in a PWM period as the voltage at the current moment. It is also studied to realize accurate sampling of terminal voltage by using a high-speed ADC chip, but this method is generally used in an FPGA-based motor simulator, and the cost of the whole system is relatively high. The influence of the non-ideal characteristics of the inverter on the simulation accuracy of the motor simulator is generally eliminated by adopting a voltage compensation method. The existing voltage compensation strategies need to judge the current polarity and calculate the compensation voltage through a complex algorithm, and the calculated compensation voltage usually takes the voltage drop of the IGBT and the diode as a fixed value, so that the compensation is not accurate.
Disclosure of Invention
The invention aims to provide a terminal voltage acquisition and compensation method which is simple, reliable and high in precision and can improve the precision of a power-level motor simulator.
The technical scheme adopted by the invention is as follows:
a terminal voltage acquisition and compensation method for improving the precision of a power-stage motor simulator is characterized by comprising the following steps:
(1) respectively building terminal voltage acquisition circuits on two sides of a motor driver and a motor simulator; the terminal voltage acquisition circuit comprises a resistor voltage divider, a first operational amplifier, a second operational amplifier, a third operational amplifier and a DSP, wherein the output end of the resistor voltage divider is connected with the homodromous input ends of the first operational amplifier and the second operational amplifier; the reverse input end of the first operational amplifier is connected with the reference voltage 1, and the output end of the first operational amplifier is connected with the capture module of the DSP; the reverse input end of the second operational amplifier is connected with the output end through a resistor R1, and the output end of the second operational amplifier is connected with the third operational amplifier through a resistor R2; the in-phase end of the third operational amplifier is connected with the reference voltage 3, the inverting end of the third operational amplifier is connected with the output end of the third operational amplifier through a resistor R3, and the output end of the third operational amplifier is connected with an ADC module of the DSP;
(2) capturing an output signal of the first operational amplifier through a capture module of the DSP to obtain an equivalent duty ratio of one period of the terminal voltage, and sampling an output signal of the third operational amplifier through an ADC module of the DSP to obtain amplitudes of a high level and a low level of the terminal voltage;
(3) calculating the actual equivalent terminal voltage output by the inverter in one period according to the expression (1) by using the duty ratio and the amplitude obtained in the step (2);
(4) calculating the phase voltage output by the inverter according to an expression (2) by using the equivalent terminal voltage obtained in the step (3);
(5) repeating the steps (3) to (4) in each control period of the motor simulator, and obtaining the phase voltage actually output by the inverter of the motor driver in real time;
(6) subtracting the actual equivalent terminal voltage obtained in the step (3) from the command terminal voltage of the inverter to obtain a compensation voltage in a period;
(7) performing CLARK transformation on the compensation voltage obtained in the step (6) to obtain the compensation voltage under a two-phase coordinate system;
(8) feeding the two-phase compensation voltage obtained in the step (7) forward to an instruction phase voltage of the inverter to complete voltage compensation;
(9) repeating the steps (6) to (8) every control period of the motor driver to complete voltage compensation of an inverter in the motor driver;
(10) and (4) repeating the steps (6) to (8) every control cycle of the motor simulator to complete the voltage compensation of the inverter in the motor simulator.
The expression (1) in the step (3) is as follows:
Uterm＝UH·Duty+UL·(1-Duty) (1)
in the formula: u shapetermIs the equivalent terminal voltage; u shapeHAmplitude that is the terminal voltage high level; u shapeLThe amplitude of the low level of the terminal voltage; duty is the equivalent Duty cycle of the terminal voltage;
the expression (2) in the step (4) is as follows:
in the formula: u shapeAIs the A-phase voltage, U, of the inverter outputAterm、UBterm、UCtermRespectively, the inverter A is equal to the effective terminal voltage, the inverter B is equal to the effective terminal voltage, and the inverter C is equal to the effective terminal voltage; the same holds true for B, C phase voltage.
According to the voltage sampling range (0-3V) of an ADC module in the DSP and the precision (5 per mill) of a voltage dividing resistor, a chip resistor is selected as a resistor voltage divider in a terminal voltage acquisition circuit.
The first operational amplifier is used as a voltage comparator, a high-speed operational amplifier with the response time lower than 20ns is selected, and the reference voltage 1 is set to be 1/2 of the terminal voltage after voltage division.
The second operational amplifier is used as a voltage follower and the third operational amplifier is used as a voltage amplifier, and high-speed low-noise operational amplifiers with the bandwidth not less than 50MHz and the total harmonic distortion not more than-50 dBc are selected and used, and positive and negative double power supplies with the ripple not more than 10mV are needed for power supply. The resistors R1, R2 and R3 are selected according to recommended values of an operational amplifier manual, and the value of the reference voltage 3 is set according to the voltage sampling range (0-3V) of an ADC module in the DSP.
The invention provides a sampling method which accurately obtains the duty ratio and the amplitude of the voltage of an inverter terminal, and the voltage and current distortion of a motor simulator is caused by the change of the two aspects; the voltage compensation strategy is based on hardware to measure the terminal voltage in real time, the current polarity does not need to be judged through a complex algorithm, the compensation voltage is not needed to be calculated, and the compensation process is simpler and more reliable. Meanwhile, the current and temperature conduction voltage drop of the IGBT and the diode is taken into consideration, so that the method is simpler and the supplementary data is accurate.
Drawings
Fig. 1 is a designed terminal voltage acquisition circuit, in which the serial number 1 is a resistor divider, the serial number 2 is a first operational amplifier, the serial number 3 is a capture module of a DSP, the serial number 4 is a DSP (for calculation of equivalent terminal voltage), the serial number 5 is an ADC acquisition module of the DSP, the serial number 6 is a third operational amplifier, and the serial number 7 is a second operational amplifier.
Fig. 2 is a terminal voltage equivalent duty cycle acquisition principle.
Fig. 3 is a waveform of measured inverter terminal voltage and current.
Fig. 4 is a terminal voltage magnitude sampling principle.
Fig. 5 is a terminal voltage waveform and output signals of the first and third operational amplifiers.
Fig. 6 is a terminal voltage command duty ratio and an actually collected duty ratio and a duty ratio error.
Fig. 7(a) is a terminal voltage and current waveform when the terminal voltage is at a high level; fig. 7(b) is a waveform of the terminal voltage and the current when the terminal voltage is at a low level.
Fig. 8 is a comparison of inverter commanded phase voltages and collected actual output phase voltages and voltage errors.
Fig. 9 is the output voltage of the motor drive and the current simulated by the motor simulator before voltage compensation.
Fig. 10 is a comparison of current waveforms of a motor simulator before voltage compensation and a real motor under the same V/f control.
Fig. 11 is a comparison of inverter command phase voltages and actual output phase voltages in a voltage compensated front motor simulator and voltage errors.
Fig. 12 is a comparison of inverter commanded phase voltages and actual output phase voltages in a voltage compensated motor drive.
Fig. 13 is a comparison of inverter command phase voltages and actual output phase voltages in the voltage compensated motor simulator, along with voltage errors.
FIG. 14 is an FFT analysis and the effect of voltage compensation on the current waveform simulated by the motor simulator: in fig. 14, (a) shows that the inverter output voltages of the motor simulator and the motor driver are not voltage-compensated, while, (b) shows that only the inverter output voltage of the motor driver is voltage-compensated, and (c) shows that both the inverter output voltages of the motor simulator and the motor driver are voltage-compensated.
Fig. 15 is a comparison of current waveforms of a motor simulator and a real motor which is also voltage compensated.
Detailed Description
Table 1 shows the system parameters of the DSP-based power stage motor simulator in the experiment.
Table 2 is the basic parameters of the motor to be simulated by the motor simulator.
A terminal voltage acquisition and compensation method for improving the precision of a power-stage motor simulator is characterized by comprising the following steps:
(1) terminal voltage acquisition circuits are respectively built on two sides of the motor driver and the motor simulator, and the terminal voltage acquisition circuits are respectively connected with the output end of the motor driver and the input end and the output end of the motor simulator and are used for acquiring the terminal voltages of the output end (or the input end) of the motor driver and the output end (or the input end) of the motor simulator. The terminal voltage acquisition circuit comprises a resistor divider 1, a first operational amplifier 2, a second operational amplifier 7, a third operational amplifier 3 and a DSP4, wherein the output end of the resistor divider 1 is connected with the homodromous input end of the first operational amplifier 2 and the second operational amplifier 7; the inverting input terminal of the first operational amplifier 2 is connected to the reference voltage 1, and the output terminal is connected to the capture module 3 of the DSP 4. The inverting input terminal of the second operational amplifier 7 is connected to the output terminal via a resistor R1, and the output terminal is connected to the third operational amplifier 6 via a resistor R2. The in-phase end of the third operational amplifier 6 is connected with the reference voltage 3, the inverting end is connected with the output end through a resistor R3, and the output end is connected with the ADC module 5 of the DSP.
(2) According to the voltage sampling range (0-3V) of an ADC module 5 in the DSP and the precision (5 per mill) of a divider resistor, a chip resistor is selected as a resistor divider 1 in the terminal voltage acquisition circuit.
(3) The first operational amplifier is used as a voltage comparator, a high-speed operational amplifier with the response time lower than 20ns is selected, and the reference voltage 1 is set to be 1/2 of the terminal voltage after voltage division.
(4) The second operational amplifier is used as a voltage follower and the third operational amplifier is used as a voltage amplifier, and high-speed low-noise operational amplifiers with the bandwidth not less than 50MHz and the total harmonic distortion not more than-50 dBc are selected and used, and positive and negative double power supplies with the ripple not more than 10mV are needed for power supply. The resistors R1, R2 and R3 are selected according to recommended values of an operational amplifier manual, and the value of the reference voltage 3 is set according to the voltage sampling range (0-3V) of an ADC module in the DSP.
(5) The output signal of the first operational amplifier 2 is captured through a capture module of the DSP to obtain an equivalent duty ratio of one period of the terminal voltage, and the output signal of the third operational amplifier 6 is sampled through an ADC module of the DSP to obtain amplitudes of a high level and a low level of the terminal voltage.
(6) And (5) calculating the actual equivalent terminal voltage output by the inverter in one period according to the expression (1) by using the duty ratio and the amplitude obtained in the step (5).
(7) And (4) calculating the phase voltage output by the inverter according to an expression (2) by using the equivalent terminal voltage obtained in the step (6).
(8) And (5) repeating the steps (6) to (7) every control period of the motor simulator to obtain the phase voltage actually output by the inverter of the motor driver in real time.
(9) And (4) subtracting the actual equivalent terminal voltage obtained in the step (6) from the command terminal voltage of the inverter to obtain a compensation voltage in one period.
(10) Performing CLARK transformation on the compensation voltage calculated in the step (9) to obtain the compensation voltage under a two-phase coordinate system.
(11) And (4) feeding the two-phase compensation voltage obtained in the step (10) forward to the command phase voltage of the inverter to complete voltage compensation.
(12) And (5) repeating the steps (9) to (11) every control cycle of the motor driver to complete the voltage compensation of the inverter in the motor driver.
(13) And (5) repeating the steps (9) to (11) every control cycle of the motor simulator to complete the voltage compensation of the inverter in the motor simulator.
The expression in step 6 is as follows:
Uterm＝UH·Duty+UL·(1-Duty) (1)
in the formula: u shapetermFor equivalent terminal voltage, UHAmplitude of high level of terminal voltage, ULThe amplitude of the low level of the terminal voltage is shown, and the Duty is the equivalent Duty ratio of the terminal voltage.
The expression described in step 7 is as follows:
in the formula: u shapeAThe voltage is the A phase voltage output by the inverter, and the B, C phase voltage can be obtained by the same method. U shapeAterm、UBterm、UCtermThe voltage of the inverter A is equal to the voltage of the equivalent terminal, the voltage of the inverter B is equal to the voltage of the equivalent terminal, and the voltage of the inverter C is equal to the voltage of the equivalent terminal.
The theory of the invention is as follows:
(1) the principle of collecting the duty ratio and the amplitude of the voltage of the inverter terminal is as follows:
duty cycle acquisition principle:
the terminal voltage is divided and then is used as the input of a first operational amplifier with reference voltage 1, the first operational amplifier outputs a square wave signal with the same duty ratio as the terminal voltage after comparison, and the signal is collected by a DSP capture module to obtain the duty ratio of the terminal voltage. It should be noted that, when the current is relatively small, the edge of the voltage at the output end of the inverter is not a step rise or a step fall, but a slow rise or fall due to the influence of the parasitic capacitance of the IGBT. According to the volt-second balance principle, reference voltage 1 can be set to 1/2 of the divided terminal voltage to obtain the equivalent duty ratio of the terminal voltage, and the principle is shown in fig. 2.
Amplitude sampling principle:
fig. 3 shows measured waveforms of the inverter terminal voltage and current, and it can be seen that the amplitude is not constant when the terminal voltage is at a low level. When the current is not less than 0, the terminal voltage is a negative value, when the current is less than 0, the terminal voltage is a positive value, and the amplitude changes along with the current. This phenomenon is caused by the conduction voltage drop of the IGBT and the diode in the inverter, which varies with the magnitude of the current and the temperature. It is because the terminal voltage has a negative value, and thus the terminal voltage after voltage division cannot be directly sampled using the ADC. The second operational amplifier is used as a voltage follower to realize impedance matching, so that the interference to an original signal is minimum when ADC sampling is realized, and the quality of a sampled signal is high. The third operational amplifier is used for translating and scaling the terminal voltage after voltage division so that the terminal voltage is within a sampling range of the ADC module, R3/R2 is a voltage scaling multiple, and R3/R2 are equal to 1 in the invention because the terminal voltage is divided. It should be noted that the optimal acquisition time of the ADC within one period of the terminal voltage is the midpoint of the high level and the low level, respectively, where sampling can avoid the influence of on/off of other phase IGBTs. The ADC channel can be triggered by PWM modulating the present phase voltage at the period value and 0 value to achieve midpoint sampling. The principle of sampling the terminal voltage amplitude is shown in fig. 4.
Fig. 5 is a terminal voltage waveform, an output signal of the first op-amp, and an output signal of the third op-amp, as intercepted from an oscilloscope. Burrs in a dotted line rectangular frame in the figure are interference caused by the on and off of the IGBTs of the other two phases of the inverter on the voltage of the phase, and belong to a normal phenomenon. The interference is distributed on two sides of an ADC sampling point and is divided by resistors, so that the acquisition of terminal voltage is not influenced. Accurate terminal voltage equivalent duty ratio and amplitude can be obtained through a capture module and an ADC module of the DSP.
(2) Inverter voltage compensation principle:
the non-ideal characteristics of the inverter, such as dead time and the conduction voltage drop of the IGBT and the diode, change the duty ratio and amplitude of the terminal voltage output by the inverter compared with the command voltage, cause the voltage and current of the motor simulator to be distorted, and reduce the simulation precision.
The invention provides a sampling method which can accurately obtain the duty ratio and the amplitude of the voltage of an inverter terminal, and the voltage and current distortion of a motor simulator is caused by the change of the two aspects. Therefore, the invention provides a simpler and more accurate voltage compensation strategy by utilizing the obtained duty ratio and amplitude of the terminal voltage.
The difference between the commanded and measured terminal voltage equivalents may be written as:
ΔU＝Duty*·Udc-Uterm(3)
wherein, Δ U is the output voltage error, Duty is the command Duty cycle, UdcIs the inverter bus voltage.
Converting the three-phase voltage error into a two-phase coordinate system through CLARK conversion, and feeding forward to command two-phase voltage to complete voltage compensation, wherein the conversion formula is as follows:
the voltage compensation strategy provided by the invention is based on hardware to measure the terminal voltage in real time, the current polarity does not need to be judged through a complex algorithm and the compensation voltage does not need to be calculated, and the compensation process is simpler and more reliable. Meanwhile, the current and temperature conduction voltage drop of the IGBT and the diode is taken into consideration, and the compensation is more accurate.
Experiments that can demonstrate the effectiveness of the method of the invention are as follows, with the experimental platform parameters shown in tables 1 and 2.
1. Inverter terminal voltage acquisition result analysis
The terminal voltage acquisition circuit provided by the invention acquires the duty ratio and amplitude of the terminal voltage through the DSP and calculates the phase voltage.
Fig. 6 shows the command duty cycle of the voltage at the a-phase terminal read from the DSP and the actually acquired waveform of the equivalent duty cycle, and the difference between the two. It can be seen that the main source of the duty error is the inserted dead time, and the influence of the on-off delay of the IGBT, the transmission delay of the PWM command signal, and the parasitic capacitance at the time of the small current on the equivalent duty ratio also causes the fluctuation of the duty error.
FIG. 7 shows the voltage and current waveforms, U, at the A-phase terminal collected by the ADC moduleAHD、UAHF、UALD、UALFThe IGBT and the diode of the upper and lower bridge arms of the inverter are respectively connected with the voltage drop. The waveform coincidence between fig. 7(b) and the measured waveform of fig. 3 proves the correctness of the terminal voltage acquisition principle. It can be seen that the IGBT and diode turn-on voltage drops are not constant.
Fig. 8 shows the a-phase command voltage and the actual phase voltage calculated according to equations (1) and (2), and the difference therebetween. Fig. 8 shows that the non-ideal characteristics of the inverter can cause errors between the actual output voltage and the command voltage, and further cause current distortion.
2. Analysis of motor simulator experimental results before voltage compensation
In the motor simulator experiment, a motor model runs in a no-load mode, a motor driver adopts a V/f open-loop control strategy, and sine wave command voltage which is constant at 8V/10Hz is output.
In fig. 9, the upper graph shows the waveform of the a-phase voltage obtained from the DSP, and the lower graph shows the comparison between the reference current calculated by the motor model and the waveform of the actual output current of the motor simulator. Fig. 9 illustrates that the motor simulator can operate stably, and the actual current can accurately track the command current, but it cannot be proved that the motor simulator can accurately simulate the characteristics of the actual motor. Fig. 10 is a comparison of the current of the motor simulator with the current waveform of a real motor under the same V/f control, from which it can be found that the two are very identical in phase but different in shape, which is reflected in that the zero-crossing distortion time of the current of the motor simulator becomes longer and the amplitude changes.
By analysis, the current distortion is the root cause of the error of the current of the motor simulator, and the current distortion is caused by the voltage distortion caused by the non-ideal characteristics of the inverter in the motor driver and the motor simulator. Fig. 11 shows the command phase voltage and the actual output phase voltage of the inverter in the motor simulator and the difference therebetween, and it can be seen that there is a significant distortion in the output voltage. The same distortion also occurs in the inverter output voltage of the motor drive in fig. 9. The solution to this problem is to compensate the inverter output voltage.
3. Analysis of motor simulator experimental results after voltage compensation
Fig. 12 is a comparison of waveforms of the command voltage and the actual voltage after the inverter of the motor drive is compensated, and the inverter output voltage distortion is almost eliminated. Fig. 13 is a voltage comparison after voltage compensation of the inverter of the motor simulator, and the voltage error is already very small. Since the distortion of the output voltage of the motor driver disappears, the inverter command voltage of the motor simulator has better sine degree compared with that of fig. 11, and the fluctuation of the output voltage after compensation is caused by the closed-loop regulation of the system.
The current waveform and FFT analysis of the motor simulator without voltage compensation are shown in fig. 14(a), and the current distortion is severe and the THD value is large. As shown in fig. 14(b), when only the inverter output voltage of the motor driver is compensated, the current waveform distortion is reduced and the THD value is significantly reduced. As shown in fig. 14(c), the current waveforms of the inverter output voltages of the motor driver and the motor simulator after compensation are almost free from current distortion, and the THD value is only 2.27%. It can be seen that the compensation strategy proposed by the present invention can realize accurate voltage compensation.
Fig. 15 is a comparison of current waveforms of the motor simulator and a real motor after voltage compensation, where the phases and shapes of the two are almost the same, and it is proved that the terminal voltage acquisition method and the voltage compensation strategy based on the method can improve the simulation accuracy of the power-stage motor simulator.
TABLE 1 Motor simulator System parameters
Table 2 simulated motor parameters
Claims (5)
1. A terminal voltage acquisition and compensation method for improving the precision of a power-stage motor simulator is characterized by comprising the following steps:
(1) respectively building terminal voltage acquisition circuits on two sides of a motor driver and a motor simulator; the terminal voltage acquisition circuit comprises a resistor voltage divider, a first operational amplifier, a second operational amplifier, a third operational amplifier and a DSP, wherein the output end of the resistor voltage divider is connected with the homodromous input ends of the first operational amplifier and the second operational amplifier; the reverse input end of the first operational amplifier is connected with the reference voltage 1, and the output end of the first operational amplifier is connected with the capture module of the DSP; the reverse input end of the second operational amplifier is connected with the output end through a resistor R1, and the output end of the second operational amplifier is connected with the third operational amplifier through a resistor R2; the in-phase end of the third operational amplifier is connected with the reference voltage 3, the inverting end of the third operational amplifier is connected with the output end of the third operational amplifier through a resistor R3, and the output end of the third operational amplifier is connected with an ADC module of the DSP;
(2) capturing an output signal of the first operational amplifier through a capture module of the DSP to obtain an equivalent duty ratio of one period of the terminal voltage, and sampling an output signal of the third operational amplifier through an ADC module of the DSP to obtain amplitudes of a high level and a low level of the terminal voltage;
(3) calculating the actual equivalent terminal voltage output by the inverter in one period according to the expression (1) by using the duty ratio and the amplitude obtained in the step (2);
(4) calculating the phase voltage output by the inverter according to an expression (2) by using the equivalent terminal voltage obtained in the step (3);
(5) repeating the steps (3) to (4) in each control period of the motor simulator, and obtaining the phase voltage actually output by the inverter of the motor driver in real time;
(6) subtracting the actual equivalent terminal voltage obtained in the step (3) from the command terminal voltage of the inverter to obtain a compensation voltage in a period;
(7) performing CLARK transformation on the compensation voltage obtained in the step (6) to obtain the compensation voltage under a two-phase coordinate system;
(8) feeding the two-phase compensation voltage obtained in the step (7) forward to an instruction phase voltage of the inverter to complete voltage compensation;
(9) repeating the steps (6) to (8) every control period of the motor driver to complete voltage compensation of an inverter in the motor driver;
(10) repeating the steps (6) to (8) every control period of the motor simulator to complete voltage compensation of an inverter in the motor simulator;
the expression (1) in the step (3) is as follows:
Uterm＝UH·Duty+UL·(1-Duty) (1)
in the formula: u shapetermIs the equivalent terminal voltage; u shapeHAmplitude that is the terminal voltage high level; u shapeLThe amplitude of the low level of the terminal voltage; duty is the equivalent Duty cycle of the terminal voltage;
the expression (2) in the step (4) is as follows:
in the formula: u shapeAIs the A-phase voltage, U, of the inverter outputAterm、UBterm、UCtermRespectively, the inverter A is equal to the effective terminal voltage, the inverter B is equal to the effective terminal voltage, and the inverter C is equal to the effective terminal voltage; the same holds true for B, C phase voltage.
2. The method of claim 1, wherein a chip resistor is selected as a resistor divider in the terminal voltage acquisition circuit according to the voltage sampling range of the ADC module in the DSP and the precision of the divider resistor.
3. The method as claimed in claim 1, wherein the first operational amplifier is a high speed operational amplifier with response time less than 20ns, and the reference voltage 1 is 1/2 of the divided terminal voltage.
4. The method of claim 1, wherein the second operational amplifier is used as a voltage follower and the third operational amplifier is used as a voltage amplifier, the second operational amplifier and the third operational amplifier are high-speed low-noise operational amplifiers with a bandwidth of not less than 50MHz and a total harmonic distortion of not more than-50 dBc, and positive and negative double power supplies with a ripple of not more than 10mV are required.
5. The terminal voltage collecting and compensating method for improving the accuracy of a power-stage motor simulator as defined in claim 1, wherein the resistors R1, R2 and R3 are selected according to recommended values of an operational amplifier manual, and the reference voltage 3 is set according to a voltage sampling range of an ADC module in the DSP.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910914335.7A CN110716082B (en) | 2019-09-24 | 2019-09-24 | Terminal voltage acquisition and compensation method for improving precision of power-stage motor simulator |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910914335.7A CN110716082B (en) | 2019-09-24 | 2019-09-24 | Terminal voltage acquisition and compensation method for improving precision of power-stage motor simulator |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110716082A true CN110716082A (en) | 2020-01-21 |
| CN110716082B CN110716082B (en) | 2021-11-02 |
Family
ID=69210930
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910914335.7A Active CN110716082B (en) | 2019-09-24 | 2019-09-24 | Terminal voltage acquisition and compensation method for improving precision of power-stage motor simulator |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110716082B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112398107A (en) * | 2020-11-13 | 2021-02-23 | 陕西航空电气有限责任公司 | Voltage sampling circuit in overvoltage suppression device of three-phase variable-frequency alternating-current power generation system |
| CN113193801A (en) * | 2021-04-20 | 2021-07-30 | 华中科技大学 | High-speed motor simulator control system and high-speed motor simulator |
Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001078494A (en) * | 1999-09-06 | 2001-03-23 | Yaskawa Electric Corp | Method of correcting dc offset of ac motor driver |
| CN103888005A (en) * | 2012-12-21 | 2014-06-25 | 上海大郡动力控制技术有限公司 | Compensation voltage algorithm of inverter dead zone in motor control system and interpolation method |
| CN104091485A (en) * | 2014-04-11 | 2014-10-08 | 中北大学 | Load simulator driven by two motors |
| CN204347120U (en) * | 2014-12-24 | 2015-05-20 | 徐工集团工程机械股份有限公司 | Voltage measuring apparatus |
| CN107017796A (en) * | 2017-06-12 | 2017-08-04 | 湖南大学 | A kind of orthogonal inverter control method of two-phase with compensation of delay function |
| CN206557603U (en) * | 2017-03-20 | 2017-10-13 | 北京润科通用技术有限公司 | A kind of motor simulation device and power of motor level emulation test system |
| CN107565873A (en) * | 2017-09-30 | 2018-01-09 | 广东威灵电机制造有限公司 | The terminal voltage measurement apparatus and measuring method of motor |
| CN107896054A (en) * | 2017-11-28 | 2018-04-10 | 株洲易力达机电有限公司 | A kind of EPS brushless electric machines PWM ripple dead area compensation devices |
| CN108092532A (en) * | 2017-12-31 | 2018-05-29 | 王大方 | A kind of Inverter Dead-time compensation method based on PWM triggering end voltage samples |
| CN108982959A (en) * | 2018-08-01 | 2018-12-11 | 上海金脉电子科技有限公司 | Motor control three-phase voltage sample circuit |
| CN109687701A (en) * | 2017-10-19 | 2019-04-26 | 华晨汽车集团控股有限公司 | A kind of identification of electric machine controller dead zone and compensation method |
| KR20190075621A (en) * | 2017-12-21 | 2019-07-01 | 엘지전자 주식회사 | Power converting apparatus and air conditioner including the same |
| CN110034700A (en) * | 2018-01-12 | 2019-07-19 | 欧姆龙(上海)有限公司 | The waveform controlling method of inverter output current, device and system |
| CN110048606A (en) * | 2019-05-23 | 2019-07-23 | 哈尔滨工业大学 | DC-DC boost converter Dynamic sliding mode voltage control method based on two type Adaptive Fuzzy Neural-network of section |
-
2019
- 2019-09-24 CN CN201910914335.7A patent/CN110716082B/en active Active
Patent Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001078494A (en) * | 1999-09-06 | 2001-03-23 | Yaskawa Electric Corp | Method of correcting dc offset of ac motor driver |
| CN103888005A (en) * | 2012-12-21 | 2014-06-25 | 上海大郡动力控制技术有限公司 | Compensation voltage algorithm of inverter dead zone in motor control system and interpolation method |
| CN104091485A (en) * | 2014-04-11 | 2014-10-08 | 中北大学 | Load simulator driven by two motors |
| CN204347120U (en) * | 2014-12-24 | 2015-05-20 | 徐工集团工程机械股份有限公司 | Voltage measuring apparatus |
| CN206557603U (en) * | 2017-03-20 | 2017-10-13 | 北京润科通用技术有限公司 | A kind of motor simulation device and power of motor level emulation test system |
| CN107017796A (en) * | 2017-06-12 | 2017-08-04 | 湖南大学 | A kind of orthogonal inverter control method of two-phase with compensation of delay function |
| CN107565873A (en) * | 2017-09-30 | 2018-01-09 | 广东威灵电机制造有限公司 | The terminal voltage measurement apparatus and measuring method of motor |
| CN109687701A (en) * | 2017-10-19 | 2019-04-26 | 华晨汽车集团控股有限公司 | A kind of identification of electric machine controller dead zone and compensation method |
| CN107896054A (en) * | 2017-11-28 | 2018-04-10 | 株洲易力达机电有限公司 | A kind of EPS brushless electric machines PWM ripple dead area compensation devices |
| KR20190075621A (en) * | 2017-12-21 | 2019-07-01 | 엘지전자 주식회사 | Power converting apparatus and air conditioner including the same |
| CN108092532A (en) * | 2017-12-31 | 2018-05-29 | 王大方 | A kind of Inverter Dead-time compensation method based on PWM triggering end voltage samples |
| CN110034700A (en) * | 2018-01-12 | 2019-07-19 | 欧姆龙(上海)有限公司 | The waveform controlling method of inverter output current, device and system |
| CN108982959A (en) * | 2018-08-01 | 2018-12-11 | 上海金脉电子科技有限公司 | Motor control three-phase voltage sample circuit |
| CN110048606A (en) * | 2019-05-23 | 2019-07-23 | 哈尔滨工业大学 | DC-DC boost converter Dynamic sliding mode voltage control method based on two type Adaptive Fuzzy Neural-network of section |
Non-Patent Citations (6)
| Title |
|---|
| DAFANG WANG ETC.: "Influences on Output Distortion in Voltage Source Inverter Caused by Power Devices’ Parasitic Capacitance", 《IEEE TRANSACTIONS ON POWER ELECTRONICS》 * |
| LIU GANG ETC.: "Neutral-Point Voltage Balancing in Three-Level Inverters Using an Optimized Virtual Space Vector PWM With Reduced Commutations", 《IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS》 * |
| MINGYU WANG ETC.: "A Novel Method for Compensating Phase Voltage Based on Online Calculating Compensation Time", 《JOURNAL OF POWER ELECTRONICS》 * |
| 汪苗等: "基于积分复位的电机模拟器端口电压采样方法研究", 《电测与仪表》 * |
| 董光林: "基于等效端电压的车用电机模拟器电压补偿研究", 《中国优秀硕士学位论文全文数据库 工程科技Ⅱ辑》 * |
| 高玲玲: "伺服电机模拟器的设计与实现", 《电脑知识与技术》 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112398107A (en) * | 2020-11-13 | 2021-02-23 | 陕西航空电气有限责任公司 | Voltage sampling circuit in overvoltage suppression device of three-phase variable-frequency alternating-current power generation system |
| CN112398107B (en) * | 2020-11-13 | 2023-06-09 | 陕西航空电气有限责任公司 | Voltage sampling circuit in overvoltage suppression device of three-phase variable-frequency alternating-current power generation system |
| CN113193801A (en) * | 2021-04-20 | 2021-07-30 | 华中科技大学 | High-speed motor simulator control system and high-speed motor simulator |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110716082B (en) | 2021-11-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Monfared et al. | Direct active and reactive power control of single-phase grid-tie converters | |
| CN104953877B (en) | T-shaped three-level inverter finite aggregate model predictive control method and system | |
| CN110716082B (en) | Terminal voltage acquisition and compensation method for improving precision of power-stage motor simulator | |
| CN207021912U (en) | Multiple-channel output random waveform voltage source system | |
| Wang et al. | Online feedback dead time compensation strategy for three-level T-type inverters | |
| CN112072986B (en) | Accurate dead-zone compensation method for three-phase inverter and three-phase inverter | |
| CN104821601A (en) | Three-phase photovoltaic grid-connected inverter control device | |
| Wang et al. | Influences on output distortion in voltage source inverter caused by power devices’ parasitic capacitance | |
| CN110165922A (en) | Multiple-channel output random waveform power signal source | |
| CN105226985B (en) | Based on three equivalent level dead-zone compensation methods of current phasor | |
| CN108964119B (en) | Common-mode voltage estimation method for T-type three-level grid-connected inverter | |
| Abdalrahman et al. | Control of the grid-connected inverter using dsPIC microcontroller | |
| CN205004756U (en) | Control device of three -phase photovoltaic grid -connected inverter | |
| Fratta et al. | Modeling inverter losses for circuit simulation | |
| Xiao et al. | A novel current controller for grid-connected voltage-source-inverters | |
| CN112858802B (en) | Method, device and system for determining effective value of output electric parameter of switching power converter | |
| Kaviani et al. | A switching pattern for single-phase single-stage current source boost inverter | |
| CN109510548B (en) | Double-fed motor flexible power control method and device | |
| Wang et al. | A desktop electric machine emulator implementation method based on phase voltage reconstruction | |
| CN107817379B (en) | Boost inductor current detection system of rectifier | |
| CN209881674U (en) | Multi-output arbitrary waveform power signal source | |
| CN113241983B (en) | Dead zone compensation method and system for three-phase voltage source inverter | |
| CN209844854U (en) | Inversion test correction device applied to rectifier | |
| Raab et al. | Determination of RMS current load on the DC-link capacitor of voltage source converters using direct current control | |
| CN103023291A (en) | Resonance suppression method based on voltage-type grid-connected inverter |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |