阅读说明：本技术 一种用于无源二次回路的三相程控测试电源电路 (Three-phase program-controlled test power supply circuit for passive secondary circuit ) 是由 张伍 杨盛德 郑丹丹 于 2020-12-15 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的三相程控测试电源电路,包括输出变压器电路、输出电参量检测电路、数字功放电路、D/A转换电路、主控MCU电路、无线通信电路、锂电池供电管理电路、保护电路和人机交互电路,输出变压器电路包括输出变压器和三个限流电阻,输出变压器电路的三相输入信号UA、UB和UC均与数字功放电路的输出端电性连接。本发明在母线不带电状态下对计量回路一二次侧回路进行接线检查,要求三相测试程控源自带电池组,能够输出三相带相位的可调电压,电流信号,并有足够幅度和功率满足后级检测要求,具有小型化、便携化、方便收纳和现场操作的优点。(The invention discloses a three-phase program-controlled test power supply circuit for a passive secondary circuit, which comprises an output transformer circuit, an output electric parameter detection circuit, a digital power amplifier circuit, a D/A conversion circuit, a master control MCU circuit, a wireless communication circuit, a lithium battery power supply management circuit, a protection circuit and a man-machine interaction circuit, wherein the output transformer circuit comprises an output transformer and three current-limiting resistors, and three-phase input signals UA, UB and UC of the output transformer circuit are all electrically connected with the output end of the digital power amplifier circuit. The invention carries out wiring check on the primary and secondary side loops of the metering loop under the condition that the bus is not electrified, requires that the three-phase test program is derived from the self-contained battery pack, can output three-phase adjustable voltage and current signals with phases, has enough amplitude and power to meet the requirements of later-stage detection, and has the advantages of miniaturization, portability, convenient storage and field operation.)

1. A three-phase program-controlled test power supply circuit for a passive secondary loop comprises an output transformer circuit (1), an output electric parameter detection circuit (2), a digital power amplifier circuit (3), a D/A conversion circuit (4), a main control MCU circuit (5), a wireless communication circuit (6), a lithium battery power supply management circuit (7), a protection circuit (8) and a man-machine interaction circuit (9), and is characterized in that the output transformer circuit (1) comprises an output transformer (101) and three current-limiting resistors (102), three-phase input signals UA, UB and UC of the output transformer circuit (1) are electrically connected with the output end of the digital power amplifier circuit (3), the output signals UA/Ia, UB/Ib, UC/Ic, Ia0, 36Ib, Ic0 and UN signal ends of the output transformer circuit (1) are respectively electrically connected with a unit voltage current output line of the man-machine interaction circuit (9), the output circuits UA/Ia, UB/Ib, UC/Ic and UN of the output transformer (101) and signals Ia0, Ia-, Ib0, Ib-, Ic0 and Ic-at two ends of the current-limiting resistor are respectively and electrically connected to the voltage and current input end of the output parameter detection circuit (2);

input driving signals UAAC, UBAC and UCAC of the digital power amplifier circuit (3) are respectively and electrically connected to a D/A output end of the D/A conversion circuit (4), and overload overcurrent protection signals UABJ _ IN, UBBJ _ IN and UCBJ _ IN of the digital power amplifier circuit (3) are respectively and electrically connected to the protection circuit (8);

the serial SPI control buses JL-CS, JL-CLK, JL-SDO, JL-SDI and JL-RST of the master MCU circuit (5) are respectively and electrically connected to the output electric parameter detection circuit (2), the digital interfaces D0, D1, D2, D3, D4, D5, D6, D7, D8, D9, D10, D11, D12, D13, D14, D15, A0 and A1 of the master MCU circuit (5) are respectively and electrically connected to the D/A conversion circuit (4), the serial ports U2RX and U2TX of the master MCU circuit (5) are respectively and electrically connected to the wireless communication circuit (6), the serial ports STOLOAD, SPI _ CLK, CS _165 and SPI _ R of the master MCU circuit (5) are respectively and electrically connected to the SPI _ CLK, SPI _595, the serial ports of the master control MCU circuit (5) are respectively and the SPI _ CLK and the serial port-595 are electrically connected to the man-machine circuit (8), the master control MCU circuit (5) is electrically connected with the lithium battery power supply management circuit (7).

2. The three-phase programmable test power supply circuit for the passive secondary circuit is characterized in that a first group of coils on the secondary side of a transformer of the output transformer circuit (1) are connected with different-name ends through UN to form a star connection to form a three-phase four-wire power supply, and a second group of coils of the transformer are connected with a load circuit CT through a current limiting resistor to form three independent current loops.

3. The three-phase programmable test power supply circuit for the passive secondary circuit is characterized in that the output electric parameter detection circuit (2) comprises an electric energy metering unit, a voltage sampling unit, a current sampling unit and an electric energy metering chip, and the output voltage effective value, the current effective value, the frequency value, the phase value, the power value and the electric energy value of the three-phase source are accurately calculated through real-time sampling of output voltage and current.

4. The three-phase programmable test power supply circuit for the passive secondary circuit according to claim 1, wherein the digital power amplifier circuit (3) is composed of an input proportional amplifier circuit, a digital power amplifier chip circuit and an output filter circuit, wherein the digital power amplifier chip internally comprises a signal conditioning, PWM modulation, driving and H-bridge conversion circuit, so as to amplify the power of the D/A conversion signal and drive the output transformer to drive the three-phase test source load.

5. The three-phase programmable test power supply circuit for the passive secondary circuit according to claim 1, characterized in that the D/A conversion circuit (4) comprises a parallel port data input interface, a D/A conversion chip and an output buffer amplifier.

6. The three-phase program-controlled test power supply circuit for the passive secondary circuit according to claim 1, characterized in that the main control MCU circuit (5) adopts STM32F407-ZGT main control CPU to complete the functions of waveform synthesis, D/A digital-to-analog circuit control, output electrical parameter detection circuit control, data processing, undervoltage detection, overload and overcurrent protection circuit control, wireless communication command analysis, command processing, power supply control and man-machine interaction control.

7. The three-phase programmable test power supply circuit for the passive secondary circuit according to claim 1, wherein the wireless communication module of the wireless communication circuit (6) is completed by a bluetooth HC-05 module through a UART serial port.

8. The three-phase programmable test power supply circuit for the passive secondary circuit is characterized in that a lithium battery power supply management (7) circuit comprises a lithium battery charge and discharge management chip IP5328P, a lithium battery protection circuit, a lithium battery, a TYPE-C interface circuit and a DCDC circuit, and mainly completes charge and discharge management, lithium battery under-voltage protection and over-current protection of the lithium battery to provide power supply energy for other circuits of the whole machine, wherein +5V and 3.3V are power supplies, and BAT + and BAT-are positive and negative electrodes of the lithium battery.

9. The three-phase programmable test power supply circuit for the passive secondary circuit according to claim 1, characterized in that the protection circuit (8) is composed of a protection chip circuit, and receives the overload and overcurrent alarm signals of the digital power amplifier in real time.

10. The three-phase programmable test power supply circuit for the passive secondary circuit according to claim 1, characterized in that the human-computer interaction circuit (9) mainly comprises three-phase voltage and current output terminals, three-phase power supply output keys and three-phase power supply output indication.

Technical Field

The invention relates to the technical field of electrical measurement, in particular to a three-phase program-controlled test power supply circuit for a passive secondary circuit.

Background

At present, PT, CT, electric energy meters, acquisition terminals and a combined junction box are installed in high-voltage and low-voltage metering cabinets, which are conventional work of high-voltage and low-voltage electric energy metering installation business, but the installation and debugging working mode of the existing user side metering cabinet, particularly the metering secondary circuit of a medium-low voltage user of 10KV and below, is relatively lagged; after the assembly operation is completed, a user is usually in a no-load and no-power-off state, so that whether the installation of the metering loop is correct or not cannot be judged, and the metering secondary loop is connected incorrectly due to human factors and irregular operation, so that unnecessary loss and dispute are caused to a power grid and customers.

The existing three-phase programmable power supply in the market at present is generally large in size, heavy, high in cost and complex in operation, does not have an internal battery pack, cannot work under the condition of no external power supply.

Disclosure of Invention

The present invention is directed to a three-phase programmable test power circuit for a passive secondary circuit, so as to solve the problems mentioned in the background art.

In order to achieve the purpose, the invention provides the following technical scheme: a three-phase program-controlled test power supply circuit for a passive secondary loop comprises an output transformer circuit, an output electric parameter detection circuit, a digital power amplifier circuit, a D/A conversion circuit, a main control MCU circuit, a wireless communication circuit, a lithium battery power supply management circuit, a protection circuit and a man-machine interaction circuit, wherein the output transformer circuit comprises an output transformer and three current-limiting resistors, three-phase input signals UA, UB and UC of the output transformer circuit are electrically connected with the output end of the digital power amplifier circuit, the output circuits UA/Ia, UB/Ib, UC/Ic, Ia0, Ib0, Ic0 and UN signal ends of the output transformer circuit are respectively electrically connected with a unit voltage and current output line of the man-machine interaction circuit, and the output circuits UA/Ia, UB/Ib, UC/Ic and UN of the output transformer and two ends of the current-limiting resistors are electrically connected with Ia0, The Ia-, Ib-0, Ib-, Ic0 and Ic-signals are respectively and electrically connected to the voltage and current input end of the output electrical parameter detection circuit;

the digital power amplifier circuit comprises a digital power amplifier circuit, a protection circuit and a digital/analog conversion circuit, wherein input driving signals UAAC, UBAC and UCAC of the digital power amplifier circuit are respectively and electrically connected to the D/A output end of the D/A conversion circuit, and overload overcurrent protection signals UABJ _ IN, UBBJ _ IN and UCBJ _ IN of the digital power amplifier circuit are respectively and electrically connected to the protection circuit;

the serial SPI control buses JL-CS, JL-CLK, JL-SDO, JL-SDI and JL-RST of the main control MCU circuit are respectively and electrically connected with the output electric parameter detection circuit, the digital interfaces D0, D1, D2, D3, D4, D5, D6, D7, D8, D9, D10, D11, D12, D13, D14, D15, A0 and A1 of the master control MCU circuit are respectively and electrically connected with the D/A conversion circuit, the UART serial ports U2RX and U2TX of the master control MCU circuit are respectively and electrically connected with the wireless communication circuit, the serial SPI interface LOAD, SPI _ CLK, CS _165 and SPI _ R signals of the master control MCU circuit are electrically connected to the protection circuit, the serial SPI and IO input SPI _ TX, SPI _ CLK, CS _595 and RUN-STOP signals of the main control MCU circuit are electrically connected to the man-machine interaction circuit, and the main control MCU circuit is electrically connected with the lithium battery power supply management circuit;

preferably, the first group of coils on the secondary side of the transformer of the output transformer circuit connects the different-name ends together through UN to form a star connection to form a three-phase four-wire power supply, and the second group of coils of the transformer is connected with a load circuit CT through a current-limiting resistor to form three independent current loops.

Preferably, the output electrical parameter detection circuit comprises an electrical energy metering unit, a voltage sampling unit, a current sampling unit and an electrical energy metering chip, and the output voltage effective value, the current effective value, the frequency value, the phase value, the power value and the electrical energy value of the three-phase source are accurately calculated by sampling the output voltage and the output current in real time.

Preferably, the digital power discharge circuit is composed of an input proportion amplifying circuit, a digital power amplifier chip circuit and an output filter circuit, wherein the digital power amplifier chip internally comprises a signal conditioning circuit, a PWM (pulse width modulation) circuit, a driving circuit and an H-bridge conversion circuit, the power amplification of the D/A conversion signal is completed, and the output voltage transformation is driven to drive the three-phase test source load.

Preferably, the D/a conversion circuit includes a parallel port data input interface, a D/a conversion chip, and an output buffer amplifier.

Preferably, the main control MCU circuit adopts STM32F407-ZGT main control CPU to complete the functions of waveform synthesis, D/A digital-analog circuit control, output electric parameter detection circuit control, data processing, undervoltage detection, overload and overcurrent protection circuit control, wireless communication command analysis, command processing, power supply control and man-machine interaction control.

Preferably, the wireless communication module of the wireless communication circuit is completed by a bluetooth HC-05 module through UART serial port transmission.

Preferably, the lithium battery power supply management circuit comprises a lithium battery charge and discharge management chip IP5328P, a lithium battery protection circuit, a lithium battery, a TYPE-C interface circuit and a DCDC circuit, and is mainly used for completing charge and discharge management, lithium battery under-voltage protection and over-current protection of the lithium battery and providing power supply energy for other circuits of the whole machine, wherein +5V and 3.3V are power supply sources, and BAT + and BAT-are positive and negative electrodes of the lithium battery.

Preferably, the protection circuit is composed of a protection chip circuit and receives overload and overcurrent alarm signals of the digital power amplifier in real time.

Preferably, the human-computer interaction circuit mainly comprises a three-phase voltage and current output terminal, a three-phase power supply output key and a three-phase power supply output indication.

The invention has the technical effects and advantages that:

the wiring inspection is carried out to a primary and secondary side loop of the metering loop under the condition that a bus is not electrified, the three-phase test program control is required to be sourced from an electrified battery pack, the adjustable voltage and current signals of three-phase electrified phases can be output, enough amplitude and power meet the requirement of rear-stage detection, and the portable metering device has the advantages of being small in size, portable, convenient to store and operate on site.

Drawings

Fig. 1 is a schematic block diagram of a three-phase programmable test power supply of a high-voltage metering circuit of the invention.

Fig. 2 is a circuit diagram of an output transformer circuit according to the present invention.

FIG. 3 is a circuit diagram of a current collecting channel between an output transformer circuit and an output electrical parameter detecting circuit according to the present invention.

Fig. 4 is a circuit diagram of the connection of three-phase input signals UA, UB and UC and the digital power amplifier circuit according to the present invention.

FIG. 5 is a circuit diagram of the digital power amplifier circuit of the present invention with input driving signals UAAC, UBAC and UCAC respectively connected to the D/A conversion circuit.

FIG. 6 is a circuit diagram of the digital interface signal of the D/A conversion circuit of the present invention connected to the main control MCU circuit.

FIG. 7 is a circuit diagram of a UART serial port U2RX and U2TX wireless communication circuit of the master MCU circuit of the present invention.

Fig. 8 is a circuit diagram of a lithium battery power supply management circuit according to the present invention.

Fig. 9 is a circuit diagram of the overload and overcurrent protection circuit of the three-phase power supply of the invention.

Fig. 10 is a circuit diagram of a three-phase power output circuit according to the present invention.

In the figure: 1. an output transformer circuit; 101. an output transformer; 102. a current limiting resistor; 2. an output electrical parameter detection circuit; 3. a digital power amplifier circuit; 4. a D/A conversion circuit; 5. a master control MCU circuit; 6. a wireless communication circuit; 7. a lithium battery power supply management circuit; 8. a protection circuit; 9. and a man-machine interaction circuit.

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 present invention provides a three-phase programmable test power supply circuit for a passive secondary circuit as shown in figures 1-10,

the first embodiment is as follows:

the power supply protection circuit comprises an output transformer circuit 1, an output electric parameter detection circuit 2, a digital power amplifier circuit 3, a D/A conversion circuit 4, a main control MCU circuit 5, a wireless communication circuit 6, a lithium battery power supply management circuit 7, a protection circuit 8 and a man-machine interaction circuit 9, wherein the output transformer circuit 1 comprises an output transformer 101 and three current-limiting resistors 102;

three-phase input signals UA, UB and UC of the output transformer circuit 1 are electrically connected with the output end of the digital power amplifier circuit 3, signal ends UA/Ia, UB/Ib, UC/Ic, Ia0, Ib0, Ic0 and UN of the output transformer circuit 1 are respectively and electrically connected with a unit voltage and current output line of the man-machine interaction circuit 9, and output signals UA/Ia, UB/Ib, UC/Ic and UN of the output transformer 101 and current-limiting resistor two ends Ia0, Ia-, 0, Ib-, Ic0 and Ic-are respectively and electrically connected to a voltage and current input end of the output parameter detection circuit 2;

the input driving signals UAAC, UBAC and UCAC of the digital power amplifier circuit 3 are respectively and electrically connected to the D/A output end of the D/A conversion circuit 4, and the overload overcurrent protection signals UABJ _ IN, UBBJ _ IN and UCBJ _ IN of the digital power amplifier circuit 3 are respectively and electrically connected to the protection circuit 8;

the serial SPI control buses JL-CS, JL-CLK, JL-SDO, JL-SDI and JL-RST of the main control MCU circuit 5 are respectively and electrically connected to the output electrical parameter detection circuit 2, digital interfaces D0, D1, D2, D3, D4, D5, D6, D7, D8, D9, D10, D11, D12, D13, D14, D15, A0 and A1 of the main control MCU circuit 5 are respectively and electrically connected to the D/A conversion circuit 4, UART serial ports U2RX and U2TX of the main control MCU circuit 5 are respectively and electrically connected to the wireless communication circuit 6, serial SPI interfaces LOAD, SPI _ CLK, CS _165 and SPI _ R of the main control MCU circuit 5 are electrically connected to the protection circuit 8, serial SPI and IO input SPI _ TX, SPI _ CLK, CS _595 and RUN-STOP of the main control MCU circuit 5 are electrically connected to the man-machine interaction circuit 9, and the main control MCU circuit 5 is electrically connected to the lithium battery power supply management circuit 7.

Example two:

the connection relationship and the principle between the modules are described as follows:

s1: output transformer circuit

As shown in fig. 2, the output transformer circuit includes a three-phase four-wire voltage source output formed by a first set of coils on the secondary side of the transformer (the first set of coils on the secondary side of the transformer connect different-name terminals together through UN to form a star connection to form a three-phase four-wire power supply), and a second set of coils on the secondary side of the transformer convert voltage signals into current signals through a current limiting resistor to form three independent current source outputs (the second set of coils on the secondary side of the transformer are connected with a load circuit CT through a current limiting resistor to form three independent current loops, which refer to a load part shown in fig. 1);

wherein, the three-phase input signals UA, UB and UC are connected with the digital power amplifier circuit part and refer to FIG. 4;

s2: output electric parameter detection circuit

The output electric parameter detection circuit comprises an electric energy metering unit, a voltage sampling unit, a current sampling unit and an electric energy metering chip, and accurately calculates an output voltage effective value, a current effective value, a frequency value, a phase value, a power value and an electric energy value of a three-phase source through real-time sampling of output voltage and current, so that the output precision and stability of the three-phase power supply are improved;

the voltage current inputs UA/Ia, UB/Ib, UC/Ic, UN, Ia0, Ia-, Ib0, Ib-, Ic0 and Ic-are respectively connected to the output ends of the output transformers with reference to FIG. 2;

serial SPI control buses JL-CS, JL-CLK, JL-SDO, JL-SDI, and JL-RST are respectively connected to the master control MCU circuit, referring to fig. 6;

s3: digital power amplifier

The digital power amplifier chip internally comprises a signal conditioning circuit, a PWM (pulse width modulation) modulation circuit, a driving circuit and an H-bridge conversion circuit, and has the functions of amplifying the power of a D/A (digital/analog) conversion signal and driving an output voltage transformation to drive a three-phase test source load;

the output signals UA, UB and UC are respectively connected with the output transformer circuit with reference to FIG. 2;

the input driving signals UAAC, UBAC and UCAC are respectively connected with a D/A conversion circuit, refer to FIG. 5;

overload overcurrent protection signals UABJ _ IN, UBBJ _ IN and UCBJ _ IN are respectively connected with a protection circuit reference figure 9;

s4: D/A conversion circuit

The D/A conversion circuit comprises a parallel port data input interface, a D/A conversion chip and an output buffer amplifier;

D/A output signals UAAC, UBAC and UCAC are respectively connected with a digital power amplifier circuit reference such as 4;

the digital interfaces D0, D1, D2, D3, D4, D5, D6, D7, D8, D9, D10, D11, D12, D13, D14, D15, a0 and a1 are respectively connected with the master MCU circuit, refer to fig. 6;

s5: master control MCU circuit

The main control MCU circuit adopts an STM32F407-ZGT main control CPU, and the main functions of the main control MCU circuit are waveform synthesis, D/A digital-to-analog circuit control, output electric parameter detection circuit control, data processing, under-voltage detection, overload and overcurrent protection circuit control, wireless communication command analysis, command processing, power supply control and human-computer interaction control;

the serial SPI control buses JL-CS, JL-CLK, JL-SDO, JL-SDI and JL-RST are respectively connected with an output electric parameter detection circuit, and the reference is made to the graph 3;

the digital interfaces D0, D1, D2, D3, D4, D5, D6, D7, D8, D9, D10, D11, D12, D13, D14, D15, a0 and a1 are respectively connected with the D/a conversion circuit, refer to fig. 5;

UART serial port U2RX, U2TX signal wireless communication circuit refer to FIG. 7 respectively;

the serial SPI interface LOAD, SPI _ CLK, CS _165 and SPI _ R signals are connected with the protection circuit, and the reference figure 9 is shown;

serial SPI and IO inputs SPI _ TX, SPI _ CLK, CS _595, RUN-STOP signals to the human-computer interaction circuit refer to fig. 10;

s6: wireless communication circuit

The wireless communication module is provided with a Bluetooth HC-05 module which is completed by transparent transmission through a UART serial port;

signals of the UART serial ports U2RX and U2TX are respectively connected with the master control MCU circuit, referring to the figure 6;

s7: lithium battery power supply management circuit

The lithium battery power supply management circuit comprises a lithium battery charge and discharge management chip IP5328P, a lithium battery protection circuit, a lithium battery, a TYPE-C interface circuit and a DCDC circuit (+ 5V to 3.3V), mainly completes charge and discharge management, lithium battery under-voltage and over-current protection and provides power supply energy for other circuits of the whole machine, wherein +5V and 3.3V are power supply sources, and BAT + and BAT-are positive and negative electrodes of the lithium battery;

s8: protective circuit

The three-phase power supply is overloaded, and an overcurrent protection circuit is formed by a protection chip circuit as shown in fig. 9 and receives overload and overcurrent alarm signals of the digital power amplifier in real time;

wherein, UABJ _ IN, UBBJ _ IN and UCBJ _ IN alarm input signals are connected to the digital power amplifier circuit and refer to FIG. 4;

serial SPI interface LOAD, SPI _ CLK, CS _165, SPI _ R signal receiving Master MCU Circuit with reference to FIG. 6

S9: man-machine interaction circuit

The man-machine interaction circuit mainly comprises a three-phase voltage and current output terminal, a three-phase power supply output key start/stop button and a three-phase power supply output instruction, and has the main functions of facilitating the operation and control of a user, indicating the power supply state and connecting a voltage and current wire harness;

the input/output signals UA/Ia, UB/Ib, UC/Ic, Ia0, Ib0, Ic0 and UN are respectively connected with the output transformer and the load of the three-phase metering loop, which is shown in the reference figures 1 and 2;

the serial SPI and IO inputs SPI _ TX, SPI _ CLK, CS _595 and RUN-STOP signals are connected to the master MCU circuit respectively as shown with reference to fig. 6.

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.