Inductive coupling-based staggered modulation control method and device, and related equipment
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHANGSHA DANFINSWE ELECTRICAL TECH CO LTD
- Filing Date
- 2026-03-27
- Publication Date
- 2026-06-12
Smart Images
Figure CN121923518B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of power electronics technology, and in particular to an interleaved modulation control method, apparatus and related equipment based on inductive coupling. Background Technology
[0002] With the increasing diversification of power electronics applications and the continuous expansion of system capacity, the need to verify the control characteristics, load behavior, and system reliability of power electronic converters has become increasingly critical. In applications such as motor drives and power generation, traditional testing methods rely on building test platforms with real motors and mechanical loads. However, this physical prototype-based testing method has significant limitations: for example, complex mechanical load characteristics are difficult to reproduce accurately, high-power motors are bulky and expensive, and the cost of building and maintaining the entire test system is considerable. To address this, power electronic motor simulators capable of simulating the electrical characteristics of motors have emerged. These simulators typically consist of a "converter under test" (DUT) and a "simulation converter" used to simulate motor behavior. A digital controller controls the simulation converter to reproduce the electrical response of the target motor in real time.
[0003] To improve the simulation accuracy of motor simulators, analog converters are required to have extremely high current tracking bandwidth. One effective technique for increasing the equivalent control bandwidth is "asymmetric time-division frequency-multiplying interleaved modulation." This technique, without increasing the operating frequency of individual switching devices, achieves an n-fold increase in the overall equivalent control frequency of the system by interleaving the driving and independent duty cycle control of the switching transistors in each phase of an n-phase converter. This significantly enhances the dynamic response capability and tracking accuracy of the analog converter.
[0004] However, this existing technology has a significant drawback. Because the conduction time of each phase switch is independently controlled, and there is no direct electrical connection between phases, the current flowing through the inductors of each phase exhibits a significant amplitude imbalance when tracking a rapidly changing reference current. This current imbalance directly affects the total harmonic distortion of the analog converter's output current, reducing the simulation accuracy of the converter under test. Furthermore, under long-term operation, the power devices in the phase modules bearing higher current stress will age faster, thus compromising the long-term reliability of the entire motor simulator system. Therefore, how to effectively suppress multi-phase current imbalance while retaining the high bandwidth advantages of interleaved modulation has become a pressing technical problem to be solved in this field. Summary of the Invention
[0005] Based on the above problems, embodiments of the present invention provide a staggered modulation control method, device and related equipment based on inductive coupling. While maintaining a high equivalent control bandwidth based on staggered modulation, by introducing inductive coupling, the inter-phase current imbalance caused by independent control of the duty cycles of each phase is effectively suppressed, thereby improving the simulation accuracy and system reliability of the motor simulator.
[0006] In a first aspect, embodiments of the present invention provide a staggered modulation control method based on inductive coupling. This method is applied to a simulation converter in a motor simulator. The simulation converter is an n-phase interleaved coupled half-bridge converter, where n is an integer greater than 1, and any two-phase half-bridge circuits are coupled through an inductor; the method includes:
[0007] Obtain a reference current signal generated by the operation of the measured converter in the motor simulator; generate n drive signals with staggered phases and independently controllable duty cycles based on the difference between the reference current signal and the total inductor current of the simulation converter; where the switching period of each phase drive signal is the same, and the phase difference between adjacent two-phase drive signals is π / n, and the duty cycle of each phase drive signal is independently adjusted according to the difference; apply the n drive signals to the switching tubes of the corresponding n-phase half-bridges of the n-phase interleaved coupled half-bridge converter respectively, so that the simulation converter switches among 2n operating modes; where, within any switching period: when it is the period corresponding to the rising stage of the reference current signal, control the lower switching tubes of the n-phase half-bridges to conduct independently in sequence according to the staggered phases, the conduction duration of each phase lower switching tube is independently controllable, and only one phase's lower switching tube conducts at the same time, and the lower switching tubes of the remaining phases are turned off and the upper switching tubes conduct; through the inductive coupling effect between any two-phase half-bridge circuits, during the process of the total inductor current tracking the reference current signal, dynamically balance the n inductor currents of the n-phase half-bridges.
[0008] In a possible embodiment, any two-phase half-bridge circuits are coupled through an inductor with a coupling coefficient k, where -1 < k < 1; when k = 0, the n-phase interleaved coupled half-bridge converter is equivalent to an uncoupled structure; when k > 0, the inductors are positively coupled; when k < 0, the inductors are negatively coupled.
[0009] In a possible embodiment, during the process of the total inductor current tracking the reference current signal, through the inductive coupling effect, make the rising or falling slopes of the inductor currents flowing through each phase half-bridge correlated with each other, thereby suppressing the inter-phase current imbalance caused by independent adjustment of the duty cycles of each phase drive signal.
[0010] In a possible embodiment, applying the n drive signals to the switching tubes of the corresponding n-phase half-bridges of the n-phase interleaved coupled half-bridge converter respectively, so that the simulation converter switches among 2n operating modes, includes:
[0011] Within one switching cycle, it sequentially enters 2n operating modes;
[0012] In the (2m-1)th mode, only the lower switch of the m-th phase half-bridge is turned on, while the lower switches of the remaining n-1 phase half-bridges are turned off and the upper switches are turned on, where m is an integer from 1 to n;
[0013] In the 2mth mode, all lower switches of the phase half-bridge are turned off and all upper switches are turned on.
[0014] In one possible embodiment, based on the difference between the reference current signal and the total inductor current of the analog converter, n drive signals with interleaved phases and independently controllable duty cycles are generated, including:
[0015] The difference between the reference current signal and the total inductor current is input to the controller, and the controller outputs a total duty cycle signal.
[0016] The total duty cycle signal is decomposed and distributed to n carrier comparison channels with fixed interleaved phases to independently generate n drive signals with adjustable duty cycles.
[0017] In one possible embodiment, inductive coupling is achieved by placing mutual inductors between the independent inductors of each phase half-bridge, such that each phase inductor can be equivalent to a series or parallel combination of a leakage inductor and a decoupled mutual inductor.
[0018] In one possible embodiment, during any switching cycle: when the reference current signal decreases, the lower switches of the n phase half-bridges are controlled to turn off independently in staggered phases, and at the same time only the lower switch of one phase is turned off, while the lower switches of the other phases are turned on and the upper switches are turned off, and the inductor current of each phase is dynamically balanced through inductive coupling.
[0019] Secondly, embodiments of the present invention provide an interleaved modulation control device based on inductive coupling, applied to an analog converter in a motor simulator. The analog converter is an n-phase interleaved coupled half-bridge converter, where n is an integer greater than 1, and any two phases of the half-bridge circuit are inductively coupled. The device includes:
[0020] The acquisition module is used to acquire the reference current signal generated by the operation of the transducer under test in the motor simulator.
[0021] The generation module is used to generate n drive signals with staggered phases and independently controllable duty cycles based on the difference between the reference current signal and the total inductor current of the analog converter. Each phase drive signal has the same switching period, the phase difference between two adjacent phase drive signals is π / n, and the duty cycle of each phase drive signal is adjusted independently according to the difference.
[0022] The switching module is used to apply n drive signals to the switching transistors of the n phase half-bridges corresponding to the n phase interleaved half-bridge converter, so that the analog converter switches in 2n operating modes. In any switching cycle: during the period corresponding to the rising phase of the reference current signal, the lower switching transistors of the n phase half-bridges are controlled to turn on independently in staggered phases. The conduction duration of each phase lower switching transistor is independently controllable, and at the same time only the lower switching transistor of one phase is turned on, while the lower switching transistors of the other phases are turned off and the upper switching transistors are turned on.
[0023] The balancing module is used to dynamically balance the inductor currents of n phase half-bridges during the process of the total inductor current tracking the reference current signal through the inductive coupling between any two phase half-bridge circuits.
[0024] Thirdly, embodiments of the present invention provide a computer storage medium storing multiple instructions adapted for loading by a processor and executing the steps of the above-described method.
[0025] Fourthly, embodiments of the present invention provide an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, the computer program being adapted to be loaded by the processor and to execute the steps of the above-described method.
[0026] The beneficial effects of the technical solutions provided by some embodiments of the present invention include at least the following: by introducing the physical structure of inductive coupling and combining it with a time-division interleaved and independently controllable modulation strategy, the two goals of "high-bandwidth tracking" and "multiphase current balance" are unified. First, interleaved independent modulation is used to improve the equivalent control frequency and response speed of the system. Then, the natural physical characteristics of the coupled inductor are used to correct the current imbalance that may be caused by independent control in real time and automatically. Ultimately, a complete and high-performance motor simulator current control scheme is formed, effectively solving the core problem of the difficulty in achieving both accuracy and reliability in existing asymmetric interleaved modulation technology. While ensuring high-precision simulation, the long-term operational reliability of the system is significantly improved. Attached Figure Description
[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0028] Figure 1 An exemplary framework diagram of a motor simulator is provided for embodiments of the present invention;
[0029] Figure 2A flowchart illustrating the interleaved modulation control method based on inductive coupling provided in an embodiment of the present invention;
[0030] Figure 3 This is a topology diagram of an n-phase interleaved coupled half-bridge converter provided in an embodiment of the present invention;
[0031] Figure 4 This is a decoupling equivalent circuit for an n-phase half-bridge interleaved circuit based on coupled inductors provided in an embodiment of the present invention;
[0032] Figure 5 A block diagram of current tracking control for an n-phase half-bridge interleaved circuit based on coupled inductors provided by the present invention;
[0033] Figure 6 A structural block diagram of an interleaved modulation control device based on inductive coupling provided in an embodiment of the present invention;
[0034] Figure 7 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation
[0035] To make the features and advantages of the present invention more apparent and understandable, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0036] In the following description, when referring to the accompanying drawings, the same numbers in different drawings denote the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatuses and methods consistent with some aspects of the invention as detailed in the appended claims.
[0037] In the description of this invention, it should be understood that the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances. Furthermore, in the description of this invention, unless otherwise stated, "multiple" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.
[0038] As mentioned earlier, to accurately reproduce the dynamic electrical response of a motor, the core requirement is that the analog converter possesses extremely high current tracking bandwidth. An advanced control strategy is "asymmetric time-division multiplexing interleaved modulation" technology. This technology employs a multi-phase (n-phase) parallel converter topology. By interleaving the phases of the drive signals for each phase (with a phase difference of π / n) and independently controlling the duty cycle of each phase, the overall equivalent control frequency of the system can be increased to n times the original without increasing the operating frequency of individual power switches. This significantly expands the control bandwidth and improves the analog converter's ability to track rapidly changing reference currents. However, while this existing technology increases bandwidth, it also introduces a new critical problem. Because the conduction time (duty cycle) of each phase switch is completely independently controlled, and the inductances between phases are physically and electrically isolated, a severe imbalance in the inductor currents of each phase occurs during dynamic tracking. This imbalance directly increases the ripple and harmonic distortion of the total output current, reducing simulation accuracy and causing test results to deviate from actual operating conditions. Furthermore, uneven current stress leads to inconsistent heating and aging processes in power devices (such as SiC MOSFETs) across phases, reducing overall system reliability and potentially causing single-phase failures over long-term operation. Therefore, effectively suppressing or eliminating multi-phase current imbalance while retaining the high bandwidth advantage of "time-division multiplexing interleaved modulation" has become a core bottleneck restricting the further application of this technology in high-precision motor simulators.
[0039] In view of this, the present invention provides an interleaved modulation control method, apparatus, and related equipment based on inductive coupling. An inductive coupling mechanism is introduced into an n-phase interleaved half-bridge converter, so that the inductors between any two phases are no longer independent, but are interconnected through a specific coupling coefficient (k). Based on this coupled topology, and combined with an improved modulation control method, high-bandwidth current tracking can be achieved while dynamically balancing the currents of each phase using the physical characteristics of the coupled inductors. This not only solves the contradiction between accuracy and reliability in existing technologies, but also provides a new and effective solution for highly reliable power electronic motor simulation.
[0040] Please see Figure 1 , Figure 1 An exemplary framework diagram of a motor simulator is provided for embodiments of the present invention. For example... Figure 1As shown, the motor simulator mainly consists of two parts: the Device Under Test (DUT) and the Emulator Converter. These two parts are connected via a power circuit to form a closed test loop. The DUT, as the object under test, is typically a motor drive or power conversion device used in real-world applications, such as an inverter. During operation, it generates corresponding output current or voltage signals, which serve as the reference current signal for the entire simulator system. The Emulator Converter employs a multiphase power electronic converter topology; in this embodiment, it is an n-phase interleaved coupled half-bridge structure. Its core function is to simulate the electrical behavior of a real motor. Sensors collect the actual output current of the DUT and send it as a reference current signal to the Emulator Converter's controller. On the Emulator Converter side, a current sensor detects its total inductance current. The controller compares this current with the reference current to obtain a current error signal. This current error signal is processed by the controller (usually a proportional-integral or more complex controller) to generate the overall duty cycle command. This command is then processed by the core inductively coupled time-division multiplexing interleaved modulation module of this solution, ultimately generating n PWM drive signals with specific interleaved phases and independently controllable duty cycles. These n PWM signals are applied to the power switches of the n phase half-bridges of the analog converter, controlling their on / off states, thereby precisely adjusting the total inductor current to track changes in the reference current in real time.
[0041] In summary, Figure 1 The motor simulator shown is a "hardware-in-the-loop" test platform: the converter under test is like driving a real motor, while the simulated converter plays the role of a "virtual motor". It dynamically reproduces the current response of the motor through power electronics, so as to complete a comprehensive and flexible test of the performance of the converter under test without using a real motor and mechanical load.
[0042] Please see Figure 2 , Figure 2 This is a flowchart illustrating an inductively coupled interleaved modulation control method provided in an embodiment of the present invention. The execution entity of this embodiment can be an electronic device executing the inductively coupled interleaved modulation control, a processor within the electronic device executing the inductively coupled interleaved modulation control method, or an inductively coupled interleaved modulation control service within the electronic device executing the inductively coupled interleaved modulation control method. For ease of description, the following uses a processor within an electronic device as an example to describe the specific execution process of the inductively coupled interleaved modulation control method.
[0043] like Figure 2 As shown, the interleaved modulation control method based on inductive coupling can include at least:
[0044] S201. Obtain the reference current signal generated by the operation of the converter under test in the motor simulator.
[0045] Specifically, the method is applied to an analog converter in a motor simulator. The analog converter is an n-phase interleaved coupled half-bridge converter, where n is an integer greater than 1, such as 2, 3, 4, or 6. The core feature of this converter is that any two phases of the half-bridge circuit are coupled in a specific way through inductors, rather than using completely independent inductors as in traditional interleaved parallel topologies. For example, with n=3, a three-phase interleaved coupled half-bridge converter is formed. In a hardware-in-the-loop test platform consisting of the converter under test (e.g., a three-phase inverter), a filter network (the resistor R and inductor L of the simulated motor windings), and the analog converter, the converter under test operates under actual or simulated control logic, outputting a PWM voltage. This voltage is applied to the RL filter network, generating a corresponding current. A high-precision current sensor, such as a Hall effect current sensor or a sampling resistor in conjunction with an isolated operational amplifier, is used to collect the current flowing through the filter network in real time, and this current signal is used as a reference current signal. This reference current signal accurately reflects the output behavior of the converter under test when driving a load (simulated motor) with a specific impedance, and is the target that the analog converter needs to accurately track.
[0046] In one possible implementation, please refer to Figure 3 , Figure 3 The topology diagram of the n-phase interleaved coupled half-bridge converter provided in the embodiments of the present invention is as follows: Figure 3 As shown, this converter is selected as the analog converter. This topology consists of n SiC phase half-bridges, each phase half-bridge is composed of two SiC MOSFETs, and any two phases are coupled through an inductor with a coefficient k. Therefore, the voltage across the current transformer Lm and the voltage across the inductor can be expressed as follows:
[0047]
[0048] In the formula, i and j are algebras, where i and j are any integers between 1 and n. k is the coupling coefficient, where -1 < k < 1. When k is 0, it is non-coupled; when k is greater than 0, it is positive coupling; when k is less than 0, it is negative coupling. The coupling coefficient k is a physical parameter that characterizes the tightness of the magnetic flux linkage between two inductors. In specific implementation, the value of k can be precisely controlled by designing the structure of the magnetic component. For example, by winding multiple inductor windings on the same magnetic core (such as E-type, PQ-type or toroidal magnetic core), and by adjusting the distance between windings, relative positions or using sectional winding techniques, the desired value of k can be obtained, and its range is between 0 and close to 1 (positive coupling). If negative coupling (k < 0) is required, the winding can be wound in the reverse direction. When k = 0, it means there is no mutual inductance between the inductors, and at this time the n-phase interleaved coupled half-bridge converter degenerates (equivalent) into a traditional non-coupled interleaved parallel structure. When k > 0, it is positive coupling. At this time, an increase in the current of one phase will induce an electromotive force in the coupled-phase inductor that hinders its increase, making the current change tend to be smooth and synchronous. When k < 0, it is negative coupling, and the acting direction of the induced electromotive force is opposite. Setting the coupling coefficient k within the range of (-1, 1) is to cover all physically meaningful coupling cases. Preferably, the value range of k can be between 0.1 and 0.9 to achieve a significant current balancing effect. By precisely designing and selecting the coupling coefficient k, the dynamic response and steady-state balancing performance of the system can be optimized. For example, moderate positive coupling (such as k = 0.5) can provide good current balancing ability without significantly reducing the system response speed.
[0049] Furthermore, the inductive coupling is achieved by setting an instrument transformer between the independent inductors of each phase half-bridge, so that each phase inductor can be equivalently a series or parallel combination of a leakage inductance and a decoupled mutual inductance. Specifically, there are two preferred implementation methods: Method 1 (integrated magnetic core structure): Use a multi-winding integrated magnetic component. For example, use a common magnetic core (such as toroidal or E-type magnetic core) with n symmetric windings. Each winding is connected to a phase half-bridge and serves as the filtering or energy storage inductor for that phase. Since the windings share the same magnetic path, there is naturally a strong mutual inductance between them, achieving coupling. By designing the number of turns of the windings, relative positions and magnetic core air gaps, the self-inductance and mutual inductance values (i.e., L and k) can be precisely controlled. Method 2 (discrete inductors plus external instrument transformer): Use an independent inductor for each phase, and then connect an additional, low-power instrument transformer between any two independent inductors to associate their magnetic fields. Regardless of which method is used, its electrical effect can be described by an equivalent circuit. Please refer to Figure 4 , Figure 4 which is the decoupled equivalent circuit of the n-phase half-bridge interleaved circuit based on coupled inductors provided by the embodiment of the present invention. As shown in Figure 4 , the expression for the leakage inductance is obtained as:
[0050]
[0051] In the formula, L ki For inductor L i The leakage inductance. Furthermore, it is worth noting that when k is 0, the n-phase interleaved coupled half-bridge converter can be equivalent to a traditional uncoupled n-phase interleaved coupled half-bridge converter. Therefore, the traditional uncoupled n-phase interleaved coupled half-bridge converter can be considered a special case of the n-phase interleaved coupled half-bridge converter.
[0052] S202. Based on the difference between the reference current signal and the total inductor current of the analog converter, generate n drive signals with staggered phases and independently controllable duty cycles.
[0053] Specifically, please refer to Figure 5 , Figure 5 The current tracking control block diagram of the n-phase half-bridge interleaved circuit based on coupled inductors provided by this invention is as follows: Figure 5 As shown, this control method enables real-time tracking of the analog converter's inductor current against a reference current from the converter under test. The total output current of the analog converter, i.e., the total inductor current, is acquired in real time using another set of current sensors. The acquired reference current signal and the total inductor current are fed into a subtractor in a digital controller (such as a DSP or FPGA) to obtain a current error signal (e = reference current signal - total inductor current). This error signal is processed by a control algorithm (e.g., a proportional-integral controller) to output a total duty cycle command reflecting the global current demand. Then, through an interleaved modulation logic, this total duty cycle command is decomposed and distributed to n phase-differentiated modulation channels. Each channel independently compares its assigned duty cycle command with a sawtooth or triangular wave carrier wave with a fixed phase, thereby generating a PWM drive signal. Therefore, these n drive signals have the same switching period, adjacent signals are strictly interleaved in phase, and the duty cycle (i.e., pulse width) of each signal can be independently adjusted according to the allocation result of the total duty cycle command, thus achieving fine, high-frequency control of the total current.
[0054] In one specific implementation, the difference between the reference current signal and the total inductor current is input to a controller. This controller can be a proportional-integral (PI) controller, a proportional-resonant (PR) controller, or a more complex predictive controller within a digital signal processor (DSP). After processing the current error signal, the controller outputs a total duty cycle signal. Subsequently, the total duty cycle signal is decomposed and distributed to n carrier comparison channels with fixed interleaved phases. Specifically, one of the following two preferred implementation methods can be used: Method 1: A duty cycle allocation calculation unit is set up in the FPGA or DSP. This unit decomposes D_total into n independent phase duty cycle instructions according to a certain algorithm (such as average allocation plus current sharing compensation). Simultaneously, n triangular carriers with sequentially lagging phases are generated. Each phase duty cycle instruction is compared with the in-phase triangular carrier in a digital comparator. When the instruction value is greater than the carrier value, a high level is output (driving the lower transistor); otherwise, a low level is output (driving the upper transistor), thus independently generating each PWM channel. Method 2: The total duty cycle signal is directly used as the modulation signal, and simultaneously fed into n parallel comparators. The other end of each comparator receives a phase-interleaved (2π / n) triangular carrier. By setting different carrier offsets, the duty cycle is effectively interleaved along the time axis.
[0055] S203. Apply the n drive signals to the switching transistors of the n phase half-bridges corresponding to the n-phase interleaved half-bridge converter, so that the analog converter switches between 2n operating modes.
[0056] Specifically, the generated n PWM signals, after being amplified and isolated by the drive circuit, control the upper and lower switches of the n phase half-bridges respectively. Within one switching cycle, when the reference current signal rises and requires an increase in the total inductor current, the system controls the lower switches of the n phase half-bridges to conduct sequentially for a period of time according to their inherent staggered phase order. At any given moment, only the lower switch of one phase is on, while the lower switches of the remaining (n-1) phases are off and the upper switches are on. By independently adjusting the conduction duration (duty cycle) of each phase's lower switch, the rate of current rise can be precisely controlled. This control method naturally divides one switching cycle into 2n different circuit operating states. In one specific implementation, firstly, the system sequentially enters 2n operating modes within one switching cycle. These 2n modes are periodically repeated. Specifically, in the (2m-1)th mode (where m is an integer from 1 to n, taking values sequentially), only the lower switch of the m-th phase half-bridge is on, while all the lower switches of the remaining n-1 phase half-bridges are off and their upper switches are on. For example, when m=1, it is the first mode, and phase L1 is the lower switch S. L1,L On, switch S L1,H When the circuit is off, all other phases are switched on by the upper switch and switched off by the lower switch; when m=2, it is the third mode, and only phase L2 is switched off by the lower switch S.L2,L On, switch S L2,H When the circuit is turned off, all other phases have their upper switches on and lower switches off, and so on until the (2n-1)th mode. Then, in the 2mth mode, all the lower switches of the n-phase half-bridge are turned off, and their upper switches are turned on. For example, the 2nd, 4th, ..., 2nth modes are like this. Taking n=3 as an example, 6 modes will be experienced sequentially in one switching cycle: Mode 1 (only P1 lower switch is on), Mode 2 (all upper switches are on), Mode 3 (only P2 lower switch is on), Mode 4 (all upper switches are on), Mode 5 (only P3 lower switch is on), Mode 6 (all upper switches are on). The duration of each mode is determined by the duty cycle of the corresponding phase. In the first mode, phase L1 is the lower switch S. L1,L On, switch S L1,H When the circuit is turned off, the state-space equations for the inductor currents are as follows:
[0057]
[0058] In the formula, V in Represents the port input voltage, V o This represents the port output voltage. Therefore, the slopes of the currents in each inductor can be defined as follows:
[0059]
[0060] In the formula, f L1,I f L2,I f Ln,I and f L,I During the operation in Mode I, the inductor current i in phase L1 is respectively... L1 L2 phase inductor current i L2 L n Phase inductor current i Ln and total input current i L The current slope. Due to the input voltage V in With output voltage V o Since they are equal, the slopes of the currents in each inductor are:
[0061]
[0062] Therefore, the total inductor current iL at time t1 can be obtained as:
[0063]
[0064] In the formula, i L For inductor current, i L (t0) and i L (t1) represents the total inductor current at times t0 and t1, respectively. D1 is the value of the switch S under phase L1. L1,LDuty cycle. T S The switching cycle.
[0065] In the second mode, all lower switches of the n-phase half-bridge interleaved circuit are turned off, and the upper switches are turned on. Based on Kirchhoff's laws, the state-space equations for the inductor currents in the second mode are:
[0066]
[0067] Due to the input voltage V in With output voltage V o Since they are equal, the slopes of the currents in each inductor can be represented as follows:
[0068]
[0069] In the formula, f L1,II f L2,II f Ln,II and f L,II During the second mode operation, the L1 phase inductor current i L1 L2 phase inductor current i L2 L n Phase inductor current i Ln and total input current i L The current slope. From the above equation, it can be seen that the current of each inductor remains constant during the second mode. Furthermore, since each phase half-bridge circuit is symmetrical, the operating principle of the n-phase interleaved coupled half-bridge converter in any 2m modes is the same.
[0070] In the third mode, only phase L2 of the n-phase half-bridge interleaved circuit is the lower switch S. L2,L On, switch S L2,H When the circuit is off, all other phases have the upper switch on and the lower switch off. Based on Kirchhoff's laws, the state-space equations for the inductor currents in the third mode are:
[0071]
[0072] Therefore, the slopes of the currents in each inductor can be represented as follows:
[0073]
[0074] In the formula, f L1,III f L2,III f Ln,III and f L,III During the third mode operation, the L1 phase inductor current i L1 L2 phase inductor current i L2 L n Phase inductor current i Lnand total input current i L The slope of the current.
[0075] Therefore, the total inductance current i can be obtained. L At time t3:
[0076]
[0077] In the formula, i L (t2) and i L (t3) represents the total inductor current at times t2 and t3, respectively. D2 is the value of switch S under phase L2. L2,L Duty cycle.
[0078] In the 2n-1th mode, the n-phase half-bridge interleaved circuit has only L n Phase is the lower switch S Ln,L On, switch S Ln,H When the circuit is off, all other phases have the upper switch on and the lower switch off. Based on Kirchhoff's laws, the state-space equations for the inductor currents in the (2n-1)th mode are as follows:
[0079]
[0080] Therefore, the slopes of the currents in each inductor can be represented as follows:
[0081]
[0082] In the formula, f L1,2n-1 f L2,2n-1 f L(n-1),2n-1 f Ln,2n-1 and f L,2n-1 The L1 phase inductor current i during the (2n-1)th mode operation is respectively... L1 L2 phase inductor current i L2 L n-1 Phase inductor current i L(n-1) L n Phase inductor current i Ln and total input current i L The slope of the current.
[0083] In summary, the change in current of each inductor during the rise of iref over one switching cycle TS is:
[0084]
[0085] During the period when the reference current signal is decreasing, the waveforms of the key parameters of the n-phase interleaved half-bridge converter based on the asymmetric interleaved time-division frequency multiplication modulation method using coupled inductors are opposite to those during the period when the reference current signal is increasing. This embodiment will not elaborate further on this.
[0086] S204. Through the inductive coupling between any two phase half-bridge circuits, the n inductor currents of the n phase half-bridges are dynamically balanced during the process of the total inductor current tracking the reference current signal.
[0087] Specifically, due to coupling between the inductors of each phase, when the current in one phase attempts to change rapidly due to the conduction of its lower transistor, the changing magnetic field induces an electromotive force (EMF) in the inductors of other phases through mutual inductance. This EMF either hinders or promotes the change in current in other phases. This physical mutual restraint makes the rising or falling slopes of the current in each phase no longer completely independent, but interconnected. Even if there are differences in the duty cycles of the drive signals of each phase, the coupling effect can automatically suppress the resulting current amplitude deviation, forcing the currents in each phase to tend towards equilibrium. In one possible implementation, during the dynamic process of the total inductor current tracking the reference current, when the system uses independent duty cycle control, it is assumed that due to control errors or slight asymmetry in circuit parameters, the duty cycle allocated to the m-th phase is slightly larger, and its theoretical current rising slope will be higher than that of other phases. In a conventional topology without coupling, this would directly lead to the current amplitude of this phase gradually becoming higher than that of other phases, causing imbalance. However, in the coupled topology of this invention, when the current of phase m attempts to rise at a higher slope, due to the presence of mutual inductance, its rapidly changing current induces a voltage on the inductors of other coupled phases (such as phase j). According to Lenz's law, this induced voltage tends to reduce the difference between the rate of change of the current of phase j and the current of phase m. Mathematically, coupling makes the set of differential equations describing the currents of each phase interconnected; the derivatives (i.e., slopes) of the currents of each phase are no longer independent, but are interconnected through a matrix containing the coupling coefficient k. The system automatically finds an equilibrium point such that, while satisfying the total current change requirement (determined by the total duty cycle), the rate of change of the currents of each phase are mutually adjusted, ultimately suppressing any abnormally rapid increase or decrease in the current of any phase.
[0088] This invention provides an interleaved modulation control method based on inductive coupling. By introducing the physical structure of inductive coupling and combining it with a time-division interleaved and independently controllable modulation strategy, the method achieves a balance between the two objectives of "high-bandwidth tracking" and "multiphase current balance." First, interleaved independent modulation is used to improve the system's equivalent control frequency and response speed. Then, the natural physical characteristics of the coupled inductor are used to correct the current imbalance that may be caused by independent control in real time and automatically. This ultimately forms a complete, high-performance motor simulator current control scheme, effectively solving the core problem of the difficulty in achieving both accuracy and reliability in existing asymmetric interleaved modulation techniques. While ensuring high-precision simulation, it significantly improves the long-term operational reliability of the system.
[0089] Please see Figure 6 , Figure 6This is a structural block diagram of an interleaved modulation control device based on inductive coupling, provided as an embodiment of the present invention. Figure 6 As shown: The interleaved modulation control device 600 based on inductive coupling includes: an acquisition module 610, a generation module 620, a switching module 630, and a balancing module 640, wherein:
[0090] The acquisition module 610 is used to acquire the reference current signal generated by the operation of the transducer under test in the motor simulator;
[0091] The generation module 620 is used to generate n drive signals with staggered phases and independently controllable duty cycles based on the difference between the reference current signal and the total inductor current of the analog converter; wherein, the switching period of each phase drive signal is the same, the phase difference between two adjacent phase drive signals is π / n, and the duty cycle of each phase drive signal is adjusted independently according to the difference.
[0092] The switching module 630 is used to apply n drive signals to the switching transistors of the n phase half-bridges corresponding to the n phase interleaved half-bridge converter, so that the analog converter switches in 2n operating modes. In any switching cycle: when the reference current signal rises, the lower switching transistors of the n phase half-bridges are controlled to turn on independently in staggered phases. The conduction duration of each phase lower switching transistor is independently controllable. At any given time, only the lower switching transistor of one phase is turned on, while the lower switching transistors of the other phases are turned off and the upper switching transistors are turned on.
[0093] The balancing module 640 is used to dynamically balance the inductor currents of n phase half-bridges during the process of the total inductor current tracking the reference current signal through the inductive coupling between any two phase half-bridge circuits.
[0094] It should be noted that the inductively coupled interleaved modulation control device provided in the above embodiments is only illustrated by the division of the functional modules described above when executing the inductively coupled interleaved modulation control method. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. In addition, the inductively coupled interleaved modulation control device and the inductively coupled interleaved modulation control method embodiments provided in the above embodiments belong to the same concept, and the implementation process is detailed in the method embodiments, which will not be repeated here.
[0095] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.
[0096] Please see Figure 7 , Figure 7 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Figure 7As shown, the electronic device 700 may include: at least one processor 701, at least one network interface 704, a user interface 703, a memory 705, and at least one communication bus 702.
[0097] The communication bus 702 is used to enable communication between these components.
[0098] The user interface 703 may include a display screen, and the optional user interface 703 may include a standard wired interface or a wireless interface.
[0099] The network interface 704 may optionally include a standard wired interface or a wireless interface (such as a Wi-Fi interface).
[0100] The processor 701 may include one or more processing cores. The processor 701 connects to various parts within the electronic device 700 using various interfaces and lines, and performs various functions and processes data by running or executing instructions, programs, code sets, or instruction sets stored in the memory 705, and by calling data stored in the memory 705. Optionally, the processor 701 may be implemented using at least one hardware form of Digital Signal Processing (DSP), Field-Programmable Gate Array (FPGA), or Programmable Logic Array (PLA). The processor 701 may integrate one or a combination of several of the following: Central Processing Unit (CPU), Graphics Processing Unit (GPU), and modem. The CPU primarily handles the operating system, user interface, and applications; the GPU is responsible for rendering and drawing the content required for display; and the modem handles wireless communication. It is understood that the modem may also not be integrated into the processor 701 and may be implemented as a separate chip.
[0101] The memory 705 may include random access memory (RAM) or read-only memory. Optionally, the memory 705 may include a non-transitory computer-readable storage medium. The memory 705 can be used to store instructions, programs, code, code sets, or instruction sets. The memory 705 may include a program storage area and a data storage area, wherein the program storage area may store instructions for implementing an operating system, instructions for at least one function (such as touch function, sound playback function, image playback function, etc.), instructions for implementing the above-described method embodiments, etc.; the data storage area may store data involved in the above-described method embodiments, etc. Optionally, the memory 705 may also be at least one storage device located remotely from the aforementioned processor 701. Figure 7 As shown, the memory 705, which serves as a computer storage medium, may include an operating system, a network communication module, a user interface module, and an interleaved modulation control application based on inductive coupling.
[0102] exist Figure 7 In the illustrated electronic device 700, the user interface 703 is mainly used to provide an input interface for the user and acquire user input data; while the processor 701 can be used to call the inductively coupled interleaved modulation control application stored in the memory 705, and specifically perform the following operations: acquire the reference current signal generated by the operation of the converter under test in the motor simulator; generate n drive signals with interleaved phases and independently controllable duty cycles based on the difference between the reference current signal and the total inductance current of the analog converter; wherein, the switching period of each phase drive signal is the same, the phase difference between two adjacent phase drive signals is π / n, and the duty cycle of each phase drive signal is independently controllable based on the difference. The system adjusts the switching transistors of the n phase half-bridges corresponding to the n-phase interleaved half-bridge converter by applying n drive signals to each phase half-bridge, enabling the analog converter to switch between 2n operating modes. Within any switching cycle: during the period corresponding to the rising phase of the reference current signal, the lower switches of the n phase half-bridges are controlled to turn on independently in staggered phases. The conduction duration of each phase's lower switch is independently controllable, and at any given moment, only one phase's lower switch is on, while the lower switches of the remaining phases are off and the upper switches are on. Through the inductive coupling between any two phase half-bridge circuits, the n inductor currents of the n phase half-bridges are dynamically balanced during the process of the total inductor current tracking the reference current signal.
[0103] In some possible embodiments, any two-phase half-bridge circuits are coupled by an inductor with a coupling coefficient k, where -1 < k < 1; when k = 0, the n-phase interleaved coupled half-bridge converter is equivalent to an uncoupled structure; when k > 0, the inductors are positively coupled; when k < 0, the inductors are negatively coupled.
[0104] In some possible embodiments, during the process of the total inductor current tracking the reference current signal, through the inductor coupling effect, the rising or falling slopes of the inductor currents flowing through each phase half-bridge are correlated with each other, thereby suppressing the inter-phase current imbalance caused by the independent adjustment of the duty cycles of the driving signals of each phase.
[0105] In some possible embodiments, the processor 701 executes to apply n driving signals to the switching tubes of the n corresponding phase half-bridges of the n-phase interleaved coupled half-bridge converter respectively, so that the analog converter switches among 2n operating modes, and is specifically used to execute:
[0106] Within one switching period, sequentially enter 2n operating modes in a cycle;
[0107] In the (2m - 1)-th mode, only the lower switching tube of the m-th phase half-bridge is turned on, and the lower switching tubes of the remaining n - 1 phase half-bridges are turned off and the upper switching tubes are turned on, where m is an integer from 1 to n;
[0108] In the 2m-th mode, the lower switching tubes of all phase half-bridges are turned off and the upper switching tubes of all phase half-bridges are turned on.
[0109] In some possible embodiments, the processor 701 executes to generate n driving signals with interleaved phases and independently controllable duty cycles according to the difference between the reference current signal and the total inductor current of the analog converter, and is specifically used to execute:
[0110] Input the difference between the reference current signal and the total inductor current into a controller, and the controller outputs a total duty cycle signal;
[0111] The total duty cycle signal is decomposed and distributed to n carrier comparison channels with fixed interleaved phases to independently generate n driving signals with adjustable duty cycles.
[0112] In some possible embodiments, the inductor coupling is realized by setting an instrument transformer between the independent inductors of each phase half-bridge, so that each phase inductor can be equivalently a series or parallel combination of a leakage inductance and a decoupled mutual inductance.
[0113] In some possible embodiments, within any switching period: when the reference current signal drops, control the lower switching tubes of the n phase half-bridges to turn off independently in sequence according to the interleaved phases, and at the same time only the lower switching tube of one phase is turned off, and the lower switching tubes of the remaining phases are turned on and the upper switching tubes are turned off, and dynamically balance the inductor currents of each phase through the inductor coupling effect.
[0114] This invention also provides a computer-readable storage medium storing instructions that, when executed on a computer or processor, cause the computer or processor to perform the above-described instructions. Figure 2 One or more steps in the illustrated embodiment. If the constituent modules of the above-described inductively coupled interleaved modulation control device are implemented as software functional units and sold or used as independent products, they can be stored in the computer-readable storage medium.
[0115] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially as a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of the present invention are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted through the computer-readable storage medium. The computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible to a computer or a data storage device such as a server or data center that integrates one or more available media. The available media may be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., digital versatile discs (DVDs)), or semiconductor media (e.g., solid state disks (SSDs)).
[0116] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. This program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. The aforementioned storage medium includes various media capable of storing program code, such as read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks. Unless otherwise specified, the technical features of this embodiment and its implementation schemes can be combined arbitrarily.
[0117] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A method for interleaved modulation control based on inductive coupling, characterized in that, The method is applied to a simulation converter in a motor simulator. The simulation converter is an n-phase interleaved coupled half-bridge converter, where n is an integer greater than 1, and any two-phase half-bridge circuits are coupled through inductors. The method includes: Obtaining a reference current signal generated by the operation of the converter under test in the motor simulator; Generating n driving signals with interleaved phases and independently controllable duty cycles according to the difference between the reference current signal and the total inductor current of the simulation converter; wherein, the switching period of each driving signal is the same, the phase difference between adjacent two-phase driving signals is π / n, and the duty cycle of each phase driving signal is independently adjusted according to the difference; Applying the n driving signals to the switching tubes of the corresponding n-phase half-bridges of the n-phase interleaved coupled half-bridge converter respectively, so that the simulation converter switches among 2n operating modes; Wherein, within any switching period: when it is the time period corresponding to the rising stage of the reference current signal, controlling the lower switching tubes of the n-phase half-bridges to conduct independently in sequence according to the interleaved phases, the conduction duration of the lower switching tubes of each phase is independently controllable, and only one phase's lower switching tube conducts at the same time, and the lower switching tubes of the remaining phases are turned off and the upper switching tubes are turned on; Through the inductive coupling effect between any two-phase half-bridge circuits, during the process of the total inductor current tracking the reference current signal, dynamically balancing the n inductor currents of the n-phase half-bridges.
2. The interleaved modulation control method based on inductive coupling according to claim 1, characterized in that, Any two-phase half-bridge circuits are coupled through an inductor with a coupling coefficient k, where -1 < k < 1; when k = 0, the n-phase interleaved coupled half-bridge converter is equivalent to an uncoupled structure; when k > 0, the inductors are in positive coupling; when k < 0, the inductors are in negative coupling.
3. The interleaved modulation control method based on inductive coupling according to claim 1, characterized in that, During the process of the total inductor current tracking the reference current signal, through the inductive coupling effect, making the rising or falling slopes of the inductor currents flowing through each phase half-bridge correlated with each other, so as to suppress the inter-phase current imbalance caused by the independent adjustment of the duty cycles of each phase driving signal.
4. The interleaved modulation control method based on inductive coupling according to claim 1, characterized in that, The applying the n driving signals to the switching tubes of the corresponding n-phase half-bridges of the n-phase interleaved coupled half-bridge converter respectively, so that the simulation converter switches among 2n operating modes, includes: Within one switching period, sequentially entering 2n operating modes in a cycle; In the (2m - 1)th mode, only the lower switching tube of the mth phase half-bridge conducts, and the lower switching tubes of the remaining n - 1 phase half-bridges are turned off and the upper switching tubes are turned on, where m is an integer from 1 to n; In the 2mth mode, the lower switching tubes of all phase half-bridges are turned off and the upper switching tubes of all phase half-bridges are turned on.
5. The interleaved modulation control method based on inductive coupling according to claim 1, characterized in that, The generating n driving signals with interleaved phases and independently controllable duty cycles according to the difference between the reference current signal and the total inductor current of the simulation converter, includes: Inputting the difference between the reference current signal and the total inductor current into a controller, and the controller outputs a total duty cycle signal; The total duty cycle signal is decomposed and distributed to n carrier comparison channels with fixed interleaved phases to independently generate the n duty cycle adjustable driving signals.
6. The interleaved modulation control method based on inductive coupling according to claim 1, characterized in that, The inductive coupling is achieved by setting mutual inductors between the independent inductors of each phase half-bridge, so that each phase inductor can be equivalent to a series or parallel combination of a leakage inductor and a decoupled mutual inductor.
7. The interleaved modulation control method based on inductive coupling according to claim 1 or 4, characterized in that, During any switching cycle: when the reference current signal decreases, the lower switching transistors of the n phase half-bridges are controlled to turn off independently in sequence according to the staggered phases, and at the same time only the lower switching transistor of one phase is turned off, while the lower switching transistors of the other phases are turned on and the upper switching transistors are turned off, and the inductor current of each phase is dynamically balanced through inductive coupling.
8. An interleaved modulation control device based on inductive coupling, characterized in that, An analog converter used in a motor simulator, wherein the analog converter is an n-phase interleaved coupled half-bridge converter, where n is an integer greater than 1, and any two phases of the half-bridge circuit are inductively coupled; the device includes: The acquisition module is used to acquire the reference current signal generated by the operation of the converter under test in the motor simulator; The generation module is used to generate n drive signals with staggered phases and independently controllable duty cycles based on the difference between the reference current signal and the total inductor current of the analog converter; wherein, the switching period of each phase drive signal is the same, the phase difference between two adjacent phase drive signals is π / n, and the duty cycle of each phase drive signal is independently adjusted according to the difference. The switching module is used to apply the n driving signals to the switching transistors of the n phase half-bridges corresponding to the n-phase interleaved half-bridge converter, so that the analog converter switches in 2n operating modes; wherein, in any switching cycle: when the period corresponding to the rising phase of the reference current signal is reached, the lower switching transistors of the n phase half-bridges are controlled to turn on independently in sequence according to the interleaved phase, the conduction duration of each phase lower switching transistor is independently controllable, and at the same time only the lower switching transistor of one phase is turned on, while the lower switching transistors of the other phases are turned off and the upper switching transistors are turned on; The balancing module is used to dynamically balance the inductor currents of the n phase half-bridges during the process of the total inductor current tracking the reference current signal through the inductive coupling between any two phase half-bridge circuits.
9. A computer storage medium, characterized in that, The computer storage medium stores a plurality of instructions adapted for loading by a processor and executing the steps of the method as described in any one of claims 1 to 7.
10. An electronic device, characterized in that, It includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steps of the method as described in any one of claims 1 to 7.