A control method and control device of a motor controller

Abstract

The present invention discloses a control method for a motor controller, comprising: cutting the full speed range of the motor controller into several speed intervals, and cutting each speed interval into several random speed intervals; obtaining the current speed of the motor controller, and determining which random speed interval the current speed falls into; performing random number calculation processing on the random speed interval in which the current speed falls, and generating a random switching frequency for the switch control of the motor controller; obtaining the current current value and the current electrical angle value of the motor controller, and generating an SVPWM pulse control signal; limiting the safe dead time of the motor controller, and outputting the SVPWM pulse control signal according to the limiting processing result. A control device for realizing the control method of the motor controller is also disclosed. The present invention widens the frequency conversion range of the motor controller, improves the output efficiency, improves the vehicle endurance, and improves the NVH index.

Description

Technical Field

[0001] The present invention relates to the technical field of motor controllers, and in particular to a control method and a control device of a motor controller. Background Art

[0002] The current motor controllers are all based on SVPWM modulation technology with fixed switching frequency or stepless frequency conversion. The motor controller with fixed switching frequency control has large switching loss at low speed, and the carrier and its frequency multiples will bring high-frequency current harmonics. The current harmonic components will generate high-frequency harmonic magnetic fields, causing high-frequency vibrations, thereby causing high-frequency noise, which will bring an uncomfortable experience to electric vehicle users.

[0003] In addition, there are also stepless frequency conversion motor controllers on the market, but their current ripple is relatively large at low frequencies, and frequency conversion at high frequencies requires relatively high chip resources, and cannot achieve frequency conversion over a wider range.

[0004] Therefore, the applicant has found a solution to the above-mentioned problem through beneficial exploration and research, and the technical solution to be introduced below is produced in this context. Summary of the invention

[0005] One of the technical problems to be solved by the present invention is to provide a control method for a motor controller with a random frequency jittering function based on a fixed calculation cycle to improve the frequency conversion range and efficiency in view of the deficiencies in the prior art.

[0006] The second technical problem to be solved by the present invention is to provide a control device for implementing the control method of the motor controller.

[0007] As a first aspect of the present invention, a control method of a motor controller comprises the following steps:

[0008] Step S100, cutting the full speed range of the motor controller into a plurality of speed intervals, and cutting each speed interval into a plurality of random speed intervals;

[0009] Step S200, obtaining the current speed of the motor controller, and determining which random speed interval the current speed falls into;

[0010] Step S300, performing random number calculation processing on the random speed interval into which the current speed falls, and generating a random switching frequency for switching control of the motor controller;

[0011] Step S400, obtaining a current current value and a current electrical angle value of the motor controller, and generating an SVPWM pulse control signal according to the current current value, the current electrical angle value and the random switching frequency and in a fixed current loop period;

[0012] Step S500, limiting the safety dead time of the motor controller, and outputting the SVPWM pulse control signal according to the limiting processing result.

[0013] In a preferred embodiment of the present invention, in step S100, the full speed range of the motor controller is divided into 9 speed intervals, and each speed interval is divided into 3 random speed intervals.

[0014] In a preferred embodiment of the present invention, in step S300, a linear congruential method is used to perform random number calculation processing on the random speed interval into which the current speed falls, and the calculation formula is:

[0015] x n+1 =Mod(a*x n +c,m)

[0016] o=x n+1 / m

[0017] y=(o+0.5)*t s

[0018] Among them, a is the multiplier, c is the increment, m is the modulus, t s is the center point.

[0019] In a preferred embodiment of the present invention, in step S400, the obtaining of the current current value and the current electrical angle value of the motor controller, and the calculation and generation of an SVPWM pulse control signal according to the current current value, the current electrical angle value and the random switching frequency and in a fixed current loop period include the following steps:

[0020] Step S401, calculating a random SVPWM period according to a fixed current loop period;

[0021] Step S402, calculating the IGBT switching time of the random SVPWM cycle;

[0022] Step S403, the PWM module channels x+1 and x+2 of the TC275 chip of the motor controller are used as reference triggers to collect the current current value and the current electrical angle value;

[0023] Step S404, the PWM module channel x+3 of the TC275 chip of the motor controller is triggered to generate a random SVPWM switching cycle;

[0024] Step S405 , the complex PWM module channel random switching cycle is used as a base to generate an SVPWM pulse control signal to control the on and off of the driving IGBT.

[0025] In a preferred embodiment of the present invention, in step S500, the limiting process of the safety dead time of the motor controller and outputting the SVPWM pulse control signal according to the limiting process result include the following steps:

[0026] Step S501, obtaining a current task and receiving an IGBT switch signal;

[0027] Step S502, determining whether the IGBT switching time is greater than 0 μs and less than the time T that can vary with the frequency, if so, proceeding to step S503, otherwise proceeding to step S509;

[0028] Step S503, determine whether the closing time of the lower half bridge is greater than the opening time of the upper half bridge, whether the shut-down time of the upper half bridge is greater than the opening time of the lower half bridge, and whether the difference between the upper and lower half bridge times is less than the minimum protection time t1. If so, proceed to step S504;

[0029] Step S504, setting the lower half bridge shutdown time to the upper half bridge opening time minus the minimum protection time t1, and setting the lower half bridge opening time to the upper half bridge shutdown time plus the minimum protection time t1;

[0030] Step S505, determining whether the current duty cycle of the motor controller is less than the minimum allowable duty cycle, if so, proceeding to step S506, if not, proceeding to step S516;

[0031] Step S506, outputting the ASC mode;

[0032] Step S507, determining whether the current duty cycle of the motor controller is greater than the maximum allowable duty cycle, if so, proceeding to step S508, if not, proceeding to step S516;

[0033] Step S508, output the maximum allowable duty cycle, and proceed to step S516;

[0034] Step S509, determining whether the motor controller complies with the upper and lower ASC mode or the OC mode, if so, proceeding to step S510, if not, proceeding to step S516;

[0035] Step S510, determining whether the upper half bridge opening time is greater than the time T that can change with the frequency or whether the lower half bridge closing time is greater than the time T that can change with the frequency, if so, proceeding to step S511, if not, proceeding to step S513;

[0036] Step S511, determine whether the difference between the lower half bridge opening time and the upper half bridge closing time is less than the minimum protection time t1, if so, proceed to step S512, if not, proceed to step S516;

[0037] Step S512, set the lower half bridge opening time to the upper half bridge closing time plus the protection minimum time t1, and proceed to step S516;

[0038] Step S513, determining whether the upper half bridge shutdown time is greater than the time T that can change with the frequency or the lower half bridge opening time is greater than the time T that can change with the frequency, if so, proceeding to step S514, if not, proceeding to step S516;

[0039] Step S514, determine whether the difference between the upper half bridge opening time and the lower half bridge closing time is less than the minimum protection time t1, if so, proceed to step S515, if not, proceed to step S516;

[0040] Step S515, set the upper half bridge opening time to the lower half bridge closing time plus the protection minimum time t1, and proceed to step S516;

[0041] Step S516: output the SVPWM pulse control signal normally.

[0042] In a preferred embodiment of the present invention, the time T that can change with the frequency is 1 / F, and F is the current jitter frequency.

[0043] As a second aspect of the present invention, a control device for implementing the control method of the motor controller includes:

[0044] A speed cutting module, the speed cutting module is used to cut the full speed range of the motor controller into several speed intervals, and cut each speed interval into several random speed intervals;

[0045] A speed determination module, the speed determination module is used to obtain the current speed of the motor controller and determine which random speed interval the current speed falls into;

[0046] A random number calculation module, the random number calculation module is used to perform random number calculation processing on the random speed interval into which the current speed falls, and generate a random switching frequency for switch control of the motor controller;

[0047] A pulse control signal generating module, the pulse control signal generating module is used to obtain the current current value and the current electrical angle value of the motor controller, and calculate and generate an SVPWM pulse control signal according to the current current value, the current electrical angle value and the random switching frequency and in a fixed current loop period; and

[0048] A safety dead zone protection module is used to limit the safety dead zone time of the motor controller and output the SVPWM pulse control signal according to the limit processing result.

[0049] Due to the adoption of the above technical solution, the beneficial effect of the present invention is that the present invention adds random frequency jitter control on the basis of the traditional motor controller, so that the frequency conversion range of the motor controller is widened, the output efficiency is improved, and thus the vehicle endurance is improved, while the harmonic component of the power system circuit is reduced, thereby improving the NVH index and improving the vehicle use experience. In addition, the dead zone protection control is also introduced to improve the safety performance of the motor controller. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0051] Figure 1 It is a flow chart of the control method of the motor controller of the present invention.

[0052] Figure 2 It is a schematic diagram of cutting the full speed range of the motor controller of the present invention into random speed intervals.

[0053] Figure 3 It is a schematic diagram of the generation process of the pulse control signal of the present invention.

[0054] Figure 4 It is a schematic diagram of PWM trigger current and electrical angle sampling of the present invention.

[0055] Figure 5 It is a schematic diagram of generating the SVPWM pulse control signal of the present invention.

[0056] Figure 6 It is a flow chart of the safety dead zone protection of the present invention.

[0057] Figure 7 It is a hardware topology diagram of the motor controller of the present invention.

[0058] Figure 8 It is a schematic diagram of the structure of the control device of the present invention. DETAILED DESCRIPTION

[0059] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below with reference to specific diagrams.

[0060] See also Figure 1 , the figure shows a control method of a motor controller, comprising the following steps:

[0061] Step S100, cutting the full speed range of the motor controller into a plurality of speed intervals, and cutting each speed interval into a plurality of random speed intervals;

[0062] Step S200, obtaining the current speed of the motor controller, and determining which random speed interval the current speed falls into;

[0063] Step S300, performing random number calculation processing on the random speed interval into which the current speed falls, and generating a random switching frequency for switching control of the motor controller;

[0064] Step S400, obtaining the current current value and the current electrical angle value of the motor controller, and generating an SVPWM pulse control signal according to the current current value, the current electrical angle value and the random switching frequency and in a fixed current loop period;

[0065] Step S500, limiting the safety dead time, and outputting the SVPWM pulse control signal according to the limiting result.

[0066] In step S100, see Figure 2 In this embodiment, the "Nine-Three" method is used for full speed range cutting. The full speed range of the motor controller is cut into 9 speed intervals, namely N1, N2...N9. Each speed interval N(x) is in (N(x-1), N(x-1)+Nmax / 9], and each speed interval is cut into 3 random speed intervals, that is, the N(x) interval (N(x-1), N(x-1)+Nmax / 9] is divided into 3 random speed intervals, such as C1, C2, and C3. Each segment of data is used as the input of the random algorithm to smoothly transition each speed stage and maintain control stability.

[0067] In step S300, the linear congruential method is used to calculate random numbers for the random speed interval that the current speed falls into, that is, the random frequency conversion period. The random numbers generated by the linear congruential method have a high degree of freedom, and the linear congruential method only includes one multiplication and one addition operation, which is easy to implement for the microprocessor. The calculation formula of the linear congruential method is:

[0068] x n+1 =Mod(a*x n +c,m)

[0069] o=x n+1 / m

[0070] y=(o+0.5)*t s

[0071] Among them, a is the multiplier, c is the increment, m is the modulus, t s is the center point.

[0072] See also Figure 3 In step S400, the current current value and the current electrical angle value of the motor controller are obtained, and an SVPWM pulse control signal is generated based on the current current value, the current electrical angle value and the random switching frequency and calculated in a fixed current loop period, including the following steps:

[0073] Step S401, calculating a random SVPWM period according to a fixed current loop period;

[0074] Step S402, calculating the IGBT switching time of the random SVPWM cycle;

[0075] Step S403, the PWM module channels x+1 and x+2 of the TC275 chip of the motor controller trigger the collection of the current current value and the current electrical angle value, such as Figure 4 As shown, the current current value and current electrical angle value of the motor controller are collected.

[0076] Step S404, the PWM module channel x+3 of the TC275 chip of the motor controller is triggered to generate a random SVPWM switching cycle;

[0077] Step S405, the complex PWM module channel random switching cycle is used as a base to generate an SVPWM pulse control signal, such as Figure 5 As shown, the control drives the IGBT to be turned on and off.

[0078] The motor controller can generate X+8 PWM signals by using the basic PWM as a reference point, of which X+1 and X+2 are used for current and angle sampling control, and X+3, X+4, X+5, X+6, X+7, and X+8 are used for 6-way switch control. In addition, the control calculation loop of the motor controller is constant and does not change with the switching frequency. The SVPWM triggering time is determined according to the cycle value of the application layer current loop. The PWM module channels x+1 and x+2 of the MCU are used to trigger the three-phase current value and electrical angle value acquisition to obtain the cycle value of the application layer current loop. The SVPWM trigger uses channels x+1 and x+2 to trigger at the same time, and uses a fixed value, which does not change with the change of the SVPWM random switch cycle calculation value.

[0079] See also Figure 6 In step S500, the safety dead time is limited, and the SVPWM pulse control signal is output according to the limit processing result, including the following steps:

[0080] Step S501, obtaining a current task and receiving an IGBT switch signal;

[0081] Step S502, determine whether the IGBT switching time is greater than 0μs and less than the time T that can change with the frequency, where the time T that can change with the frequency is 1 / F, F is the current jitter frequency, for example, the current jitter frequency F is 10khz, then the time T that can change with the frequency is 1 / (10*1000)s=100μs, if so, go to step S503, otherwise go to step S509;

[0082] Step S503, determine whether the closing time of the lower half bridge is greater than the opening time of the upper half bridge, whether the shut-down time of the upper half bridge is greater than the opening time of the lower half bridge, and whether the difference between the upper and lower half bridge times is less than the minimum protection time t1. If so, proceed to step S504;

[0083] Step S504, setting the lower half bridge shutdown time to the upper half bridge opening time minus the minimum protection time t1, and setting the lower half bridge opening time to the upper half bridge shutdown time plus the minimum protection time t1;

[0084] Step S505, determining whether the current duty cycle of the motor controller is less than the minimum allowable duty cycle, if so, proceeding to step S506, if not, proceeding to step S516;

[0085] Step S506, outputting the ASC mode;

[0086] Step S507, determining whether the current duty cycle of the motor controller is greater than the maximum allowable duty cycle, if so, proceeding to step S508, if not, proceeding to step S516;

[0087] Step S508, output the maximum allowable duty cycle, and proceed to step S516;

[0088] Step S509, determining whether the motor controller complies with the upper and lower ASC mode or the OC mode, if so, proceeding to step S510, if not, proceeding to step S516;

[0089] Step S510, determining whether the upper half bridge opening time is greater than the time T that can change with the frequency or whether the lower half bridge closing time is greater than the time T that can change with the frequency, if so, proceeding to step S511, if not, proceeding to step S513;

[0090] Step S511, determine whether the difference between the lower half bridge opening time and the upper half bridge closing time is less than the minimum protection time t1, if so, proceed to step S512, if not, proceed to step S516;

[0091] Step S512, set the lower half bridge opening time to the upper half bridge closing time plus the protection minimum time t1, and proceed to step S516;

[0092] Step S513, determining whether the upper half bridge shutdown time is greater than the time T that can change with the frequency or the lower half bridge opening time is greater than the time T that can change with the frequency, if so, proceeding to step S514, if not, proceeding to step S516;

[0093] Step S514, determine whether the difference between the upper half bridge opening time and the lower half bridge closing time is less than the minimum protection time t1, if so, proceed to step S515, if not, proceed to step S516;

[0094] Step S515, set the upper half bridge opening time to the lower half bridge closing time plus the protection minimum time t1, and proceed to step S516;

[0095] Step S516: output the SVPWM pulse control signal normally.

[0096] The motor controller can be classified according to the PWM output mode, which are normal working mode, upper half-bridge short-circuit mode, lower half-bridge short-circuit mode and open circuit mode. In each mode, the dead time can be guaranteed to ensure the safe and reliable output of the inverter. The pulse PWM duty calculated after normal frequency conversion is used as a dead time limit, and the direct leveling treatment below the minimum output time t0 is performed. The minimum and maximum duty cycle limit range is 4% to 96%. Based on the upper half-bridge short-circuit mode (upper ASC), lower half-bridge short-circuit mode (lower ASC), open circuit mode (OC), pulse control mode (PWMRUN) and other modes, the dead time of switching between the two modes is not less than the protection time t1. After the safety dead zone protection, the output is output to Figure 7 The hardware topology shown adopts single-tube parallel technology, reduces harmonics through hardware drive, improves motor high-frequency noise, improves motor controller efficiency, reduces electric vehicle NVH index, and provides comfort.

[0097] See also Figure 8 , the figure shows a control device for implementing the control method of the above-mentioned motor controller, including a speed cutting module 110, a speed judgment module 120, a random number calculation module 130, a pulse control signal generation module 140 and a safety dead zone protection module 150.

[0098] The speed cutting module 110 is used to cut the full speed range of the motor controller into a number of speed intervals, and to cut each speed interval into a number of random speed intervals.

[0099] The speed determination module 120 is used to obtain the current speed of the motor controller and determine which random speed interval the current speed falls into.

[0100] The random number calculation module 130 is used to perform random number calculation processing on the random speed interval that the current speed falls into, and generate a random switching frequency for the switching control of the motor controller.

[0101] The pulse control signal generating module 140 is used to obtain the current current value and the current electrical angle value of the motor controller, and generate an SVPWM pulse control signal according to the current current value, the current electrical angle value and the random switching frequency and in a fixed current loop period.

[0102] The safety dead zone protection module 150 is used to limit the safety dead zone time of the motor controller and output the SVPWM pulse control signal according to the limit processing result.

[0103] Each module in the control device of the present invention can be implemented in whole or in part by software, hardware, or a combination thereof. The above modules can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in a computer device in the form of software, so that the processor can call and execute operations corresponding to the above modules.

[0104] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A control method for a motor controller, characterized in that: The following steps are involved: Step S100, cutting the full speed range of the motor controller into a plurality of speed intervals, and cutting each speed interval into a plurality of random speed intervals; Step S200, obtaining the current speed of the motor controller, and determining which random speed interval the current speed falls into; Step S300, performing random number calculation processing on the random speed interval into which the current speed falls, and generating a random switching frequency for switching control of the motor controller; Step S400, obtaining a current current value and a current electrical angle value of the motor controller, and generating an SVPWM pulse control signal according to the current current value, the current electrical angle value and the random switching frequency and in a fixed current loop period; Step S500, limiting the safety dead time of the motor controller, and outputting the SVPWM pulse control signal according to the limiting processing result; In step S400, the current current value and the current electrical angle value of the motor controller are obtained, and an SVPWM pulse control signal is generated according to the current current value, the current electrical angle value and the random switching frequency and in a fixed current loop period, including the following steps: Step S401, calculating a random SVPWM period according to a fixed current loop period; Step S402, calculating the IGBT switching time of the random SVPWM cycle; Step S403, the PWM module channels x+1 and x+2 of the TC275 chip of the motor controller are used as reference triggers to collect the current current value and the current electrical angle value; Step S404, the PWM module channel x+3 of the TC275 chip of the motor controller is triggered to generate a random SVPWM switching cycle; Step S405 , the complex PWM module channel random switching cycle is used as a base to generate an SVPWM pulse control signal to control the on and off of the driving IGBT.

2. The control method of the motor controller according to claim 1, characterized in that: In step S100, the full speed range of the motor controller is divided into 9 speed intervals, and each speed interval is divided into 3 random speed intervals.

3. The control method of the motor controller according to claim 1, characterized in that: In step S300, a linear congruential method is used to perform random number calculation processing on the random speed interval into which the current speed falls, and the calculation formula is: x n+1 =Mod(a*x n +c,m) o=x n+1 / m y=(o+0.5)*t s Among them, a is the multiplier, c is the increment, m is the modulus, t s is the center point.

4. The control method of the motor controller according to claim 1, characterized in that: In step S500, the safety dead time of the motor controller is limited, and the SVPWM pulse control signal is output according to the limit processing result, including the following steps: Step S501, obtaining a current task and receiving an IGBT switch signal; Step S502, determining whether the IGBT switching time is greater than 0 μs and less than the time T that can vary with the frequency, if so, proceeding to step S503, otherwise proceeding to step S509; Step S503, determine whether the closing time of the lower half bridge is greater than the opening time of the upper half bridge, whether the shut-down time of the upper half bridge is greater than the opening time of the lower half bridge, and whether the difference between the upper and lower half bridge times is less than the minimum protection time t1. If so, proceed to step S504; Step S504, setting the lower half bridge shutdown time to the upper half bridge opening time minus the minimum protection time t1, and setting the lower half bridge opening time to the upper half bridge shutdown time plus the minimum protection time t1; Step S505, determining whether the current duty cycle of the motor controller is less than the minimum allowable duty cycle, if so, proceeding to step S506, if not, proceeding to step S516; Step S506, outputting the ASC mode; Step S507, determining whether the current duty cycle of the motor controller is greater than the maximum allowable duty cycle, if so, proceeding to step S508, if not, proceeding to step S516; Step S508, output the maximum allowable duty cycle, and proceed to step S516; Step S509, determining whether the motor controller complies with the upper and lower ASC mode or the OC mode, if so, proceeding to step S510, if not, proceeding to step S516; Step S510, determining whether the upper half bridge opening time is greater than the time T that can change with the frequency or whether the lower half bridge closing time is greater than the time T that can change with the frequency, if so, proceeding to step S511, if not, proceeding to step S513; Step S511, determine whether the difference between the lower half bridge opening time and the upper half bridge closing time is less than the minimum protection time t1, if so, proceed to step S512, if not, proceed to step S516; Step S512, set the lower half bridge opening time to the upper half bridge closing time plus the protection minimum time t1, and proceed to step S516; Step S513, determining whether the upper half bridge shutdown time is greater than the time T that can change with the frequency or the lower half bridge opening time is greater than the time T that can change with the frequency, if so, proceeding to step S514, if not, proceeding to step S516; Step S514, determine whether the difference between the upper half bridge opening time and the lower half bridge closing time is less than the minimum protection time t1, if so, proceed to step S515, if not, proceed to step S516; Step S515, set the upper half bridge opening time to the lower half bridge closing time plus the protection minimum time t1, and proceed to step S516; Step S516: output the SVPWM pulse control signal normally.

5. The control method of the motor controller according to claim 4, characterized in that: The time T that can change with the frequency is 1 / F, and F is the current jitter frequency.

6. A control device for implementing the control method of a motor controller according to any one of claims 1 to 5, characterized in that: include: A speed cutting module, the speed cutting module is used to cut the full speed range of the motor controller into several speed intervals, and cut each speed interval into several random speed intervals; A speed determination module, the speed determination module is used to obtain the current speed of the motor controller and determine which random speed interval the current speed falls into; A random number calculation module, the random number calculation module is used to perform random number calculation processing on the random speed interval into which the current speed falls, and generate a random switching frequency for switch control of the motor controller; A pulse control signal generating module, the pulse control signal generating module is used to obtain the current current value and the current electrical angle value of the motor controller, and generate an SVPWM pulse control signal according to the current current value, the current electrical angle value and the random switching frequency and in a fixed current loop period; as well as A safety dead zone protection module is used to limit the safety dead zone time of the motor controller and output the SVPWM pulse control signal according to the limit processing result.

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