Rogowski coil signal acquisition circuit, chip, circuit breaker and low-voltage power distribution system

Abstract

The utility model provides a Rogowski coil signal acquisition circuit, a chip, a circuit breaker and a low-voltage power distribution system, the Rogowski coil signal acquisition circuit provided by the embodiment comprises a first integrating circuit and a second integrating circuit which are connected in parallel, and the first integrating circuit comprises a first integrator and an amplifying circuit which are connected in sequence. The input end of the first integrator is electrically connected with the output end of the Rogowski coil, and the integral time constant of the first integrator is smaller than a first threshold value. The second integrating circuit comprises a second integrator, the input end of the second integrator is electrically connected with the output end of the Rogowski coil, the integrating time constant of the second integrator is larger than a second threshold value, and the first threshold value is smaller than the second threshold value. A single Rogowski coil is used for detecting large signals of short-circuit current, sampling precision is taken into account while rapid change is achieved, the problem of phase deviation is effectively solved, different signal conditions in an application environment are dealt with, and measurement precision and protection speed of the circuit breaker are improved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of low-voltage electrical appliances, and in particular to a Rogowski coil signal acquisition circuit, a chip, a circuit breaker, and a low-voltage power distribution system. Background Art

[0002] Circuit breakers (CBs) are widely used in industrial production and daily life. They use electronic trip units to provide circuit protection. The electronic trip unit measures the root mean square current (RMS) and uses an algorithm to determine whether to disconnect the circuit through the trip unit. This can prevent thermal overloads, short circuits, etc., thereby effectively protecting the electrical facilities in the circuit.

[0003] However, the measurement accuracy of current circuit breakers is not high. Utility Model Content

[0004] The present disclosure provides a Rogowski coil signal acquisition circuit, a chip, a circuit breaker, and a low-voltage power distribution system to solve the problem of low measurement accuracy of current circuit breakers.

[0005] In a first aspect, the present disclosure provides a Rogowski coil signal acquisition circuit, comprising: a first integration circuit and a second integration circuit connected in parallel; the first integration circuit comprising a first integrator and an amplifier circuit connected in sequence; an input end of the first integrator being electrically connected to an output end of the Rogowski coil; an integration time constant of the first integrator being less than a first threshold; the second integration circuit comprising a second integrator; an input end of the second integrator being electrically connected to an output end of the Rogowski coil; an integration time constant of the second integrator being greater than a second threshold, and the first threshold being less than the second threshold.

[0006] In one possible design, the first integration circuit also includes a first polarity conversion circuit; the output end of the amplification circuit is electrically connected to the input end of the first polarity conversion circuit; the first polarity conversion circuit is used to convert the input first bipolar signal into a first unipolar signal.

[0007] In a possible design, the output end of the first polarity conversion circuit is electrically connected to the first input end of the processing unit.

[0008] In one possible design, the second integration circuit also includes a second polarity conversion circuit; the output end of the second integrator is electrically connected to the input end of the second polarity conversion circuit; the second polarity conversion circuit is used to convert the input second bipolar signal into a second unipolar signal.

[0009] In a possible design, the output end of the second polarity conversion circuit is electrically connected to the second input end of the processing unit.

[0010] In one possible design, an integration time constant of the first integrator is less than 0.01 seconds.

[0011] In one possible design, an integration time constant of the second integrator is greater than 0.1824 seconds.

[0012] In a second aspect, the present disclosure provides a Rogowski coil signal acquisition chip, comprising the Rogowski coil signal acquisition circuit as described in any one of the first aspects above.

[0013] In a third aspect, the present disclosure provides a circuit breaker, comprising Rogowski coils connected in sequence, a Rogowski coil signal acquisition circuit as described in any one of the first aspects above, and a processing unit.

[0014] In a fourth aspect, the present disclosure provides a low-voltage power distribution system, characterized in that it includes a circuit breaker as described in any one of the third aspects above.

[0015] The Rogowski coil signal acquisition circuit, chip, circuit breaker, and low-voltage power distribution system provided by the embodiments of the present disclosure include a first and second integrator circuits connected in parallel. The first integrator circuit includes a first integrator and an amplifier circuit connected in sequence. The input of the first integrator is electrically connected to the output of the Rogowski coil, and the integration time constant of the first integrator is less than a first threshold. The second integrator circuit includes a second integrator, the input of the second integrator being electrically connected to the output of the Rogowski coil, and the integration time constant of the second integrator being greater than a second threshold, and the first threshold being less than the second threshold. Thus, the Rogowski coil signal acquisition circuit processes the Rogowski coil sensing signal using two integrator circuits. One integrator circuit has a smaller integration time constant, enabling rapid processing of high short-circuit currents in the Rogowski coil sensing signal, a wide sampling range, and rapid response to current changes. The other integrator circuit has a larger integration time constant, enabling the recovery of small currents and achieving higher sampling accuracy. Furthermore, the second integrator circuit has a smaller phase offset. The signal induced by the Rogowski coil is processed by two parallel integrating circuits. A single Rogowski coil is used to detect large short-circuit current signals and rapid changes while taking into account sampling accuracy. The phase offset problem is effectively solved to cope with different signal conditions in the application environment, thereby improving the measurement accuracy and protection speed of the circuit breaker. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic structural diagram of a circuit breaker provided in an embodiment of the present disclosure;

[0017] Figure 2 A schematic structural diagram of a Rogowski coil signal acquisition circuit provided in an embodiment of the present disclosure;

[0018] Figure 3A schematic structural diagram of another Rogowski coil signal acquisition circuit provided in an embodiment of the present disclosure;

[0019] Figure 4 A schematic structural diagram of another Rogowski coil signal acquisition circuit provided in an embodiment of the present disclosure;

[0020] Reference numerals:

[0021] 100: Circuit breaker; 110: Rogowski coil; 120: Rogowski coil signal acquisition circuit; 130: Processing unit; 200: Rogowski coil signal acquisition circuit; 210: First integration circuit; 220: Second integration circuit; 211: First integrator; 212: Amplification circuit; 213: First polarity conversion circuit; 221: Second integrator; 222: Second polarity conversion circuit. DETAILED DESCRIPTION

[0022] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all possible embodiments consistent with the present disclosure. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present disclosure, as detailed in the appended claims.

[0023] In the present disclosure, "at least one" refers to one or more, and "plurality" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: the existence of A alone, the existence of A and B at the same time, and the existence of B alone, where A and B can be singular or plural. The character " / " generally indicates that the objects associated before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a alone, b alone, or c alone can represent: a alone, b alone, c alone, a and b in combination, a and c in combination, b and c in combination, or a, b, and c in combination, where a, b, and c can be single or multiple. In addition, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance.

[0024] The directions or positional relationships indicated by terms such as "center", "longitudinal", "lateral", "up", "down", "left", "right", "front", and "back" are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present disclosure and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operate in a specific direction, and therefore should not be understood as limiting the present disclosure.

[0025] The terms "connected" and "connect" should be interpreted broadly. For example, "connected" or "connected" in a circuit structure can refer not only to a physical connection, but also to an electrical connection or a signal connection. For example, it can be a direct connection, i.e., a physical connection, or an indirect connection through at least one intermediate component, as long as the circuit is interconnected. It can also refer to internal connectivity between two components. Signal connection can refer not only to signal connection through circuits but also to signal connection through media, such as radio waves. Those skilled in the art will understand the specific meanings of the above terms in this application on a case-by-case basis.

[0026] In order to enable those skilled in the art to better understand the solutions of the present disclosure, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings.

[0027] Circuit breakers are widely used in industrial production and daily life. They use electronic trip units to provide circuit protection. The electronic trip unit measures the root mean square current (RMS) and uses an algorithm to determine whether to disconnect the circuit through the trip unit. This can prevent thermal overloads, short circuits, and other events, thereby effectively protecting the electrical facilities in the circuit.

[0028] Circuit breakers feature a make-break (MCR) function, which is active only for a short, preset time after the circuit breaker is closed. In this case, the circuit breaker must quickly detect a fault after power-up, generate a trip signal, and then disconnect. Fast stabilization is a key requirement throughout the entire process.

[0029] In addition, the circuit breaker also has to undertake the task of collecting some electrical parameters, such as power and electric energy, etc. This requires the circuit breaker to have higher current sampling accuracy and smaller phase offset as a basis.

[0030] Based on the above situation, the present disclosure provides a Rogowski coil signal acquisition circuit that can be used in a circuit breaker. The circuit breaker provided by the present disclosure is introduced below with specific embodiments.

[0031] See also Figure 1 , Figure 1 This is a schematic diagram of the structure of a circuit breaker provided in an embodiment of the present disclosure. The circuit breaker 100 provided in this embodiment includes a Rogowski coil 110, a Rogowski coil signal acquisition circuit 120, and a processing unit 130. The output end of the Rogowski coil 110 is electrically connected to the input end of the Rogowski coil signal acquisition circuit 120, and the output end of the Rogowski coil signal acquisition circuit 120 is electrically connected to the first input end of the processing unit 130.

[0032] The Rogowski coil, also known as a Rogowski coil, a Rogowski coil 110, or an air-core coil, is referred to herein as a Rogowski coil 110. A Rogowski coil 110 is an AC current sensor. It is a hollow, ring-shaped coil, available in either flexible or rigid configurations, and can be directly applied to a conductor to measure AC current. Typically, a Rogowski coil 110 is installed in a circuit breaker to measure signals and output an induced signal.

[0033] The Rogowski coil signal acquisition circuit 120 is used to restore the signal sensed by the Rogowski coil 110 to the signal measured by the Rogowski coil 110 to obtain the original signal.

[0034] The processing unit 130 is used to make connection and disconnection judgments based on the original signal.

[0035] Furthermore, the processing unit 130 may be a microcontroller unit (MCU).

[0036] In actual applications, the signal sensed at the output end of the Rogowski coil 110 is input to the Rogowski coil signal acquisition circuit 120. The Rogowski coil signal acquisition circuit 120 restores the signal measured by the Rogowski coil 110, that is, the original signal, and outputs the original signal. The first input end of the processing unit 130 receives the original signal and performs a separation judgment based on the restored signal.

[0037] A Rogowski coil signal acquisition circuit provided by the present disclosure is described below with reference to a specific embodiment.

[0038] See also Figure 2 , Figure 2 This is a structural diagram of a Rogowski coil signal acquisition circuit provided in an embodiment of the present disclosure. The Rogowski coil signal acquisition circuit 200 provided in this embodiment may include but is not limited to: a first integration circuit 210 and a second integration circuit 220 connected in parallel.

[0039] The first integration circuit 210 includes a first integrator 211 and an amplifier circuit 212 connected in sequence.

[0040] The input end of the first integrator 211 is electrically connected to the output end of the Rogowski coil. The first integrator 211 is used to integrate the input induction signal of the Rogowski coil. The integration time constant of the first integrator 211 is less than the first threshold.

[0041] An input end of the amplifier circuit 212 is electrically connected to an output end of the first integrator 211. The amplifier circuit 212 is configured to amplify a signal input to the amplifier circuit 212.

[0042] Furthermore, the amplifying circuit 212 may include a non-inverting amplifier.

[0043] The second integration circuit 220 includes a second integrator 221 .

[0044] The input end of the second integrator 221 is electrically connected to the output end of the Rogowski coil. The second integrator 221 is used to integrate the input induced signal of the Rogowski coil. The integration time constant of the second integrator 221 is greater than the second threshold, and the first threshold is less than the second threshold.

[0045] In practical applications, the voltage induced at the output of a Rogowski coil is proportional to its rate of change over time. The current flowing through the coil has a 90° phase shift with the coil's output voltage. Because the coil's output is proportional to the temporal derivative of the current flowing through it, a differential structure, the original current signal measured by the coil can be detected using an integrator. Furthermore, for applications requiring power measurement, the phase difference between current and voltage is also important.

[0046] The relationship between the phase error and the integration time constant of the integrator can be expressed by the following formula (1).

[0047]

[0048] Where Φ is the phase error, X C is the capacitive impedance of the integrator, R is the resistance of the resistor in the integrator, C is the capacitance of the capacitor in the integrator, and f is the frequency.

[0049] The following formula (2) can be derived from formula (1).

[0050]

[0051] Setting the integration time constant of the integrator to a smaller value allows for a quick response to current changes. Therefore, the integration time constant of the first integrator 211 is set to be less than the first threshold value, so that the first integration circuit 210 can quickly process the large short-circuit current in the Rogowski coil induced signal, have a large sampling range, and quickly respond to current changes.

[0052] In a possible design, if the signal frequency of the application environment is 50 Hz, in order for the circuit breaker to obtain better breaking performance under this condition, the integration time constant of the first integrator 211 may be less than 0.01 second.

[0053] Setting the integration time constant of the integrator to be larger can control the phase error. Therefore, setting the integration time constant of the second integrator 221 to be greater than the second threshold value allows the second integration circuit 220 to obtain a smaller phase error. In addition, the amplification factor of the second integration circuit 220 is larger, and the sampling accuracy is higher.

[0054] In a possible design, if the phase error Φ is controlled within 1° in an application environment and the signal frequency in the application environment is 50 Hz, the integration time constant of the second integrator 221 may be greater than 0.1824 seconds.

[0055] The Rogowski coil signal acquisition circuit provided in this embodiment includes a first integrator circuit and a second integrator circuit connected in parallel. The first integrator circuit includes a first integrator and an amplifier circuit connected in sequence. The input of the first integrator is electrically connected to the output of the Rogowski coil, and the integration time constant of the first integrator is less than a first threshold. The second integrator circuit includes a second integrator, the input of the second integrator being electrically connected to the output of the Rogowski coil, and the integration time constant of the second integrator being greater than a second threshold, and the first threshold being less than the second threshold. Thus, the Rogowski coil signal acquisition circuit processes the Rogowski coil induced signal using two integrator circuits. The integration time constant of one integrator circuit is set to be small, enabling rapid processing of large short-circuit currents in the Rogowski coil induced signal, widening the sampling range, and rapidly responding to current changes. The integration time constant of the other integrator circuit is set to be large, enabling smaller phase error, enabling the recovery of small currents, and achieving higher sampling accuracy. Furthermore, the second integrator circuit has a smaller phase offset. The signal induced by the Rogowski coil is processed by two parallel integrating circuits. A single Rogowski coil is used to detect large short-circuit current signals and rapid changes while taking into account sampling accuracy. The phase offset problem is effectively solved to cope with different signal conditions in the application environment, thereby improving the measurement accuracy and protection speed of the circuit breaker.

[0056] In some embodiments, Figure 2 Based on the Rogowski coil signal acquisition circuit shown above, the first integration circuit can further include a first polarity conversion circuit to convert a bipolar signal into a unipolar signal for subsequent processing by the analog-to-digital conversion module in the processing unit. This will be described in detail below using specific embodiments.

[0057] See also Figure 3 , Figure 3 This is a structural diagram of another Rogowski coil signal acquisition circuit provided by an embodiment of the present disclosure. Figure 3 is Figure 2 On the basis of the above, the first integration circuit 210 provided in this embodiment further includes a first polarity conversion circuit 213. The output end of the amplifier circuit 212 is electrically connected to the input end of the first polarity conversion circuit 213. The first polarity conversion circuit 213 is used to convert the input first bipolar signal into a first unipolar signal.

[0058] In a possible design, the output end of the first polarity conversion circuit 213 is electrically connected to the first input end of the processing unit. The processing unit is used to make on / off judgments based on the original signal output by the Rogowski coil signal acquisition circuit. The processing unit can be the above-mentioned Figure 1 The processing unit 130 in the illustrated embodiment.

[0059] In actual applications, since the input of the analog-to-digital conversion unit in the processing unit is a unipolar signal, the first polarity conversion circuit 213 is connected after the amplifying circuit 212, and the amplifying circuit 212 outputs a first bipolar signal. The first polarity conversion circuit 213 converts the first bipolar signal into a first unipolar signal, which is convenient for the analog-to-digital conversion unit in the processing unit to collect and process the data, and then the processing unit can perform disconnection judgment, etc.

[0060] The Rogowski coil signal acquisition circuit provided in this embodiment includes a first integrator circuit and a second integrator circuit connected in parallel. The first integrator circuit includes a first integrator, an amplifier circuit, and a first polarity conversion circuit connected in sequence. The input of the first integrator is electrically connected to the output of the Rogowski coil, and the integration time constant of the first integrator is less than a first threshold. The second integrator circuit includes a second integrator, the input of the second integrator being electrically connected to the output of the Rogowski coil, and the integration time constant of the second integrator being greater than a second threshold, and the first threshold being less than the second threshold. Thus, the Rogowski coil signal acquisition circuit processes the Rogowski coil induced signal using two integrator circuits. One integrator circuit has a relatively small integration time constant, enabling rapid processing of high short-circuit currents in the Rogowski coil induced signal, widening the sampling range and rapidly responding to current changes. Furthermore, the first polarity conversion circuit converts the signal into a unipolar signal that can be processed by the processing unit, improving ease of use. The other integrator circuit has a relatively large integration time constant, enabling the recovery of small currents and achieving higher sampling accuracy. Furthermore, the second integrator circuit has a relatively small phase offset. The signal induced by the Rogowski coil is processed by two parallel integrating circuits. A single Rogowski coil is used to detect large short-circuit current signals and rapid changes while taking into account sampling accuracy. The phase offset problem is effectively solved to cope with different signal conditions in the application environment, thereby improving the measurement accuracy and protection speed of the circuit breaker.

[0061] In some embodiments, Figure 2 Based on the Rogowski coil signal acquisition circuit shown above, the second integration circuit can further include a second polarity conversion circuit to convert the bipolar signal into a unipolar signal for subsequent processing by the analog-to-digital conversion module in the processing unit. This will be described in detail below using specific embodiments.

[0062] Please continue reading Figure 3 , Figure 3This is a structural diagram of another Rogowski coil signal acquisition circuit provided by an embodiment of the present disclosure. Figure 3 is Figure 2 On the basis of the above, the second integration circuit 220 provided in this embodiment further includes a second polarity conversion circuit 222. The output end of the second integrator 221 is electrically connected to the input end of the second polarity conversion circuit 222. The second polarity conversion circuit 222 is used to convert the input second bipolar signal into a second unipolar signal.

[0063] In a possible design, the output end of the second polarity conversion circuit 222 is electrically connected to the second input end of the processing unit. The processing unit is used to make on / off judgments based on the original signal output by the Rogowski coil signal acquisition circuit. The processing unit can be the above-mentioned Figure 1 The processing unit 130 in the illustrated embodiment.

[0064] In practical applications, since the input of the analog-to-digital conversion unit in the processing unit is a unipolar signal, a second polarity conversion circuit 222 is connected after the second integrator 221, and the second integrator 221 outputs a second bipolar signal. The second bipolar signal is converted into a second unipolar signal through the second polarity conversion circuit 222, which facilitates the use of the analog-to-digital conversion unit in the processing unit for collection and processing, and then the processing unit can perform disconnection judgment, etc.

[0065] The Rogowski coil signal acquisition circuit provided in this embodiment includes a first integrator circuit and a second integrator circuit connected in parallel. The first integrator circuit includes a first integrator, an amplifier circuit, and a first polarity conversion circuit connected in sequence. The input of the first integrator is electrically connected to the output of the Rogowski coil, and the integration time constant of the first integrator is less than a first threshold. The second integrator circuit includes a second integrator and a second polarity conversion circuit connected in sequence. The input of the second integrator is electrically connected to the output of the Rogowski coil, and the integration time constant of the second integrator is greater than a second threshold, while the first threshold is less than the second threshold. Thus, the Rogowski coil signal acquisition circuit processes the Rogowski coil induced signal using two integrator circuits. One integrator circuit has a smaller integration time constant, enabling rapid processing of large short-circuit currents in the Rogowski coil induced signal, widening the sampling range and rapidly responding to current changes. The other integrator circuit has a larger integration time constant, enabling the recovery of small currents and achieving higher sampling accuracy. Furthermore, the second integrator circuit has a smaller phase offset. Furthermore, the first polarity conversion circuit converts the signal into a unipolar signal that can be processed by the processing unit, improving ease of use. The signal induced by the Rogowski coil is processed by two parallel integrating circuits. A single Rogowski coil is used to detect large short-circuit current signals and rapid changes while taking into account sampling accuracy. The phase offset problem is effectively solved to cope with different signal conditions in the application environment, thereby improving the measurement accuracy and protection speed of the circuit breaker.

[0066] Below Figure 4 Taking the Rogowski coil signal acquisition circuit shown in FIG. 1 as an example, the Rogowski coil signal acquisition circuit provided by the embodiment of the present disclosure is described in detail.

[0067] See also Figure 4 , Figure 4 This is a structural diagram of another Rogowski coil signal acquisition circuit provided in an embodiment of the present disclosure. The Rogowski coil signal acquisition circuit provided in this embodiment includes a precision channel and a fast channel connected in parallel.

[0068] lie in Figure 4 The upper branch is the precision channel, corresponding to the second integrator circuit 220 in the above embodiment. The precision channel includes two stages, distinguished by arrows and denoted by signal flow. The direction indicated by the arrows indicates increasing circuit stages. The first stage in the precision channel is an integrator, corresponding to the second integrator 221 in the above embodiment. The second stage is a polarity conversion circuit, corresponding to the second polarity conversion circuit 222 in the above embodiment.

[0069] The precision measurement channel has a large integration time constant. The integrator amplifies the signal, followed by a polarity conversion unit. This channel can be used to restore tiny signals, achieving higher sampling accuracy and smaller phase offset.

[0070] lie in Figure 4 The lower branch is the fast channel, corresponding to the first integrator circuit in the above embodiment. The fast channel includes three stages, which are distinguished by arrows and indicate signal flow. The direction indicated by the arrows indicates increasing circuit stages. The first stage in the fast channel is an integrator, corresponding to the first integrator 211 in the above embodiment. The second stage in the fast channel is an amplifier, corresponding to the amplifier circuit 212 in the above embodiment. The third stage in the fast channel is a polarity conversion circuit, corresponding to the first polarity conversion circuit 213 in the above embodiment.

[0071] The fast stabilization channel has a small integration time constant. An integrator amplifies the signal, followed by a non-inverting amplifier and a polarity conversion unit. The fast channel is designed to handle high short-circuit currents, has a wide sampling range, and responds quickly to current changes.

[0072] An embodiment of the present disclosure provides a Rogowski coil signal acquisition chip, which includes a Rogowski coil signal acquisition circuit as described in any of the above embodiments.

[0073] The Rogowski coil signal acquisition chip provided in this embodiment includes a first and second integrator circuits connected in parallel. The first integrator circuit includes a first integrator and an amplifier circuit connected in sequence. The input of the first integrator is electrically connected to the output of the Rogowski coil, and the integration time constant of the first integrator is less than a first threshold. The second integrator circuit includes a second integrator, whose input is electrically connected to the output of the Rogowski coil, and whose integration time constant is greater than a second threshold, with the first threshold being less than the second threshold. Thus, the Rogowski coil signal acquisition circuit processes the Rogowski coil induced signal using two integrator circuits. One integrator circuit has a smaller integration time constant, enabling rapid processing of large short-circuit currents in the Rogowski coil induced signal, widening the sampling range, and rapidly responding to current changes. The other integrator circuit has a larger integration time constant, enabling the recovery of small currents and achieving higher sampling accuracy. Furthermore, the second integrator circuit has a smaller phase offset. By processing the Rogowski coil induced signal using two parallel integrator circuits, a single Rogowski coil can be used to detect large and rapidly changing short-circuit currents while maintaining sampling accuracy. This effectively addresses the phase offset issue, adapts to diverse signal conditions in application environments, and improves measurement accuracy and protection speed of the circuit breaker.

[0074] An embodiment of the present disclosure provides a circuit breaker comprising a Rogowski coil, a Rogowski coil signal acquisition circuit, and a processing unit connected in sequence. The Rogowski coil signal acquisition chip comprises the Rogowski coil signal acquisition circuit described in any of the above embodiments. The Rogowski coil is the Rogowski coil described in any of the above embodiments, and the processing unit is the processing unit described in any of the above embodiments.

[0075] The circuit breaker provided in this embodiment includes a Rogowski coil, a Rogowski coil signal acquisition circuit, and a processing unit connected in sequence. The Rogowski coil signal acquisition circuit includes a first and a second integrator circuit connected in parallel. The first integrator circuit includes a first integrator and an amplifier circuit connected in sequence. The input of the first integrator is electrically connected to the output of the Rogowski coil, and the integration time constant of the first integrator is less than a first threshold. The second integrator circuit includes a second integrator, the input of the second integrator being electrically connected to the output of the Rogowski coil, and the integration time constant of the second integrator being greater than a second threshold, and the first threshold being less than the second threshold. Thus, the Rogowski coil signal acquisition circuit processes the Rogowski coil induced signal using two integrator circuits. One integrator circuit has a relatively small integration time constant, enabling rapid processing of high short-circuit currents in the Rogowski coil induced signal, widening the sampling range, and rapidly responding to current changes. The other integrator circuit has a relatively large integration time constant, enabling the recovery of small currents and achieving higher sampling accuracy. Furthermore, the second integrator circuit has a relatively small phase offset. The signal induced by the Rogowski coil is processed by two parallel integrating circuits. A single Rogowski coil is used to detect large short-circuit current signals and rapid changes while taking into account sampling accuracy. The phase offset problem is effectively solved to cope with different signal conditions in the application environment, thereby improving the measurement accuracy and protection speed of the circuit breaker.

[0076] An embodiment of the present disclosure provides a low-voltage power distribution system, which includes the circuit breaker mentioned in the above embodiment.

[0077] This embodiment provides a low-voltage power distribution system including a circuit breaker, which includes a Rogowski coil, a Rogowski coil signal acquisition circuit, and a processing unit connected in sequence. The Rogowski coil signal acquisition circuit includes a first and a second integrator circuit connected in parallel. The first integrator circuit includes a first integrator and an amplifier circuit connected in sequence. The input of the first integrator is electrically connected to the output of the Rogowski coil, and the integration time constant of the first integrator is less than a first threshold. The second integrator circuit includes a second integrator, the input of the second integrator being electrically connected to the output of the Rogowski coil, and the integration time constant of the second integrator being greater than a second threshold, and the first threshold being less than the second threshold. Thus, the Rogowski coil signal acquisition circuit processes the Rogowski coil induced signal using two integrator circuits. One integrator circuit has a relatively small integration time constant, enabling rapid processing of high short-circuit currents in the Rogowski coil induced signal, widening the sampling range, and rapidly responding to current changes. The other integrator circuit has a relatively large integration time constant, enabling the recovery of small currents and achieving higher sampling accuracy. Furthermore, the second integrator circuit has a relatively small phase offset. The signal induced by the Rogowski coil is processed by two parallel integrating circuits. A single Rogowski coil is used to detect large short-circuit current signals and rapid changes while taking into account sampling accuracy. The phase offset problem is effectively solved to cope with different signal conditions in the application environment, thereby improving the measurement accuracy and protection speed of the circuit breaker.

[0078] Other embodiments of the present disclosure will readily occur to those skilled in the art after considering the specification and practicing the disclosure herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the present disclosure being indicated by the following claims.

Claims

1. A Rogowski coil signal acquisition circuit, characterized in that: include: A first integration circuit and a second integration circuit are connected in parallel; the first integration circuit includes a first integrator and an amplifier circuit connected in sequence; the input end of the first integrator is electrically connected to the output end of the Rogowski coil; the integration time constant of the first integrator is less than a first threshold; the second integration circuit includes a second integrator; the input end of the second integrator is electrically connected to the output end of the Rogowski coil; the integration time constant of the second integrator is greater than a second threshold, and the first threshold is less than the second threshold.

2. The circuit according to claim 1, wherein: The first integration circuit further includes a first polarity conversion circuit; the output end of the amplification circuit is electrically connected to the input end of the first polarity conversion circuit; the first polarity conversion circuit is used to convert the input first bipolar signal into a first unipolar signal.

3. The circuit according to claim 2, characterized in that The output end of the first polarity conversion circuit is electrically connected to the first input end of the processing unit.

4. The circuit according to claim 1, wherein: The second integration circuit further includes a second polarity conversion circuit; the output end of the second integrator is electrically connected to the input end of the second polarity conversion circuit; the second polarity conversion circuit is used to convert the input second bipolar signal into a second unipolar signal.

5. The circuit according to claim 4, characterized in that The output end of the second polarity conversion circuit is electrically connected to the second input end of the processing unit.

6. The circuit according to any one of claims 1 to 5, characterized in that: The integration time constant of the first integrator is less than 0.01 seconds.

7. The circuit according to any one of claims 1 to 5, characterized in that: The integration time constant of the second integrator is greater than 0.1824 seconds.

8. A Rogowski coil signal acquisition chip, characterized in that: The method comprises the Rogowski coil signal acquisition circuit as described in any one of claims 1 to 7.

9. A circuit breaker, characterized in that: The device comprises Rogowski coils connected in sequence, a Rogowski coil signal acquisition circuit as claimed in any one of claims 1 to 7, and a processing unit.

10. A low voltage power distribution system, characterized in that: Comprising the circuit breaker as claimed in claim 9 above.

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