CN107508381A - One kind is used for active power distribution network intelligent terminal battery isolation monitoring device - Google Patents

Abstract

The invention discloses a battery isolation monitoring device for an intelligent terminal of an active distribution network, which includes a self-excitation synchronous signal circuit and a synchronous signal output circuit, and is characterized in that: the signal input protection circuit is connected with a push-pull circuit wire, and the push-pull The pull circuit is connected with the signal output protection circuit, the signal output protection circuit is connected with the AD module, the self-excitation synchronous signal circuit and the synchronous signal output circuit are connected with the push-pull circuit wire; There are technical problems such as low precision, high cost, and poor anti-interference and surge anti-interference in the status monitoring of the storage battery of the intelligent terminal.

Description

A battery isolation monitoring device for intelligent terminal of active distribution network

technical field

The invention belongs to the battery monitoring technology of an intelligent terminal of a power grid, and in particular relates to a battery isolation monitoring device for an intelligent terminal of an active power distribution network.

Background technique:

The battery in the intelligent terminal equipment of the active distribution network is used as a backup power supply, and it is responsible for supplying power to the terminal and providing power to the operating switch during a power outage. For the reliability of the power grid, it is necessary to monitor the state of the storage battery of the intelligent terminal of the active distribution network.

Traditional power distribution terminal battery device monitoring schemes include the following: voltage-frequency conversion scheme, the voltage signal is converted into a frequency signal by a voltage-frequency conversion chip, and the frequency signal is transmitted to the CPU for sampling through high-speed optocoupler isolation. The main disadvantage of this device solution is that the sampling accuracy is low (the accuracy of voltage conversion into frequency is limited), and at the same time, because the continuous counting of frequency signals takes up more CPU resources, the cost is higher; the AD sampling of an independent CPU is adopted, and the isolation communication The scheme of serial port transmission to the main CPU. This device scheme also has some shortcomings. The front-end sampling CPU is susceptible to interference, and it is difficult to meet the EMC test requirements such as fast transient anti-interference and surge anti-interference on the basis of adding a large number of protection circuits. Communication occupies one serial interface of the main CPU, which makes it difficult to configure hardware resources for the intelligent terminal of the active distribution network that originally needs multiple serial ports, and also causes high cost of peripheral circuits.

Invention content:

The technical problem to be solved by the present invention is to provide a battery isolation monitoring device for intelligent terminal of active distribution network to solve the problem of low accuracy and high cost in the state monitoring of the storage battery of intelligent terminal of active distribution network in the prior art , fast transient anti-interference and poor surge anti-interference and other technical problems.

Technical scheme of the present invention:

A battery isolation monitoring device for intelligent terminals in active distribution networks, which includes a self-excitation synchronous signal circuit and a synchronous signal output circuit, the signal input protection circuit is connected to the push-pull circuit wire, and the push-pull circuit is connected to the signal output protection circuit Guide connection, the signal output protection circuit is connected with the AD module guide, the self-excitation synchronous signal circuit and the synchronous signal output circuit are connected with the push-pull circuit wire.

The push-pull circuit includes a push-pull modulation circuit and a rectification demodulation circuit, and the push-pull modulation circuit and the rectification demodulation circuit are connected through an isolation transformer.

The self-excitation synchronous signal circuit and the synchronous signal output circuit are connected through an isolation transformer.

The signal input protection circuit includes a first-level protection circuit, the first-level protection circuit is connected with the wires of the second-level protection circuit, and the second-level protection circuit is connected with the wires of the third-level protection circuit. The first-level protection circuit includes a fuse F1 and a varistor RV1, and the fuse F1 and varistor RV1 are connected in series; the secondary protection circuit is a low-pass filter circuit composed of inductor L2 and capacitor C1; the tertiary protection circuit includes TVS transient suppression diode D1, capacitor C2 and capacitor CF1, TVS transient suppression diode D1 It is connected in parallel with capacitor C2, and capacitor CF1 is grounded.

The signal output protection circuit includes a TVS transient suppression diode D7, and the TVS transient suppression diode D7 is connected to a resistor R7, and the resistor R7 is connected to a wire of the Schottky diode V1.

Beneficial effects of the present invention:

In the present invention, the input signal first passes through the protection circuit, then passes through the push-pull circuit, and then is transmitted through the isolation transformer. The rectification modulation circuit, and then controlled by the synchronous signal output circuit to complete the rectification output, and finally through the signal protection circuit at the output end, and finally the signal output is sent to the AD of the main CPU for sampling;

The invention adopts the isolation transformer to convert the signal, which is simpler than the scheme of directly AD sampling signal and then isolated and transmitted to protect the circuit, and the protection of the coil at the input end is easier than the protection of the input pin of the chip;

The present invention directly uses the voltage of the storage battery as the oscillation transmission of the self-excitation signal control circuit, and the integrated solution saves an isolated power supply module;

The present invention adopts the transformer isolator to convert the signal. For a single coil that has been made, the transformation ratio is a stable parameter, which ensures the linearity of sampling and has better accuracy than the voltage-frequency scheme; at the same time, the primary and secondary sides of the coil There is a transformation ratio, which saves the step-down circuit at the output end;

Compared with the traditional scheme device, the present invention does not need to occupy the communication port, and reduces the hardware resource requirement of the CPU;

Compared with the traditional solution device, the present invention does not need the continuous interrupt counting of the CPU and saves the CPU processor occupancy rate, so that a high-performance and low-cost solution can be realized;

The present invention uses an isolation transformer as the signal transmission isolation realization carrier, the DC signal is transmitted through the isolation transformer through the modulation circuit, and the secondary side of the transformer demodulates the signal, and at the same time, the power supply of the storage battery is used as the synchronous signal excitation source for signal transmission, through the input signal terminal The protection circuit is added to the secondary side of the transformer to meet the anti-interference requirements of surge and fast transient tests; it solves the problems of low precision, high cost and fast transient in the state monitoring of the storage battery of the intelligent terminal of the active distribution network in the existing technology. Technical problems such as poor anti-interference and surge anti-interference.

Description of drawings:

Fig. 1 is a block diagram of the overall architecture of the present invention;

Fig. 2 is a schematic diagram of an input signal protection circuit;

Fig. 3 is a schematic diagram of an output signal protection circuit;

Fig. 4 is a schematic diagram of a push-pull circuit;

FIG. 5 is a schematic diagram of the overall circuit structure of the present invention.

detailed description:

A battery isolation monitoring device for intelligent terminals in active distribution networks (see Figure 1), which includes a self-excitation synchronous signal circuit and a synchronous signal output circuit, the signal input protection circuit is connected to the push-pull circuit wire, and the push-pull circuit It is connected with the signal output protection circuit in a guided manner, the signal output protection circuit is connected with the AD module in a guided manner, and the self-excitation synchronous signal circuit and the synchronous signal output circuit are connected with the push-pull circuit wire.

The push-pull circuit includes a push-pull modulation circuit and a rectification demodulation circuit, and the push-pull modulation circuit and the rectification demodulation circuit are connected through an isolation transformer.

The self-excitation synchronous signal circuit and the synchronous signal output circuit are connected through an isolation transformer.

The signal input protection circuit (see Figure 2) includes a first-level protection circuit, the first-level protection circuit is connected with the wires of the second-level protection circuit, and the second-level protection circuit is connected with the wires of the third-level protection circuit. The first-level protection circuit includes a fuse F1 and a voltage Sensitive resistor RV1, fuse F1 and varistor RV1 are connected in series; the secondary protection circuit is a low-pass filter circuit composed of inductor L2 and capacitor C1; the tertiary protection circuit includes TVS transient suppression diode D1, capacitor C2 and capacitor CF1, TVS TVS diode D1 and capacitor C2 are connected in parallel, and capacitor CF1 is grounded.

The fuse F1 mainly protects the short circuit of the rear stage, especially when the short circuit of the rear stage of the battery is very dangerous. The varistor RV1 performs a primary filter on the lightning surge signal, and the failure model of the varistor is a short circuit, so the fuse F1 is also particularly important; The low-pass filter circuit composed of L2 and C1 further filters high-frequency signals. The three-level protection circuit uses the TVS transient suppression diode D1 to further filter and clamp the surge differential mode interference signal; at the same time, the capacitor CF1 filters the common mode signal to the ground to eliminate the interference signal.

The signal output protection circuit (see Figure 3) includes TVS transient suppression diode D7, TVS transient suppression diode D7 is connected to resistor R7, and resistor R7 is connected to Schottky diode V1 wire.

TVS transient suppression diode D7 suppresses the coupled high voltage, R7 limits the current, and V1 clamps the input voltage so that the signal voltage input to AD is controlled within the sampling input tolerance range.

Fig. 4 is a schematic diagram of a push-pull circuit structure,

R1, R2, R3, R4, R5, R6 are resistors, Q1, Q2, Q3, Q4 are transistors, and L1 is a transformer.

R1 is connected to the base of the transistor Q1, the collector of Q1 is connected to the same-named end wire of the primary tap N1 of the transformer L1, and the emitter of Q1 is connected to the emitter wire of Q2. R2 is connected to the base of the transistor Q2, the collector of Q2 is connected to the non-identical end wire of the tap N2 of the primary side of the transformer L1, and the emitter of Q2 is connected to the emitter wire of Q1. R5 is connected to the base of the triode Q3, the collector of Q3 is connected to the wire of the same name end of the tap S1 of the secondary side of the transformer L1, and the emitter of Q3 is connected to the emitter of Q4.

R6 is connected to the base of the transistor Q4, the collector of Q4 is connected to the non-identical terminal wire of the tap S2 of the secondary side of the transformer L1, and the emitter of Q3 is connected to the emitter wire of Q4.

Resistors R3 and R4 are connected in the middle of the voltage divider to the middle taps of N3 and N4 on the primary side of the transformer L1, the same-named end of N3 is connected to the wire of resistor R2, and the non-identical end of N4 is connected to the wire of resistor R1. The middle taps of S3 and S4 on the secondary side of L1 are connected to Vo-, the same-named end of S3 is connected to resistor R6, and the non-identical end of S4 is connected to resistor R5.

The input voltage signal is modulated into a square wave through the alternation of Q1 and Q2 transistors, and then coupled and transmitted through the transformer. The square wave signal on the secondary side of the transformer is rectified under the control of the synchronous signal through Q3 and Q4 transistors, and finally modulated into a The DC signal is sent to the sampling terminal. When the battery voltage is applied to Vi, the triode Q1 and Q2 are both forward biased through the resistor R3 and tend to be turned on. However, since the characteristics of the two triodes are not completely consistent, there must be a larger circuit through which the triode flows. Priority conduction.

At the same time, the transistor that is preferentially turned on will inhibit the conduction of the other transistor. After the turned-on triode is amplified to saturation and then amplified to cut-off, it will trigger the conduction of another triode. This process is repeated continuously to form a shock.

Claims (5)

1. one kind is used for active power distribution network intelligent terminal battery isolation monitoring device, it is including autoexcitation synchronous signal circuit and together Walk signal output apparatus, it is characterised in that：Signal input protection circuit is connected with push-pull circuit wire, push-pull circuit and letter Number output protection circuit is oriented to connection, and signal output protection circuit is oriented to A/D module and connected, autoexcitation synchronous signal circuit and Synchronizing signal output circuit is connected with push-pull circuit wire.

2. a kind of active power distribution network intelligent terminal battery that is used for according to claim 1 isolates monitoring device, its feature exists In：The push-pull circuit includes recommending modulation circuit and rectification demodulator circuit, recommends modulation circuit and rectification demodulator circuit leads to Cross isolating transformer connection.

3. a kind of active power distribution network intelligent terminal battery that is used for according to claim 1 isolates monitoring device, its feature exists In：Autoexcitation synchronous signal circuit is connected with synchronizing signal output circuit by isolating transformer.

4. a kind of active power distribution network intelligent terminal battery that is used for according to claim 1 isolates monitoring device, its feature exists In：Signal input protection circuit includes first class of protection circuit, and first class of protection circuit is connected with safe secondary protection circuit wire, and two level is protected Protection circuit is connected with three-level protective circuit lead, and the first class of protection circuit includes fuse F1 and piezo-resistance RV1, fuse F1 and piezo-resistance RV1 are connected in series；Safe secondary protection circuit is the low-pass filter circuit that inductance L2 and electric capacity C1 is formed；Three-level is protected Protection circuit includes TVS Transient Suppression Diodes D1, electric capacity C2 and electric capacity CF1, TVS Transient Suppression Diode D1 and electric capacity C2 are in parallel Connection, electric capacity CF1 ground connection.

5. a kind of active power distribution network intelligent terminal battery that is used for according to claim 1 isolates monitoring device, its feature exists In：Signal output protection circuit is connected including TVS Transient Suppression Diodes D7, TVS Transient Suppression Diode D7 with resistance R7, Resistance R7 is connected with Schottky diode V1 wires.