Current detection device and control system

Abstract

The utility model provides a current detection device and a control system. The current detection device comprises three detection loops and first controllable switch devices corresponding to the detection loops. The three first controllable switching devices are connected in series in a control loop; each detection loop is used for detecting one-phase current in three-phase current of the heat dissipation device, and generating a first level signal corresponding to the one-phase current and used for disconnecting a first controllable switching device corresponding to the detection loop, or generating a second level signal corresponding to the one-phase current and used for connecting the first controllable switching device corresponding to the detection loop; wherein when the at least one first controllable switching device is disconnected, the control loop is in a disconnected state, and the on-off state of the power supply loop corresponding to the heat dissipation device is determined according to the on-off state of the control loop. According to the invention, the three-phase current of the heat dissipation device can be monitored, safety threats to equipment operation caused by abnormal current faults are reduced, and any phase of current abnormity can trigger faults.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of current detection, in particular to a current detection device and a control system. BACKGROUND

[0002] A plurality of heat dissipation devices are configured to the converter, and when the heat dissipation devices fail, the operation safety of the converter is threatened. In order to monitor the operation state of the heat dissipation devices and ensure the operation safety of the converter, the three-phase currents of the heat dissipation devices need to be detected, and if the currents are detected to be abnormal, the corresponding power supply circuits can be disconnected in time to protect the heat dissipation devices and reduce the risk of failure expansion. CONTENT OF THE UTILITY MODEL

[0003] The purpose of the present application is to provide a current detection device and a control system to protect the heat dissipation devices and thus ensure the safe operation of the converter.

[0004] The purpose of the present application is achieved by adopting the following technical solutions:

[0005] In a first aspect, the present application provides a current detection device, which comprises three detection circuits and a first controllable switching device corresponding to each detection circuit; the three first controllable switching devices are connected in series in a control circuit; each detection circuit is used to detect one-phase current in the three-phase currents of the heat dissipation devices; and a first level signal corresponding to the one-phase current is generated, the first level signal is used to disconnect the first controllable switching device corresponding to the detection circuit, or a second level signal corresponding to the one-phase current is generated, the second level signal is used to turn on the first controllable switching device corresponding to the detection circuit; wherein when at least one first controllable switching device is disconnected, the control circuit is in a disconnected state, and the on-off state of the corresponding power supply circuit of the heat dissipation devices is determined according to the on-off state of the control circuit.

[0006] In some embodiments, the detection circuit comprises an inductive device for inducing an electrical signal corresponding to the one-phase current; and a signal processing module for processing the electrical signal to output the first level signal or the second level signal.

[0007] In some embodiments, the inductive device is a current transformer, and the electrical signal is an alternating current signal; the signal processing module comprises a signal conversion unit and a comparison unit; the signal conversion unit is used to convert the alternating current signal into a direct current voltage signal; and the comparison unit is used to compare a voltage value corresponding to the direct current voltage signal with a target voltage value range to output the first level signal or the second level signal.

[0008] In some embodiments, the comparison unit comprises a first comparison device; the first comparison device is configured to compare the voltage value of the direct current voltage signal with a target voltage value range, and output the first level signal indicating that the voltage value is within the target voltage value range, or output the second level signal indicating that the voltage value is not within the target voltage value range; wherein the on-off state of the power supply circuit of the heat dissipation device is determined according to the disconnection time of the control circuit.

[0009] In some embodiments, the comparison unit comprises a second comparison device and a third comparison device; the second comparison device is configured to compare the voltage value of the direct current voltage signal with a target voltage value range, and output the current normal signal indicating that the voltage value is within the target voltage value range, or output the current abnormal signal indicating that the voltage value is not within the target voltage value range; the third comparison device is configured to compare the current abnormal time of the current abnormal signal with a preset time threshold, and output the first level signal indicating that the current abnormal time is greater than the preset time threshold, or output the second level signal indicating that the current abnormal time is not greater than the preset time threshold; wherein the on-off state of the power supply circuit of the heat dissipation device is determined according to the current abnormal time.

[0010] In some embodiments, the signal conversion unit comprises a rectifier device configured to rectify the alternating current signal to obtain a direct current signal; and a conversion device configured to convert the direct current signal to obtain the direct current voltage signal.

[0011] In some embodiments, the conversion device is an operational amplifier device, which comprises an input resistor configured to sense an input voltage signal corresponding to the direct current signal; and an amplifier configured to amplify the input voltage signal to obtain the direct current voltage signal.

[0012] In some embodiments, the first controllable switch device comprises one or more of a relay, a switch, a contactor, a circuit breaker, an IGBT, and a MOSFET.

[0013] In a second aspect, the present application provides a control system, comprising: any of the current detection devices described above; and a controller configured to receive the first level signal or the second level signal, and output a first control instruction for disconnecting the power supply circuit of the heat dissipation device, or output a second control instruction for keeping the power supply circuit on.

[0014] In some embodiments, the control system further comprises a second controllable switching device in the power supply circuit, configured to disconnect the power supply circuit upon receiving the first control instruction, or keep the power supply circuit on upon receiving the second control instruction.

[0015] In some embodiments, the second controllable switching device comprises one or more of a relay, a switch, a contactor, and a circuit breaker.

[0016] In some embodiments, the controller is further configured to output fault state information corresponding to the first control instruction, or output normal operation state information corresponding to the second control instruction.

[0017] The present application provides a current detection device and a control system. The current detection device comprises three detection circuits and a first controllable switching device corresponding to each detection circuit; the three first controllable switching devices are connected in series in a control circuit; each detection circuit is configured to detect one phase current of three-phase currents of a heat dissipation device; and generate a first level signal corresponding to the one phase current, the first level signal being configured to disconnect the first controllable switching device corresponding to the detection circuit, or generate a second level signal corresponding to the one phase current, the second level signal being configured to keep the first controllable switching device corresponding to the detection circuit on; wherein, when at least one first controllable switching device is disconnected, the control circuit is in a disconnected state, and the on-off state of a power supply circuit corresponding to the heat dissipation device is determined according to the on-off state of the control circuit. The above-mentioned current detection device can monitor the three-phase currents of the heat dissipation device, and reduce the safety threat to the operation of the equipment caused by abnormal failure of the three-phase currents of the heat dissipation device. Specifically, by controlling the disconnection of the power supply circuit of the heat dissipation device, the safety hazard caused by abnormal current can be interrupted in time, the heat dissipation device is protected, and the stable operation of the converter or other related equipment is ensured. Moreover, since the above-mentioned current detection device can detect three-phase currents, any abnormal one-phase current can trigger a fault, which can ensure the accurate triggering of the fault. BRIEF DESCRIPTION OF DRAWINGS

[0018] The present application will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0019] Figure 1 is a structural block diagram of a current detection device provided by an embodiment of the present application.

[0020] Figure 2 is a circuit schematic diagram of a current detection device provided by an embodiment of the present application.

[0021] Figure 3 is a structural block diagram of a detection circuit provided by an embodiment of the present application.

[0022] Figure 4is a structural block diagram of a signal processing module provided by an embodiment of the present application.

[0023] Figure 5 is a structural block diagram of a comparison unit provided by an embodiment of the present application.

[0024] Figure 6 is a structural block diagram of another comparison unit provided by an embodiment of the present application.

[0025] Figure 7 is a structural block diagram of a signal conversion unit provided by an embodiment of the present application.

[0026] Figure 8 is a structural block diagram of a conversion device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the drawings in the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0028] In the description of the embodiments of the present application, it should be understood that the terms "first", "second" are used only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include one or more of the features. In the description of the embodiments of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0029] The converter is configured with multiple heat dissipation devices (for example, fans), and when the heat dissipation devices fail, it will pose a threat to the safe operation of the converter. In order to monitor the operating state of the heat dissipation device and ensure the safe operation of the converter, when the three-phase current of the heat dissipation device is abnormal due to external power supply of the heat dissipation device or abnormality of the heat dissipation device body and other factors, the three-phase current of the heat dissipation device needs to be detected, and when the current is detected to be abnormal, the power supply loop of the heat dissipation device is disconnected in time, the heat dissipation device is protected, and the risk of failure expansion is reduced.

[0030] The embodiments of the present application can monitor the three-phase current of the heat dissipation device in real time, which plays a role in protecting the heat dissipation device.

[0031] It should be noted that although some embodiments in the present application are described by taking the converter scene as an example, the present application is not only applicable to the converter scene, but also applicable to the heat dissipation device in other scenes other than the converter scene.

[0032] Referring toFigure 1 and Figure 2 , Figure 1 is a structural block diagram of a current detection device provided by an embodiment of the present application, Figure 2 is a circuit schematic diagram of a current detection device provided by an embodiment of the present application. Figure 2 In the current detection device, the three-phase current includes an A-phase current, a B-phase current and a C-phase current, and the op amp is an operational amplifier.

[0033] To improve the related art, an embodiment of the present application provides a current detection device, which includes three detection loops 101 and a first controllable switching device 102 corresponding to each detection loop 101; the three first controllable switching devices 102 are connected in series in a control loop; each detection loop 101 is configured to detect one-phase current in three-phase current of a heat dissipation device 201; and generate a first level signal corresponding to the one-phase current, the first level signal being configured to turn off the first controllable switching device 102 corresponding to the detection loop 101, or generate a second level signal corresponding to the one-phase current, the second level signal being configured to turn on the first controllable switching device 102 corresponding to the detection loop 101; wherein, when at least one first controllable switching device 102 is turned off, the control loop is in an off state, and a turn-on / off state of a power supply loop corresponding to the heat dissipation device 201 is determined according to the turn-on / off state of the control loop.

[0034] The above embodiment does not limit the heat dissipation device 201, which may, for example, include a fan. The above embodiment does not limit the application scenario of the heat dissipation device 201, which may, for example, be applied in a current transformer.

[0035] The above embodiment does not limit the first level signal and the second level signal. As an example, the first level signal is a low level signal, and the second level signal is a high level signal. As another example, the first level signal is a high level signal, and the second level signal is a low level signal.

[0036] The above embodiment does not limit the first controllable switching device 102, which may, for example, include one or more of a relay, a switch, a contactor, a circuit breaker, an IGBT (Insulated Gate Bipolar Transistor) and a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor). In some embodiments, the first controllable switching device 102 can be a relay.

[0037] The current detection device can monitor the three-phase current of the heat dissipation device 201, protect the heat dissipation device 201, and reduce the safety threat to the operation of the equipment (for example, a converter) caused by abnormal failure of the three-phase current of the heat dissipation device 201. When the current of one or more phases of the heat dissipation device 201 is abnormal, it may cause the heat dissipation effect to decrease, thereby causing the equipment to overheat, and further affecting the safety and stability of the equipment. For example, when the current of one or more phases is too large, it may indicate that the load of the heat dissipation device 201 is too heavy, or the current is increased due to mechanical failure inside the motor (for example, fan blade jamming, abnormal rotation speed, etc.). When the current is too large, the power consumption of the heat dissipation device 201 is too high, which may cause excessive heat to be generated. If the heat is not dissipated in time, the equipment (such as a converter) may be damaged due to overheating. Overheating may cause the performance of electrical components (such as capacitors, power supply modules) to decrease, and even cause an electrical fire, resulting in equipment failure or serious safety accidents. In addition, when the current of one or more phases is too small, it may indicate that the rotation speed of the motor of the heat dissipation device 201 decreases, causing insufficient output wind power, which makes it difficult to effectively dissipate heat. At this time, the working efficiency of the heat dissipation device 201 is greatly reduced, and it cannot provide sufficient cooling effect for the equipment. If the equipment is in this state for a long time, the temperature of the equipment may be too high, which may cause the temperature of the internal circuit of the converter to be too high, thereby affecting the working stability of the electronic components, and even causing the equipment to fail or malfunction. Through the current detection device, when the current is too large or too small is detected, protective measures can be taken quickly, and the power supply circuit of the heat dissipation device 201 can be cut off in time, thereby reducing the long-term damage to the equipment caused by overheating, and ensuring that the equipment operates stably within a safe temperature range. Moreover, since the current detection device can detect three-phase current, any abnormal current of any phase will trigger a fault, ensuring accurate triggering of the fault.

[0038] Specifically, in the above embodiment, the current detection device is a device for monitoring the three-phase current state of the heat dissipation device 201, which includes a detection circuit 101, a first controllable switching device 102, and the like, for realizing rapid detection and response to abnormal current. Each detection circuit 101 corresponds to the detection of one phase of the three-phase current of the heat dissipation device 201, and converts the current signal into a level signal (first level signal or second level signal) for driving the subsequent control element. The first controllable switching device 102 is turned on or off according to the output level signal of the detection circuit 101, for controlling the on-off state of the control circuit. Three first controllable switching devices 102 (corresponding to one detection circuit 101 respectively) are arranged in series in the control circuit, and when any one of the first controllable switching devices 102 is turned off, the control circuit is turned off, thereby affecting the state of the power supply circuit of the heat dissipation device 201. The power supply circuit is a circuit for providing power to the heat dissipation device 201, and its on-off state is determined by the on-off state of the control circuit. As an example, it is assumed that the heat dissipation device 201 is a fan, and a power supply (which can be referred to as a fan power supply) for supplying power to the fan can be arranged in the power supply circuit.

[0039] The current detection device described above monitors the three-phase current of the heat dissipation device 201 through three detection circuits 101. Each detection circuit 101 collects the corresponding phase current signal and converts the signal into a first level signal or a second level signal. Under normal circumstances, all detection circuits 101 output the second level signal, which drives the corresponding first controllable switching device 102 to conduct, so that the control circuit remains closed and the power supply circuit of the heat dissipation device 201 is in an energized state. As an example, when one phase, two phases or three phases of current are abnormal, the power supply circuit can be disconnected according to whether the control circuit is disconnected for a certain period of time or the duration of the abnormal current meets the requirement of disconnecting the power supply circuit, in order to protect the safety of the heat dissipation device 201 and the safety of the converter.

[0040] By combining current detection with switching control, the current detection device described above can monitor the three-phase current state of the heat dissipation device 201 in real time and accurately determine the current abnormality. Its design ensures that any one or more phase current abnormalities will trigger a fault, reducing the risk of missed detection of single-point faults. By controlling the disconnection of the power supply circuit of the heat dissipation device 201, the safety hazards caused by abnormal current can be interrupted in time, ensuring the stable operation of the converter or other related equipment.

[0041] Referring to Figure 3 , Figure 3 is a structural block diagram of a detection circuit 101 provided by an embodiment of the present application.

[0042] As shown in Figure 3 , in some embodiments, the detection circuit 101 can include an inductive device 105 and a signal processing module 106. The inductive device 105 is used to induce an electrical signal corresponding to the one-phase current. The signal processing module 106 is used to process the electrical signal to output the first level signal or the second level signal.

[0043] The above embodiment does not limit the electrical signal, which may, for example, be a current signal or a voltage signal.

[0044] Referring to Figure 4 , Figure 4 is a structural block diagram of a signal processing module 106 provided by an embodiment of the present application.

[0045] As shown in Figure 4 , in some embodiments, the inductive device 105 can be a current transformer, and the electrical signal can be an alternating current signal. The signal processing module 106 can include a signal conversion unit 107 and a comparison unit. The signal conversion unit 107 is used to convert the alternating current signal into a direct current voltage signal. The comparison unit 108 is used to compare the voltage value corresponding to the direct current voltage signal with a target voltage value range to output the first level signal or the second level signal.

[0046] Referring to Figure 5 , Figure 5 is a structural block diagram of a comparison unit 108 provided by an embodiment of the present application.

[0047] As shown in Figure 5 some embodiments, the comparison unit 108 includes a first comparison device 109. The first comparison device 109 is configured to compare a voltage value of the direct current voltage signal with a target voltage value range, and output the first level signal indicating that the voltage value is within the target voltage value range, or output the second level signal indicating that the voltage value is not within the target voltage value range. In this embodiment, the on-off state of the power supply circuit of the heat dissipation device 201 is determined according to the disconnection time length of the control circuit. In this embodiment, if the first comparison device 109 outputs the first level signal, the control circuit is disconnected, and the on-off state of the power supply circuit is determined according to the disconnection time length of the control circuit. For example, when the disconnection time length is greater than a preset time length threshold, the power supply circuit is disconnected, or when the disconnection time length is not greater than the preset time length threshold, the power supply circuit is kept on.

[0048] Referring to Figure 6 , Figure 6 is another structural block diagram of a comparison unit 108 provided by an embodiment of the present application.

[0049] As shown in Figure 6As shown, in some embodiments, the comparison unit 108 includes a second comparison device 110 and a third comparison device 111. The second comparison device 110 compares the voltage value corresponding to the DC voltage signal with a target voltage range to output a normal current signal indicating that the voltage value is within the target voltage range, or an abnormal current signal indicating that the voltage value is not within the target voltage range. The third comparison device 111 compares the abnormal current duration corresponding to the abnormal current signal with a preset duration threshold to output a first level signal indicating that the abnormal current duration is greater than the preset duration threshold, or a second level signal indicating that the abnormal current duration is not greater than the preset duration threshold. The on / off state of the corresponding power supply circuit of the heat dissipation device 201 is determined based on the abnormal current duration. In this embodiment, if the second comparator 110 outputs an abnormal current signal, the control loop is not directly disconnected. Instead, the third comparator 111 determines the duration of the abnormal current. If the duration exceeds a preset duration threshold, the third comparator 111 outputs a first-level signal, disconnecting the control loop and the power supply loop. Alternatively, if the duration is not greater than the preset duration threshold, the third comparator 111 outputs a second-level signal, turning on the control loop and keeping the power supply loop on. If the second comparator 110 outputs a normal current signal, this can be considered as a case where the duration of the abnormal current is 0.

[0050] Both of the above control methods utilize the disconnection duration or current anomaly duration of the control loop for fault determination, respectively. Both methods can reduce the interference of short-term current fluctuations on equipment operation, thereby improving the fault tolerance and reliability of the system. For example, in applications such as wind power, the disconnection duration determination or current anomaly duration determination can protect against current surges caused by normal grid crossings within the national standard range. That is, if the disconnection duration or current anomaly duration does not reach the set time (e.g., a preset duration threshold), it is not considered a current anomaly, and the power supply circuit of the heat dissipation device 201 is not disconnected.

[0051] See Figure 7 , Figure 7 This is a structural block diagram of a signal conversion unit 107 provided in an embodiment of this application.

[0052] like Figure 7 As shown, in some embodiments, the signal conversion unit 107 may include a rectifier 112 and a converter 113. The rectifier 112 is used to rectify the AC current signal to obtain a DC current signal. The converter 113 is used to convert the DC current signal to obtain the DC voltage signal.

[0053] In some embodiments, the rectifying device 112 can be a rectifier bridge. The above embodiments do not limit the rectifier bridge, which can be in a full-bridge structure or a half-bridge structure, for example.

[0054] Referring to Figure 8 , Figure 8 is a structural block diagram of a conversion device 113 provided by an embodiment of the present application.

[0055] As shown in Figure 8 some embodiments, the conversion device 113 can be an operational amplifier 115. The operational amplifier 115 includes an input resistor 114 and an amplifier 115. The input resistor 114 is used to sense an input voltage signal corresponding to the direct current signal. The amplifier 115 is used to amplify the input voltage signal to obtain the direct current voltage signal.

[0056] In some embodiments, the current detection apparatus can be a current detection board. Since three-phase current can be detected, it can also be referred to as a three-phase current detection board.

[0057] For example, assuming that the heat dissipation device 201 is a fan and the first controllable switching device 102 is a relay. The current detection apparatus can access the three-phase current of the fan, and each phase current passes through a detection circuit 101. The comparison unit in the detection circuit 101 determines whether the phase current is in a normal range (for example, a target current value range). As an example, when the voltage value of the direct current voltage signal converted by the phase current is in the target voltage value range, it is determined that the phase current is in the normal range; when the voltage value of the direct current voltage signal converted by the phase current is not in the target voltage value range, it is determined that the phase current is not in the normal range. The normal range can be preselected or set, and the above embodiments do not limit it.

[0058] Two implementation modes of the comparison unit 108 will be described separately below.

[0059] In the first implementation, it is assumed that the comparison unit 108 includes a first comparison device 109. When all three phase currents of the fan are within the set normal range, the first comparison device 109 outputs a high-level signal (as an example of a second-level signal). The auxiliary contacts of the three relays after the detection circuit 101 can change from normally open to normally closed, the control circuit is turned on, and the controller 103 (e.g., ARM, DSP, or others) can receive the high-level signal. The controller 103 keeps the power supply circuit in the on state and outputs the fan's normal operating status information. When one or more phases of the fan's three-phase current abnormally exceed the normal range (i.e., are not within the normal range), the first comparison device 109 outputs a low-level signal (as an example of a first-level signal). The corresponding relays after the detection circuit 101 will not be activated, the controller 103 will not receive the high-level signal, and the determination is made by the duration of the control circuit's disconnection. If the disconnection duration exceeds a set value (e.g., a preset duration threshold), the controller 103 can issue a command (e.g., a first control command) to disconnect the fan power supply by controlling the second controllable switching device 104 (e.g., a contactor) in the power supply circuit. This achieves the purpose of monitoring the three-phase current to protect the fan and reports fault status information. ARM stands for Advanced RISC Machines, a processor architecture. DSP stands for Digital Signal Processor.

[0060] For example, such as Figure 1 As shown, the three-phase currents (A, B, and C) of the fan are connected to the three-phase current detection board through terminals. Each phase current is induced as an AC current signal on the secondary side by the corresponding current transformer. The AC current signal is rectified by the rectifier bridge to obtain a DC current signal. The input resistor 114 in the operational amplifier 115 induces a corresponding input voltage signal for the DC-AC signal. The amplifier 115 amplifies the input voltage signal by a target factor (the target factor can be pre-selected or specified) to obtain a DC voltage signal. The first comparator 109 compares the corresponding voltage value of the DC voltage signal with the target voltage range and outputs a first-level signal or a second-level signal to drive the subsequent relays KM1, KM2, and KM3. The auxiliary contacts of these three relays are connected in series in the control circuit. The controller 103 controls the on / off state of the contactor KM4 in the fan power supply circuit through the feedback signal obtained from the control circuit, thereby realizing the on / off state of the fan power supply circuit. As an example, when all relays KM1, KM2, and KM3 are turned on, the feedback signal received by the controller 103 is a high-level signal; when one or more of relays KM1, KM2, and KM3 are turned off, the feedback signal received by the controller 103 is a low-level signal.

[0061] As an example, the first comparison device 109 can set a target voltage value range, the lower threshold (i.e., the minimum value) of the target voltage value range is, for example, U1, and the upper threshold (i.e., the maximum value) is, for example, U2. U1, U2 can be flexibly set according to the actual application of the wind farm and experience, covering stable operation and locked-rotor conditions.

[0062] The first case is the normal operating condition. When the A, B, and C three-phase currents are all within the normal range, after rectification, operational amplification, and comparison, the corresponding voltage value U of the DC voltage signal converted by each phase current is within the range [U1, U2], the detection circuit 101 generates a high-level signal (as an example of the second level signal), and the relays KM1, KM2, and KM3 are attracted, and the three normally open contacts are closed, and the control circuit is turned on. The controller 103 receives the high-level signal, outputs the normal operation state information of the fan, and controls the contactor KM4 in the power supply circuit to be attracted, and the fan is in normal operation.

[0063] The second case is the abnormal current condition. When one or two of the A, B, and C three-phase currents, or even all three-phase currents are abnormal, after rectification, operational amplification, and comparison, the corresponding voltage value U of the DC voltage signal converted by the abnormal current is not within the range [U1, U2] (for example, lower than the lower limit value U1, or higher than the upper limit value U2), the abnormal current corresponding detection circuit 101 generates a low-level signal (as an example of the first level signal), and the corresponding relay in the latter stage is de-energized and opened, and the auxiliary contact is still normally open, and the control circuit is in an open state. The controller 103 cannot receive the high-level signal, and the controller 103 determines the open duration of the control circuit, and if the open duration is greater than the set time T1 (as an example of the preset duration threshold), the controller 103 outputs a disconnection instruction (as an example of the first control instruction) to the contactor KM4 in the power supply circuit, and outputs the fan fault state information, at which time the fan is stopped from being powered, and the fan is protected.

[0064] In the above embodiments, the current abnormal condition can be divided into two parts: external power supply and fan motor body. Among them, the corresponding current abnormal condition of external power supply includes high penetration, low penetration, open phase, etc. Among them, high penetration refers to the voltage of the power supply being higher than the normal working range, resulting in an increase in current. Excessive voltage may overload the internal components of the motor, increase the impedance of the current flowing through, and thus cause current abnormalities. Low penetration refers to the voltage of the power supply being lower than the normal working range, resulting in too small or unstable current. Low voltage may reduce the speed of the motor, resulting in poor heat dissipation of the fan, and may cause the motor to fail to start or work normally. Open phase refers to the loss or inability of a phase current in a three-phase power supply. Open phase will cause the fan motor to fail to work normally, which may reduce the speed of the fan or completely stop, affecting the heat dissipation effect, and even causing the motor to be damaged. The corresponding current abnormal condition of the fan motor body includes fan jam, rear coil short circuit, fan speed drop, etc. Among them, fan jam refers to the fan blades being unable to rotate normally due to mechanical failure (such as foreign matter being stuck or blade damage). This will cause the current to increase, and the fan will not be able to provide effective heat dissipation. The rear coil short circuit refers to the short circuit of the coil of the fan motor, resulting in excessive current or uneven current distribution, which may damage the motor winding and affect the performance of the motor. The fan speed drop refers to the fan speed drop due to motor failure or excessive load, etc., which affects the heat dissipation effect of the fan, and may cause the equipment to overheat.

[0065] In the second embodiment, it is assumed that the comparison unit 108 includes a second comparison device 110 and a third comparison device 111. When the three-phase current of the fan is within the set normal range, as an example, the second comparison device 110 outputs a high-level signal (as an example of a current normal signal), and the third comparison device 111 outputs a high-level signal (as an example of a second-level signal). The auxiliary contact of the three relays in the detection circuit 101 can be changed from normally open to normally closed, the control circuit is turned on, and the controller 103 can receive a high-level signal and output normal operation state information. When one or more of the three-phase current of the fan is abnormal and exceeds the normal range (i.e., not within the normal range), the second comparison device 110 outputs a low-level signal (as an example of a current abnormal signal), and the third comparison device 111 determines the duration of the current abnormality according to the received current abnormal signal. When the duration of the current abnormality is greater than the preset duration threshold, the third comparison device 111 outputs a low-level signal (as an example of a first-level signal), the corresponding relay in the detection circuit 101 will not be attracted, and the controller 103 will not receive a high-level signal. The controller 103 can issue an instruction (e.g., a first control instruction) to turn off the second controllable switching device 104 (e.g., a contactor) in the power supply circuit to cut off the power supply of the fan, achieve the purpose of monitoring the three-phase current to protect the fan, and report the fault state information.

[0066] The embodiment of the present application further provides a control system, which comprises any of the current detection devices and a controller 103. The controller 103 is configured to receive the first level signal or the second level signal, and output a first control instruction for disconnecting a corresponding power supply loop of the heat dissipation device 201, or output a second control instruction for keeping the power supply loop on.

[0067] In some embodiments, the control system can further comprise a second controllable switching device 104 in the power supply loop, and the second controllable switching device 104 is configured to disconnect the power supply loop upon receiving the first control instruction, or keep the power supply loop on upon receiving the second control instruction.

[0068] The above embodiment does not limit the second controllable switching device 104, which can include one or more of a relay, a switch, a contactor and a circuit breaker, for example. In some embodiments, the second controllable switching device 104 can be a contactor.

[0069] In some embodiments, the controller 103 is further configured to output fault state information corresponding to the first control instruction, or output normal operation state information corresponding to the second control instruction.

[0070] It can be understood that the specific examples in the present application are only for helping those skilled in the art to better understand the embodiments of the present application, and not to limit the protection scope of the present application.

[0071] It can be understood that the various embodiments described in the present application can be implemented alone or in combination, and the present application does not limit this.

[0072] Unless otherwise defined, all technical and scientific terms used in the present application have the same meanings as those commonly understood by those skilled in the art to which the present application belongs. The terms used in the present application are only for the purpose of describing specific embodiments, and are not intended to limit the scope of the present application. The term "and / or" used in the present application includes any and all combinations of one or more of the listed terms. The singular forms "a", "an" and "the" used in the present application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0073] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described embodiments can refer to the corresponding processes in other embodiments, which will not be described here.

[0074] In several embodiments provided in the present application, it should be understood that the disclosed system, device and method can be implemented by other ways. For example, the device embodiments described above are merely illustrative, for example, the division of units is only a logical function division, and actual implementation can have another division, for example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0075] The units described as separate components can or can not be physically separated, and the components shown as units can or can not be physical units, that is, they can be located in one place, or they can be distributed on multiple network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the technical solutions of the present application.

[0076] In addition, each functional unit in each embodiment of the present application can be integrated into a processing unit, or each unit can exist physically, or two or more units can be integrated into one unit.

[0077] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A current detection device, characterized by, The current detection device comprises three detection loops and first controllable switching devices corresponding to each detection loop; The three first controllable switching devices are arranged in series in a control loop; Each detection loop is used for detecting one phase current in three-phase currents of the heat dissipation device, and generating a first level signal corresponding to the one phase current, the first level signal being used for turning off the first controllable switching device corresponding to the detection loop, or generating a second level signal corresponding to the one phase current, the second level signal being used for turning on the first controllable switching device corresponding to the detection loop; When at least one first controllable switching device is turned off, the control loop is in an off state, and the on-off state of the power supply loop corresponding to the heat dissipation device is determined according to the on-off state of the control loop.

2. The current detection device according to claim 1, wherein The detection loop comprises: a sensing device for sensing an electrical signal corresponding to the one phase current; a signal processing module for processing the electrical signal to output the first level signal or the second level signal.

3. The current detection device according to claim 2, wherein The sensing device is a current transformer, and the electrical signal is an alternating current signal; The signal processing module comprises a signal conversion unit and a comparison unit; the signal conversion unit is used for converting the alternating current signal into a direct current voltage signal; and the comparison unit is used for comparing a voltage value corresponding to the direct current voltage signal with a target voltage value range to output the first level signal or the second level signal.

4. The current detection device according to claim 3, wherein The comparison unit comprises a first comparison device; The first comparison device is used for comparing the voltage value corresponding to the direct current voltage signal with the target voltage value range to output the first level signal indicating that the voltage value is within the target voltage value range, or output the second level signal indicating that the voltage value is not within the target voltage value range; The on-off state of the power supply loop corresponding to the heat dissipation device is determined according to the off duration of the control loop.

5. The current detection device according to claim 3, wherein The comparison unit comprises a second comparison device and a third comparison device; The second comparison device is used for comparing the voltage value corresponding to the direct current voltage signal with the target voltage value range to output a current normal signal indicating that the voltage value is within the target voltage value range, or output a current abnormal signal indicating that the voltage value is not within the target voltage value range; The third comparison device compares a current abnormal duration corresponding to the current abnormal signal with a preset duration threshold to output the first level signal indicating that the current abnormal duration is greater than the preset duration threshold, or output the second level signal indicating that the current abnormal duration is not greater than the preset duration threshold; The on-off state of the power supply loop corresponding to the heat dissipation device is determined according to the current abnormal duration.

6. The current detection device according to claim 3, wherein The signal conversion unit comprises: a rectifying device for rectifying the alternating current signal to obtain a direct current signal; a conversion device for converting the direct current signal to obtain the direct current voltage signal.

7. The current detection device according to claim 6, wherein The conversion device is an operational amplifier device, and the operational amplifier device comprises: an input resistor for sensing an input voltage signal corresponding to the direct current signal; an amplifier for amplifying the input voltage signal to obtain the direct current voltage signal.

8. The current detection device according to claim 1, wherein The first controllable switching device comprises one or more of a relay, a switch, a contactor, a circuit breaker, an IGBT and a MOSFET.

9. A control system characterized by, The control system comprises: the current detection device of any one of claims 1 to 8; a controller for receiving the first level signal or the second level signal to output a first control instruction for turning off a corresponding power supply loop of the heat dissipation device, or output a second control instruction for keeping the power supply loop on.

10. The control system of claim 9, wherein, The control system further comprises: a second controllable switching device in the power supply loop for turning off the power supply loop upon receiving the first control instruction, or keeping the power supply loop on upon receiving the second control instruction.

11. The control system of claim 10, wherein, The second controllable switching device comprises one or more of a relay, a switch, a contactor and a circuit breaker.

12. The control system of claim 9, wherein, The controller is further configured to output fault state information corresponding to the first control instruction, or output normal operation state information corresponding to the second control instruction.

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