Bus current estimation method and device based on GTM module
By using GTM module in the motor controller for bus current estimation, the problems of high hardware cost, large workload and poor calculation accuracy in the prior art are solved, and a more efficient and simpler bus current calculation method is realized.
Patent Information
- Application Number
- CN202411661830.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-20
- Publication Date
- 2025-03-07
AI Technical Summary
The existing bus current calculation methods have problems such as high hardware cost, large workload, few acquisition cycles and poor calculation accuracy.
The bus current estimation method based on the GTM module is adopted, and the three-phase current value of the motor is collected through the periodic current sampling trigger signal sent by the GTM module, combined with the IGBT switch state of the upper bridge arm of the three-phase inverter, and the average filtering is performed to obtain the bus current value.
It reduces hardware costs, reduces the workload of trench calibration, improves the accuracy of bus current calculation and the simplicity of algorithms, and avoids the CPU resources of the main chip alone.
Smart Images
Figure CN119582691A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of bus current estimation, and in particular to a bus current estimation method and device based on a GTM module. Background Art
[0002] Motor controllers in new energy vehicles are widely used in electric vehicles and other fields. Motor controllers are mainly used for torque execution, but new energy vehicles require motor controllers to provide bus current as a reference to achieve energy management of the entire vehicle. In order to meet the capacity management requirements of the entire vehicle, it is necessary to provide the bus current of the motor controller.
[0003] The current methods for motor controllers to calculate bus current are: 1. Measure through bus current sensor and directly output bus current.
[0004] 2. Through bench calibration, record the bus current values under different speeds, different voltages, and different torques, and the software can achieve this through table lookup.
[0005] 3. The three-phase current is collected once every PWM cycle through the ADC, and then the bus current value is calculated through the software algorithm based on the PWM duty cycle of the IGBT drive output by the motor control algorithm and the compensation coefficient calibrated by the bench.
[0006] Solution 1: Increase hardware cost. Solution 2: The workload of bench calibration is large and not universal. Solution 3: Since the three-phase current sampling cycle is the same as the IGBT controller cycle, it can only be collected once per cycle, and it needs to be combined with the motor control algorithm, resulting in poor calculation accuracy and complex algorithm, which needs to be corrected on the bench. Summary of the invention
[0007] The present invention mainly solves the problems of high hardware cost, heavy workload, few acquisition cycles, poor calculation accuracy and complex algorithm in the existing bus current calculation, and provides a bus current estimation method and device based on the GTM module.
[0008] The above technical problem of the present invention is mainly solved by the following technical solution: A bus current estimation method based on a GTM module comprises the following steps: According to the periodic current sampling trigger signal sent by the GTM module, the three-phase current sampling values of the motor are collected and obtained; Obtain the IGBT switch status signal of the upper bridge arm of the three-phase inverter; According to the IGBT switch state of each upper bridge arm of the three-phase inverter, the three-phase current sampling value is selected to set the three-phase current value; The candidate bus current value is obtained by summing the three-phase current values, and the candidate bus current values of all samples within the filtering period are obtained, and the bus current value is obtained by performing mean filtering.
[0009] The present invention calculates the real-time three-phase current through the GTM module, reduces bench calibration and cancels the bus current sensor, obtains the three-phase current value and calculates the bus current value according to the IGBT switch state of each upper bridge arm of the three-phase inverter and the current sampling value, and has a simple algorithm, and can run logical operations in the GTM programmable module without using the CPU resources of the main chip alone.
[0010] As a preferred solution, the current sampling trigger signal period is smaller than the motor control switch period / 10.
[0011] In this solution, the cycle time t of the current sampling trigger signal sent by the GTM module is set to be less than the motor control switch cycle / 10. This setting is used to avoid the problem of bus current calculation distortion.
[0012] As a preferred solution, the upper bridge arm IGBT switch signal connected to the U phase is obtained. When the switch is in the on state, the U-phase current value is the U-phase current sampling value. When the switch is in the off state, the U phase current value is 0.
[0013] When the upper bridge arm IGBT is turned on, the current flowing through the upper bridge arm is the current value sampled by the three phases. For the upper bridge arm IGBT switch connected to the U phase, the upper bridge arm IGBT switch state SUh is detected. When SUh=1, the U phase current value iuh=U phase sampling current value iu; when SUh=0, the U phase current value iuh=0.
[0014] As a preferred solution, the upper bridge arm IGBT switch signal connected to the V phase is obtained. When the switch is in the on state, the V phase current value is the V phase current sampling value, When the switch is in the off state, the V phase current value is 0.
[0015] When the upper bridge arm IGBT is turned on, the current flowing through the upper bridge arm is the three-phase sampled current value. For the upper bridge arm IGBT switch connected to the V phase, the upper bridge arm IGBT switch state SVh is detected. When SVh=1, the V phase current value ivh=V phase sampled current value iv; when SVh=0, the V phase current value ivh=0.
[0016] As a preferred solution, the upper bridge arm IGBT switch signal connected to the W phase is obtained. When the switch is in the on state, the W phase current value is the W phase current sampling value, When the switch is in the off state, the W phase current value is 0.
[0017] When the upper arm IGBT is turned on, the current flowing through the upper arm is the three-phase sampled current value. For the upper arm IGBT switch connected to the W phase, the upper arm IGBT switch state SWh is detected. When SWh=1, the W phase current value iwh=W phase sampled current value iw; when SWh=0, the W phase current value iwh=0.
[0018] As a preferred solution, the three-phase current values are obtained according to the IGBT switch states of the three-phase upper bridge arms and the three-phase current sampling values, and the candidate bus current values are calculated. The candidate bus current value is the sum of the three-phase current values.
[0019] The three-phase current value is determined according to the IGBT switch state of the three-phase upper bridge arm, and according to Kirchhoff's law, the candidate bus current value ibus is calculated as U-phase current value iuh + V-phase current value ivh + W-phase current value iwh.
[0020] As a preferred solution, a filtering period is set, all sampled candidate bus current values are obtained within the filtering period, and the obtained candidate bus current values are averaged to obtain the bus current value within the current filtering period.
[0021] The candidate bus current values of all samples in the filtering period are obtained, and the candidate bus current values are averaged. The final calculated value is used as the bus current value of the current filtering period. The average calculation is performed to obtain a more accurate bus current value.
[0022] As a preferred solution, the filtering cycle time should be greater than the motor control switching cycle*10.
[0023] A bus current estimation device based on a GTM module, comprising: Three-phase current sensor, detecting the current of the three-phase circuit of the motor; The sampling module obtains the three-phase current value of the motor detected by the three-phase current sensor; IO module, obtains the three-phase upper bridge arm IGBT switch status signal; The GTM module and the timing period phase sampling module send a current sampling trigger signal to obtain the three-phase current value of the motor and the three-phase upper bridge arm IGBT switch status signal, and calculate the bus current value.
[0024] The three-phase current sensors in the device of the present invention are respectively installed on the three-phase circuits of the motor to detect the current of the three-phase circuits of the motor. The three-phase current sensor is connected to the sampling module through an operational amplifier module. The sampling module adopts a DSADC sampling module or a VADC sampling module, and the module is connected to the GTM module. The sampling module receives the periodic current sampling trigger signal sent by the GTM module, collects the signal detected by the three-phase current sensor according to the current sampling trigger signal, obtains the three-phase current sampling value and sends it to the GTM module. The IO module collects the three-phase upper bridge arm IGBT switch state information and sends it to the GTM module. The GTM module obtains the three-phase current value according to the three-phase upper bridge arm IGBT switch state and the three-phase current sampling value, and obtains the bus current value by summing up after determining the three-phase current value. Set the filtering period, obtain all sampled candidate bus current values within the filtering period, and average the obtained candidate bus current values to obtain the bus current value within the current filtering period.
[0025] As a preferred solution, the GTM module includes an ARU module, an MCS module and a storage module. The ARU module is interconnected with the GTM module, the MCS module is interconnected with the storage module, the storage module is connected to the motor controller, and the IO module and the sampling module are respectively connected to the ARU module.
[0026] The GTM module includes the ARU module and the MCS module, where ARU stands for Advanced Routing Unit and MSC stands for Multi Channel Sequencer. The MSC module can program simple logic operations and is independent of the CPU. The MSC module receives the IO state, i.e. the switch state of the upper bridge arm IGBT, calculates the output bus current value, stores it in the storage module, and then obtains it from the storage module when the CPU uses the bus current value.
[0027] Therefore, the advantages of the present invention are: the three-phase current value is obtained and the bus current value is calculated according to the IGBT switch state of each upper bridge arm of the three-phase inverter and the current sampling value, and the algorithm is simple. The real-time three-phase current is calculated by running the GTM module, the bench calibration and the bus current sensor are eliminated, and the hardware cost is reduced. The logical operation can be run in the GTM programmable module without using the CPU resources of the main chip alone. The three-phase current sampling is performed according to the GTM module trigger signal, and multiple samplings are controlled within the switch cycle, which improves the accuracy of the bus current value calculation. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] Figure 1 It is a schematic diagram of a process of the present invention.
[0029] Figure 2 It is a structural block diagram of the present invention.
[0030] Figure 3 It is a structural block diagram of the GTM module in the present invention.
[0031] 1- three-phase current sensor 2- operational amplifier module 3- sampling module 4- IO module 5- GTM module 51- ARU module 52- MCS module 53- storage module. DETAILED DESCRIPTION
[0032] The technical solution of the present invention is further specifically described below through embodiments and in conjunction with the accompanying drawings.
[0033] Embodiment 1: This embodiment provides a bus current estimation method based on a GTM module, such as Figure 1 As shown, the following process is included: According to the periodic current sampling trigger signal sent by the GTM module, the three-phase current sampling values of the motor are collected and obtained.
[0034] As a preferred solution of this embodiment, the cycle time t for sending the current sampling trigger signal is set in the GTM module, and the current trigger sampling signal cycle time t is required to be less than one tenth of the motor control switch cycle T, that is, t<T / 10. The cycle time setting of the current trigger sampling signal is used to avoid the problem of bus current calculation distortion.
[0035] The GTM module sends a periodic current sampling trigger signal to the sampling module, triggering the sampling module to sample the three-phase current. Specifically, the three-phase current is detected in real time by a three-phase current sensor set on the three-phase circuit of the motor. The detected information is sent to the sampling module through the operational amplifier module, and the sampling module obtains the three-phase current sampling value according to the detected information.
[0036] Obtain the IGBT switch status signal of the upper bridge arm of the three-phase inverter; After the current sampling is completed, the GTM module obtains the switch state information of the IGBT of each upper bridge arm of the three-phase inverter. Specifically, the IO module obtains the switch state information of the IGBT of each upper bridge arm of the three-phase inverter and transmits the information to the GTM module.
[0037] According to the IGBT switch state of each upper bridge arm of the three-phase inverter, the three-phase current sampling value is selected to set the three-phase current value.
[0038] As a preferred solution of this embodiment, the three-phase current value is determined according to the IGBT switch signal of each upper bridge arm of the three-phase inverter and the three-phase current sampling value. When the upper bridge arm IGBT is turned on, the current flowing through the upper bridge arm is the three-phase sampled current value.
[0039] Determination of U-phase current value Get the upper bridge arm IGBT switch signal connected to the U phase, When the switch is in the on state, the U-phase current value is the U-phase current sampling value. When the switch is in the off state, the U phase current value is 0.
[0040] Determination of V-phase current value Get the upper bridge arm IGBT switch signal connected to the V phase, When the switch is in the on state, the V phase current value is the V phase current sampling value, When the switch is in the off state, the V phase current value is 0.
[0041] Determination of W-phase current value Get the upper bridge arm IGBT switch signal connected to phase W, When the switch is in the on state, the W phase current value is the W phase current sampling value, When the switch is in the off state, the W phase current value is 0.
[0042] The candidate bus current value is obtained by summing the three-phase current values, and the candidate bus current values of all samples within the filtering period are obtained, and the bus current value is obtained by performing mean filtering.
[0043] As a preferred scheme of this embodiment, after obtaining the three-phase current value according to the IGBT switch state of the three-phase upper bridge arm and the three-phase current sampling value, the candidate bus current value is calculated. According to Kirchhoff's law, the candidate bus current value is the sum of the three-phase current values, that is, the candidate bus current value = U-phase current value + V-phase current value + W-phase current value.
[0044] The filter period Tf is preset, and the filter period Tf time must be greater than 10 times the motor control switch period T, that is, Tf>T*10.
[0045] All sampled candidate bus current values are obtained within the filtering period Tf, and the obtained candidate bus current values are averaged to obtain the bus current value within the current filtering period.
[0046] Specifically, all sampled candidate bus current values within the filtering period Tf are obtained, and the candidate bus current values are averaged, and the final calculated value is used as the bus current value of the current filtering period. This solution obtains a more accurate bus current value by averaging.
[0047] This embodiment also provides a bus current estimation device based on a GTM module, which is used to implement the above bus current estimation method. Figure 2As shown, the specific structure includes a three-phase current sensor 1, an operational amplifier module 2, a sampling module 3, an IO module 4, and a GTM module 5. The three-phase current sensor 1 is connected to the operational amplifier module 2, and then connected to the sampling module 3 through the operational amplifier module. The sampling module 3 is connected to the GTM module 5, the IO module 4 is connected to the GTM module 5, and the control signal end of the GTM module 5 is connected to the sampling module 3.
[0048] The three-phase current sensor 1 is installed on the three-phase circuit of the motor respectively, and is used to detect the current of the three-phase circuit of the motor. The three-phase current sensor is connected to the sampling module through the operational amplifier module 2. The three-phase current sensor detects the current value of the three-phase circuit in real time. After the sampling module receives the periodic current sampling trigger signal, the detected three-phase current value is sent to the acquisition module through the operational amplifier module 2 to obtain the three-phase current sampling value.
[0049] The sampling module 2 adopts a DSADC sampling module or a VADC sampling module, and the module is connected to the GTM module 5. The sampling module receives the periodic current sampling trigger signal sent by the GTM module, collects the signal detected by the three-phase current sensor according to the current sampling trigger signal, obtains the three-phase current sampling value and sends it to the GTM module.
[0050] IO module 4 collects the three-phase upper bridge arm IGBT switch status information and sends the three-phase upper bridge arm IGBT switch status information to the GTM module.
[0051] GTM module 5 sets the current sampling trigger signal cycle, periodically sends the current sampling trigger model to the sampling module, receives the three-phase current sampling values sent by the sampling module and the three-phase upper bridge arm IGBT switch status information sent by the IO module, determines the three-phase current value according to the three-phase upper bridge arm IGBT switch status and the three-phase current sampling value, and obtains the bus current value by summing up after determining the three-phase current value. Set the filtering cycle, obtain all sampled candidate bus current values within the filtering cycle, and average the obtained candidate bus current values to obtain the bus current value within the current filtering cycle.
[0052] like Figure 3 As shown, the GTM module includes an ARU module 51, an MCS module 52 and a storage module 53. The ARU module 51 is interconnected with the GTM module 52, the MCS module 52 is interconnected with the storage module 53, the storage module 53 is connected to the motor controller, and the IO module 4 and the sampling module 5 are respectively connected to the ARU module 51.
[0053] ARU stands for Advanced Routing Unit, and MSC stands for Multi Channel Sequencer. The MSC module can program simple logic operations and is independent of the CPU. The MSC module receives the IO state, i.e. the switch state of the upper bridge arm IGBT, calculates the output bus current value, stores it in the storage module, and then obtains it from the storage module when the motor controller CPU uses the bus current value.
[0054] Embodiment 2: This embodiment provides another implementation of a bus current estimation method based on a GTM module, which specifically includes the following process: S1. According to the periodic current sampling trigger signal sent by the GTM module, the three-phase current sampling values of the motor are collected and obtained.
[0055] As a preferred solution of this embodiment, the cycle time t for sending the current sampling trigger signal is set in the GTM module, and the current trigger sampling signal cycle time t is required to be less than one tenth of the motor control switch cycle T, that is, t<T / 10. The cycle time setting of the current trigger sampling signal is used to avoid the problem of bus current calculation distortion.
[0056] The GTM module sends a periodic current sampling trigger signal to the sampling module, triggering the sampling module to sample the three-phase current. Specifically, the three-phase current is detected in real time by a three-phase current sensor set on the three-phase circuit of the motor, and the detected information is sent to the sampling module through the operational amplifier module. The sampling module obtains the three-phase current sampling values iu, iv, and iw according to the detected information.
[0057] S2. Obtain the IGBT switch status signal of the upper bridge arm of the three-phase inverter; After the current sampling is completed, the GTM module obtains the switch state information SUh, SVh, and SWh of the upper bridge arm IGBTs of the three-phase inverter. Specifically, the IO module obtains the switch state information of the upper bridge arm IGBTs of the three-phase inverter and transmits the information to the GTM module.
[0058] S3. According to the IGBT switch state of each upper bridge arm of the three-phase inverter, select the three-phase current sampling value to set the three-phase current value.
[0059] As a preferred solution of this embodiment, the three-phase current value is determined according to the IGBT switch signal of each upper bridge arm of the three-phase inverter and the three-phase current sampling value. When the upper bridge arm IGBT is turned on, the current flowing through the upper bridge arm is the three-phase sampled current value.
[0060] Determination of U-phase current value For the upper bridge arm IGBT switch connected to the U phase, the upper bridge arm IGBT switch state SUh is detected. When SUh=1, the U-phase current value iuh=U-phase sampling current value iu; When SUh=0, the U-phase current value iuh=0.
[0061] Determination of V-phase current value For the upper bridge arm IGBT switch connected to the V phase, the upper bridge arm IGBT switch state SVh is detected. When SVh=1, V phase current value ivh=V phase sampling current value iv; When SVh=0, the V-phase current value ivh=0.
[0062] Determination of W-phase current value For the upper bridge arm IGBT switch connected to the W phase, the upper bridge arm IGBT switch state SWh is detected. When SWh=1, the W-phase current value iwh=the W-phase sampling current value iw; When SWh=0, the W-phase current value iwh=0.
[0063] S4. Obtain the candidate bus current value based on the sum of the three-phase current values, obtain all sampled candidate bus current values within the filtering period, and perform mean filtering to obtain the bus current value.
[0064] As a preferred solution of this embodiment, after obtaining the three-phase current value according to the IGBT switch state of the three-phase upper bridge arm and the three-phase current sampling value, the candidate bus current value ibus is calculated. According to Kirchhoff's law, the candidate bus current value is the sum of the three-phase current values, that is, ibus=iuh+ivh+iwh The filter period Tf is preset, and the filter period Tf time must be greater than 10 times the motor control switch period T, that is, Tf>T*10.
[0065] All sampled candidate bus current values are obtained within the filtering period Tf, and the obtained candidate bus current values are averaged to obtain the bus current value within the current filtering period.
[0066] Specifically, all sampled candidate bus current values within the filtering period Tf are obtained, and the candidate bus current values are averaged, and the final calculated value is used as the bus current value of the current filtering period. This solution obtains a more accurate bus current value by averaging.
[0067] This embodiment also includes a bus current estimation device based on a GTM module, which is used to implement the above bus current estimation method, such as Figure 2As shown, the specific structure includes a three-phase current sensor 1, an operational amplifier module 2, a sampling module 3, an IO module 4, and a GTM module 5. The three-phase current sensor 1 is connected to the operational amplifier module 2, and then connected to the sampling module 3 through the operational amplifier module. The sampling module 3 is connected to the GTM module 5, the IO module 4 is connected to the GTM module 5, and the control signal end of the GTM module 5 is connected to the sampling module 3.
[0068] The three-phase current sensor 1 is installed on the three-phase circuit of the motor respectively, and is used to detect the current of the three-phase circuit of the motor. The three-phase current sensor is connected to the sampling module through the operational amplifier module 2. The three-phase current sensor detects the current value of the three-phase circuit in real time. After the sampling module receives the periodic current sampling trigger signal, the detected three-phase current value is sent to the acquisition module through the operational amplifier module 2 to obtain the three-phase current sampling value.
[0069] The sampling module 2 adopts a DSADC sampling module or a VADC sampling module, and the module is connected to the GTM module 5. The sampling module receives the periodic current sampling trigger signal sent by the GTM module, collects the signal detected by the three-phase current sensor according to the current sampling trigger signal, obtains the three-phase current sampling value and sends it to the GTM module.
[0070] IO module 4 collects the three-phase upper bridge arm IGBT switch status information and sends the three-phase upper bridge arm IGBT switch status information to the GTM module.
[0071] GTM module 5 sets the current sampling trigger signal cycle, periodically sends the current sampling trigger model to the sampling module, receives the three-phase current sampling values sent by the sampling module and the three-phase upper bridge arm IGBT switch status information sent by the IO module, determines the three-phase current value according to the three-phase upper bridge arm IGBT switch status and the three-phase current sampling value, and obtains the bus current value by summing up after determining the three-phase current value. Set the filtering cycle, obtain all sampled candidate bus current values within the filtering cycle, and average the obtained candidate bus current values to obtain the bus current value within the current filtering cycle.
[0072] like Figure 3 As shown, the GTM module includes an ARU module 51, an MCS module 52 and a storage module 53. The ARU module 51 is interconnected with the GTM module 52, the MCS module 52 is interconnected with the storage module 53, the storage module 53 is connected to the motor controller, and the IO module 4 and the sampling module 5 are respectively connected to the ARU module 51.
[0073] ARU stands for Advanced Routing Unit, and MSC stands for Multi Channel Sequencer. The MSC module can program simple logic operations and is independent of the CPU. The MSC module receives the IO state, i.e. the switch state of the upper bridge arm IGBT, calculates the output bus current value, stores it in the storage module, and then obtains it from the storage module when the motor controller CPU uses the bus current value.
[0074] Embodiment 3: This embodiment provides a third implementation of a bus current estimation method based on a GTM module, which specifically includes the following steps: S1. According to the periodic current sampling trigger signal sent by the GTM module, the three-phase current sampling values of the motor are collected and obtained.
[0075] As a preferred solution of this embodiment, the cycle time t of sending the current sampling trigger signal is set in the GTM module.
[0076] The GTM module sends a periodic current sampling trigger signal to the sampling module, triggering the sampling module to sample the three-phase current. Specifically, the three-phase current is detected in real time by a three-phase current sensor set on the three-phase circuit of the motor. The detected information is sent to the sampling module through the operational amplifier module, and the sampling module obtains the three-phase current sampling value according to the detected information.
[0077] S2. Obtaining the on / off signal of the IGBT switch of the upper bridge arm of the three-phase inverter; The GTM module obtains the on-off signals of the IGBT switches of each upper bridge arm of the three-phase inverter, including the switch states SUh, SVh, SWh of each upper bridge arm IGBT, the on-time SUTo, SVTo, SWTo of each upper bridge arm IGBT switch, and the off-time SUTc, SVTc, SWTc of each upper bridge arm IGBT switch, and transmits the above information to the GTM module.
[0078] S3. According to the IGBT switch state of each upper bridge arm of the three-phase inverter, select the three-phase current sampling value to determine the three-phase current value, and select the three-phase current value when the IGBT switch of each upper bridge arm is in the on state as the final three-phase current value.
[0079] As a preferred solution of this embodiment, the three-phase current value is determined according to the IGBT switch signal of each upper bridge arm of the three-phase inverter and the three-phase current sampling value. When the upper bridge arm IGBT is turned on, the current flowing through the upper bridge arm is the three-phase sampled current value.
[0080] Determination of U-phase current value For the upper bridge arm IGBT switch connected to the U phase, the upper bridge arm IGBT switch state SUh is detected. When SUh=1, the U-phase current value iuh=U-phase sampling current value iu; When SUh=0, the U-phase current value iuh=0.
[0081] Determination of V-phase current value For the upper bridge arm IGBT switch connected to the V phase, the upper bridge arm IGBT switch state SVh is detected. When SVh=1, V phase current value ivh=V phase sampling current value iv; When SVh=0, the V-phase current value ivh=0.
[0082] Determination of W phase current value For the upper bridge arm IGBT switch connected to the W phase, the upper bridge arm IGBT switch state SWh is detected. When SWh=1, the W-phase current value iwh=the W-phase sampling current value iw; When SWh=0, the W-phase current value iwh=0.
[0083] The GTM module selects the conduction state of each upper bridge arm IGBT switch from the three-phase current sampling values, that is, the three-phase current sampling values when SUh, SVh, and SWh are equal to 1, and averages the multiple current sampling values to obtain the final three-phase current sampling values iu, iv, and iw.
[0084] S4. Calculate the candidate bus current value according to the on-off time of each upper bridge arm IGBT switch and the three-phase current value.
[0085] The on-time of each upper arm IGBT switch is calculated based on the difference between the on-time and off-time of each upper arm IGBT switch. The candidate bus current value is calculated by combining the three-phase current sampling values iu, iv, iw in the on state and the motor control cycle t. The specific calculation is: ibus=[iu(SUTc- SUTo)+iv(SVTc- SVTo)+iw(SWTc- SWTo)] / t S5. Obtain candidate bus current values of multiple periods t, and perform mean filtering to obtain bus current values.
[0086] Specifically, all sampled candidate bus current values within multiple motor control cycles t are obtained, and these candidate bus current values are averaged, and the final calculated value is used as the bus current value. This solution obtains a more accurate bus current value by averaging.
[0087] This embodiment also includes a bus current estimation device based on the GTM module, which is used to implement the method in Example 3. The device includes: a three-phase current sensor 1, an operational amplifier module 2, a sampling module 3, an IO module 4, and a GTM module 5. The three-phase current sensor 1 is connected to the operational amplifier module 2, and then connected to the sampling module 3 through the operational amplifier module. The sampling module 3 is connected to the GTM module 5, the IO module 4 is connected to the GTM module 5, and the control signal end of the GTM module 5 is connected to the sampling module 3.
[0088] The GTM module includes an ARU module 51, an MCS module 52 and a storage module 53. The ARU module 51 is interconnected with the GTM module 52, the MCS module 52 is interconnected with the storage module 53, the storage module 53 is connected to the motor controller, and the IO module 4 and the sampling module 5 are respectively connected to the ARU module 51.
[0089] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.
[0090] Although this article uses more terms such as three-phase current sensor, operational amplifier module, sampling module, IO module, GTM module, etc., it does not exclude the possibility of using other terms. These terms are used only to more conveniently describe and explain the essence of the present invention; interpreting them as any additional restrictions is contrary to the spirit of the present invention.
Claims
1. A bus current estimation method based on a GTM module, characterized in that: The following steps are involved: According to the periodic current sampling trigger signal sent by the GTM module, the three-phase current sampling values of the motor are collected and obtained; Obtain the IGBT switch status signal of the upper bridge arm of the three-phase inverter; According to the IGBT switch state of each upper bridge arm of the three-phase inverter, the three-phase current sampling value is selected to set the three-phase current value; The candidate bus current value is obtained by summing the three-phase current values, and the candidate bus current values of all samples within the filtering period are obtained, and the bus current value is obtained by performing mean filtering.
2. The bus current estimation method based on the GTM module according to claim 1 is characterized in that: The current sampling trigger signal period must be less than the motor control switch period / 10.
3. The bus current estimation method based on the GTM module according to claim 1 is characterized in that: Get the upper bridge arm IGBT switch signal connected to the U phase, When the switch is in the on state, the U-phase current value is the U-phase current sampling value. When the switch is in the off state, the U phase current value is 0.
4. The bus current estimation method based on the GTM module according to claim 3 is characterized in that: Get the upper bridge arm IGBT switch signal connected to the V phase, When the switch is in the on state, the V phase current value is the V phase current sampling value, When the switch is in the off state, the V phase current value is 0.
5. The bus current estimation method based on the GTM module according to claim 4 is characterized in that: Get the upper bridge arm IGBT switch signal connected to phase W, When the switch is in the on state, the W phase current value is the W phase current sampling value, When the switch is in the off state, the W phase current value is 0.
6. A bus current estimation method based on a GTM module according to claim 3, 4 or 5, characterized in that: The three-phase current values are obtained according to the IGBT switch states of the three-phase upper bridge arms and the three-phase current sampling values, and the candidate bus current values are calculated. The candidate bus current value is the sum of the three-phase current values.
7. The bus current estimation method based on the GTM module according to claim 1 is characterized in that: A filtering period is set, and all sampled candidate bus current values are obtained within the filtering period. The obtained candidate bus current values are averaged to obtain the bus current value within the current filtering period.
8. A bus current estimation method based on a GTM module according to claim 1 or 7, characterized in that: The filter cycle time must be greater than the motor control switching cycle*10.
9. A bus current estimation device based on a GTM module, implementing the method described in any one of claims 1 to 8, characterized in that: include Three-phase current sensor, detecting the current of the three-phase circuit of the motor; The sampling module obtains the three-phase current value of the motor detected by the three-phase current sensor; IO module, obtains the three-phase upper bridge arm IGBT switch status signal; The GTM module and the timing period phase sampling module send a current sampling trigger signal to obtain the three-phase current value of the motor and the three-phase upper bridge arm IGBT switch status signal, and calculate the bus current value.
10. A bus current estimation device based on a GTM module according to claim 9, characterized in that The GTM module includes an ARU module, an MCS module and a storage module. The ARU module is interconnected with the GTM module, the MCS module is interconnected with the storage module, the storage module is connected with the motor controller, and the IO module and the sampling module are respectively connected with the ARU module.