Voltage measurement device and method

Abstract

The present disclosure provides a voltage measurement device and method, the device includes a voltage sampling module, a power conversion module, a VREF reference voltage module, a control module and a TTL communication isolation module, the input ends of the voltage sampling module and the power conversion module are connected to the voltage to be measured, the output end of the voltage sampling module is connected to the control module, the output end of the power conversion module is connected to the VREF reference voltage module and the control module respectively, the output end of the VREF reference voltage module is connected to the voltage sampling module, and the output end of the control module is connected to the TTL communication isolation module. The voltage measurement device provided by the present disclosure is directly connected to the voltage to be measured to take power through the voltage sampling module, and the signal is isolated and transmitted after operation by the control module, which not only ensures that the voltage measurement device is small in size and reduces the space occupied, but also ensures the accuracy of voltage measurement, and the signal transmission after isolation solves the problem of common mode interference, further improving the accuracy of voltage measurement.

Description

Technical Field

[0001] The present disclosure relates to the technical field of voltage measurement, and in particular to a voltage measurement device and method. Background Art

[0002] There are two common types of voltage measurement methods on the market. The first type uses a voltage transformer for isolation and then connects a resistor in series to generate a sampling signal. Its characteristic is that although it can achieve voltage isolation, the general transformer is large in size and occupies a large space on the measuring equipment. The other type is to directly connect multiple resistors for voltage division to generate a sampling signal. Its characteristic is that it occupies a small space on the measuring equipment, but the signal cannot be isolated and the measurement accuracy cannot be guaranteed. Summary of the invention

[0003] The purpose of the present disclosure is to provide a voltage measurement device and method, which can solve one or more of the above-mentioned problems in the prior art.

[0004] According to one aspect of the present disclosure, a voltage measuring device is provided, including a voltage sampling module, a power conversion module, a VREF reference voltage module, a control module and a TTL communication isolation module, wherein the input ends of the voltage sampling module and the power conversion module are both connected to a voltage to be measured, the output end of the voltage sampling module is connected to the control module, the output end of the power conversion module is respectively connected to the VREF reference voltage module and the control module, the output end of the VREF reference voltage module is connected to the voltage sampling module, and the output end of the control module is connected to the TTL communication isolation module.

[0005] In some embodiments, the voltage sampling module includes three groups of series resistors, one end of the three groups of series resistors are respectively connected to the A phase, B phase and C phase of the voltage to be measured, and the other end is connected to the control module as three output ends.

[0006] In some embodiments, each set of series resistors includes five resistors.

[0007] In some embodiments, the power conversion module includes a half-wave rectifier circuit, a field effect transistor Q1 and a chip U4 with model LR7533. The half-wave rectifier circuit includes a diode D1, a diode D2 and a diode D3. The positive poles of the diodes D1, D2 and D3 are respectively connected to the A phase, B phase and C phase of the voltage to be measured. The negative poles of the diodes D1, D2 and D3 are connected together and then connected to the positive pole of the diode D4. The negative pole of the diode D4 is connected to the drain of the field effect transistor Q1 through a resistor R5. The gate of the field effect transistor Q1 is connected to the negative pole of the voltage regulator diode ZD1. The positive pole of the voltage regulator diode ZD1 is grounded. The gate of the field effect transistor Q1 is connected to the negative pole of the diode D1, the diode D2 and the diode D3 through resistors R1, R2, R3 and R4 connected in series. The source of the field effect transistor Q1 is connected to the input end of the chip U4, and the output end of the chip U4 is respectively connected to the VREF reference voltage module 3 and the control module 4.

[0008] In some embodiments, the VREF reference voltage module includes a chip U2 of model LMV321, the power input end of the chip U2 is connected to the output end of the chip U4, the output end of the chip U2 is connected to the output end of the voltage sampling module, and the output end of the chip U2 is connected to the IN- pin of the chip U2 through a resistor R31.

[0009] In some embodiments, the control module includes a chip U3 with model number HC32F005, the power input terminal of the chip U3 is connected to the output terminal of the chip U4, the three output terminals of the voltage sampling module are respectively connected to pins P01, pin P24 and pin P34 of the chip U4, pin P35 of the chip U3 is connected to the input terminal of the TTL communication isolation module as a signal output terminal, and pin P36 of the chip U3 is connected to the output terminal of the TTL communication isolation module as a signal receiving terminal.

[0010] In some embodiments, the TTL communication isolation module includes an optocoupler element U1 and an optocoupler element U5, both of which are model EL357, wherein pin 1 of the optocoupler element U1 is connected to the output end of the chip U4, pin 2 of the optocoupler element U1 is connected to pin P35 of the chip U3, pin 3 of the optocoupler element U1 is connected to pin 1 of the optocoupler element U5 through resistor R33, pin 4 of the optocoupler element U1 is connected to pin 2 of the optocoupler element U5, pin 3 of the optocoupler element U5 is grounded, and pin 4 of the optocoupler element U5 is connected to pin P36 of the chip U3 and the output end of the chip U4.

[0011] According to another aspect of the present disclosure, a voltage measurement method is provided, comprising the following steps: a voltage sampling module samples the voltage to be measured and sends it to a control module; a power conversion module converts the voltage to be measured into direct current to power a VREF reference voltage module and a control module; and a TTL communication isolation module isolates the output signal of the control module.

[0012] The voltage measurement device and method provided by the present disclosure directly connect the voltage to be measured to draw power through the voltage sampling module, and perform signal isolation and transmission after calculation through the control module, which ensures that the voltage measurement device is small in size and reduces the space occupied while ensuring the accuracy of voltage measurement. The transmission after signal isolation solves the problem of common-mode interference and further improves the accuracy of voltage measurement.

[0013] In addition, in the technical solution disclosed in the present invention, unless otherwise specified, the technical solution can be implemented by adopting conventional means in the art. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0015] Figure 1 A schematic diagram of the structure of a voltage measuring device provided in one embodiment of the present disclosure.

[0016] Figure 2 A circuit diagram of a voltage sampling module and a power conversion module in a voltage measurement device provided in an embodiment of the present disclosure.

[0017] Figure 3 A circuit diagram of a VREF reference voltage module in a voltage measurement device provided in an embodiment of the present disclosure.

[0018] Figure 4 A circuit diagram of a control module and a TTL communication isolation module in a voltage measurement device provided in an embodiment of the present disclosure.

[0019] Figure 5 A flowchart of a voltage measurement method provided by an embodiment of the present disclosure. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0021] Embodiment 1:

[0022] In this embodiment, refer to the attached manual Figure 1-4 , a voltage measuring device is provided, including a voltage sampling module 1, a power conversion module 2, a VREF reference voltage module 3, a control module 4 and a TTL communication isolation module 5, the input ends of the voltage sampling module 1 and the power conversion module 2 are both connected to the voltage to be measured, the output end of the voltage sampling module 1 is connected to the control module 4, the output end of the power conversion module 2 is respectively connected to the VREF reference voltage module 3 and the control module 4, the output end of the VREF reference voltage module 3 is connected to the voltage sampling module 1, and the output end of the control module 4 is connected to the TTL communication isolation module 5.

[0023] In an optional embodiment, the voltage sampling module 1 includes three groups of series resistors, one end of the three groups of series resistors are respectively connected to the A phase, B phase and C phase of the voltage to be measured, and the other end is connected to the control module 4 as three output ends. Thus, the voltage signal collected by the series-connected voltage-dividing resistors is sent to the control module for calculation, thereby improving the measurement accuracy.

[0024] In an optional embodiment, the series resistors may all be high-precision resistors to further improve the accuracy of voltage measurement.

[0025] In an alternative embodiment, each set of series resistors includes five resistors.

[0026] In an optional embodiment, the power conversion module 2 includes a half-wave rectifier circuit, a field effect transistor Q1 and a chip U4 with model LR7533. The half-wave rectifier circuit includes a diode D1, a diode D2 and a diode D3. The positive poles of the diodes D1, D2 and D3 are respectively connected to the A phase, B phase and C phase of the voltage to be measured. The negative poles of the diodes D1, D2 and D3 are connected together and then connected to the positive pole of the diode D4. The negative pole of the diode D4 is connected to the drain of the field effect transistor Q1 through a resistor R5. The gate of the field effect transistor Q1 is connected to the negative pole of the voltage regulator diode ZD1. The positive pole of the voltage regulator diode ZD1 is grounded. The gate of the field effect transistor Q1 is connected to the negative pole of the diode D1, the diode D2 and the diode D3 through resistors R1, R2, R3 and R4 connected in series. The source of the field effect transistor Q1 is connected to the input end of the chip U4. The output end of the chip U4 is respectively connected to the VREF reference voltage module 3 and the control module 4. Therefore, the voltage to be measured after passing through the rectifier diode is used to power the gate of the field effect tube after passing through the current limiting resistors R1 to R4, and then after passing through the field effect tube and the voltage regulator chip U4, it is used to power the control module 4.

[0027] In an optional embodiment, the VREF reference voltage module 3 includes a chip U2 of model LMV321, the power input end of the chip U2 is connected to the output end of the chip U4, the output end of the chip U2 is connected to the output end of the voltage sampling module 1, and the output end of the chip U2 is connected to the IN- pin of the chip U2 through a resistor R31. In an optional embodiment, the chip U2 can provide a bias voltage of 1.65V. Thus, the chip U2 provides a bias voltage so that the voltage signal is positive and can be input into the control module.

[0028] In an optional embodiment, the control module 4 includes a chip U3 of model HC32F005, the power input terminal of the chip U3 is connected to the output terminal of the chip U4, the three output terminals of the voltage sampling module 1 are respectively connected to the pins P01, P24 and P34 of the chip U4, the pin P35 of the chip U3 is connected to the input terminal of the TTL communication isolation module 5 as a signal output terminal, and the pin P36 of the chip U3 is connected to the output terminal of the TTL communication isolation module 5 as a signal receiving terminal.

[0029] In an optional embodiment, the TTL communication isolation module 5 includes an optocoupler U1 and an optocoupler U5, both of which are EL357 models. Pin 1 of the optocoupler U1 is connected to the output end of the chip U4, pin 2 of the optocoupler U1 is connected to pin P35 of the chip U3, pin 3 of the optocoupler U1 is connected to pin 1 of the optocoupler U5 through a resistor R33, pin 4 of the optocoupler U1 is connected to pin 2 of the optocoupler U5, pin 3 of the optocoupler U5 is grounded, and pin 4 of the optocoupler U5 is connected to pin P36 of the chip U3 and the output end of the chip U4. Thus, the TTL level signal to be transmitted is isolated before being transmitted, which solves the problem of common mode interference, has low signal transmission distortion, and has a good isolation effect, so that measurement and communication are isolated and signal reliability is improved.

[0030] The voltage measuring device provided by the present invention is directly connected to the voltage to be measured to draw power through the voltage sampling module, and the signal is isolated and transmitted after calculation by the control module, which ensures that the voltage measuring device is small in size and reduces the space occupied, while ensuring the accuracy of voltage measurement. The transmission after signal isolation solves the problem of common mode interference and further improves the accuracy of voltage measurement.

[0031] Embodiment 2:

[0032] In this embodiment, refer to the attached manual Figure 5 , provides a voltage measurement method, which is applied to any voltage measurement device in the above product embodiments, comprising the following steps:

[0033] S101: The voltage sampling module samples the voltage to be measured and sends it to the control module;

[0034] S102: The power conversion module converts the voltage to be tested into direct current to supply power to the VREF reference voltage module and the control module;

[0035] S103: The TTL communication isolation module isolates the output signal of the control module.

[0036] The voltage measurement method provided by the present invention directly connects the voltage to be measured to take power through the voltage sampling module, and transmits the signal after calculation through the control module. This ensures that the voltage measurement device is small in size and reduces the space occupied, while ensuring the accuracy of voltage measurement. The transmission after signal isolation solves the problem of common-mode interference, further improving the accuracy of voltage measurement.

[0037] The above is only an optional implementation of the present disclosure. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present disclosure. These improvements and modifications should also be regarded as the scope of protection of the present disclosure.

Claims

1. A voltage measuring device, characterized in that It includes a voltage sampling module (1), a power conversion module (2), a VREF reference voltage module (3), a control module (4) and a TTL communication isolation module (5), The input ends of the voltage sampling module (1) and the power conversion module (2) are both connected to the voltage to be measured. The output end of the voltage sampling module (1) is connected to the control module (4), The output end of the power conversion module (2) is connected to the VREF reference voltage module (3) and the control module (4) respectively. The output end of the VREF reference voltage module (3) is connected to the voltage sampling module (1), The output end of the control module (4) is connected to the TTL communication isolation module (5); The voltage sampling module (1) comprises three groups of series resistors, one end of the three groups of series resistors are respectively connected to the A phase, the B phase and the C phase of the voltage to be measured, and the other ends are connected to the control module (4) as three output ends; The power conversion module (2) comprises a half-wave rectifier circuit, a field effect transistor Q1 and a chip U4 of model LR7533, wherein the half-wave rectifier circuit comprises a diode D1, a diode D2 and a diode D3, wherein the positive electrodes of the diode D1, the diode D2 and the diode D3 are respectively connected to the A phase, the B phase and the C phase of the voltage to be measured, wherein the negative electrodes of the diode D1, the diode D2 and the diode D3 are connected together and then connected to the positive electrode of the diode D4, wherein the negative electrode of the diode D4 is connected to the drain of the field effect transistor Q1 via a resistor R5, wherein the gate of the field effect transistor Q1 is connected to the negative electrode of the voltage stabilizing diode ZD1, wherein the positive electrode of the voltage stabilizing diode ZD1 is grounded, wherein the gate of the field effect transistor Q1 is connected to the negative electrode of the diode D1, the diode D2 and the diode D3 via a resistor R1, a resistor R2, a resistor R3 and a resistor R4 connected in series, wherein the source of the field effect transistor Q1 is connected to the input end of the chip U4, and the output end of the chip U4 is respectively connected to the VREF reference voltage module 3 and the control module 4; The VREF reference voltage module (3) comprises a chip U2 of model LMV321, the power input end of the chip U2 is connected to the output end of the chip U4, the output end of the chip U2 is connected to the output end of the voltage sampling module (1), the output end of the chip U2 is connected to the IN-pin of the chip U2 via a resistor R31, and the chip U2 can provide a bias voltage of 1.65V; The control module (4) comprises a chip U3 of model HC32F005, the power input end of the chip U3 is connected to the output end of the chip U4, the three output ends of the voltage sampling module (1) are respectively connected to the pin P01, the pin P24 and the pin P34 of the chip U4, the pin P35 of the chip U3 is connected to the input end of the TTL communication isolation module (5) as a signal output end, and the pin P36 of the chip U3 is connected to the output end of the TTL communication isolation module (5) as a signal receiving end; The TTL communication isolation module (5) comprises an optocoupler element U1 and an optocoupler element U5, both of which are EL357 models. Pin 1 of the optocoupler element U1 is connected to the output end of the chip U4, pin 2 of the optocoupler element U1 is connected to pin P35 of the chip U3, pin 3 of the optocoupler element U1 is connected to pin 1 of the optocoupler element U5 via a resistor R33, pin 4 of the optocoupler element U1 is connected to pin 2 of the optocoupler element U5, pin 3 of the optocoupler element U5 is grounded, and pin 4 of the optocoupler element U5 is connected to pin P36 of the chip U3 and the output end of the chip U4.

2. The voltage measuring device according to claim 1, characterized in that: Each group of the series resistors includes five resistors.

3. A voltage measurement method, characterized in that: The voltage measuring device used in any one of claims 1 to 2 comprises the following steps: The voltage sampling module samples the voltage to be measured and sends it to the control module. The power conversion module converts the voltage to be tested into direct current to power the VREF reference voltage module and the control module. The TTL communication isolation module isolates the output signal of the control module.

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