CN107134951B - Intelligent voltage following braking device and control method thereof - Google Patents
Intelligent voltage following braking device and control method thereof Download PDFInfo
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- CN107134951B CN107134951B CN201710336215.4A CN201710336215A CN107134951B CN 107134951 B CN107134951 B CN 107134951B CN 201710336215 A CN201710336215 A CN 201710336215A CN 107134951 B CN107134951 B CN 107134951B
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- 238000000034 method Methods 0.000 title claims abstract description 19
- 230000003750 conditioning effect Effects 0.000 claims abstract description 7
- 238000005265 energy consumption Methods 0.000 claims abstract description 7
- 238000001914 filtration Methods 0.000 claims abstract description 7
- 238000002955 isolation Methods 0.000 claims abstract description 4
- 238000005070 sampling Methods 0.000 claims description 33
- 238000001514 detection method Methods 0.000 claims description 15
- 238000012360 testing method Methods 0.000 claims description 13
- 238000004891 communication Methods 0.000 claims description 12
- 238000012544 monitoring process Methods 0.000 claims description 6
- 238000010248 power generation Methods 0.000 claims description 6
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- 239000003990 capacitor Substances 0.000 description 2
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Classifications
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P3/00—Arrangements for stopping or slowing electric motors, generators, or dynamo-electric converters
- H02P3/06—Arrangements for stopping or slowing electric motors, generators, or dynamo-electric converters for stopping or slowing an individual dynamo-electric motor or dynamo-electric converter
- H02P3/18—Arrangements for stopping or slowing electric motors, generators, or dynamo-electric converters for stopping or slowing an individual dynamo-electric motor or dynamo-electric converter for stopping or slowing an ac motor
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/32—Means for protecting converters other than automatic disconnection
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P3/00—Arrangements for stopping or slowing electric motors, generators, or dynamo-electric converters
- H02P3/06—Arrangements for stopping or slowing electric motors, generators, or dynamo-electric converters for stopping or slowing an individual dynamo-electric motor or dynamo-electric converter
- H02P3/18—Arrangements for stopping or slowing electric motors, generators, or dynamo-electric converters for stopping or slowing an individual dynamo-electric motor or dynamo-electric converter for stopping or slowing an ac motor
- H02P3/22—Arrangements for stopping or slowing electric motors, generators, or dynamo-electric converters for stopping or slowing an individual dynamo-electric motor or dynamo-electric converter for stopping or slowing an ac motor by short-circuit or resistive braking
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/32—Means for protecting converters other than automatic disconnection
- H02M1/322—Means for rapidly discharging a capacitor of the converter for protecting electrical components or for preventing electrical shock
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Control Of Ac Motors In General (AREA)
- Electrostatic Separation (AREA)
Abstract
The invention discloses an intelligent voltage following braking device and a control method thereof, wherein the device comprises an isolation filtering module, a signal acquisition conditioning module, a braking main loop module and other components; the method comprises the steps of system fault judgment, judgment of the current state of the motor, double redundancy acquisition of the current voltage of the bus and the like. The invention can automatically adapt to the change of the bus voltage, realize the on-line automatic setting of the discharge voltage threshold, and consume redundant electric energy through the energy consumption resistor when the motor is braked, so as to prevent the bus voltage from rising suddenly in the braking process.
Description
Technical Field
The invention belongs to the technical field of power electronics, and particularly relates to an intelligent voltage following braking device and a control method thereof.
Background
Modern power electronics technology has grown in popularity, and inverters, servo drives, etc. have found wide application in motor traction systems, and are all equipped with braking systems. The power supply of the motor driving system is generally classified into two types, one type is constant voltage power supply, and the system is characterized in that the power supply voltage is constant and the voltage fluctuation is not large; another type is a battery-powered motor drive system, which is characterized by a gradual decrease in the voltage supplied due to the loss of battery energy, and only when the voltage of the battery drops to a certain extent, the drive stops, and the motor drive and motor can operate normally over this wide voltage range. In the two systems, the motor is switched between a motor state and a generator state, when the dragging system is in a driving state, the motor works in the motor state, electric energy flows to the motor from a power supply, when the dragging system is in a braking state, the motor works in the generator state, at the moment, the electric energy flows to the driver from the motor, the formed feedback current flows to the direct current bus through an absorption loop of a switching tube of the driver, the supporting capacitor of the bus is rapidly charged in a short time, the charge of the capacitor is rapidly increased, the voltage of the direct current bus is rapidly increased, and if the excessive electric energy is not timely released, the safety of a motor controller is extremely threatened, and even the motor controller is burnt.
At present, the energy-consumption braking technology with constant discharge voltage threshold is mature, but the technology has obvious limitations, mainly the discharge voltage threshold can not be flexibly adjusted according to the bus voltage, and the universality is poor. When the technology is applied to a variable-voltage power supply system, the protection voltage threshold value can only be determined according to the highest voltage, when the bus voltage drops more, the energy consumption braking device can not timely respond to the rapid rising of the bus voltage, the bus voltage can not be timely controlled at the current level of the energy consumption braking device, the rapid rising of the bus voltage can be caused, when the bus voltage rises to the original maximum value of the bus voltage, the discharge protection is started, the excessive electric energy is consumed, the bus voltage can be changed or cannot be protected in a large range in a short time, the safety of the system is possibly threatened, and the unstable operation of the system is caused. In addition, even if applied to a bus voltage fixing system, the variety of driving products is caused due to the variety of voltage values, which also makes the technology inflexible. Therefore, an intelligent voltage following braking device needs to be developed to solve the problem, and the intelligent voltage following braking device can automatically adapt to the change of the bus voltage, so that the on-line automatic setting of the discharge voltage threshold value is realized.
Disclosure of Invention
The invention aims to overcome the defects and provide an intelligent voltage following braking device and a control method thereof.
The invention discloses an intelligent voltage following braking device, which comprises:
the isolation filtering module is used for filtering interference in the power supply system and reducing the influence of strong interference conducted by the power supply on the device;
the bus voltage sampling module is used for monitoring bus voltage change in real time and providing basis for determining a discharge voltage threshold value;
the bus current sampling module is used for detecting the direction of bus current, determining whether the motor dragging system is in an electric state or a power generation state currently, providing a criterion for determining the current value of bus voltage, indicating that the system is in the electric state when the current positively flows, indicating that the collected bus voltage can be used as the current value of the bus voltage, and indicating that the system is in the power generation state when the current negatively flows, wherein the voltage value cannot be used as the current value of the bus voltage;
the temperature sampling module is used for monitoring whether the brake main loop module is overheated or not in real time;
the signal acquisition conditioning module is used for converting and conditioning acquired signals and improving the acquisition precision;
the overvoltage protection module is used for executing a protection function when the system is in an overvoltage state;
the overcurrent protection module is used for executing a protection function when an overcurrent state occurs in the system;
the over-temperature protection module is used for executing a protection function when the system is in an over-temperature state;
the communication module is used for communicating with other modules of the system to read bus voltage and provide current state information of the device for the system;
the driving module is used for driving the braking main loop module;
the watchdog module is used for preventing the program from running off;
the central processing unit module is used for taking charge of the function realization of the whole system, including sampling, communication and fault logic judgment;
and the braking main loop module is used for realizing the consumption of redundant electric energy in the braking process through the energy consumption resistor.
The control method of the intelligent voltage following braking device comprises the following steps:
step 1: after the system is powered on, the watchdog module stops working and initializes the system;
step 2: after the necessary system configuration is completed, the watchdog is opened, communication with the driver is started, required information is read, and current, voltage and temperature physical quantity are collected;
step 3: judging whether the system has faults or not, and juxtaposing relevant flag bits;
step 4: judging whether the collected bus voltage is effective, determining the current value of the bus voltage under the condition of being effective, and calculating a discharge voltage threshold according to the current value of the bus voltage, thereby realizing real-time control of the bus voltage and preventing bus overvoltage.
The step 3 specifically comprises the following steps:
step 31: firstly judging whether the system has an overcurrent phenomenon, and if the system has the overcurrent phenomenon, carrying out overcurrent fault treatment; if the system does not have the overcurrent phenomenon, turning to the next step;
step 32: secondly, judging whether the system has overheat, and if so, performing overheat fault treatment; if the system does not have overheat, turning to the next step;
step 33: finally judging whether the system has overvoltage or undervoltage phenomenon, if the system has overvoltage or undervoltage phenomenon, carrying out overvoltage or undervoltage fault treatment; if the system does not have over-voltage or under-voltage, go to step 4.
The specific steps for acquiring the bus voltage in the steps are as follows:
step 41: the flow direction of the bus current determines whether a bus voltage sampling value is effective, when the current is positive, the motor state is indicated, the sampling value is effective, and when the current is negative, the generator state is indicated, and the sampling value is ineffective; if the current cannot be judged positive or negative, the busbar voltage sampling value is completely invalid;
step 42: under the condition that the current sampling value is positive, n busbar voltage values are continuously collected and are arranged from small to large to be V 1 ,V 2 ,V 3 ,…,V n The sample mean and standard deviation of the bus voltage are respectively:
the method for detecting and rejecting outliers of the collected busbar voltage samples by utilizing Grubbs criteria comprises the following steps:
step 421; calculating statistics:
step 422; determining the detection level alpha, and finding the corresponding critical value G of n and alpha in a Grubbs test critical value table 1-α (n);
Step 423; determining whether or not there is an outlier, when G n >G′ n And G is n >G 1-α (n) determination of V n Is an outlier; when G' n >G n And G' n >G 1-α (n), then determine V 1 Is an outlier; otherwise, judging that the outlier is not present;
step 424; after outliers are removed, the average value of the bus voltage is recalculated according to the residual bus voltage sampling values and is used as the current value of the bus voltage
Step 43: the bus voltage value detected by the driver read in a communication mode is detected and removed in an outlier mode to obtain the current value of the bus voltage
Step 44: if it isAnd->Is similar in value, indicating that the system is normal, +.>And->Taking the average after the addition of the values of (2) as the current bus voltage value +.>
Step 45: if it isAnd->The value difference of the bus voltage value is larger, so that the system has faults, and the current bus voltage value is also given as much as possible, thereby ensuring lower false alarm rate; if->The values of 5 times before and after are larger, which indicates +.>Problems may occur if +.>The values of the last 5 times differ little, in which case +.>The average value of the last few values is taken as the current bus voltage; if->The values of 5 times before and after are larger, which indicates +.>Problems may occur if +.>The values of the last 5 times are not very different, and +.>The average of the values of the last few times is taken as the current bus voltage;
step 46: if it isAnd->The values of (2) differ greatly and +.>The difference between the values of the two is larger before and after the system, which indicates that the system has serious faults; or->And->The values of (2) differ significantly, although +.>The difference between the front value and the rear value of 5 times is not large, which also indicates that the system has serious faults, and at the moment, alarm signals are sent out and the system is stopped.
Through the above stepsThe value of (2) determines the voltage value of the current bus bar +.>The discharge voltage threshold is calculated as: />
The invention can automatically adapt to the change of the bus voltage and realize the on-line automatic setting of the discharge voltage threshold.
Drawings
FIG. 1 is a schematic diagram of the intelligent voltage following brake device of the present invention.
Fig. 2 is a voltage-following energy-consuming brake control flow chart.
Fig. 3 is a bus voltage acquisition flow chart.
Detailed Description
The invention is further illustrated by the following examples:
as shown in fig. 1, an intelligent voltage following brake device of the present invention includes:
the isolation filtering module is used for filtering interference in the power supply system and reducing the influence of strong interference conducted by the power supply on the device;
the bus voltage sampling module is used for monitoring bus voltage change in real time and providing basis for determining a discharge voltage threshold value;
the bus current sampling module is used for detecting the direction of bus current, determining whether the motor dragging system is in an electric state or a power generation state currently, providing a criterion for determining the current value of bus voltage, indicating that the system is in the electric state when the current positively flows, indicating that the collected bus voltage can be used as the current value of the bus voltage, and indicating that the system is in the power generation state when the current negatively flows, wherein the voltage value cannot be used as the current value of the bus voltage;
the temperature sampling module is used for monitoring whether the brake main loop module is overheated or not in real time;
the signal acquisition conditioning module is used for converting and conditioning acquired signals and improving the acquisition precision;
the overvoltage protection module is used for executing a protection function when the system is in an overvoltage state;
the overcurrent protection module is used for executing a protection function when an overcurrent state occurs in the system;
the over-temperature protection module is used for executing a protection function when the system is in an over-temperature state;
the communication module is used for communicating with other modules of the system to read bus voltage and provide current state information of the device for the system;
the driving module is used for driving the braking main loop module;
the watchdog module is used for preventing the program from running off;
the central processing unit module is used for taking charge of the function realization of the whole system, including sampling, communication and fault logic judgment;
and the braking main loop module is used for realizing the consumption of redundant electric energy in the braking process through the energy consumption resistor.
The control method of the intelligent voltage following braking device comprises the following steps:
step 1: after the system is powered on, the watchdog module stops working and initializes the system;
step 2: after the necessary system configuration is completed, the watchdog is opened, communication with the driver is started, required information is read, and current, voltage and temperature physical quantity are collected;
step 3: judging whether the system has faults or not, and juxtaposing relevant flag bits;
step 4: judging whether the collected bus voltage is effective, determining the current value of the bus voltage under the condition of being effective, and calculating a discharge voltage threshold according to the current value of the bus voltage, thereby realizing real-time control of the bus voltage and preventing bus overvoltage.
The step 3 specifically comprises the following steps:
step 31: firstly judging whether the system has an overcurrent phenomenon, and if the system has the overcurrent phenomenon, carrying out overcurrent fault treatment; if the system does not have the overcurrent phenomenon, turning to the next step;
step 32: secondly, judging whether the system has overheat, and if so, performing overheat fault treatment; if the system does not have overheat, turning to the next step;
step 33: finally judging whether the system has overvoltage or undervoltage phenomenon, if the system has overvoltage or undervoltage phenomenon, carrying out overvoltage or undervoltage fault treatment; if the system does not have over-voltage or under-voltage, go to step 4.
The specific steps for acquiring the bus voltage in the steps are as follows:
step 41: the flow direction of the bus current determines whether a bus voltage sampling value is effective, when the current is positive, the motor state is indicated, the sampling value is effective, and when the current is negative, the generator state is indicated, and the sampling value is ineffective; if the current cannot be judged positive or negative, the busbar voltage sampling value is completely invalid;
step 42: under the condition that the current sampling value is positive, n busbar voltage values are continuously collected and are arranged from small to large to be V 1 ,V 2 ,V 3 ,…,V n The sample mean and standard deviation of the bus voltage are respectively:
the method for detecting and rejecting outliers of the collected busbar voltage samples by utilizing Grubbs criteria comprises the following steps:
step 421; calculating statistics:
step 422; determining the detection level alpha, and finding the corresponding critical value G of n and alpha in a Grubbs test critical value table 1-α (n);
Step 423; determining whether or not there is an outlier, when G n >G′ n And G is n >G 1-α (n) determination of V n Is an outlier; when G' n >G n And G' n >G 1-α (n), then determine V 1 Is an outlier; otherwise, judging that the outlier is not present;
step 424; after outliers are removed, the average value of the bus voltage is recalculated according to the residual bus voltage sampling values and is used as the current value of the bus voltage
Step 43: the bus voltage value detected by the driver read in a communication mode is detected and removed in an outlier mode to obtain the current value of the bus voltage
Step 44: if it isAnd->Is similar in value, indicating that the system is normal, +.>And->Taking the average after the addition of the values of (2) as the current bus voltage value +.>
Step 45: if it isAnd->The larger value of (2) indicates that the system has occurred and is thereforeThe barrier should also give the current bus voltage value as much as possible at the moment, so as to ensure lower false alarm rate; if->The values of 5 times before and after are larger, which indicates +.>Problems may occur if +.>The values of the last 5 times differ little, in which case +.>The average value of the last few values is taken as the current bus voltage; if->The values of 5 times before and after are larger, which indicates +.>Problems may occur if +.>The values of the last 5 times are not very different, and +.>The average of the values of the last few times is taken as the current bus voltage;
step 46: if it isAnd->The values of (2) differ greatly and +.>The two values are mutually similar in several timesThe difference is also larger, which indicates that the system has serious faults; or->And->The values of (2) differ significantly, although +.>The difference between the front value and the rear value of 5 times is not large, which also indicates that the system has serious faults, and at the moment, alarm signals are sent out and the system is stopped.
Through the above stepsThe value of (2) determines the voltage value of the current bus bar +.>The discharge voltage threshold is calculated as: />
As shown in fig. 2, after the system is powered on, the system is initialized first, after necessary system configuration is completed, communication with a driver is started, required information is read, physical quantities such as current, voltage and temperature are collected, whether the system is faulty or not is judged, then a main program is entered, whether the collected bus voltage is effective or not is judged, the current value of the bus voltage is determined under the condition that the collected bus voltage is effective, a discharge voltage threshold value is calculated according to the current value of the bus voltage, and therefore real-time control of the bus voltage is achieved, and bus overvoltage is prevented.
The main process of judging the effectiveness of the bus voltage and determining the current value is as follows:
the central processing unit module detects the bus current direction and judges whether the motor is in a motor state or a generator state in parallel by reading the driver information, so that the bus current direction and the generator state are respectively used as judging bases for bus voltage detection effectiveness and bus voltage effectiveness detected by the driver, if the motor is in the motor state, the sampling voltage value is effective, and otherwise, the sampling voltage value is ineffective. The current detection method is that the bus current sampling module detects the bus current direction so as to judge the working state of the motor, wherein the current is positive and is in the motor state, and the current is negative and is in the generator state; and reading the information of the driver through a driver judging method, and determining the current working state of the motor.
When the motor is determined to be in the motor state, n bus voltage values (organized into a first group) are collected and n bus voltage values (organized into a second group) of the drive are read, where n=10 is assumed. Analysis was performed in the following 5 cases:
case 1 (the difference between the current means of the two groups is small):
the first set of 10 voltage samples are:
381.5V,380V,383V,382.3V,379.8V,375V,379.1V,378V,385V,386.2V
the mean value of the set of data is:
the standard deviation is: s (V) = 3.1627V
Determining the detection level alpha=0.05, n=10, and finding the corresponding critical value G of n, alpha in the "Grubbs test critical value table 1-α (n) = 2.176, and G n max = 1.8939, then G n max <G 1-α (n), the set of data is outlier free.
The second set of 10 bus voltage values read by the driver is:
378V,382V,383.6V,382.1V,379.9V,376V,379.6V,377V,386V,381.2V
the mean value of the set of data is:
the standard deviation is: s (V) = 2.9166V
Determining the detection level alpha=0.05, n=10, and finding the corresponding critical value G of n, alpha in the "Grubbs test critical value table 1-α (n) = 2.176, and G n max = 1.8721, then G n max <G 1-α (n), the set of data is outlier free.
Then
Thereby, can obtain:
case 2 (the difference between the current means of the two groups is large, and the first group of near-several means meets the requirement, and the second group of near-several means does not meet the requirement):
the first set of 10 voltage samples are:
382V,380V,381.8V,382.5V,378.8V,376V,377.1V,379V,386V,384.2V
the mean value of the set of data is:
the standard deviation is: s (V) = 2.975V
Determining the detection level alpha=0.05, n=10, and finding the corresponding critical value G of n, alpha in the "Grubbs test critical value table 1-α (n) = 2.176, and G n max = 1.7681, then G n max <G 1-α (n), the set of data is outlier free.
The second set of 10 bus voltage values read by the driver is:
392.5V,389V,393V,392.3V,395.8V,394V,393.1V,394.2V,395V,396.2V
the mean value of the set of data is:
the standard deviation is: s (V) = 1.9664V
Determining the detection level alpha=0.05, n=10, and finding the corresponding critical value of n, alpha in the Grubbs' test critical value tableValue G 1-α (n) = 2.176, and G n max = 2.2935, then G n max >G 1-α (n), so the data set has outliers, 389V is outlier, and the mean is recalculated after outlier removal:
thenThe mean of the first group should be further compared to the mean of the second group by approximately 5 times.
The mean values of the first group of nearly 5 times are known to be:
382.01V,381.05V,380.74V,379.21V,380.74V,
wherein the maximum value is 382.01V, the minimum value is 379.21V, and the difference between the two values is |382.01-379.21 |=2.8 < 10V, so that the requirement is met.
The mean values of the second group of nearly 5 times are known to be:
394.01V,382.05V,385.17V,389.12V,383.16V,
wherein the maximum value is 394.01V, the minimum value is 382.05V, and the difference between the two values is |394.01-382.05 |=11.96 > 10V, which does not meet the requirement.
Thus taking the average of the first group of nearly 5 times, i.e. 382.01V,381.05V,380.74V,379.21V,380.74V, as the bus current voltage value, then
V m =380.75V,
Case 3 (the difference between the current means of the two groups is large, and the first group of near-several means does not meet the requirement, and the second group of near-several means meets the requirement):
the first set of 10 voltage samples are:
392.5V,389V,393V,392.3V,395.8V,394V,393.1V,394.2V,395V,396.2V
the mean value of the set of data is:
the standard deviation is: s (V) = 1.9664V
Determining the detection level alpha=0.05, n=10, and finding the corresponding critical value G of n, alpha in the "Grubbs test critical value table 1-α (n) = 2.176, and G n max = 2.2935, then G n max >G 1-α (n), so the data set has outliers, 389V is outlier, and the mean is recalculated after outlier removal:
the second set of 10 bus voltage values read by the driver is:
382V,380V,381.8V,382.5V,378.8V,376V,377.1V,379V,386V,384.2V
the mean value of the set of data is:
the standard deviation is: s (V) = 2.975V
Determining the detection level alpha=0.05, n=10, and finding the corresponding critical value G of n, alpha in the "Grubbs test critical value table 1-α (n) = 2.176, and G n max = 1.7681, then G n max <G 1-α (n), the set of data is outlier free.
ThenThe mean of the first group should be further compared to the mean of the second group by approximately 5 times.
The mean values of the first group of nearly 5 times are known to be:
394.01V,382.05V,385.17V,389.12V,383.16V,
wherein the maximum value is 394.01V, the minimum value is 382.05V, and the difference between the two values is |382.01-379.21 |=11.96 > 10V, which does not meet the requirement.
The mean values of the second group of nearly 5 times are known to be:
382.01V,381.05V,380.74V,379.21V,380.74V,
wherein the maximum value is 382.01V, the minimum value is 379.21V, and the difference between the two values is |382.01-379.21 |=2.8 < 10V, so that the requirement is met.
Thus taking the average value of the second group of nearly 5 times, i.e. 382.01V,381.05V,380.74V,379.21V,380.74V, as the bus current voltage value, then
V m =380.75V,
Case 4 (the difference between the current means of the two groups is large, and the means of the two groups are not satisfied either):
the first set of 10 voltage samples are:
392.5V,389V,393V,392.3V,395.8V,394V,393.1V,394.2V,395V,396.2V
the mean value of the set of data is:
the standard deviation is: s (V) = 1.9664V
Determining the detection level alpha=0.05, n=10, and finding the corresponding critical value G of n, alpha in the "Grubbs test critical value table 1-α (n) = 2.176, and G n max = 2.2935, then G n max >G 1-α (n), so the data set has outliers, 389V is outlier, and the mean is recalculated after outlier removal:
the second set of 10 bus voltage values read by the driver is:
382V,380V,381.8V,382.5V,378.8V,376V,377.1V,379V,386V,384.2V
the mean value of the set of data is:
the standard deviation is: s (V) = 2.975V
Determining the detection level alpha=0.05, n=10, and finding the corresponding critical value G of n, alpha in the "Grubbs test critical value table 1-α (n) = 2.176, and G n max = 1.7681, then G n max <G 1-α (n), the set of data is outlier free.
ThenThe mean of the first group should be further compared to the mean of the second group by approximately 5 times.
The mean values of the first group of nearly 5 times are known to be:
394.01V,382.05V,385.17V,389.12V,383.16V,
wherein the maximum value is 394.01V, the minimum value is 382.05V, and the difference between the two values is |382.01-379.21 |=11.96 > 10V, which does not meet the requirement.
The mean values of the second group of nearly 5 times are known to be:
392.01V,381.05V,380.74V,379.21V,380.74V,
the maximum value is 392.01V, the minimum value is 379.21V, and the difference between the two values is 392.01-379.21 |=12.8 > 10V, which does not meet the requirement.
Therefore, both groups do not meet the requirements, and the alarm is stopped.
Case 5 (the difference between the current means of the two groups is large, but the near few means of the two groups meet the requirement):
the first set of 10 voltage samples are:
392.5V,389V,393V,392.3V,395.8V,394V,393.1V,394.2V,395V,396.2V
the mean value of the set of data is:
the standard deviation is: s (V) = 1.9664V
Determining the detection level alpha=0.05, n=10, and finding the corresponding n, alpha in the Grubbs' test threshold value tableCritical value G of (2) 1-α (n) = 2.176, and G n max = 2.2935, then G n max >G 1-α (n), so the data set has outliers, 389V is outlier, and the mean is recalculated after outlier removal:
the second set of 10 bus voltage values read by the driver is:
382V,380V,381.8V,382.5V,378.8V,376V,377.1V,379V,386V,384.2V
the mean value of the set of data is:
the standard deviation is: s (V) = 2.975V
Determining the detection level alpha=0.05, n=10, and finding the corresponding critical value G of n, alpha in the "Grubbs test critical value table 1-α (n) = 2.176, and G n max = 1.7681, then G n max <G 1-α (n), the set of data is outlier free.
ThenThe mean of the first group should be further compared to the mean of the second group by approximately 5 times.
The mean values of the first group of nearly 5 times are known to be:
394.01V,386.05V,387.17V,389.12V,388.16V,
wherein the maximum value is 394.01V, the minimum value is 386.05V, and the difference between the two values is |394.01-386.05 |=796 < 10V, so that the requirements are met.
The mean values of the second group of nearly 5 times are known to be:
382.01V,381.05V,380.74V,379.21V,380.74V,
wherein the maximum value is 382.01V, the minimum value is 379.21V, and the difference between the two values is |382.01-379.21 |=2.8 < 10V, so that the requirement is met.
Although both groups meet the requirements, the difference of the average values of the two groups is more than 10V, and the machine should be stopped in an alarm mode.
Claims (2)
1. An intelligent voltage following brake device, characterized by comprising:
the isolation filtering module is used for filtering interference in the power supply system and reducing the influence of strong interference conducted by the power supply on the device;
the bus voltage sampling module is used for monitoring bus voltage change in real time and providing basis for determining a discharge voltage threshold value;
the bus current sampling module is used for detecting the direction of bus current, determining whether the motor dragging system is in an electric state or a power generation state currently, providing a criterion for determining the current value of bus voltage, indicating that the system is in the electric state when the current positively flows, indicating that the collected bus voltage can be used as the current value of the bus voltage, and indicating that the system is in the power generation state when the current negatively flows, wherein the voltage value cannot be used as the current value of the bus voltage;
the temperature sampling module is used for monitoring whether the brake main loop module is overheated or not in real time;
the signal acquisition conditioning module is used for converting and conditioning acquired signals and improving the acquisition precision;
the overvoltage protection module is used for executing a protection function when the system is in an overvoltage state;
the overcurrent protection module is used for executing a protection function when an overcurrent state occurs in the system;
the over-temperature protection module is used for executing a protection function when the system is in an over-temperature state;
the communication module is used for communicating with other modules of the system to read bus voltage and provide current state information of the device for the system;
the driving module is used for driving the braking main loop module;
the watchdog module is used for preventing the program from running off;
the central processing unit module is used for taking charge of the function realization of the whole system, including sampling, communication and fault logic judgment;
the braking main loop module is used for realizing the consumption of redundant electric energy in the braking process through the energy consumption resistor; the control method of the intelligent voltage following braking device comprises the following steps:
step 1: after the system is powered on, the watchdog module stops working and initializes the system;
step 2: after the necessary system configuration is completed, the watchdog is opened, communication with the driver is started, required information is read, and current, voltage and temperature physical quantity are collected;
step 3: judging whether the system has faults or not, and juxtaposing relevant flag bits;
step 4: judging whether the collected bus voltage is effective, determining the current value of the bus voltage under the condition of effectiveness, and calculating a discharge voltage threshold according to the current value of the bus voltage, so that the real-time control of the bus voltage is realized, and the bus overvoltage is prevented; the step 3 specifically comprises the following steps:
step 31: firstly judging whether the system has an overcurrent phenomenon, and if the system has the overcurrent phenomenon, carrying out overcurrent fault treatment; if the system does not have the overcurrent phenomenon, turning to the next step;
step 32: secondly, judging whether the system has overheat, and if so, performing overheat fault treatment; if the system does not have overheat, turning to the next step;
step 33: finally judging whether the system has overvoltage or undervoltage phenomenon, if the system has overvoltage or undervoltage phenomenon, carrying out overvoltage or undervoltage fault treatment; if the system does not have overvoltage or undervoltage, turning to step 4; the specific steps for acquiring the bus voltage in the steps are as follows:
step 41: the flow direction of the bus current determines whether a bus voltage sampling value is effective, when the current is positive, the motor state is indicated, the sampling value is effective, and when the current is negative, the generator state is indicated, and the sampling value is ineffective; if the current cannot be judged positive or negative, the busbar voltage sampling value is completely invalid;
step 42: under the condition that the current sampling value is positive, continuously collecting n busbar voltage values, andarranged from small to large as V 1 ,V 2 ,V 3 ,…,V n The sample mean and standard deviation of the bus voltage are respectively:
the method for detecting and rejecting outliers of the collected busbar voltage samples by utilizing Grubbs criteria comprises the following steps:
step 421; calculating statistics:
step 422; determining the detection level alpha, and finding the corresponding critical value G of n and alpha in a Grubbs test critical value table 1-α (n);
Step 423; determining whether or not there is an outlier, when G n >G′ n And G is n >G 1-α (n) determination of V n Is an outlier; when G' n >G n And G' n >G 1-α (n), then determine V 1 Is an outlier; otherwise, judging that the outlier is not present;
step 424; after outliers are removed, the average value of the bus voltage is recalculated according to the residual bus voltage sampling values and is used as the current value of the bus voltage
Step 43: by means of communicationThe bus voltage value detected by the read driver is detected and rejected by adopting the mode to obtain the current value of the bus voltage
Step 44: if it isAnd->Is similar in value, indicating that the system is normal, +.>And->Taking the average after the addition of the values of (2) as the current bus voltage value +.>;
Step 45: if it isAnd->The value difference of the voltage value is larger, which indicates that the system has failed, and the current bus voltage value should be given at the moment, so that the lower false alarm rate is ensured; if->The values of 5 times before and after are larger, which indicates +.>Problems may occur if +.>The values of the last 5 times differ little, in which case +.>The average value of the last few values is taken as the current bus voltage; if it isThe values of 5 times before and after are larger, which indicates +.>Problems may occur if +.>The values of the last 5 times are not very different, and +.>The average of the values of the last few times is taken as the current bus voltage;
step 46: if it isAnd->The values of (2) differ greatly and +.>The difference between the values of the two is larger before and after the system, which indicates that the system has serious faults; or->And->Is of a value of (a)Larger, although->The difference between the front value and the rear value of 5 times is not large, which also indicates that the system has serious faults, and at the moment, alarm signals are sent out and the system is stopped.
2. A control method of an intelligent voltage-following brake device according to claim 1, characterized by passing through the aboveThe value of (2) determines the voltage value of the current bus bar +.>The discharge voltage threshold is calculated as:
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Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1490294A (en) * | 1974-09-11 | 1977-10-26 | Bendix Corp | Adaptive braking system of a vehicle |
CN1667424A (en) * | 2005-02-26 | 2005-09-14 | 重庆大学 | Earth fault line-selecting method for arc suppression coil earthing system |
CN102521652A (en) * | 2012-01-10 | 2012-06-27 | 武汉大学 | Evaluation and decision method for operation efficiency of power grid |
CN103730905A (en) * | 2013-12-20 | 2014-04-16 | 杨仁刚 | Accumulator power supply simulation device and method |
CN106100461A (en) * | 2016-07-03 | 2016-11-09 | 国家电网公司 | A kind of flywheel turbine storage brake method |
CN106655436A (en) * | 2016-12-21 | 2017-05-10 | 苏州格远电气有限公司 | Charging apparatus and charging control method for backup power supply of wind power variable pitch system |
-
2017
- 2017-05-12 CN CN201710336215.4A patent/CN107134951B/en active Active
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1490294A (en) * | 1974-09-11 | 1977-10-26 | Bendix Corp | Adaptive braking system of a vehicle |
CN1667424A (en) * | 2005-02-26 | 2005-09-14 | 重庆大学 | Earth fault line-selecting method for arc suppression coil earthing system |
CN102521652A (en) * | 2012-01-10 | 2012-06-27 | 武汉大学 | Evaluation and decision method for operation efficiency of power grid |
CN103730905A (en) * | 2013-12-20 | 2014-04-16 | 杨仁刚 | Accumulator power supply simulation device and method |
CN106100461A (en) * | 2016-07-03 | 2016-11-09 | 国家电网公司 | A kind of flywheel turbine storage brake method |
CN106655436A (en) * | 2016-12-21 | 2017-05-10 | 苏州格远电气有限公司 | Charging apparatus and charging control method for backup power supply of wind power variable pitch system |
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