CN105515611A

CN105515611A - APF (active power filter) communication system

Info

Publication number: CN105515611A
Application number: CN201510959585.4A
Authority: CN
Inventors: 花跃学; 葛文海; 仇志凌; 芮国强; 卢燕
Original assignee: NANJING APAITEK TECHNOLOGY Co Ltd
Current assignee: NANJING APAITEK TECHNOLOGY Co Ltd
Priority date: 2015-12-21
Filing date: 2015-12-21
Publication date: 2016-04-20

Abstract

The invention discloses an APF communication system, comprising a main module and n slave modules; the output end of the main module is divided into n ways respectively connected to every slave module; isolating LVDS circuits are arranged among the output end of the main module and the slave modules corresponding to the output end; the isolating LVDS circuits comprise isolating circuits and signal conversion circuits; the signals output by the main module are isolated by the isolating circuits to form single-ended signals; the single-ended signals are converted into LVDS signals through the conversion circuits; the LVDS signals are transmitted to the slave modules through network cables; the LVDS signals output by the slave modules are converted into single-ended signals through the conversion circuits, the single-ended signals are isolated by the isolating circuits and are transmitted to the main module through network cables. The system of the invention is featured by simple structure, reliable performance, low cost and low transmission delay.

Description

A kind of APF communication system

Technical field

Active Power Filter-APF (APF), as a kind of power electronic equipment improving the quality of power supply, became the focus of domestic and international power supply-distribution system harmonic suppression technique research in recent years.

Modular parallel technology conveniently can expand the capacity of current transformer, has simplicity of design, flexible for installation, the feature such as N+1 redundant attributes, high reliability, is widely used.

But in the connected mode that each is based on optical fiber at present mostly from the communication mode between module and primary module, number of fibers is more, and cost is very high, and transmission delay is larger.

Summary of the invention

The technical problem to be solved in the present invention be to provide a kind of reliably, low cost, communication system that transmission delay is little.

Technical scheme of the present invention is: a kind of APF communication system, comprise a primary module and n from module, the output of primary module divides n road, connect each respectively from module, what the output of described primary module was corresponding with this output isolates LVDS circuit from being also provided with between module, isolation LVDS circuit comprises buffer circuit and signaling conversion circuit, the signal that primary module exports is after buffer circuit isolation, form single-ended signal, single-ended signal to be converted to after LVDS signal by network cable transmission to from module by change-over circuit; After converting single-ended signal from the LVDS signal of module output to by change-over circuit, after buffer circuit isolation, by network cable transmission to primary module.

Adopt netting twine to replace existing optical fiber, not only save cost, simultaneously, because optical fiber needs first the signal of telecommunication to be converted to light signal, then light signal is converted to the signal of telecommunication, netting twine then directly transmits the signal of telecommunication, eliminate the time of signal conversion, make transmission delay little; Employing isolation LVDS circuit transmission data, well solve primary module and each is from the exchanges data problem between module, greatly reduce hardware cost, control the delay time of transmission at Microsecond grade while ensuring signal quality.

Further, described buffer circuit comprises power-switching circuit D1 and single-ended signal buffer circuit D2; Described change-over circuit comprises the single-ended LVDS of turning differential signal circuit U2, LVDS differential signal circuit and turns single-end circuit U1 and LVDS Signal reception terminating resistor circuit; The output of described D2 connects the input of D1, the transmitting terminal of D1 connects the input of U2, the output of U2 connects the receiving terminal from module, the input of LVDS Signal reception terminating resistor circuit is connected from the transmitting terminal of module, the output of LVDS Signal reception terminating resistor circuit connects the input of U1, and the output of U1 connects the receiving terminal of D1.By arranging power-switching circuit D1, the power supply of peripheral hardware and the controller circuitry of system are realized isolating on electrically, the branch circuit of electricity consumption and whole electrical system are isolated, make it to become segregate on electrically, an independently earth-free safety system, dangerous to prevent that Contact electricity occurs in the charged situation of bare exposed conductor fault.By arranging LVDS Signal reception terminating resistor circuit, convert LVDS current signal to voltage signal.

Further, described LVDS Signal reception terminating resistor circuit comprises two element circuits, and described element circuit comprises the identical resistance of two resistances and an electric capacity, and described resistance is connected in parallel on U1 and between module after mutually connecting, electric capacity one end ground connection, the other end connects in the middle of two resistance.The arranging of electric capacity can play the effect of filtering common mode interference, makes signal more accurate.

Advantage of the present invention is: structure is simple, dependable performance, low cost, transmission delay are little.

Accompanying drawing explanation

Fig. 1 is general hardware structured flowchart of the present invention.

Fig. 2 is that the present invention isolates LVDS circuit block diagram.

Fig. 3 is the circuit diagram that the present invention isolates LVDS circuit.

Embodiment

Below in conjunction with accompanying drawing, the invention will be further described.

As shown in Figure 1, the present invention includes a primary module and n from module, the output of primary module divides n road, connect each respectively from module, what the output of described primary module was corresponding with this output isolates LVDS circuit from being also provided with between module, and isolation LVDS circuit comprises buffer circuit and signaling conversion circuit, and the signal that primary module exports is after buffer circuit isolation, form single-ended signal, single-ended signal to be converted to after LVDS signal by network cable transmission to from module by change-over circuit; After converting single-ended signal from the LVDS signal of module output to by change-over circuit, after buffer circuit isolation, by network cable transmission to primary module.

As shown in Figure 2, described buffer circuit comprises power-switching circuit D1 and single-ended signal buffer circuit D2; Described change-over circuit comprises the single-ended LVDS of turning differential signal circuit U2, LVDS differential signal circuit and turns single-end circuit U1 and LVDS Signal reception terminating resistor circuit; The output of described D2 connects the input of D1, the transmitting terminal of D1 connects the input of U2, the output of U2 connects the receiving terminal from module, the input of LVDS Signal reception terminating resistor circuit is connected from the transmitting terminal of module, the output of LVDS Signal reception terminating resistor circuit connects the input of U1, and the output of U1 connects the receiving terminal of D1.

As shown in Figure 3, be the hardware elementary diagram of isolation LVDS circuit, mainly comprise insulating power supply conversion, single-ended signal isolation, the single-ended LVDS of turning differential signal, LVDS differential signal turn single-ended signal, LVDS Signal reception terminating resistor circuit.

Wherein insulating power supply conversion D2, is in figure, (D1 secondary, U1, U2) provides power supply, realizes isolating with controller circuitry on electrically simultaneously.The 3.3V_ISO that to be the right of controller 3.3V and digitally DGND, chip D2 be the left side of chip D2 after isolation and isolator DGND_ISO.

Wherein single-ended signal isolating chip D1 is the isolation of controller signals, and the chip D1 left side is the signal (comprising transmission and Received signal strength) of controller, and the right is the signal after isolation.Send signal TX1, TX2 and become TX1_ISO, TX2_ISO signal after isolation, access and single-endedly turn LVDS difference channel U2.

The single-ended LVDS difference channel U2 that turns is by differential signal TX1_ISO_LVDSN and TX1_ISO_LVDSP of the TX1_ISO signal conversion after isolation; By differential signal TX2_ISO_LVDSN and TX2_ISO_LVDSP that TX2_ISO signal is changed.

Wherein J1A is the RJ45 connector of non-isolated.For primary module signal is sent to from module by netting twine, simultaneously by Signal reception from module to primary module that send in primary module.

LVDS Signal reception terminating resistor circuit (R1, R2, C1), (R3, R4, C2) converts 2 groups of LVDS current signals to voltage signal respectively, and wherein electric capacity can play the effect of filtering common mode interference.LVDS difference turns single-ended chip U1 and converts the 2 road differential signals received to 2 single-ended signals RX1_ISO, RX2_ISO again.RX1_ISO, RX2_ISO are linked on signal isolating chip D1 again, become RX1, RX2 and be linked in controller after D1 isolation.

Claims

1. an APF communication system, it is characterized in that: comprise a primary module and n from module, the output of primary module divides n road, connect each respectively from module, what the output of described primary module was corresponding with this output isolates LVDS circuit from being also provided with between module, isolation LVDS circuit comprises buffer circuit and signaling conversion circuit, the signal that primary module exports is after buffer circuit isolation, form single-ended signal, single-ended signal to be converted to after LVDS signal by network cable transmission to from module by change-over circuit; After converting single-ended signal from the LVDS signal of module output to by change-over circuit, after buffer circuit isolation, by network cable transmission to primary module.

2. a kind of APF communication system according to claim 1, is characterized in that: described buffer circuit comprises power-switching circuit D1 and single-ended signal buffer circuit D2; Described change-over circuit comprises the single-ended LVDS of turning differential signal circuit U2, LVDS differential signal circuit and turns single-end circuit U1 and LVDS Signal reception terminating resistor circuit; The output of described D2 connects the input of D1, the transmitting terminal of D1 connects the input of U2, the output of U2 connects the receiving terminal from module, the input of LVDS Signal reception terminating resistor circuit is connected from the transmitting terminal of module, the output of LVDS Signal reception terminating resistor circuit connects the input of U1, and the output of U1 connects the receiving terminal of D1.

3. a kind of APF communication system according to claim 2, it is characterized in that: described LVDS Signal reception terminating resistor circuit comprises two element circuits, described element circuit comprises the identical resistance of two resistances and an electric capacity, described resistance is connected in parallel on U1 and between module after mutually connecting, electric capacity one end ground connection, the other end connects in the middle of two resistance.