CN102624427B - Synchronous transmission system of energy and information - Google Patents

Abstract

The invention discloses a synchronous transmission system of energy and information, which comprises a direct current bus, a direct current power supply and a plurality of energy information transmission units, and the direct current power supply and the plurality of energy information transmission units are connected with the direct current bus. Each energy information transmission unit comprises a Boost circuit, a sampling circuit, a carrier detecting circuit, a control circuit and a driving circuit. The synchronous transmission system of the energy and the information enables power line carrier communication technology to be combined with characteristics of the Boost circuits, achieves synchronous transmission of the energy and the information under the premise that circuit modulation is not required additionally, volume of the system and use of corresponding devices are reduced, extra connecting lines are not required, and characteristics of communication channels can be designed according to requirements.

Description

A Synchronous Transmission System of Energy and Information

technical field

The invention belongs to the technical field of power electronic communication, and in particular relates to a synchronous transmission system of energy and information.

Background technique

With the rapid development of electronic technology, new concepts such as the Internet of Things are gradually being accepted by people. Whether it is a different power conversion system or a different power conversion module in the same system, in order to achieve the intended function, in addition to the need for the power supply to provide electric energy, it also requires the cooperation and coordination of the communication function between each other.

In power electronics technology, the DC-DC (direct current-direct current) converter originally only realizes the conversion and transmission of energy by controlling the opening and closing of the switching tube. When a system has multiple DC-DC converters powering different devices, it is often necessary to add a communication function to transfer information between each DC-DC converter and coordinate work.

Facing the two different functional requirements of energy transmission and signal communication, the traditional solution generally uses two sets of different hardware circuits to handle the functions of energy transmission and information transmission respectively; this traditional design scheme uses many components and is bulky Larger, requires additional cable.

At present, in the field of communication, power line carrier communication (PLC) technology has been widely researched and applied. It superimposes the carrier signal on the power line, and transmits data through the existing power line, avoiding additional wiring. However, the realization of power line carrier communication often requires an additional carrier modulation circuit, which includes a coupling transformer, which is large in size and high in cost; at the same time, traditional power line carrier communication is to superimpose digital signals on existing power lines for communication. The energy of the channel is not controlled, and the characteristics of the channel cannot be changed.

The Chinese patent with application number 200910191716.3 discloses a device and method for synchronous transmission of energy signals. This technology adds a signal modulator to the main circuit and a signal extraction and recovery circuit to the secondary circuit, which is the same as the power line carrier communication. An additional signal modulator needs to be added, which increases the volume and cost of the circuit, and is only used to adjust the injected energy of the system.

Contents of the invention

Aiming at the above-mentioned technical defects in the prior art, the present invention provides a synchronous transmission system of energy and information, which realizes the synchronous transmission of energy and information without additional modulation circuits.

A synchronous transmission system of energy and information, comprising: a DC power supply, a DC bus, and several energy information transmission units connected to corresponding loads; the DC power supply and the energy information transmission unit are both connected to the DC bus .

The energy information transmission unit includes:

Boost (boost) circuit, boosts the DC power on the DC bus and sends it to the load, and generates harmonic signals to the DC bus;

The sampling circuit collects the state signal of the load; the state signal includes state information such as a current signal and a voltage signal;

The carrier detection circuit receives the harmonic signals generated by other energy information transmission units from the DC bus, and outputs the carrier signal after filtering and amplifying the harmonic signals;

The control circuit sequentially performs analog-to-digital conversion and analysis and identification on the carrier signal or state signal, and constructs a switch signal according to the identification result;

The driving circuit performs power amplification on the switch signal, and uses the power amplified switch signal to control the switch tube in the Boost circuit.

Preferably, the Boost circuit includes an inductor, a capacitor and two switch tubes; wherein, one end of the inductor is connected to the DC bus, and the other end is connected to the drain of the first switch tube and the drain of the second switch tube; The source of the second switching tube is connected to one end of the capacitor and one end of the load; the source of the first switching tube is connected to the other end of the capacitor and the other end of the load and grounded; the gate of the first switching tube or the second switching tube Receive the amplified switching signal output by the driving circuit; it can prevent the Boost circuit from entering the discontinuous working mode from affecting the current waveform on the inductor.

The switching signals received by the first switch tube and the second switch tube are complementary.

Preferably, the DC power supply is connected to the DC bus through an impedance matching network; interference to communication can be weakened.

The impedance matching network includes an inductor, a capacitor and a resistor; wherein, one end of the inductor is connected to the positive pole of the DC power supply, and the other end is connected to one end of the capacitor; the other end of the capacitor is connected to one end of the resistor, and the other end of the resistor Connect to the negative terminal of the DC power supply and ground.

Preferably, the control circuit is connected to a man-machine interface; so that the user can control the system.

The control circuit constructs a corresponding switching signal by adjusting the duty cycle or switching frequency according to the identification result; wherein:

For energy transmission, make the switching frequency of the switching signal constant and adjust the duty cycle of the switching signal;

For information transmission, the duty ratio of the switching signal is kept constant, and the switching frequency of the switching signal in each chip period is adjusted; the chip period is an integer multiple of the switching period.

The control circuit is a DSP (Digital Signal Processor).

The invention combines the power line carrier communication technology with the characteristics of the Boost circuit, realizes the synchronous transmission of energy and information without additional modulation circuits, reduces the volume of the system and the use of corresponding components, and does not require additional connecting lines , and the characteristics of the communication channel can also be designed according to the needs.

At the same time, when the present invention is applied to LED lighting systems, electric vehicles, power supply systems with multiple output requirements, new energy grid-connected power generation, etc., only one dedicated line can be used to transmit energy and signals at the same time without adding additional modulation circuits; Therefore, the present invention can conveniently realize centralized control and operating state detection, and the amplitude of the carrier signal is stable, independent of the load current, only related to the input voltage and output voltage.

Description of drawings

Fig. 1 is a schematic structural diagram of the system of the present invention.

Figure 2 is a schematic structural diagram of the carrier detection circuit.

FIG. 3 is a schematic diagram of waveforms of switching signals and harmonic signals.

Detailed ways

In order to describe the present invention more specifically, the technical solutions of the present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

Apply the present invention to an LED lighting system, as shown in Figure 1, a synchronous transmission system of energy and information, comprising: a DC power supply E, a DC bus and n energy information transmission units connected to the corresponding load; n Each energy information transmission unit is connected to the DC bus; the load in this embodiment is LED (Light Emitting Diode).

The DC power supply E is connected to the DC bus through an impedance matching network; the impedance matching network includes an inductor Lr, a capacitor Cr and a resistor Rr; wherein, one end of the inductor Lr is connected to the positive pole of the DC power supply E, and the other end is connected to one end of the capacitor Cr The other end of the capacitor Cr is connected to one end of the resistor Rr, and the other end of the resistor Rr is connected to the negative pole of the DC power supply E and grounded.

The energy information transmission unit includes Boost circuit, sampling circuit, carrier detection circuit, driving circuit and DSP; where:

The Boost circuit is used to boost the DC power on the DC bus and send it to the LED, and generate harmonic signals to the DC bus; in this embodiment, the Boost circuit includes an inductor L, a capacitor C and two switch tubes Q1~Q2 ; Wherein, one end of the inductor L is connected to the DC bus, and the other end is connected to the drain of the first switching tube Q1 and the drain of the second switching tube Q2; the source of the second switching tube Q2 is connected to one end of the capacitor C and the LED The anode is connected; the source of the first switching tube Q1 is connected to the other end of the capacitor C and the cathode of the LED and is grounded; the gates of the first switching tube Q1 and the second switching tube Q2 are both receiving the amplified power output from the driving circuit. Signal; the switching signals received by the first switch tube Q1 and the second switch tube Q2 are complementary.

The sampling circuit is used to collect the current signal of the LED; in this embodiment, the sampling circuit is a current sensor.

The carrier detection circuit is used to receive the harmonic signal generated by other energy information transmission units from the DC bus, and output the carrier signal after filtering and amplifying the harmonic signal; as shown in Figure 2, in this embodiment, the carrier detection circuit includes Five resistors R1~R5, three capacitors C1~C3 and an operational amplifier LM318; among them: one end of C1 is connected to the DC bus, and the other end is connected to R1; the other end of R1 is connected to R2, R3 and the positive phase input end of LM318; the other end of R2 And the positive power supply terminal of LM318 is connected to VCC; the other end of R3 is connected to C2 and grounded; the other end of C2 is connected to R4; the other end of R4 is connected to R5, C3 and the inverting input terminal of LM318; The other end of R5 is connected to the other end of C3 in parallel with DSP.

DSP is used to perform analog-to-digital conversion and analysis and identification on the carrier signal or current signal in sequence, and construct the corresponding switching signal by adjusting the duty ratio or switching frequency; among them: for energy transmission, the switching frequency of the switching signal is kept constant, and the adjustment The duty cycle of the switching signal; for information transmission, the duty cycle of the switching signal is kept constant, and the switching frequency of the switching signal in each chip period is adjusted. In this embodiment, the DSP adopts TMS320F28035; wherein, the DSP in the first energy information transmission unit is also connected to a man-machine interface.

The driving circuit is used to amplify the power of the switching signal, and use the amplified switching signal to control the switching tubes Q1-Q2 in the Boost circuit; in this embodiment, the driving circuit uses the chip IR2101.

In this embodiment, the current sensor collects the current signal (6A) of the LED, and the DSP performs analog-to-digital conversion of the current signal 6→110; in order not to affect the energy transmission, the DSP keeps the duty cycle of the switching signal constant, as shown in Figure 3 It shows that the three digital quantities of 110 respectively correspond to three consecutive chip periods, and the DSP adjusts the switching frequency of the switching signal in each chip period, wherein the switching frequency of the first two chip periods is f ₁ , Let the switching frequency of the last chip period be f ₂ (f ₂ =2f ₁ ), construct the corresponding switching signal to control the switching tube in the Boost circuit, and then control the harmonic frequency generated by the Boost circuit, The harmonic can be used as the carrier signal for communication; in the figure, s ₁ is the switching signal of the first switching tube Q1 in the Boost circuit, and i _L is the current signal of the inductor L in the Boost circuit (that is, the harmonic signal generated by the Boost circuit).

In the energy information transmission unit, the Boost circuit is used as a DC-DC circuit for power conversion and transmission to supply power to the LED; at the same time, the Boost circuit will generate certain harmonics at the input end, similar to the communication carrier, the harmonic signal can be transmitted by the same DC It is detected by other units under the bus; by controlling the harmonic spectrum generated by this unit without affecting the energy transmission of the Boost circuit, the harmonic component can be used as a carrier for communication, so that the system realizes the synchronization of energy and information transmission.

Claims (8)

1. the synchronous transmission system of an energy and information, is characterized in that: comprise a direct current power supply, a direct current bus and energy information transmission unit some and that corresponding load is connected; Described DC power supply and energy information transmission unit all are connected on described DC bus;

Described energy information transmission unit comprises:

The Boost circuit, flow to load after the direct current on DC bus is boosted, and produce harmonic signal to DC bus;

Sample circuit, the status signal of collection load;

Carrier detecting circuit, receive from DC bus the harmonic signal that other energy information transmission units produce, and this harmonic signal is carried out to outgoing carrier signal after filter and amplification;

Control circuit, carry out successively analog-to-digital conversion and analyze identification described carrier signal or status signal, according to recognition result, constructs switching signal;

Drive circuit, carry out power amplification to described switching signal, and utilize the switching signal after power amplification to be controlled the switching tube in the Boost circuit.

2. the synchronous transmission system of energy according to claim 1 and information, it is characterized in that: described Boost circuit comprises an inductance, an electric capacity and two switching tubes; Wherein, an end of inductance is connected with DC bus, and the other end is connected with the drain electrode of second switch pipe with the drain electrode of the first switching tube; The source electrode of second switch pipe is connected with an end of electric capacity and an end of load; The source electrode of the first switching tube is connected with the other end of the other end of electric capacity and load and ground connection; Switching signal after the power amplification of the grid reception drive circuit output of the first switching tube or second switch pipe.

3. the synchronous transmission system of energy according to claim 2 and information, is characterized in that: the switching signal complementation that described the first switching tube and second switch pipe receive.

4. the synchronous transmission system of energy according to claim 1 and information, it is characterized in that: described DC power supply is connected on DC bus by impedance matching network.

5. the synchronous transmission system of energy according to claim 4 and information, it is characterized in that: described impedance matching network comprises an inductance, an electric capacity and a resistance; Wherein, an end of inductance is connected with the positive pole of DC power supply, and the other end is connected with an end of electric capacity; The other end of electric capacity is connected with an end of resistance, and the other end of resistance is connected with the negative pole of DC power supply and ground connection.

6. the synchronous transmission system of energy according to claim 1 and information, it is characterized in that: described control circuit is connected with man-machine interface.

7. the synchronous transmission system of energy according to claim 1 and information, it is characterized in that: described control circuit is according to recognition result, by duty ratio or switching frequency adjustment are constructed to corresponding switching signal; Wherein:

For Energy Transfer, make the switching frequency of switching signal constant, adjust the duty ratio of switching signal;

For communication, make the duty ratio of switching signal constant, adjust the switching frequency of switching signal in each chip period.

8. according to the synchronous transmission system of claim 1,6 or 7 described energy and information, it is characterized in that: described control circuit is DSP.

Images