CN201742296U - Power communication line multiplexing circuit based on forward topology - Google Patents

Abstract

The utility model discloses a power supply communication line multiplexing circuit based on forward topology, which comprises a power supply, a transformer connected to the power supply and an output circuit, and is characterized in that: the input winding (1) end of the transformer is connected in series with a MOSFET The DC power supply (16) connection line of the switch tube (15) is set as a remote communication line; a reset winding (2) is connected in series with the output winding (3) of the transformer; and a data reading device is connected to the output winding (3) of the transformer The circuit (A) and the data sending circuit (B); the data reading circuit and the data sending circuit are connected with the control unit DSP (10). The circuit can complete the functions of feeding back data and reading data to the multiplexing bus, realizing multi-computer communication; realizing power isolation, and the circuit feeds the magnetic reset energy to the load side in each cycle by setting the magnetic reset winding.

Description

A Power Communication Line Multiplexing Circuit Based on Forward Topology

technical field

The utility model relates to a forward circuit, in particular to a power supply communication multiplexing circuit with dual functions of long-distance power supply and communication.

Background technique

In the field of new energy research, in order to ensure the safe and reliable operation of the micro-grid, the inverter unit, load unit, and energy storage unit contained in the micro-grid all need independent control circuits, which involves how to supply power to these control circuits. . At the same time, necessary communication is required between each control unit and with the upper control unit. Usually, for a complete micro-grid, it is necessary to provide each control unit with a power line, a ground wire, and a data line for receiving and sending data. At least four lines are required, and the cost is relatively high. Moreover, the control circuit will share the same ground, which is safe and reliable. Low.

Contents of the invention

The purpose of this utility model is to provide a power supply communication line multiplexing circuit based on forward topology, which can complete the functions of feeding back data to the multiplexing bus and reading data, realizing multi-machine communication; realizing power isolation, and the circuit The magnetic reset energy is fed to the load side in each cycle by setting the magnetic reset winding.

The purpose of this utility model is achieved through the following technical solutions, a power supply communication line multiplexing circuit based on forward topology, including a power supply and a transformer connected to the power supply and an output circuit, characterized in that: the input winding of the transformer The connection line between the terminal and the DC power supply with a MOSFET switch tube connected in series is set as a remote communication line; a magnetic reset winding is connected in series on the output winding of the transformer; and a data reading circuit and a data sending circuit are connected at the output winding end of the transformer ; Data reading circuit, data sending circuit and connected with the control unit DSP.

The length of the long-distance communication line is 500-1000m.

The magnetic reset winding is connected in series with a diode, and the diode is connected with the capacitor of the output circuit.

The data reading circuit includes a voltage dividing resistor, a comparator and a reference voltage. The two voltage dividing resistors are connected in series on the transformer output winding voltage detection point, the comparator is connected between the two voltage dividing resistors, and the output terminal of the comparator is connected to the control The unit DSP is connected; the reference voltage is connected to the comparator.

The data sending circuit includes a PNP transistor and a PNP transistor, the PNP transistor is connected to the output winding of the transformer and the capacitor of the output circuit; the PNP transistor is connected to the PNP transistor and connected to the control unit DSP.

A voltage stabilizing chip is connected between the output winding of the transformer and the control unit DSP.

A bias resistor is connected between the respective bases and emitters of the PNP triode and the PNP triode respectively.

The remote communication line of the DC power supply connected in series with MOSFET switch tubes is connected with 1-5 power supply communication line multiplexing circuits.

Inspired by the forward circuit, the utility model proposes a new power supply and communication multiplexing circuit, and simultaneously realizes power supply isolation. The utility model utilizes the working principle of the forward switching power supply, installs the transformer and its output part of the single-ended forward switching power supply near the power supply unit, and the input DC power supply and the switching tube can be installed in different places. The multiplexed bus can supply power to multiple slaves. In a microgrid system, with this power supply technology, only two wire connections are required between the control units. At the same time, by controlling the data transmission and reading circuit on the output winding side of the isolation transformer, the functions of data feedback and reading data to the multiplexing bus can be completed, and multi-machine communication can be realized. The magnetic reset winding of the transformer can feed the magnetic reset energy to the load side in each cycle.

Description of drawings

Figure 1 is a schematic circuit diagram of power supply communication multiplexing; Figure 2 is a schematic diagram of multi-machine power supply communication topology.

In the figure: 1. Input winding; 2. Magnetic reset winding; 3. Output winding; 4. Voltage dividing resistor; 5. Comparator; 6. Reference voltage; 7. First PNP transistor; 8. Second PNP transistor; 9 , Voltage regulator chip; 10, DSP controller; 11, Control data output pin; 12, Judgment input data pin; 13, Power supply port; 14, Transformer output winding voltage detection point; 15, MOSFET switch tube; 16, DC power supply.

Detailed ways

The circuit of the present invention: power supply, data reading, data sending, and realization of magnetic reset functions will be further described below through specific embodiments.

As shown in Figure 1, the power supply communication line multiplexing circuit based on the forward topology includes a power supply, a transformer connected to the power supply and an output circuit, wherein: the input winding terminal 1 of the transformer is connected to the DC power supply with a MOSFET switch tube 15 connected in series The connection line between 16 is set as a long-distance communication line, and the length of the long-distance communication line is 500-1000m; the optimal length of this embodiment is 1000m.

The utility model also adds a magnetic reset winding 2 at the output end of the original forward topology circuit transformer, and connects a data reading circuit A and a data sending circuit B in parallel on the output circuit; and the data reading circuit A and the The output end of the data sending circuit B is connected with the control unit DSP 10. A voltage stabilizing chip (7805) 9 is set between the transformer output terminal and the control unit DSP 10, the input terminal of the voltage stabilizing chip (7805) 9 is connected to the positive pole of the output capacitor in the output circuit, and the output terminal is connected to the power supply of the control unit DSP10 Port 13 is connected, and the ground terminal is connected to the negative pole of the output capacitor.

In the above circuit, the magnetic reset winding 2 is connected in series with a diode, the positive pole of the diode is connected to the opposite terminal of the magnetic reset winding 2, and the negative pole is connected to the positive pole of the output capacitor.

Among them, the data reading circuit A includes a voltage dividing resistor 4, a comparator 5 and a reference voltage 6, and the two voltage dividing resistors 4 are connected in series on the voltage detection point 14 of the transformer output winding of the transformer output winding 3 with the same name, and the negative terminal of the comparator 5 The input is connected between the two voltage dividing resistors 4, the positive terminal input is connected with the reference voltage 6, and the output terminal of the comparator 5 is connected with the judgment input data pin 12 of the control unit DSP 10.

The data sending circuit B includes a PNP transistor 7 and a PNP transistor 8, the collector of the PNP transistor 8 is connected to the terminal of the same name of the transformer output winding 3 through a collector resistor, the emitter is connected to the positive pole of the capacitor of the output circuit, and the emitter of the PNP transistor 8 is connected to the base A bias resistor is connected between the poles. The emitter of PNP transistor 7 is connected to the base of PNP transistor 8, the collector of PNP transistor 7 is grounded through a resistor, the base is connected to the control data output pin 11 of the control unit DSP 10 through a base resistor, and the emitter of PNP transistor 7 is connected to the base. A bias resistor is connected between the poles.

As shown in Figure 2, there are 1-5 long-distance power supply communication circuits connected to the remote communication line of the DC power supply 16 connected in series with the MOSFET switch tube 15, and the present embodiment provides a remote communication line connected with 3 A power communication line multiplexing circuit.

The working principle of the present utility model is: 1. supply power to the MOSFET switching tube 15 in Fig. 1. A fixed duty ratio is a 1/4 drive waveform, so that the DC power supply 16 produces a voltage with a duty ratio of 1/4 at the transformer input winding 1. At the same time, a voltage waveform with the same duty ratio is induced on the output winding 3, and a relatively stable voltage is generated at the input terminal of the voltage stabilizing chip (7805) 9. By adjusting the DC power supply 16 , the voltage can be kept between 5V and 18V, so as to ensure that the voltage stabilizing chip 9 generates a stable 5V voltage to supply power to the power supply port 13 . The magnetic reset energy provided by the magnetic reset winding 2 can be fed to the input side of the voltage stabilizing chip 9 to balance it within a voltage range. As long as it is ensured that the fluctuation of this voltage does not exceed a given range, the stable power supply of the DSP controller 10 can be guaranteed.

2 Data transmission When sending data bit "1", set the output pin 11 low in the second 1/4 cycle of the switching cycle, and the PNP transistor 7 and PNP transistor 8 will be turned on one after another. At this time, the voltage regulator chip 9 The input side of the transformer feeds power to the transformer output winding voltage detection point 14 to generate a high level. In this way, the high level is transmitted to the multiplexing bus of the power communication line through the transformer, and can be read by other units.

3. The data reading transformer output winding voltage detection point 14 is connected to the voltage divider resistor 4, and the high potential of their midpoint voltage is set to 5V by designing the resistance value of the voltage divider resistor, and the midpoint voltage is compared with the reference voltage 6 by the comparator 5. The output result of the comparator 5 can determine whether the transformer output winding voltage detection point 14 is a high potential or a low potential; the control unit DSP 10 reads and judges the value of the input data pin 12 in the second 1/4 cycle of each switching cycle, thereby It is known whether the data represented by the switching cycle is "1" or "0".

4 Magnetic reset The magnetic reset time accounts for the second half of each switching cycle. When the switch tube 15 is turned off and the PNP transistor 8 is turned off, the excitation energy can be released through the reset winding during this period. This is used on the one hand to prevent saturation of the transformer and on the other hand to feed energy to the load. The reason why the magnetic reset winding 2 is not connected to the positive terminal of the input power supply as in the traditional forward excitation is because under the condition of long-distance communication, the energy feedback to the power supply will increase the line loss, and at the same time, it is easy to interfere with data transmission.

Claims (8)

1. power supply order wire multiplex circuit based on forward topology, comprise power supply and the transformer and the output circuit that link to each other with power supply, it is characterized in that: the connecting line that the DC power supply (16) of switch mosfet pipe (15) was held and be serially connected with to the input winding (1) of described transformer is set to the telecommunication line; On the output winding (3) of transformer, be serially connected with a magnetic reset winding (2); And be connected with data reading circuit (A) and data transmit circuit (B) at this transformer output winding (3) end; Data reading circuit (A), data transmit circuit (B) also link to each other with control unit DSP (10).

2. a kind of power supply order wire multiplex circuit based on forward topology according to claim 1, it is characterized in that: described telecommunication line length is 500～1000m.

3. a kind of power supply order wire multiplex circuit based on forward topology according to claim 1 is characterized in that: described magnetic reset winding (2) serial connection one diode, this diode also links to each other with the electric capacity of output circuit.

4. a kind of power supply order wire multiplex circuit according to claim 1 based on forward topology, it is characterized in that: described data reading circuit (A) comprises divider resistance (4), comparator (5) and reference voltage (6), two divider resistances (4) are serially connected on the transformer output winding voltage test point (14), comparator (5) is connected between two divider resistances (4), and comparator (5) output links to each other with control unit DSP (10); Reference voltage (6) is connected on the comparator (5).

5. a kind of power supply order wire multiplex circuit according to claim 1 based on forward topology, it is characterized in that: described data transmit circuit (B) comprises PNP triode (7) and PNP triode (8), and PNP triode (8) is connected on the electric capacity of transformer output winding (3) and output circuit; PNP triode (7) is connected on the PNP triode (8), and links to each other with control unit DSP (10).

6. a kind of power supply order wire multiplex circuit based on forward topology according to claim 1 is characterized in that: be connected with voltage stabilizing chip (9) between described transformer output winding and the control unit DSP (10).

7. a kind of power supply order wire multiplex circuit based on forward topology according to claim 5 is characterized in that: be connected a biasing resistor respectively between described PNP triode (8), PNP triode (7) base stage separately and the emitter.

8. a kind of power supply order wire multiplex circuit based on forward topology according to claim 1 is characterized in that: be connected with 1-5 power supply order wire multiplex circuit on the telecommunication line of the described DC power supply (16) that is serially connected with switch mosfet pipe (15).

Images