Three-phase voltage detection circuit and energy storage converter

Abstract

The utility model relates to a three-phase voltage detection circuit and an energy storage converter, and the circuit comprises a resistance network voltage division module which comprises three voltage division circuits, one ends of the three voltage division circuits are connected with a U phase, a V phase and a W phase correspondingly, the other ends of the three voltage division circuits are connected with one another to form a three-phase intersection point, and the three-phase intersection point serves as a virtual center to be connected with a ground wire; the phase voltage acquisition module is used for acquiring phase voltage of any one of a U phase, a V phase and a W phase; the voltage regulation clamping module is connected with the resistance network voltage division module and is used for regulating and clamping each phase voltage and outputting to obtain a stable phase voltage; and the line voltage measurement module is connected with the voltage regulation clamping module and is used for detecting and outputting a line voltage between any two phases according to each stable phase voltage. According to the invention, the accurate measurement of the line voltage among three phases can be realized, and the stability of a circuit system in the measurement process is improved.

Description

Technical Field

[0001] The present application relates to the technical field of energy storage converters, and in particular to a three-phase voltage detection circuit and an energy storage converter. Background Art

[0002] As the core device of an energy storage system, a PCS (Power Conversion System) energy storage converter directly affects the overall efficiency and stability of the energy storage system with its performance and application. The energy storage converter realizes the energy conversion and bidirectional flow between the energy storage battery and the power grid by collecting and detecting the three-phase voltage of the power grid, and can convert direct current into alternating current or convert alternating current into direct current to meet the charging and discharging requirements of the power grid for the energy storage system.

[0003] In the prior art, the detection of three-phase voltage by an energy storage converter mainly relies on transformer isolation or direct voltage detection. Although these methods are widely used, the circuit design is complex, the occupied volume is large, and the cost is high. Summary of the Utility Model

[0004] Based on this, it is necessary to provide a three-phase voltage detection circuit and an energy storage converter with a simple circuit structure and high three-phase voltage measurement accuracy.

[0005] In a first aspect, a three-phase voltage detection circuit is provided, including:

[0006] A resistor network voltage division module, including three voltage division circuits. One end of each of the three voltage division circuits is respectively connected to the corresponding U-phase, V-phase, and W-phase, and the other ends are connected to each other to form a three-phase intersection point, and the three-phase intersection point is used as a virtual center to connect to the ground wire for collecting the phase voltage of any one of the U-phase, V-phase, and W-phase;

[0007] A voltage regulation and clamping module, connected to the resistor network voltage division module, for regulating and clamping each of the phase voltages to output a stable phase voltage;

[0008] A line voltage measurement module, connected to the voltage regulation and clamping module, for detecting and outputting the line voltage between any two phases according to each of the stable phase voltages.

[0009] In one embodiment, the voltage division circuit includes at least two resistors connected in series.

[0010] In one embodiment, the voltage regulation and clamping module includes three regulation and clamping circuits, and the line voltage measurement module includes a processor;

[0011] The input end of the regulation and clamping circuit is connected to the corresponding voltage division circuit, and the output end of the regulation and clamping circuit is connected to the AD analog-to-digital conversion interface of the processor.

[0012] In one embodiment, the adjustment clamping circuit includes:

[0013] A resistor voltage regulation circuit for buffering, amplifying, and impedance matching the phase voltages on each of the voltage division circuits, and outputting the stable phase voltage.

[0014] In one embodiment, the resistor voltage regulation circuit includes a plurality of voltage regulation resistors and an operational amplifier circuit, and the operational amplifier circuit is used for buffering, amplifying, and impedance matching the voltage regulated by the plurality of voltage regulation resistors.

[0015] In one embodiment, the adjustment clamping circuit further includes:

[0016] A clamping diode circuit connected between the plurality of voltage regulation resistors and the operational amplifier circuit for voltage clamping the voltage regulated by the plurality of voltage regulation resistors.

[0017] In one embodiment, the operational amplifier circuit includes a first operational amplifier and a second operational amplifier. The input terminal of the first operational amplifier is connected to the plurality of voltage regulation resistors, the output terminal of the first operational amplifier is connected to the input terminal of the second operational amplifier, and the output terminal of the second operational amplifier is connected to the processor.

[0018] In one embodiment, the voltage regulation resistors include resistor R11, resistor R12, resistor R13, resistor R14, resistor R15, resistor R16, resistor R17; the operational amplifier circuit includes a first operational amplifier, capacitor C1, capacitor C2, capacitor C3;

[0019] Resistor R11, resistor R12, resistor R13, resistor R14, and resistor R15 are connected in series in sequence. One end of resistor R11 is connected to the middle of the two series resistors of the voltage division circuit, and one end of resistor R15 is connected to the positive electrode of the first operational amplifier; one end of resistor R16 is connected to the positive electrode of the first operational amplifier, and the other end is connected to the common ground; one end of resistor R17 is connected to the positive electrode of the first operational amplifier, and the other end is connected to the common ground;

[0020] The negative electrode of the first operational amplifier is connected to the output terminal of the first operational amplifier;

[0021] One end of capacitor C1 is connected between resistor R15 and the positive electrode of the first operational amplifier, and the other end is connected to the common ground; one end of capacitor C2 is connected to the positive voltage source of the first operational amplifier, and the other end is connected to the common ground; one end of capacitor C3 is connected to the negative voltage source of the first operational amplifier, and the other end is connected to the common ground.

[0022] In one embodiment, the clamping diode circuit includes: diode D1 and diode D2.

[0023] The positive electrode of the diode D1 is connected to the common ground, the negative electrode of the diode D1 is connected to the positive electrode of the diode D2 and the positive electrode of the first operational amplifier, and the positive electrode of the diode D2 is connected to the voltage source.

[0024] In one embodiment, the operational amplifier circuit further includes: a second operational amplifier, a resistor R18, and a capacitor C4;

[0025] The positive electrode of the second operational amplifier is connected to the output terminal of the first operational amplifier, the output terminal of the second operational amplifier is connected to one end of the resistor R18, and the negative electrode of the second operational amplifier is connected to the other end of the resistor R18;

[0026] One end of the capacitor C4 is connected to the other end of the resistor R18, and the other end of the capacitor C4 is connected to the common ground.

[0027] In a second aspect, a power storage converter is provided, including the three-phase voltage detection circuit described in the first aspect above.

[0028] The above three-phase voltage detection circuit and the power storage converter have the following beneficial effects:

[0029] (1) The three phases of U, V, and W form a loop through the voltage division circuit, and the intersection point of the three phases is connected to the ground wire GND as the virtual center, improving the accuracy of the phase voltage collected on the three phases, thereby realizing the accurate measurement of the line voltage.

[0030] (2) The phase voltage of each phase is stabilized through the voltage regulation clamping module, avoiding data errors in the subsequent line voltage measurement module caused by high voltage fluctuations, and further realizing the accurate measurement of the line voltage.

[0031] (3) The virtual midpoint GND of U, V, and W is directly connected to the ground terminal GND of the processor in the line voltage measurement module, simplifying the ground wire configuration, reducing the circuit system noise, and improving the stability of the measurement. Description of the Drawings

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present application or in the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0033] Figure 1 It is a module structure block diagram of a three-phase voltage detection circuit in an embodiment;

[0034] Figure 2 is the circuit block diagram of the three-phase voltage detection circuit in an embodiment;

[0035] Figure 3 is a circuit diagram of the adjustment clamping circuit in an embodiment;

[0036] Figure 4 is another circuit diagram of the adjustment clamping circuit in an embodiment;

[0037] Figure 5 is yet another circuit diagram of the adjustment clamping circuit in an embodiment. Detailed implementation manners

[0038] To facilitate the understanding of the present application, the present application will be described more comprehensively below with reference to the relevant drawings. Embodiments of the present application are given in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present application more thorough and comprehensive.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this application belongs. The terms used in the specification of this application herein are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0040] It can be understood that the terms "first", "second", etc. used in the present application can be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from another element. For example, without departing from the scope of the present application, the first resistor can be called the second resistor, and similarly, the second resistor can be called the first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0041] It can be understood that "connection" in the following embodiments should be understood as "electrical connection", "communication connection", etc. if there is an electrical signal or data transfer between the connected circuits, modules, units, etc.

[0042] It can be understood that "at least one" means one or more, and "a plurality" means two or more. "At least part of an element" means part or all of the element.

[0043] As used herein, the singular forms "a", "an" and "the" may also include the plural forms unless the context clearly dictates otherwise. It should also be understood that the terms "comprises / comprising", "has / including", etc. specify the presence of the stated features, integers, steps, operations, components, parts, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof. At the same time, the term "and / or" used in this specification includes any and all combinations of the related listed items.

[0044] As Figure 1 shown, a three-phase voltage detection circuit of an embodiment includes a resistor network voltage division module 1, a voltage regulation and clamping module 2, and a line voltage measurement module 3.

[0045] The resistor network voltage division module 1 includes three voltage division circuits 11. One ends of the three voltage division circuits 11 are respectively connected to the corresponding U-phase, V-phase, and W-phase, and the other ends are connected to each other to form a three-phase intersection point, and the three-phase intersection point is used as a virtual center to connect to the ground wire GND for collecting the phase voltage of any one of the U-phase, V-phase, and W-phase.

[0046] The voltage regulation and clamping module 2 is connected to the resistor network voltage division module 1 for regulating and clamping each phase voltage and outputting a stable phase voltage.

[0047] The line voltage measurement module 3 is connected to the voltage regulation and clamping module 2 for detecting and outputting the line voltage between any two phases according to each stable phase voltage.

[0048] In this embodiment, the U-phase, V-phase, and W-phase are formed into a loop through the voltage division circuit, and the three-phase intersection point is used as a virtual center to connect to the ground wire GND, which improves the accuracy of the phase voltage collected on the three phases, thereby realizing the accurate measurement of the line voltage. The phase voltage of each phase is stabilized by the voltage regulation and clamping module 2, avoiding data errors of the subsequent line voltage measurement module 3 caused by high voltage fluctuations, and further realizing the accurate measurement of the line voltage.

[0049] In one embodiment, as Figure 2 shown, a circuit block diagram of a three-phase voltage detection circuit is provided. Each of the voltage division circuits 11 includes at least two equivalent resistors R connected in series with equal resistance values. The voltage regulation and clamping module 2 includes three regulation and clamping circuits 21. The line voltage measurement module 3 includes a processor.

[0050] The input ends of each of the regulation and clamping circuits 21 are connected between two series resistors of the corresponding voltage division circuit 11, as Figure 2The detection points 1, 2, and 3 shown in the figure. The output terminals of each of the adjustment and clamping circuits 21 are connected to the AD analog-to-digital conversion interface of the processor. Among them, the virtual center is connected to the ground wire GND, and the ground terminal GND of the processor is connected.

[0051] Specifically, the three-way voltage dividing circuits 11 have corresponding U, V, and W phase voltages at the detection points 1, 2, and 3, which are U {phase} , V {phase} , and W {phase} . Each resistance value of the three-way voltage dividing circuits 11 is R. By using GND as the virtual center point, the line voltage V {line1} between the U and V phases can be calculated as follows:

[0052] V {line1} = V {phase} - U (phase} .

[0053] Similarly, the line voltages between any other two phases can be measured.

[0054] In this embodiment, the U, V, and W phases form a loop through six resistors, and the virtual center point GND of U / V / W is directly connected to the ground terminal GND of the processor in the line voltage measurement module 3, simplifying the ground wire configuration, reducing the noise of the circuit system, and improving the stability of the measurement. Among them, the processor can use a DSP chip, an ARM chip, etc.

[0055] In one of the embodiments, as Figure 3 shown, a circuit diagram of an adjustment and clamping circuit 21 is provided. The adjustment and clamping circuit 21 includes a resistor voltage regulation circuit 211. The resistor voltage regulation circuit 211 is used to buffer and amplify the phase voltage on each of the voltage dividing circuits and perform impedance matching to output the stable phase voltage.

[0056] In one of the embodiments, the resistor voltage regulation circuit 211 includes a plurality of voltage regulation resistors and an operational amplifier circuit. The operational amplifier circuit is used to buffer and amplify the voltage adjusted by the plurality of voltage regulation resistors and perform impedance matching. The voltage regulation resistors are used to adjust each phase voltage. The selection and layout of the resistors need to select appropriate resistor values according to the voltage level and cooperate with the processor to perform precise layout to ensure the correct voltage division ratio. The operational amplifier circuit is used to effectively buffer and amplify each phase voltage signal to ensure the quality and accuracy of the signal before the AD conversion of the processor.

[0057] Specifically, the plurality of voltage regulation resistors include resistor R11, resistor R12, resistor R13, resistor R14, resistor R15, resistor R16, resistor R17; the operational amplifier circuit includes a first operational amplifier A1, capacitor C1, capacitor C2, capacitor C3.

[0058] The resistors R11, R12, R13, R14, and R15 are connected in series in sequence. One end of the resistor R11 is connected to the middle of the two series resistors of the voltage dividing circuit. One end of the resistor R15 is connected to the positive pole of the first operational amplifier A1; one end of the resistor R16 is connected to the positive pole of the first operational amplifier A1, and the other end is connected to the common ground; one end of the resistor R17 is connected to the positive pole of the first operational amplifier A1, and the other end is connected to the common ground. The negative pole of the first operational amplifier A1 is connected to the output end of the first operational amplifier A1; one end of the capacitor C1 is connected between the resistor R15 and the positive pole of the first operational amplifier A1, and the other end is connected to the common ground; one end of the capacitor C2 is connected to the positive voltage source of the first operational amplifier A1, and the other end is connected to the common ground; one end of the capacitor C3 is connected to the negative voltage source of the first operational amplifier A1, and the other end is connected to the common ground.

[0059] Specifically, the resistors R11, R12, R13, R14, and R15 are used for voltage division. In this embodiment, the voltage to be adjusted by multiple voltage regulating resistors is 380V high voltage. Considering the withstand voltage limit of each resistor, 5 resistors with equal resistance values are set, all of which are 820 kΩ. The resistors R16 and R17 are used for fine-tuning according to the measurement range of the processor, and the resistance values are equal, set to 10 kΩ. By performing resistance voltage division on the strong electricity input at the detection point through the resistors R11 to R17, a weak voltage after voltage division is obtained. Since the strong electricity has strong noise interference and a large voltage waveform disturbance during the conversion to weak electricity, the weak voltage after voltage division is buffer-amplified and impedance-matched through the first operational amplifier, and the voltage waveform is adjusted to output a high-precision stable phase voltage.

[0060] In this embodiment, through the resistance voltage regulating circuit 211 composed of multiple voltage regulating resistors and the first operational amplifier A1, the impedance matching of the upper circuits of the U, V, and W phases is improved, and the acquisition accuracy of the phase voltage is increased.

[0061] In one of the embodiments, as Figure 4 shown, a circuit diagram of another regulating clamping circuit 21 is provided. The regulating clamping circuit 21 further includes a clamping diode circuit 212, which is connected between the multiple voltage regulating resistors and the operational amplifier circuit.

[0062] Specifically, the clamping diode circuit 212 is connected to the positive pole of the first operational amplifier A1 of the operational amplifier circuit. The clamping diode circuit 212 is used for voltage clamping of the voltage regulated by the multiple voltage regulating resistors.

[0063] Specifically, the clamping diode circuit 212 includes diode D1 and diode D2. The positive electrode of diode D1 is connected to the common ground, the negative electrode of diode D1 is connected to the positive electrode of diode D2 and the positive electrode of the first operational amplifier A1, and the positive electrode of diode D2 is connected to the voltage source.

[0064] Specifically, the weak voltage after voltage division is voltage clamped by diode D1 and diode D2 to limit the amplitude of the input signal and prevent the input signal from exceeding the working range of subsequent circuits or devices, thereby protecting the subsequent circuits from damage or interference.

[0065] In one embodiment, as Figure 5 shown, there is provided another circuit diagram of the adjustable clamping circuit 21. The adjustable clamping circuit 21 further includes a voltage follower module 213. Its input terminal is connected to the output terminal of the first operational amplifier A1 of the resistor voltage regulating circuit 211, and its output terminal is connected to the AD analog-to-digital conversion interface of the processor. It is equivalent to a voltage follower and plays a role of buffering and isolation for stabilizing the phase voltage. It includes a second operational amplifier A2, a resistor R18, and a capacitor C4. Then the operational amplifier circuit includes the first operational amplifier A1 and the second operational amplifier A2. The input terminal of the first operational amplifier A1 is connected to multiple voltage regulating resistors. The output terminal of the first operational amplifier A1 is connected to the input terminal of the second operational amplifier A2, and the output terminal of the second operational amplifier A2 is connected to the processor.

[0066] The positive electrode of the second operational amplifier A2 is connected to the output terminal of the first operational amplifier A1. The output terminal of the second operational amplifier A2 is connected to one end of the resistor R18, and the negative electrode of the second operational amplifier A2 is connected to the other end of the resistor R18. One end of the capacitor C4 is connected to the other end of the resistor R18, and the other end of the capacitor C4 is connected to the common ground.

[0067] Specifically, through the second operational amplifier A2 in the voltage follower module 213, a second impedance matching is performed on the stable phase voltage output by the first operational amplifier A1, enhancing the anti-interference ability of the stable phase voltage. At the same time, the voltage waveform is deeply adjusted to remove burrs and further improve the voltage accuracy. The model of the first operational amplifier can adopt the TL082CDR model, which has low noise, high input impedance, and stable temperature characteristics, and can be adjusted by gain settings to adapt to different voltage range measurement requirements.

[0068] In one embodiment, the resistors in the resistor voltage regulating circuit 211 are 1% precision metal film resistors to ensure the accuracy and long-term stability of resistor voltage division. The diodes D1 and D2 in the clamping diode circuit 212 are low-voltage-drop and high-response-speed diodes to ensure the fast response of voltage regulation.

[0069] In one embodiment, a power storage converter is provided, including a three-phase voltage detection circuit as shown in Figure 2 Figure 2. Among them, the three regulating clamp circuits 21 included in the voltage regulating clamp module 2 are as shown in Figure 5 Figure 3. Each module is used to implement the functions described in the above embodiments.

[0070] Preferably, the three-phase voltage detection circuit described in the above embodiments can also be applied to fields such as renewable energy systems, smart grids, and electric vehicles for voltage detection. In a renewable energy system, voltage detection in, for example, solar and wind energy systems is achieved. In a smart grid, high-precision monitoring of the grid voltage is realized. In an electric vehicle, it is used for voltage detection of the on-vehicle power system.

[0071] In the description of this specification, the description referring to terms such as "some embodiments", "other embodiments", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic description of the above terms does not necessarily refer to the same embodiment or example.

[0072] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0073] The above-described embodiments only represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several deformations and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A three-phase voltage detection circuit, characterized in that: include: A resistor network voltage divider module, comprising a three-way voltage divider circuit, wherein one end of the three-way voltage divider circuit is respectively connected to the corresponding U phase, V phase and W phase, and the other ends are mutually connected to form a three-phase intersection and the three-phase intersection is used as a virtual center to connect the ground wire, so as to collect the phase voltage of any one of the U phase, V phase and W phase; A voltage regulating and clamping module, connected to the resistor network voltage dividing module, for regulating and clamping each of the phase voltages, and outputting a stable phase voltage; The line voltage measuring module is connected to the voltage regulating clamping module and is used to detect and output the line voltage between any two phases according to each of the stable phase voltages.

2. The three-phase voltage detection circuit according to claim 1, characterized in that: The voltage regulation clamping module includes a three-way regulation clamping circuit, and the line voltage measurement module includes a processor; The input end of the regulating clamp circuit is connected to the corresponding voltage divider circuit, and the output end of the regulating clamp circuit is connected to the AD analog-to-digital conversion interface of the processor.

3. The three-phase voltage detection circuit according to claim 2, characterized in that: The regulating clamping circuit comprises: The resistor voltage regulating circuit is used to buffer, amplify and impedance match the phase voltage on each of the voltage dividing circuits to output the stable phase voltage.

4. The three-phase voltage detection circuit according to claim 3, characterized in that: The resistor voltage regulating circuit includes a plurality of voltage regulating resistors and an operational amplifier circuit, and the operational amplifier circuit is used for buffering, amplifying and impedance matching the voltage regulated by the plurality of voltage regulating resistors.

5. The three-phase voltage detection circuit according to claim 4, characterized in that: The regulating clamping circuit also includes: The clamping diode circuit is connected between the plurality of voltage regulating resistors and the operational amplifier circuit, and is used for clamping the voltage regulated by the plurality of voltage regulating resistors.

6. The three-phase voltage detection circuit according to claim 5, characterized in that: The operational amplifier circuit includes a first operational amplifier and a second operational amplifier, the input end of the first operational amplifier is connected to the multiple voltage regulating resistors, the output end of the first operational amplifier is connected to the input end of the second operational amplifier, and the output end of the second operational amplifier is connected to the processor.

7. The three-phase voltage detection circuit according to claim 6, characterized in that: The voltage regulating resistor includes a resistor R11, a resistor R12, a resistor R13, a resistor R14, a resistor R15, a resistor R16, and a resistor R17; the operational amplifier circuit includes a first operational amplifier, a capacitor C1, a capacitor C2, and a capacitor C3; The resistor R11, the resistor R12, the resistor R13, the resistor R14, and the resistor R15 are connected in series in sequence, one end of the resistor R11 is connected to the middle of the two series resistors of the voltage divider circuit, one end of the resistor R15 is connected to the positive electrode of the first operational amplifier; one end of the resistor R16 is connected to the positive electrode of the first operational amplifier, and the other end is connected to the common ground; one end of the resistor R17 is connected to the positive electrode of the first operational amplifier, and the other end is connected to the common ground; The negative electrode of the first operational amplifier is connected to the output end of the first operational amplifier; One end of the capacitor C1 is connected between the resistor R15 and the positive electrode of the first operational amplifier, and the other end is connected to the common ground; one end of the capacitor C2 is connected to the positive voltage source of the first operational amplifier, and the other end is connected to the common ground; one end of the capacitor C3 is connected to the negative voltage source of the first operational amplifier, and the other end is connected to the common ground.

8. The three-phase voltage detection circuit according to claim 7, characterized in that: The clamping diode circuit includes: a diode D1, a diode D2, The anode of the diode D1 is connected to the common ground, the cathode of the diode D1 is connected to the anode of the diode D2 and the anode of the first operational amplifier, and the anode of the diode D2 is connected to a voltage source.

9. The three-phase voltage detection circuit according to claim 7, characterized in that: The operational amplifier circuit further includes: a second operational amplifier, a resistor R18, and a capacitor C4; The positive electrode of the second operational amplifier is connected to the output end of the first operational amplifier, the output end of the second operational amplifier is connected to one end of the resistor R18, and the negative electrode of the second operational amplifier is connected to the other end of the resistor R18; One end of the capacitor C4 is connected to the other end of the resistor R18 , and the other end of the capacitor C4 is connected to a common ground.

10. An energy storage converter, characterized in that: It comprises a three-phase voltage detection circuit as described in any one of claims 1 to 9.

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