The level lifting circuit that is used for the distribution transformer long distance control systemTechnical field
The present invention relates to the auxiliary system of distribution transformer, specifically is the level lifting circuit for the distribution transformer long distance control system.
Background technology
Along with industrial expansion, all trades and professions improve day by day to the power supply reliability of electric power system and the requirement of stability, distribution transformer is as the core link of electric power system, and it is the power equipment of electric energy directly being distributed to low-voltage customer, and its service data is the basic data of whole power distribution network.Therefore, the safe operation of distribution transformer is most important to electric power system.For distribution transformer is monitored, existing distribution power transformation device generally is equipped with the supervisory control system based on radio communication, supervisory control system is usually come analyzing and processing by voltage or the current signal that instrument transformer obtains distribution transformer, and then realizes the remote monitoring to distribution power transformation device.Single-chip microcomputer is with low cost, the controller of existing distribution power transformation device supervisory control system often adopts chip microcontroller, but when the signal of telecommunication that distribution power transformation device supervisory control system is obtained distribution transformer by instrument transformer is realized monitoring, there is positive negative characteristic in the AC signal of instrument transformer secondary output, and the analog-to-digital conversion module in the existing single-chip microcomputer generally can only be handled the forward signal of telecommunication, existing distribution power transformation device supervisory control system is usually set up complicated circuit and is realized instrument transformer and single-chip microcomputer compatibility, and this has increased the cost of distribution power transformation device supervisory control system on the contrary.
Summary of the invention
The objective of the invention is to overcome the deficiencies in the prior art, a kind of level lifting circuit for the distribution transformer long distance control system is provided, it is simple in structure, the use element is few, cost is low, and the signal boost that instrument transformer can be obtained is in the positive interval, so be convenient to single-chip microcomputer constitutes in the distribution power transformation device supervisory control system controller to signal mode number conversion carry out the processing of postorder.
Purpose of the present invention is achieved through the following technical solutions: the level lifting circuit that is used for the distribution transformer long distance control system, comprise and gather signal input line, superposed signal input line, first resistance, second resistance, the 5th resistance and first operational amplifier, the described second resistance two ends are connected with the first operational amplifier in-phase input end with the collection signal input line respectively, described first resistance, one end is connected on the circuit between second resistance and the first operational amplifier in-phase input end, and its other end is connected with the superposed signal input line; Described the 5th resistance one end is connected with first operational amplifier output terminal, and its other end is connected with output line.When the present invention uses, gather signal input line and be used for receiving the signal that instrument transformer collects, the superposed signal input line is used for the direct current signal of input stack, and output line then is used for rising to the signal output in the positive interval.
First operational amplifier of the present invention both can adopt common source with other element in the supervisory control system, also can adopt independent current source, and for the ease of independent control power supply, as preferably, described first operational amplifier is connected with power supply.
Be used for the level lifting circuit of distribution transformer long distance control system, also comprise the 4th resistance, described the 4th resistance two ends are connected with output with the first operational amplifier inverting input respectively.
Be used for the level lifting circuit of distribution transformer long distance control system, also comprise the 3rd resistance, described the 3rd resistance one end is connected its other end ground connection with the first operational amplifier inverting input.
As preferably, the resistance of described first resistance, second resistance, the 3rd resistance and the 4th resistance is identical.
Compared with prior art, the present invention has following beneficial effect: the present invention includes the collection signal input line, the superposed signal input line, first resistance, second resistance, the 5th resistance and first operational amplifier, when using, the present invention imports the signal that instrument transformer obtains by gathering signal input line, and imported the direct current signal of required stack by the superposed signal input line, through generating the signal that is positioned at positive interval after the first operational amplifier overlap-add procedure, the controller of the distribution transformer supervisory control system that this signal is made of output line input single-chip microcomputer, and then can be by the processing of carrying out postorder after the analog-to-digital conversion module converts in the single-chip microcomputer; The present invention uses element few when realizing instrument transformer and single-chip microcomputer compatibility, and cost is low, and then the cost of distribution power transformation device supervisory control system is reduced.
Description of drawings
Fig. 1 is the structural representation of the embodiment of the invention.
The corresponding name of Reference numeral is called in the accompanying drawing: 1, gather signal input line, and 2, the superposed signal input line, 3, output line, R1, first resistance, R2, second resistance, R3, the 3rd resistance, R4, the 4th resistance, R5, the 5th resistance, VCC, power supply, A1, first operational amplifier.
Embodiment
The present invention is described in further detail below in conjunction with embodiment and accompanying drawing, but embodiments of the present invention are not limited thereto.
Embodiment
As shown in Figure 1, the level lifting circuit that is used for the distribution transformer long distance control system, comprise and gather signal input line 1, superposedsignal input line 2, first resistance R 1,second resistance R 2, the3rd resistance R 3, the 4th resistance R 4, the 5th resistance R 5 and first operational amplifier A 1, wherein, first operational amplifier A 1 is connected with power supply VCC and is provided with ground path.Second resistance R, 2 two ends are connected with first operational amplifier A, 1 in-phase input end with collection signal input line 1 respectively, first resistance R, 1 one ends are connected on the circuit betweensecond resistance R 2 and first operational amplifier A, 1 in-phase input end, and its other end is connected with superposedsignal input line 2; The 5th resistance R 5 one ends are connected with first operational amplifier A, 1 output, and its other end is connected withoutput line 3.
The 4th resistance R 4 two ends are connected with output with first operational amplifier A, 1 inverting input respectively, and the3rd resistance R 3 one ends are connected its other end ground connection with first operational amplifier A, 1 inverting input.As preferably, the resistance of first resistance R 1,second resistance R 2, the3rd resistance R 3 and the 4th resistance R 4 four is identical.
Collection signal input line 1 connect instrument transformer and imports the signal that instrument transformer collects when present embodiment was used, superposedsignal input line 2 is used for the dc current signal of input stack, gather the signal ofsignal input line 1 and 2 both inputs of superposed signal input line and exported byoutput line 3 after first operational amplifier A 1 is handled, present embodiment guarantees that by the signal of control superposedsignal input line 2 inputs the signal waveform ofoutput line 3 outputs is in the positive interval.
Above content be in conjunction with concrete preferred implementation to further describing that the present invention does, can not assert that the specific embodiment of the present invention is confined to these explanations.For the general technical staff of the technical field of the invention, not breaking away from other execution modes that draw under the technical scheme of the present invention, all should be included in protection scope of the present invention.