阅读说明：本技术 一种用于无源二次回路检查源的电压电流输出电路 (Voltage and current output circuit for passive secondary loop inspection source ) 是由 张伍 杨盛德 白福庆 于 2020-07-03 设计创作，主要内容包括：本发明公开了一种用于无源二次回路检查源的电压电流输出电路,包括输入单元、变压器单元和输出单元,该电路将三路输入信号转化为三相四线制电压输出和三相电流输出,输入和输出电路支持多种接线方式,给二次计量回路的PT和CT提供测试电源,输入单元电路由A相输入、B相输入、C相输入和六个端子组成,变压器单元一次侧有三组输入用于三相功率信号的输入,二次侧有三相四线电压组和三相大电流输出组用于驱动后级测试PT和CT,三相大电流输出组通过限流电阻将输出电压转化为电流信号。本发明将三路输入信号转化为三相四线制电压输出和三相电流输出,输入和输出电路支持多种接线方式,原理简单,功能强大,非常适合给二次计量回路的PT,CT提供测试电源。(The invention discloses a voltage and current output circuit for a passive secondary circuit inspection source, which comprises an input unit, a transformer unit and an output unit, wherein the circuit converts three paths of input signals into three-phase four-wire system voltage output and three-phase current output, the input and output circuits support various wiring modes and provide a test power supply for PT and CT of a secondary metering circuit, the input unit circuit consists of an A-phase input, a B-phase input, a C-phase input and six terminals, three groups of inputs are arranged on the primary side of the transformer unit and used for inputting three-phase power signals, a three-phase four-wire voltage group and a three-phase heavy current output group are arranged on the secondary side of the transformer unit and used for driving the PT and CT to be tested at the later stage, and the three-phase heavy current output group converts output voltage. The invention converts three-way input signals into three-phase four-wire system voltage output and three-phase current output, the input and output circuits support various wiring modes, the principle is simple, the function is strong, and the invention is very suitable for providing test power supply for PT and CT of a secondary metering loop.)

1. A voltage and current output circuit for a passive secondary circuit inspection source comprises an input unit (1), a transformer unit (2) and an output unit (3), wherein the circuit converts three-way input signals into three-phase four-wire system voltage output and three-phase current output, and the input and output circuit supports multiple wiring modes and provides a test power supply for PT and CT of a secondary metering circuit.

2. The voltage-current output circuit for the passive secondary loop check source according to claim 1, wherein the input unit (1) circuit is composed of an A-phase input, a B-phase input, a C-phase input and six terminals, and the six terminals can adapt to a plurality of access modes, namely three independent power signal access, three-phase four-wire access and three-phase three-access.

3. The voltage-current output circuit for a passive secondary circuit inspection source according to claim 1, wherein the transformer unit (2) has three input sets on the primary side for three-phase power signals, and three-phase four-wire voltage sets and three-phase large-current output sets on the secondary side for driving the post-stage tests PT and CT, and the three-phase large-current output sets convert the output voltages into current signals through current-limiting resistors, convert the three-phase input power signals into three-phase four-wire output voltage signals and three-phase independent large-current signal outputs.

4. The voltage-current output circuit for passive secondary circuit inspection source as claimed in claim 1, wherein said output unit (3) circuit has three-phase four-wire system voltage output composed of terminals UA, UB, UC and U0, terminals Ia0, Ib0 and Ic0 constituting current output circuit, which is applied to detection of three-phase three PT, CT secondary circuit and detection of three-phase four PT, CT secondary circuit by combination of these seven terminals.

Technical Field

The invention relates to the field of voltage and current output circuits, in particular to a voltage and current output circuit for a passive secondary circuit inspection source.

Background

The voltage and current output circuits of the existing three-phase programmable power supply, the three-phase test source, the three-phase standard source and other power supplies in the current market generally adopt discrete transformers, the converters output the voltage and current respectively, the circuits are generally large in size and heavy, the output voltage is up to 220VRMS, the power consumption is large, the circuits cannot work without an external power supply, the cost is high, and potential safety hazards exist when the circuits are used for testing the power supply of a secondary circuit.

Disclosure of Invention

The present invention is directed to a voltage/current output circuit for a passive secondary circuit inspection source, which solves the above problems.

In order to achieve the purpose, the invention provides the following technical scheme: a voltage and current output circuit for a passive secondary circuit inspection source comprises an input unit, a transformer unit and an output unit, wherein three paths of input signals are converted into three-phase four-wire system voltage output and three-phase current output by the circuit, and the input and output circuit supports various wiring modes and provides a test power supply for PT and CT of a secondary metering circuit.

Preferably, the input unit circuit consists of an a-phase input, a B-phase input, a C-phase input and six terminals, and the six terminals can adapt to various access modes, namely three independent power signal access modes, a three-phase four-wire system access mode and a three-phase three-access mode;

preferably, the transformer unit has three sets of inputs on the primary side for inputting three-phase power signals, a three-phase four-wire voltage set and a three-phase heavy current output set on the secondary side for driving the post-stage test PT and CT, and the three-phase heavy current output set converts output voltage into current signals through a current-limiting resistor, and converts three-phase input power signals into three-phase four-wire output voltage signals and three-phase independent heavy current signals for outputting.

Preferably, the output unit circuit has a three-phase four-wire system voltage output formed by terminals UA, UB, UC and U, and a current output loop formed by terminals Ia, Ib and Ic, and is applied to detection of a three-phase three-PT and CT secondary loop and detection of a three-phase four-PT and CT secondary loop through combination of the seven terminals.

The invention has the technical effects and advantages that:

the three-way input signal is converted into a three-phase four-wire system voltage output and a three-phase current output, the input and output circuit supports various wiring modes, the principle is simple, the function is strong, the test power supply is very suitable for providing a test power supply for PT and CT of a secondary metering loop, the power consumption is low, the cost is low, and the potential safety hazard can be reduced when the test power supply is used for testing the secondary loop.

Drawings

Fig. 1 is a circuit diagram illustrating the operation principle of the present invention.

Fig. 2 is a circuit diagram of an exemplary three-phase four-input application of the present invention.

Fig. 3 is a circuit diagram of an exemplary three-phase three-input application of the present invention. .

In the figure: 1. an input unit; 2. a transformer unit; 3. and an output unit.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention provides a voltage and current output circuit for a passive secondary loop inspection source as shown in figures 1-3, which comprises an input unit 1, a transformer unit 2 and an output unit 3, the working principle refers to figure 1, the circuit has the advantages that three paths of input signals are converted into three-phase four-wire system voltage output and three-phase current output, the input and output circuits support various wiring modes, the principle is simple, the function is strong, and a test power supply is provided for PT and CT of a secondary metering loop;

as shown in fig. 1, the input unit 1 has a circuit composed of an a-phase input, a B-phase input, a C-phase input, and six terminals, and the six terminals can adapt to various access modes, such as: three independent power signal accesses, three-phase four-wire system accesses, three-phase three-wire system accesses, and input application refers to fig. 1, fig. 2, and fig. 3 as examples;

the principle of the transformer unit 2 is shown in fig. 1, the transformer unit has three groups of inputs (three groups of inputs refer to not only three input coils as shown in fig. 1, but also each group can be composed of a plurality of coils) on the primary side for inputting three-phase power signals, a three-phase four-wire voltage group (three groups of four-wire voltage refer to not only three voltage coils as shown in fig. 1, each group can also be composed of a plurality of coils) and a three-phase large current output group (three-phase large current output group refer to not only three current coils as shown in fig. 1, each group can also be composed of a plurality of coils) for driving the post-stage test PT and CT, the three-phase large current output group converts the output voltage into current signals through a current-limiting resistor, converts the three-phase input power signals into three-phase four-wire output voltage signals and three-phase independent large current signals, the portable solar water heater has the advantages of small volume, light weight, low cost, low power consumption and convenient carrying;

the output unit 3 is shown in fig. 1, the circuit is composed of UA, UB, UC and U0 terminals to form a three-phase four-wire system voltage output, and Ia0, Ib0 and Ic0 terminals to form a current output loop, and the combination of the seven terminals can be applied to the detection of a three-phase three PT and CT secondary loop and the detection of a three-phase four PT and CT secondary loop, and the typical output application refers to fig. 2 and fig. 3 for example;

the main technical indexes are as follows:

(1) three-phase UA, UB, UC voltage output scope: 0V to 36V effective value;

(2) three-phase Ia0, Ib0, Ic0 current output range: 0A to 10A effective value;

(3) the three-phase voltage and current output are compatible at the same time: a three-phase three PT, CT metering loop and a three-phase four PT, CT metering loop;

(4) the three groups of A, B, C phase input modes are as follows: three-phase three-access, three-phase four-access and independent access.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments or portions thereof without departing from the spirit and scope of the invention.