Node signal-enhanced digital power communication power supply and communication method thereof

Abstract

The application discloses a digital power communication power supply with enhanced node signal and a communication method thereof, which provides high-quality power supply voltage when signals are sent, adjusts input admittance to be optimal when signals are received, and realizes signal enhancement of receiving nodes in multi-node communication. The auxiliary power supply comprises a digital power communication module and an admittance correction module. The input side of the digital power communication module is connected with a DC bus, and the output side is connected with a converter control system. The input side of the admittance correction module is connected with a third winding of a transformer of the digital power module, and the output side is connected in parallel with the output of the digital power communication module, and is used for adjusting input / output admittance of the auxiliary power supply in different working modes. The application realizes information interaction among different converters in a DC micro-grid, guarantees high-quality power supply quality by adjusting output admittance when information is sent, and improves signal strength received by the auxiliary power supply by adjusting input admittance of the auxiliary power supply when multi-node communication is performed.

Description

Technical Field

[0001] This invention relates to the fields of power electronics and communication technology, and in particular to a digital power communication power supply with node signal enhancement and its communication method. Background Technology

[0002] With the rapid development of distributed new energy sources, especially the large-scale integration of photovoltaic and electric vehicles, the structure and load characteristics of traditional distribution networks have been changed. This has resulted in distribution networks exhibiting characteristics such as greater source / load volatility, poorer system robustness, and short-term large peak loads. This places higher demands on the lean management and economic operation of the power grid system, and information interaction among distributed energy sources is the key to achieving this goal.

[0003] However, traditional communication technologies, due to their shortcomings in communication cost, security, and flexibility in widespread deployment, struggle to meet the communication demands of power grid structures where distributed energy resources are increasingly prevalent. Power line carrier communication, using power lines as the communication channel, eliminates the need for additional communication lines, effectively reducing information exchange costs and offering another solution for information collection in new power grids. However, power line carrier communication requires additional carrier modules and power supplies, and currently, in multi-node, long-distance communication environments, increasing carrier signal strength to ensure communication quality somewhat limits its application scenarios. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a digital power communication power supply and communication method for enhancing node signals, in order to address the shortcomings of the prior art and solve the problem of difficulty in ensuring communication signal strength in multi-node, long-distance communication environments.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a digital power communication power supply for enhancing node signals, comprising:

[0006] A digital power communication module includes a resonant inductor, a resonant capacitor, and a high-frequency transformer; one end of the resonant inductor is connected to the positive terminal of a DC power supply, and the other end is connected to the positive terminal of the resonant capacitor and one end of the first winding of the high-frequency transformer; the other end of the first winding is connected to the drain of a first switching transistor; the negative terminal of the resonant capacitor and the source of the first switching transistor are connected to the negative terminal of the DC power supply.

[0007] The admittance correction module includes an inductor. One end of the inductor is connected between one end of the second winding of the high-frequency transformer and the positive terminal of the output capacitor. The other end of the inductor is connected to the drain of the second switching transistor and the drain of the third switching transistor. The source of the second switching transistor is connected to one end of the third winding of the high-frequency transformer and the positive terminal of the second capacitor. The other end of the third winding, the source of the third switching transistor, the other end of the second winding, and the negative terminal of the second capacitor are all connected to the negative terminal of the output capacitor. A second diode is connected between the positive terminal of the second capacitor and one end of the third winding.

[0008] The introduction of the admittance correction module suppresses power output ripple, thus ensuring high-quality power supply. The resonant capacitor and inductor added to the digital power communication module provide the circuit conditions for generating high-frequency communication current during data transmission; during data reception, the resonant circuit formed by the resonant capacitor and inductor provides a low-impedance communication loop for the high-frequency communication current, ensuring low-attenuation signal reception. This invention solves the problem of difficulty in guaranteeing communication signal strength in multi-node, long-distance communication environments. The first switch switching control process includes:

[0009] 1) The output voltage v across the sampling output capacitor o The output voltage v o With the output voltage reference value V o_ref The error signal obtained from the comparison is passed through a PI controller to obtain i. r1 ;

[0010] 2) When the digital power communication power supply is operating in signal transmission mode, the high-frequency digital power communication signal is multiplied bit-by-bit by the binary communication data to be transmitted to obtain i. s , change i s with i r1 The summation yields the reference value I for the input current of the digital power communication power supply. Lref When the digital power communication power supply is operating in the normal power supply mode, i r1 Directly used as the reference value I for digital power communication power input current Lref ;

[0011] 3) Sample the input current i of the digital power communication power supply. in , input current i in With input current reference value I Lref The error signal obtained from the comparison is passed through the P controller to obtain the duty cycle signal. The duty cycle signal is compared with the triangular wave to obtain the drive signal of the first switching transistor.

[0012] The on / off control process of the second and third switching transistors includes:

[0013] A) Sample the voltage v across the second capacitor. c2The voltage v across the second capacitor c2 With the reference value V of the second capacitor voltage c2_ref The error information obtained from the comparison is processed by the PI controller to obtain i. r2 ;

[0014] B) The output voltage v across the sampling output capacitor o The output voltage v o The filtered signal obtained after passing through the bandpass filter is multiplied by the admittance offset coefficient H to obtain i rip When the digital power communication power supply operates in both normal power supply mode and signal transmission mode, i r2 with i rip The summation yields the reference value I of the output current of the admittance correction module. L2ref When the digital power communication power supply is operating in signal receiving mode, i r2 Directly used as the output current reference value I of the admittance correction module L2ref ;

[0015] C) Sample the inductor current of the admittance correction module as the output current i of the admittance correction module. L2 The output current i L2 With output current reference value I L2ref The error obtained from the comparison is processed by the P controller to obtain the duty cycle signal. The duty cycle signal is compared with the triangular wave signal to obtain the drive signal of the second switch. The drive signal of the second switch is inverted to obtain the drive signal of the third switch.

[0016] The present invention also provides a communication method for a digital power communication power supply with node signal enhancement, the method comprising:

[0017] I) Sample digital power communication power supply input current i in , input current i in The signal within the communication frequency band is obtained by using a bandpass filter;

[0018] II) Perform envelope detection on the signal within the communication frequency band to obtain a non-negative envelope signal;

[0019] III) Sample and decide the non-negative envelope signal to obtain high and low level signals, and convert the high and low level signals into "0" and "1" digital signals.

[0020] This invention also provides a control method for a digital power communication power supply for node signal enhancement, including a digital power communication module control method and an admittance correction module control method; wherein,

[0021] The digital power communication module control method includes:

[0022] 1) The output voltage v across the sampling output capacitoro The output voltage v o With the output voltage reference value V o_ref The error signal obtained from the comparison is passed through a PI controller to obtain i. r1 ;

[0023] 2) When the digital power communication power supply is operating in signal transmission mode, the high-frequency digital power communication signal is multiplied bit-by-bit by the binary communication data to be transmitted to obtain i. s , change i s with i r1 The summation yields the reference value I for the input current of the digital power communication power supply. Lref When the digital power communication power supply is operating in the normal power supply mode, i r1 Directly used as the reference value I for digital power communication power input current Lref ;

[0024] 3) Sample the input current i of the digital power communication power supply. in , input current i in With input current reference value I Lref The error signal obtained from the comparison is passed through the P controller to obtain the duty cycle signal. The duty cycle signal is compared with the triangular wave to obtain the drive signal of the first switching transistor.

[0025] The admittance correction module control method includes:

[0026] A) Sample the voltage v across the second capacitor. c2 The voltage v across the second capacitor c2 With the reference value V of the second capacitor voltage c2_ref The error information obtained from the comparison is processed by the PI controller to obtain i. r2 ;

[0027] B) The output voltage v across the sampling output capacitor o The output voltage v o The filtered signal obtained after passing through the bandpass filter is multiplied by the admittance offset coefficient H to obtain i rip When the digital power communication power supply operates in both normal power supply mode and signal transmission mode, i r2 with i rip The summation yields the reference value I of the output current of the admittance correction module. L2ref When the digital power communication power supply is operating in signal receiving mode, i r2 Directly used as the output current reference value I of the admittance correction module L2ref ;

[0028] C) Sample the inductor current of the admittance correction module as the output current i of the admittance correction module. L2 The output current i L2With output current reference value I L2ref The error obtained from the comparison is processed by the P controller to obtain the duty cycle signal. The duty cycle signal is compared with the triangular wave signal to obtain the drive signal of the second switch. The drive signal of the second switch is inverted to obtain the drive signal of the third switch.

[0029] Corresponding to the above control method, this invention also provides a control system for a digital power communication power supply with node signal enhancement, including a memory, a processor, and a computer program stored in the memory; the processor executes the computer program to implement the steps of the above control method. To facilitate engineering implementation and application, this invention also provides a method for switching the operating mode of a digital power communication power supply, including:

[0030] Given a first signal and a second signal, input the first signal and the second signal to the control system;

[0031] When both the first and second signals are 0, the control system controls the digital power communication power supply to operate in the normal power supply mode.

[0032] When the first signal is 1 and the second signal is 0, the control system controls the digital power communication power supply to work in signal transmission mode.

[0033] When the first signal is 0 and the second signal is 1, the control system controls the digital power communication power supply to work in signal receiving mode.

[0034] in,

[0035] In normal power supply mode, the digital power communication power supply only provides the power supply voltage;

[0036] In signal transmission mode, the digital power communication power supply injects a high-frequency characteristic current representing the signal into the DC bus, while simultaneously providing the power supply voltage;

[0037] In signal reception mode, the digital power communication power supply increases the input admittance while providing the supply voltage.

[0038] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0039] 1. This invention makes a simple modification to the existing auxiliary power supply structure. By adding an admittance correction branch, it ensures the absorption of power supply output voltage ripple in different modes of the digital power communication power supply, thereby ensuring high-quality power supply of the digital power communication power supply. At the same time, the addition of a resonant capacitor-inductor branch enables the digital power communication power supply to have information transmission and reception functions, thereby having digital power communication capabilities.

[0040] 2. This invention introduces an admittance correction branch on the auxiliary power supply output side, providing a low-impedance absorption circuit for the high-frequency ripple voltage on the output side, thus ensuring the quality of the output voltage.

[0041] 3. In multi-node, long-distance communication, this invention can improve communication reliability by adjusting the input admittance characteristics of the auxiliary power supply of the receiving node, so that as many signals as possible can be received by the receiving node. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of a digital power communication power supply structure for enhancing node signals according to an embodiment of the present invention;

[0043] Figure 2 This is a block diagram of a digital power communication power supply control for node signal enhancement according to an embodiment of the present invention;

[0044] Figure 3 This is a schematic diagram of the equivalent circuit for multi-node communication in a DC microgrid.

[0045] Figure 4 This is a schematic diagram of the current waveforms received by different nodes when three nodes are communicating. Detailed Implementation

[0046] The digital power communication auxiliary power supply of this invention provides power to the distributed new energy interface converter control system while also serving as an information transceiver, enabling information exchange between distributed energy sources. The output side of the digital power communication auxiliary power supply can provide 24V DC power, and the input side is connected to a DC bus, achieving information transmission through the injection of high-frequency current.

[0047] like Figure 1 As shown, the digital power communication power supply for node signal enhancement in this embodiment of the invention includes a digital power communication module and an admittance correction module.

[0048] The digital power communication module includes a resonant inductor L1, a resonant capacitor C1, a first winding N1 and a second winding N2 of a high-frequency transformer, a switching transistor S1, a diode D1, and an output capacitor C. o One end of the resonant inductor L1 is connected to the positive terminal of the DC bus, and the other end is connected to the resonant capacitor C1 and the first winding N1 of the high-frequency transformer. One end of the resonant capacitor C1 is connected to the resonant inductor L1, and the other end is connected to the negative terminal of the DC bus. The first winding N1 of the high-frequency transformer and the switching transistor S1 are connected in series and then in parallel across the resonant capacitor C1 (one end of the first winding is connected to the drain of S1, and the source of S1 is connected to the DC power supply V). dc (Negative terminal), the second winding N2 of the high-frequency transformer passes through diode D1 and output capacitor C. o The positive terminal is connected, and the other end is directly connected to the output capacitor C. oThe negative terminal is connected. The digital power communication module mainly injects high-frequency current into the DC bus and generates a stable 24V power supply by controlling the on / off state of the switching transistor S1.

[0049] The admittance correction module includes diode D2, capacitor C2, switches S2 and S3, inductor L2, and the third winding N3 of the high-frequency transformer. The positive terminal of capacitor C2 is connected in parallel with the third winding N3 of the high-frequency transformer via diode D2. Switches S2 and S3 are connected in series. The drain of switch S2 is connected to the positive terminal of capacitor C2, and the source of switch S3 is connected to the negative terminal of capacitor C2. The connection point of switches S2 and S3 is connected to the output capacitor C3 via inductor L2. o The positive terminal is connected, and the negative terminal of capacitor C2 is connected to the output capacitor C. o The negative terminals are connected, with switches S2 and S3 conducting complementaryly. The admittance correction module corrects the input / output admittance of the digital power communication auxiliary power supply by controlling the complementary conducting switches S2 and S3. To ensure the quality of the 24V power supply, the admittance correction module, connected in parallel to the output capacitor side, provides a low-impedance absorption circuit for ripple current, thereby ensuring a flat voltage across the output capacitor. During information reception, it increases the input admittance of the auxiliary power supply in the signal frequency band, allowing as much signal as possible to flow in and improving communication reliability.

[0050] like Figure 2 As shown in the embodiment of the present invention, the control method of the digital power communication auxiliary power supply includes three parts: digital power modulation, admittance correction control, and digital power demodulation.

[0051] like Figure 2 As shown, digital power modulation controls the on / off state of switch S1 to achieve output voltage control and transmission of characteristic signals for digital power communication. The specific control process is as follows:

[0052] 1) Sample output capacitor voltage v o , will voltage v o With the output voltage reference value V o_ref The error signal obtained from the comparison is passed through a PI controller to obtain i. r1 ;

[0053] 2) When the auxiliary power supply is operating in signal transmission mode, the mode selection switch S m Closed, the high-frequency digital power communication signal and the binary digital modulation signal are multiplied bit by bit to obtain i. s , change i s with i r1 The summation yields the input current reference value I of the digital power communication module. Lref When the auxiliary power supply is operating in the normal power supply mode, the mode selection switch S... m Disconnect, i r1Directly used as the input current reference value I of the digital power communication module Lref ;

[0054] 3) Sample the input current i of the digital power communication module in , input current i in With input current reference value I Lref The error signal obtained from the comparison is passed through the P controller to obtain the duty cycle signal. This signal is compared with the triangular wave signal to obtain the drive PWM1 signal for the switching transistor S1.

[0055] Admittance correction control adjusts the on / off times of complementary conductions S2 and S3 to correct the input / output admittance of the auxiliary power supply in different modes. The degree of admittance correction can be controlled by changing the value of the admittance offset coefficient H. The specific control process is as follows:

[0056] 1) Voltage v across sampling capacitor C2 c2 , the capacitor voltage v c2 Its capacitor voltage reference value V c2_ref The error signal obtained from the comparison is then processed by the PI controller to obtain i. r2 ;

[0057] 2) The output capacitor C o voltage v o After filtering by a bandpass filter, the ripple signal is obtained. This signal is multiplied by the admittance offset coefficient H to obtain i. rip When the auxiliary power supply is operating in normal power supply mode and signal transmission mode, switch S d Closed, i r2 with i rip The summation yields the reference value I of the output current of the admittance correction module. L2ref When the auxiliary power supply is operating in signal receiving mode, switch S d Turn off, i r2 Directly used as the output current reference value I of the admittance correction module L2ref ;

[0058] 3) Sample the current i in inductor L2 L2 The signal is compared with its current reference value I. L2ref The error obtained from the comparison is processed by the P controller to obtain the duty cycle signal. The duty cycle signal is compared with the triangular wave signal to obtain the drive signal PWM2 for the switch S2. The inverted PWM2 is used to obtain the drive signal PWM3 for the switch S3.

[0059] Digital power demodulation operates in signal reception mode. Through signal processing, the characteristic current signal is restored to a digital signal, thus achieving signal reception. The specific operation steps are as follows:

[0060] 1) Input current i of the auxiliary power supplyin Input a bandpass filter to obtain the signal within the communication frequency band;

[0061] 2) Obtain a non-negative envelope signal by performing envelope detection on the communication frequency band signal obtained from the bandpass filter;

[0062] 3) The obtained envelope signal is sent to the sampling decision stage to obtain high and low level signals, which are eventually converted into "0" and "1" digital signals.

[0063] 3. In this embodiment of the invention, the digital power communication auxiliary power supply operating mode includes three operating modes: conventional power supply, signal transmission, and signal reception. These three operating modes can be selected via the control mode selection switch S. m and S d The switching is achieved by turning the device on and off, and the specific switching rules are as follows:

[0064] 1)S m =0&S d =0, the digital power communication auxiliary power supply operates in the normal power supply mode. At this time, the digital power communication auxiliary power supply only provides a high-quality 24V power supply voltage. This mode is the default operating mode.

[0065] 2)S m =1&S d =0, the digital power communication auxiliary power supply operates in signal transmission mode. At this time, the digital power communication auxiliary power supply injects a high-frequency characteristic current representing the signal into the DC bus, while providing a high-quality 24V power supply voltage.

[0066] 3)S m =0&S d =1, the digital power communication auxiliary power supply operates in signal receiving mode. At this time, the digital power communication auxiliary power supply increases the input admittance, thereby ensuring more signal flow, while providing a 24V power supply voltage.

[0067] Mode selection switch S m S d These are all virtual devices within the control system. Mode selection switch S m Corresponding to the first signal, mode selection switch S d This corresponds to the second signal.

[0068] In this embodiment of the invention, the gate of the switching transistor is the control electrode.

[0069] like Figure 3As shown, when a multi-node communication network is constructed using a digital power communication power supply with node signal enhancement, the auxiliary power supply connected in parallel on the same DC bus can be equivalent to different stages depending on its operating mode. In signal transmission mode, the transmitting node is equivalent to a controlled current source; in signal reception mode, the receiving node is equivalent to a high-admittance stage; and other unrelated nodes, operating in conventional power supply mode, are equivalent to a lower-admittance stage relative to the receiving node. In the entire communication network, because the receiving node has a higher admittance than other unrelated nodes, it can more easily obtain a larger high-frequency signal current, thereby improving communication reliability in multi-node, long-distance communication environments.

[0070] like Figure 4 As shown, when a digital power communication power supply with node signal enhancement is used to form a 3-node communication network, node 1 operates in transmitting mode, node 2 (an unrelated node) operates in conventional power supply mode, and node 3 operates in receiving mode. It can be seen that the current of the receiving node is significantly greater than that of the unrelated node.

Claims

1. A digital power communication power supply for enhancing node signals, characterized in that, include: A digital power communication module includes a resonant inductor, a resonant capacitor, and a high-frequency transformer; one end of the resonant inductor is connected to the positive terminal of a DC power supply, and the other end is connected to the positive terminal of the resonant capacitor and one end of the first winding of the high-frequency transformer; the other end of the first winding is connected to the drain of a first switching transistor; the negative terminal of the resonant capacitor and the source of the first switching transistor are connected to the negative terminal of the DC power supply. The admittance correction module includes an inductor. One end of the inductor is connected between one end of the second winding of the high-frequency transformer and the positive terminal of the output capacitor. The other end of the inductor is connected to the source of the second switching transistor and the drain of the third switching transistor. The drain of the second switching transistor is connected to one end of the third winding of the high-frequency transformer and the positive terminal of the second capacitor. The other end of the third winding, the source of the third switching transistor, the other end of the second winding, and the negative terminal of the second capacitor are all connected to the negative terminal of the output capacitor. One end of the second winding is connected to the anode of the first diode, and the cathode of the first diode is connected to the positive terminal of the output capacitor; A second diode is connected between the positive terminal of the second capacitor and one end of the third winding; The on / off control process of the second and third switching transistors includes: 1) Sample the voltage across the second capacitor. v c2 The voltage across the second capacitor v c2 With reference value of the second capacitor voltage V c2_ref The error information obtained from the comparison is then processed by the PI controller. i r2 ; 2) Sampling output capacitor output voltage v o , output voltage v o The filtered signal obtained after passing through the bandpass filter and the admittance offset coefficient H Multiply, we get i rip When the digital power communication power supply operates in both normal power supply mode and signal transmission mode, it will i r2 and i rip The summation yields the reference value of the output current of the admittance correction module. I L2ref When the digital power communication power supply is operating in signal receiving mode, it will... i r2 Directly used as the output current reference value of the admittance correction module I L2ref ; 3) Sample the inductor current of the admittance correction module as the output current of the admittance correction module. i L2 , output current i L2 With output current reference value I L2ref The error obtained from the comparison is processed by the P controller to obtain the duty cycle signal. The duty cycle signal is compared with the triangular wave signal to obtain the drive signal of the second switch. The drive signal of the second switch is inverted to obtain the drive signal of the third switch.

2. The digital power communication power supply for enhancing node signals according to claim 1, characterized in that, The on / off control process of the first switch includes: 1) Sampling output capacitor output voltage v o , output voltage v o With output voltage reference value V o_ref The error signal obtained from the comparison is then processed by a PI controller to obtain... i r1 ; 2) When the digital power communication power supply is operating in signal transmission mode, the high-frequency digital power communication signal is multiplied bit-by-bit by the binary communication data to be transmitted to obtain... i s ,Will i s and i r1 The sum is used to obtain the reference value of the input current of the digital power communication power supply. I Lref When the digital power communication power supply is operating in the normal power supply mode, it will i r1 Directly used as a reference value for the input current of digital power communication power supply I Lref ; 3) Sample the input current of the digital power communication power supply. i in , input current i in Compared with the input current reference value I Lref The error signal obtained from the comparison is passed through the P controller to obtain the duty cycle signal. The duty cycle signal is compared with the triangular wave to obtain the drive signal of the first switching transistor.

3. A digital power communication method for enhancing node signals as described in claim 1 or 2, characterized in that, The method includes: I) Sample digital power communication power supply input current i in , input current i in The signal within the communication frequency band is obtained by using a bandpass filter; II) Perform envelope detection on the signal within the communication frequency band to obtain a non-negative envelope signal; III) Sample and decide on the non-negative envelope signal to obtain high and low level signals, and convert the high and low level signals into "0" and "1" digital signals.

4. A method for switching the operating mode of a digital power communication power supply as described in claim 1 or 2, characterized in that, include: Given a first signal and a second signal, input the first signal and the second signal to the control system; When both the first and second signals are 0, the control system controls the digital power communication power supply to operate in the normal power supply mode. When the first signal is 1 and the second signal is 0, the control system controls the digital power communication power supply to work in signal transmission mode. When the first signal is 0 and the second signal is 1, the control system controls the digital power communication power supply to work in signal receiving mode. in, In normal power supply mode, the digital power communication power supply only provides the power supply voltage; In signal transmission mode, the digital power communication power supply injects a high-frequency characteristic current representing the signal into the DC bus, while simultaneously providing the power supply voltage; In signal reception mode, the digital power communication power supply increases the input admittance while providing the supply voltage.

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