Methods, systems, devices, and media for integrating a plc with a pfm / psm-based llc resonant converter

Abstract

The application provides a method, system, device and medium for integrating PFM / PSM-based LLC resonant converter with PLC, according to the full-bridge rectification topology structure of the full-bridge LLC resonant converter, the equivalent circuit FHA model of the LLC resonant converter is obtained by using the fundamental harmonic analysis method, and the PFM modulation strategy is used to realize wide-range output voltage regulation of the LLC resonant converter; according to the small signal model of the LLC resonant converter, the PSM is used to introduce zero voltage regulation output voltage disturbance to the input voltage, the linear relationship between the input voltage disturbance and the output voltage disturbance is used, and the LLC resonant converter integrated with PLC is completed; the PFM is used for power modulation, and the PSM is used for information modulation, so that the wide-range output voltage of the LLC resonant converter is ensured; the PLC demand under different working conditions is met, and the power quality and the soft switching performance are not affected; the communication controller or the coupling element is replaced by a simple operational amplifier and its peripheral circuit, so that the system volume is reduced, and the system cost is reduced.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of power electronic power conversion and power line communication, and particularly relates to a method, system, device and medium for integrating PLC based on PFM / PSM LLC resonant converter. BACKGROUND

[0002] Under the dual pressure of energy demand and environmental protection, distributed generation technology has gained more and more attention and application. However, a large number of distributed power sources, such as solar cells, fuel cells, wind turbines and small gas turbine combined heat and power, will have a significant impact on grid peak shaving and safe operation of the system if they are directly connected to the grid. Adopting microgrid form to connect to the main grid is a more effective way. Compared with AC microgrid, DC microgrid does not need to track the phase and frequency of the voltage, and the controllability and reliability are greatly improved, so it is more suitable for the access of DER and load. Similar to AC microgrid, the operation of DC microgrid also needs to collect information of DER units with different characteristics through communication between controllers at the distribution network level, microgrid level and unit level. The characteristics of DER units with power electronic devices as interface circuits are quite different from those of conventional synchronous machines, so the reliability and speed of communication technology are required to be more stringent in the process of operation control and energy management of microgrid.

[0003] PLC does not require line investment compared with field bus, and is an economical choice for DC microgrid with stable structure such as photovoltaic network and energy storage network. For traditional PLC, additional inductance or capacitance coupling unit is used to embed data signal into power line, which increases the system cost and volume. In the prior art, the modulation method of Buck converter, Boost converter or phase-shift full-bridge converter is fixed-frequency PWM, but the ripple amplitude is small and uncontrollable, which limits the communication distance of PLC; it is difficult to improve the communication rate by using a control loop to adjust the output disturbance to require a high cut-off frequency to make the output voltage disturbance have a large enough amplitude and a high enough frequency; LLC resonant converter generally uses PFM to regulate the output voltage due to the resonant tank, and the output power and output disturbance can be regulated simultaneously by using PSM and PFM hybrid modulation. SUMMARY

[0004] In view of the problems in the prior art, the present application provides a method, system, device and medium for integrating PLC based on PFM / PSM LLC resonant converter, which maintains a wide range of output voltage, has controllable communication signal strength, simplified hardware and other advantages, can improve the economy of DC microgrid, and ensures the safety of communication.

[0005] The present application is implemented by the following technical solutions:

[0006] The method for integrating PFM / PSM-based LLC resonant converter with PLC comprises the following steps:

[0007] According to the full-bridge LLC resonant converter full-bridge rectifier topology structure, the equivalent circuit FHA model of the LLC resonant converter is obtained by using the fundamental harmonic analysis method, and the PFM modulation strategy is used to realize wide-range output voltage regulation of the LLC resonant converter.

[0008] According to the small signal model of the LLC resonant converter, the PSM is used to introduce zero voltage regulation output voltage disturbance in the input voltage, and the linear relationship between the input voltage disturbance and the output voltage disturbance is used to complete the integration of the LLC resonant converter with PLC.

[0009] Further, the wide-range output voltage is:

[0010]

[0011] Wherein, V ab is the fundamental wave of the resonant tank input voltage, V o_ac is the fundamental wave of the resonant tank output voltage, Z ac is the equivalent impedance on the secondary side, Lm is the excitation inductance, Lr is the resonant inductance, Cr is the resonant capacitance, and Zac is the equivalent alternating current load.

[0012] Further, the voltage gain M PFM of the equivalent circuit FHA model is defined as nV o / V in , and the voltage gain M PFM is:

[0013]

[0014] Wherein, K is the inductance ratio, Q is the quality factor, f n is the ratio of switching frequency to resonant frequency.

[0015] Further, the input voltage waveform of the PSM regulation disturbance has the Fourier decomposition and Fourier coefficient as:

[0016]

[0017] a0=0

[0018] a n =0

[0019]

[0020] Wherein, a0 is the direct current component, a n , b nis the amplitude of the harmonic component, ω is the angular frequency corresponding to the switching frequency, and d is the duty cycle of the positive half-wave in one switching period T.

[0021] Further, the duty cycle d is:

[0022]

[0023] wherein, is the phase shift angle, and the phase shift angle The disturbance of the phase shift angle can generate an input voltage disturbance of the corresponding frequency, thereby generating an output voltage disturbance, so that the output voltage carries information.

[0024] Further, the phase shift angle The disturbance frequencies of the phase shift angle are f0 and f1, respectively, the signal "0" is sent using the frequency f0, and the data "1" is sent using the frequency f1, to constitute BFSK information modulation.

[0025] If the switching frequency is f s , the control loop cutoff frequency is f c , and f c < f0, f1 << f s , the disturbance signal is affected by the switching ripple and the output voltage power quality is ensured.

[0026] Further, the disturbance frequencies f0 and f1 are sampled using DFT, and if the equal-interval sampling rate is f sam , the frequency domain resolution f DFT of the DFT is N is the number of sampling points in a DFT period;

[0027] If f0 = k0f DFT , f1 = k1f DFT , k0 and k1 are unequal positive integers, and |k1-k0|=1, the information data is accurately demodulated.

[0028] A system of an LLC resonant converter integrated with PLC based on PFM / PSM hybrid modulation, comprising

[0029] The PFM modulation module is configured to obtain an equivalent circuit FHA model of the LLC resonant converter by using a fundamental harmonic analysis method according to a full-bridge LLC resonant converter full-bridge rectifier topology structure, and to realize wide-range output voltage regulation of the LLC resonant converter by using a PFM modulation strategy.

[0030] The PSM regulation module is configured to introduce zero voltage regulation output voltage disturbance into an input voltage by using PSM according to a small signal model of the LLC resonant converter, and to complete the LLC resonant converter integrated with PLC by using a linear relationship between the input voltage disturbance and the output voltage disturbance.

[0031] A computer device comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the steps of the method for integrating PLC of PFM / PSM-based LLC resonant converter when executing the computer program.

[0032] A computer readable storage medium stores a computer program, and the computer program implements the steps of the method for integrating PLC of PFM / PSM-based LLC resonant converter when executed by a processor.

[0033] Compared with the prior art, the present application has the following beneficial technical effects:

[0034] The present application provides a method, system, device and medium for integrating PLC of PFM / PSM-based LLC resonant converter, according to the full-bridge LLC resonant converter full-bridge rectifier topology structure, the fundamental harmonic analysis method is used to obtain the equivalent circuit FHA model of the LLC resonant converter, and the PFM modulation strategy is used to realize wide range output voltage regulation of the LLC resonant converter; according to the small signal model of the LLC resonant converter, the PSM is used to introduce zero voltage regulation output voltage disturbance at the input voltage, and the linear relationship between the input voltage disturbance and the output voltage disturbance is used to complete the LLC resonant converter integrated PLC; the present application uses PFM / PSM hybrid modulation to realize power conversion and signal modulation at the same time, PFM is used for power modulation, and PSM is used for information modulation, under the decoupling modulation of communication and power, the wide range output voltage of the LLC resonant converter is ensured; the PLC demand under different working conditions is met, and the power quality and soft switching performance are not affected; the simple operational amplifier and its peripheral circuit replace the communication controller or coupling element, the system volume is reduced, and the wired communication line is saved, the PLC rate of the LLC resonant converter of the present application can reach 1kb / s in the range of 1.5kW output power; the system cost is reduced, and the present application has wide application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 The present application is a method flow chart for integrating PLC of PFM / PSM-based LLC resonant converter;

[0036] Figure 2 The present application is a full-bridge LLC resonant converter topology structure in the specific embodiment;

[0037] Figure 3 The present application is an equivalent circuit FHA model of the LLC resonant converter in the specific embodiment;

[0038] Figure 4 The present application is a voltage gain curve of the LLC resonant converter in the specific embodiment;

[0039] Figure 5 LLC resonant converter power control block diagram in embodiments of the present application;

[0040] Figure 6 LLC resonant converter integrated PLC network structure in embodiments of the present application;

[0041] Figure 7 Input voltage fundamental amplitude modulation method in embodiments of the present application, wherein (a) is to modify input voltage amplitude, (b) is to introduce zero voltage, and (c) is to introduce non-zero voltage;

[0042] Figure 8 PSM waveform in embodiments of the present application;

[0043] Figure 9 Input voltage waveform of PSM in embodiments of the present application;

[0044] Figure 10 Basic principle diagram of power / data hybrid modulation in embodiments of the present application;

[0045] Figure 11 Equivalent circuit model of full-bridge LLC resonant converter in embodiments of the present application;

[0046] Figure 12 Hardware filter structure schematic diagram in embodiments of the present application;

[0047] Figure 13 Experimental waveform diagram of output voltage 18V and PLC transmitted data "101010" in embodiments of the present application;

[0048] Figure 14 Soft switching waveform when output voltage is 18V and PLC is integrated in embodiments of the present application, wherein (a) is the driving signal and drain-source voltage of switch S1, (b) is the driving signal and drain-source voltage of switch S2, (c) is the driving signal and drain-source voltage of switch S3, and (d) is the driving signal and drain-source voltage of switch S4;

[0049] Figure 15 Experimental waveform diagram of output voltage 24V and PLC transmitted data "110110" in embodiments of the present application;

[0050] Figure 16Fig. (a) is the driving signal and drain-source voltage of switch tube S1, Fig. (b) is the driving signal and drain-source voltage of switch tube S2, Fig. (c) is the driving signal and drain-source voltage of switch tube S3, and Fig. (d) is the driving signal and drain-source voltage of switch tube S4.

[0051] Figure 17 Fig. is an experimental waveform diagram of the output voltage 30V and the PLC sending data "001001" in the embodiment of the present application;

[0052] Figure 18 Fig. is a PLC soft switching waveform when the output voltage is 30V and the PLC is integrated in the embodiment of the present application, wherein Fig. (a) is the driving signal and drain-source voltage of switch tube S1, Fig. (b) is the driving signal and drain-source voltage of switch tube S2, Fig. (c) is the driving signal and drain-source voltage of switch tube S3, and Fig. (d) is the driving signal and drain-source voltage of switch tube S4. DETAILED DESCRIPTION

[0053] The present application will be further described below in connection with specific embodiments, which are intended to explain the present application but not to limit it.

[0054] In order to make the personnel in the technical field better understand the present application scheme, the technical scheme in the embodiments of the present application will be clearly and completely described below in connection with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by the personnel in the field without creative labor should belong to the protection scope of the present application.

[0055] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not necessarily limit to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0056] The present application provides a method for integrating a PLC based on a PFM / PSM LLC resonant converter, comprising the following steps:

[0057] According to the full-bridge LLC resonant converter full-bridge rectifier topology, the equivalent circuit FHA model of the LLC resonant converter is obtained by using the fundamental harmonic analysis method, and the PFM modulation strategy is used to realize wide range output voltage regulation of the LLC resonant converter.

[0058] According to the small signal model of the LLC resonant converter, the PSM is used to introduce zero voltage regulation output voltage disturbance at the input voltage, and the linear relationship between the input voltage disturbance and the output voltage disturbance is used to complete the integration of the PLC of the LLC resonant converter.

[0059] Further, as shown in Figure 2 and Figure 3 , without considering the secondary side leakage inductance, according to the voltage division law, the wide range of output voltage is:

[0060]

[0061] Where, V ab is the fundamental wave of the resonant tank input voltage, V o_ac is the fundamental wave of the resonant tank output voltage, and Z ac is the equivalent impedance on the secondary side.

[0062] Further, according to the equivalent circuit FHA model of the LLC resonant converter and the wide range of output voltage, the output voltage can be regulated by modulating the resonant tank input voltage, resonant tank elements and secondary equivalent impedance. In order to meet the universality of the integration of the PLC of the LLC resonant converter, the present application adopts PFM control output power. When the LLC resonant converter adopts PFM, the duty cycles of S1, S2, S3 and S4 are constant at 0.5, and by adjusting the switching frequency, the impedance of the resonant tank element is modified, the voltage distribution between the resonant tank and the load is changed, and wide range output voltage regulation is realized. The voltage gain M PFM of the equivalent circuit FHA model is defined as nV o / V in , and the voltage gain M PFM is:

[0063]

[0064] Where, K is the inductance ratio, Q is the quality factor, and f n is the ratio of switching frequency to resonant frequency.

[0065] Specifically, the voltage gain M PFM is determined by the inductance ratio K=L m / L r , the quality factor and the ratio of switching frequency to resonant frequency f n =f s / f r .Figure 4 The voltage gain curves of different quality factor values Q are shown when the inductance ratio K = 5; the Q value is related to the load size and is selected to meet the required gain range; after the Q value is determined, the voltage gain changes with the switching frequency to achieve PFM regulation of the output voltage steady-state quantity; the control diagram of the LLC resonant converter using PFM is as shown in Figure 5 The voltage control oscillator (VCO) adjusts the switching frequency according to the control signal generated by the regulator.

[0066] The controller transmits and receives data signals through the power line, without the need for additional communication equipment, and the network structure of power and data transmission is as shown in Figure 6 On the DC microgrid, power transmission mainly relies on the DC component, and information transmission can rely on the harmonic component. The main idea is to create a small disturbance in the voltage on the power line to generate a corresponding harmonic component to achieve information transmission. The basic LLC resonant converter modulation method can adjust the input voltage, resonant tank impedance, or secondary side impedance to create a small disturbance in the output voltage. Adjusting the resonant tank impedance and the secondary side impedance requires special components or changes to the topology. In order to ensure the universality and simplicity of integrated PLC, the application uses the method of adjusting the input voltage to create a disturbance.

[0067] As shown in Figure 7 The disturbance of the input voltage can be an amplitude disturbance, a zero voltage disturbance, or a non-zero voltage disturbance. By introducing a zero voltage to adjust the output voltage disturbance, the linear relationship between the input voltage disturbance and the output voltage disturbance is ensured, and the topology does not need to be modified, which can meet the universality and simplicity. Adjusting the duty cycle or phase shift angle can be equivalent to introducing a zero voltage, and the application uses PSM to adjust the disturbance, and the drive waveform and output waveform are as shown in Figure 8 The phase shift angle The disturbance causes a zero voltage disturbance, which in turn causes a disturbance in the input voltage fundamental amplitude.

[0068] Further, as shown in Figure 9 The input voltage waveform using PSM is as shown in

[0069]

[0070] a0= 0

[0071] a n = 0

[0072]

[0073] where a0is the DC component, a n , b nis the amplitude of the harmonic component, ω is the angular frequency corresponding to the switching frequency, d is the duty cycle of the positive half-wave in one switching period T.

[0074] Further, the duty cycle d is:

[0075]

[0076] wherein, is the phase shift angle, the phase shift angle The disturbance of the phase shift angle can generate an input voltage disturbance of the corresponding frequency, thereby generating an output voltage disturbance, so that the output voltage carries information.

[0077] The above shows that the disturbance of the phase shift angle can generate an input voltage disturbance of the corresponding frequency, thereby generating an output voltage disturbance, so that the output voltage carries information. The PFM / PSM hybrid modulation can be used to realize power conversion and signal modulation at the same time, PFM is used for power modulation, and PSM is used for information modulation. The basic principle of hybrid modulation is as shown in Figure 10 .

[0078] Avoiding the influence of the disturbance signal on the switching ripple and ensuring the power quality of the output voltage, because the sampling frequency is limited, the harmonic frequency that can be calculated by DFT is limited, further, the phase shift angle The disturbance frequency of the phase shift angle is f0 and f1 respectively, the signal "0" is sent using the frequency f0 disturbance, and the data "1" is sent using the frequency f1 disturbance, to constitute BFSK information modulation;

[0079] If the switching frequency is f s , the control loop cutoff frequency is f c , then f c <f0, f1 << f s , avoiding the influence of the disturbance signal on the switching ripple and ensuring the power quality of the output voltage.

[0080] Further, the disturbance frequencies f0 and f1 are sampled by DFT, if the equal interval sampling rate is f sam , then the frequency domain resolution f DFT of DFT is N is the number of sampling points in one DFT period;

[0081] If f0=k0f DFT , f1=k1f DFT , k0, k1 are unequal positive integers, and |k1-k0|=1, then the information data is accurately demodulated.

[0082] 100 kHz is selected as the resonance frequency f r and the sampling frequency f samThe sampling sequence is updated every sampling period, and the number of sampling points N = 32, so the frequency resolution f DFT = 3.125 kHz of DFT can be calculated, and the phase shift angle disturbance frequency f0, f1relative to the DFT frequency resolution f DFT The multiples are k0= 3 and k1= 4, respectively.

[0083] The extended describing function method can accurately reflect the small-signal transmission characteristics of the system and obtain the transmission process of the disturbance signal, as shown in Figure 11 The equivalent circuit model of the full-bridge LLC resonant converter is shown in FIG. 1, and according to the equivalent circuit model, the nonlinear state equation of the circuit can be obtained by using Kirchhoff's law as follows:

[0084]

[0085]

[0086]

[0087]

[0088] The output voltage equation is:

[0089]

[0090] where v cr is the resonant capacitor voltage, and v co is the output capacitor voltage. In the formula, v ab , sgn(i r -i m ), and |i r -i m | are all nonlinear variables, which are linearized by using the extended describing function; the LLC resonant converter operates near the resonant frequency, and the waveforms of the related state variables can be approximately represented by the fundamental wave. The resonant current i r , the excitation current i m , and the resonant voltage v cr can be approximately represented by the following fundamental wave components:

[0091] i r ≈i rs sin(ωt)+i rc cos(ωt),

[0092] i m ≈i ms sin(ωt)+i mc cos(ωt),

[0093] v cr ≈v crssin(ωt) + v crc cos(ωt),

[0094] The above nonlinear state variables are expressed into fundamental wave form by using the extended describing function method:

[0095] v ab ≈f1(v ab )sin(ωt),

[0096] sgn(i r -i m )≈f2(i rs -i ms ,i rc -i mc )sin(ωt) + f3(i rs -i ms ,i rc -i mc )cos(ωt),

[0097] |i r -i m |≈f4(i rs -i ms ,i rc -i mc ),

[0098] When the circuit duty ratio d is 0.5, according to Fourier transform, the following equation can be obtained:

[0099]

[0100]

[0101]

[0102]

[0103] where v g is the amplitude of square wave v ab , A p is the amplitude of current i p , and then

[0104] The extended describing function equation is substituted into the nonlinear state equation, and the harmonic balance theory is used, and the sine component and the cosine component of each state variable are balanced respectively, so that the harmonic balance equation can be obtained, and the state space equation of the LLC resonant converter large signal is solved as:

[0105]

[0106] A small signal disturbance is applied to the steady state working point, Ignoring the terms of second-order infinitesimals, we can obtain the small-signal model of the LLC resonant converter, represented as shown in the state-space equation. In the formula Select input voltage disturbance As an input variable, the disturbance of the output voltage As the output variable, it can be easily derived from the above state-space expression. transfer function

[0107] according to Figure 9 By using Fourier transform, the relationship between the fundamental amplitude of the input voltage and the duty cycle can be obtained as follows: Without considering dead zone, the duty cycle D = 0.5 in steady state, and the maximum duty cycle value does not exceed 0.5. PSM causes duty cycle disturbance. for Among them, a d Let ω be the amplitude of the disturbance. d Let be the frequency of the disturbance angular frequency; available right Perform a Taylor expansion. Because the duty cycle perturbation is small, taking the first two terms yields a satisfactory approximation; therefore, it can be derived that...

[0108] Where V g For steady-state quantities, The disturbance caused by the duty cycle can be obtained.

[0109]

[0110]

[0111] As can be seen from the right side of the equation, the first term is the steady-state DC quantity, and the second term is the angular frequency ω. d The input voltage disturbance, the third term is the angular frequency 2ω d Input voltage disturbance; angular frequency 2ω d The disturbance amplitude is the angular frequency ω d The disturbance amplitude is 1 / 4 of the original value, and the gain decreases as the frequency increases, which is not conducive to generating output voltage disturbance; therefore, let Equivalent to DC side voltage v g The disturbance will generate an angular frequency ω at the output. d Output voltage disturbance This disturbance can be used to achieve PLC integration; both the DC and AC components of the disturbance are very small, meeting power quality requirements. Implementing a PLC requires amplifying the AC component using a filter.

[0112] Power filtering is similar to demodulation in communication process. In DC / DC converter, power filtering gets DC component and provides stable output voltage. While signal demodulation needs to filter k-th harmonic from output voltage ripple to get data information. Therefore, signal filtering circuit is designed to realize power and information demodulation. k-th harmonic is sent to DSP, and harmonic frequency is calculated by DFT to realize analog information to digital data conversion.

[0113] In this application, k-th harmonic is extracted from output voltage by hardware filter. Hardware filter is composed of voltage divider, three operational amplifier instrumentation amplifier, filter circuit and bias circuit, as shown in Fig. 2. Output voltage is divided to meet operational amplifier input voltage range. High input impedance high-pass filter circuit is placed in front stage to isolate output voltage DC component. Middle stage is composed of three operational amplifier instrumentation amplifier to suppress common-mode voltage and amplify signal. Voltage-controlled band-pass filter is used again to further attenuate DC component and high frequency noise. Finally, bias circuit provides bias voltage to make signal sent to DSP ADC sampling module smoothly. According to disturbance frequency, signal band-pass filter bandwidth is set to 7kHz-15kHz. Filter amplifies harmonic signal, so that maximum harmonic signal amplitude is about 1.5V. Adding 1.5V bias voltage, output signal voltage range is 0V-3V, which meets DSP sampling voltage range. Signal amplitude is calculated in DSP interrupt function. Figure 12

[0114] In order to detect harmonic frequency of filter output, sliding window DFT algorithm is realized in DSP. DFT is:

[0115]

[0116]

[0117] x(n) is the nth element of uniformly sampled sequence {x(n)} with sampling point number N; X F (k) represents DFT of k-th harmonic of sequence {x(n)}, harmonic amplitude calculation is X F (k) divided by spectrum bandwidth. In this application, two different frequency harmonics are introduced to represent data information, so only two times of above formula are needed to get two harmonic amplitudes; in order to improve communication rate as much as possible, sliding window DFT is used to improve operation rate:

[0118]

[0119]

[0120] wherein, X *F (k) is DFT of k-th harmonic of sequence {x * ​(n)}kth harmonic; the sequence {x(n)} is {x(0), x(1), x(N-1)}; the sequence {x(n)} is {x(1), x(2), x(N)}. * (n)}kth harmonic; the sequence {x(n)} is {x(0), x(1), x(N-1)}; the sequence {x

[0121] As can be seen from the sliding window DFT, the DFT result of the first sequence can be used when calculating the two continuous sequences, avoiding the recalculation of the entire sequence, greatly reducing the operation amount and the calculation time, making it possible to perform the sliding window DFT in the interrupt function, and at the same time, the number of sampling points can be expanded to improve the DFT precision.

[0122] Figure 13 The waveform is the 18V output voltage, the PLC sends the data "010101", the phase shift angle perturbation frequency is switched between 9.375kHz and 12.5kHz, when sending bit "0", the phase shift angle perturbation frequency is 9.375kHz; when sending bit "1", the phase shift angle perturbation frequency is 12.5kHz; channel CH1 shows the LLC resonant converter output voltage waveform, and the switching ripple is still dominant, because the phase shift angle perturbation amplitude is small, the output voltage perturbation amplitude caused by it is much smaller than the switching ripple in the output voltage, so the output voltage ripple caused by the PLC does not cause power quality problems, the passband gain of the hardware filter is about 500, which successfully amplifies the harmonic amplitude carrying information and increases the filter link attenuation switching ripple; channel CH2 shows the perturbation signal waveform amplified by the filter, and the change of the perturbation signal can be clearly seen, the amplitude of the perturbation signal obtained by sampling and DFT calculation is compared with the threshold value V th The comparison finally obtains the demodulated data; channel CH3 shows the demodulated signal data, and the DFT operation in the DSP and the output of the data information cause the delay between the ripple and the data. Figure 14 The four figures are the drive signals and drain-source voltage waveforms of the four primary side switch tubes of the LLC resonant converter when the output voltage is 18V and the PLC is performed, when the drive voltage Vgs rises, the drain-source voltage Vds has dropped to 0, realizing ZVS, which shows that the PWM / PSM hybrid modulation does not affect the soft switching performance of the LLC resonant converter, ensuring the efficiency advantage of the LLC resonant converter.

[0123] Figure 15 The waveform is the 24V output voltage, the PLC sends the data "110110"; Figure 16 The drive signals and drain-source voltage waveforms of the four primary side switch tubes of the LLC resonant converter when the output voltage is 24V and the PLC is performed, when the drive voltage Vgs rises, the drain-source voltage Vds has dropped to 0, realizing ZVS; Figure 17 The waveform is the 30V output voltage, the PLC sends the data "100100"; Figure 18To output a 30V voltage and generate drive signals and drain-source voltage waveforms for the four primary-side switches of the LLC during PLC operation, similarly, when the drive voltage Vgs rises, the drain-source voltage Vds drops to 0, achieving ZVS. As the output voltage increases, the static operating point changes, and the output disturbance increases while the input disturbance amplitude remains constant. Therefore, it is necessary to adjust the disturbance amplitude by analyzing the model and combining it with the filter passband gain, or to use closed-loop control to ensure that the disturbance meets the operating range of the load.

[0124] Communication baud rate R B can be Calculation yielded T b The signal symbol width is given. Based on the perturbation frequency, the communication baud rate R is set to achieve a reliable communication rate. B A perturbation frequency of 1 / 10 is used to achieve 1 kb / s, ensuring sufficient perturbation cycles within the signal symbol width for accurate signal detection. As the perturbation frequency increases, the signal gain gradually decreases, exhibiting low-pass filtering characteristics. Because the perturbation frequency is positively correlated with the communication rate, the decrease in high-frequency gain limits the communication rate. To achieve the desired communication baud rate R... B Increasing the switching frequency can improve the disturbance frequency.

[0125] In one embodiment of the present invention, a system for integrating a PLC with an LLC resonant converter based on PFM / PSM hybrid modulation is provided, which can be used to implement the above-mentioned method for integrating a PLC with an LLC resonant converter based on PFM / PSM. Specifically, the system for integrating a PLC with an LLC resonant converter based on PFM / PSM hybrid modulation includes...

[0126] The PFM modulation module is used to obtain the equivalent circuit FHA model of the LLC resonant converter based on the full-bridge rectifier topology of the full-bridge LLC resonant converter by using the fundamental harmonic analysis method, and to achieve wide-range output voltage regulation of the LLC resonant converter by using the PFM modulation strategy.

[0127] The PSM regulation module is used to regulate the output voltage disturbance by introducing zero voltage into the input voltage according to the small-signal model of the LLC resonant converter. By utilizing the linear relationship between the input voltage disturbance and the output voltage disturbance, the LLC resonant converter can be integrated into a PLC.

[0128] In another embodiment of the present application, a computer device is provided, which comprises a processor and a memory for storing a computer program, the computer program comprising program instructions, and the processor is configured to execute the program instructions stored in the computer storage medium. The processor can be a central processing unit (CPU), and can also be other general-purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc., which are the computing core and control core of the terminal, and are suitable for implementing one or more instructions, and are particularly suitable for loading and executing one or more instructions in the computer storage medium to implement a corresponding method flow or a corresponding function; the processor in the embodiments of the present application can be operated by the method of integrating PLC in the PFM / PSM-based LLC resonant converter.

[0129] In another embodiment of the present application, the present application further provides a storage medium, specifically a computer readable storage medium (Memory), which is a memory device in the computer device, and is used for storing programs and data. It can be understood that the computer readable storage medium herein can include the built-in storage medium in the computer device, and of course can also include the expansion storage medium supported by the computer device. The computer readable storage medium provides a storage space, and the storage space stores the operating system of the terminal. Moreover, one or more instructions suitable for being loaded and executed by the processor are also stored in the storage space, and the instructions can be one or more computer programs (including program codes). It should be noted that the computer readable storage medium herein can be a high-speed RAM memory, or a non-volatile memory such as at least one disk memory. One or more instructions stored in the computer readable storage medium can be loaded and executed by the processor to implement the corresponding steps of the method of integrating PLC in the PFM / PSM-based LLC resonant converter.

[0130] Those skilled in the art will appreciate that embodiments of the application can be devised for a method, a system, or a computer program product. Accordingly, the present application can be embodied in the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present application can take the form of a computer program product on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROMs, optical storage devices, etc.) embodying computer readable program code.

[0131] The present application is described in reference to the flowchart and / or block diagrams of the method, apparatus (system) and computer program product according to embodiments of the application. It will be understood that each block of the flowchart and / or block diagrams, and combinations of blocks in the flowchart and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart and / or block diagram block or blocks. Figure 1 one or more functions specified in the flowchart and / or block diagram block or blocks. Figure 1 one or more functions specified in the flowchart and / or block diagram block or blocks.

[0132] These computer program instructions can also be stored in a computer- readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instructions which implement the function specified in the flowchart and / or block diagram block or blocks. Figure 1 one or more functions specified in the flowchart and / or block diagram block or blocks. Figure 1 one or more functions specified in the flowchart and / or block diagram block or blocks.

[0133] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart and / or block diagram block or blocks. Figure 1 one or more functions specified in the flowchart and / or block diagram block or blocks. Figure 1 one or more functions specified in the flowchart and / or block diagram block or blocks.

[0134] Finally, it should be noted that the above-described embodiments are merely intended for describing and illustrating, not limiting, the technical solutions of the present application; even though the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements to some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method of integrating a PLC for a PFM / PSM based LLC resonant converter, characterized by, The method comprises the following steps: According to the full-bridge LLC resonant converter full-bridge rectifier topology, the equivalent circuit FHA model of the LLC resonant converter is obtained by using the fundamental harmonic analysis method, and the PFM modulation strategy is used to realize wide range output voltage regulation of the LLC resonant converter; According to the small signal model of the LLC resonant converter, the PSM is used to introduce zero voltage regulation output voltage disturbance in the input voltage, and the linear relationship between the input voltage disturbance and the output voltage disturbance is used to complete the PLC integration of the LLC resonant converter; the Fourier decomposition and Fourier coefficient of the input voltage waveform of the PSM regulation disturbance are: ； wherein a0 is a direct current component, a n , b n is a harmonic component amplitude, is an angular frequency corresponding to the switching frequency, is a duty cycle of the positive half-wave within one switching period T; The duty cycle Is: ； wherein, is a phase shift angle, the phase shift angle The disturbance of the phase shift angle can generate an input voltage disturbance of a corresponding frequency, thereby generating an output voltage disturbance, so that the output voltage carries information; The phase shift angle The disturbance frequency of and , using frequency The disturbance sends signal "0", using frequency The disturbance sends data "1", constituting BFSK information modulation; If the switching frequency is , the control loop cutoff frequency is , then , avoid the disturbance signal affected by the switching ripple and ensure the output voltage power quality; Disturbance frequency and Using DFT for sampling, if the sampling rate is equal at intervals... Then the frequency domain resolution of the DFT for N is the number of sampling points in one DFT period; If , , , , are unequal positive integers, and , then the information data is accurately demodulated.

2. The method of claim 1, wherein the PFM / PSM based LLC resonant converter integrated PLC is characterized by, The wide range of output voltages are: ； wherein, is the fundamental of the input voltage of the resonant tank, is the fundamental of the output voltage of the resonant tank, is the equivalent impedance on the secondary side, Lm is the magnetizing inductance, Lr is the resonant inductance, Cr is the resonant capacitance, and Zac is the equivalent ac load.

3. The method of claim 1, wherein the PFM / PSM based LLC resonant converter integrated PLC is characterized by, The voltage gain of the equivalent circuit FHA model defined as , the voltage gain is: ； where K is the inductance ratio, Q is the quality factor, and f n is the ratio of the switching frequency to the resonant frequency.

4. A system of LLC resonant converter integrated PLC based on PFM / PSM hybrid modulation, characterized in that, The method for integrating PLC based on the PFM / PSM LLC resonant converter according to any one of claims 1-3 comprises The PFM modulation module is used to obtain the equivalent circuit FHA model of the LLC resonant converter according to the full-bridge LLC resonant converter full-bridge rectifier topology, and the PFM modulation strategy is used to realize wide range output voltage regulation of the LLC resonant converter; The PSM regulation module is used to complete the PLC integration of the LLC resonant converter according to the small signal model of the LLC resonant converter, and the PSM is used to introduce zero voltage regulation output voltage disturbance in the input voltage, and the linear relationship between the input voltage disturbance and the output voltage disturbance is used to complete the PLC integration of the LLC resonant converter.

5. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, The processor executes the computer program to realize the steps of the method for integrating PLC based on the PFM / PSM LLC resonant converter according to any one of claims 1-3.

6. A computer-readable storage medium storing a computer program, the computer program comprising instructions that, when executed by a computer, cause the computer to perform the method of any one of claims 1 to 5. The computer program is executed by the processor to realize the steps of the method for integrating PLC based on the PFM / PSM LLC resonant converter according to any one of claims 1-3.

Images